Preservation of renal blood flow by the antioxidant EUK-134 in LPS-treated pigs.

PubMed

Magder, Sheldon; Parthenis, Dimitrios G; Ghouleh, Imad Al

2015-03-25

Sepsis is associated with an increase in reactive oxygen species (ROS), however, the precise role of ROS in the septic process remains unknown. We hypothesized that treatment with EUK-134 (manganese-3-methoxy N,N'-bis(salicyclidene)ethylene-diamine chloride), a compound with superoxide dismutase and catalase activity, attenuates the vascular manifestations of sepsis in vivo. Pigs were instrumented to measure cardiac output and blood flow in renal, superior mesenteric and femoral arteries, and portal vein. Animals were treated with saline (control), lipopolysaccharide (LPS; 10 µg·kg-1·h-1), EUK-134, or EUK-134 plus LPS. Results show that an LPS-induced increase in pulmonary artery pressure (PAP) as well as a trend towards lower blood pressure (BP) were both attenuated by EUK-134. Renal blood flow decreased with LPS whereas superior mesenteric, portal and femoral flows did not change. Importantly, EUK-134 decreased the LPS-induced fall in renal blood flow and this was associated with a corresponding decrease in LPS-induced protein nitrotyrosinylation in the kidney. PO2, pH, base excess and systemic vascular resistance fell with LPS and were unaltered by EUK-134. EUK-134 also had no effect on LPS-associated increase in CO. Interestingly, EUK-134 alone resulted in higher CO, BP, PAP, mean circulatory filling pressure, and portal flow than controls. Taken together, these data support a protective role for EUK-134 in the renal circulation in sepsis.

Genetic Determinants of Intrinsic Colistin Tolerance in Acinetobacter baumannii

PubMed Central

Hood, M. Indriati; Becker, Kyle W.; Roux, Christelle M.; Dunman, Paul M.

2013-01-01

Acinetobacter baumannii is a leading cause of multidrug-resistant infections worldwide. This organism poses a particular challenge due to its ability to acquire resistance to new antibiotics through adaptation or mutation. This study was undertaken to determine the mechanisms governing the adaptability of A. baumannii to the antibiotic colistin. Screening of a transposon mutant library identified over 30 genes involved in inducible colistin resistance in A. baumannii. One of the genes identified was lpsB, which encodes a glycosyltransferase involved in lipopolysaccharide (LPS) synthesis. We demonstrate that loss of LpsB function results in increased sensitivity to both colistin and cationic antimicrobial peptides of the innate immune system. Moreover, LpsB is critical for pathogenesis in a pulmonary model of infection. Taken together, these data define bacterial processes required for intrinsic colistin tolerance in A. baumannii and underscore the importance of outer membrane structure in both antibiotic resistance and the pathogenesis of A. baumannii. PMID:23230287

Mass Analyzers Facilitate Research on Addiction

NASA Technical Reports Server (NTRS)

2012-01-01

The famous go/no go command for Space Shuttle launches comes from a place called the Firing Room. Located at Kennedy Space Center in the Launch Control Center (LCC), there are actually four Firing Rooms that take up most of the third floor of the LCC. These rooms comprise the nerve center for Space Shuttle launch and processing. Test engineers in the Firing Rooms operate the Launch Processing System (LPS), which is a highly automated, computer-controlled system for assembly, checkout, and launch of the Space Shuttle. LPS monitors thousands of measurements on the Space Shuttle and its ground support equipment, compares them to predefined tolerance levels, and then displays values that are out of tolerance. Firing Room operators view the data and send commands about everything from propellant levels inside the external tank to temperatures inside the crew compartment. In many cases, LPS will automatically react to abnormal conditions and perform related functions without test engineer intervention; however, firing room engineers continue to look at each and every happening to ensure a safe launch. Some of the systems monitored during launch operations include electrical, cooling, communications, and computers. One of the thousands of measurements derived from these systems is the amount of hydrogen and oxygen inside the shuttle during launch.

The Quality Control Algorithms Used in the Creation of NASA Kennedy Space Center Lightning Protection System Towers Meteorological Database

NASA Technical Reports Server (NTRS)

Orcutt, John M.; Brenton, James C.

2016-01-01

An accurate database of meteorological data is essential for designing any aerospace vehicle and for preparing launch commit criteria. Meteorological instrumentation were recently placed on the three Lightning Protection System (LPS) towers at Kennedy Space Center (KSC) launch complex 39B (LC-39B), which provide a unique meteorological dataset existing at the launch complex over an extensive altitude range. Data records of temperature, dew point, relative humidity, wind speed, and wind direction are produced at 40, 78, 116, and 139 m at each tower. The Marshall Space Flight Center Natural Environments Branch (EV44) received an archive that consists of one-minute averaged measurements for the period of record of January 2011 - April 2015. However, before the received database could be used EV44 needed to remove any erroneous data from within the database through a comprehensive quality control (QC) process. The QC process applied to the LPS towers' meteorological data is similar to other QC processes developed by EV44, which were used in the creation of meteorological databases for other towers at KSC. The QC process utilized in this study has been modified specifically for use with the LPS tower database. The QC process first includes a check of each individual sensor. This check includes removing any unrealistic data and checking the temporal consistency of each variable. Next, data from all three sensors at each height are checked against each other, checked against climatology, and checked for sensors that erroneously report a constant value. Then, a vertical consistency check of each variable at each tower is completed. Last, the upwind sensor at each level is selected to minimize the influence of the towers and other structures at LC-39B on the measurements. The selection process for the upwind sensor implemented a study of tower-induced turbulence. This paper describes in detail the QC process, QC results, and the attributes of the LPS towers meteorological database.

Participation of hypothalamic CB1 receptors in reproductive axis disruption during immune challenge.

PubMed

Surkin, P N; Di Rosso, M E; Correa, F; Elverdin, J C; Genaro, A M; De Laurentiis, A; Fernández-Solari, J

2017-08-01

Immune challenge inhibits reproductive function and endocannabinoids (eCB) modulate sexual hormones. However, no studies have been performed to assess whether the eCB system mediates the inhibition of hormones that control reproduction as a result of immune system activation during systemic infections. For that reason, we evaluated the participation of the hypothalamic cannabinoid receptor CB1 on the hypothalamic-pituitary-gonadal (HPG) axis activity in rats submitted to immune challenge. Male adult rats were treated i.c.v. administration with a CB1 antagonist/inverse agonist (AM251) (500 ng/5 μL), followed by an i.p. injection of lipopolysaccharide (LPS) (5 mg/kg) 15 minutes later. Plasmatic, hypothalamic and adenohypophyseal pro-inflammatory cytokines, hormones and neuropeptides were assessed 90 or 180 minutes post-LPS. The plasma concentration of tumour necrosis factor α and adenohypophyseal mRNA expression of Tnfα and Il1β increased 90 and 180 minutes post i.p. administration of LPS. However, cytokine mRNA expression in the hypothalamus increased only 180 minutes post-LPS, suggesting an inflammatory delay in this organ. CB1 receptor blockade with AM251 increased LPS inflammatory effects, particularly in the hypothalamus. LPS also inhibited the HPG axis by decreasing gonadotrophin-releasing hormone hypothalamic content and plasma levels of luteinising hormone and testosterone. These disruptor effects were accompanied by decreased hypothalamic Kiss1 mRNA expression and prostaglandin E2 content, as well as by increased gonadotrophin-inhibitory hormone (Rfrp3) mRNA expression. All these disruptive effects were prevented by the presence of AM251. In summary, our results suggest that, in male rats, eCB mediate immune challenge-inhibitory effects on reproductive axis at least partially via hypothalamic CB1 activation. In addition, this receptor also participates in homeostasis recovery by modulating the inflammatory process taking place after LPS administration. © 2017 British Society for Neuroendocrinology.

Software Reliability Issues Concerning Large and Safety Critical Software Systems

NASA Technical Reports Server (NTRS)

Kamel, Khaled; Brown, Barbara

1996-01-01

This research was undertaken to provide NASA with a survey of state-of-the-art techniques using in industrial and academia to provide safe, reliable, and maintainable software to drive large systems. Such systems must match the complexity and strict safety requirements of NASA's shuttle system. In particular, the Launch Processing System (LPS) is being considered for replacement. The LPS is responsible for monitoring and commanding the shuttle during test, repair, and launch phases. NASA built this system in the 1970's using mostly hardware techniques to provide for increased reliability, but it did so often using custom-built equipment, which has not been able to keep up with current technologies. This report surveys the major techniques used in industry and academia to ensure reliability in large and critical computer systems.

Sildenafil (Viagra(®)) prevents and restores LPS-induced inflammation in astrocytes.

PubMed

de Santana Nunes, Ana Karolina; Rapôso, Catarina; Björklund, Ulrika; da Cruz-Höfling, Maria Alice; Peixoto, Christina Alves; Hansson, Elisabeth

2016-09-06

Astrocytes are effectively involved in the pathophysiological processes in the central nervous system (CNS) and may contribute to or protect against development of inflammatory and degenerative diseases. Sildenafil is a potent and selective phosphodiesterase-5 (PDE-5) inhibitor, which induces cyclic GMP accumulation. However, the mechanisms of actions on glial cells are not clear. The aim of the present work is to evaluate the role of sildenafil in lipopolysaccharide (LPS)-stimulated astrocytes. The cytoskeleton integrity and Ca(2+) waves were assessed as indicators of inflammatory state. Two main groups were done: (A) one prevention and (B) one restoration. Each of these groups: A1: control; A2: LPS for 24h; A3: sildenafil 1 or 10μM for 4h and then sildenafil 1 or 10μM+LPS for 24h. B1: control; B2: LPS for 24h; B3: LPS for 24h and then LPS+sildenafil 1 or 10μM for 24h. Cytoskeleton integrity was analyzed through GFAP immunolabeling and actin labeling with an Alexa 488-conjugated phalloidin probe. Calcium responses were assessed through a Ca(2+)-sensitive fluorophore Fura-2/AM. The results show that both preventive and restorative treatments with sildenafil (in both concentrations) reduced the Ca(2+) responses in intensity and induced a more organized actin fiber pattern, compared to LPS treated cells. This work demonstrated for the first time that astrocytes are a key part of the sildenafil protective effects in the CNS. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

[Verbal communication disorders and language disorders in cortical dementias (I). The current state of the art in research].

PubMed

Benedet, M J

This is the first part of a research work into primary and secondary language disorders (LD) in the stages of minimum to mild pathological deterioration in the degenerative process of cortical dementias. AIMS. In this first part, in the light of recent models of symbolic computation of language processing, we review the most significant publications on the subject matter. We begin with an introduction to the historical development of the approaches used to deal with the subject. Following that, we briefly describe the components of the language processing system (LPS) in the light of symbolic computation models. We then analyse the publications dealing with those models. Our aim was to determine whether the LD reported in those publications are the result of a primary involvement of any of the LPS components, or whether they are only the result of disorders affecting other components of the cognitive system. In this case, the supposed LD would be secondary and thus a communication, but not language, disorder. Despite the important variations from one individual to another that have been systematically observed by different authors, it seems that only LD belonging to so called primary progressive aphasia are actually cases of this disorder. In all the other dementias in the above mentioned stages of the development process these disorders are secondary to the involvement of other subsystems of the LPS.

miR-Let7A Modulates Autophagy Induction in LPS-Activated Microglia

PubMed Central

Song, Juhyun; Oh, Yumi

2015-01-01

Microglia regulate the secretion of various immunomediators in central nervous system diseases. Microglial autophagy is the crucial process for cell's survival and cytokine productions. Recent studies have reported that several microRNAs are involved in the autophagy system. miR-Let7A is such a microRNA that plays a role in various inflammation responses, and is magnified as a key modulator particularly in the autophagy system. In present study, we investigated whether miR-Let7A is involved in autophagy in activating microglia. Overexpression of miR-Let7A in LPS-stimulated BV2 microglial cells promoted the induction of the autophagy related factors such as LC3II, Beclin1, and ATG3. Our results suggest a potential role of miR-Let7A in the autophagy process of microglia during CNS inflammation. PMID:26113790

High-throughput living cell-based optical biosensor for detection of bacterial lipopolysaccharide (LPS) using a red fluorescent protein reporter system.

PubMed

Jiang, Hui; Jiang, Donglei; Shao, Jingdong; Sun, Xiulan; Wang, Jiasheng

2016-11-14

Due to the high toxicity of bacterial lipopolysaccharide (LPS), resulting in sepsis and septic shock, two major causes of death worldwide, significant effort is directed toward the development of specific trace-level LPS detection systems. Here, we report sensitive, user-friendly, high-throughput LPS detection in a 96-well microplate using a transcriptional biosensor system, based on 293/hTLR4A-MD2-CD14 cells that are transformed by a red fluorescent protein (mCherry) gene under the transcriptional control of an NF-κB response element. The recognition of LPS activates the biosensor cell, TLR4, and the co-receptor-induced NF-κB signaling pathway, which results in the expression of mCherry fluorescent protein. The novel cell-based biosensor detects LPS with specificity at low concentration. The cell-based biosensor was evaluated by testing LPS isolated from 14 bacteria. Of the tested bacteria, 13 isolated Enterobacteraceous LPSs with hexa-acylated structures were found to increase red fluorescence and one penta-acylated LPS from Pseudomonadaceae appeared less potent. The proposed biosensor has potential for use in the LPS detection in foodstuff and biological products, as well as bacteria identification, assisting the control of foodborne diseases.

Validity of the Catapult ClearSky T6 Local Positioning System for Team Sports Specific Drills, in Indoor Conditions

PubMed Central

Luteberget, Live S.; Spencer, Matt; Gilgien, Matthias

2018-01-01

Aim: The aim of the present study was to determine the validity of position, distance traveled and instantaneous speed of team sport players as measured by a commercially available local positioning system (LPS) during indoor use. In addition, the study investigated how the placement of the field of play relative to the anchor nodes and walls of the building affected the validity of the system. Method: The LPS (Catapult ClearSky T6, Catapult Sports, Australia) and the reference system [Qualisys Oqus, Qualisys AB, Sweden, (infra-red camera system)] were installed around the field of play to capture the athletes' motion. Athletes completed five tasks, all designed to imitate team-sports movements. The same protocol was completed in two sessions, one with an assumed optimal geometrical setup of the LPS (optimal condition), and once with a sub-optimal geometrical setup of the LPS (sub-optimal condition). Raw two-dimensional position data were extracted from both the LPS and the reference system for accuracy assessment. Position, distance and speed were compared. Results: The mean difference between the LPS and reference system for all position estimations was 0.21 ± 0.13 m (n = 30,166) in the optimal setup, and 1.79 ± 7.61 m (n = 22,799) in the sub-optimal setup. The average difference in distance was below 2% for all tasks in the optimal condition, while it was below 30% in the sub-optimal condition. Instantaneous speed showed the largest differences between the LPS and reference system of all variables, both in the optimal (≥35%) and sub-optimal condition (≥74%). The differences between the LPS and reference system in instantaneous speed were speed dependent, showing increased differences with increasing speed. Discussion: Measures of position, distance, and average speed from the LPS show low errors, and can be used confidently in time-motion analyses for indoor team sports. The calculation of instantaneous speed from LPS raw data is not valid. To enhance instantaneous speed calculation the application of appropriate filtering techniques to enhance the validity of such data should be investigated. For all measures, the placement of anchor nodes and the field of play relative to the walls of the building influence LPS output to a large degree. PMID:29670530

Lidocaine Prevents Oxidative Stress-Induced Endothelial Dysfunction of the Systemic Artery in Rats With Intermittent Periodontal Inflammation.

PubMed

Saito, Takumi; Yamamoto, Yasuhiro; Feng, Guo-Gang; Kazaoka, Yoshiaki; Fujiwara, Yoshihiro; Kinoshita, Hiroyuki

2017-06-01

Periodontal inflammation causes endothelial dysfunction of the systemic artery. However, it is unknown whether the use of local anesthetics during painful dental procedures alleviates periodontal inflammation and systemic endothelial function. This study was designed to examine whether the gingival or systemic injection of lidocaine prevents oxidative stress-induced endothelial dysfunction of the systemic artery in rats with intermittent periodontal inflammation caused by lipopolysaccharides (LPS). Some rats received 1500 µg LPS injections to the gingiva during a week interval from the age of 8 to 11 weeks (LPS group). Lidocaine (3 mg/kg), LPS + lidocaine (3 mg/kg), LPS + lidocaine (1.5 mg/kg), and LPS + lidocaine (3 mg/kg, IP) groups simultaneously received gingival 1.5 or 3 mg/kg or IP 3 mg/kg injection of lidocaine on the same schedule as the gingival LPS. Isolated aortas or mandibles were subjected to the evaluation of histopathologic change, isometric force recording, reactive oxygen species, and Western immunoblotting. Mean blood pressure and heart rate did not differ among the control, LPS, LPS + lidocaine (3 mg/kg), and lidocaine (3 mg/kg) groups. LPS application reduced acetylcholine (ACh, 10 to 10 mol/L)-induced relaxation (29% difference at ACh 3 × 10 mol/L, P = .01), which was restored by catalase. Gingival lidocaine (1.5 and 3 mg/kg) dose dependently prevented the endothelial dysfunction caused by LPS application (24.5%-31.1% difference at ACh 3 × 10 mol/L, P = .006 or .001, respectively). Similar to the gingival application, the IP injection of lidocaine (3 mg/kg) restored the ACh-induced dilation of isolated aortas from rats with the LPS application (27.5% difference at ACh 3 × 10 mol/L, P < .001). Levels of reactive oxygen species were double in aortas from the LPS group (P < .001), whereas the increment was abolished by polyethylene glycol-catalase, gingival lidocaine (3 mg/kg), or the combination. The LPS induced a 4-fold increase in the protein expression of tumor necrosis factor-α in the periodontal tissue (P < .001), whereas the lidocaine (3 mg/kg) coadministration partly reduced the levels. Lidocaine application also decreased the protein expression of the nicotinamide adenine dinucleotide phosphate oxidase subunit p47phox, which was enhanced by the gingival LPS (5.6-fold increase; P < .001). Lidocaine preserved the aortic endothelial function through a decrease in arterial reactive oxygen species produced by nicotinamide adenine dinucleotide phosphate oxidase and periodontal tumor necrosis factor-α levels in rats with periodontal inflammation. These results suggest the beneficial effect of the gingival application of local anesthetics on the treatment of periodontal diseases on endothelial function of systemic arteries.

SOX6 and PDCD4 enhance cardiomyocyte apoptosis through LPS-induced miR-499 inhibition.

PubMed

Jia, Zhuqing; Wang, Jiaji; Shi, Qiong; Liu, Siyu; Wang, Weiping; Tian, Yuyao; Lu, Qin; Chen, Ping; Ma, Kangtao; Zhou, Chunyan

2016-02-01

Sepsis-induced cardiac apoptosis is one of the major pathogenic factors in myocardial dysfunction. As it enhances numerous proinflammatory factors, lipopolysaccharide (LPS) is considered the principal mediator in this pathological process. However, the detailed mechanisms involved are unclear. In this study, we attempted to explore the mechanisms involved in LPS-induced cardiomyocyte apoptosis. We found that LPS stimulation inhibited microRNA (miR)-499 expression and thereby upregulated the expression of SOX6 and PDCD4 in neonatal rat cardiomyocytes. We demonstrate that SOX6 and PDCD4 are target genes of miR-499, and they enhance LPS-induced cardiomyocyte apoptosis by activating the BCL-2 family pathway. The apoptosis process enhanced by overexpression of SOX6 or PDCD4, was rescued by the cardiac-abundant miR-499. Overexpression of miR-499 protected the cardiomyocytes against LPS-induced apoptosis. In brief, our results demonstrate the existence of a miR-499-SOX6/PDCD4-BCL-2 family pathway in cardiomyocytes in response to LPS stimulation.

Functional programming of the autonomic nervous system by early life immune exposure: implications for anxiety.

PubMed

Sominsky, Luba; Fuller, Erin A; Bondarenko, Evgeny; Ong, Lin Kooi; Averell, Lee; Nalivaiko, Eugene; Dunkley, Peter R; Dickson, Phillip W; Hodgson, Deborah M

2013-01-01

Neonatal exposure of rodents to an immune challenge alters a variety of behavioural and physiological parameters in adulthood. In particular, neonatal lipopolysaccharide (LPS; 0.05 mg/kg, i.p.) exposure produces robust increases in anxiety-like behaviour, accompanied by persistent changes in hypothalamic-pituitary-adrenal (HPA) axis functioning. Altered autonomic nervous system (ANS) activity is an important physiological contributor to the generation of anxiety. Here we examined the long term effects of neonatal LPS exposure on ANS function and the associated changes in neuroendocrine and behavioural indices. ANS function in Wistar rats, neonatally treated with LPS, was assessed via analysis of tyrosine hydroxylase (TH) in the adrenal glands on postnatal days (PNDs) 50 and 85, and via plethysmographic assessment of adult respiratory rate in response to mild stress (acoustic and light stimuli). Expression of genes implicated in regulation of autonomic and endocrine activity in the relevant brain areas was also examined. Neonatal LPS exposure produced an increase in TH phosphorylation and activity at both PNDs 50 and 85. In adulthood, LPS-treated rats responded with increased respiratory rates to the lower intensities of stimuli, indicative of increased autonomic arousal. These changes were associated with increases in anxiety-like behaviours and HPA axis activity, alongside altered expression of the GABA-A receptor α2 subunit, CRH receptor type 1, CRH binding protein, and glucocorticoid receptor mRNA levels in the prefrontal cortex, hippocampus and hypothalamus. The current findings suggest that in addition to the commonly reported alterations in HPA axis functioning, neonatal LPS challenge is associated with a persistent change in ANS activity, associated with, and potentially contributing to, the anxiety-like phenotype. The findings of this study reflect the importance of changes in the perinatal microbial environment on the ontogeny of physiological processes.

Functional Programming of the Autonomic Nervous System by Early Life Immune Exposure: Implications for Anxiety

PubMed Central

Sominsky, Luba; Fuller, Erin A.; Bondarenko, Evgeny; Ong, Lin Kooi; Averell, Lee; Nalivaiko, Eugene; Dunkley, Peter R.; Dickson, Phillip W.; Hodgson, Deborah M.

2013-01-01

Neonatal exposure of rodents to an immune challenge alters a variety of behavioural and physiological parameters in adulthood. In particular, neonatal lipopolysaccharide (LPS; 0.05 mg/kg, i.p.) exposure produces robust increases in anxiety-like behaviour, accompanied by persistent changes in hypothalamic-pituitary-adrenal (HPA) axis functioning. Altered autonomic nervous system (ANS) activity is an important physiological contributor to the generation of anxiety. Here we examined the long term effects of neonatal LPS exposure on ANS function and the associated changes in neuroendocrine and behavioural indices. ANS function in Wistar rats, neonatally treated with LPS, was assessed via analysis of tyrosine hydroxylase (TH) in the adrenal glands on postnatal days (PNDs) 50 and 85, and via plethysmographic assessment of adult respiratory rate in response to mild stress (acoustic and light stimuli). Expression of genes implicated in regulation of autonomic and endocrine activity in the relevant brain areas was also examined. Neonatal LPS exposure produced an increase in TH phosphorylation and activity at both PNDs 50 and 85. In adulthood, LPS-treated rats responded with increased respiratory rates to the lower intensities of stimuli, indicative of increased autonomic arousal. These changes were associated with increases in anxiety-like behaviours and HPA axis activity, alongside altered expression of the GABA-A receptor α2 subunit, CRH receptor type 1, CRH binding protein, and glucocorticoid receptor mRNA levels in the prefrontal cortex, hippocampus and hypothalamus. The current findings suggest that in addition to the commonly reported alterations in HPA axis functioning, neonatal LPS challenge is associated with a persistent change in ANS activity, associated with, and potentially contributing to, the anxiety-like phenotype. The findings of this study reflect the importance of changes in the perinatal microbial environment on the ontogeny of physiological processes. PMID:23483921

Protective effects of tryptophan on neuro-inflammation in rats after administering lipopolysaccharide.

PubMed

Del Angel-Meza, A R; Dávalos-Marín, A J; Ontiveros-Martinez, L L; Ortiz, G G; Beas-Zarate, C; Chaparro-Huerta, V; Torres-Mendoza, B M; Bitzer-Quintero, O K

2011-06-01

Tryptophan (TRP), which plays an important role in immune system regulation, protein synthesis, serotonin (5-HT) and melatonin production, is a potent endogenous free radical scavenger and antioxidant. The aim of this work was to determine the efficacy of TRP in neuro-inflammation induced by systemic administration of lipopolysacharide (LPS, 20mg/kg) which promotes the synthesis of free radical (LPO: MDA and 4-HDA), and pro-inflammatory cytokine Interferon-γ (IFN-γ) in different brain regions (cerebral cortex and hippocampus) of rats. Experiments were performed on adult female, pregnant and lactating rats fed with a diet of TRP content (0.5mg/100g protein), cerebral cortex and hippocampus were evaluated for lipid peroxidation (LPO) products, nitrites, nitrates and plasmatic concentration of IFN-γ. LPO levels in LPS+TRP groups were significantly decreased than that obtained in the LPS group. However, there were no observed differences in plasmatic levels of nitrites and nitrates as well as IFN-γ, neither in the cerebral cortex or hippocampus. The TRP has protective effect in the oxidative damage in a model of endotoxic shock in the breading nurslings induced by the systemic administration of LPS, acting as a scavenger of free radicals. So, it can be proposed as an innocuous protector agent in the endotoxic shock process. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Influence of Periodontal Therapy on Systemic Lipopolysaccharides in Children with Localized Aggressive Periodontitis.

PubMed

Kalash, D; Vovk, A; Huang, H; Aukhil, I; Wallet, S M; Shaddox, L M

2015-01-01

A previous study has shown that children with localized aggressive periodontitis (LAP) demonstrate a lipopolysaccharide (LPS) hyper-responsiveness in addition to elevated levels of systemic LPS when compared to periodontally healthy children. The purpose of this study was to evaluate whether periodontal therapy modulates systemic lipopolysaccharide levels and whether these levels may influence clinical outcomes. Peripheral blood samples and clinical parameters (probing depth [PD], clinical attachment levels [CAL], percent sites greater than four mm, bleeding on probing [BoP], and visible plaque [P]) were collected from 29 LAP patients prior to and at three, six, and 12 months following scaling and root planning and systemic antibiotics. Serum LPS levels were quantified using a chromogenic assay. Twenty-five patients were compliant with the prescribed antibiotic treatment and demonstrated a significant reduction in LPS as well as overall PD, CAL, and plaque at all time points post-therapy. Additionally LPS reductions correlated with reductions in PD, CAL, and plaque. Localized aggressive periodontitis therapy with antibiotics plays an important role in reducing systemic lipopolysaccharide levels. Since LPS is a key mediator of the LAP hyperinflammatory response, its systemic reduction is especially important for the successful management of these children.

Adulthood Exposure to Lipopolysaccharide Exacerbates the Neurotoxic and Inflammatory Effects of Rotenone in the Substantia Nigra

PubMed Central

Huang, Chun; Zhu, Li; Li, Huan; Shi, Fu-Guo; Wang, Guo-Qing; Wei, Yi-Zheng; Liu, Jie; Zhang, Feng

2017-01-01

Parkinson’s disease (PD) is the second most neurodegenerative disorder with a regional decrease of dopamine (DA) neurons in the substantia nigra (SN). Despite intense exploration, the etiology of PD progressive process remains unclear. This study was to investigate the synergistic effects of systemic inflammation of lipopolysaccharide (LPS) and neurotoxicity of rotenone (ROT) on exacerbating DA neuron lesion. Male SD adulthood rats received a single intraperitoneal injection of LPS. Seven months later, rats were subcutaneously given ROT five times a week for consecutive 4 weeks. Rat behavior changes were assessed via rotarod and open-field tests. Brain SN was immunostained to evaluate DA neuronal loss and microglia activation. Striatum DA and its metabolites levels were determined by high performance liquid chromatography (HPLC) coupled with electrochemistry. The protein levels of α-synuclein (α-Syn), inflammatory factors and mitogen-activated protein kinase (MAPK) pathway activation were detected by western blotting analysis. Results indicated that no significant difference between the control and LPS alone groups was shown. Compared with ROT alone group, LPS combined with ROT significantly reduced motor activity and induced SN DA neurons loss accompanied by the decreased contents of striatum DA and its metabolites. Furthermore, LPS together with ROT enhanced microglia activation and the increased expressions of α-Syn and inflammatory factors and also MAPK signaling pathway activation. However, LPS alone had no significant effects on the above parameters. These findings suggest that adulthood exposure to LPS exacerbates the neurotoxic and inflammatory effects of ROT in the SN. PMID:28533741

Lightweight Provenance Service for High-Performance Computing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dai, Dong; Chen, Yong; Carns, Philip

Provenance describes detailed information about the history of a piece of data, containing the relationships among elements such as users, processes, jobs, and workflows that contribute to the existence of data. Provenance is key to supporting many data management functionalities that are increasingly important in operations such as identifying data sources, parameters, or assumptions behind a given result; auditing data usage; or understanding details about how inputs are transformed into outputs. Despite its importance, however, provenance support is largely underdeveloped in highly parallel architectures and systems. One major challenge is the demanding requirements of providing provenance service in situ. Themore » need to remain lightweight and to be always on often conflicts with the need to be transparent and offer an accurate catalog of details regarding the applications and systems. To tackle this challenge, we introduce a lightweight provenance service, called LPS, for high-performance computing (HPC) systems. LPS leverages a kernel instrument mechanism to achieve transparency and introduces representative execution and flexible granularity to capture comprehensive provenance with controllable overhead. Extensive evaluations and use cases have confirmed its efficiency and usability. We believe that LPS can be integrated into current and future HPC systems to support a variety of data management needs.« less

Maternal inflammation modulates infant immune response patterns to viral lung challenge in a murine model.

PubMed

Gleditsch, Dorothy D; Shornick, Laurie P; Van Steenwinckel, Juliette; Gressens, Pierre; Weisert, Ryan P; Koenig, Joyce M

2014-07-01

Chorioamnionitis, an inflammatory gestational disorder, commonly precedes preterm delivery. Preterm infants may be at particular risk for inflammation-related morbidity related to infection, although the pathogenic mechanisms are unclear. We hypothesized that maternal inflammation modulates immune programming to drive postnatal inflammatory processes. We used a novel combined murine model to treat late gestation dams with low-dose lipopolysaccharide (LPS) and to secondarily challenge exposed neonates or weanlings with Sendai virus (SeV) lung infection. Multiple organs were analyzed to characterize age-specific postnatal immune and inflammatory responses. Maternal LPS treatment enhanced innate immune populations in the lungs, livers, and/or spleens of exposed neonates or weanlings. Secondary lung SeV infection variably affected neutrophil, macrophage, and dendritic cell proportions in multiple organs of exposed pups. Neonatal lung infection induced brain interleukin (IL)-4 expression, although this response was muted in LPS-exposed pups. Adaptive immune cells, including lung, lymph node, and thymic lymphocytes and lung CD4 cells expressing FoxP3, interferon (IFN)-γ, or IL-17, were variably prominent in LPS-exposed pups. Maternal inflammation modifies postnatal immunity and augments systemic inflammatory responses to viral lung infection in an age-specific manner. We speculate that inflammatory modulation of the developing immune system contributes to chronic morbidity and mortality in preterm infants.

Effect of chromium on bioenergetics and leukocyte dynamics following immunoactivation in lactating Holstein cows.

PubMed

Horst, E A; Kvidera, S K; Mayorga, E J; Shouse, C S; Al-Qaisi, M; Dickson, M J; Ydstie, J; Ramirez Ramirez, H A; Keating, A F; Dickson, D J; Griswold, K E; Baumgard, L H

2018-06-01

Activated immune cells are insulin sensitive and utilize copious amounts of glucose. Because chromium (Cr) increases insulin sensitivity and may be immunomodulatory, our objective was to evaluate the effect of supplemental Cr (KemTrace Cr propionate, 20 g/d; Kemin Industries Inc., Des Moines, IA) on immune system glucose utilization and immune system dynamics following an intravenous endotoxin challenge in lactating Holstein cows. Twenty cows (320 ± 18 d in milk) were randomly assigned to 1 of 4 treatments: (1) pair-fed (PF) control (PF-CON; 5 mL of saline; n = 5), (2) PF and Cr supplemented (PF-Cr; 5 mL of saline; n = 5), (3) lipopolysaccharide (LPS)-euglycemic clamp and control supplemented (LPS-CON; 0.375 µg/kg of body weight LPS; n = 5), and (4) LPS-euglycemic clamp and Cr supplemented (LPS-Cr; 0.375 µg/kg of body weight LPS; n = 5). The experiment was conducted serially in 3 periods (P). During P1 (3 d), cows received their respective dietary treatments and baseline values were obtained. At the initiation of P2 (2 d), either a 12-h LPS-euglycemic clamp was conducted or cows were PF to their respective dietary counterparts. During P3 (3 d), cows consumed feed ad libitum and continued to receive their respective dietary treatment. During P2, LPS administration decreased dry matter intake (DMI; 40%) similarly among diets, and by experimental design the pattern and magnitude of reduced DMI were similar in the PF cohorts. During P3, LPS-Cr cows tended to have decreased DMI (6%) relative to LPS-CON cows. Relative to controls, milk yield from LPS-challenged cows decreased (58%) during P2 and LPS-Cr cows produced less (16%) milk than LPS-CON cows. During P3, milk yield progressively increased similarly in LPS-administered cows, but overall milk yield remained decreased (24%) compared with PF controls. There were no dietary treatment differences in milk yield during P3. Circulating insulin increased 9- and 15-fold in LPS-administered cows at 6 and 12 h postbolus, respectively, compared with PF controls. Compared with LPS-CON cows, circulating insulin in LPS-Cr cows was decreased (48%) at 6 h postbolus. Relative to PF cows, circulating LPS binding protein and serum amyloid A from LPS-administered cows increased 2- and 5-fold, respectively. Compared with PF cows, blood neutrophil counts in LPS-infused cows initially decreased, then gradually increased 163%. Between 18 and 48 h postbolus, the number of neutrophils was increased (12%) in LPS-Cr versus LPS-CON cows. The 12-h total glucose deficit was 220 and 1,777 g for the PF and LPS treatments, respectively, but glucose utilization following immune activation was not influenced by Cr. In summary, supplemental Cr reduced the insulin response and increased circulating neutrophils following an LPS challenge but did not appear to alter the immune system's glucose requirement following acute and intense activation. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Age-associated metabolic dysregulation in bone marrow-derived macrophages stimulated with lipopolysaccharide

NASA Astrophysics Data System (ADS)

Fei, Fan; Lee, Keith M.; McCarry, Brian E.; Bowdish, Dawn M. E.

2016-03-01

Macrophages are major contributors to age-associated inflammation. Metabolic processes such as oxidative phosphorylation, glycolysis and the urea cycle regulate inflammatory responses by macrophages. Metabolic profiles changes with age; therefore, we hypothesized that dysregulation of metabolic processes could contribute to macrophage hyporesponsiveness to LPS. We examined the intracellular metabolome of bone marrow-derived macrophages from young (6-8 wk) and old (18-22 mo) mice following lipopolysaccharide (LPS) stimulation and tolerance. We discovered known and novel metabolites that were associated with the LPS response of macrophages from young mice, which were not inducible in macrophages from old mice. Macrophages from old mice were largely non-responsive towards LPS stimulation, and we did not observe a shift from oxidative phosphorylation to glycolysis. The critical regulatory metabolites succinate, γ-aminobutyric acid, arginine, ornithine and adenosine were increased in LPS-stimulated macrophages from young mice, but not macrophages from old mice. A shift between glycolysis and oxidative phosphorylation was not observed during LPS tolerance in macrophages from either young or old mice. Metabolic bottlenecks may be one of the mechanisms that contribute to the dysregulation of LPS responses with age.

ILK mediates LPS-induced vascular adhesion receptor expression and subsequent leucocyte trans-endothelial migration.

PubMed

Hortelano, Sonsoles; López-Fontal, Raquel; Través, Paqui G; Villa, Natividad; Grashoff, Carsten; Boscá, Lisardo; Luque, Alfonso

2010-05-01

The inflammatory response to injurious agents is tightly regulated to avoid adverse consequences of inappropriate leucocyte accumulation or failed resolution. Lipopolysaccharide (LPS)-activated endothelium recruits leucocytes to the inflamed tissue through controlled expression of membrane-associated adhesion molecules. LPS responses in macrophages are known to be regulated by integrin-linked kinase (ILK); in this study, we investigated the role of ILK in the regulation of the LPS-elicited inflammatory response in endothelium. This study was performed on immortalized mouse endothelial cells (EC) isolated from lung and coronary vasculature. Cells were thoroughly characterized and the role of ILK in the regulation of the LPS response was investigated by suppressing ILK expression using siRNA and shRNA technologies. Phenotypic and functional analyses confirmed that the immortalized cells behaved as true EC. LPS induced the expression of the inflammatory genes E-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). ILK knockdown impaired LPS-mediated endothelial activation by preventing the induction of ICAM-1 and VCAM-1. Blockade of the LPS-induced response inhibited the inflammatory-related processes of firm adhesion and trans-endothelial migration of leucocytes. ILK is involved in the expression of cell adhesion molecules by EC activated with the inflammatory stimulus LPS. This reduced expression modulates leucocyte adhesion to the endothelium and the extravasation process. This finding suggests ILK as a potential anti-inflammatory target for the development of vascular-specific treatments for inflammation-related diseases.

Lipopolysaccharide Membrane Building and Simulation

PubMed Central

Jo, Sunhwan; Wu, Emilia L.; Stuhlsatz, Danielle; Klauda, Jeffery B.; Widmalm, Göran; Im, Wonpil

2015-01-01

Summary While membrane simulations are widely employed to study the structure and dynamics of various lipid bilayers and membrane proteins in the bilayers, simulations of lipopolysaccharides (LPS) in membrane environments have been limited due to its structural complexity, difficulties in building LPS-membrane systems, and lack of appropriate molecular force field. In this work, as a first step to extend CHARMM-GUI Membrane Builder to incorporate LPS molecules and to explore their structures and dynamics in membrane environments using molecular dynamics simulations, we describe step-by-step procedures to build LPS bilayer systems using CHARMM and the recently developed CHARMM carbohydrate and lipid force fields. Such procedures are illustrated by building various bilayers of Escherichia coli O6 LPS and their preliminary simulation results are given in terms of per-LPS area and density distributions of various components along the membrane normal. PMID:25753722

Repulsive guidance molecule a blockade exerts the immunoregulatory function in DCs stimulated with ABP and LPS

PubMed Central

Xu, Xuxu; Gao, Yan; Zhai, Zhiyong; Zhang, Shuo; Shan, Fengping; Feng, Juan

2016-01-01

ABSTRACT Repulsive guidance molecule a (RGMa) is an axonal guidance molecule that has recently found to exert function in immune system. This study evaluated the function of RGMa in modulation of dendritic cells (DCs) function stimulated with Achyranthes bidentata polysaccharide (ABP) and lipopolysaccharide (LPS) using a RGMa-neutralizing antibody. Compared with the Control-IgG/ABP and Control-IgG/LPS groups, DCs in the Anti-RGMa/ABP and Anti-RGMa/LPS groups 1) showed small, round cells with a few cell processes and organelles, and many pinocytotic vesicles; 2) had decreased MHC II, CD86, CD80, and CD40 expression; 3) displayed the decreased IL-12p70, IL-1β and TNF-α levels and increased IL-10 secretion; 4) had a high percentage of FITC-dextran uptake; and 5) displayed a reduced ability to drive T cell proliferation and reinforced T cell polarization toward a Th2 cytokine pattern. We conclude that DCs treated with RGMa-neutralizing antibodies present with tolerogenic and immunoregulatory characteristics, which provides new insights into further understanding of the function of RGMa. PMID:26986456

Repulsive guidance molecule a blockade exerts the immunoregulatory function in DCs stimulated with ABP and LPS.

PubMed

Xu, Xuxu; Gao, Yan; Zhai, Zhiyong; Zhang, Shuo; Shan, Fengping; Feng, Juan

2016-08-02

Repulsive guidance molecule a (RGMa) is an axonal guidance molecule that has recently found to exert function in immune system. This study evaluated the function of RGMa in modulation of dendritic cells (DCs) function stimulated with Achyranthes bidentata polysaccharide (ABP) and lipopolysaccharide (LPS) using a RGMa-neutralizing antibody. Compared with the Control-IgG/ABP and Control-IgG/LPS groups, DCs in the Anti-RGMa/ABP and Anti-RGMa/LPS groups 1) showed small, round cells with a few cell processes and organelles, and many pinocytotic vesicles; 2) had decreased MHC II, CD86, CD80, and CD40 expression; 3) displayed the decreased IL-12p70, IL-1β and TNF-α levels and increased IL-10 secretion; 4) had a high percentage of FITC-dextran uptake; and 5) displayed a reduced ability to drive T cell proliferation and reinforced T cell polarization toward a Th2 cytokine pattern. We conclude that DCs treated with RGMa-neutralizing antibodies present with tolerogenic and immunoregulatory characteristics, which provides new insights into further understanding of the function of RGMa.

Candesartan ameliorates impaired fear extinction induced by innate immune activation.

PubMed

Quiñones, María M; Maldonado, Lizette; Velazquez, Bethzaly; Porter, James T

2016-02-01

Patients with post-traumatic stress disorder (PTSD) tend to show signs of a relatively increased inflammatory state suggesting that activation of the immune system may contribute to the development of PTSD. In the present study, we tested whether activation of the innate immune system can disrupt acquisition or recall of auditory fear extinction using an animal model of PTSD. Male adolescent rats received auditory fear conditioning in context A. The next day, an intraperitoneal injection of lipopolysaccharide (LPS; 100 μg/kg) prior to auditory fear extinction in context B impaired acquisition and recall of extinction. LPS (100 μg/kg) given after extinction training did not impair extinction recall suggesting that LPS did not affect consolidation of extinction. In contrast to cued fear extinction, contextual fear extinction was not affected by prior injection of LPS (100 μg/kg). Although LPS also reduced locomotion, we could dissociate the effects of LPS on extinction and locomotion by using a lower dose of LPS (50 μg/kg) which impaired locomotion without affecting extinction. In addition, 15 h after an injection of 250 μg/kg LPS in adult rats, extinction learning and recall were impaired without affecting locomotion. A sub-chronic treatment with candesartan, an angiotensin II type 1 receptor blocker, prevented the LPS-induced impairment of extinction in adult rats. Our results demonstrate that activation of the innate immune system can disrupt auditory fear extinction in adolescent and adult animals. These findings also provide direction for clinical studies of novel treatments that modulate the innate immune system for stress-related disorders like PTSD. Copyright © 2015 Elsevier Inc. All rights reserved.

Moderate glucose supply reduces hemolysis during systemic inflammation

PubMed Central

Jägers, Johannes; Brauckmann, Stephan; Kirsch, Michael; Effenberger-Neidnicht, Katharina

2018-01-01

Background Systemic inflammation alters energy metabolism. A sufficient glucose level, however, is most important for erythrocytes, since erythrocytes rely on glucose as sole source of energy. Damage to erythrocytes leads to hemolysis. Both disorders of glucose metabolism and hemolysis are associated with an increased risk of death. The objective of the study was to investigate the impact of intravenous glucose on hemolysis during systemic inflammation. Materials and methods Systemic inflammation was accomplished in male Wistar rats by continuous lipopolysaccharide (LPS) infusion (1 mg LPS/kg and h, 300 min). Sham control group rats received Ringer’s solution. Glucose was supplied moderately (70 mg glucose/kg and h) or excessively (210 mg glucose/kg and h) during systemic inflammation. Vital parameters (eg, systemic blood pressure) as well as blood and plasma parameters (eg, concentrations of glucose, lactate and cell-free hemoglobin, and activity of lactate dehydrogenase) were measured hourly. Clot formation was analyzed by thromboelastometry. Results Continuous infusion of LPS led to a so-called post-aggression syndrome with disturbed electrolyte homeostasis (hypocalcemia, hyperkalemia, and hypernatremia), changes in hemodynamics (tachycardia and hypertension), and a catabolic metabolism (early hyperglycemia, late hypoglycemia, and lactate formation). It induced severe tissue injury (significant increases in plasma concentrations of transaminases and lactate dehydrogenase), alterations in blood coagulation (disturbed clot formation), and massive hemolysis. Both moderate and excessive glucose supply reduced LPS-induced increase in systemic blood pressure. Excessive but not moderate glucose supply increased blood glucose level and enhanced tissue injury. Glucose supply did not reduce LPS-induced alterations in coagulation, but significantly reduced hemolysis induced by LPS. Conclusion Intravenous glucose infusion can diminish LPS-related changes in hemodynamics, glucose metabolism, and, more interestingly, LPS-induced hemolysis. Since cell-free hemoglobin is known to be a predictor for patient’s survival, a reduction of hemolysis by 35% only by the addition of a small amount of glucose is another step to minimize mortality during systemic inflammation. PMID:29559805

Potential role of punicalagin against oxidative stress induced testicular damage.

PubMed

Rao, Faiza; Tian, Hui; Li, Wenqing; Hung, Helong; Sun, Fei

2016-01-01

Punicalagin is isolated from pomegranate and widely used for the treatment of different diseases in Chinese traditional medicine. This study aimed to evaluate the effect of Punicalagin (purity ≥98%) on oxidative stress induced testicular damage and its effect on fertility. We detected the antioxidant potential of punicalagin in lipopolysaccharide (LPS) induced oxidative stress damage in testes, also tried to uncover the boosting fertility effect of Punicalagin (PU) against oxidative stress-induced infertility. Results demonstrated that 9 mg kg-1 for 7 days treatment significantly decreases LPS induced oxidative damage in testes and nitric oxide production. The administration of oxidative stress resulted in a significant reduction in testes antioxidants GSH, T-SOD, and CAT raised LPO, but treatment with punicalagin for 7 days increased antioxidant defense GSH, T-SOD, and CAT by the end of the experiment and reduced LPO level as well. PU also significantly activates Nrf2, which is involved in regulation of antioxidant defense systems. Hence, the present research categorically elucidates the protective effect of punicalagin against LPS induced oxidative stress induced perturbation in the process of spermatogenesis and significantly increased sperm health and number. Moreover, fertility success significantly decreased in LPS-injected mice compared to controls. Mice injected with LPS had fertility indices of 12.5%, while others treated with a combination of PU + LPS exhibited 75% indices. By promoting fertility and eliminating oxidative stress and inflammation, PU may be a useful nutrient for the treatment of infertility.

Potential role of punicalagin against oxidative stress induced testicular damage

PubMed Central

Rao, Faiza; Tian, Hui; Li, Wenqing; Hung, Helong; Sun, Fei

2016-01-01

Punicalagin is isolated from pomegranate and widely used for the treatment of different diseases in Chinese traditional medicine. This study aimed to evaluate the effect of Punicalagin (purity ≥98%) on oxidative stress induced testicular damage and its effect on fertility. We detected the antioxidant potential of punicalagin in lipopolysaccharide (LPS) induced oxidative stress damage in testes, also tried to uncover the boosting fertility effect of Punicalagin (PU) against oxidative stress-induced infertility. Results demonstrated that 9 mg kg−1 for 7 days treatment significantly decreases LPS induced oxidative damage in testes and nitric oxide production. The administration of oxidative stress resulted in a significant reduction in testes antioxidants GSH, T-SOD, and CAT raised LPO, but treatment with punicalagin for 7 days increased antioxidant defense GSH, T-SOD, and CAT by the end of the experiment and reduced LPO level as well. PU also significantly activates Nrf2, which is involved in regulation of antioxidant defense systems. Hence, the present research categorically elucidates the protective effect of punicalagin against LPS induced oxidative stress induced perturbation in the process of spermatogenesis and significantly increased sperm health and number. Moreover, fertility success significantly decreased in LPS-injected mice compared to controls. Mice injected with LPS had fertility indices of 12.5%, while others treated with a combination of PU + LPS exhibited 75% indices. By promoting fertility and eliminating oxidative stress and inflammation, PU may be a useful nutrient for the treatment of infertility. PMID:26763544

Dynamic movement of cytochrome c from mitochondria into cytosol and peripheral circulation in massive hepatic cell injury.

PubMed

Kobayashi, Yoshinori; Mori, Masaaki; Naruto, Takuya; Kobayashi, Naoki; Sugai, Toshiyuki; Imagawa, Tomoyuki; Yokota, Shumpei

2004-12-01

In the process of apoptosis, it is known that the transition of cytochrome c from mitochondria into the cytosol occurs, and tumor necrosis factor (TNF)-alpha is one of the molecules responsible for this event. But in the state of hypercytokine induced by D-galactosamine (D-GaIN)/Lipopolysaccharide (LPS), the localization of cytochrome c is little known. Rats were administrated with D-GaIN(700 mg/kg)/LPS(200 microg/kg). Blood and tissue samples were collected and examined for levels of pro-inflammatory cytokines, the apoptosis of liver cells, and the localization of cytochrome c. Before administration of D-GaIN/LPS, cytochrome c was definitely localized in the mitochondria. At 2 h after simultaneous administration of D-GaIN/LPS, cytochrome c had accumulated in the cytosol following abrupt increases of plasma TNF-alpha. Massive cell destruction due to apoptosis proved by Terminal deoxynucleo-tidyl transferase-mediated dUTP nick end labeling staining was observed in liver tissue 4 h later and markedly increased levels of cytochrome c were detected in the plasma 12 h after D-GaIN/LPS administration. Liver injury induced by simultaneous administration of D-GaIN/LPS was closely associated with the production of TNF-alpha, and also with the dynamic movement of cytochrome c from the mitochondria into the cytosol, and then into the systemic circulation. The detection of plasma cytochrome c levels may be a useful clinical tool for the detection of apoptosis in vivo.

Dysregulated expression of miR-101b and miR-26b lead to age-associated increase in LPS-induced COX-2 expression in murine macrophage.

PubMed

Liu, Dan; Wang, Dongsheng; Xu, Zhenbiao; Gao, Jing; Liu, Min; Liu, Yanxin; Jiang, Minghong; Zheng, Dexian

2015-10-01

Aging is the natural process of decline in physiological structure and function of various molecules, cells, tissues, and organs. Growing evidence indicates that increased immune genetic diversity and dysfunction of immune system cause aging-related pathophysiological process with the growth of age. In the present study, we observed that LPS-induced higher activation of cyclooxygenase (COX)-2 promoter is associated with the upregulated binding activity of nuclear factor kappa B (NF-κB) in peritoneal macrophages of aged mice than young ones. Additionally, COX-2 is a direct target of miR-101b and miR-26b in the macrophages. Significant upregulation of miR-101b and miR-26b effectively prevented LPS-induced excessive expression of COX-2 in the young mice. Because these negative regulatory factors were unresponsive to LPS stimulation, the levels of COX-2 were markedly higher in the macrophages of aged mice. Further study showed that NF-κB activation contributed to the increase in the expression of miR-101b and miR-26b in the LPS-stimulated macrophages of young mice, but not aged ones. Moreover, histone deacetylase (HDAC) inhibitor trichostatin A (TSA) upregulated expression of miR-101b and miR-26b in the aged mouse macrophages only, but not the young cells. This demonstrated that HDAC suppressed the expression of miR-101b and miR-26b in the LPS-treated macrophages of aged mice and contributed to the aging process. TSA-induced increased expression of miR-101b and miR-26b could further suppress COX-2 expression. These findings provide novel evidence on the regulation of immune senescence and miR-101b and miR-26b, which might be promising targets in treating aged-related inflammatory diseases. Epigenetic regulation of the microRNAs (miRNAs) provides an important evidence for the treatment of innate inflammatory disease with HDAC inhibitors in elderly.

Role of poly-(ADP-ribose) synthetase in lipopolysaccharide-induced vascular failure and acute lung injury in pigs.

PubMed

Albertini, M; Clement, M G; Lafortuna, C L; Caniatti, M; Magder, S; Abdulmalek, K; Hussain, S N

2000-06-01

To assess the contribution of poly (adenosine 5'-diphosphate ribose) synthetase (PARS) to the development of bacterial lipopolysaccharide (LPS)-induced acute lung injury and vascular failure in pigs. Four groups of anesthetized, paralyzed, and mechanically ventilated domestic white pigs. Group 1 served as control, whereas Escherichia coli LPS (20 microg/kg/h) was continuously infused in group 2. Group 3 received 20 mg/kg injection of 3-aminobenzamide (a selective inhibitor of PARS activity) 15 minutes before LPS infusion. Only 3-aminobenzamide and not LPS was injected in group 4. All animals were examined for 180 minutes. Systemic and pulmonary hemodynamics and lung mechanics were measured during the experimental period. Lung wet/dry ratio, bronchoalveolar lavage (BAL) protein levels and cell counts and lung nitrotyrosine (footprint of peroxynitrite) immunostaining were also measured in a few animals. LPS infusion evoked a progressive decline in systemic arterial pressure, a small increase in cardiac output, and biphasic elevation of pulmonary arterial pressure. Lung compliance declined progressively, whereas lung and total respiratory resistance rose significantly after LPS infusion. Prominent nitrotyrosine immunostaining was detected around small airways and pulmonary endothelium of LPS-infused animals. No significant changes in lung wet/dry ratio and BAL protein levels and cell counts were produced by LPS infusion. Pretreatment with 3-aminobenzamide did not alter the systemic and pulmonary hemodynamic responses to LPS infusion but eliminated the rise in pulmonary and total respiratory resistance. We concluded that PARS activation plays an important role in the changes of lung mechanics associated with LPS-induced acute lung injury but had no role in vascular failure.

From Theory to Data: The Process of Refining Learning Progressions

ERIC Educational Resources Information Center

Shea, Nicole A.; Duncan, Ravit Golan

2013-01-01

Learning progressions (LPs) are theoretical models of how learners develop expertise in a domain over extended periods of time. Recent policy reports have touted LPs as a promising approach to aligning standards, curriculum, and assessment. However, the scholarship on LPs is relatively sparse, and the jury is still out on the theoretical and…

Estimating glucose requirements of an activated immune system in growing pigs.

PubMed

Kvidera, S K; Horst, E A; Mayorga, E J; Sanz-Fernandez, M V; Abuajamieh, M; Baumgard, L H

2017-11-01

Activated immune cells become obligate glucose utilizers, and a large i.v. lipopolysaccharide (LPS) dose causes insulin resistance and severe hypoglycemia. Therefore, study objectives were to quantify the amount of glucose needed to maintain euglycemia following an endotoxin challenge as a proxy of leukocyte glucose requirements. Fifteen fasted crossbred gilts (30.3 ± 1.7 kg) were bilaterally jugular catheterized and assigned 1 of 2 i.v. bolus treatments: control (CON; 10 mL sterile saline; = 7) or LPS challenge + euglycemic clamp (LPS-Eu; 055:B5; 5 μg/kg BW; 50% dextrose infusion to maintain euglycemia; = 8). Following administration, blood glucose was determined every 10 min and dextrose infusion rates were adjusted in LPS-Eu pigs to maintain euglycemia for 8 h. Pigs were fasted for 8 h prior to the bolus and remained fasted throughout the challenge. Rectal temperature was increased in LPS-Eu pigs relative to CON pigs (39.8 vs. 38.8°C; < 0.01). Relative to the baseline, CON pigs had 20% decreased blood glucose from 300 to 480 min postbolus ( = 0.01) whereas circulating glucose content in LPS-Eu pigs did not differ ( = 0.96) from prebolus levels. A total of 116 ± 8 g of infused glucose was required to maintain euglycemia in LPS-Eu pigs. Relative to CON pigs, overall plasma insulin, blood urea nitrogen, β-hydroxybutrate, lactate, and LPS-binding protein were increased in LPS-Eu pigs (295, 108, 29, 133, and 13%, respectively; ≤ 0.04) whereas NEFA was decreased (66%; < 0.01). Neutrophils in LPS-Eu pigs were decreased 84% at 120 min postbolus and returned to CON levels by 480 min ( < 0.01). Overall, lymphocytes, monocytes, eosinophils, and basophils were decreased in LPS-Eu pigs relative to CON pigs (75, 87, 70, and 50%, respectively; ≤ 0.05). These alterations in metabolism and the large amount of glucose needed to maintain euglycemia indicate nutrient repartitioning away from growth toward the immune system. Glucose is an important fuel for the immune system, and data from this study established that the glucose requirements of an intensely and acutely activated immune system in growing pigs are approximately 1.1 g/kg BW/h.

Whey protein hydrolysates decrease IL-8 secretion in lipopolysaccharide (LPS)-stimulated respiratory epithelial cells by affecting LPS binding to Toll-like receptor 4.

PubMed

Iskandar, Michèle M; Dauletbaev, Nurlan; Kubow, Stan; Mawji, Nadir; Lands, Larry C

2013-07-14

Whey proteins (WP) exert anti-inflammatory and antioxidant effects. Hyperbaric pressurisation of whey increases its digestibility and changes the spectrum of peptides released during digestion. We have shown that dietary supplementation with pressurised whey improves nutritional status and systemic inflammation in patients with cystic fibrosis (CF). Both clinical indices are largely affected by airway processes, to which respiratory epithelial cells actively contribute. Here, we tested whether peptides released from the digestion of pressurised whey can attenuate the inflammatory responses of CF respiratory epithelial cells. Hydrolysates of pressurised WP (pWP) and native WP (nWP, control) were generated in vitro and tested for anti-inflammatory properties judged by the suppression of IL-8 production in CF and non-CF respiratory epithelial cell lines (CFTE29o- and 1HAEo-, respectively). We observed that, in both cell lines, pWP hydrolysate suppressed IL-8 production stimulated by lipopolysaccharide (LPS) to a greater magnitude compared with nWP hydrolysate. Neither hydrolysate suppressed IL-8 production induced by TNF-α or IL-1β, suggesting an effect on the Toll-like receptor (TLR) 4 pathway, the cellular sensor for LPS. Further, neither hydrolysate affected TLR4 expression or neutralised LPS. Both pWP and nWP hydrolysates similarly reduced LPS binding to surface TLR4, while pWP tended to more potently increase extracellular antioxidant capacity. (1) anti-inflammatory properties of whey are enhanced by pressurisation; (2) suppression of IL-8 production may contribute to the clinical effects of pressurised whey supplementation on CF; (3) this effect may be partly explained by a combination of reduced LPS binding to TLR4 and enhanced extracellular antioxidant capacity.

Protective effects of agmatine on lipopolysaccharide-injured microglia and inducible nitric oxide synthase activity.

PubMed

Ahn, Soo Kyung; Hong, Samin; Park, Yu Mi; Choi, Ja Yong; Lee, Won Taek; Park, Kyung Ah; Lee, Jong Eun

2012-12-17

Proinflammatory factors released from activated microglia contribute to maintaining homeostasis against various noxious stimuli in the central nervous system. If excessive, however, they may initiate a pathologic neuroinflammatory process. In this investigation, we evaluated whether agmatine, a primary polyamine known to protect neurons, reduces lipopolysaccharide (LPS)-induced damage to microglia in vitro and in vivo. For in vitro study, BV2-immortalized murine microglia were exposed to LPS with agmatine treatment. After 24hours, cell viability and the amount of nitrite generated were determined. For in vivo study, LPS was microinjected into the corpus callosum of adult male albino mice. Agmatine was intraperitoneally administered at the time of injury. Brains were evaluated 24hours after LPS microinjection to check for immunoreactivity with a microglial marker of ionized calcium binding adaptor molecule 1 (Iba1) and inducible nitric oxide synthase (iNOS). Using western blot analysis, protein expression of iNOS as well as that of the proinflammatory cytokines, tumor necrosis factor (TNF)-α and interleukin (IL)-1β, was determined. Agmatine significantly reduced the LPS-induced BV2 microglial cytotoxicity from over 80% to less than 60% (p<0.001), as determined by lactate dehydrogenase assay. It suppressed the nitrite production from 16.4±3.14μM to 5.5±1.27μM (p<0.001), as measured using the Griess reaction. Agmatine also decreased the activities of microglia and iNOS induced by LPS microinjection into corpus callosum. Our findings reveal that agmatine attenuates LPS-induced microglial damage and suggest that agmatine may serve as a novel therapeutic strategy for neuroinflammatory diseases. Copyright © 2012 Elsevier Inc. All rights reserved.

Mass spectrometry based structural analysis and systems immunoproteomics strategies for deciphering the host response to endotoxin.

PubMed

Khan, Mohd M; Ernst, Orna; Sun, Jing; Fraser, Iain D C; Ernst, Robert K; Goodlett, David R; Nita-Lazar, Aleksandra

2018-06-24

One cause of sepsis is systemic maladaptive immune response of the host to bacteria and specifically, to Gram-negative bacterial outer membrane glycolipid lipopolysaccharide (LPS). On the host myeloid cell surface, proinflammatory LPS activates the innate immune system via Toll-like receptor-4 (TLR4)/myeloid differentiation factor-2 (MD2) complex. Intracellularly, LPS is also sensed by the noncanonical inflammasome through caspase-11 in mice and 4/5 in humans. The minimal functional determinant for innate immune activation is the membrane anchor of LPS called lipid A. Even subtle modifications to the lipid A scaffold can enable, diminish, or abolish immune activation. Bacteria are known to modify their LPS structure during environmental stress, and infection of hosts to alter cellular immune phenotypes. In this review, we describe how mass spectrometry (MS)-based structural analysis of endotoxin helped uncover major determinations of molecular pathogenesis. Through characterization of LPS modifications, we now better understand resistance to antibiotics and cationic antimicrobial peptides, as well as how the environment impacts overall endotoxin structure. In addition, MS-based systems immunoproteomics approaches can assist in elucidating the immune response against LPS. Many regulatory proteins have been characterized through proteomics and global/targeted analysis of protein modifications, enabling the discovery and characterization of novel endotoxin-mediated protein translational modifications (PTMs). Copyright © 2018. Published by Elsevier Ltd.

Summary of 2011 Direct and Nearby Lightning Strikes to Launch Complex 39B, Kennedy Space Center, Florida

NASA Technical Reports Server (NTRS)

Mata, C.T.; Mata, A.G.

2012-01-01

A Lightning Protection System (LPS) was designed and built at Launch Complex 39B (LC39B), at the Kennedy Space Center (KSC), Florida in 2009. This LPS was instrumented with comprehensive meteorological and lightning data acquisition systems that were deployed from late 2010 until mid 2011. The first direct strikes to the LPS were recorded in March of 2011, when a limited number of sensors had been activated. The lightning instrumentation system detected a total of 70 nearby strokes and 19 direct strokes to the LPS, 2 of the 19 direct strokes to the LPS had two simultaneous ground attachment points (in both instances one channel terminated on the LPS and the other on the nearby ground). Additionally, there are more unaccounted nearby strokes seen on video records for which limited data was acquired either due to the distance of the stroke or the settings of the data acquisition system. Instrumentation deployment chronological milestones, a summary of lightning strikes (direct and nearby), high speed video frames, downconductor currents, and dH/dt and dE/dt typical waveforms for direct and nearby strokes are presented.

Relationship between luminous fish and symbiosis. I. Comparative studies of lipopolysaccharides isolated from symbiotic luminous bacteria of the luminous marine fish, Physiculus japonicus.

PubMed

Kuwae, T; Andoh, M; Fukasawa, S; Kurata, M

1983-01-01

In order to investigate the relationship between host and symbiosis in the luminous marine fish, Physiculus japonicus, the bacterial lipopolysaccharides (LPS) of symbiotic luminous bacteria were compared serologically and electrophoretically. Five symbiotic luminous bacteria (PJ strains) were separately isolated from five individuals of this fish species caught at three points, off the coasts of Chiba, Nakaminato, and Oharai. LPS preparations were made from these bacteria by Westphal's phenol-water method and highly purified by repeated ultracentrifugation. These LPSs contained little or no 2-keto-3-deoxyoctonate and had powerful mitogenic activity. In sodium dodecylsulfate polyacrylamide gel electrophoresis, these PJ-1 to -5 LPSs were separated by their electrophoretic patterns into three groups; the first group included PJ-1 and PJ-4, the second group PJ-2 and PJ-3, and the third group PJ-5 alone. The results agreed with those of the double immunodiffusion test; precipitin lines completely coalesced within each group but not with other groups. In immunoelectrophoresis, one precipitin line was observed between anti PJ-2 LPS serum and PJ-5 LPS but the electrophoretic mobility of PJ-5 LPS was clearly different from that of the PJ-2 LPS group. Furthermore, in a 50% inhibition test with PJ-2 LPS by the passive hemolysis system, the doses of PJ-2 LPS, PJ-3 LPS, and PJ-5 LPS required for 50% inhibition (ID50) in this system were 0.25, 0.25, and 21.6 micrograms/ml for each alkali-treated LPS, respectively, and the ID50's of both PJ-1 LPS and PJ-4 LPS were above 1,000 micrograms/ml. These results indicate that PJ-5 LPS has an antigenic determinant partially in common with LPS from the PJ-2 group but not with LPS from the PJ-1 group and that the symbiotic luminous bacterium PJ-5 is more closely related to the PJ-2 group than to the PJ-1 group. These results show that the species Physiculus japonicus is symbiotically associated with at least three immunologically different strains of luminous marine bacteria in its specialized light organ.

Visualization and analysis of lipopolysaccharide distribution in binary phospholipid bilayers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henning, Maria Florencia; Sanchez, Susana; Bakas, Laura, E-mail: lbakas@biol.unlp.edu.ar

2009-05-22

Lipopolysaccharide (LPS) is an endotoxin released from the outer membrane of Gram-negative bacteria during infections. It have been reported that LPS may play a role in the outer membrane of bacteria similar to that of cholesterol in eukaryotic plasma membranes. In this article we compare the effect of introducing LPS or cholesterol in liposomes made of dipalmitoylphosphatidylcholine/dioleoylphosphatidylcholine on the solubilization process by Triton X-100. The results show that liposomes containing LPS or cholesterol are more resistant to solubilization by Triton X-100 than the binary phospholipid mixtures at 4 {sup o}C. The LPS distribution was analyzed on GUVs of DPPC:DOPC usingmore » FITC-LPS. Solid and liquid-crystalline domains were visualized labeling the GUVs with LAURDAN and GP images were acquired using a two-photon microscope. The images show a selective distribution of LPS in gel domains. Our results support the hypothesis that LPS could aggregate and concentrate selectively in biological membranes providing a mechanism to bring together several components of the LPS-sensing machinery.« less

Semi-Automatic Determination of Rockfall Trajectories

PubMed Central

Volkwein, Axel; Klette, Johannes

2014-01-01

In determining rockfall trajectories in the field, it is essential to calibrate and validate rockfall simulation software. This contribution presents an in situ device and a complementary Local Positioning System (LPS) that allow the determination of parts of the trajectory. An assembly of sensors (herein called rockfall sensor) is installed in the falling block recording the 3D accelerations and rotational velocities. The LPS automatically calculates the position of the block along the slope over time based on Wi-Fi signals emitted from the rockfall sensor. The velocity of the block over time is determined through post-processing. The setup of the rockfall sensor is presented followed by proposed calibration and validation procedures. The performance of the LPS is evaluated by means of different experiments. The results allow for a quality analysis of both the obtained field data and the usability of the rockfall sensor for future/further applications in the field. PMID:25268916

The interaction of lipopolysaccharide-coated polystyrene particle with membrane receptor proteins on macrophage measured by optical tweezers

NASA Astrophysics Data System (ADS)

Wei, Ming-Tzo; Hua, Kuo-Feng; Hsu, Jowey; Karmenyan, Artashes; Hsu, Hsien-Yeh; Chiou, Arthur

2006-08-01

Lipopolysaccharide (LPS) is one of the cell wall components of Gram-positive bacteria recognized by and interacted with receptor proteins such as CD14 on macrophage cells. Such a process plays an important role in our innate immune system. In this paper, we report the application of optical tweezers (λ = 1064nm Gaussian beam focused by a water-immersed objective lens with N.A. = 1.0) to the study of the dynamics of the binding of a LPS-coated polystyrene particle (diameter = 1.5μm) onto the plasma membrane of a macrophage cell. We demonstrated that the binding rate increased significantly when the macrophage cell was pre-treated with the extract of Reishi polysaccharides (EORP) which has been shown to enhance the cell surface expression of CD14 (receptor of LPS) on macrophage cells.

Lipopolysaccharide mitagates methamphetamine-induced striatal dopamine depletion via modulating local TNF-alpha and dopamine transporter expression.

PubMed

Lai, Yu-Ting; Tsai, Yen-Ping N; Cherng, Chianfang G; Ke, Jing-Jer; Ho, Ming-Che; Tsai, Chia-Wen; Yu, Lung

2009-04-01

Systemic lipopolysaccharide (LPS) treatment may affect methamphetamine (MA)-induced nigrostriatal dopamine (DA) depletion. This study was undertaken to determine the critical time window for the protective effects of LPS treatment and the underlying mechanisms. An LPS injection (1 mg/kg) 72 h before or 2 h after MA treatment [three consecutive, subcutaneous injections of MA (10 mg/kg each) at 2-h intervals] diminished the MA-induced DA depletion in mouse striatum. Such an LPS-associated effect was independent of MA-produced hyperthermia. TNF-alpha, IL-1beta, IL-6 expressions were all elevated in striatal tissues following a systemic injection with LPS, indicating that peripheral LPS treatment affected striatal pro-inflammatory cytokine expression. Striatal TNF-alpha expression was dramatically increased at 72 and 96 h after the MA treatment, while such TNF-alpha elevation was abolished by the LPS pretreatment protocol. Moreover, MA-produced activation of nuclear NFkappaB, a transcription factor following TNF-alpha activation, in striatum was abolished by the LPS (1 mg/kg) pretreatment. Furthermore, thalidomide, a TNF-alpha antagonist, treatment abolished the LPS pretreatment-associated protective effects. Pretreatment with mouse recombinant TNF-alpha in striatum diminished the MA-produced DA depletion. Finally, single LPS treatment caused a rapid down-regulation of dopamine transporter (DAT) in striatum. Taken together, we conclude that peripheral LPS treatment protects nigrostriatal DA neurons against MA-induced toxicity, in part, by reversing elevated TNF-alpha expression and subsequent signaling cascade and causing a rapid DAT down-regulation in striatum.

Immunization of cows with novel core glycolipid vaccine induces anti-endotoxin antibodies in bovine colostrum.

PubMed

Cross, Alan S; Karreman, Hubert J; Zhang, Lei; Rosenberg, Zeil; Opal, Steven M; Lees, Andrew

2014-10-21

Translocation of gut-derived Gram-negative bacterial (GNB) lipopolysaccharide (LPS, or endotoxin) is a source of systemic inflammation that exacerbates HIV, cardiovascular and gastrointestinal diseases and malnutrition. The oral administration of bovine colostrum (BC) reduces endotoxemia in patients with impaired gut barrier function. Consequently, BC enriched in antibodies to LPS may ameliorate endotoxemia-related morbidities. We developed a detoxified J5 LPS/group B meningococcal outer membrane protein (J5dLPS/OMP) vaccine that induces antibodies against a highly conserved core region of LPS and protects against heterologous GNB infection. We now examine the ability of this vaccine to elicit anti-core endotoxin antibodies in BC. Two cohorts of pregnant cows were immunized with this vaccine in combination with FICA (Cohort 1) or Emulsigen-D (Cohort 2) adjuvants. Antibody responses to the J5 core LPS antigen were measured in both serum and colostrum and compared to antibody levels elicited by a commercially available veterinary vaccine (J5 Bacterin) comprised of heat-killed Escherichia coli O111, J5 mutant bacteria, from which the J5 LPS was purified. The J5dLPS/OMP vaccine induced high titers of serum IgG antibody to J5 LPS in all seven cows. Both IgG and to a lesser extent IgA anti-J5 LPS antibodies were generated in the colostrum. The J5dLPS/OMP vaccine was significantly more immunogenic in mice than was the J5 Bacterin. BC enriched in anti-J5 LPS antibody reduced circulating endotoxin levels in neutropenic rats, a model of "leaky gut". The J5dLPS/OMP vaccine elicits high titers of serum anti-endotoxin antibodies in cows that is passed to the colostrum. This BC enriched in anti-core LPS antibodies has the potential to reduce endotoxemia and ameliorate endotoxin-related systemic inflammation in patients with impaired gut barrier function. Since this vaccine is significantly more immunogenic than the J5 Bacterin vaccine, this J5dLPS/OMP vaccine might prove to be more useful for veterinary indications as well. Copyright © 2014 Elsevier Ltd. All rights reserved.

Anthocyanins control neuroinflammation and consequent memory dysfunction in mice exposed to lipopolysaccharide.

PubMed

Carvalho, Fabiano B; Gutierres, Jessié M; Bueno, Andressa; Agostinho, Paula; Zago, Adriana M; Vieira, Juliano; Frühauf, Pâmela; Cechella, José L; Nogueira, Cristina Wayne; Oliveira, Sara M; Rizzi, Caroline; Spanevello, Roselia M; Duarte, Marta M F; Duarte, Thiago; Dellagostin, Odir A; Andrade, Cinthia M

2017-07-01

Peripheral inflammatory stimuli may activate a brain neuroinflammatory processes with consequences in brain function. The present study investigated if anthocyanins (ANT) consumption was able to prevent the memory loss, the neuronal damage, and the neuroinflammatory processes triggered by the intraperitoneal lipopolysaccharide (LPS) administration. C57BL6 male mice were treated with ANT (30-100 mg/kg by gavage). With a single dose or during 10 days, before be challenged with LPS (250 μg/kg intraperitoneally single administration), a classical inductor of inflammation. The data obtained showed that ANT was able to confer protection against the memory impairment after 10 days of ANT treatment (100 mg/kg). This phytonutrient also prevented the hypothermia episode induced by LPS. Moreover, ANT prevented the increase in protein carbonyl, NOx, and MDA levels in the hippocampus and cerebral cortex (4 and 24 h) in animal challenged with LPS. ANT showed a protective effect on the increase in the pro-inflammatory cytokines content, especially Interleukin (IL)-1β, tumoral necrosis factor-α and on the reduction of IL-10 induced by LPS. ANT 100 mg/kg prevented the infiltration of peripheral immune cells in the hippocampus at 24 h post-LPS administration. In parallel, LPS increased the activity of myeloperoxidase in cortex and hippocampus, and ANT prevented this effect, also reducing microglia (Iba-1) and astrocyte (GFAP) immunoreactivity. Thus, our data support that ANT are a promising therapeutic component against brain disorders associated with process of neuroinflammation. Graphical Abstract ᅟ.

Triggered-Lightning Interaction with a Lightning Protective System: Current Distribution and Electromagnetic Environment

NASA Technical Reports Server (NTRS)

Mata, C. T.; Rakov, V. A.; Mata, A. G.

2010-01-01

A new comprehensive lightning instrumentation system has been designed for Launch Complex 39B (LC3913) at the Kennedy Space Center, Florida. This new instrumentation system includes the synchronized recording of six high-speed video cameras; currents through the nine downconductors of the new lightning protection system for LC3913; four dH/dt, 3-axis measurement stations; and five dE/dt stations composed of two antennas each. A 20:1 scaled down model of the new Lightning Protection System (LPS) of LC39B was built at the International Center for Lightning Research and Testing, Camp Blanding, FL. This scaled down lightning protection system was instrumented with the transient recorders, digitizers, and sensors to be used in the final instrumentation installation at LC3913. The instrumentation used at the ICLRT is also a scaled-down instrumentation of the LC39B instrumentation. The scaled-down LPS was subjected to seven direct lightning strikes and six (four triggered and two natural nearby flashes) in 2010. The following measurements were acquired at the ICLRT: currents through the nine downconductors; two dl-/dt, 3-axis stations, one at the center of the LPS (underneath the catenary wires), and another 40 meters south from the center of the LPS; ten dE/dt stations, nine of them on the perimeter of the LPS and one at the center of the LPS (underneath the catenary wire system); and the incident current. Data from representative events are presented and analyzed in this paper.

The Local and Systemic Immune Response to Intrauterine LPS in the Prepartum Mouse1

PubMed Central

Edey, Lydia F.; O'Dea, Kieran P.; Herbert, Bronwen R.; Hua, Renyi; Waddington, Simon N.; MacIntyre, David A.; Bennett, Philip R.; Takata, Masao; Johnson, Mark R.

2016-01-01

Inflammation plays a key role in human term and preterm labor (PTL). Intrauterine LPS has been widely used to model inflammation-induced complications of pregnancy, including PTL. It has been shown to induce an intense myometrial inflammatory cell infiltration, but the role of LPS-induced inflammatory cell activation in labor onset and fetal demise is unclear. We investigated this using a mouse model of PTL, where an intrauterine injection of 10 μg of LPS (serotype 0111:B4) was given at E16 of CD1 mouse pregnancy. This dose induced PTL at an average of 12.7 h postinjection in association with 85% fetal demise. Flow cytometry showed that LPS induced a dramatic systemic inflammatory response provoking a rapid and marked leucocyte infiltration into the maternal lung and liver in association with increased cytokine levels. Although there was acute placental inflammatory gene expression, there was no corresponding increase in fetal brain inflammatory gene expression until after fetal demise. There was marked myometrial activation of NFκB and MAPK/AP-1 systems in association with increased chemokine and cytokine levels, both of which peaked with the onset of parturition. Myometrial macrophage and neutrophil numbers were greater in the LPS-injected mice with labor onset only; prior to labor, myometrial neutrophils and monocytes numbers were greater in PBS-injected mice, but this was not associated with an earlier onset of labor. These data suggest that intrauterine LPS induces parturition directly, independent of myometrial inflammatory cell infiltration, and that fetal demise occurs without fetal inflammation. Intrauterine LPS provokes a marked local and systemic inflammatory response but with limited inflammatory cell infiltration into the myometrium or placenta. PMID:27760748

Maternal inflammation induces immune activation of fetal microglia and leads to disrupted microglia immune responses, behavior, and learning performance in adulthood.

PubMed

Schaafsma, Wandert; Basterra, Laura Bozal; Jacobs, Sabrina; Brouwer, Nieske; Meerlo, Peter; Schaafsma, Anne; Boddeke, Erik W G M; Eggen, Bart J L

2017-10-01

Maternal inflammation during pregnancy can have detrimental effects on embryonic development that persist during adulthood. However, the underlying mechanisms and insights in the responsible cell types are still largely unknown. Here we report the effect of maternal inflammation on fetal microglia, the innate immune cells of the central nervous system (CNS). In mice, a challenge with LPS during late gestation stages (days 15-16-17) induced a pro-inflammatory response in fetal microglia. Adult whole brain microglia of mice that were exposed to LPS during embryonic development displayed a persistent reduction in pro-inflammatory activation in response to a re-challenge with LPS. In contrast, hippocampal microglia of these mice displayed an increased inflammatory response to an LPS re-challenge. In addition, a reduced expression of brain-derived neurotrophic factor (BDNF) was observed in hippocampal microglia of LPS-offspring. Microglia-derived BDNF has been shown to be important for learning and memory processes. In line with these observations, behavioral- and learning tasks with mice that were exposed to maternal inflammation revealed reduced home cage activity, reduced anxiety and reduced learning performance in a T-maze. These data show that exposure to maternal inflammation during late gestation results in long term changes in microglia responsiveness during adulthood, which is different in nature in hippocampus compared to total brain microglia. Copyright © 2017 Elsevier Inc. All rights reserved.

Gamma-scintigraphy and early hepatocellular dysfunction during posttraumatic sepsis.

PubMed

McGinty, M P; Stewart, R M; Fabian, M J; Fabian, T C; Proctor, K G

1994-09-01

To determine whether the hepatic conjugation-detoxification function was altered during sepsis, the metabolism of bilirubin was measured with gamma-scintigraphy. Time-activity curves were generated after a radiolabeled bilirubin analog (technetium 99m-mebrofenin, hepatoiminodiacetic acid [HIDA]) was administered to anesthetized (fentanyl) mongrel pigs in the following conditions: control (n = 16); 30 minutes after 5 micrograms/kg intravenous Escherichia coli endotoxin (LPS; n = 6); 30 minutes after trauma (40% arterial hemorrhage plus soft tissue injury, n = 9); 72 hours after sham trauma (n = 6); 72 hours after fluid resuscitated trauma either before (n = 9) or 30 minutes after (n = 10) LPS administration. All were ventilated with 65% O2 and instrumented with pulmonary artery oximetric catheters. After trauma plus LPS, the rate of HIDA uptake was depressed 20% to 30% (p < 0.05), whereas its elimination half-time was increased almost threefold (p < 0.05) relative to before LPS administration. At the corresponding time after trauma alone or LPS alone, uptake was not altered and elimination was prolonged less than twofold (p < 0.05) relative to control. Perfusion differences could not explain these data because cardiac index (CI, ml/min/kg) was reduced to the same extent after trauma alone (62 +/- 10), LPS alone (79 +/- 6), or trauma plus LPS (71 +/- 6) compared with control (102 +/- 5), sham (112 +/- 11), or pre-LPS (120 +/- 10) (p < 0.05, respectively). Levels of serum alanine aminotransferase and creatine kinase were both elevated (p < 0.05) 72 hours after resuscitation, but there were no added increments caused by LPS administration. Levels of other enzymes and plasma bilirubin were not increased by trauma or LPS alone or in combination. Changes in HIDA uptake-excretion within 30 minutes of LPS after resuscitated trauma coincided with neutropenia and pulmonary hypertension and preceded a hyperdynamic inflammatory state characterized by increased CI (194 +/- 19 ml/min/kg, p < 0.05) at 90 +/- 13 minutes, decreased systemic vascular resistance (0.48 +/- 0.04 mm Hg per ml/min/kg, p < 0.05 relative to 1.08 +/- 0.07 for control or 0.88 +/- 0.08 for pre-LPS) at 81 +/- 8 minutes, and increased systemic O2 consumption (6.96 +/- 0.93 vs 4.16 +/- 0.23 ml O2/min/kg, p < 0.05 relative to pre-LPS) at 96 +/- 12 minutes. (1) A prior episode of resuscitated traumatic shock exhausts hepatic reserve and this occult dysfunction in the conjugation-detoxification system or bilirubin metabolism is unmasked by LPS; (2) hepatic dysfunction could have a role in the pathogenesis of the hyperdynamic circulatory response evoked by LPS because HIDA clearance was reduced before CI increased or systemic vascular resistance decreased; (3) HIDA clearance is a rapid, reliable, and inexpensive estimate of bilirubin metabolism that may have a practical application in patients with septic trauma or others with occult liver dysfunction.

Flow cytometric analysis of crayfish haemocytes activated by lipopolysaccharides

USGS Publications Warehouse

Cardenas, W.; Dankert, J.R.; Jenkins, J.A.

2004-01-01

Lipopolysaccharides (LPS) from Gram-negative bacteria are strong stimulators of white river crayfish, Procambarus zonangulus, haemocytes in vitro. Following haemocyte treatment with LPS and with LPS from rough mutant R5 (LPS Rc) from Salmonella minnesota, flow cytometric analysis revealed a conspicuous and reproducible decrease in cell size as compared to control haemocytes. These LPS molecules also caused a reduction in haemocyte viability as assessed by flow cytometry with the fluorescent dyes calcein-AM and ethidium homodimer. The onset of cell size reduction was gradual and occurred prior to cell death. Haemocytes treated with LPS from S. minnesota without the Lipid A moiety (detoxified LPS) decreased in size without a reduction of viability. The action of LPS on crayfish haemocytes appeared to be related to the activation of the prophenoloxidase system because phenoloxidase (PO)-specific activity in the supernatants from control and detoxified LPS-treated cells was significantly lower than that from LPS and LPS-Rc treated cells (P < 0.05). Furthermore, addition of trypsin inhibitor to the LPS treatments caused noticeable delays in cell size and viability changes. These patterns of cellular activation by LPS formulations indicated that crayfish haemocytes react differently to the polysaccharide and lipid A moieties of LPS, where lipid A is cytotoxic and the polysaccharide portion is stimulatory. These effects concur with the general pattern of mammalian cell activation by LPS, thereby indicting commone innate immune recognition mechanisms to bacterial antigens between cells from mammals and invertebrates. These definitive molecular approaches used to verify and identify mechanisms of invertbrate haemocyte responses to LPS could be applied with other glycoconjugates, soluble mediators, or xenobiotic compounds.

Metabolic Cost of the Activation of Immune Response in the Fish-Eating Myotis (Myotis vivesi): The Effects of Inflammation and the Acute Phase Response

PubMed Central

Otálora-Ardila, Aída; Herrera M., L. Gerardo; Flores-Martínez, José Juan; Welch, Kenneth C.

2016-01-01

Inflammation and activation of the acute phase response (APR) are energetically demanding processes that protect against pathogens. Phytohaemagglutinin (PHA) and lipopolysaccharide (LPS) are antigens commonly used to stimulate inflammation and the APR, respectively. We tested the hypothesis that the APR after an LPS challenge was energetically more costly than the inflammatory response after a PHA challenge in the fish-eating Myotis bat (Myotis vivesi). We measured resting metabolic rate (RMR) after bats were administered PHA and LPS. We also measured skin temperature (Tskin) after the LPS challenge and skin swelling after the PHA challenge. Injection of PHA elicited swelling that lasted for several days but changes in RMR and body mass were not significant. LPS injection produced a significant increase in Tskin and in RMR, and significant body mass loss. RMR after LPS injection increased by 140–185% and the total cost of the response was 6.50 kJ. Inflammation was an energetically low-cost process but the APR entailed a significant energetic investment. Examination of APR in other bats suggests that the way in which bats deal with infections might not be uniform. PMID:27792729

Metabolic Cost of the Activation of Immune Response in the Fish-Eating Myotis (Myotis vivesi): The Effects of Inflammation and the Acute Phase Response.

PubMed

Otálora-Ardila, Aída; Herrera M, L Gerardo; Flores-Martínez, José Juan; Welch, Kenneth C

2016-01-01

Inflammation and activation of the acute phase response (APR) are energetically demanding processes that protect against pathogens. Phytohaemagglutinin (PHA) and lipopolysaccharide (LPS) are antigens commonly used to stimulate inflammation and the APR, respectively. We tested the hypothesis that the APR after an LPS challenge was energetically more costly than the inflammatory response after a PHA challenge in the fish-eating Myotis bat (Myotis vivesi). We measured resting metabolic rate (RMR) after bats were administered PHA and LPS. We also measured skin temperature (Tskin) after the LPS challenge and skin swelling after the PHA challenge. Injection of PHA elicited swelling that lasted for several days but changes in RMR and body mass were not significant. LPS injection produced a significant increase in Tskin and in RMR, and significant body mass loss. RMR after LPS injection increased by 140-185% and the total cost of the response was 6.50 kJ. Inflammation was an energetically low-cost process but the APR entailed a significant energetic investment. Examination of APR in other bats suggests that the way in which bats deal with infections might not be uniform.

Designed β-Boomerang Antiendotoxic and Antimicrobial Peptides

PubMed Central

Bhunia, Anirban; Mohanram, Harini; Domadia, Prerna N.; Torres, Jaume; Bhattacharjya, Surajit

2009-01-01

Lipopolysaccharide (LPS), an integral part of the outer membrane of Gram-negative bacteria, is involved in a variety of biological processes including inflammation, septic shock, and resistance to host-defense molecules. LPS also provides an environment for folding of outer membrane proteins. In this work, we describe the structure-activity correlation of a series of 12-residue peptides in LPS. NMR structures of the peptides derived in complex with LPS reveal boomerang-like β-strand conformations that are stabilized by intimate packing between the two aromatic residues located at the 4 and 9 positions. This structural feature renders these peptides with a high ability to neutralize endotoxicity, >80% at 10 nm concentration, of LPS. Replacements of these aromatic residues either with Ala or with Leu destabilizes the boomerang structure with the concomitant loss of antiendotoxic and antimicrobial activities. Furthermore, the aromatic packing stabilizing the β-boomerang structure in LPS is found to be maintained even in a truncated octapeptide, defining a structured LPS binding motif. The mode of action of the active designed peptides correlates well with their ability to perturb LPS micelle structures. Fourier transform infrared spectroscopy studies of the peptides delineate β-type conformations and immobilization of phosphate head groups of LPS. Trp fluorescence studies demonstrated selective interactions with LPS and the depth of insertion into the LPS bilayer. Our results demonstrate the requirement of LPS-specific structures of peptides for endotoxin neutralizations. In addition, we propose that structures of these peptides may be employed to design proteins for the outer membrane. PMID:19520860

Systemic LPS and inflammatory response during consecutive days of exercise in heat.

PubMed

Barberio, M D; Elmer, D J; Laird, R H; Lee, K A; Gladden, B; Pascoe, D D

2015-03-01

This investigation studied circulating LPS activity, potential intestinal damage, and the systemic inflammatory response (SIR) during the exercise heat acclimation process. 8 healthy males (Age=24±3 years) ran in a hot environment on 5 consecutive days until core temperature (Tc) was elevated 2°C above rest. Plasma was obtained pre-, post-, 1 h post-, and 3 h post-exercise on the 1(st), 3(rd), and 5(th) day of exercise and analyzed for TNF-α, IL-6, IL-10, IL-1ra, LPS, and intestinal fatty acid-binding protein (I-FABP). Plasma LPS (1.1 EU·ml(-1)±0.1 vs. 0.7 EU·ml(-1)±0.03; P<0.01) and I-FABP (930.7 pg·ml(-1)±149.0 vs. 640.2 pg·ml(-1)±125.0; P<0.001) were significantly increased post-exercise each. The SIR remained largely unchanged during the study except for TNF-α. Plasma TNF-α was significantly lower on Day 5 at 1 h (3.2 pg·ml(-1)±0.6 vs. 4.5 pg·ml(-1)±0.8; P=0.01) and 3 h (3.6 pg·ml(-1)±0.8 vs. 4.8 pg·ml(-1)±0.9; P=0.05) post-exercise as compared to Day 1. Findings indicate that adaptations to exercise in the heat resulting in reductions of intestinal damage and plasma LPS activity require longer time periods in moderately trained males. © Georg Thieme Verlag KG Stuttgart · New York.

MHC class II molecules control murine B cell responsiveness to lipopolysaccharide stimulation.

PubMed

Rodo, Joana; Gonçalves, Lígia A; Demengeot, Jocelyne; Coutinho, António; Penha-Gonçalves, Carlos

2006-10-01

LPS is a strong stimulator of the innate immune system and inducer of B lymphocyte activation. Two TLRs, TLR4 and RP105 (CD180), have been identified as mediators of LPS signaling in murine B cells, but little is known about genetic factors that are able to control LPS-induced cell activation. We performed a mouse genome-wide screen that aside from identifying a controlling locus mapping in the TLR4 region (logarithm of odds score, 2.77), also revealed that a locus closely linked to the MHC region (logarithm of odds score, 3.4) governed B cell responsiveness to LPS stimulation. Using purified B cells obtained from MHC congenic strains, we demonstrated that the MHC(b) haplotype is accountable for higher cell activation, cell proliferation, and IgM secretion, after LPS stimulation, when compared with the MHC(d) haplotype. Furthermore, B cells from MHC class II(-/-) mice displayed enhanced activation and proliferation in response to LPS. In addition, we showed that the MHC haplotype partially controls expression of RP105 (a LPS receptor molecule), following a pattern that resembles the LPS responsiveness phenotype. Together, our results strongly suggest that murine MHC class II molecules play a role in constraining the B cell response to LPS and that genetic variation at the MHC locus is an important component in controlling B cell responsiveness to LPS stimulation. This work raises the possibility that constraining of B cell responsiveness by MHC class II molecules may represent a functional interaction between adaptive and innate immune systems.

Structural diversity of Burkholderia pseudomallei lipopolysaccharides affects innate immune signaling

PubMed Central

Norris, Michael H.; Schweizer, Herbert P.

2017-01-01

Burkholderia pseudomallei (Bp) causes the disease melioidosis. The main cause of mortality in this disease is septic shock triggered by the host responding to lipopolysaccharide (LPS) components of the Gram-negative outer membrane. Bp LPS is thought to be a weak inducer of the host immune system. LPS from several strains of Bp were purified and their ability to induce the inflammatory mediators TNF-α and iNOS in murine macrophages at low concentrations was investigated. Innate and adaptive immunity qPCR arrays were used to profile expression patterns of 84 gene targets in response to the different LPS types. Additional qPCR validation confirmed large differences in macrophage response. LPS from a high-virulence serotype B strain 576a and a virulent rough central nervous system tropic strain MSHR435 greatly induced the innate immune response indicating that the immunopathogenesis of these strains is different than in infections with strains similar to the prototype strain 1026b. The accumulation of autophagic vesicles was also increased in macrophages challenged with highly immunogenic Bp LPS. Gene induction and concomitant cytokine secretion profiles of human PBMCs in response to the various LPS were also investigated. MALDI-TOF/TOF was used to probe the lipid A portions of the LPS, indicating substantial structural differences that likely play a role in host response to LPS. These findings add to the evolving knowledge of host-response to bacterial LPS, which can be used to better understand septic shock in melioidosis patients and in the rational design of vaccines. PMID:28453531

The PI3K/Akt pathway is required for LPS activation of microglial cells.

PubMed

Saponaro, Concetta; Cianciulli, Antonia; Calvello, Rosa; Dragone, Teresa; Iacobazzi, Francesco; Panaro, Maria Antonietta

2012-10-01

Upregulation of inflammatory responses in the brain is associated with a number of neurodegenerative diseases. Microglia are activated in neurodegenerative diseases, producing pro-inflammatory mediators. Critically, lipopolysaccharide (LPS)-induced microglial activation causes dopaminergic neurodegeneration in vitro and in vivo. The signaling mechanisms triggered by LPS to stimulate the release of pro-inflammatory mediators in microglial cells are still incompletely understood. To further explore the mechanisms of LPS-mediated inflammatory response of microglial cells, we studied the role of phosphatidylinositol 3-kinase (PI3K)/Akt signal transduction pathways known to be activated by toll-like receptor-4 signaling through LPS. In the current study, we report that the activation profile of LPS-induced pAkt activation preceded those of LPS-induced NF-κB activation, suggesting a role for PI3K/Akt in the pathway activation of NF-κB-dependent inflammatory responses of activated microglia. These results, providing the first evidence that PI3K dependent signaling is involved in the inflammatory responses of microglial cells following LPS stimulation, may be useful in preventing inflammatory based neurodegenerative processes.

Complement system and immunological mediators: Their involvements in the induced inflammatory process by Androctonus australis hector venom and its toxic components.

PubMed

Bekkari, Nadjia; Martin-Eauclaire, Marie-France; Laraba-Djebari, Fatima

2015-01-01

Androctonus australis hector scorpion venom is well known by its high toxicity, it induces massive release of neurotransmitters that lead to pathophysiological disorders in cardiovascular, neuro-hormonal and immune systems. Previous studies have shown the relationship between the severity of scorpion envenoming and immune system activation. This study was assessed to investigate the involvement of complement system and inflammatory mediators after sublethal injection of Aah venom, its toxic fraction (FtoxG50) and its main toxins (AahI and AahII) into NMRI mice. The Activation complement system by the venom is also compared to that induced of lipopolysaccharides (LPS). Obtained results showed that seric complement system (CS) is activated by the venom and by its toxic components; this activation is more pronounced into liver tissue when toxic components (FtoxG50, AahI or AahII) are used. Increase of cytokine levels (IL1β, TNFα and ICAM) into hepatic tissue induced by AahI or AahII neurotoxins is correlated with tissue alterations. Aprotinin, a non specific inhibitor of complement system seems to be able to reduce CS consumption and to restore partially the induced tissue damage by venom. The mechanisms by which toxic fraction or LPS induced the activation of complement system seem to be different. Sensitivity of hepatic tissue is more pronounced after FtoxG50 injection; however lung tissue is more sensible to LPS than FoxG50. Copyright © 2015 Elsevier GmbH. All rights reserved.

Designed beta-boomerang antiendotoxic and antimicrobial peptides: structures and activities in lipopolysaccharide.

PubMed

Bhunia, Anirban; Mohanram, Harini; Domadia, Prerna N; Torres, Jaume; Bhattacharjya, Surajit

2009-08-14

Lipopolysaccharide (LPS), an integral part of the outer membrane of Gram-negative bacteria, is involved in a variety of biological processes including inflammation, septic shock, and resistance to host-defense molecules. LPS also provides an environment for folding of outer membrane proteins. In this work, we describe the structure-activity correlation of a series of 12-residue peptides in LPS. NMR structures of the peptides derived in complex with LPS reveal boomerang-like beta-strand conformations that are stabilized by intimate packing between the two aromatic residues located at the 4 and 9 positions. This structural feature renders these peptides with a high ability to neutralize endotoxicity, >80% at 10 nM concentration, of LPS. Replacements of these aromatic residues either with Ala or with Leu destabilizes the boomerang structure with the concomitant loss of antiendotoxic and antimicrobial activities. Furthermore, the aromatic packing stabilizing the beta-boomerang structure in LPS is found to be maintained even in a truncated octapeptide, defining a structured LPS binding motif. The mode of action of the active designed peptides correlates well with their ability to perturb LPS micelle structures. Fourier transform infrared spectroscopy studies of the peptides delineate beta-type conformations and immobilization of phosphate head groups of LPS. Trp fluorescence studies demonstrated selective interactions with LPS and the depth of insertion into the LPS bilayer. Our results demonstrate the requirement of LPS-specific structures of peptides for endotoxin neutralizations. In addition, we propose that structures of these peptides may be employed to design proteins for the outer membrane.

Milk Thistle Extract and Silymarin Inhibit Lipopolysaccharide Induced Lamellar Separation of Hoof Explants in Vitro

PubMed Central

Reisinger, Nicole; Schaumberger, Simone; Nagl, Veronika; Hessenberger, Sabine; Schatzmayr, Gerd

2014-01-01

The pathogenesis of laminitis is not completely identified and the role of endotoxins (lipopolysaccharides, LPS) in this process remains unclear. Phytogenic substances, like milk thistle (MT) and silymarin, are known for their anti-inflammatory and antioxidant properties and might therefore have the potential to counteract endotoxin induced effects on the hoof lamellar tissue. The aim of our study was to investigate the influence of endotoxins on lamellar tissue integrity and to test if MT and silymarin are capable of inhibiting LPS-induced effects in an in vitro/ex vivo model. In preliminary tests, LPS neutralization efficiency of these phytogenics was determined in an in vitro neutralization assay. Furthermore, tissue explants gained from hooves of slaughter horses were tested for lamellar separation after incubation with different concentrations of LPS. By combined incubation of explants with LPS and either Polymyxin B (PMB; positive control), MT or silymarin, the influence of these substances on LPS-induced effects was assessed. In the in vitro neutralization assay, MT and silymarin reduced LPS concentrations by 64% and 75%, respectively, in comparison PMB reduced 98% of the LPS concentration. In hoof explants, LPS led to a concentration dependent separation. Accordantly, separation force was significantly decreased by 10 µg/mL LPS. PMB, MT and silymarin could significantly improve tissue integrity of explants incubated with 10 µg/mL LPS. This study showed that LPS had a negative influence on the structure of hoof explants in vitro. MT and silymarin reduced endotoxin activity and inhibited LPS-induced effects on the lamellar tissue. Hence, MT and silymarin might be used to support the prevention of laminitis and should be further evaluated for this application. PMID:25290524

Milk thistle extract and silymarin inhibit lipopolysaccharide induced lamellar separation of hoof explants in vitro.

PubMed

Reisinger, Nicole; Schaumberger, Simone; Nagl, Veronika; Hessenberger, Sabine; Schatzmayr, Gerd

2014-10-06

The pathogenesis of laminitis is not completely identified and the role of endotoxins (lipopolysaccharides, LPS) in this process remains unclear. Phytogenic substances, like milk thistle (MT) and silymarin, are known for their anti-inflammatory and antioxidant properties and might therefore have the potential to counteract endotoxin induced effects on the hoof lamellar tissue. The aim of our study was to investigate the influence of endotoxins on lamellar tissue integrity and to test if MT and silymarin are capable of inhibiting LPS-induced effects in an in vitro/ex vivo model. In preliminary tests, LPS neutralization efficiency of these phytogenics was determined in an in vitro neutralization assay. Furthermore, tissue explants gained from hooves of slaughter horses were tested for lamellar separation after incubation with different concentrations of LPS. By combined incubation of explants with LPS and either Polymyxin B (PMB; positive control), MT or silymarin, the influence of these substances on LPS-induced effects was assessed. In the in vitro neutralization assay, MT and silymarin reduced LPS concentrations by 64% and 75%, respectively, in comparison PMB reduced 98% of the LPS concentration. In hoof explants, LPS led to a concentration dependent separation. Accordantly, separation force was significantly decreased by 10 µg/mL LPS. PMB, MT and silymarin could significantly improve tissue integrity of explants incubated with 10 µg/mL LPS. This study showed that LPS had a negative influence on the structure of hoof explants in vitro. MT and silymarin reduced endotoxin activity and inhibited LPS-induced effects on the lamellar tissue. Hence, MT and silymarin might be used to support the prevention of laminitis and should be further evaluated for this application.

Doxycycline Attenuates Lipopolysaccharide-Induced Microvascular Endothelial Cell Derangements.

PubMed

Wiggins-Dohlvik, Katie; Stagg, Hayden W; Han, Min Suk; Alluri, Himakarnika; Oakley, Ryan P; Anasooya Shaji, Chinchusha; Davis, Matthew L; Tharakan, Binu

2016-06-01

Lipopolysaccharide (LPS) is known to induce vascular derangements. The pathophysiology involved therein is unknown, but matrix metalloproteinases (MMPs) may be an important mediator. We hypothesized that in vitro LPS provokes vascular permeability, damages endothelial structural proteins, and increases MMP activity; that in vivo LPS increases permeability and fluid requirements; and that the MMP inhibitor doxycycline mitigates such changes. Rat lung microvascular endothelial cells were divided into four groups: control, LPS, LPS plus doxycycline, and doxycycline. Permeability, structural proteins β-catenin and Filamentous-actin, and MMP-9 activity were examined. Sprauge Dawley rats were divided into sham, IV LPS, and IV LPS plus IV doxycycline groups. Mesenteric postcapillary venules were observed. Blood pressure was measured as animals were resuscitated and fluid requirements were compared. Statistical analysis was conducted using Student's t-test and ANOVA. In vitro LPS increased permeability, damaged adherens junctions, induced actin stress fiber formation, and increased MMP-9 enzyme activity. In vivo, IV LPS administration induced vascular permeability. During resuscitation, significantly more fluid was necessary to maintain normotension in the IV LPS group. Doxycycline mitigated all derangements observed. We conclude that LPS increases permeability, damages structural proteins, and increases MMP-9 activity in endothelial cells. Additionally, endotoxemia induces hyperpermeability and increases the amount of IV fluid required to maintain normotension in vivo. Doxycycline mitigates such changes both in vitro and in vivo. Our findings illuminate the possible role of matrix metalloproteinases in the pathophysiology of lipopolysaccharide-induced microvascular hyperpermeability and pave the way for better understanding and treatment of this process.

Dopaminergic neuronal injury in the adult rat brain following neonatal exposure to lipopolysaccharide and the silent neurotoxicity

PubMed Central

Fan, Lir-Wan; Tien, Lu-Tai; Zheng, Baoying; Pang, Yi; Lin, Rick C. S.; Simpson, Kimberly L.; Ma, Tangeng; Rhodes, Philip G.; Cai, Zhengwei

2010-01-01

Our previous studies have shown that neonatal exposure to lipopolysaccharide (LPS) resulted in motor dysfunction and dopaminergic neuronal injury in the juvenile rat brain. To further examine whether neonatal LPS exposure has persisting effects in adult rats, motor behaviors were examined from postnatal day 7 (P7) to P70 and brain injury was determined in P70 rats following an intracerebral injection of LPS (1 mg/kg) in P5 Sprague-Dawley male rats. Although neonatal LPS exposure resulted in hyperactivity in locomotion and stereotyped tasks, and other disturbances of motor behaviors, the impaired motor functions were spontaneously recovered by P70. On the other hand, neonatal LPS-induced injury to the dopaminergic system such as the loss of dendrites and reduced tyrosine hydroxylase immunoreactivity in the substantia nigra persisted in P70 rats. Neonatal LPS exposure also resulted in sustained inflammatory responses in the P70 rat brain, as indicated by an increased number of activated microglia and elevation of interleukin-1β and interleukin-6 content in the rat brain. In addition, when challenged with methamphetamine (METH, 0.5 mg/kg) subcutaneously, rats with neonatal LPS exposure had significantly increased responses in METH-induced locomotion and stereotypy behaviors as compared to those without LPS exposure. These results indicate that although neonatal LPS-induced neurobehavioral impairment is spontaneously recoverable, the LPS exposure-induced persistent injury to the dopaminergic system and the chronic inflammation may represent the existence of silent neurotoxicity. Our data further suggest that the compromised dendritic mitochondrial function might contribute, at least partially, to the silent neurotoxicity. PMID:20875849

Solar energy emplacement developer

NASA Technical Reports Server (NTRS)

Mortensen, Michael; Sauls, Bob

1991-01-01

A preliminary design was developed for a Lunar Power System (LPS) composed of photovoltaic arrays and microwave reflectors fabricated from lunar materials. The LPS will collect solar energy on the surface of the Moon, transform it into microwave energy, and beam it back to Earth where it will be converted into usable energy. The Solar Energy Emplacement Developer (SEED) proposed will use a similar sort of solar energy collection and dispersement to power the systems that will construct the LPS.

Bacterial endotoxin adhesion to different types of orthodontic adhesives

PubMed Central

ROMUALDO, Priscilla Coutinho; GUERRA, Thaís Rodrigues; ROMANO, Fábio Lourenço; da SILVA, Raquel Assed Bezerra; BRANDÃO, Izaíra Tincani; SILVA, Célio Lopes; da SILVA, Lea Assed Bezerra; NELSON-FILHO, Paulo

2017-01-01

Abstract Bacterial endotoxin (LPS) adhesion to orthodontic brackets is a known contributing factor to inflammation of the adjacent gingival tissues. Objective The aim of this study was to assess whether LPS adheres to orthodontic adhesive systems, comparing two commercial brands. Material and Methods Forty specimens were fabricated from Transbond XT and Light Bond composite and bonding agent components (n=10/component), then contaminated by immersion in a bacterial endotoxin solution. Contaminated and non-contaminated acrylic resin samples were used as positive and negative control groups, respectively. LPS quantification was performed by the Limulus Amebocyte Lysate QCL-1000™ test. Data obtained were scored and subjected to the Chi-square test using a significance level of 5%. Results There was endotoxin adhesion to all materials (p<0.05). No statistically significant difference was found between composites/bonding agents and acrylic resin (p>0.05). There was no significant difference (p>0.05) among commercial brands. Affinity of endotoxin was significantly greater for the bonding agents (p=0.0025). Conclusions LPS adhered to both orthodontic adhesive systems. Regardless of the brand, the endotoxin had higher affinity for the bonding agents than for the composites. There is no previous study assessing the affinity of LPS for orthodontic adhesive systems. This study revealed that LPS adheres to orthodontic adhesive systems. Therefore, additional care is recommended to orthodontic applications of these materials. PMID:28877283

Evaluation of lactoperoxidase system treatment to reduce anthracnose, stem-end rot, and bacterial black spot development during storage of mangoes.

PubMed

Le Nguyen, Doan Duy; Ducamp, Marie-Noelle; Dornier, Manuel; Montet, Didier; Reynes, Max; Loiseau, Gérard

2005-08-01

The lactoperoxidase system (LPS) was evaluated for the prevention of postharvest diseases caused by Xanthomonas campestris, Botryodiplodia theobromae, and Colletotrichum gloeosporioides in 'Keitt' and 'Kent' mangoes. The LPS treatment significantly reduced the disease development on both cultivars after storage at 12 degrees C for 2 weeks, which was followed by a ripening at 25 degrees C. The LPS treatment did not alter the sensory quality of mango fruits (color, firmness, titrable acidity, and total soluble solids) when compared to untreated fruits. The LPS thus presents good potential alternative to the chemical fungicides traditionally used to improve the shelf life of mangoes.

Odor Signals of Immune Activation and CNS Inflammation

DTIC Science & Technology

2014-12-01

inflammation results in detectable alteration of body odor and that traumatic brain injury (TBI) might similarly produce volatile metabolites specific to...Because both LPS and TBI elicit inflammatory processes and LPS-induced inflammation induces body odor changes, we hypothesized that (1) TBI would...induce a distinct change in body odor and (2) this change would resemble the change induced by LPS. Mice receiving surgery and lateral fluid percussion

Boric acid inhibits LPS-induced TNF-alpha formation through a thiol-dependent mechanism in THP-1 cells.

PubMed

Cao, Jun; Jiang, Liping; Zhang, Xiaomei; Yao, Xiaofeng; Geng, Chengyan; Xue, Xiangxin; Zhong, Laifu

2008-01-01

Oxidative stress plays an important role during inflammatory diseases and antioxidant administration to diminish oxidative stress may arrest inflammatory processes. Boron has been implicated to modulate certain inflammatory mediators and regulate inflammatory processes. Here we investigated the role of the tripeptide glutathione (GSH) in modulating the effects of boric acid (BA) on lipopolysaccharide (LPS)-induced tumor necrosis factor alpha (TNF-alpha) formation in THP-1 monocytes. Interestingly, we found that BA had no significant effects on both TNF-alpha production and intracellular GSH contents, whereas it could inhibit LPS-induced TNF-alpha formation and ameliorated the d,l-buthionine-S,R-sulfoximine (BSO)-induced GSH depletion. Twenty-four hour incubation with BSO induced a decrease of the intracellular GSH and an increase of TNF-alpha. Treatment with N-acetyl-l-cysteine (NAC) did not significantly increase intracellular content of GSH but significantly reduced the secretion of TNF-alpha. BSO-pretreatment for 24h enhanced the LPS-induced secretion and mRNA expression of TNF-alpha further. BA inhibited LPS-stimulated TNF-alpha formation was also seen after GSH depletion by BSO. These results indicate that BA may have anti-inflammatory effect in the LPS-stimulated inflammation and the effect of BA on TNF-alpha secretion may be induced via a thiol-dependent mechanism.

Houttuynia cordata, a novel and selective COX-2 inhibitor with anti-inflammatory activity.

PubMed

Li, Weifeng; Zhou, Ping; Zhang, Yanmin; He, Langchong

2011-01-27

Houttuynia cordata Thunb. (Saururaceae; HC) has been long used in traditional oriental medicine for the treatment of inflammation diseases. Modern research has implicated inducible cyclooxygenase-2 (COX-2) as a key regulator of the inflammatory process. In the present study, we aimed to investigate the effect of HC on COX-2. We examined the effects of HC on lipopolysaccharide (LPS)-induced prostaglandin (PG) E(2) production, an indirect indicator of COX-2 activity, and COX-2 gene and protein expression in mouse peritoneal macrophages. LPS-induced mouse peritoneal macrophages were employed as an in vitro model system. LPS-induced PGE(2) production was assessed by enzyme-linked immunosorbant assay and COX-2 protein expression was assessed by Western blot assay. The results showed that HC was able to inhibit the release of LPS-induced PGE(2) from mouse peritoneal macrophages (IC50 value: 44.8 μg/mL). Moreover, the inhibitory activity of HC essential oil elicited a dose-dependent inhibition of COX-2 enzyme activity (IC50 value: 30.9 μg/mL). HC was also found to cause reduction in LPS-induced COX-2 mRNA and protein expression, but did not affect COX-1 expression. The non-steroidal anti-inflammatory drug (NSAID) and specific COX-2 inhibitor NS398 functioned similarly in LPS-induced mouse peritoneal macrophages. Taken together, our data suggest HC mediates inhibition of COX-2 enzyme activity and can affect related gene and protein expression. HC works by a mechanism of action similar to that of NSAIDs. These results add a novel aspect to the biological profile of HC. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Aging exacerbates depressive-like behavior in mice in response to activation of the peripheral innate immune system.

PubMed

Godbout, Jonathan P; Moreau, Maïté; Lestage, Jacques; Chen, Jing; Sparkman, Nathan L; O'Connor, Jason; Castanon, Nathalie; Kelley, Keith W; Dantzer, Robert; Johnson, Rodney W

2008-09-01

Exposure to peripheral infections may be permissive to cognitive and behavioral complications in the elderly. We have reported that peripheral stimulation of the innate immune system with lipopolysaccharide (LPS) causes an exaggerated neuroinflammatory response and prolonged sickness behavior in aged BALB/c mice. Because LPS also causes depressive behavior, the purpose of this study was to determine whether aging is associated with an exacerbated depressive-like response. We confirmed that LPS (0.33 mg/kg intraperitoneal) induced a protracted sickness response in aged mice with reductions in locomotor and feeding activities 24 and 48 h postinjection, when young adults had fully recovered. When submitted to the forced swim test 24 h post-LPS, both young adult and aged mice exhibited an increased duration of immobility. However, when submitted to either the forced swim test or the tail suspension test 72 h post-LPS, an increased duration of immobility was evident only in aged mice. This prolonged depressive-like behavior in aged LPS-treated mice was associated with a more pronounced induction of peripheral and brain indoleamine 2,3-dioxygenase and a markedly higher turnover rate of brain serotonin (as measured by the ratio of 5-hydroxy-indoleacetic acid over 5-hydroxy-tryptamine) compared to young adult mice at 24 post-LPS injection. These results provide the first evidence that age-associated reactivity of the brain cytokine system could play a pathophysiological role in the increased prevalence of depression observed in the elderly.

Altered TNF-Alpha, Glucose, Insulin and Amino Acids in Islets Langerhans Cultured in a Microgravity Model System

NASA Technical Reports Server (NTRS)

Tobin, Brian W.; Leeper-Woodford, Sandra K.; Hashemi, Brian B.; Smith, Scott M.; Sams, Clarence F.

2001-01-01

The present studies were designed to determine effects of a microgravity model system upon lipopolysaccharide (LPS) stimulated tumor necrosis factor alpha (TNF-alpha) activity and indices of insulin and fuel homeostasis of pancreatic islets of Langerhans. Islets (1726+/-1 17,150 u IEU) from Wistar Furth rats were treated as: 1) HARV (High Aspect Ratio Vessel cell culture) , 2) HARV plus LPS, 3) static culture, 4) static culture plus LPS. TNF-alpha (L929 cytotoxicity assay) was significantly increased in LPS-induced HARV and static cultures, yet the increase was more pronounced in the static culture group (p<0.05). A decrease in insulin concentration was demonstrated in the LPS stimulated HARV culture (p<0.05). We observed a greater glucose concentration and increased disappearance of arginine in islets cultured in HARVs. While nitrogenous compound analysis indicated a ubiquitous reliance upon glutamine in all experimental groups, arginine was converted to ornithine at a two-fold greater rate in the islets cultured in the HARV microgravity model system (p<0.05). These studies demonstrate alterations in LPS induced TNF-alpha production of pancreatic islets of Langerhans, favoring a lesser TNF activity in the HARV. These alterations in fuel homeostasis may be promulgated by gravity averaged cell culture methods or by three dimensional cell assembly.

Endotoxin, Toll-like Receptor-4, and Atherosclerotic Heart Disease

PubMed Central

Horseman, Michael A.; Surani, Salim; Bowman, John D.

2017-01-01

Background: Endotoxin is a lipopolysaccharide (LPS) constituent of the outer membrane of most gram negative bacteria. Ubiquitous in the environment, it has been implicated as a cause or con-tributing factor in several disparate disorders from sepsis to heatstroke and Type II diabetes mellitus. Starting at birth, the innate immune system develops cellular defense mechanisms against environmen-tal microbes that are in part modulated through a series of receptors known as toll-like receptors. Endo-toxin, often referred to as LPS, binds to toll-like receptor 4 (TLR4)/ myeloid differentiation protein 2 (MD2) complexes on various tissues including cells of the innate immune system, smooth muscle and endothelial cells of blood vessels including coronary arteries, and adipose tissue. Entry of LPS into the systemic circulation ultimately leads to intracellular transcription of several inflammatory mediators. The subsequent inflammation has been implicated in the development and progression atherosclerosis and subsequent coronary artery disease and heart failure. Objective: The potential roles of endotoxin and TLR4 are reviewed regarding their role in the pathogen-esis of atherosclerotic heart disease. Conclusion: Atherosclerosis is initiated by inflammation in arterial endothelial and subendothelial cells, and inflammatory processes are implicated in its progression to clinical heart disease. Endotoxin and TLR4 play a central role in the inflammatory process, and represent potential targets for therapeutic intervention. Therapy with HMG-CoA inhibitors may reduce the expression of TLR4 on monocytes. Other therapeutic interventions targeting TLR4 expression or function may prove beneficial in athero-sclerotic disease prevention and treatment.

Type I IFNs Are Required to Promote Central Nervous System Immune Surveillance through the Recruitment of Inflammatory Monocytes upon Systemic Inflammation

PubMed Central

Peralta Ramos, Javier María; Bussi, Claudio; Gaviglio, Emilia Andrea; Arroyo, Daniela Soledad; Baez, Natalia Soledad; Rodriguez-Galan, Maria Cecilia; Iribarren, Pablo

2017-01-01

Brain-resident microglia and peripheral migratory leukocytes play essential roles in shaping the immune response in the central nervous system. These cells activate and migrate in response to chemokines produced during active immune responses and may contribute to the progression of neuroinflammation. Herein, we addressed the participation of type I–II interferons in the response displayed by microglia and inflammatory monocytes to comprehend the contribution of these cytokines in the establishment and development of a neuroinflammatory process. Following systemic lipopolysaccharide (LPS) challenge, we found glial reactivity and an active recruitment of CD45hi leukocytes close to CD31+ vascular endothelial cells in circumventricular organs. Isolated CD11b+ CD45hi Ly6Chi Ly6G−-primed inflammatory monocytes were able to induce T cell proliferation, unlike CD11b+ CD45lo microglia. Moreover, ex vivo re-stimulation with LPS exhibited an enhancement of T cell proliferative response promoted by inflammatory monocytes. These myeloid cells also proved to be recruited in a type I interferon-dependent fashion as opposed to neutrophils, unveiling a role of these cytokines in their trafficking. Together, our results compares the phenotypic and functional features between tissue-resident vs peripheral recruited cells in an inflamed microenvironment, identifying inflammatory monocytes as key sentinels in a LPS-induced murine model of neuroinflammation. PMID:29255461

Low-dose lipopolysaccharide (LPS) inhibits aggressive and augments depressive behaviours in a chronic mild stress model in mice.

PubMed

Couch, Yvonne; Trofimov, Alexander; Markova, Natalyia; Nikolenko, Vladimir; Steinbusch, Harry W; Chekhonin, Vladimir; Schroeter, Careen; Lesch, Klaus-Peter; Anthony, Daniel C; Strekalova, Tatyana

2016-05-16

Aggression, hyperactivity, impulsivity, helplessness and anhedonia are all signs of depressive-like disorders in humans and are often reported to be present in animal models of depression induced by stress or by inflammatory challenges. However, chronic mild stress (CMS) and clinically silent inflammation, during the recovery period after an infection, for example, are often coincident, but comparison of the behavioural and molecular changes that underpin CMS vs a mild inflammatory challenge and impact of the combined challenge is largely unexplored. Here, we examined whether stress-induced behavioural and molecular responses are analogous to lipopolysaccharide (LPS)-induced behavioural and molecular effects and whether their combination is adaptive or maladaptive. Changes in measures of hedonic sensitivity, helplessness, aggression, impulsivity and CNS and systemic cytokine and 5-HT-system-related gene expression were investigated in C57BL/6J male mice exposed to chronic stress alone, low-dose LPS alone or a combination of LPS and stress. When combined with a low dose of LPS, chronic stress resulted in an enhanced depressive-like phenotype but significantly reduced manifestations of aggression and hyperactivity. At the molecular level, LPS was a strong inducer of TNFα, IL-1β and region-specific 5-HT2A mRNA expression in the brain. There was also increased serum corticosterone as well as increased TNFα expression in the liver. Stress did not induce comparable levels of cytokine expression to an LPS challenge, but the combination of stress with LPS reduced the stress-induced changes in 5-HT genes and the LPS-induced elevated IL-1β levels. It is evident that when administered independently, both stress and LPS challenges induced distinct molecular and behavioural changes. However, at a time when LPS alone does not induce any overt behavioural changes per se, the combination with stress exacerbates depressive and inhibits aggressive behaviours.

Arctigenin ameliorates inflammation in vitro and in vivo by inhibiting the PI3K/AKT pathway and polarizing M1 macrophages to M2-like macrophages.

PubMed

Hyam, Supriya R; Lee, In-Ah; Gu, Wan; Kim, Kyung-Ah; Jeong, Jin-Ju; Jang, Se-Eun; Han, Myung Joo; Kim, Dong-Hyun

2013-05-15

Seeds of Arctium lappa, containing arctigenin and its glycoside arctiin as main constituents, have been used as a diuretic, anti-inflammatory and detoxifying agent in Chinese traditional medicine. In our preliminary study, arctigenin inhibited IKKβ and NF-κB activation in peptidoglycan (PGN)- or lipopolysaccharide (LPS)-induced peritoneal macrophages. To understand the anti-inflammatory effect of arctigenin, we investigated its anti-inflammatory effect in LPS-stimulated peritoneal macrophages and on LPS-induced systemic inflammation as well as 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in mice. Arctigenin inhibited LPS-increased IL-1β, IL-6 and TNF-α expression in LPS-stimulated peritoneal macrophages, but increased LPS-reduced IL-10 and CD204 expression. Arctigenin inhibited LPS-induced PI3K, AKT and IKKβ phosphorylation, but did not suppress LPS-induced IRAK-1 phosphorylation. However, arctigenin did not inhibit NF-κB activation in LPS-stimulated PI3K siRNA-treated peritoneal macrophages. Arctigenin suppressed the binding of p-PI3K antibody and the nucleus translocation of NF-κB p65 in LPS-stimulated peritoneal macrophages. Arctigenin suppressed blood IL-1β and TNF-α level in mice systemically inflamed by intraperitoneal injection of LPS. Arctigenin also inhibited colon shortening, macroscopic scores and myeloperoxidase activity in TNBS-induced colitic mice. Arctigenin inhibited TNBS-induced IL-1β, TNF-α and IL-6 expression, as well as PI3K, AKT and IKKβ phosphorylation and NF-κB activation in mice, but increased IL-10 and CD204 expression. However, it did not affect IRAK-1 phosphorylation. Based on these findings, arctigenin may ameliorate inflammatory diseases, such as colitis, by inhibiting PI3K and polarizing M1 macrophages to M2-like macrophages. Copyright © 2013 Elsevier B.V. All rights reserved.

Membrane insertion for the detection of lipopolysaccharides: Exploring the dynamics of amphiphile-in-lipid assays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stromberg, Loreen R.; Hengartner, Nicolas W.; Swingle, Kirstie L.

Shiga toxin-producing Escherichia coli is an important cause of foodborne illness, with cases attributable to beef, fresh produce and other sources. Many serotypes of the pathogen cause disease, and differentiating one serotype from another requires specific identification of the O antigen located on the lipopolysaccharide (LPS) molecule. The amphiphilic structure of LPS poses a challenge when using classical detection methods, which do not take into account its lipoglycan biochemistry. Typically, detection of LPS requires heat or chemical treatment of samples and relies on bioactivity assays for the conserved lipid A portion of the molecule. Our goal was to develop assaysmore » to facilitate the direct and discriminative detection of the entire LPS molecule and its O antigen in complex matrices using minimal sample processing. To perform serogroup identification of LPS, we used a method called membrane insertion on a waveguide biosensor, and tested three serogroups of LPS. The membrane insertion technique allows for the hydrophobic association of LPS with a lipid bilayer, where the exposed O antigen can be targeted for specific detection. Samples of beef lysate were spiked with LPS to perform O antigen specific detection of LPS from E. coli O157. To validate assay performance, we evaluated the biophysical interactions of LPS with lipid bilayers both in- and outside of a flow cell using fluorescence microscopy and fluorescently doped lipids. Our results indicate that membrane insertion allows for the qualitative and reliable identification of amphiphilic LPS in complex samples like beef homogenates. In addition, we also demonstrated that LPS-induced hole formation does not occur under the conditions of the membrane insertion assays. Together, these findings describe for the first time the serogroup-specific detection of amphiphilic LPS in complex samples using a membrane insertion assay, and highlight the importance of LPS molecular conformations in detection architectures.« less

Membrane insertion for the detection of lipopolysaccharides: Exploring the dynamics of amphiphile-in-lipid assays

DOE PAGES

Stromberg, Loreen R.; Hengartner, Nicolas W.; Swingle, Kirstie L.; ...

2016-05-26

Shiga toxin-producing Escherichia coli is an important cause of foodborne illness, with cases attributable to beef, fresh produce and other sources. Many serotypes of the pathogen cause disease, and differentiating one serotype from another requires specific identification of the O antigen located on the lipopolysaccharide (LPS) molecule. The amphiphilic structure of LPS poses a challenge when using classical detection methods, which do not take into account its lipoglycan biochemistry. Typically, detection of LPS requires heat or chemical treatment of samples and relies on bioactivity assays for the conserved lipid A portion of the molecule. Our goal was to develop assaysmore » to facilitate the direct and discriminative detection of the entire LPS molecule and its O antigen in complex matrices using minimal sample processing. To perform serogroup identification of LPS, we used a method called membrane insertion on a waveguide biosensor, and tested three serogroups of LPS. The membrane insertion technique allows for the hydrophobic association of LPS with a lipid bilayer, where the exposed O antigen can be targeted for specific detection. Samples of beef lysate were spiked with LPS to perform O antigen specific detection of LPS from E. coli O157. To validate assay performance, we evaluated the biophysical interactions of LPS with lipid bilayers both in- and outside of a flow cell using fluorescence microscopy and fluorescently doped lipids. Our results indicate that membrane insertion allows for the qualitative and reliable identification of amphiphilic LPS in complex samples like beef homogenates. In addition, we also demonstrated that LPS-induced hole formation does not occur under the conditions of the membrane insertion assays. Together, these findings describe for the first time the serogroup-specific detection of amphiphilic LPS in complex samples using a membrane insertion assay, and highlight the importance of LPS molecular conformations in detection architectures.« less

Local and systemic response to intramammary lipopolysaccharide challenge during long-term manipulated plasma glucose and insulin concentrations in dairy cows.

PubMed

Vernay, M C M B; Wellnitz, O; Kreipe, L; van Dorland, H A; Bruckmaier, R M

2012-05-01

The metabolic load during periods of high milk production in dairy cows causes a variety of changes of metabolite blood concentrations including dramatically decreased glucose levels. These changes supposedly impair the immune system. The goal of this study was, therefore, to evaluate adaptations of the cow's immune system in response to an intramammary lipopolysaccharide (LPS) stimulation during a 3-d modification of plasma glucose and insulin induced by different clamp infusions. Seventeen midlactating dairy cows received a hypoglycemic hyperinsulinemic clamp induced by insulin infusion (HypoG; n=5), a euglycemic hyperinsulinemic clamp induced by insulin and glucose infusion (EuG; n=6), or infusion of saline solution (NaCl; n=6) for 56 h. At 48 h of infusion, 2 udder quarters were challenged with 200 μg of Escherichia coli LPS. At 48 h of infusion (immediately before LPS challenge), tumor necrosis factor α, lactoferrin, and serum amyloid A (SAA) mRNA abundance was increased in HypoG and Il-1β mRNA abundance was decreased in EuG. After LPS challenge, plasma glucose concentration did not decrease, although plasma insulin increased simultaneously in all groups either due to enhanced endogenous release (NaCl) or due to increased insulin infusion rate (HypoG; EuG). Plasma cortisol, rectal temperatures, and milk somatic cell count of challenged quarters increased, whereas plasma nonesterified fatty acid concentrations were similarly decreased across treatments. In mammary biopsies, increased mRNA expression of tumor necrosis factor α, IL-1β, IL-8, and IL-10, and SAA were observed in LPS-treated quarters of all groups, with a more pronounced increase in IL-1β, IL-10, and SAA expression in EuG. Nuclear factor-κB mRNA expression was upregulated in NaCl and EuG but not in HypoG in response to LPS. Lactoferrin, toll-like receptor 4, and cyclooxygenase-2 mRNA expression was increased in LPS-treated quarters of EuG only, and 5-lipoxygenase mRNA expression was decreased in LPS-treated quarters only in treatments HypoG and NaCl. In conclusion, intramammary LPS induces local and systemic inflammatory responses, as well as systemic insulin resistance. The observed treatment differences of the mammary mRNA expression of several immune parameters both before and after LPS challenge indicate a direct influence of changed glucose and insulin concentrations during the course of lactation on the immune defense against mastitis pathogens. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Ordering kinetics in the long-period superlattice alloy Cu0.79 Pd0.21

NASA Astrophysics Data System (ADS)

Wang, X.; Mainville, J.; Ludwig, K.; Flament, X.; Finel, A.; Caudron, R.

2005-07-01

The kinetics of long-period superlattice (LPS) formation from the disordered state has been examined in a Cu0.79Pd0.21 alloy that exhibits a one-dimensional LPS ordered state. Time-resolved x-ray scattering shows that, following a rapid temperature quench from the disordered state into the LPS region of the phase diagram, the satellite peaks initially grow more quickly than do the central integer-order superlattice peaks. During this process, the satellite peak position, which is inversely related to the average modulation wavelength 2M , initially decreases rapidly, then reaches a minimum and relaxes slowly back toward its new equilibrium position. In the later stages of the LPS formation process, the satellite and central integer-order superlattice peaks narrow in a manner consistent with t1/2 domain coarsening. A simple stochastic model of the partially ordered structure was developed to better understand the relationships between peak widths.

Acute intraperitoneal lipopolysaccharide influences the immune system in the absence of gut dysbiosis.

PubMed

Sylvia, Kristyn E; Demas, Gregory E

2018-03-01

There is bidirectional communication between the immune system and the gut microbiome, however the precise mechanisms regulating this crosstalk are not well understood. Microbial-associated molecular patterns (MAMPs) within the gut, including lipopolysaccharide (LPS) that produces a quick and robust activation of the immune system, may be one way by which these interactions occur. Endogenous levels of LPS in the gut are low enough that they do not usually cause disease, although, in times of increased LPS loads, they may be capable of increasing vulnerability of the gut to pathogenic bacteria. Furthermore, chronic, low-grade inflammation can have lasting effects on the gut, but the effects of acute inflammation on gut communities have not been thoroughly assessed. In this study, we first investigated whether a single modest dose of LPS administered to adult male and female Siberian hamsters (Phodopus sungorus) activated the immune system by measuring levels of circulating cortisol and the proinflammatory cytokine TNF-α in the liver compared with saline-treated animals. We then investigated whether this same acute dose of LPS altered the microbiome 48 h after treatment. We found that, although LPS increased cortisol and liver cytokine levels, and produced changes in food intake and body mass in both sexes, immunological changes were independent of gut dysbiosis 48 h after LPS injection. These data suggest that an acute immune activation may not be capable of altering the gut microbiome in healthy individuals. It is likely, however, that this type of immune challenge may have other physiological impacts on the gut's vulnerability, and future studies will investigate these relationships further. © 2018 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

Effects of a bacterial lipopolysaccharide on the reproductive functions of rabbit does.

PubMed

Brecchia, G; Menchetti, L; Cardinali, R; Castellini, C; Polisca, A; Zerani, M; Maranesi, M; Boiti, C

2014-06-30

Systemic and local infections and inflammations are known to cause infertility in humans and animals. However, the mechanisms by which infection/inflammation induces infertility are only partially known. The objectives of this study were: (i) to provide models of systemic (acute) and local (sub-acute) inflammation by intra-peritoneal injection or intra-cervical deposition of lipopolysaccharide (LPS) in the rabbit and (ii) to assess their effects on uterine tissues and sperm transport in the genital tract of rabbit does. Intra-peritoneal administration of different doses of LPS induced systemic effects such as fever, anorexia and changes in white blood cells (WBC) count. In our study, LPS inoculation (100μg/kg) produced an inflammation-like status that lasted for about 3 days, with minimal distress for the animals. Intra-peritoneal administration of LPS 60h before artificial insemination induced a rapid increase of IL-1β concentrations. The intra-cervical inoculation of LPS did not show any systemic effects, as confirmed by the lack of changes in body temperature, feed intake and WBC count. Histological examination of uterine tissues showed an endometritis-like inflammation status in LPS-treated does, more severe in those inoculated intra-cervically. The number of spermatozoa recovered from uterine horns and oviducts of intra-cervically treated does was less than that retrieved from intra-peritoneally treated animals and controls. These results suggest (i) that sub-acute or acute inflammation may cause infertility by compromising the uterine environment and/or impairing sperm transport and (ii) that the LPS-induced -infection/inflammation experimental model is useful for studying the mechanisms involved in reproductive dysfunctions in the rabbit. Copyright © 2014 Elsevier B.V. All rights reserved.

Increase in hypothalamic AMPK phosphorylation induced by prolonged exposure to LPS involves ghrelin and CB1R signaling.

PubMed

Rivas, Priscila M S; Vechiato, Fernanda M V; Borges, Beatriz C; Rorato, Rodrigo; Antunes-Rodrigues, Jose; Elias, Lucila L K

2017-07-01

Acute administration of lipopolysaccharide (LPS) from Gram-negative bacteria induces hypophagia. However, the repeated administration of LPS leads to desensitization of hypophagia, which is associated with increased hypothalamic p-AMPK expression. Because ghrelin and endocannabinoids modulate AMPK activity in the hypothalamus, we hypothesized that these neuromodulators play a role in the reversal of tolerance to hypophagia in rats under long-term exposure to LPS. Male Wistar rats were treated with single (1 LPS, 100μg/kg body weight, ip) or repeated injections of LPS over 6days (6 LPS). Food intake was reduced in the 1 LPS, but not in the 6 LPS group. 6 LPS rats showed an increased serum concentration of acylated ghrelin and reduced ghrelin receptor mRNA expression in the hypothalamus. Ghrelin injection (40μg/kg body weight, ip) increased food intake, body weight gain, p-AMPK hypothalamic expression, neuropeptide Y (NPY) and Agouti related peptide (AgRP) mRNA expression in control animals (Saline). However, in 6 LPS rats, ghrelin did not alter these parameters. Central administration of a CB1R antagonist (AM251, 200ng/μl in 5μl/rat) induced hypophagia in 6 LPS animals, suggesting that the endocannabinoid system contributes to preserved food intake during LPS tolerance. In the presence of AM251, the ability of ghrelin to phosphorylate AMPK in the hypothalamus of 6 LPS group was restored, but not its orexigenic effect. Our data highlight that the orexigenic effects of ghrelin require CB1R signaling downstream of AMPK activation. Moreover, CB1R-mediated pathways contribute to the absence of hypophagia during repeated exposure to endotoxin. Copyright © 2017 Elsevier Inc. All rights reserved.

Lipopolysaccharides of Rhizobium etli strain G12 act in potato roots as an inducing agent of systemic resistance to infection by the cyst nematode Globodera pallida.

PubMed

Reitz, M; Rudolph, K; Schröder, I; Hoffmann-Hergarten, S; Hallmann, J; Sikora, R A

2000-08-01

Recent studies have shown that living and heat-killed cells of the rhizobacterium Rhizobium etli strain G12 induce in potato roots systemic resistance to infection by the potato cyst nematode Globodera pallida. To better understand the mechanisms of induced resistance, we focused on identifying the inducing agent. Since heat-stable bacterial surface carbohydrates such as exopolysaccharides (EPS) and lipopolysaccharides (LPS) are essential for recognition in the symbiotic interaction between Rhizobium and legumes, their role in the R. etli-potato interaction was studied. EPS and LPS were extracted from bacterial cultures, applied to potato roots, and tested for activity as an inducer of plant resistance to the plant-parasitic nematode. Whereas EPS did not affect G. pallida infection, LPS reduced nematode infection significantly in concentrations as low as 1 and 0.1 mg ml(-1). Split-root experiments, guaranteeing a spatial separation of inducing agent and challenging pathogen, showed that soil treatments of one half of the root system with LPS resulted in a highly significant (up to 37%) systemic induced reduction of G. pallida infection of potato roots in the other half. The results clearly showed that LPS of R. etli G12 act as the inducing agent of systemic resistance in potato roots.

Protective effect of vitamin E in an animal model of LPS-induced inflammation.

PubMed

Mayorga, M; Iborra, A; Estany, S; Martínez, P

2004-12-01

Many sterility outcomes may be associated to the presence of an inflammatory response that would lead to an inability of the endometrium to support implantation and maintain viable embryos. We have established an animal model of inflammation in which the systemic administration of lipopolysaccharyde (LPS) results in a low embryo implantation rate. The purpose of this work was to investigate the effect of the inflammatory agent LPS on embryo viability and to verify the ability of vitamin E to modulate the inflammatory effect of LPS on embryo viability. For pre-implantation studies B6CBAF1 mice, which were intraperitoneally inoculated with LPS (4-10 mg/kg), were used. Mice were also treated with vitamin E (4-10 mg/kg) before or after LPS injection. Embryos were obtained from the oviduct after each treatment. The LPS produces a decrease in the number of pre-implantational embryos in a concentration dependent manner. The LPS effect can be partially reversed or prevented by vitamin E. Preliminary results show that inflammatory cytokines are secreted by intraperitoneal macrophages in LPS treated mice. Our results demonstrate the ability of vitamin E to avoid an inflammatory environment and to allow viability of embryos. (c) Blackwell Munksgaard, 2004

Adsorption of endotoxins on Ca2+ -iminodiacetic acid by metal ion affinity chromatography.

PubMed

Lopes, André Moreni; Romeu, Jorge Sánchez; Meireles, Rolando Páez; Perera, Gabriel Marquez; Morales, Rolando Perdomo; Pessoa, Adalberto; Cárdenas, Lourdes Zumalacárregui

2012-11-01

Endotoxins (also known as lipopolysaccharides (LPS)) are undesirable by-products of recombinant proteins, purified from Escherichia coli. LPS can be considered stable under a wide range of temperature and pH, making their removal one of the most difficult tasks in downstream processes during protein purification. The inherent toxicity of LPS makes their removal an important step for the application of these proteins in several biological assays and for a safe parenteral administration. Immobilized metal affinity chromatography (IMAC) enables the affinity interactions between the metal ions (immobilized on the support through the chelating compound) and the target molecules, thus enabling high-efficiency separation of the target molecules from other components present in a mixture. Affinity chromatography is applied with Ca2+ -iminodiacetic acid (IDA) to remove most of the LPS contaminants from the end product (more than 90%). In this study, the adsorption of LPS on an IDA-Ca2+ was investigated. The adsorption Freundlich isotherm of LPS-IDA-Ca2+ provides a theoretical basis for LPS removal. It was found that LPS is bound mainly by interactions between the phosphate group in LPS and Ca2+ ligands on the beads. The factors such as pH (4.0 or 5.5) and ionic strength (1.0 mol/L) are essential to obtain effective removal of LPS for contaminant levels between endotoxin' concentration values less than 100 EU/mL and 100 000 EU/mL. This new protocol represents a substantial advantage in time, effort, and production costs.

Histone Deacetylase Inhibitor Trichostatin A Ameliorated Endotoxin-Induced Neuroinflammation and Cognitive Dysfunction

PubMed Central

Chen, Yeong-Chang; Wei, Tsui-Shan; Sun, Ding-Ping; Wang, Jhi-Joung; Yeh, Ching-Hua

2015-01-01

Excessive production of cytokines by microglia may cause cognitive dysfunction and long-lasting behavioral changes. Activating the peripheral innate immune system stimulates cytokine secretion in the central nervous system, which modulates cognitive function. Histone deacetylases (HDACs) modulate cytokine synthesis and release. Trichostatin A (TSA), an HDAC inhibitor, is documented to be anti-inflammatory and neuroprotective. We investigated whether TSA reduces lipopolysaccharide- (LPS-) induced neuroinflammation and cognitive dysfunction. ICR mice were first intraperitoneally (i.p.) injected with vehicle or TSA (0.3 mg/kg). One hour later, they were injected (i.p.) with saline or Escherichia coli LPS (1 mg/kg). We analyzed the food and water intake, body weight loss, and sucrose preference of the injected mice and then determined the microglia activation and inflammatory cytokine expression in the brains of LPS-treated mice and LPS-treated BV-2 microglial cells. In the TSA-pretreated mice, microglial activation was lower, anhedonia did not occur, and LPS-induced cognitive dysfunction (anorexia, weight loss, and social withdrawal) was attenuated. Moreover, mRNA expression of HDAC2, HDAC5, indoleamine 2,3-dioxygenase (IDO), TNF-α, MCP-1, and IL-1β in the brain of LPS-challenged mice and in the LPS-treated BV-2 microglial cells was lower. TSA diminished LPS-induced inflammatory responses in the mouse brain and modulated the cytokine-associated changes in cognitive function, which might be specifically related to reducing HDAC2 and HDAC5 expression. PMID:26273133

Mechanisms of fever production and lysis: lessons from experimental LPS fever.

PubMed

Roth, Joachim; Blatteis, Clark M

2014-10-01

Fever is a cardinal symptom of infectious or inflammatory insults, but it can also arise from noninfectious causes. The fever-inducing agent that has been used most frequently in experimental studies designed to characterize the physiological, immunological and neuroendocrine processes and to identify the neuronal circuits that underlie the manifestation of the febrile response is lipopolysaccharide (LPS). Our knowledge of the mechanisms of fever production and lysis is largely based on this model. Fever is usually initiated in the periphery of the challenged host by the immediate activation of the innate immune system by LPS, specifically of the complement (C) cascade and Toll-like receptors. The first results in the immediate generation of the C component C5a and the subsequent rapid production of prostaglandin E2 (PGE2). The second, occurring after some delay, induces the further production of PGE2 by induction of its synthesizing enzymes and transcription and translation of proinflammatory cytokines. The Kupffer cells (Kc) of the liver seem to be essential for these initial processes. The subsequent transfer of the pyrogenic message from the periphery to the brain is achieved by neuronal and humoral mechanisms. These pathways subserve the genesis of early (neuronal signals) and late (humoral signals) phases of the characteristically biphasic febrile response to LPS. During the course of fever, counterinflammatory factors, "endogenous antipyretics," are elaborated peripherally and centrally to limit fever in strength and duration. The multiple interacting pro- and antipyretic signals and their mechanistic effects that underlie endotoxic fever are the subjects of this review.

Identification of Residues in the Lipopolysaccharide ABC Transporter That Coordinate ATPase Activity with Extractor Function.

PubMed

Simpson, Brent W; Owens, Tristan W; Orabella, Matthew J; Davis, Rebecca M; May, Janine M; Trauger, Sunia A; Kahne, Daniel; Ruiz, Natividad

2016-10-18

The surface of most Gram-negative bacteria is covered with lipopolysaccharide (LPS), creating a permeability barrier against toxic molecules, including many antimicrobials. To assemble LPS on their surface, Gram-negative bacteria must extract newly synthesized LPS from the inner membrane, transport it across the aqueous periplasm, and translocate it across the outer membrane. The LptA to -G proteins assemble into a transenvelope complex that transports LPS from the inner membrane to the cell surface. The Lpt system powers LPS transport from the inner membrane by using a poorly characterized ATP-binding cassette system composed of the ATPase LptB and the transmembrane domains LptFG. Here, we characterize a cluster of residues in the groove region of LptB that is important for controlling LPS transport. We also provide the first functional characterization of LptFG and identify their coupling helices that interact with the LptB groove. Substitutions at conserved residues in these coupling helices compromise both the assembly and function of the LptB 2 FG complex. Defects in LPS transport conferred by alterations in the LptFG coupling helices can be rescued by changing a residue in LptB that is adjacent to functionally important residues in the groove region. This suppression is achieved by increasing the ATPase activity of the LptB 2 FG complex. Taken together, these data identify a specific binding site in LptB for the coupling helices of LptFG that is responsible for coupling of ATP hydrolysis by LptB with LptFG function to achieve LPS extraction. Lipopolysaccharide (LPS) is synthesized at the cytoplasmic membrane of Gram-negative bacteria and transported across several compartments to the cell surface, where it forms a barrier that protects these organisms from antibiotics. The LptB 2 FG proteins form an ATP-binding cassette (ABC) transporter that uses energy from ATP hydrolysis in the cytoplasm to facilitate extraction of LPS from the outer face of the cytoplasmic membrane prior to transport to the cell surface. How ATP hydrolysis is coupled with LPS release from the membrane is not understood. We have identified residues at the interface between the ATPase and the transmembrane domains of this heteromeric ABC complex that are important for LPS transport, some of which coordinate ATPase activity with LPS release. Copyright © 2016 Simpson et al.

CD14 is a key mediator of both lysophosphatidic acid and lipopolysaccharide induction of foam cell formation.

PubMed

An, Dong; Hao, Feng; Zhang, Fuqiang; Kong, Wei; Chun, Jerold; Xu, Xuemin; Cui, Mei-Zhen

2017-09-01

Macrophage uptake of oxidized low-density lipoprotein (oxLDL) plays an important role in foam cell formation and the pathogenesis of atherosclerosis. We report here that lysophosphatidic acid (LPA) enhances lipopolysaccharide (LPS)-induced oxLDL uptake in macrophages. Our data revealed that both LPA and LPS highly induce the CD14 expression at messenger RNA and protein levels in macrophages. The role of CD14, one component of the LPS receptor cluster, in LPA-induced biological functions has been unknown. We took several steps to examine the role of CD14 in LPA signaling pathways. Knockdown of CD14 expression nearly completely blocked LPA/LPS-induced oxLDL uptake in macrophages, demonstrating for the first time that CD14 is a key mediator responsible for both LPA- and LPS-induced oxLDL uptake/foam cell formation. To determine the molecular mechanism mediating CD14 function, we demonstrated that both LPA and LPS significantly induce the expression of scavenger receptor class A type I (SR-AI), which has been implicated in lipid uptake process, and depletion of CD14 levels blocked LPA/LPS-induced SR-AI expression. We further showed that the SR-AI-specific antibody, which quenches SR-AI function, blocked LPA- and LPS-induced foam cell formation. Thus, SR-AI is the downstream mediator of CD14 in regulating LPA-, LPS-, and LPA/LPS-induced foam cell formation. Taken together, our results provide the first experimental evidence that CD14 is a novel connecting molecule linking both LPA and LPS pathways and is a key mediator responsible for LPA/LPS-induced foam cell formation. The LPA/LPS-CD14-SR-AI nexus might be the new convergent pathway, contributing to the worsening of atherosclerosis. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Lipopolysaccharide inhibits colonic biotin uptake via interference with membrane expression of its transporter: a role for a casein kinase 2-mediated pathway.

PubMed

Lakhan, Ram; Said, Hamid M

2017-04-01

Biotin (vitamin B7), an essential micronutrient for normal cellular functions, is obtained from both dietary sources as well as gut microbiota. Absorption of biotin in both the small and large intestine is via a carrier-mediated process that involves the sodium-dependent multivitamin transporter (SMVT). Although different physiological and molecular aspects of intestinal biotin uptake have been delineated, nothing is known about the effect of LPS on the process. We addressed this issue using in vitro (human colonic epithelial NCM460 cells) and in vivo (mice) models of LPS exposure. Treating NCM460 cells with LPS was found to lead to a significant inhibition in carrier-mediated biotin uptake. Similarly, administration of LPS to mice led to a significant inhibition in biotin uptake by native colonic tissue. Although no changes in total cellular SMVT protein and mRNA levels were observed, LPS caused a decrease in the fraction of SMVT expressed at the cell surface. A role for casein kinase 2 (CK2) (whose activity was also inhibited by LPS) in mediating the endotoxin effects on biotin uptake and on membrane expression of SMVT was suggested by findings that specific inhibitors of CK2, as well as mutating the putative CK2 phosphorylation site (Thr 78 Ala) in the SMVT protein, led to inhibition in biotin uptake and membrane expression of SMVT. This study shows for the first time that LPS inhibits colonic biotin uptake via decreasing membrane expression of its transporter and that these effects likely involve a CK2-mediated pathway.

Lipopolysaccharide inhibits colonic biotin uptake via interference with membrane expression of its transporter: a role for a casein kinase 2-mediated pathway

PubMed Central

Lakhan, Ram

2017-01-01

Biotin (vitamin B7), an essential micronutrient for normal cellular functions, is obtained from both dietary sources as well as gut microbiota. Absorption of biotin in both the small and large intestine is via a carrier-mediated process that involves the sodium-dependent multivitamin transporter (SMVT). Although different physiological and molecular aspects of intestinal biotin uptake have been delineated, nothing is known about the effect of LPS on the process. We addressed this issue using in vitro (human colonic epithelial NCM460 cells) and in vivo (mice) models of LPS exposure. Treating NCM460 cells with LPS was found to lead to a significant inhibition in carrier-mediated biotin uptake. Similarly, administration of LPS to mice led to a significant inhibition in biotin uptake by native colonic tissue. Although no changes in total cellular SMVT protein and mRNA levels were observed, LPS caused a decrease in the fraction of SMVT expressed at the cell surface. A role for casein kinase 2 (CK2) (whose activity was also inhibited by LPS) in mediating the endotoxin effects on biotin uptake and on membrane expression of SMVT was suggested by findings that specific inhibitors of CK2, as well as mutating the putative CK2 phosphorylation site (Thr78Ala) in the SMVT protein, led to inhibition in biotin uptake and membrane expression of SMVT. This study shows for the first time that LPS inhibits colonic biotin uptake via decreasing membrane expression of its transporter and that these effects likely involve a CK2-mediated pathway. PMID:28052864

Energetics of Endotoxin Recognition in the Toll-Like Receptor 4 Innate Immune Response.

PubMed

Paramo, Teresa; Tomasio, Susana M; Irvine, Kate L; Bryant, Clare E; Bond, Peter J

2015-12-09

Bacterial outer membrane lipopolysaccharide (LPS) potently stimulates the mammalian innate immune system, and can lead to sepsis, the primary cause of death from infections. LPS is sensed by Toll-like receptor 4 (TLR4) in complex with its lipid-binding coreceptor MD-2, but subtle structural variations in LPS can profoundly modulate the response. To better understand the mechanism of LPS-induced stimulation and bacterial evasion, we have calculated the binding affinity to MD-2 of agonistic and antagonistic LPS variants including lipid A, lipid IVa, and synthetic antagonist Eritoran, and provide evidence that the coreceptor is a molecular switch that undergoes ligand-induced conformational changes to appropriately activate or inhibit the receptor complex. The plasticity of the coreceptor binding cavity is shown to be essential for distinguishing between ligands, whilst similar calculations for a model bacterial LPS bilayer reveal the "membrane-like" nature of the protein cavity. The ability to predict the activity of LPS variants should facilitate the rational design of TLR4 therapeutics.

Energetics of Endotoxin Recognition in the Toll-Like Receptor 4 Innate Immune Response

PubMed Central

Paramo, Teresa; Tomasio, Susana M.; Irvine, Kate L.; Bryant, Clare E.; Bond, Peter J.

2015-01-01

Bacterial outer membrane lipopolysaccharide (LPS) potently stimulates the mammalian innate immune system, and can lead to sepsis, the primary cause of death from infections. LPS is sensed by Toll-like receptor 4 (TLR4) in complex with its lipid-binding coreceptor MD-2, but subtle structural variations in LPS can profoundly modulate the response. To better understand the mechanism of LPS-induced stimulation and bacterial evasion, we have calculated the binding affinity to MD-2 of agonistic and antagonistic LPS variants including lipid A, lipid IVa, and synthetic antagonist Eritoran, and provide evidence that the coreceptor is a molecular switch that undergoes ligand-induced conformational changes to appropriately activate or inhibit the receptor complex. The plasticity of the coreceptor binding cavity is shown to be essential for distinguishing between ligands, whilst similar calculations for a model bacterial LPS bilayer reveal the “membrane-like” nature of the protein cavity. The ability to predict the activity of LPS variants should facilitate the rational design of TLR4 therapeutics. PMID:26647780

Joint study of lipopolysaccharide suspensions with thermal lensing and optoacoustic methods

NASA Astrophysics Data System (ADS)

Orlova, Nataliya V.; Brusnichkin, Anton V.; Proskurnin, Mikhail A.; Fokin, Andrey V.; Ovchinnikov, Oleg B.; Egerev, Sergey V.

2004-07-01

Pyrogens being introduced intravenously increase body temperature that leads to hazardous consequences and even to lethal outcome. One of the widespread pyrogen systems is presented by suspensions composed of bacterial endotoxins (or lypopolysaccharides, LPS). The aim of the work is to compare experimentally two methods for the determination of LPS at the submicrogram level and below. Both methods suppose that the LPS suspension is irradiated by a laser pulse. The thermal lens (TL) method (microsecond to millisecond irradiation cycle) detects LPS by a direct pick-up of the transient thermal field. The optoacoustic (OA) method (nanosecond laser pulses) has a potential to use non-thermal constitutents of the LPS response and to provide some selectivity of LPS detection with respect to optically uniform contaminants in the sample. In experiments, the selectivity was enhanced by means of analytical reagents, methylene blue and Stains All dyes. It was shown that both methods are mutually complementary. Then, their detectability potential increases and reaches 10 ppb if there occur ion pairs of LPS and cationic dye.

Top Down Tandem Mass Spectrometric Analysis of a Chemically Modified Rough-Type Lipopolysaccharide Vaccine Candidate.

PubMed

Oyler, Benjamin L; Khan, Mohd M; Smith, Donald F; Harberts, Erin M; Kilgour, David P A; Ernst, Robert K; Cross, Alan S; Goodlett, David R

2018-06-01

Recent advances in lipopolysaccharide (LPS) biology have led to its use in drug discovery pipelines, including vaccine and vaccine adjuvant discovery. Desirable characteristics for LPS vaccine candidates include both the ability to produce a specific antibody titer in patients and a minimal host inflammatory response directed by the innate immune system. However, in-depth chemical characterization of most LPS extracts has not been performed; hence, biological activities of these extracts are unpredictable. Additionally, the most widely adopted workflow for LPS structure elucidation includes nonspecific chemical decomposition steps before analyses, making structures inferred and not necessarily biologically relevant. In this work, several different mass spectrometry workflows that have not been previously explored were employed to show proof-of-principle for top down LPS primary structure elucidation, specifically for a rough-type mutant (J5) E. coli-derived LPS component of a vaccine candidate. First, ion mobility filtered precursor ions were subjected to collision induced dissociation (CID) to define differences in native J5 LPS v. chemically detoxified J5 LPS (dLPS). Next, ultra-high mass resolving power, accurate mass spectrometry was employed for unequivocal precursor and product ion empirical formulae generation. Finally, MS 3 analyses in an ion trap instrument showed that previous knowledge about dissociation of LPS components can be used to reconstruct and sequence LPS in a top down fashion. A structural rationale is also explained for differential inflammatory dose-response curves, in vitro, when HEK-Blue hTLR4 cells were administered increasing concentrations of native J5 LPS v. dLPS, which will be useful in future drug discovery efforts. Graphical Abstract ᅟ.

Which one is more effective for the treatment of rat sepsis model: thalidomide or etanercept?

PubMed

Ilhan, N; Susam, S; Gul, H F; Bardas, R; Ilhan, N

2017-01-01

We aimed to investigate the protective effect of selected treatment agents on liver injury in lipopolysaccharide (LPS)-induced rat sepsis model. The sepsis includes complex inflammatory responses between a microbial pathogen and the host immune system, and leads to organ failure and also death. This study was performed with 29 male Wistar Albino rats. Rats were divided randomly into five groups: Sham group, LPS-treated sepsis group, LPS+thalidomide treated group, LPS+etanercept treated group and LPS+thalidomide+etanercept treated group, respectively. Liver tissue tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β) and interleukin 6 (IL-6) levels were determined by enzyme-linked immuno-sorbent assay (ELISA) method. The expression of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) was performed using western blot analysis. The levels of tissue TNF-α, IL-1β and IL-6 were found statistically significantly higher in sepsis group than in the sham group. TNF-α levels were found statistically significantly decreased in LPS+etanercept and LPS+thalidomide+etanercept treated groups when compared with LPS group (p < 0.05). For IL-1β and IL-6 levels a statistically significant decline was observed in the LPS+thalidomide and LPS+etanercept treated groups compared to the LPS group (p < 0.05). Expression of NF-κB protein in liver tissue was significantly elevated in the LPS group compared to sham group (p < 0.001). In treatment groups, a marked decrease was observed in NF-κB protein expression. The results of this investigation suggested that etanercept and thalidomide administration may have a beneficial effect on LPS-induced sepsis. So, the present study may have significant clinical relevance, but clinical trials are needed to confirm these results (Tab. 1, Fig. 1, Ref. 36).

Top Down Tandem Mass Spectrometric Analysis of a Chemically Modified Rough-Type Lipopolysaccharide Vaccine Candidate

NASA Astrophysics Data System (ADS)

Oyler, Benjamin L.; Khan, Mohd M.; Smith, Donald F.; Harberts, Erin M.; Kilgour, David P. A.; Ernst, Robert K.; Cross, Alan S.; Goodlett, David R.

2018-02-01

Recent advances in lipopolysaccharide (LPS) biology have led to its use in drug discovery pipelines, including vaccine and vaccine adjuvant discovery. Desirable characteristics for LPS vaccine candidates include both the ability to produce a specific antibody titer in patients and a minimal host inflammatory response directed by the innate immune system. However, in-depth chemical characterization of most LPS extracts has not been performed; hence, biological activities of these extracts are unpredictable. Additionally, the most widely adopted workflow for LPS structure elucidation includes nonspecific chemical decomposition steps before analyses, making structures inferred and not necessarily biologically relevant. In this work, several different mass spectrometry workflows that have not been previously explored were employed to show proof-of-principle for top down LPS primary structure elucidation, specifically for a rough-type mutant (J5) E. coli-derived LPS component of a vaccine candidate. First, ion mobility filtered precursor ions were subjected to collision induced dissociation (CID) to define differences in native J5 LPS v. chemically detoxified J5 LPS (dLPS). Next, ultra-high mass resolving power, accurate mass spectrometry was employed for unequivocal precursor and product ion empirical formulae generation. Finally, MS3 analyses in an ion trap instrument showed that previous knowledge about dissociation of LPS components can be used to reconstruct and sequence LPS in a top down fashion. A structural rationale is also explained for differential inflammatory dose-response curves, in vitro, when HEK-Blue hTLR4 cells were administered increasing concentrations of native J5 LPS v. dLPS, which will be useful in future drug discovery efforts. [Figure not available: see fulltext.

Lipopolysaccharide promotes lipid accumulation in human adventitial fibroblasts via TLR4-NF-κB pathway.

PubMed

Wang, Jun; Si, Yanfang; Wu, Chen; Sun, Lu; Ma, Yudong; Ge, Aili; Li, Baomin

2012-10-17

Atherosclerosis is a chronic degenerative disease of the arteries and is thought to be one of the most common causes of death globally. In recent years, the functions of adventitial fibroblasts in the development of atherosclerosis and tissue repair have gained increased interests. LPS can increase the morbidity and mortality of atherosclerosis-associated cardiovascular disease. Although LPS increases neointimal via TLR4 activation has been reported, how LPS augments atherogenesis through acting on adventitial fibroblasts is still unknown. Here we explored lipid deposition within adventitial fibroblasts mediated by lipopolysaccharide (LPS) to imitate inflammatory conditions. In our study, LPS enhanced lipid deposition by the up-regulated expression of adipose differentiation-related protein (ADRP) as the silencing of ADRP abrogated lipid deposition in LPS-activated adventitial fibroblasts. In addition, pre-treatment with anti-Toll-like receptor 4 (TLR4) antibody diminished the LPS-induced lipid deposition and ADRP expression. Moreover, LPS induced translocation of nuclear factor-κB (NF-κB), which could markedly up-regulate lipid deposition as pre-treatment with the NF-κB inhibitor, PDTC, significantly reduced lipid droplets. In addition, the lowering lipid accumulation was accompanied with the decreased ADRP expression. Furthermore, LPS-induced adventitial fibroblasts secreted more monocyte chemoattractant protein (MCP-1), compared with transforming growth factor-β1 (TGF-β1). Taken together, these results suggest that LPS promotes lipid accumulation via the up-regulation of ADRP expression through TLR4 activated downstream of NF-κB in adventitial fibroblasts. Increased levels of MCP-1 released from LPS-activated adventitial fibroblasts and lipid accumulation may accelerate monocytes recruitment and lipid-laden macrophage foam cells formation. Here, our study provides a new explanation as to how bacterial infection contributes to the pathological process of atherosclerosis.

Lipopolysaccharide promotes lipid accumulation in human adventitial fibroblasts via TLR4-NF-κB pathway

PubMed Central

2012-01-01

Background Atherosclerosis is a chronic degenerative disease of the arteries and is thought to be one of the most common causes of death globally. In recent years, the functions of adventitial fibroblasts in the development of atherosclerosis and tissue repair have gained increased interests. LPS can increase the morbidity and mortality of atherosclerosis-associated cardiovascular disease. Although LPS increases neointimal via TLR4 activation has been reported, how LPS augments atherogenesis through acting on adventitial fibroblasts is still unknown. Here we explored lipid deposition within adventitial fibroblasts mediated by lipopolysaccharide (LPS) to imitate inflammatory conditions. Results In our study, LPS enhanced lipid deposition by the up-regulated expression of adipose differentiation-related protein (ADRP) as the silencing of ADRP abrogated lipid deposition in LPS-activated adventitial fibroblasts. In addition, pre-treatment with anti-Toll-like receptor 4 (TLR4) antibody diminished the LPS-induced lipid deposition and ADRP expression. Moreover, LPS induced translocation of nuclear factor-κB (NF-κB), which could markedly up-regulate lipid deposition as pre-treatment with the NF-κB inhibitor, PDTC, significantly reduced lipid droplets. In addition, the lowering lipid accumulation was accompanied with the decreased ADRP expression. Furthermore, LPS-induced adventitial fibroblasts secreted more monocyte chemoattractant protein (MCP-1), compared with transforming growth factor-β1 (TGF-β1). Conclusions Taken together, these results suggest that LPS promotes lipid accumulation via the up-regulation of ADRP expression through TLR4 activated downstream of NF-κB in adventitial fibroblasts. Increased levels of MCP-1 released from LPS-activated adventitial fibroblasts and lipid accumulation may accelerate monocytes recruitment and lipid-laden macrophage foam cells formation. Here, our study provides a new explanation as to how bacterial infection contributes to the pathological process of atherosclerosis. PMID:23072373

Lipopolysaccharide can modify differentiation and immunomodulatory potential of periodontal ligament stem cells via ERK1,2 signaling.

PubMed

Kukolj, Tamara; Trivanović, Drenka; Djordjević, Ivana Okić; Mojsilović, Slavko; Krstić, Jelena; Obradović, Hristina; Janković, Srdja; Santibanez, Juan Francisco; Jauković, Aleksandra; Bugarski, Diana

2018-01-01

Lipopolysaccharide (LPS) is a pertinent deleterious factor in oral microenvironment for cells which are carriers of regenerative processes. The aim of this study was to investigate the emerging in vitro effects of LPS (Escherichia coli) on human periodontal ligament stem cell (PDLSC) functions and associated signaling pathways. We demonstrated that LPS did not affect immunophenotype, proliferation, viability, and cell cycle of PDLSCs. However, LPS modified lineage commitment of PDLSCs inhibiting osteogenesis by downregulating Runx2, ALP, and Ocn mRNA expression, while stimulating chondrogenesis and adipogenesis by upregulating Sox9 and PPARγ mRNA expression. LPS promoted myofibroblast-like phenotype of PDLSCs, since it significantly enhanced PDLSC contractility, as well as protein and/or gene expression of TGF-β, fibronectin (FN), α-SMA, and NG2. LPS also increased protein and gene expression levels of anti-inflammatory COX-2 and pro-inflammatory IL-6 molecules in PDLSCs. Inhibition of peripheral blood mononuclear cells (MNCs) transendothelial migration in presence of LPS-treated PDLSCs was accompanied by the reduction of CD29 expression within MNCs. However, LPS treatment did not change the inhibitory effect of PDLSCs on mitogen-stimulated proliferation of CD4 + and the ratio of CD4 + CD25 high /CD4 + CD25 low lymphocytes. LPS-treated PDLSCs did not change the frequency of CD34 + and CD45 + cells, but decreased the frequency of CD33 + and CD14 + myeloid cells within MNCs. Moreover, LPS treatment attenuated the stimulatory effect of PDLSCs on CFC activity of MNCs, predominantly the CFU-GM number. The results indicated that LPS-activated ERK1,2 was at least partly involved in the observed effects on PDLSC differentiation capacity, acquisition of myofibroblastic attributes, and changes of their immunomodulatory features. © 2017 Wiley Periodicals, Inc.

Sulforaphane suppresses LPS-induced inflammation in primary rat microglia.

PubMed

Brandenburg, Lars-Ove; Kipp, Markus; Lucius, Ralph; Pufe, Thomas; Wruck, Christoph J

2010-06-01

The aim of this study was to investigate the signal transduction pathways involved in sulforaphane (SF) mediated inhibition of the inflammatory response to lipopolysaccharide (LPS). Additionally, we investigated the effects of SF and LPS on the activity of Nrf2. Primary rat microglia and the murine microglia cell line BV2 were used. Cells were treated with LPS with or without SF. Cell viability was measured via WST-assay. Real-time RT-PCR was performed to analyze cytokine mRNA levels. The nitric oxide (NO) release was measured in LPS-stimulated microglia. The induction of various signal transduction pathways and Nrf2 was determined by Western blotting. NF-kappaB and AP-1 activation was measured by dual luciferase assay. We showed that SF attenuates the LPS-induced increase of IL-1beta, IL-6, and TNF-alpha expression in microglia. In addition, SF significantly decreases the NO in a concentration-dependent manner. SF inhibits LPS-stimulated ERK1/2 and JNK phosphorylation and thereby inhibits the LPS-induced activation of NF-kappaB- and activator protein-1 (AP-1). Moreover, SF and LPS together are able to induce Nrf2 activation. We showed that SF, and also LPS by itself, are able to activate the cell's defence against oxidative and electrophilic stress. We conclude that SF could be a candidate agent for anti-inflammatory treatment of the central nervous system.

Minocycline protects against lipopolysaccharide-induced cognitive impairment in mice.

PubMed

Hou, Yue; Xie, Guanbo; Liu, Xia; Li, Guoxun; Jia, Congcong; Xu, Jinghua; Wang, Bing

2016-03-01

The role of glial cells, especially microglia and astrocytes, in neuroinflammation and cognition has been studied intensively. Lipopolysaccharide (LPS), a commonly used inducer of neuroinflammation, can cause cognitive impairment. Minocycline is known to possess potent neuroprotective activity, but its effect on LPS-induced cognitive impairment is unknown. This study aims to investigate the effects of minocycline on LPS-induced cognitive impairment and glial cell activation in mice. Behavioral tests were conducted for cognitive function, immunohistochemistry for microglial and astrocyte response, and quantitative PCR for mRNA expression of proinflammatory cytokines. Minocycline significantly reversed the decreased spontaneous alternation induced by intrahippocampal administration of LPS in the Y-maze task. In the Morris water maze place navigation test, minocycline decreased the escape latency and distance traveled compared to LPS-treated mice. In the probe test, minocycline-treated mice spent more time in the target quadrant and crossed the platform area more frequently than animals in the LPS-treated group. Minocycline produced a significant decrease in the number of Iba-1- and GFAP-positive hippocampal cells compared to the LPS-treated group. Minocycline-treated mice had significantly reduced hippocampal TNF-α and IL-1β mRNA levels compared with LPS-treated animals. Minocycline caused a significant increase in hippocampal BDNF expression compared to the LPS-treated group. Minocycline can attenuate LPS-induced cognitive impairments in mice. This effect may be associated with its action to suppress the activation of microglia and astrocytes and to normalize BDNF expression. Since neuroinflammatory processes and cognitive impairments are implicated in neurodegenerative disorders, minocycline may be a promising candidate for treating such diseases.

A role for the endocannabinoid system in premature luteal regression and progesterone withdrawal in lipopolysaccharide-induced early pregnancy loss model.

PubMed

Schander, Julieta Aylen; Correa, Fernando; Bariani, María Victoria; Blanco, Julieta; Cymeryng, Cora; Jensen, Federico; Wolfson, Manuel Luis; Franchi, Ana María

2016-11-01

What is the role of the endocannabinoid system (eCS) in the alterations of the endocrine system in a murine model of lipopolysaccharide (LPS)-induced miscarriage? In 7-days pregnant wild type, but not cannabinoid receptor type 1 knockout (CB1-KO) mice, LPS increased COX-2 expression and prostaglandin F 2α (PGF 2α ) production in the uterus leading to lower expression of prolactin receptor in the ovary and a marked regression of corpora lutea (CL), suggesting that the eCS mediates the deleterious effects of LPS on reproductive events. Appropriate systemic progesterone levels are critical for a successful pregnancy outcome. Precocious loss of luteal progesterone (P4) secretion leads to miscarriage in rodents. We have previously shown that LPS administration to pregnant mice induces embryonic resorption accompanied by a dramatic decrease in systemic progesterone levels in a murine model of inflammatory miscarriage, with the eCS mediating these LPS-induced deleterious effects. CD1 wild-type (WT) and CB1-KO mice were randomly allocated to Vehicle (saline; i.p.) or LPS (0.5 μg/g body weight; i.p.) treated groups: (WT-Vehicle; WT-LPS; CB1-KO-Vehicle and CB1-KO-LPS). A single injection was given on day 7 of pregnancy and tissues (blood, ovary, uterus) were collected 6, 12, 24 and 48 h later. P4 and PGF2α plasma levels were determined by radioimmunoassay. Cyclooxygenase-2 (COX-2) mRNA (RT-PCR) and protein (Western blot) content in uterus was assayed. COX-2 and prolactin receptor (PrlR) mRNA levels in the ovary were assayed by RT-PCR. Tissue morphology of the CL was assessed by haematoxylin-eosin staining. Treatment of 7-day pregnant WT mice with LPS induced a P4 withdrawal (p < 0.05), increased in uterine COX-2 mRNA and protein expression (p < 0.05) as well as an increase in uterine PGF 2α production (p < 0.05). These changes were absent in LPS-treated 7-day pregnant CB1-KO mice. In ovarian tissues, LPS treatment to 7-day pregnant WT mice induced a downregulation of PrlR mRNA expression (p < 0.05) together with an increase in COX-2 mRNA expression (p < 0.05) and PGF 2α content (p < 0.05). These effects were absent in the CB1-KO mice. Collectively, our results suggest a role for the eCS mediating LPS-induced deleterious effects on reproductive tissues. An important caveat of this study is the endocrine differences between mice and humans during pregnancy (e.g. P4 is produced by the CL throughout pregnancy in mice, whereas this is not the case in humans), which limits the extrapolation of the results presented here. Our findings provide new insights in the role of the endocannabinoid system in the physiopathology of reproduction as well as the role of this endogenous system as a mediator of LPS deleterious effects on reproductive tissues. None. Dr Ana María Franchi was funded by Agencia Nacional para la Promoción Científica y Tecnológica (PICT 2010/0813 and PICT 2013/0097) and by Consejo Nacional de Investigaciones Científicas y Técnicas (PIP 2012/0061). The authors have no competing interests. © The Author 2016. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved.For Permissions, please email: journals.permissions@oup.com.

EFFECTS OF SYSTEMIC NEUTROPHIL DEPLETION ON LPS-INDUCED AIRWAY DISEASE

EPA Science Inventory

Effects of Systemic Neutrophil Depletion on LPS-induced Airway Disease
Jordan D. Savov, Stephen H. Gavett*, David M. Brass, Daniel L. Costa*, David A. Schwartz
Pulmonary and Critical Care Division, Dept of Medicine ? Duke University Medical Center
* National Health and E...

Signals generating anorexia during acute illness.

PubMed

Langhans, Wolfgang

2007-08-01

Anorexia is part of the body's acute-phase response to illness. Microbial products such as lipopolysaccharides (LPS), which are also commonly used to model acute illness, trigger the acute-phase response and cause anorexia mainly through pro-inflammatory cytokines. LPS stimulate cytokine production through the cell-surface structural molecule CD14 and toll-like receptor-4. Cytokines ultimately change neural activity in brain areas controlling food intake and energy balance. The blood-brain barrier endothelial cells (BBB EC) are an important site of cytokine action in this context. BBB EC and perivascular cells (microglia and macrophages) form a complex regulatory interface that modulates neuronal activity by the release of messengers (e.g. PG, NO) in response to peripheral challenges. Serotonergic neurons originating in the raphe nuclei and glucagon-like peptide-1-expressing neurons in the hindbrain may be among the targets of these messengers, because serotonin (5-HT), acting through the 5-HT2C receptor, and glucagon-like peptide-1 have recently emerged as neurochemical mediators of LPS anorexia. The central melanocortin system, which is a downstream target of serotonergic neurons, also appears to be involved in mediation of LPS anorexia. Interestingly, LPS also reduce orexin expression and the activity of orexin neurons in the lateral hypothalamic area of fasted mice. As the eating-stimulatory properties of orexin are apparently related to arousal, the inhibitory effect of LPS on orexin neurons might be involved in LPS-induced inactivity and anorexia. In summary, the immune signalling pathways of LPS-induced, and presumably acute illness-induced, anorexia converge on central neural signalling systems that control food intake and energy balance in healthy individuals.

Lipopolysaccharides do not alter metabolic disturbances in hippocampal slices of fetal guinea pigs after oxygen-glucose deprivation.

PubMed

Berger, R; Garnier, Y; Pfeiffer, D; Jensen, A

2000-10-01

The aim of the present study was to clarify whether endotoxins [lipopolysaccharides (LPS)] have a toxic effect on fetal brain tissue after cerebral ischemia, while excluding their effect on the cardiovascular system. Experiments were therefore performed on hippocampal slices prepared from mature fetal guinea pigs. In particular, we studied the influence of LPS on nitric oxide production, energy metabolism, and protein synthesis after oxygen-glucose deprivation (OGD). Incubating hippocampal slices in LPS (4 mg/L) for as long as 12 h did not alter cGMP tissue concentrations significantly. However, 10 min after OGD of 40-min duration, cGMP tissue concentrations were substantially increased in relation to controls, and this increase was almost completely blocked by the application of 100 microM N:(omega)-nitro-L-arginine, indicating that nitric oxide synthase was activated after OGD in fetal brain tissue. Again, LPS did not have any effect on cGMP tissue concentrations after OGD. Furthermore, addition of LPS altered neither protein synthesis nor energy metabolism measured 12 h after OGD. We therefore conclude that, apart from their well-known influence on the cardiovascular system, LPS do not alter metabolic disturbances in hippocampal slices of fetal guinea pigs 12 h after OGD. A direct toxic effect of LPS on immature brain tissue within this interval does not therefore seem to be very likely. However, delayed activation of LPS-sensitive pathways that may be involved in cell death, or damage limited to a small subgroup of cells such as oligodendrocyte progenitors, cannot be fully excluded.

Identification of Residues in the Lipopolysaccharide ABC Transporter That Coordinate ATPase Activity with Extractor Function

PubMed Central

Simpson, Brent W.; Owens, Tristan W.; Orabella, Matthew J.; Davis, Rebecca M.; May, Janine M.; Trauger, Sunia A.

2016-01-01

ABSTRACT The surface of most Gram-negative bacteria is covered with lipopolysaccharide (LPS), creating a permeability barrier against toxic molecules, including many antimicrobials. To assemble LPS on their surface, Gram-negative bacteria must extract newly synthesized LPS from the inner membrane, transport it across the aqueous periplasm, and translocate it across the outer membrane. The LptA to -G proteins assemble into a transenvelope complex that transports LPS from the inner membrane to the cell surface. The Lpt system powers LPS transport from the inner membrane by using a poorly characterized ATP-binding cassette system composed of the ATPase LptB and the transmembrane domains LptFG. Here, we characterize a cluster of residues in the groove region of LptB that is important for controlling LPS transport. We also provide the first functional characterization of LptFG and identify their coupling helices that interact with the LptB groove. Substitutions at conserved residues in these coupling helices compromise both the assembly and function of the LptB2FG complex. Defects in LPS transport conferred by alterations in the LptFG coupling helices can be rescued by changing a residue in LptB that is adjacent to functionally important residues in the groove region. This suppression is achieved by increasing the ATPase activity of the LptB2FG complex. Taken together, these data identify a specific binding site in LptB for the coupling helices of LptFG that is responsible for coupling of ATP hydrolysis by LptB with LptFG function to achieve LPS extraction. PMID:27795402

Studies of the TLR4-associated protein MD-2 using yeast-display and mutational analyses

PubMed Central

Mattis, Daiva M.; Chervin, Adam; Ranoa, Diana; Kelley, Stacy; Tapping, Richard; Kranz, David M.

2015-01-01

Bacterial lipopolysaccharide (LPS) activates the innate immune system by forming a complex with myeloid differentiation factor 2 (MD-2) and Toll-like receptor 4 (TLR4), which is present on antigen presenting cells. MD-2 plays an essential role in this activation of the innate immune system as a member of the ternary complex, TLR4:MD-2:LPS. With the goal of further understanding the molecular details of the interaction of MD-2 with LPS and TLR4, and possibly toward engineering dominant negative regulators of the MD-2 protein, here we subjected MD-2 to a mutational analysis using yeast display. The approach included generation of site-directed alanine mutants, and ligand-driven selections of MD-2 mutant libraries. Our findings showed that: 1) proline mutations in the F119-K132 loop that binds LPS were strongly selected for enhanced yeast surface stability, 2) there was a preference for positive-charged side chains (R/K) at residue 120 for LPS binding, and negative-charged side chains (D/E) for TLR4 binding, 3) aromatic residues were strongly preferred at F119 and F121 for LPS binding, and 4) an MD-2 mutant (T84N/D101A/S118A/S120D/K122P) exhibited increased binding to TLR4 but decreased binding to LPS. These studies revealed the impact of specific residues and regions of MD-2 on the binding of LPS and TLR4, and they provide a framework for further directed evolution of the MD-2 protein. PMID:26320630

Effect of lipopolysaccharide on the hemocyte apoptosis of Eriocheir sinensis *

PubMed Central

Xu, Hai-sheng; Lyu, Sun-jian; Xu, Jie-hao; Lu, Bin-jie; Zhao, Jing; Li, Song; Li, Yi-qun; Chen, Yu-yin

2015-01-01

In the present study, we investigated the possible toxicity mechanism of lipopolysaccharide (LPS) extracted from Gram-negative bacteria in Eriocheir sinensis hemocytes. Apoptotic hemocytes and reactive oxygen species (ROS) production induced by the LPS were monitored by the combination of flow cytometry and microscope observation. It was shown that LPS induced serious damage on the DNA and morphological changes in hemocytes, including cell shrinkage, fracture of nucleus membrane, margination, condensation and fragmentation of chromatin, and formation of apoptotic bodies indicating obvious hemocyte apoptosis. As compared with the control group, the apoptotic cell ratio increased to 30.61% and 39.01% after 1-h exposure and 57.72% and 75.01% after 2-h exposure to 1 and 10 μg/ml LPS, respectively (P<0.05). Significant outburst of ROS production was observed in LPS-treated hemocytes with approximately 176.6% of relative dichlorofluorescein mean fluorescence at 1-h exposure, followed by a drastic decline (P<0.05). These results indicated that LPS would induce oxidative stress on hemocytes from E. sinensis and cause ROS burst, DNA damage, and subsequently apoptosis. The process of ROS-mediated apoptosis might be one of the potential toxicity mechanisms of LPS on crustacean hemocytes. PMID:26642180

Mifepristone (RU486) restores humoral and T cell-mediated immune response in endotoxin immunosuppressed mice

PubMed Central

Rearte, B; Maglioco, A; Balboa, L; Bruzzo, J; Landoni, V I; Laborde, E A; Chiarella, P; Ruggiero, R A; Fernández, G C; Isturiz, M A

2010-01-01

Sepsis and septic shock can be caused by Gram-positive and -negative bacteria and other microorganisms. In the case of Gram-negative bacteria, endotoxin, a normal constituent of the bacterial wall, also known as lipopolysaccharide (LPS), has been considered as one of the principal agents causing the undesirable effects in this critical illness. The response to LPS involves a rapid secretion of proinflammatory cytokines such as tumour necrosis factor (TNF)-α, interleukin (IL)-1, IL-6, interferon (IFN)-γ and the concomitant induction of anti-inflammatory mediators such as IL-10, transforming growth factor (TGF)-β or glucocorticoids, which render the host temporarily refractory to subsequent lethal doses of LPS challenge in a process known as LPS or endotoxin tolerance. Although protective from the development of sepsis or systemic inflammation, endotoxin tolerance has also been pointed out as the main cause of the non-specific humoral and cellular immunosuppression described in these patients. In this report we demonstrate, using a mouse model, that mifepristone (RU486), a known glucocorticoid receptor antagonist, could play an important role in the restoration of both adaptive humoral and cellular immune response in LPS immunosuppressed mice, suggesting the involvement of endogenous glucocorticoids in this phenomenon. On the other hand, using cyclophosphamide and gemcitabine, we demonstrated that regulatory/suppressor CD4+CD25+forkhead boxP3+ and GR-1+CD11b+ cells do not play a major role in the establishment or the maintenance of endotoxin tolerance, a central mechanism for inducing an immunosuppression state. PMID:20964639

Characterization of the seismically imaged Tuscarora fold system and implications for layer parallel shortening in the Pennsylvania salient

NASA Astrophysics Data System (ADS)

Mount, Van S.; Wilkins, Scott; Comiskey, Cody S.

2017-12-01

The Tuscarora fold system (TFS) is located in the Pennsylvania salient in the foreland of the Valley and Ridge province. The TFS is imaged in high quality 3D seismic data and comprises a system of small-scale folds within relatively flat-lying Lower Silurian Tuscarora Formation strata. We characterize the TFS structures and infer layer parallel shortening (LPS) directions and magnitudes associated with deformation during the Alleghany Orogeny. Previously reported LPS data in our study area are from shallow Devonian and Carboniferous strata (based on outcrop and core analyses) above the shallowest of three major detachments recognized in the region. Seismic data allows us to characterize LPS at depth in strata beneath the shallow detachment. Our LPS data (orientations and inferred magnitudes) are consistent with the shallow data leading us to surmise that LPS during Alleghanian deformation fanned around the salient and was distributed throughout the stratigraphic section - and not isolated to strata above the shallow detachment. We propose that a NW-SE oriented Alleghanian maximum principal stress was perturbed by deep structure associated with the non-linear margin of Laurentia resulting in fanning of shortening directions within the salient.

Peripheral and central mediators of lipopolysaccharide induced suppression of defensive rage behavior in the cat.

PubMed

Bhatt, S; Bhatt, R S; Zalcman, S S; Siegel, A

2009-11-10

Based upon recent findings in our laboratory that cytokines microinjected into the medial hypothalamus or periaqueductal gray (PAG) powerfully modulate defensive rage behavior in cat, the present study determined the effects of peripherally released cytokines following lipopolysaccharide (LPS) challenge upon defensive rage. The study involved initial identification of the effects of peripheral administration of LPS upon defensive rage by electrical stimulation from PAG and subsequent determination of the peripheral and central mechanisms governing this process. The results revealed significant elevation in response latencies for defensive rage from 60 to 300 min, post LPS injection, with no detectable signs of sickness behavior present at 60 min. In contrast, head turning behavior elicited by stimulation of adjoining midbrain sites was not affected by LPS administration, suggesting a specificity of the effects of LPS upon defensive rage. Direct administration of LPS into the medial hypothalamus had no effect on defensive rage, suggesting that the effects of LPS were mediated by peripheral cytokines rather than by any direct actions upon hypothalamic neurons. Complete blockade of the suppressive effects of LPS by peripheral pretreatment with an Anti-tumor necrosis factor-alpha (TNFalpha) antibody but not with an anti- interleukin-1 (IL-1) antibody demonstrated that the effects of LPS were mediated through TNF-alpha rather than through an IL-1 mechanism. A determination of the central mechanisms governing LPS suppression revealed that pretreatment of the medial hypothalamus with PGE(2) or 5-HT(1A) receptor antagonists each completely blocked the suppressive effects of LPS, while microinjections of a TNF-alpha antibody into the medial hypothalamus were ineffective. Microinjections of -Iodo-N-[2-[4-(methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridinyl) benzamide monohydrochloride (p-MPPI) into lateral hypothalamus (to test for anatomical specificity) had no effect upon LPS induced suppression of defensive rage. The results demonstrate that LPS suppresses defensive rage by acting through peripheral TNF-alpha in periphery and that central effects of LPS suppression of defensive rage are mediated through PGE(2) and 5-HT(1A) receptors in the medial hypothalamus.

Vagotomy attenuates brain cytokines and sleep induced by peripherally administered tumor necrosis factor-α and lipopolysaccharide in mice.

PubMed

Zielinski, Mark R; Dunbrasky, Danielle L; Taishi, Ping; Souza, Gianne; Krueger, James M

2013-08-01

Systemic tumor necrosis factor-α (TNF-α) is linked to sleep and sleep altering pathologies in humans. Evidence from animals indicates that systemic and brain TNF-α have a role in regulating sleep. In animals, TNF-α or lipopolysaccharide (LPS) enhance brain pro-inflammatory cytokine expression and sleep after central or peripheral administration. Vagotomy blocks enhanced sleep induced by systemic TNF-α and LPS in rats, suggesting that vagal afferent stimulation by TNF-α enhances pro-inflammatory cytokines in sleep-related brain areas. However, the effects of systemic TNF-α on brain cytokine expression and mouse sleep remain unknown. We investigated the role of vagal afferents on brain cytokines and sleep after systemically applied TNF-α or LPS in mice. Spontaneous sleep was similar in vagotomized and sham-operated controls. Vagotomy attenuated TNF-α- and LPS-enhanced non-rapid eye movement sleep (NREMS); these effects were more evident after lower doses of these substances. Vagotomy did not affect rapid eye movement sleep responses to these substances. NREMS electroencephalogram delta power (0.5-4 Hz range) was suppressed after peripheral TNF-α or LPS injections, although vagotomy did not affect these responses. Compared to sham-operated controls, vagotomy did not affect liver cytokines. However, vagotomy attenuated interleukin-1 beta (IL-1β) and TNF-α mRNA brain levels after TNF-α, but not after LPS, compared to the sham-operated controls. We conclude that vagal afferents mediate peripheral TNF-α-induced brain TNF-α and IL-1β mRNA expressions to affect sleep. We also conclude that vagal afferents alter sleep induced by peripheral pro-inflammatory stimuli in mice similar to those occurring in other species.

The ability of lipopolysaccharide (LPS) of Pasteurella multocida B:2 to induce clinical and pathological lesions in the nervous system of buffalo calves following experimental inoculation.

PubMed

Marza, Ali Dhiaa; Jesse Abdullah, Faez Firdaus; Ahmed, Ihsan Muneer; Teik Chung, Eric Lim; Ibrahim, Hayder Hamzah; Zamri-Saad, Mohd; Omar, Abdul Rahman; Abu Bakar, Md Zuki; Saharee, Abdul Aziz; Haron, Abdul Wahid; Alwan, Mohammed Jwaid; Mohd Lila, Mohd Azmi

2017-03-01

Lipopolysaccharide (LPS) of P. multocida B:2, a causative agent of haemorrhagic septicaemia (HS) in cattle and buffaloes, is considered as the main virulence factor and contribute in the pathogenesis of the disease. Recent studies provided evidences about the involvement of the nervous system in pathogenesis of HS. However, the role of P. multocida B:2 immunogens, especially the LPS is still uncovered. Therefore, this study was designed to investigate the role of P. multocida B:2 LPS to induce pathological changes in the nervous system. Nine eight-month-old, clinically healthy buffalo calves were used and distributed into three groups. Calves of Group 1 and 2 were inoculated orally and intravenously with 10 ml of LPS broth extract represent 1 × 10 12  cfu/ml of P. multocida B:2, respectively, while calves of Group 3 were inoculated orally with 10 ml of phosphate buffer saline as a control. Significant differences were found in the mean scores for clinical signs, post mortem and histopathological changes especially in Group 2, which mainly affect different anatomic regions of the nervous system, mainly the brain. On the other hand, lower scores have been recorded for clinical signs, gross and histopathological changes in Group 1. These results provide for the first time strong evidence about the ability of P. multocida B:2 LPS to cross the blood brain barrier and induce pathological changes in the nervous system of the affected buffalo calves. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cyclooxygenase-2-dependent bronchoconstriction in perfused rat lungs exposed to endotoxin.

PubMed

Uhlig, S; Nüsing, R; von Bethmann, A; Featherstone, R L; Klein, T; Brasch, F; Müller, K M; Ullrich, V; Wendel, A

1996-05-01

Lipopolysaccharides (LPS), widely used to study the mechanisms of gram-negative sepsis, increase airway resistance by constriction of terminal bronchioles. The role of the cyclooxygenase (COX) isoenzymes and their prostanoid metabolites in this process was studied. Pulmonary resistance, the release of thromboxane (TX) and the expression of COX-2 mRNA were measured in isolated blood-free perfused rat lungs exposed to LPS. LPS induced the release of TX and caused increased airway resistance after about 30 min. Both TX formation and LPS-induced bronchoconstriction were prevented by treatment with the unspecific COX inhibitor acetyl salicylic acid, the specific COX-2 inhibitor CGP-28238, dexamethasone, actinomycin D, or cycloheximide. LPS-induced bronchoconstriction was also inhibited by the TX receptor antagonist BM-13177. The TX-mimetic compound, U-46619, increased airway resistance predominantly by constricting terminal bronchioles. COX-2-specific mRNA in lung tissue was elevated after LPS exposure, and this increase was attenuated by addition of dexamethasone or of actinomycin D. In contrast to LPS, platelet-activating factor (PAF) induced immediate TX release and bronchoconstriction that was prevented by acetyl salicylic acid, but not by CGP-28238. LPS elicits the following biochemical and functional changes in rat lungs: (i) induction of COX-2; (ii) formation of prostaglandins and TX; (iii) activation of the TX receptor on airway smooth muscle cells; (iv) constriction of terminal bronchioles; and (v) increased airway resistance. In contrast to LPS, the PAF-induced TX release is likely to depend on COX-1.

Effect of intravenous endotoxin on blood cell profiles of broilers housed in cages and floor litter environments.

PubMed

Wang, W; Wideman, R F; Chapman, M E; Bersi, T K; Erf, G F

2003-12-01

Commercial broilers are constantly exposed to airborne microorganisms and endotoxin (lipopolysaccharide, LPS). It has been shown that microbial contamination of the air was higher in broiler houses using floor litter than in broiler houses using netting-type floors. The current study evaluated the effect of housing conditions on blood leukocyte profiles and tested the hypothesis that, when compared to broilers reared in clean stainless steel cages (Cage group), broilers raised on floor litter (Floor group) should experience a higher environmental challenge and have a desensitized immune system that may exhibit better tolerance/resistance to subsequent intravenous LPS challenge. Hematological parameters were evaluated prior to and following i.v. administration of 1 mg/kg BW Salmonella typhimurium LPS (dissolved at 1 mg/0.25 mL in PBS) or i.v. injection of 0.25 mL/kg BW PBS alone. The results showed that prior to LPS/PBS injection, broilers in the cage group had higher heterophil and monocyte concentrations, a higher B cell percentage within the lymphocyte population, and a higher heterophil to lymphocyte (H:L) ratio in the blood. The i.v. LPS injection resulted in 25% mortality in the cage group and 42% mortality in the floor group within 8 h post-injection. LPS reduced the concentrations of total white blood cells (WBC) and all differential WBC except eosinophils and increased thrombocyte concentrations within 1 h post-injection in both groups. All of these values returned to their respective pre-injection levels within 48 h post-injection in the surviving birds. The two groups exhibited similar overall hematological changes after LPS injection except that the cage group showed a higher H:L ratio at 8 h post-injection and a lower B-cell percentage within the lymphocyte population at 48 h post-injection when compared with the floor group. We concluded that the immune systems of broilers reared on floor litter were desensitized and exhibited less pronounced leukocyte responses to i.v. LPS when compared with those of broilers reared in clean stainless steel cages. However, such desensitization of the immune system did not help broilers survive subsequent i.v. LPS challenge.

The relevance of kalikrein-kinin system via activation of B2 receptor in LPS-induced fever in rats.

PubMed

Soares, Denis de Melo; Santos, Danielle R; Rummel, Christoph; Ott, Daniela; Melo, Míriam C C; Roth, Joachim; Calixto, João B; Souza, Glória E P

2017-11-01

This study evaluated the involvement of endogenous kallikrein-kinin system and the bradykinin (BK) B 1 and B 2 receptors on LPS- induced fever and the POA cells involved in this response. Male Wistar rats received either i.v. (1 mg/kg), i.c.v. (20 nmol) or i.h. (2 nmol) injections of icatibant (B 2 receptor antagonist) 30 or 60 min, respectively, before the stimuli. DALBK (B 1 receptor antagonist) was given either 15min before BK (i.c.v.) or 30 min before LPS (i.v.). Captopril (5 mg/kg, sc.,) was given 1 h prior LPS or BK. Concentrations of BK and total kininogenon CSF, plasma and tissue kallikrein were evaluated. Rectal temperatures (rT) were assessed by telethermometry. Ca ++ signaling in POA cells was performed in rat pup brain tissue microcultures. Icatibant reduced LPS fever while, captopril exacerbated that response, an effect abolished by icatibant. Icatibant (i.h.) reduced fever to BK (i.h.) but not that induced by LPS (i.v.). BK increased intracellular calcium concentration in neurons and astrocytes. LPS increased levels of bradykinin, tissue kallikrein and total kininogen. BK (i.c.v.) increased rT and decreased tail skin temperature. Captopril potentiated BK-induced fever an effect abolished by icatibant. DALBK reduced the fever induced by BK. BK (i.c.v.) increased the CSF PGE 2 concentration. Effect abolished by indomethacin (i.p.). LPS activates endogenous kalikrein-kinin system leading to production of BK, which by acting on B 2 -receptors of POA cells causes prostaglandin synthesis that in turn produces fever. Thus, a kinin B 2 -receptor antagonist that enters into the brain could constitute a new and interesting strategy to treat fever. Copyright © 2017 Elsevier Ltd. All rights reserved.

Vesicular acetylcholine transporter knock down-mice are more susceptible to inflammation, c-Fos expression and sickness behavior induced by lipopolysaccharide.

PubMed

Leite, Hércules Ribeiro; Oliveira-Lima, Onésia Cristina de; Pereira, Luciana de Melo; Oliveira, Vinícius Elias de Moura; Prado, Vania Ferreira; Prado, Marco Antônio Máximo; Pereira, Grace Schenatto; Massensini, André Ricardo

2016-10-01

In addition to the well-known functions as a neurotransmitter, acetylcholine (ACh) can modulate of the immune system. Nonetheless, how endogenous ACh release inflammatory responses is still not clear. To address this question, we took advantage of an animal model with a decreased ACh release due a reduction (knockdown) in vesicular acetylcholine transporter (VAChT) expression (VAChT-KD(HOM)). These animals were challenged with lipopolysaccharide (LPS). Afterwards, we evaluated sickness behavior and quantified systemic and cerebral inflammation as well as neuronal activation in the dorsal vagal complex (DVC). VAChT-KD(HOM) mice that were injected with LPS (10mg/kg) showed increased mortality rate as compared to control mice. In line with this result, a low dose of LPS (0.1mg/kg) increased the levels of pro-inflammatory (TNF-α, IL-1β, and IL-6) and anti-inflammatory (IL-10) cytokines in the spleen and brain of VAChT-KD(HOM) mice in comparison with controls. Similarly, serum levels of TNF-α and IL-6 were increased in VAChT-KD(HOM) mice. This excessive cytokine production was completely prevented by administration of a nicotinic receptor agonist (0.4mg/kg) prior to the LPS injection. Three hours after the LPS injection, c-Fos expression increased in the DVC region of VAChT-KD(HOM) mice compared to controls. In addition, VAChT-KD(HOM) mice showed behavioral changes such as lowered locomotor and exploratory activity and reduced social interaction after the LPS challenge, when compared to control mice. Taken together, our results show that the decreased ability to release ACh exacerbates systemic and cerebral inflammation and promotes neural activation and behavioral changes induced by LPS. In conclusion, our findings support the notion that activity of cholinergic pathways, which can be modulated by VAChT expression, controls inflammatory and neural responses to LPS challenge. Copyright © 2016 Elsevier Inc. All rights reserved.

Nanoparticle distribution during systemic inflammation is size-dependent and organ-specific

NASA Astrophysics Data System (ADS)

Chen, K.-H.; Lundy, D. J.; Toh, E. K.-W.; Chen, C.-H.; Shih, C.; Chen, P.; Chang, H.-C.; Lai, J. J.; Stayton, P. S.; Hoffman, A. S.; Hsieh, P. C.-H.

2015-09-01

This study comprehensively investigates the changing biodistribution of fluorescent-labelled polystyrene latex bead nanoparticles in a mouse model of inflammation. Since inflammation alters systemic circulatory properties, increases vessel permeability and modulates the immune system, we theorised that systemic inflammation would alter nanoparticle distribution within the body. This has implications for prospective nanocarrier-based therapies targeting inflammatory diseases. Low dose lipopolysaccharide (LPS), a bacterial endotoxin, was used to induce an inflammatory response, and 20 nm, 100 nm or 500 nm polystyrene nanoparticles were administered after 16 hours. HPLC analysis was used to accurately quantify nanoparticle retention by each vital organ, and tissue sections revealed the precise locations of nanoparticle deposition within key tissues. During inflammation, nanoparticles of all sizes redistributed, particularly to the marginal zones of the spleen. We found that LPS-induced inflammation induces splenic macrophage polarisation and alters leukocyte uptake of nanoparticles, with size-dependent effects. In addition, spleen vasculature becomes significantly more permeable following LPS treatment. We conclude that systemic inflammation affects nanoparticle distribution by multiple mechanisms, in a size dependent manner.This study comprehensively investigates the changing biodistribution of fluorescent-labelled polystyrene latex bead nanoparticles in a mouse model of inflammation. Since inflammation alters systemic circulatory properties, increases vessel permeability and modulates the immune system, we theorised that systemic inflammation would alter nanoparticle distribution within the body. This has implications for prospective nanocarrier-based therapies targeting inflammatory diseases. Low dose lipopolysaccharide (LPS), a bacterial endotoxin, was used to induce an inflammatory response, and 20 nm, 100 nm or 500 nm polystyrene nanoparticles were administered after 16 hours. HPLC analysis was used to accurately quantify nanoparticle retention by each vital organ, and tissue sections revealed the precise locations of nanoparticle deposition within key tissues. During inflammation, nanoparticles of all sizes redistributed, particularly to the marginal zones of the spleen. We found that LPS-induced inflammation induces splenic macrophage polarisation and alters leukocyte uptake of nanoparticles, with size-dependent effects. In addition, spleen vasculature becomes significantly more permeable following LPS treatment. We conclude that systemic inflammation affects nanoparticle distribution by multiple mechanisms, in a size dependent manner. Electronic supplementary information (ESI) available: IF images of brain, heart, low magnification images of spleen, mouse heart rate and blood pressure post-LPS. See DOI: 10.1039/c5nr03626g

Dietary L-arginine supplementation modulates lipopolysaccharide-induced systemic inflammatory response in broiler chickens

USDA-ARS?s Scientific Manuscript database

This study was conducted to evaluate whether dietary supplementation with L-arginine (Arg) could attenuate lipopolysaccharide (LPS)-induced systemic inflammatory response through LPS/TLR-4 signaling pathway in broilers. The experiment was designed as a 2 × 3 factorial arrangement (n = 8 cages/treatm...

LYATK1 potently inhibits LPS-mediated pro-inflammatory response

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xi, Feng; Liu, Yuan; Wang, Xiujuan

Lipopolysaccharide (LPS)-primed monocytes/macrophages produce pro-inflammatory cytokines, which could lead to endotoxin shock. TGF-β-activated kinase1 (TAK1) activation is involved in the process. In the current study, we studied the potential effect of a selective TAK1 inhibitor, LYTAK1, on LPS-stimulated response both in vitro and in vivo. We demonstrated that LYTAK1 inhibited LPS-induced mRNA expression and production of several pro-inflammatory cytokines [interleukin 1β (IL-1β), tumor necrosis factor-α (TNFα) and interleukin-6 (IL-6)] in RAW 264.7 macrophages. LYTAK1's activity was almost nullified with TAK1 shRNA-knockdown. Meanwhile, in both primary mouse bone marrow derived macrophages (BMDMs) and human peripheral blood mononuclear cells (PBMCs), LPS-induced pro-inflammatory cytokine productionmore » was again attenuated with LYTAK1 co-treatment. Molecularly, LYTAK1 dramatically inhibited LPS-induced TAK1-nuclear factor kappa B (NFκB) and mitogen-activated protein kinase (Erk, Jnk and p38) activation in RAW 264.7 cells, mouse BMDMs and human PBMCs. In vivo, oral administration of LYTAK1 inhibited LPS-induced activation of TAK1-NFκB-p38 in ex-vivo cultured PBMCs, and cytokine production and endotoxin shock in mice. Together, these results demonstrate that LYTAK1 inhibits LPS-induced production of several pro-inflammatory cytokines and endotoxin shock probably through blocking TAK1-regulated signalings. - Highlights: • LYTAK1 inhibits LPS-induced pro-inflammatory cytokine production in RAW 264.7 cells. • The effect by LYTAK1 is more potent than other known TAK1 inhibitors. • LYTAK1 inhibits LPS-induced cytokine production in primary macrophages/monocytes. • LYTAK1 inhibits LPS-induced TAK1-NFκB and MAPK activation in macrophages/monocytes. • LYTAK1 gavage inhibits LPS-induced endotoxin shock and cytokine production in mice.« less

Progesterone modulates the LPS-induced nitric oxide production by a progesterone-receptor independent mechanism.

PubMed

Wolfson, Manuel Luis; Schander, Julieta Aylen; Bariani, María Victoria; Correa, Fernando; Franchi, Ana María

2015-12-15

Genital tract infections caused by Gram-negative bacteria induce miscarriage and are one of the most common complications of human pregnancy. LPS administration to 7-day pregnant mice induces embryo resorption after 24h, with nitric oxide playing a fundamental role in this process. We have previously shown that progesterone exerts protective effects on the embryo by modulating the inflammatory reaction triggered by LPS. Here we sought to investigate whether the in vivo administration of progesterone modulated the LPS-induced nitric oxide production from peripheral blood mononuclear cells from pregnant and non-pregnant mice. We found that progesterone downregulated LPS-induced nitric oxide production by a progesterone receptor-independent mechanism. Moreover, our results suggest a possible participation of glucocorticoid receptors in at least some of the anti-inflammatory effects of progesterone. Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of betaine on lipopolysaccharide-induced memory impairment in mice and the involvement of GABA transporter 2

PubMed Central

2011-01-01

Background Betaine (glycine betaine or trimethylglycine) plays important roles as an osmolyte and a methyl donor in animals. While betaine is reported to suppress expression of proinflammatory molecules and reduce oxidative stress in aged rat kidney, the effects of betaine on the central nervous system are not well known. In this study, we investigated the effects of betaine on lipopolysaccharide (LPS)-induced memory impairment and on mRNA expression levels of proinflammatory molecules, glial markers, and GABA transporter 2 (GAT2), a betaine/GABA transporter. Methods Mice were continuously treated with betaine for 13 days starting 1 day before they were injected with LPS, or received subacute or acute administration of betaine shortly before or after LPS injection. Then, their memory function was evaluated using Y-maze and novel object recognition tests 7 and 10-12 days after LPS injection (30 μg/mouse, i.c.v.), respectively. In addition, mRNA expression levels in hippocampus were measured by real-time RT-PCR at different time points. Results Repeated administration of betaine (0.163 mmol/kg, s.c.) prevented LPS-induced memory impairment. GAT2 mRNA levels were significantly increased in hippocampus 24 hr after LPS injection, and administration of betaine blocked this increase. However, betaine did not affect LPS-induced increases in levels of mRNA related to inflammatory responses. Both subacute administration (1 hr before, and 1 and 24 hr after LPS injection) and acute administration (1 hr after LPS injection) of betaine also prevented LPS-induced memory impairment in the Y-maze test. Conclusions These data suggest that betaine has protective effects against LPS-induced memory impairment and that prevention of LPS-induced changes in GAT2 mRNA expression is crucial to this ameliorating effect. PMID:22053950

Intermittent fasting attenuates lipopolysaccharide-induced neuroinflammation and memory impairment.

PubMed

Vasconcelos, Andrea R; Yshii, Lidia M; Viel, Tania A; Buck, Hudson S; Mattson, Mark P; Scavone, Cristoforo; Kawamoto, Elisa M

2014-05-06

Systemic bacterial infections often result in enduring cognitive impairment and are a risk factor for dementia. There are currently no effective treatments for infection-induced cognitive impairment. Previous studies have shown that intermittent fasting (IF) can increase the resistance of neurons to injury and disease by stimulating adaptive cellular stress responses. However, the impact of IF on the cognitive sequelae of systemic and brain inflammation is unknown. Rats on IF for 30 days received 1 mg/kg of lipopolysaccharide (LPS) or saline intravenously. Half of the rats were subjected to behavioral tests and the other half were euthanized two hours after LPS administration and the hippocampus was dissected and frozen for analyses. Here, we report that IF ameliorates cognitive deficits in a rat model of sepsis by a mechanism involving NF-κB activation, suppression of the expression of pro-inflammatory cytokines, and enhancement of neurotrophic support. Treatment of rats with LPS resulted in deficits in cognitive performance in the Barnes maze and inhibitory avoidance tests, without changing locomotor activity, that were ameliorated in rats that had been maintained on the IF diet. IF also resulted in reduced levels of mRNAs encoding the LPS receptor TLR4 and inducible nitric oxide synthase (iNOS) in the hippocampus. Moreover, IF prevented LPS-induced elevation of IL-1α, IL-1β and TNF-α levels, and prevented the LPS-induced reduction of BDNF levels in the hippocampus. IF also significantly attenuated LPS-induced elevations of serum IL-1β, IFN-γ, RANTES, TNF-α and IL-6 levels. Taken together, our results suggest that IF induces adaptive responses in the brain and periphery that can suppress inflammation and preserve cognitive function in an animal model of systemic bacterial infection.

Intermittent fasting attenuates lipopolysaccharide-induced neuroinflammation and memory impairment

PubMed Central

2014-01-01

Background Systemic bacterial infections often result in enduring cognitive impairment and are a risk factor for dementia. There are currently no effective treatments for infection-induced cognitive impairment. Previous studies have shown that intermittent fasting (IF) can increase the resistance of neurons to injury and disease by stimulating adaptive cellular stress responses. However, the impact of IF on the cognitive sequelae of systemic and brain inflammation is unknown. Methods Rats on IF for 30 days received 1 mg/kg of lipopolysaccharide (LPS) or saline intravenously. Half of the rats were subjected to behavioral tests and the other half were euthanized two hours after LPS administration and the hippocampus was dissected and frozen for analyses. Results Here, we report that IF ameliorates cognitive deficits in a rat model of sepsis by a mechanism involving NF-κB activation, suppression of the expression of pro-inflammatory cytokines, and enhancement of neurotrophic support. Treatment of rats with LPS resulted in deficits in cognitive performance in the Barnes maze and inhibitory avoidance tests, without changing locomotor activity, that were ameliorated in rats that had been maintained on the IF diet. IF also resulted in reduced levels of mRNAs encoding the LPS receptor TLR4 and inducible nitric oxide synthase (iNOS) in the hippocampus. Moreover, IF prevented LPS-induced elevation of IL-1α, IL-1β and TNF-α levels, and prevented the LPS-induced reduction of BDNF levels in the hippocampus. IF also significantly attenuated LPS-induced elevations of serum IL-1β, IFN-γ, RANTES, TNF-α and IL-6 levels. Conclusions Taken together, our results suggest that IF induces adaptive responses in the brain and periphery that can suppress inflammation and preserve cognitive function in an animal model of systemic bacterial infection. PMID:24886300

On the climate model simulation of Indian monsoon low pressure systems and the effect of remote disturbances and systematic biases

NASA Astrophysics Data System (ADS)

Levine, Richard C.; Martin, Gill M.

2018-06-01

Monsoon low pressure systems (LPS) are synoptic-scale systems forming over the Indian monsoon trough region, contributing substantially to seasonal mean summer monsoon rainfall there. Many current global climate models (GCMs), including the Met Office Unified Model (MetUM), show deficient rainfall in this region, much of which has previously been attributed to remote systematic biases such as excessive equatorial Indian Ocean (EIO) convection, while also substantially under-representing LPS and associated rainfall as they travel westwards across India. Here the sources and sensitivities of LPS to local, remote and short-timescale forcing are examined, in order to understand the poor representation in GCMs. An LPS tracking method is presented using TRACK feature tracking software for comparison between re-analysis data-sets, MetUM GCM and regional climate model (RCM) simulations. RCM simulations, at similar horizontal resolution to the GCM and forced with re-analysis data at the lateral boundaries, are carried out with different domains to examine the effects of remote biases. The results suggest that remote biases contribute significantly to the poor simulation of LPS in the GCM. As these remote systematic biases are common amongst many current GCMs, it is likely that GCMs are intrinsically capable of representing LPS, even at relatively low resolution. The main problem areas are time-mean excessive EIO convection and poor representation of precursor disturbances transmitted from the Western Pacific. The important contribution of the latter is established using RCM simulations forced by climatological 6-hourly lateral boundary conditions, which also highlight the role of LPS in moving rainfall from steep orography towards Central India.

Friedelane-type triterpenoids as selective anti-inflammatory agents by regulation of differential signaling pathways in LPS-stimulated macrophages

DOE Office of Scientific and Technical Information (OSTI.GOV)

Villar-Lorenzo, Andrea, E-mail: avillar@iib.uam.es

A series of 31 pentacyclic triterpenoids isolated from the root barks of Celastrus vulcanicola and Maytenus jelskii were tested for cytotoxicity and inhibitory activity against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 macrophages. Compounds 18 (C18) and 25 (C25) exhibited significant inhibition of LPS-induced NO release at 50 and 25 μM concentrations, respectively, and decreased mRNAs of pro-inflammatory cytokines. At the molecular level, C18 neither inhibited LPS-mediated phosphorylation of mitogen activated protein kinases (MAPKs) nor nuclear translocation of nuclear factor kappa beta (NFκB). Instead, C18 enhanced and prolonged nuclear translocation of nuclear factor-erythroid 2-related factor 2 (Nrf2) andmore » increased the expression of its target genes including hemeoxigenase 1 (HO1). C25 efficiently inhibited LPS-mediated phosphorylation of JNK, p38 and ERK, without affecting NFκB or Nrf2 signaling pathways. Both compounds reduced LPS-mediated processing of caspase-1 and the cleavage of interleukin 1β (IL1β) proform, reflecting their ability to target the inflammasome. C25 also counteracted LPS effects on iNOS expression and pro-inflammatory cytokines mRNA levels in Bv-2 microglial cells. The anti-inflammatory effect of both compounds was also assessed in human macrophages. Our results suggest that triterpenoids C18 and C25 possess anti-inflammatory effects, which may be therapeutically relevant for diseases linked to inflammation. - Highlights: • Compounds 18 (C18) and 25 (C25) exert anti-inflammatory effects in macrophages. • C18 enhanced nuclear translocation of Nrf2 and increased HO1 expression. • C25 inhibited the phosphorylation of JNK, p38 and ERK, members of the MAPKs family. • C25 reduced LPS-mediated processing of caspase-1 and the cleavage of interleukin 1β. • C18 and C25 may be therapeutic agents for diseases linked to inflammation.« less

Klotho preservation by Rhein promotes toll-like receptor 4 proteolysis and attenuates lipopolysaccharide-induced acute kidney injury.

PubMed

Bi, Fangfang; Chen, Fang; Li, Yanning; Wei, Ai; Cao, Wangsen

2018-05-05

Renal anti-aging protein Klotho exhibits impressive properties of anti-inflammation and renal protection, however is suppressed early after renal injury, making Klotho restoration an attractive strategy of treating renal inflammatory disorders. Here, we reported that Klotho is enriched in macrophages and Klotho preservation by Rhein, an anthraquinone derived from medicinal plant rhubarb, attenuates lipopolysaccharide (LPS)-induced acute inflammation essentially via promoting toll-like receptor 4 (TLR4) degradation. LPS-induced pro-inflammatory NF-κB signaling and cytokine expressions coincided with Klotho repression and toll-like receptor 4 (TLR4) elevation in macrophages, renal epithelial cells, and acutely- inflamed kidney. Intriguingly, Rhein treatment effectively corrected the inverted alterations of Klotho and TLR4 and mitigated the TLR4 downstream inflammatory response in a Klotho restoration and TLR4 repression-dependent manner. Klotho inducibly associated with TLR4 after LPS stimulation and suppressed TLR4 protein abundance mainly via a proteolytic process sensitive to the inhibition of Klotho's putative β-glucuronidase activity. Consistently, Klotho knockdown by RNA interferences largely diminished the anti-inflammatory and renal protective effects of Rhein in a mouse model of acute kidney injury incurred by LPS. Thus, Klotho suppression of TLR4 via deglycosylation negatively controls TLR-associated inflammatory signaling and the endogenous Klotho preservation by Rhein or possibly other natural or synthetic compounds possesses promising potentials in the clinical treatment of renal inflammatory disorders. • Klotho is highly expressed in macrophages and repressed by LPS in vitro and in vivo. • Klotho inhibits LPS-induced TLR4 accumulation and the downstream signaling. • Klotho decreases TLR4 via a deglycosylation-associated proteolytic process. • Rhein effectively prevents acute inflammation-incurred Klotho suppression. • Rhein reversal of Klotho attenuates LPS-induced acute inflammation and kidney injury.

Effects of invasion history on physiological responses to immune system activation in invasive Australian cane toads

PubMed Central

West, Andrea J.; Brown, Gregory P.; Fanson, Kerry V.; Addison, BriAnne; Rollins, Lee A.; Shine, Richard

2017-01-01

The cane toad (Rhinella marina) has undergone rapid evolution during its invasion of tropical Australia. Toads from invasion front populations (in Western Australia) have been reported to exhibit a stronger baseline phagocytic immune response than do conspecifics from range core populations (in Queensland). To explore this difference, we injected wild-caught toads from both areas with the experimental antigen lipopolysaccharide (LPS, to mimic bacterial infection) and measured whole-blood phagocytosis. Because the hypothalamic-pituitary-adrenal axis is stimulated by infection (and may influence immune responses), we measured glucocorticoid response through urinary corticosterone levels. Relative to injection of a control (phosphate-buffered saline), LPS injection increased both phagocytosis and the proportion of neutrophils in the blood. However, responses were similar in toads from both populations. This null result may reflect the ubiquity of bacterial risks across the toad’s invaded range; utilization of this immune pathway may not have altered during the process of invasion. LPS injection also induced a reduction in urinary corticosterone levels, perhaps as a result of chronic stress. PMID:29018604

The effect of non-steroidal anti-inflammatory agents on behavioural changes and cytokine production following systemic inflammation: Implications for a role of COX-1

PubMed Central

Teeling, J.L.; Cunningham, C.; Newman, T.A.; Perry, V.H.

2010-01-01

Systemic inflammation gives rise to metabolic and behavioural changes, largely mediated by pro-inflammatory cytokines and prostaglandin production (PGE2) at the blood–brain barrier. Despite numerous studies, the exact biological pathways that give rise to these changes remains elusive. This study investigated the mechanisms underlying immune-to-brain communication following systemic inflammation using various anti-inflammatory agents. Mice were pre-treated with selective cyclo-oxygenase (COX) inhibitors, thromboxane synthase inhibitors or dexamethasone, followed by intra-peritoneal injection of lipopolysaccharide (LPS). Changes in body temperature, open-field activity, and burrowing were assessed and mRNA and/or protein levels of inflammatory mediators measured in serum and brain. LPS-induced systemic inflammation resulted in behavioural changes and increased production of IL-6, IL-1β and TNF-α, as well as PGE2 in serum and brain. Indomethacin and ibuprofen reversed the effect of LPS on behaviour without changing peripheral or central IL-6, IL-1β and TNF-α mRNA levels. In contrast, dexamethasone did not alter LPS-induced behavioural changes, despite complete inhibition of cytokine production. A selective COX-1 inhibitor, piroxicam, but not the selective COX-2 inhibitor, nimesulide, reversed the LPS-induced behavioural changes without affecting IL-6, IL-1β and TNF-α protein expression levels in the periphery or mRNA levels in the hippocampus. Our results suggest that the acute LPS-induced changes in burrowing and open-field activity depend on COX-1. We further show that COX-1 is not responsible for the induction of brain IL-6, IL-1β and TNF-α synthesis or LPS-induced hypothermia. Our results may have implications for novel therapeutic strategies to treat or prevent neurological diseases with an inflammatory component. PMID:19931610

Exacerbated febrile responses to LPS, but not turpentine, in TNF double receptor-knockout mice.

PubMed

Leon, L R; Kozak, W; Peschon, J; Kluger, M J

1997-02-01

We examined the effects of injections of systemic [lipopolysaccharide (LPS), 2.5 mg/kg or 50 pg/kg ip] or local (turpentine, 100 microl sc) inflammatory stimuli on fever, motor activity, body weight, and food intake in tumor necrosis factor (TNF) double receptor (TNFR)-knockout mice. A high dose of LPS resulted in exacerbated fevers in TNFR-knockout mice compared with wild-type mice for the early phase of fever (3-15 h); the late phase of fever (16-24 h) and fevers to a low dose of LPS were similar in both groups. Motor activity, body weight, and food intake were similarly reduced in both groups of mice after LPS administration. In response to turpentine, TNFR-knockout and wild-type mice developed virtually identical responses to all variables monitored. These results suggest that 1) TNF modulates fevers to LPS dose dependently, 2) TNF does not modulate fevers to a subcutaneous injection of turpentine, and 3) knockout mice may develop cytokine redundancy in the regulation of the acute phase response to intraperitoneally injected LPS or subcutaneously injected turpentine.

Docosahexaenoic acid Confers Neuroprotection in a Rat Model of Perinatal Hypoxia-ischemia potentiated by E. coli lipopolysaccharide-induced systemic inflammation

PubMed Central

BERMAN, Deborah R; LIU, YiQing; BARKS, John; MOZURKEWICH, Ellen

2010-01-01

Objective Lipopolysaccharide (LPS) pretreatment potentiates HI injury. We hypothesized that docosahexaenoic acid (DHA) pretreatment would improve function and reduce brain damage in this rat model of perinatal brain injury and inflammation. Study Design Seven-day-old Wistar rats were divided into 3 groups. One received intraperitoneal (IP) DHA 1 mg/kg and LPS 0.1mg/kg. The second received 25% Albumin and LPS. The third received normal saline (NS). Injections were given 2.5 hours prior to right carotid ligation, followed by 90 minutes 8% O2. Rats underwent sensorimotor testing and brain damage assessment on P14. Results DHA pretreatment improved forepaw placing compared to albumin/LPS. (Mean±SD successes/10 trials: 8.57±1.7 DHA/LPS vs 6.72±2.2 Albumin/LPS, p<.0009). There were no significant differences in brain damage among groups. Conclusions Inflammatory stimulation before HI resulted in poorer function than HI alone. Although DHA pretreatment had no impact on brain damage, it significantly improved function in neonatal rats exposed to LPS and HI. PMID:19254588

Inhibition of nitric oxide in LPS-stimulated macrophages of young and senescent mice by δ-tocotrienol and quercetin

PubMed Central

2011-01-01

Background Changes in immune function believed to contribute to a variety of age-related diseases have been associated with increased production of nitric oxide (NO). We have recently reported that proteasome inhibitors (dexamethasone, mevinolin, quercetin, δ-tocotrienol, and riboflavin) can inhibit lipopolysaccharide (LPS)-induced NO production in vitro by RAW 264.7 cells and by thioglycolate-elicited peritoneal macrophages derived from four strains of mice (C57BL/6, BALB/c, LMP7/MECL-1-/- and PPAR-α-/- knockout mice). The present study was carried out in order to further explore the potential effects of diet supplementation with naturally-occurring inhibitors (δ-tocotrienol and quercetin) on LPS-stimulated production of NO, TNF-α, and other pro-inflammatory cytokines involved in the ageing process. Young (4-week-old) and senescent mice (42-week old) were fed control diet with or without quercetin (100 ppm), δ-tocotrienol (100 ppm), or dexamethasone (10 ppm; included as positive control for suppression of inflammation) for 4 weeks. At the end of feeding period, thioglycolate-elicited peritoneal macrophages were collected, stimulated with LPS, LPS plus interferon-β (IFN-β), or LPS plus interferon-γ (IFN-γ), and inflammatory responses assessed as measured by production of NO and TNF-α, mRNA reduction for TNF-α, and iNOS genes, and microarray analysis. Results Thioglycolate-elicited peritoneal macrophages prepared after four weeks of feeding, and then challenged with LPS (10 ng or 100 ng) resulted in increases of 55% and 73%, respectively in the production of NO of 46-week-old compared to 8-week-old mice fed control diet alone (respective control groups), without affecting the secretion of TNF-α among these two groups. However, macrophages obtained after feeding with quercetin, δ-tocotrienol, and dexamethasone significantly inhibited (30% to 60%; P < 0.02) the LPS-stimulated NO production, compared to respective control groups. There was a 2-fold increase in the production of NO, when LPS-stimulated macrophages of quercetin, δ-tocotrienol, or dexamethasone were also treated with IFN-β or IFN-γ compared to respective control groups. We also demonstrated that NO levels and iNOS mRNA expression levels were significantly higher in LPS-stimulated macrophages from senescent (0.69 vs 0.41; P < 0.05), compared to young mice. In contrast, age did not appear to impact levels of TNF-α protein or mRNA expression levels (0.38 vs 0.35) in LPS-stimulated macrophages. The histological analyses of livers of control groups showed lesions of peliosis and microvesicular steatosis, and treated groups showed Councilman body, and small or large lymphoplasmacytic clusters. Conclusions The present results demonstrated that quercetin and δ-tocotrienols inhibit the LPS-induced NO production in vivo. The microarray DNA analyses, followed by pathway analyses indicated that quercetin or δ-tocotrienol inhibit several LPS-induced expression of several ageing and pro-inflammatory genes (IL-1β, IL-1α, IL-6, TNF-α, IL-12, iNOS, VCAM1, ICAM1, COX2, IL-1RA, TRAF1 and CD40). The NF-κB pathway regulates the production of NO and inhibits the pro-inflammatory cytokines involved in normal and ageing process. These ex vivo results confirmed the earlier in vitro findings. The present findings of inhibition of NO production by quercetin and δ-tocotrienol may be of clinical significance treating several inflammatory diseases, including ageing process. PMID:22185406

Pushing the lipid envelope: using bio-inspired nanocomposites to understand and exploit lipid membrane limitations

NASA Astrophysics Data System (ADS)

Montano, Gabriel

Lipids serve as the organizing matrix material for biological membranes, the site of interaction of cells with the external environment. . As such, lipids play a critical role in structure/function relationships of an extraordinary number of critical biological processes. In this talk, we will look at bio-inspired membrane assemblies to better understand the roles of lipids in biological systems as well as attempt to generate materials that can mimic and potentially advance upon biological membrane processes. First, we will investigate the response of lipids to adverse conditions. In particular, I will present data that demonstrates the response of lipids to harsh conditions and how such responses can be exploited to generate nanocomposite rearrangements. I will also show the effect of adding the endotoxin lipopolysaccharide (LPS) to lipid bilayer assemblies and describe implications on our understanding of LPS organization in biological systems as well as describe induced lipid modifications that can be exploited to organize membrane composites with precise, two-dimensional geometric control. Lastly, I will describe the use of amphiphilic block copolymers to create membrane nanocomposites capable of mimicking biological systems. In particular, I will describe the use of our polymer-based membranes in creating artificial photosynthetic assemblies that rival biological systems in function in a more flexible, dynamic matrix.

Extracellular forms of IL-37 inhibit innate inflammation in vitro and in vivo but require the IL-1 family decoy receptor IL-1R8.

PubMed

Li, Suzhao; Neff, C Preston; Barber, Kristina; Hong, Jaewoo; Luo, Yuchun; Azam, Tania; Palmer, Brent E; Fujita, Mayumi; Garlanda, Cecilia; Mantovani, Alberto; Kim, Soohyun; Dinarello, Charles Anthony

2015-02-24

Similar to IL-1α and IL-33, IL-1 family member IL-37b translocates to the nucleus and is associated with suppression of innate and adaptive immunity. Here we demonstrate an extracellular function of the IL-37 precursor and a processed form. Recombinant IL-37 precursor reduced LPS-induced IL-6 by 50% (P < 0.001) in highly inflammatory human blood-derived M1 differentiated macrophages derived from selective subjects but not M2 macrophages. In contrast, a neutralizing monoclonal anti-IL-37 increased LPS-induced IL-6, TNFα and IL-1β (P < 0.01). The suppression by IL-37 was consistently observed at low picomolar but not nanomolar concentrations. Whereas LPS induced a 12-fold increase in TNFα mRNA, IL-37 pretreatment decreased the expression to only 3-fold over background (P < 0.01). Mechanistically, LPS-induced p38 and pERK were reduced by IL-37. Recombinant IL-37 bound to the immobilized ligand binding α-chain of the IL-18 receptor as well as to the decoy receptor IL-1R8. In M1 macrophages, LPS increased the surface expression of IL-1R8. Compared with human blood monocytes, resting M1 cells express more surface IL-1R8 as well as total IL-1R8; there was a 16-fold increase in IL-1R8 mRNA levels when pretreated with IL-37. IL-37 reduced LPS-induced TNFα and IL-6 by 50-55% in mouse bone marrow-derived dendritic cells, but not in dendritic cells derived from IL-1R8-deficient mice. In mice subjected to systemic LPS-induced inflammation, pretreatment with IL-37 reduced circulating and organ cytokine levels. Thus, in addition to a nuclear function, IL-37 acts as an extracellular cytokine by binding to the IL-18 receptor but using the IL-1R8 for its anti-inflammatory properties.

HSP-70 mitigates LPS/SKI-induced cell damage by increasing sphingosine kinase 1 (SK1).

PubMed

Ding, Xuan Z; Feng, Xiao R; Borschel, Richard H; Nikolich, Mikeljon P; Feng, Jie; Li, Yan S; Hoover, David L

2010-06-01

Heat shock proteins (HSPs) are potent protectors of cellular integrity against environmental stresses, including toxic microbial products. To investigate the mechanism of HSP-70 cell protection against bacterial lipopolysaccharide (LPS), we established a stable HSP-70 gene-transfected RAW 264.7 murine macrophage model of LPS-induced cell death. Bacterial LPS increases the activity of sphingosine kinase 1 (SK1), which catalyzes formation of sphingosine-1-phosphate (S1P). S1P functions as a critical signal for initiation and maintenance of diverse aspects of immune cell activation and function. When mouse macrophages were incubated with Escherichia coli LPS (1 microg/ml) and sphingosine kinase inhibitor (SKI, 5 microM), 90% of cells died. Neither LPS nor SKI alone at these doses damaged the cells. The LPS/SKI-induced cell death was partially reversed by overexpression of HSP-70 in gene-transfected macrophages. The specificity of HSP-70 in this reversal was demonstrated by transfection of HSP-70-specific siRNA. Down-regulation of HSP-70 expression after transfection of siRNA specific for HSP-70 was associated with increased LPS/SKI-induced cell damage. Overexpression of human or murine HSP-70 (HSPA1A and Hspa1a, respectively) increased both cellular SK1 mRNA and protein levels. Cellular heat shock also increased SK1 protein. These studies confirm the importance of SK1 as a protective moiety in LPS-induced cell injury and demonstrate that HSP-70-mediated protection from cells treated with LPS/SKI is accompanied by upregulating expression of SK1. HSP-70-mediated increases in SK1 and consequent increased levels of S1P may also play a role in protection of cells from other processes that lead to programmed cell death. Published by Elsevier Inc.

Alterations in dendritic cell function in aged mice: potential implications for immunotherapy design.

PubMed

Paula, Carine; Motta, Adriana; Schmitz, Carla; Nunes, Claudia P; Souza, Ana Paula; Bonorino, Cristina

2009-02-01

It is known that immune system functions decrease with age, and that adaptive immune responses, especially CD4+ T cell function, seem to be the main affected point in immunity with aging. Dendritic cells (DC) are the major antigen presenting cell (APC), and at least part of the defects observed in adaptive immunity of aged individuals could be due to diminished potential of bone marrow to generate new DC, or defects in DC function. In this study, we investigated if the ability of aged bone marrow (BM) to generate new DC in vitro, as well as aged BM-derived DC responses to lypopolysaccharide (LPS). Because DC are important tools in newly developing anti-tumor therapies, we also studied the ability of aged DC to phagocytose and present antigen from necrotic tumor cells. We found that aged BM generated fewer DC in vitro compared to young BM. While LPS-induced DC maturation is reduced in DC of aged mice, a high TNF-alpha production is observed in aged DC even without LPS stimulation. While phagocytosis of tumor cells is not affected by age, and DC derived from aged BM show a higher TNF-alpha production in response to phagocytosis, presentation of tumor antigens was decreased in aged DC. Because class II upregulation in response to phagocytosis was similar between aged and young DC, this could indicate an age associated processing defect in the exogenous pathway. These findings suggest that age of BM used to generate DC does not impair their phagocytic ability or TNF-alpha production, however leads to a decreased yield in mature DC, reduced response to LPS, and diminished antigen processing/presentation potential. Our results are relevant to optimization DC-based vaccine design for aged populations.

Effect of the lactoperoxidase system against three major causal agents of disease in mangoes.

PubMed

Le Nguyen, Doan Duy; Ducamp, Marie-Noelle; Dornier, Manuel; Montet, Didier; Loiseau, Gérard

2005-07-01

The antibacterial activity of the lactoperoxidase system (LPS) on the growth of Xanthomonas campestris, the causal agent of bacterial black spot in mangoes, Botryodiplodia theobromae, the causal agent of stem-end rot disease in mangoes, and Colletotrichum gloeosporioides, the causal agent of anthracnose disease in mangoes, was determined during culture at 30 degrees C and at several pH values (4.5, 5.5, and 6.5). When the results of using the LPS were compared with those from control cultures without the LPS reagents, the growth of the three microorganisms was totally inhibited in all of the conditions tested. Viability tests enumerating cultivable cells of X. campestris showed that the LPS had a bactericidal effect, whatever the pH value. This effect is faster at pH 5.5, corroborating the results reported in the literature (optimal pH for the LPS efficiency). Further, we proved that hydrogen peroxide alone had little inhibition effect on the growth of the microorganisms studied. This compound is essentially used to convert thiocyanate into hypothiocyanate during the lactoperoxidase reaction. The potential of the LPS for the postharvest treatment of the fruits for controlling microbial diseases was thus demonstrated. Nevertheless, further studies are needed on fresh fruits before envisaging any application.

[Study of signal transduction pathway in the expression of inflammatory factors stimulated by lipopolysaccharides from Porphyromonas endodontalis in osteoblasts].

PubMed

Yang, Di; Qiu, Li-hong; Li, Ren; Li, Zi-mu; Li, Chen

2010-04-01

To quantify the interleukin (IL)-1beta mRNA and IL-6 mRNA expression induced by lipopolysaccharides ([PS) extracted from Porphyromonoas endodontalis (P. endodontalis) in osteoblasts, and to relate P. endodontalis LPS to the bone resorptive pathogenesis in the lesions of chronic apical periodontitis. MG63 cells was pretreated with PD98059 or SB203580 for 1 h and then treated with P. endodontolis LPS for 6 h. The expression of IL-1beta mRNA and IL-6 mRNA were detected by reverse transcription polymerase chain reaction (RT-PCR) technique. The production of IL-1beta mRNA induced by P. endodontalis LPS decreased in osteoblasts pretreated with PD98059. Both of the production of IL-1beta mRNA and JL-6 mRNA induced by P. endodontalis LPS decreased in osteoblasts pretreated with SB203580. The synthesis of IL-1beta mRNA stimulated by Pendodontalis LPS in MG63 probably occur via extracellular signal-regulated kinase (ERK) 1/2 and p38 mitogen activated protein kinase (MAPK) signal transduction system. The synthesis of IL-6 mRNA stimulated by P.endodontalis LPS in MG63 probahly occur via p38MAPK signal transduction system.

A signal-on electrochemical aptasensor for ultrasensitive detection of endotoxin using three-way DNA junction-aided enzymatic recycling and graphene nanohybrid for amplification

NASA Astrophysics Data System (ADS)

Bai, Lijuan; Chai, Yaqin; Pu, Xiaoyun; Yuan, Ruo

2014-02-01

Endotoxin, also known as lipopolysaccharide (LPS), is able to induce a strong immune response on its internalization into mammalian cells. To date, aptamer-based biosensors for LPS detection have been rarely reported. This work describes a new signal-on electrochemical aptasensor for the ultrasensitive detection of LPS by combining the three-way DNA hybridization process and nanotechnology-based amplification. With the help of DNA1 (associated with the concentration of target LPS), the capture probe hybridizes with DNA1 and the assistant probe to open its hairpin structure and form a ternary ``Y'' junction structure. The DNA1 can be released from the structure in the presence of nicking endonuclease to initiate the next hybridization process. Then a great deal of cleaved capture probe produced in the cyclic process can bind with DNA2-nanocomposite, which contains the electroactive toluidine blue (Tb) with the amplification materials graphene (Gra) and gold nanoparticles (AuNPs). Thus, an enhanced electrochemical signal can be easily read out. With the cascade signal amplification, this newly designed protocol provides an ultrasensitive electrochemical detection of LPS down to the femtogram level (8.7 fg mL-1) with a linear range of 6 orders of magnitude (from 10 fg mL-1 to 50 ng mL-1). Moreover, the high sensitivity and specificity make this method versatile for the detection of other biomolecules by changing the corresponding sequences of the capture probe and the assistant probe.

Relation of the lunar power system to the SEI program and to landers

NASA Technical Reports Server (NTRS)

Criswell, David R.; Waldron, Robert D.

1992-01-01

The people of Earth will need more than 20,000 billion watts (GWe) of electric power by 2050 for a high level of prosperity. Power needs in the 22nd Century could exceed 100,000 GWe. By 2100 the total quantity of thermal energy used could fully deplete the known inventory (10(exp 7) GWt-Y) of all non-renewable sources on Earth except for deuterium and hydrogen for use in proposed fusion reactors. The labor, capital, and mass of power plants required to produce 1 GWe-Y of energy from present-day power plants is summarized. Fossil and nuclear plants respectively consume 80 to 190 M$ and 12 to 48 M$ of fuel per GWe-Y. The Lunar Power System (LPS) uses solar power bases on the moon to beam electric power to Earth. The LPS in the figure supplies load-following power to rectennas on Earth. Additional solar power conversion units are located across the lunar limb from their respective Earthward transmitting stations. LPS can be augmented by mirrors in polar orbit about the moon. The construction of rectennas on Earth determines the base cost (0.001s$/kWe-H) of LPS power. A manned International Lunar Base (ILB) can accelerate the development of LPS by providing the initial transportation and habitation facilities and base operations. ILB can greatly reduce up front costs and risks by emplacing a moderate scale LPS (1-100 GWe). LPS can accelerate the development of the ILB by providing greater funding than is reasonable to expect for purely scientific research. An international ILB/LPS program can foster world trust and prosperity.

Relation of the lunar power system to the SEI program and to landers

NASA Astrophysics Data System (ADS)

Criswell, David R.; Waldron, Robert D.

The people of Earth will need more than 20,000 billion watts (GWe) of electric power by 2050 for a high level of prosperity. Power needs in the 22nd Century could exceed 100,000 GWe. By 2100 the total quantity of thermal energy used could fully deplete the known inventory (10(exp 7) GWt-Y) of all non-renewable sources on Earth except for deuterium and hydrogen for use in proposed fusion reactors. The labor, capital, and mass of power plants required to produce 1 GWe-Y of energy from present-day power plants is summarized. Fossil and nuclear plants respectively consume 80 to 190 M$ and 12 to 48 M$ of fuel per GWe-Y. The Lunar Power System (LPS) uses solar power bases on the moon to beam electric power to Earth. The LPS in the figure supplies load-following power to rectennas on Earth. Additional solar power conversion units are located across the lunar limb from their respective Earthward transmitting stations. LPS can be augmented by mirrors in polar orbit about the moon. The construction of rectennas on Earth determines the base cost (0.001s$/kWe-H) of LPS power. A manned International Lunar Base (ILB) can accelerate the development of LPS by providing the initial transportation and habitation facilities and base operations. ILB can greatly reduce up front costs and risks by emplacing a moderate scale LPS (1-100 GWe). LPS can accelerate the development of the ILB by providing greater funding than is reasonable to expect for purely scientific research. An international ILB/LPS program can foster world trust and prosperity.

Dexmedetomidine inhibits inflammatory reaction in the hippocampus of septic rats by suppressing NF-κB pathway.

PubMed

Zhang, Xiaobao; Yan, Fang; Feng, Jiying; Qian, Haitao; Cheng, Zhi; Yang, Qianqian; Wu, Yong; Zhao, Zhibin; Li, Aimin; Xiao, Hang

2018-01-01

Dexmedetomidine (DEX) is known to provide neuroprotective effect in the central nervous system. However, the detailed mechanism remains far more elusive. This study was designed to investigate the relevant mechanisms of DEX's neuroprotective effect. Sprague-Dawley (SD) rats were injected with dexmedetomidine and/or Lipopolysaccharide (LPS) intraperitoneally, and inflammatory cytokines in serum and in the hippocampus were measured by enzyme linked immunosorbent assay (ELISA). NF-κB in the brain tissue extracts was analyzed with western-blot. Then, we investigated whether NF-κB inhibitor prevents the elevation of inflammatory cytokines in rats injected with LPS. Our results indicated that compared with the control group, the rats exposed to LPS showed significant cognitive dysfunction. When compared to controls, the levels of TNF-α and IL-6 in the serum and hippocampus homogenate were increased in rats treated with LPS. DEX pretreatment inhibited the rats' TNF-α, IL-6 and NF-κB levels induced by LPS. In response to LPS, PDTC pretreatment restrains the production of proinflammatory cytokines (TNF-α and IL-6). Rats treated with PDTC and DEX alongside LPS exhibited less TNF-α and IL-6 than the LPS treated group. In combination, PDTC and DEX showed addictive effects. Our data suggest that DEX exerts a neuroprotective effect through NF-κB in part after LPS-induced cognitive dysfunction.

Krill Oil-In-Water Emulsion Protects against Lipopolysaccharide-Induced Proinflammatory Activation of Macrophages In Vitro.

PubMed

Bonaterra, Gabriel A; Driscoll, David; Schwarzbach, Hans; Kinscherf, Ralf

2017-03-15

Parenteral nutrition is often a mandatory therapeutic strategy for cases of septicemia. Likewise, therapeutic application of anti-oxidants, anti-inflammatory therapy, and endotoxin lowering, by removal or inactivation, might be beneficial to ameliorate the systemic inflammatory response during the acute phases of critical illness. Concerning anti-inflammatory properties in this setting, omega-3 fatty acids of marine origin have been frequently described. This study investigated the anti-inflammatory and LPS-inactivating properties of krill oil (KO)-in-water emulsion in human macrophages in vitro. Differentiated THP-1 macrophages were activated using specific ultrapure-LPS that binds only on the toll-like receptor 4 (TLR4) in order to determine the inhibitory properties of the KO emulsion on the LPS-binding capacity, and the subsequent release of TNF-α. KO emulsion inhibited the macrophage binding of LPS to the TLR4 by 50% (at 12.5 µg/mL) and 75% (at 25 µg/mL), whereas, at 50 µg/mL, completely abolished the LPS binding. Moreover, KO (12.5 µg/mL, 25 µg/mL, or 50 µg/mL) also inhibited (30%, 40%, or 75%, respectively) the TNF-α release after activation with 0.01 µg/mL LPS in comparison with LPS treatment alone. KO emulsion influences the LPS-induced pro-inflammatory activation of macrophages, possibly due to inactivation of the LPS binding capacity.

Modulation of Caenorhabditis elegans immune response and modification of Shigella endotoxin upon interaction.

PubMed

Kesika, Periyanaina; Prasanth, Mani Iyer; Balamurugan, Krishnaswamy

2015-04-01

To analyze the pathogenesis at both physiological and molecular level using the model organism, Caenorhabditis elegans at different developmental stages in response to Shigella spp. and its pathogen associated molecular patterns such as lipopolysaccharide. The solid plate and liquid culture-based infection assays revealed that Shigella spp. infects C. elegans and had an impact on the brood size and pharyngeal pumping rate. LPS of Shigella spp. was toxic to C. elegans. qPCR analysis revealed that host innate immune genes have been modulated upon Shigella spp. infections and its LPS challenges. Non-destructive analysis was performed to kinetically assess the alterations in LPS during interaction of Shigella spp. with C. elegans. The modulation of innate immune genes attributed the surrendering of host immune system to Shigella spp. by favoring the infection. LPS appeared to have a major role in Shigella-mediated pathogenesis and Shigella employs a tactic behavior of modifying its LPS content to escape from the recognition of host immune system. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Impact of lipopolysaccharide-induced acute inflammation on baroreflex-controlled sympathetic arterial pressure regulation

PubMed Central

Tohyama, Takeshi; Kawada, Toru; Kishi, Takuya; Yoshida, Keimei; Nishikawa, Takuya; Mannoji, Hiroshi; Kamada, Kazuhiro; Sunagawa, Kenji; Tsutsui, Hiroyuki

2018-01-01

Background Lipopolysaccharide (LPS) induces acute inflammation, activates sympathetic nerve activity (SNA) and alters hemodynamics. Since the arterial baroreflex is a negative feedback system to stabilize arterial pressure (AP), examining the arterial baroreflex function is a prerequisite to understanding complex hemodynamics under LPS challenge. We investigated the impact of LPS-induced acute inflammation on SNA and AP regulation by performing baroreflex open-loop analysis. Methods Ten anesthetized Sprague-Dawley rats were used. Acute inflammation was induced by an intravenous injection of LPS (60 μg/kg). We isolated the carotid sinuses from the systemic circulation and controlled carotid sinus pressure (CSP) by a servo-controlled piston pump. We matched CSP to AP to establish the baroreflex closed-loop condition, whereas we decoupled CSP from AP to establish the baroreflex open-loop condition and changed CSP stepwise to evaluate the baroreflex open-loop function. We recorded splanchnic SNA and hemodynamic parameters under baroreflex open- and closed-loop conditions at baseline and at 60 and 120 min after LPS injection. Results In the baroreflex closed-loop condition, SNA continued to increase after LPS injection, reaching three-fold the baseline value at 120 min (baseline: 94.7 ± 3.6 vs. 120 min: 283.9 ± 31.9 a.u.). In contrast, AP increased initially (until 75 min), then declined to the baseline level. In the baroreflex open-loop condition, LPS reset the neural arc (CSP-SNA relationship) upward to higher SNA, while shifted the peripheral arc (SNA-AP relationship) downward at 120 min after the injection. As a result, the operating point determined by the intersection between function curves of neural arc and peripheral arc showed marked sympatho-excitation without substantial changes in AP. Conclusions LPS-induced acute inflammation markedly increased SNA via resetting of the baroreflex neural arc, and suppressed the peripheral arc. The balance between the augmented neural arc and suppressed peripheral arc determines SNA and hemodynamics in LPS-induced acute inflammation. PMID:29329321

Impact of lipopolysaccharide-induced acute inflammation on baroreflex-controlled sympathetic arterial pressure regulation.

PubMed

Tohyama, Takeshi; Saku, Keita; Kawada, Toru; Kishi, Takuya; Yoshida, Keimei; Nishikawa, Takuya; Mannoji, Hiroshi; Kamada, Kazuhiro; Sunagawa, Kenji; Tsutsui, Hiroyuki

2018-01-01

Lipopolysaccharide (LPS) induces acute inflammation, activates sympathetic nerve activity (SNA) and alters hemodynamics. Since the arterial baroreflex is a negative feedback system to stabilize arterial pressure (AP), examining the arterial baroreflex function is a prerequisite to understanding complex hemodynamics under LPS challenge. We investigated the impact of LPS-induced acute inflammation on SNA and AP regulation by performing baroreflex open-loop analysis. Ten anesthetized Sprague-Dawley rats were used. Acute inflammation was induced by an intravenous injection of LPS (60 μg/kg). We isolated the carotid sinuses from the systemic circulation and controlled carotid sinus pressure (CSP) by a servo-controlled piston pump. We matched CSP to AP to establish the baroreflex closed-loop condition, whereas we decoupled CSP from AP to establish the baroreflex open-loop condition and changed CSP stepwise to evaluate the baroreflex open-loop function. We recorded splanchnic SNA and hemodynamic parameters under baroreflex open- and closed-loop conditions at baseline and at 60 and 120 min after LPS injection. In the baroreflex closed-loop condition, SNA continued to increase after LPS injection, reaching three-fold the baseline value at 120 min (baseline: 94.7 ± 3.6 vs. 120 min: 283.9 ± 31.9 a.u.). In contrast, AP increased initially (until 75 min), then declined to the baseline level. In the baroreflex open-loop condition, LPS reset the neural arc (CSP-SNA relationship) upward to higher SNA, while shifted the peripheral arc (SNA-AP relationship) downward at 120 min after the injection. As a result, the operating point determined by the intersection between function curves of neural arc and peripheral arc showed marked sympatho-excitation without substantial changes in AP. LPS-induced acute inflammation markedly increased SNA via resetting of the baroreflex neural arc, and suppressed the peripheral arc. The balance between the augmented neural arc and suppressed peripheral arc determines SNA and hemodynamics in LPS-induced acute inflammation.

Prenatal zinc reduces stress response in adult rat offspring exposed to lipopolysaccharide during gestation.

PubMed

Galvão, Marcella C; Chaves-Kirsten, Gabriela P; Queiroz-Hazarbassanov, Nicolle; Carvalho, Virgínia M; Bernardi, Maria M; Kirsten, Thiago B

2015-01-01

Previous investigations by our group have shown that prenatal treatment with lipopolysaccharide (LPS; 100 μg/kg, intraperitoneally) on gestation day (GD) 9.5 in rats, which mimics infections by Gram-negative bacteria, induces short- and long-term behavioral and neuroimmune changes in the offspring. Because LPS induces hypozincemia, dams were treated with zinc after LPS in an attempt to prevent or ameliorate the impairments induced by prenatal LPS exposure. LPS can also interfere with hypothalamic-pituitary-adrenal (HPA) axis development; thus, behavioral and neuroendocrine parameters linked to HPA axis were evaluated in adult offspring after a restraint stress session. We prenatally exposed Wistar rats to LPS (100 μg/kg, intraperitoneally, on GD 9.5). One hour later they received zinc (ZnSO4, 2 mg/kg, subcutaneously). Adult female offspring that were in metestrus/diestrus were submitted to a 2 h restraint stress session. Immediately after the stressor, 22 kHz ultrasonic vocalizations, open field behavior, serum corticosterone and brain-derived neurotrophic factor (BDNF) levels, and striatal and hypothalamic neurotransmitter and metabolite levels were assessed. Offspring that received prenatal zinc after LPS presented longer periods in silence, increased locomotion, and reduced serum corticosterone and striatal norepinephrine turnover compared with rats treated with LPS and saline. Prenatal zinc reduced acute restraint stress response in adult rats prenatally exposed to LPS. Our findings suggest a potential beneficial effect of prenatal zinc, in which the stress response was reduced in offspring that were stricken with infectious/inflammatory processes during gestation. Copyright © 2014 Elsevier Inc. All rights reserved.

EFFECTS OF CHRONIC EXERCISE CONDITIONING ON THERMAL RESPONSES TO LIPOPOLYSACCHARIDE AND TURPENTINE ABSCESS IN FEMALE RATS.

EPA Science Inventory

Chronic exercise conditioning has been shown to alter basal thermoregulatory processes as well as the response to inflammatory agents. Two such agents, lipopolysaccharide (LPS) and turpentine (TPT) are inducers of fever in rats. LPS, given intraperitoneally (i.p.), involves a sys...

The regulation of Jmjd3 upon the expression of NF-κB downstream inflammatory genes in LPS activated vascular endothelial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Shaoqing; Graduate School of Medicine, Nanchang University, Nanchang; Chen, Xia

Inflammatory mediators and adhesion molecules have been implicated in a variety of diseases including atherosclerosis. As both the mediator-releasing and targeted cells, vascular endothelial cells play key role in pathological processes. NF-κB signaling regulates a cluster of inflammatory factors in LPS-activated vascular endothelial cells but the underlying mechanisms remain largely unknown. Here, we investigated the epigenetic regulation of LPS upon the expression of inflammatory mediators and adhesion molecules. We found that LPS treatment promoted jmjd3 expression, enhanced Jmjd3 nuclear accumulation in human vascular endothelial cells. In addition, LPS enhanced the demethylation of H3K27me3, a specific substrate of Jmjd3. LPS treatmentmore » recruited Jmjd3 and NF-κB to the promoter region of target genes, suggesting Jmjd3 synergizes with NF-κB to activate the expression of target genes. We further found that Jmjd3 attenuated the methylation status in promoter region of target genes, culminating in target gene expression. Our findings unveil epigenetic regulations of LPS upon NF-κB pathway and identify Jmjd3 as a critical modulator of NF-κB pathway and potential therapeutic target for NF-κB related diseases including atherosclerosis.« less

Hypoactivity of the central dopaminergic system and autistic-like behavior induced by a single early prenatal exposure to lipopolysaccharide.

PubMed

Kirsten, Thiago B; Chaves-Kirsten, Gabriela P; Chaible, Lucas M; Silva, Ana C; Martins, Daniel O; Britto, Luiz R G; Dagli, Maria L Z; Torrão, Andrea S; Palermo-Neto, João; Bernardi, Maria M

2012-10-01

The aim of the present study was to evaluate the behavioral patterns associated with autism and the prevalence of these behaviors in males and females, to verify whether our model of lipopolysaccharide (LPS) administration represents an experimental model of autism. For this, we prenatally exposed Wistar rats to LPS (100 μg/kg, intraperitoneally, on gestational day 9.5), which mimics infection by gram-negative bacteria. Furthermore, because the exact mechanisms by which autism develops are still unknown, we investigated the neurological mechanisms that might underlie the behavioral alterations that were observed. Because we previously had demonstrated that prenatal LPS decreases striatal dopamine (DA) and metabolite levels, the striatal dopaminergic system (tyrosine hydroxylase [TH] and DA receptors D1a and D2) and glial cells (astrocytes and microglia) were analyzed by using immunohistochemistry, immunoblotting, and real-time PCR. Our results show that prenatal LPS exposure impaired communication (ultrasonic vocalizations) in male pups and learning and memory (T-maze spontaneous alternation) in male adults, as well as inducing repetitive/restricted behavior, but did not change social interactions in either infancy (play behavior) or adulthood in females. Moreover, although the expression of DA receptors was unchanged, the experimental animals exhibited reduced striatal TH levels, indicating that reduced DA synthesis impaired the striatal dopaminergic system. The expression of glial cell markers was not increased, which suggests that prenatal LPS did not induce permanent neuroinflammation in the striatum. Together with our previous finding of social impairments in males, the present findings demonstrate that prenatal LPS induced autism-like effects and also a hypoactivation of the dopaminergic system. Copyright © 2012 Wiley Periodicals, Inc.

Induction of indolamine 2,3-dioxygenase and kynurenine 3-monooxygenase in rat brain following a systemic inflammatory challenge: a role for IFN-gamma?

PubMed

Connor, Thomas J; Starr, Neasa; O'Sullivan, Joan B; Harkin, Andrew

2008-08-15

Inflammation-mediated dysregulation of the kynurenine pathway has been implicated as a contributor to a number of major brain disorders. Consequently, we examined the impact of a systemic inflammatory challenge on kynurenine pathway enzyme expression in rat brain. Indoleamine 2,3-dioxygenase (IDO) expression was induced in cortex and hippocampus following systemic lipopolysaccharide (LPS) administration. Whilst IDO expression was paralleled by increased circulating interferon (IFN)-gamma concentrations, IFN-gamma expression in the brain was only modestly altered following LPS administration. In contrast, induction of IDO was associated with increased central tumour necrosis factor (TNF)-alpha and interleukin (IL)-6 expression. Similarly, in cultured glial cells LPS-induced IDO expression was accompanied by increased TNF-alpha and IL-6 expression, whereas IFN-gamma was not detectable. These findings indicate that IFN-gamma is not required for LPS-induced IDO expression in brain. A robust increase in kynurenine-3-monooxygenase (KMO) expression was observed in rat brain 24h post LPS, without any change in kynurenine aminotransferase II (KAT II) expression. In addition, we report that constitutive expression of KAT II is approximately 8-fold higher than KMO in cortex and 20-fold higher in hippocampus. Similarly, in glial cells constitutive expression of KAT II was approximately 16-fold higher than KMO, and expression of KMO but not KAT II was induced by LPS. These data are the first to demonstrate that a systemic inflammatory challenge stimulates KMO expression in brain; a situation that is likely to favour kynurenine metabolism in a neurotoxic direction. However, our observation that expression of KAT II is much higher than KMO in rat brain is likely to counteract potential neurotoxicity that could arise from KMO induction following an acute inflammation.

Volcanic Eruption Forecasts From Accelerating Rates of Drumbeat Long-Period Earthquakes

NASA Astrophysics Data System (ADS)

Bell, Andrew F.; Naylor, Mark; Hernandez, Stephen; Main, Ian G.; Gaunt, H. Elizabeth; Mothes, Patricia; Ruiz, Mario

2018-02-01

Accelerating rates of quasiperiodic "drumbeat" long-period earthquakes (LPs) are commonly reported before eruptions at andesite and dacite volcanoes, and promise insights into the nature of fundamental preeruptive processes and improved eruption forecasts. Here we apply a new Bayesian Markov chain Monte Carlo gamma point process methodology to investigate an exceptionally well-developed sequence of drumbeat LPs preceding a recent large vulcanian explosion at Tungurahua volcano, Ecuador. For more than 24 hr, LP rates increased according to the inverse power law trend predicted by material failure theory, and with a retrospectively forecast failure time that agrees with the eruption onset within error. LPs resulted from repeated activation of a single characteristic source driven by accelerating loading, rather than a distributed failure process, showing that similar precursory trends can emerge from quite different underlying physics. Nevertheless, such sequences have clear potential for improving forecasts of eruptions at Tungurahua and analogous volcanoes.

Evaluation of Brain Nuclear Medicine Imaging Tracers in a Murine Model of Sepsis-Associated Encephalopathy.

PubMed

Szöllősi, Dávid; Hegedűs, Nikolett; Veres, Dániel S; Futó, Ildikó; Horváth, Ildikó; Kovács, Noémi; Martinecz, Bernadett; Dénes, Ádám; Seifert, Daniel; Bergmann, Ralf; Lebeda, Ondřej; Varga, Zoltán; Kaleta, Zoltán; Szigeti, Krisztián; Máthé, Domokos

2018-05-07

The purpose of this study was to evaluate a set of widely used nuclear medicine imaging agents as possible methods to study the early effects of systemic inflammation on the living brain in a mouse model of sepsis-associated encephalopathy (SAE). The lipopolysaccharide (LPS)-induced murine systemic inflammation model was selected as a model of SAE. C57BL/6 mice were used. A multimodal imaging protocol was carried out on each animal 4 h following the intravenous administration of LPS using the following tracers: [ 99m Tc][2,2-dimethyl-3-[(3E)-3-oxidoiminobutan-2-yl]azanidylpropyl]-[(3E)-3-hydroxyiminobutan-2-yl]azanide ([ 99m Tc]HMPAO) and ethyl-7-[ 125 I]iodo-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate ([ 125 I]iomazenil) to measure brain perfusion and neuronal damage, respectively; 2-deoxy-2-[ 18 F]fluoro-D-glucose ([ 18 F]FDG) to measure cerebral glucose uptake. We assessed microglia activity on another group of mice using 2-[6-chloro-2-(4-[ 125 I]iodophenyl)-imidazo[1,2-a]pyridin-3-yl]-N-ethyl-N-methyl-acetamide ([ 125 I]CLINME). Radiotracer uptakes were measured in different brain regions and correlated. Microglia activity was also assessed using immunohistochemistry. Brain glutathione levels were measured to investigate oxidative stress. Significantly reduced perfusion values and significantly enhanced [ 18 F]FDG and [ 125 I]CLINME uptake was measured in the LPS-treated group. Following perfusion compensation, enhanced [ 125 I]iomazenil uptake was measured in the LPS-treated group's hippocampus and cerebellum. In this group, both [ 18 F]FDG and [ 125 I]iomazenil uptake showed highly negative correlation to perfusion measured with ([ 99m Tc]HMPAO uptake in all brain regions. No significant differences were detected in brain glutathione levels between the groups. The CD45 and P2Y12 double-labeling immunohistochemistry showed widespread microglia activation in the LPS-treated group. Our results suggest that [ 125 I]CLINME and [ 99m Tc]HMPAO SPECT can be used to detect microglia activation and brain hypoperfusion, respectively, in the early phase (4 h post injection) of systemic inflammation. We suspect that the enhancement of [ 18 F]FDG and [ 125 I]iomazenil uptake in the LPS-treated group does not necessarily reflect neural hypermetabolism and the lack of neuronal damage. They are most likely caused by processes emerging during neuroinflammation, e.g., microglia activation and/or immune cell infiltration.

Effect of Lipopolysaccharide on Inflammation and Insulin Action in Human Muscle

PubMed Central

Liang, Hanyu; Hussey, Sophie E.; Sanchez-Avila, Alicia; Tantiwong, Puntip; Musi, Nicolas

2013-01-01

Accumulating evidence from animal studies suggest that chronic elevation of circulating intestinal-generated lipopolysaccharide (LPS) (i.e., metabolic endotoxemia) could play a role in the pathogenesis of insulin resistance. However, the effect of LPS in human muscle is unclear. Moreover, it is unknown whether blockade/down regulation of toll-like receptor (TLR)4 can prevent the effect of LPS on insulin action and glucose metabolism in human muscle cells. In the present study we compared plasma LPS concentration in insulin resistant [obese non-diabetic and obese type 2 diabetic (T2DM)] subjects versus lean individuals. In addition, we employed a primary human skeletal muscle cell culture system to investigate the effect of LPS on glucose metabolism and whether these effects are mediated via TLR4. Obese non-diabetic and T2DM subjects had significantly elevated plasma LPS and LPS binding protein (LBP) concentrations. Plasma LPS (r = −0.46, P = 0.005) and LBP (r = −0.49, P = 0.005) concentrations negatively correlated with muscle insulin sensitivity (M). In human myotubes, LPS increased JNK phosphorylation and MCP-1 and IL-6 gene expression. This inflammatory response led to reduced insulin-stimulated IRS-1, Akt and AS160 phosphorylation and impaired glucose transport. Both pharmacologic blockade of TLR4 with TAK-242, and TLR4 gene silencing, suppressed the inflammatory response and insulin resistance caused by LPS in human muscle cells. Taken together, these findings suggest that elevations in plasma LPS concentration found in obese and T2DM subjects could play a role in the pathogenesis of insulin resistance and that antagonists of TLR4 may improve insulin action in these individuals. PMID:23704966

Effect of lipopolysaccharide on inflammation and insulin action in human muscle.

PubMed

Liang, Hanyu; Hussey, Sophie E; Sanchez-Avila, Alicia; Tantiwong, Puntip; Musi, Nicolas

2013-01-01

Accumulating evidence from animal studies suggest that chronic elevation of circulating intestinal-generated lipopolysaccharide (LPS) (i.e., metabolic endotoxemia) could play a role in the pathogenesis of insulin resistance. However, the effect of LPS in human muscle is unclear. Moreover, it is unknown whether blockade/down regulation of toll-like receptor (TLR)4 can prevent the effect of LPS on insulin action and glucose metabolism in human muscle cells. In the present study we compared plasma LPS concentration in insulin resistant [obese non-diabetic and obese type 2 diabetic (T2DM)] subjects versus lean individuals. In addition, we employed a primary human skeletal muscle cell culture system to investigate the effect of LPS on glucose metabolism and whether these effects are mediated via TLR4. Obese non-diabetic and T2DM subjects had significantly elevated plasma LPS and LPS binding protein (LBP) concentrations. Plasma LPS (r = -0.46, P = 0.005) and LBP (r = -0.49, P = 0.005) concentrations negatively correlated with muscle insulin sensitivity (M). In human myotubes, LPS increased JNK phosphorylation and MCP-1 and IL-6 gene expression. This inflammatory response led to reduced insulin-stimulated IRS-1, Akt and AS160 phosphorylation and impaired glucose transport. Both pharmacologic blockade of TLR4 with TAK-242, and TLR4 gene silencing, suppressed the inflammatory response and insulin resistance caused by LPS in human muscle cells. Taken together, these findings suggest that elevations in plasma LPS concentration found in obese and T2DM subjects could play a role in the pathogenesis of insulin resistance and that antagonists of TLR4 may improve insulin action in these individuals.

Edaravone abrogates LPS-induced behavioral anomalies, neuroinflammation and PARP-1.

PubMed

Sriram, Chandra Shaker; Jangra, Ashok; Gurjar, Satendra Singh; Mohan, Pritam; Bezbaruah, Babul Kumar

2016-02-01

Poly(ADP-ribose) polymerase-1 (PARP-1) is a DNA nick-sensor enzyme that functions at the center of cellular stress response and affects the immune system at several key points, and thus modulates inflammatory diseases. Our previous study demonstrated that lipopolysaccharide (LPS)-induced depressive-like behavior in mice can be ameliorated by 3-aminobenzamide, which is a PARP-1 inhibitor. In the present study we've examined the effect of a free radical scavenger, edaravone pretreatment against LPS-induced anxiety and depressive-like behavior as well as various hippocampal biochemical parameters including PARP-1. Male Swiss albino mice were treated with edaravone (3 & 10mg/kgi.p.) once daily for 14days. On the 14th day 30min after edaravone treatment mice were challenged with LPS (1mg/kgi.p.). After 3h and 24h of LPS administration we've tested mice for anxiety and depressive-like behaviors respectively. Western blotting analysis of PARP-1 in hippocampus was carried out after 12h of LPS administration. Moreover, after 24h of LPS administration serum corticosterone, hippocampal BDNF, oxido-nitrosative stress and pro-inflammatory cytokines were estimated by ELISA. Results showed that pretreatment of edaravone (10mg/kg) ameliorates LPS-induced anxiety and depressive-like behavior. Western blotting analysis showed that LPS-induced anomalous expression of PARP-1 significantly reverses by the pretreatment of edaravone (10mg/kg). Biochemical analyses revealed that LPS significantly diminishes BDNF, increases pro-inflammatory cytokines and oxido-nitrosative stress in the hippocampus. However, pretreatment with edaravone (10mg/kg) prominently reversed all these biochemical alterations. Our study emphasized that edaravone pretreatment prevents LPS-induced anxiety and depressive-like behavior, mainly by impeding the inflammation, oxido-nitrosative stress and PARP-1 overexpression. Copyright © 2015. Published by Elsevier Inc.

Lipopolysaccharide affects exploratory behaviors toward novel objects by impairing cognition and/or motivation in mice: Possible role of activation of the central amygdala.

PubMed

Haba, Ryota; Shintani, Norihito; Onaka, Yusuke; Wang, Hyper; Takenaga, Risa; Hayata, Atsuko; Baba, Akemichi; Hashimoto, Hitoshi

2012-03-17

Lipopolysaccharide (LPS) produces a series of systemic and psychiatric changes called sickness behavior. In the present study, we characterized the LPS-induced decrease in novel object exploratory behaviors in BALB/c mice. As already reported, LPS (0.3-5 μg/mouse) induced dose- and time-dependent decreases in locomotor activity, food intake, social interaction, and exploration for novel objects, and an increase in immobility in the forced-swim test. Although the decrease in locomotor activity was ameliorated by 10h postinjection, novel object exploratory behaviors remained decreased at 24h and were observed even with the lowest dose of LPS. In an object exploration test, LPS shortened object exploration time but did not affect moving time or the frequency of object exploration. Although pre-exposure to the same object markedly decreased the duration of exploration and LPS did not change this reduction, LPS significantly impaired the exploration of a novel object that replaced the familiar one. LPS did not affect anxiety-like behaviors in open-field and elevated plus-maze tests. An LPS-induced increase in the number of c-Fos-immunoreactive cells was observed in several brain regions within 6h of LPS administration, but the number of cells quickly returned to control levels, except in the central amygdala where the increase continued for 24h. These results suggest that LPS most prominently affects object exploratory behaviors by impairing cognition and/or motivation including continuous attention and curiosity toward objects, and that this may be associated with activation of brain nuclei such as the central amygdala. Copyright © 2012 Elsevier B.V. All rights reserved.

Supramolecular structure of enterobacterial wild-type lipopolysaccharides (LPS), fractions thereof, and their neutralization by Pep19-2.5.

PubMed

Brandenburg, Klaus; Heinbockel, Lena; Correa, Wilmar; Fukuoka, Satoshi; Gutsmann, Thomas; Zähringer, Ulrich; Koch, Michel H J

2016-04-01

Lipopolysaccharides (LPS) belong to the strongest immune-modulating compounds known in nature, and are often described as pathogen-associated molecular patterns (PAMPs). In particular, at higher concentrations they are responsible for sepsis and the septic shock syndrome associated with high lethality. Since most data are indicative that LPS aggregates are the bioactive units, their supramolecular structures are considered to be of outmost relevance for deciphering the molecular mechanisms of its bioactivity. So far, however, most of the data available addressing this issue, were published only for the lipid part (lipid A) and the core-oligosaccharide containing rough LPS, representing the bioactive unit. By contrast, it is well known that most of the LPS specimen identified in natural habitats contain the smooth-form (S-form) LPS, which carry additionally a high-molecular polysaccharide (O-chain). To fill this lacuna and going into a more natural system, here various wild-type (smooth form) LPS including also some LPS fractions were investigated by small-angle X-ray scattering with synchrotron radiation to analyze their aggregate structure. Furthermore, the influence of a recently designed synthetic anti-LPS peptide (SALP) Pep19-2.5 on the aggregate structure, on the binding thermodynamics, and on the cytokine-inducing activity of LPS were characterized, showing defined aggregate changes, high affinity binding and inhibition of cytokine secretion. The data obtained are suitable to refine our view on the preferences of LPS for non-lamellar structures, representing the highest bioactive forms which can be significantly influenced by the binding with neutralizing peptides such as Pep19-2.5. Copyright © 2016 Elsevier Inc. All rights reserved.

LPS-Induced Low-Grade Inflammation Increases Hypothalamic JNK Expression and Causes Central Insulin Resistance Irrespective of Body Weight Changes.

PubMed

Rorato, Rodrigo; Borges, Beatriz de Carvalho; Uchoa, Ernane Torres; Antunes-Rodrigues, José; Elias, Carol Fuzeti; Elias, Lucila Leico Kagohara

2017-07-04

Metabolic endotoxemia contributes to low-grade inflammation in obesity, which causes insulin resistance due to the activation of intracellular proinflammatory pathways, such as the c-Jun N-terminal Kinase (JNK) cascade in the hypothalamus and other tissues. However, it remains unclear whether the proinflammatory process precedes insulin resistance or it appears because of the development of obesity. Hypothalamic low-grade inflammation was induced by prolonged lipopolysaccharide (LPS) exposure to investigate if central insulin resistance is induced by an inflammatory stimulus regardless of obesity. Male Wistar rats were treated with single (1 LPS) or repeated injections (6 LPS) of LPS (100 μg/kg, IP) to evaluate the phosphorylation of the insulin receptor substrate-1 (IRS1), Protein kinase B (AKT), and JNK in the hypothalamus. Single LPS increased the expression of pIRS1, pAKT, and pJNK, whereas the repeated LPS treatment failed to recruit pIRS1 and pAKT. The 6 LPS treated rats showed increased total JNK and pJNK. The 6 LPS rats became unresponsive to the hypophagic effect induced by central insulin administration (12 μM/5 μL, ICV). Prolonged exposure to LPS (24 h) impaired the insulin-induced AKT phosphorylation and the translocation of the transcription factor forkhead box protein O1 (FoxO1) from the nucleus to the cytoplasm of the cultured hypothalamic GT1-7 cells. Central administration of the JNK inhibitor (20 μM/5 μL, ICV) restored the ability of insulin to phosphorylate IRS1 and AKT in 6 LPS rats. The present data suggest that an increased JNK activity in the hypothalamus underlies the development of insulin resistance during prolonged exposure to endotoxins. Our study reveals that weight gain is not mandatory for the development of hypothalamic insulin resistance and the blockade of proinflammatory pathways could be useful for restoring the insulin signaling during prolonged low-grade inflammation as seen in obesity.

Lunar power system summary of studies for the lunar enterprise task force NASA-office of exploration

NASA Technical Reports Server (NTRS)

Criswell, David R.

1989-01-01

The capacity of global power systems must be increased by a factor of ten to provide the predicted power needs of electric power by the year 2050. The Lunar Power System (LPS) would collect solar energy at power bases located on opposing limbs of the moon as seen from Earth. LPS can provide dependable, economic, renewable, and environmentally benign solar energy to Earth. A preliminary engineering and cash flow model of the LPS was developed. Results are shown for a system scaled to a peak capacity of 355 GWe on Earth and to provide 13,600 GWe-Yrs of energy over a 70 year life cycle of construction and full operation. The growth in capacity of the reference system from start of installation on the moon in 2005 to completion of its nominal life cycle in the year 2070 is shown. World needs for power could be accommodated by expansion in capacity of the reference LPS beyond 344 GWe. This would be done by steadily incorporating newer technology during full operation and by establishing additional bases. The results presented encourage consideration of a faster paced program than is assumed herein.

Effects of Coffee Extracts with Different Roasting Degrees on Antioxidant and Anti-Inflammatory Systems in Mice.

PubMed

Choi, Sukyoung; Jung, Soohan; Ko, Kwang Suk

2018-03-16

Coffee roasting affects the taste, color, and aroma of coffee. The Maillard reaction, a major reaction during the roasting process, produces melanoidin, which affects the overall antioxidant capacity and anti-inflammatory effects of coffee. In this experiment, coffee roasting was divided into four degrees: Light, Medium, City, and French. To examine the in vivo antioxidant and anti-inflammatory effects of coffee extracts with different roasting degrees, we used 10-week-old male C57BL/6 mice. Mice were pre-treated with coffee extracts for 10 days by oral gavage (300 mg/Kg.B.W). After the last pre-treatment, lipopolysaccharide (LPS, 15 mg/Kg.B.W) was injected intraperitoneally for immune stimulation. Histopathological analysis showed that hepatic portal vein invasion and liver necrosis were severe in the LPS-treated group. However, these phenomena were greatly ameliorated when mice were pre-treated with Light- or Medium-roasted coffee extracts. Hepatic glutathione level was increased in the French group but decreased in the LPS-stimulated group. When mice were treated with LPS, mRNA expression level of tumor necrosis factor-alpha (TNF-α) was increased, whereas TNF-α expression was significantly reduced in the Light and Medium groups. Treatment with coffee extracts decreased the mRNA expression levels of interleukin 6 (IL-6) in mice stimulated by LPS, regardless of coffee roasting degrees. These effects decreased with the increasing coffee roasting degree. Results of luciferase reporter assay revealed that these effects of coffee extracts were transcriptionally regulated by the NF-κB pathway. Taken together, these results suggest that the roasting degree affects the antioxidant and anti-inflammatory effects of coffee extracts.

Molecular cloning and analysis of the ergopeptine assembly system in the ergot fungus Claviceps purpurea.

PubMed

Correia, Telmo; Grammel, Nicolas; Ortel, Ingo; Keller, Ullrich; Tudzynski, Paul

2003-12-01

Claviceps purpurea produces the pharmacological important ergopeptines, a class of cyclol-structured alkaloid peptides containing D-lysergic acid. These compounds are assembled from D-lysergic acid and three different amino acids by the nonribosomal peptide synthetase enzymes LPS1 and LPS2. Cloning of alkaloid biosynthesis genes from C. purpurea has revealed a gene cluster including two NRPS genes, cpps 1 and cpps 2. Protein sequence data had assigned earlier cpps1 to encode the trimodular LPS1 assembling the tripeptide portion of ergopeptines. Here, we show by transcriptional analysis, targeted inactivation, analysis of disruption mutants, and heterologous expression that cpps 2 encodes the monomodular LPS2 responsible for D-lysergic acid activation and incorporation into the ergopeptine backbone. The presence of two distinct NRPS subunits catalyzing formation of ergot peptides is the first example of a fungal NRPS system consisting of different NRPS subunits.

Cannabinoid Receptor Type 1 Agonist ACEA Protects Neurons from Death and Attenuates Endoplasmic Reticulum Stress-Related Apoptotic Pathway Signaling.

PubMed

Vrechi, Talita A; Crunfli, Fernanda; Costa, Andressa P; Torrão, Andréa S

2018-05-01

Neurodegeneration is the result of progressive destruction of neurons in the central nervous system, with unknown causes and pathological mechanisms not yet fully elucidated. Several factors contribute to neurodegenerative processes, including neuroinflammation, accumulation of neurotoxic factors, and misfolded proteins in the lumen of the endoplasmic reticulum (ER). Endocannabinoid signaling has been pointed out as an important modulatory system in several neurodegeneration-related processes, inhibiting the inflammatory response and increasing neuronal survival. Thus, we investigated the presumptive protective effect of the selective cannabinoid type 1 (CB1) receptor agonist arachidonyl-2'-chloroethylamide (ACEA) against inflammatory (lipopolysaccharide, LPS) and ER stress (tunicamycin) stimuli in an in vitro neuronal model (Neuro-2a neuroblastoma cells). Cell viability analysis revealed that ACEA was able to protect against cell death induced by LPS and tunicamycin. This neuroprotective effect occurs via the CB1 receptor in the inflammation process and via the transient receptor potential of vanilloid type-1 (TRPV1) channel in ER stress. Furthermore, the immunoblotting analyses indicated that the neuroprotective effect of ACEA seems to involve the modulation of eukaryotic initiation factor 2 (eIF2α), transcription factor C/EBP homologous protein (CHOP), and caspase 12, as well as the survival/death p44/42 MAPK, ERK1/2-related signaling pathways. Together, these data suggest that the endocannabinoid system is a potential therapeutic target in neurodegenerative processes, especially in ER-related neurodegenerative diseases.

Effects of mannan oligosaccharide on cytokine secretions by porcine alveolar macrophages and serum cytokine concentrations in nursery pigs.

PubMed

Che, T M; Johnson, R W; Kelley, K W; Dawson, K A; Moran, C A; Pettigrew, J E

2012-02-01

This study explored the hypothesis that mannan oligosaccharide (MOS) acts to reduce systemic inflammation in pigs by evaluating cytokine production of alveolar macrophages (AM) and serum cytokine concentrations. A total of 160 pigs were fed diets containing 0.2 or 0.4% MOS for 2 or 4 wk postweaning compared with control diets without MOS. Dietary MOS did not affect the serum concentration of tumor necrosis factor (TNF)-α and tended (P = 0.081) to increase that of IL-10. These cytokine concentrations also changed over time (P < 0.001). After 2-wk feeding of the control or MOS diets, AM were collected and stimulated ex vivo with lipopolysaccharide (LPS) or polyinosinic:polycytidylic acid (PLIC) as infection models. The LPS-stimulated AM from MOS-fed pigs (n = 12) secreted less TNF-α (P < 0.001) and more IL-10 (P = 0.026) than those from control-fed pigs (n = 6). However, dietary MOS had less effect on ex vivo TNF-α and IL-10 production by PLIC-stimulated AM (P = 0.091 and P > 0.10, respectively. Further, effects of MOS were examined in 4 in vitro experiments. In Exp. 1 (n = 4 pigs), MOS and mannan-rich fraction (MRF), when added to AM cultures, were able to increase TNF-α production. This direct effect of MOS was not due to endotoxin contamination as verified in Exp. 2 (n = 6 pigs) using polymyxin B, an inhibitor of LPS activation of toll-like receptor 4. Polymyxin B inhibited production of TNF-α by AM after treatment with LPS (P < 0.001), but not after treatment with MOS in the absence of LPS (P > 0.70). In Exp. 3 (n = 6 pigs), when MOS was directly applied in vitro, the pattern of cytokine production by LPS-activated AM was similar to that observed ex vivo, as MOS suppressed LPS-induced TNF-α (P < 0.001) and enhanced LPS-induced IL-10 (P = 0.028). In Exp. 4 (n = 6 pigs), when MRF replaced MOS, AM-produced TNF-α induced by LPS or PLIC was suppressed by MRF (P = 0.015 or P < 0.001, respectively). These data establish that MOS and MRF suppress LPS-induced TNF-α secretions by AM. Generally, the study suggests that MOS may be a potent immunomodulator because it directly activates AM to secrete TNF-α and alters the cytokine responses of bacterial endotoxin-induced AM in both ex vivo and in vitro systems. In particular, feeding MOS to pigs for 2 wk reduces TNF-α and increases IL-10 concentrations after ex vivo treatment of AM with LPS. These immunomodulatory properties of MOS may have important implications for both host defense and avoidance of harmful overstimulation of the immune system.

Unit Testing and Remote Display Development

NASA Technical Reports Server (NTRS)

Costa, Nicholas

2014-01-01

The Kennedy Space Center is currently undergoing an extremely interesting transitional phase. The final Space Shuttle mission, STS-135, was completed in July of 2011. NASA is now approaching a new era of space exploration. The development of the Orion Multi- Purpose Crew Vehicle (MPCV) and the Space Launch System (SLS) launch vehicle that will launch the Orion are currently in progress. An important part of this transition involves replacing the Launch Processing System (LPS) which was previously used to process and launch Space Shuttles and their associated hardware. NASA is creating the Spaceport Command and Control System (SCCS) to replace the LPS. The SCCS will be much simpler to maintain and improve during the lifetime of the spaceflight program that it will support. The Launch Control System (LCS) is a portion of the SCCS that will be responsible for launching the rockets and spacecraft. The Integrated Launch Operations Applications (ILOA) group of SCCS is responsible for creating displays and scripts, both remote and local, that will be used to monitor and control hardware and systems needed to launch a spacecraft. It is crucial that the software contained within be thoroughly tested to ensure that it functions as intended. Unit tests must be written in Application Control Language (ACL), the scripting language used by LCS. These unit tests must ensure complete code coverage to safely guarantee there are no bugs or any kind of issue with the software.

Proteinaceous determinants of surface colonization in bacteria: bacterial adhesion and biofilm formation from a protein secretion perspective

PubMed Central

Chagnot, Caroline; Zorgani, Mohamed A.; Astruc, Thierry; Desvaux, Mickaël

2013-01-01

Bacterial colonization of biotic or abiotic surfaces results from two quite distinct physiological processes, namely bacterial adhesion and biofilm formation. Broadly speaking, a biofilm is defined as the sessile development of microbial cells. Biofilm formation arises following bacterial adhesion but not all single bacterial cells adhering reversibly or irreversibly engage inexorably into a sessile mode of growth. Among molecular determinants promoting bacterial colonization, surface proteins are the most functionally diverse active components. To be present on the bacterial cell surface, though, a protein must be secreted in the first place. Considering the close association of secreted proteins with their cognate secretion systems, the secretome (which refers both to the secretion systems and their protein substrates) is a key concept to apprehend the protein secretion and related physiological functions. The protein secretion systems are here considered in light of the differences in the cell-envelope architecture between diderm-LPS (archetypal Gram-negative), monoderm (archetypal Gram-positive) and diderm-mycolate (archetypal acid-fast) bacteria. Besides, their cognate secreted proteins engaged in the bacterial colonization process are regarded from single protein to supramolecular protein structure as well as the non-classical protein secretion. This state-of-the-art on the complement of the secretome (the secretion systems and their cognate effectors) involved in the surface colonization process in diderm-LPS and monoderm bacteria paves the way for future research directions in the field. PMID:24133488

Selol, an organic selenium donor, prevents lipopolysaccharide-induced oxidative stress and inflammatory reaction in the rat brain.

PubMed

Dominiak, Agnieszka; Wilkaniec, Anna; Jęśko, Henryk; Czapski, Grzegorz A; Lenkiewicz, Anna M; Kurek, Eliza; Wroczyński, Piotr; Adamczyk, Agata

2017-09-01

Neuroinflammation and oxidative stress are key intertwined pathological factors in many neurological, particularly neurodegenerative diseases, such as Alzheimer's and Parkinson's disorders as well as autism. The present study was conducted to evaluate the protective effects of Selol, an organic selenium donor, against lipopolysaccharide (LPS)-mediated inflammation in rat brain. The results demonstrated that the peripheral administration of LPS in a dose of 100 μg/kg b.w. evoked typical pathological reaction known as systemic inflammatory response. Moreover, we observed elevated blood levels of thiobarbituric acid-reactive substances (TBARS), a marker of oxidative stress, as well as increased concentration of tumor necrosis factor-α (TNF-α) in LPS-treated animals. Selol significantly prevented these LPS-evoked changes. Subsequently, Selol protected against LPS-induced up-regulation of proinflammatory cytokines (Tnfa, Ifng, Il6) in rat brain cortex. The molecular mechanisms through which Selol prevented the neuroinflammation were associated with the inhibition of oxidized glutathione (GSSG) accumulation and with an increase of glutathione-associated enzymes: glutathione peroxidase (Se-GPx), glutathione reductase (GR) as well as thioredoxin reductase (TrxR) activity and expression. Finally, we observed that Selol administration effectively protected against LPS-induced changes in the expression of brain-derived neurotrophic factor (Bdnf). In conclusion, our studies indicated that Selol effectively protects against LPS-induced neuroinflammation by inhibiting pro-inflammatory cytokine release, by boosting antioxidant systems, and by augmenting BDNF level. Therefore, Selol could be a multi-potent and effective drug useful in the treatment and prevention of brain disorders associated with neuroinflammation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Knowledge representation and user interface concepts to support mixed-initiative diagnosis

NASA Technical Reports Server (NTRS)

Sobelman, Beverly H.; Holtzblatt, Lester J.

1989-01-01

The Remote Maintenance Monitoring System (RMMS) provides automated support for the maintenance and repair of ModComp computer systems used in the Launch Processing System (LPS) at Kennedy Space Center. RMMS supports manual and automated diagnosis of intermittent hardware failures, providing an efficient means for accessing and analyzing the data generated by catastrophic failure recovery procedures. This paper describes the design and functionality of the user interface for interactive analysis of memory dump data, relating it to the underlying declarative representation of memory dumps.

Krill Oil-In-Water Emulsion Protects against Lipopolysaccharide-Induced Proinflammatory Activation of Macrophages In Vitro

PubMed Central

Bonaterra, Gabriel A.; Driscoll, David; Schwarzbach, Hans; Kinscherf, Ralf

2017-01-01

Background: Parenteral nutrition is often a mandatory therapeutic strategy for cases of septicemia. Likewise, therapeutic application of anti-oxidants, anti-inflammatory therapy, and endotoxin lowering, by removal or inactivation, might be beneficial to ameliorate the systemic inflammatory response during the acute phases of critical illness. Concerning anti-inflammatory properties in this setting, omega-3 fatty acids of marine origin have been frequently described. This study investigated the anti-inflammatory and LPS-inactivating properties of krill oil (KO)-in-water emulsion in human macrophages in vitro. Materials and Methods: Differentiated THP-1 macrophages were activated using specific ultrapure-LPS that binds only on the toll-like receptor 4 (TLR4) in order to determine the inhibitory properties of the KO emulsion on the LPS-binding capacity, and the subsequent release of TNF-α. Results: KO emulsion inhibited the macrophage binding of LPS to the TLR4 by 50% (at 12.5 µg/mL) and 75% (at 25 µg/mL), whereas, at 50 µg/mL, completely abolished the LPS binding. Moreover, KO (12.5 µg/mL, 25 µg/mL, or 50 µg/mL) also inhibited (30%, 40%, or 75%, respectively) the TNF-α release after activation with 0.01 µg/mL LPS in comparison with LPS treatment alone. Conclusion: KO emulsion influences the LPS-induced pro-inflammatory activation of macrophages, possibly due to inactivation of the LPS binding capacity. PMID:28294970

Biophysical Mechanisms of Endotoxin Neutralization by Cationic Amphiphilic Peptides

PubMed Central

Kaconis, Yani; Kowalski, Ina; Howe, Jörg; Brauser, Annemarie; Richter, Walter; Razquin-Olazarán, Iosu; Iñigo-Pestaña, Melania; Garidel, Patrick; Rössle, Manfred; Martinez de Tejada, Guillermo; Gutsmann, Thomas; Brandenburg, Klaus

2011-01-01

Bacterial endotoxins (lipopolysaccharides (LPS)) are strong elicitors of the human immune system by interacting with serum and membrane proteins such as lipopolysaccharide-binding protein (LBP) and CD14 with high specificity. At LPS concentrations as low as 0.3 ng/ml, such interactions may lead to severe pathophysiological effects, including sepsis and septic shock. One approach to inhibit an uncontrolled inflammatory reaction is the use of appropriate polycationic and amphiphilic antimicrobial peptides, here called synthetic anti-LPS peptides (SALPs). We designed various SALP structures and investigated their ability to inhibit LPS-induced cytokine secretion in vitro, their protective effect in a mouse model of sepsis, and their cytotoxicity in physiological human cells. Using a variety of biophysical techniques, we investigated selected SALPs with considerable differences in their biological responses to characterize and understand the mechanism of LPS inactivation by SALPs. Our investigations show that neutralization of LPS by peptides is associated with a fluidization of the LPS acyl chains, a strong exothermic Coulomb interaction between the two compounds, and a drastic change of the LPS aggregate type from cubic into multilamellar, with an increase in the aggregate sizes, inhibiting the binding of LBP and other mammalian proteins to the endotoxin. At the same time, peptide binding to phospholipids of human origin (e.g., phosphatidylcholine) does not cause essential structural changes, such as changes in membrane fluidity and bilayer structure. The absence of cytotoxicity is explained by the high specificity of the interaction of the peptides with LPS. PMID:21641310

Stimulation of interleukin-1 beta production of human dental pulp cells by Porphyromonas endodontalis lipopolysaccharide.

PubMed

Hosoya, S; Matsushima, K

1997-01-01

IL-1 beta is synthesized as an inactive precursor, which is subsequently processed by IL-1 beta converting enzyme (ICE) and found extracellularly as a mature biologically active polypeptide. Also, IL-1 beta has been detected in necrotic and inflamed dental pulp. We examined the IL-1 beta production in human dental pulp (HDP) cells treated with lipopolysaccharide (LPS) from Porphyromonas endodontalis (P. e.) isolated from root canals and radicular cyst fluids. We demonstrated that P. e. LPS stimulated IL-1 beta release from HDP cells in a time- and dose-dependent manner. However, ICE activity was not increased by P. e. LPS. Northern blot hybridization analysis revealed that the IL-1 beta mRNA level in HDP cells was increased by P. e. LPS. These results suggest that stimulation of IL-1 beta release from HDP cells by P. e. LPS may have an important role in the progression of inflammation in pulpal and periapical disease.

Intestinal alkaline phosphatase detoxifies lipopolysaccharide and prevents inflammation in zebrafish in response to the gut microbiota.

PubMed

Bates, Jennifer M; Akerlund, Janie; Mittge, Erika; Guillemin, Karen

2007-12-13

Vertebrates harbor abundant lipopolysaccharide (LPS) in their gut microbiota. Alkaline phosphatases can dephosphorylate and detoxify the endotoxin component of LPS. Here, we show that expression of the zebrafish intestinal alkaline phosphatase (Iap), localized to the intestinal lumen brush border, is induced during establishment of the gut microbiota. Iap-deficient zebrafish are hypersensitive to LPS toxicity and exhibit the excessive intestinal neutrophil influx characteristic of wild-type zebrafish exposed to LPS. Both of these Iap mutant phenotypes are dependent on Myd88 and Tumor Necrosis Factor Receptor (Tnfr), proteins also involved in LPS sensitivity in mammals. When reared germ-free, the intestines of Iap-deficient zebrafish are devoid of neutrophils. Together, these findings demonstrate that the endogenous microbiota establish the normal homeostatic level of neutrophils in the zebrafish intestine through a process involving Iap, Myd88, and Tnfr. Thus, by preventing inflammatory responses, Iap plays a crucial role in promoting mucosal tolerance to resident gut bacteria.

The Nuclear Orphan Receptor NR4A1 is Involved in the Apoptotic Pathway Induced by LPS and Simvastatin in RAW 264.7 Macrophages.

PubMed

Kim, Yong Chan; Song, Seok Bean; Lee, Sang Kyu; Park, Sang Min; Kim, Young Sang

2014-04-01

Macrophage death plays a role in several physiological and inflammatory pathologies such as sepsis and arthritis. In our previous work, we showed that simvastatin triggers cell death in LPS-activated RAW 264.7 mouse macrophage cells through both caspase-dependent and independent apoptotic pathways. Here, we show that the nuclear orphan receptor NR4A1 is involved in a caspase-independent apoptotic process induced by LPS and simvastatin. Simvastatin-induced NR4A1 expression in RAW 264.7 macrophages and ectopic expression of a dominant-negative mutant form of NR4A1 effectively suppressed both DNA fragmentation and the disruption of mitochondrial membrane potential (MMP) during LPS- and simvastatin-induced apoptosis. Furthermore, apoptosis was accompanied by Bcl-2-associated X protein (Bax) translocation to the mitochondria. Our findings suggest that NR4A1 expression and mitochondrial translocation of Bax are related to simvastatin-induced apoptosis in LPS-activated RAW 264.7 macrophages.

Nuclear translocation of the transcription factor STAT3 in the guinea pig brain during systemic or localized inflammation

PubMed Central

Rummel, Christoph; Hübschle, Thomas; Gerstberger, Rüdiger; Roth, Joachim

2004-01-01

The purpose of the present study was to investigate a possible lipopolysaccharide (LPS)-induced activation of brain cells that is mediated by the pleiotropic cytokine interleukin-6 (IL-6) and its transcription factor STAT3 during systemic or localized inflammation. In guinea pigs, intra-arterial (i.a., 10 μg kg−1) or intraperitoneal (i.p., 30 μg kg−1) injections of bacterial LPS cause a systemic inflammatory response which is accompanied by a robust fever. A febrile response can also be induced by administration of LPS into artificial subcutaneously implanted Teflon chambers (s.c. 100 or 10 μg kg−1), which reflects an experimental model that mimics local tissue inflammation. Baseline plasma levels of bioactive IL-6 determined 60 min prior to injections of LPS or vehicle amounted to 35–80 international units (i.u.) ml−1. Within 90 min of LPS injection, plasma IL-6 rose about 1000-fold in the groups injected i.a. or i.p., about 50-fold in the group injected s.c. with 100 μg kg−1 LPS, and only 5-fold in guinea pigs injected with the lower dose of LPS (10 μg kg−1). At this time point, a distinct nuclear translocation pattern of the transcription factor STAT3 became evident in several brain structures. Amongst those, the sensory circumventricular organs known to lack a tight blood—brain barrier such as the area postrema, the vascular organ of the lamina terminalis and the subfornical organ, as well as the hypothalamic supraoptic nucleus showed intense nuclear STAT3 signals in the i.a. or i.p. injected groups. In contrast a moderate (s.c. group, 100 μg kg−1), or even no (s.c. group, 10 μg kg−1), nuclear STAT3 translocation occurred in response to s.c. injections of LPS. These results suggest that STAT3-mediated genomic activation of target gene transcription in brain cells occurred only in those cases in which sufficiently high concentrations of circulating IL-6 were formed during systemic (i.a.. and i.p. groups) or localized (s.c. group, 100 μg kg−1) inflammation. PMID:14966301

Functional anatomy of the levator palpebrae superioris muscle and its connective tissue system.

PubMed Central

Ettl, A; Priglinger, S; Kramer, J; Koornneef, L

1996-01-01

AIMS/BACKGROUND: The connective tissue system of the levator palpebrae superioris muscle (LPS) consists of the septa surrounding its muscle sheath, the superior transverse ligament (STL) commonly referred to as 'Whitnall's ligament' and the common sheath which is the fascia between the LPS and the superior rectus muscle (SRM). The anterior band-like component of the common sheath is called transverse superior fascial expansion (TSFE) of the SRM and LPS. It mainly extends from the connective tissue of the trochlea to the fascia of the lacrimal gland. A detailed description of the relation between the LPS and its connective tissue is presented. Furthermore, the course of the LPS in the orbit is described. The study was conducted to provide a morphological basis for biomechanical and clinical considerations regarding ptosis surgery. METHODS: Postmortem dissections were performed in 16 orbits from eight cadavers. The microscopical anatomy was demonstrated in six formalin preserved orbits from six cadavers which had been sectioned in the frontal and sagittal plane and stained with haematoxylin and azophloxin. Surface coil magnetic resonance imaging in the sagittal and coronal plane was performed in five orbits from five normal volunteers using a T1 weighted spin echo sequence. RESULTS: The STL and the TSFE surround the LPS to form a fascial sleeve around the muscle which has attachments to the medial and lateral orbital wall. The TSFE, which is thicker than the STL, blends with Tenon's capsule. The STL and the fascial sheath of the LPS muscle are suspended from the orbital roof by a framework of radial connective tissue septa. MR images show that the TSFE is located between the anterior third of the superior rectus muscle and the segment of the LPS muscle where it changes its course from upwards to downwards. In this area, the LPS reaches its highest point in the orbit (culmination point). The culmination point is located a few millimetres posterior to the equator and superior to the globe. CONCLUSION: Whitnall's ligament can be considered to consist of two distinct parts--the TSFE inferior to the LPS and the STL superior to the LPS. Since the medial and lateral main attachments of Whitnall's ligament are situated inferior to the level of the culmination point of the LPS, the ligament itself is unlikely to suspend the levator muscle. However, a suspension of the LPS may be achieved by the radial connective tissue septa of the superior orbit. The TSFE in connection with the globe may have an additional supporting function. The elasticity of Whitnall's ligament and its connections with highly elastic structures including Tenon's capsule, may provide the morphological substrate for the previously proposed passive (that is, without orbicularis action) lowering of the lid during downward saccades. Images PMID:8949713

Cocaine counteracts LPS-induced hypolocomotion and triggers locomotor sensitization expression.

PubMed

Tortorelli, Lucas Silva; Engelke, Douglas Senna; Lunardi, Paula; Mello E Souza, Tadeu; Santos-Junior, Jair Guilherme; Gonçalves, Carlos-Alberto

2015-01-01

Neuroimmune signalling underlies addiction and comorbid depression. Clinical observations indicate that infections and chronic lesions are more frequent in drug users and elevated inflammatory states are evident in cocaine dependents. Therefore, lipopolysaccharide (LPS) and inflammatory cytokines represent an important tool for the investigation of sickness, depressive illness and addiction behaviour. A major component of addiction is the progressive and persistent increase in locomotor activity after repeated drug administration and even prolonged periods of abstinence. The aim of this study was to investigate the response of locomotor sensitization when a non-sensitizing dose of cocaine is paired with a systemic inflammatory stimulus. LPS and cocaine were administered intraperitonealy in young-adult male C57bl/6 mice during a 5-day acquisition phase. After a 48-h withdrawal period all groups were challenged with cocaine to evaluate locomotor expression. During the acquisition phase, the LPS-treated groups displayed characteristic hypolocomotion related to sickness behaviour. The low dose of cocaine did not increase the distance travelled, characterizing a non-sensitization dose. Groups that received both LPS and cocaine did not display hypolocomotion, indicating that cocaine might counteract hypolocomotion sickness behaviour. Moreover, during challenge, only these animals expressed locomotor sensitization. Our results indicate that LPS could facilitate the expression of locomotor sensitization in mice and that the immune system may modulate cocaine-induced sensitization. Copyright © 2015 Elsevier B.V. All rights reserved.

Endogenous hydrogen sulfide regulates histone demethylase JMJD3-mediated inflammatory response in LPS-stimulated macrophages and in a mouse model of LPS-induced septic shock.

PubMed

Liu, Siyu; Wang, Xiling; Pan, Lilong; Wu, Weijun; Yang, Di; Qin, Ming; Jia, Wanwan; Xiao, Chenxi; Long, Fen; Ge, Junbo; Liu, Xinhua; Zhu, YiZhun

2018-03-01

Overproduction of inflammatory mediators contributes to uncontrolled inflammation during endotoxin shock. Cystathionine-γ-lyase (CSE), an enzyme involved in hydrogen sulfide (H 2 S) biosynthesis, has potential anti-inflammatory activity in a variety of inflammatory diseases. Jumonji domain-containing protein 3 (JMJD3), a histone 3 Lys27 (H3K27) demethylase, has been implicated in macrophage activation, but its function in CSE-mediated anti-inflammatory activities remains unknown. In the present study CSE was found to be upregulated in macrophages and mouse lipopolysaccharide (LPS) challenge models. LPS stimulation also enhanced the activation of JMJD3 and decreased H3K27me3 levels. JMJD3 knockdown upregulated H3K27me3 levels and attenuated the LPS-mediated inflammatory response. CSE knockout amplified the inflammatory cascade by increasing JMJD3 expression in septic mice. Similarly, enhanced production of inflammatory mediators by macrophages was mitigated by CSE overexpression via inhibition of JMJD3 expression. This is the first report indicating that inflammation enhanced CSE/H 2 S system biosynthesis, that in turn attenuated the LPS-triggered inflammatory response by regulating JMJD3 expression. Thus, the CSE/H 2 S system represents an epigenetic-based modification mechanism to prevent uncontrolled inflammation. Copyright © 2017 Elsevier Inc. All rights reserved.

Caffeic acid attenuates lipopolysaccharide-induced sickness behaviour and neuroinflammation in mice.

PubMed

Basu Mallik, Sanchari; Mudgal, Jayesh; Nampoothiri, Madhavan; Hall, Susan; Dukie, Shailendra Anoopkumar-; Grant, Gary; Rao, C Mallikarjuna; Arora, Devinder

2016-10-06

Accumulating data links inflammation, oxidative stress and immune system in the pathophysiology of major depressive disorders. Sickness behaviour is a set of behavioural changes that develop during infection, eventually leading to decrease in mobility and depressed behaviour. Lipopolysaccharide (LPS) induces a depression-like state in animals that mimics sickness behaviour. Caffeic acid, a naturally occurring polyphenol, possesses antioxidant and anti-inflammatory properties. The present study was designed to explore the potential of caffeic acid against LPS-induced sickness behaviour in mice. Caffeic acid (30mg/kg) and imipramine (15mg/kg) were administered orally one hour prior to LPS (1.5mg/kg) challenge. Behavioural assessment was carried out between 1 and 2h and blood samples were collected at 3h post-LPS injection. Additionally, cytokines (brain and serum) and brain oxidative stress markers were estimated. LPS increased the systemic and brain cytokine levels, altered the anti-oxidant defence and produced key signs of sickness behaviour in animals. Caffeic acid treatment significantly reduced the LPS-induced changes, including reduced expression of inflammatory markers in serum and whole brain. Caffeic acid also exerted an anti-oxidant effect, which was evident from the decreased levels of oxidative stress markers in whole brain. Our data suggests that caffeic acid can prevent the neuroinflammation-induced acute and probably the long term neurodegenerative changes. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The Vibrio cholerae VprA-VprB Two-Component System Controls Virulence Through Endotoxin Modification

DTIC Science & Technology

2014-12-23

antimicrobial peptides of the innate immune system bind to the membrane of Gram-negative pathogens via conserved, surface-exposed lipopolysaccharide (LPS... antimicrobial peptide polymyxin. However, the regulatory mechanisms of lipid A modification in V. 1. REPORT DATE (DD-MM-YYYY) 4. TITLE AND SUBTITLE...12211 Research Triangle Park, NC 27709-2211 bacterial cell surface, host immune system, cationic antimicrobial peptides , lipid A, LPS REPORT

Goats without Prion Protein Display Enhanced Proinflammatory Pulmonary Signaling and Extracellular Matrix Remodeling upon Systemic Lipopolysaccharide Challenge.

PubMed

Salvesen, Øyvind; Reiten, Malin R; Kamstra, Jorke H; Bakkebø, Maren K; Espenes, Arild; Tranulis, Michael A; Ersdal, Cecilie

2017-01-01

A naturally occurring mutation in the PRNP gene of Norwegian dairy goats terminates synthesis of the cellular prion protein (PrP C ), rendering homozygous goats ( PRNP Ter/Ter ) devoid of the protein. Although PrP C has been extensively studied, particularly in the central nervous system, the biological role of PrP C remains incompletely understood. Here, we examined whether loss of PrP C affects the initial stage of lipopolysaccharide (LPS)-induced acute lung injury (ALI). Acute pulmonary inflammation was induced by intravenous injection of LPS ( Escherichia coli O26:B6) in 16 goats (8 PRNP Ter/Ter and 8 PRNP +/+ ). A control group of 10 goats (5 PRNP Ter/Ter and 5 PRNP +/+ ) received sterile saline. Systemic LPS challenge induced sepsis-like clinical signs including tachypnea and respiratory distress. Microscopic examination of lungs revealed multifocal areas with alveolar hemorrhages, edema, neutrophil infiltration, and higher numbers of alveolar macrophages, with no significant differences between PRNP genotypes. A total of 432 ( PRNP +/+ ) and 596 ( PRNP Ter/Ter ) genes were differentially expressed compared with the saline control of the matching genotype. When assigned to gene ontology categories, biological processes involved in remodeling of the extracellular matrix (ECM), were exclusively enriched in PrP C -deficient goats. These genes included a range of collagen-encoding genes, and proteases such as matrix metalloproteinases ( MMP1, MMP2, MMP14, ADAM15 ) and cathepsins. Several proinflammatory upstream regulators (TNF-α, interleukin-1β, IFN-γ) showed increased activation scores in goats devoid of PrP C . In conclusion, LPS challenge induced marked alterations in the lung tissue transcriptome that corresponded with histopathological and clinical findings in both genotypes. The increased activation of upstream inflammatory regulators and enrichment of ECM components could reflect increased inflammation in the absence of PrP C . Further studies are required to elucidate whether these alterations may affect the later reparative phase of ALI.

Pseudomonas aeruginosa lipopolysaccharide induces CF-like alteration of protein secretion by human tracheal gland cells.

PubMed

Kammouni, W; Figarella, C; Baeza, N; Marchand, S; Merten, M D

1997-12-18

Human tracheal gland (HTG) serous cells are now believed to play a major role in the physiopathology of cystic fibrosis. Because of the persistent inflammation and the specific infection by Pseudomonas aeruginosa in the lung, we looked for the action of the lipopolysaccharide (LPS) of this bacteria on human tracheal gland cells in culture by studying the secretion of the secretory leukocyte proteinase inhibitor (SLPI) which is a specific serous secretory marker of these cells. Treatment with Pseudomonas aeruginosa LPS resulted in a significant dose-dependent increase in the basal production of SLPI (+ 250 +/- 25%) whilst the SLPI transcript mRNA levels remained unchanged. This LPS-induced increase in secretion was inhibited by glucocorticoides. Furthermore, LPS treatment of HTG cells induces a loss of responsiveness to carbachol and isoproterenol but not to adenosine triphosphate. These findings indicate that HTG cells treated by Pseudomonas aeruginosa LPS have the same behavior as those previously observed with CF-HTG cells. Exploration by using reverse transcriptase polymerase chain reaction amplification showed that LPS downregulated cystic fibrosis transmembrane conductance regulator (CFTR) mRNA expression in HTG cells indicative of a link between CFTR function and consequent CF-like alteration in protein secretory process.

Magnolol pretreatment prevents sepsis-induced intestinal dysmotility by maintaining functional interstitial cells of Cajal.

PubMed

Miao, Bin; Zhang, Shuwen; Wang, Hong; Yang, Tiecheng; Zhou, Deshan; Wang, Bao-en

2013-08-01

The purpose of this study was to investigate the mechanism by which magnolol treatment prevents lipopolysaccharide (LPS)-induced septic dysmotility in mice. Sepsis was induced by intravenous tail vein injection of LPS (4 mg/kg body weight). Animals were divided into three groups: the magnolol-treated septic group, the placebo-treated septic group, and the control group. Intestinal transit and circular smooth muscle contraction were measured 12 h after LPS injection, and immunocytochemisty was performed to study the morphology of interstitial cells of Cajal (ICCs). Stem cell factor (SCF) expression and c-kit phosphorylation were determined by Western blot analysis, and the mRNA levels of inducible NO synthase (iNOS) were determined by RT-PCR. Nitric oxide (NO) content, superoxide dismutase (SOD) activity, and malondialdehyde (MDA) concentration were detected using commercial kits. Intestinal transit and muscular contractility were significantly lower in the LPS-treated group than in the control group. Immunocytochemical experiments showed that the total number of ICCs, and the total and average lengths of the ICC processes were significantly decreased in the LPS-treated group compared with those in the control group. In LPS-treated animals, magnolol pretreatment significantly accelerated intestinal transit, increased circular muscle contraction, and prevented ICC morphology changes. Phosphorylation of c-kit and expression of SCF were significantly downregulated in LPS-treated animals compared with control animals. Magnolol pretreatment prevented sepsis-induced decreases in c-kit phosphorylation and SCF expression in LPS-treated animals. Magnolol pretreatment prevented the sepsis-induced increase in NO concentration, iNOS expression, and MDA concentration, and decrease in SOD activity in LPS-treated animals. Our results suggest that magnolol treatment prevents sepsis-induced intestinal dysmotility by regulating SCF/c-kit and NO signaling to maintain functional ICCs.

TRIB3 mediates the expression of Wnt5a and activation of nuclear factor-κB in Porphyromonas endodontalis lipopolysaccharide-treated osteoblasts.

PubMed

Yu, Y; Qiu, L; Guo, J; Yang, D; Qu, L; Yu, J; Zhan, F; Xue, M; Zhong, M

2015-08-01

Porphyromonas endodontalis lipopolysaccharide (LPS) is considered to be correlated with the progression of bone resorption in periodontal and periapical diseases. Wnt5a has recently been implicated in inflammatory processes, but its role is unclear as a P. endodontalis LPS-induced mediator in osteoblasts. Tribbles homolog 3 (TRIB3) encodes a pseudokinase and has been linked to inflammation in certain situations. Here, we found that P. endodontalis LPS induced Wnt5a expression in a dose- and time-dependent manner and it also upregulated translocation, phosphorylation and transcriptional activity of nuclear factor-κB (NF-κB) in MC3T3-E1 cells. Bay 11-7082 blocked the translocation of NF-κB and Wnt5a expression induced by P. endodontalis LPS. Chromatin immunoprecipitation assay further established that induction of Wnt5a by P. endodontalis LPS was mediated through the NF-κB p65 subunit. Additionally, P. endodontalis LPS increased expression of TRIB3 in osteoblasts after 10 h simulated time. Overexpression of TRIB3 enhanced NF-κB phosphorylation and Wnt5a induction, whereas knockdown of TRIB3 inhibited NF-κB phosphorylation and Wnt5a expression in P. endodontalis LPS-stimulated osteoblasts. These results suggest that P. endodontalis LPS has the ability to promote the expression of Wnt5a in mouse osteoblasts, and this induction is mainly mediated by NF-κB pathway. TRIB3 seems to modulate the sustained expression of Wnt5a in osteoblasts stimulated by P. endodontalis LPS, as well as regulating NF-κB phosphorylation. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A study to evaluate the effect of nootropic drug-piracetam on DNA damage in leukocytes and macrophages.

PubMed

Singh, Sarika; Goswami, Poonam; Swarnkar, Supriya; Singh, Sheelendra Pratap; Wahajuddin; Nath, Chandishwar; Sharma, Sharad

2011-11-27

Piracetam is a nootropic drug that protects neurons in neuropathological and age-related diseases and the activation and modulation of peripheral blood cells in patients with neuropathological conditions is well known. Therefore, in the present study, in vivo, ex vivo, and in vitro tests were conducted to investigate the effect of piracetam on leukocytes and macrophages. Lipopolysaccharide (LPS) causes oxidative DNA damage; thus, in the present study, LPS was used as a tool to induce DNA damage. In vivo experiments were conducted on Sprague Dawley rats, and piracetam (600mg/kg, oral) was provided for five consecutive days. On the fifth day, a single injection of LPS (10mg/kg, i.p.) was administered. Three hours after LPS injection, blood leukocytes and peritoneal macrophages were collected and processed, and a variety of different assays were conducted. Ex vivo treatments were performed on isolated rat blood leukocytes, and in vitro experiments were conducted on rat macrophage cell line J774A.1. Cell viability and the level of reactive oxygen species (ROS), mitochondrial membrane potential (MMP) and DNA damage were estimated in untreated (control) and piracetam-, LPS- and LPS+piracetam-treated leukocytes and macrophages. In vivo experiments revealed that rats pretreated with piracetam were significantly protected against LPS-induced increases in ROS levels and DNA damage. Ex vivo isolated leukocytes and J774A.1 cells treated with LPS exhibited augmented ROS levels and DNA damage, which were attenuated with piracetam treatment. Thus, the present study revealed the salutary effect of piracetam against LPS-induced oxidative stress and DNA damage in leukocytes and macrophages. Copyright © 2011 Elsevier B.V. All rights reserved.

[Effect of lipopolysaccharides from Porphyromonas endodontalis on the expression of interleukin-34 in mouse osteoblasts].

PubMed

Yu, Ya-Qiong; Guo, Jia-Jie; Qiu, Li-Hong; Li, Xiao-Lin; Yang, Di; Guo, Yan

2017-02-01

To investigate the effects of lipopolysaccharides (LPS) extracted from Porphyromonas endodontalis (P.e) on the expression of interleukin-34 (IL-34) mRNA in MC3T3-E1 cells and the role of p38MAPK, ERK1/2, NF-κB and SIRT1 in the process. MC3T3-E1 cells were treated with different concentrations of P.e-LPS(0-50 mg/L) and 20 mg/L P.e-LPS for different time (0-24 h). The expression of IL-34 mRNA was detected by real-time reverse transcription-polymerase chain reaction (real time RT-PCR). MC3T3-E1 cells were pretreated with inhibitor of NF-κB(BAY 11-7082),inhibitor of p38MAPK (SB203580), inhibitor of ERK1/2 (PD98059), agonist of sirtuin1 (SIRT1) [resveratrol (RES)] and inhibitor of SIRT1 (EX-527) for 1 h, and then were treated with 20 mg/L P.e-LPS. The expression of IL-34 mRNA was detected by real time RT-PCR. Statistical analysis was performed using one-way ANOVA and Dunnett t test with SPSS 13.0 software package. The level of IL-34 mRNA increased significantly after treatment with different concentrations of P.e-LPS(0-50 mg/L)，which indicated that P.e-LPS induced osteoblasts to express IL-34 mRNA in a dose-dependent manner. Maximal induction of IL-34 mRNA expression was observed in MC3T3-E1 cells treated with 20 mg/L P.e-LPS for 24 h.At 48 h, the expression of IL-34 mRNA decreased gradually. The mRNA of IL-34 decreased significantly after pretreatment with 10 μmol/L BAY-117082, SB203580 and PD98059 for 1 h. P.e-LPS-induced IL-34 upregulation was attenuated by pretreatment with RES, but increased by EX-527. These results suggest that P.e-LPS may mediate IL-34 mRNA expression in MC3T3-E1 cells. This process is dependent, at least in part, on p38MAPK, ERK1/2, NF-κB and SIRT1 signaling pathways.

Lipopolysaccharide-induced sickness behaviour evaluated in different models of anxiety and innate fear in rats.

PubMed

Bassi, Gabriel S; Kanashiro, Alexandre; Santin, Francele M; de Souza, Glória E P; Nobre, Manoel J; Coimbra, Norberto C

2012-04-01

The fact that there is a complex and bidirectional communication between the immune and nervous systems has been well demonstrated. Lipopolysaccharide (LPS), a component of gram-negative bacteria, is widely used to systematically stimulate the immune system and generate profound physiological and behavioural changes, also known as 'sickness behaviour' (e.g. anhedonia, lethargy, loss of appetite, anxiety, sleepiness). Different ethological tools have been used to analyse the behavioural modifications induced by LPS; however, many researchers analysed only individual tests, a single LPS dose or a unique ethological parameter, thus leading to disagreements regarding the data. In the present study, we investigated the effects of different doses of LPS (10, 50, 200 and 500 μg/kg, i.p.) in young male Wistar rats (weighing 180-200 g; 8-9 weeks old) on the ethological and spatiotemporal parameters of the elevated plus maze, light-dark box, elevated T maze, open-field tests and emission of ultrasound vocalizations. There was a dose-dependent increase in anxiety-like behaviours caused by LPS, forming an inverted U curve peaked at LPS 200 μg/kg dose. However, these anxiety-like behaviours were detected only by complementary ethological analysis (stretching, grooming, immobility responses and alarm calls), and these reactions seem to be a very sensitive tool in assessing the first signs of sickness behaviour. In summary, the present work clearly showed that there are resting and alertness reactions induced by opposite neuroimmune mechanisms (neuroimmune bias) that could lead to anxiety behaviours, suggesting that misunderstanding data could occur when only few ethological variables or single doses of LPS are analysed. Finally, it is hypothesized that this bias is an evolutionary tool that increases animals' security while the body recovers from a systemic infection. © 2011 The Authors. Basic & Clinical Pharmacology & Toxicology © 2011 Nordic Pharmacological Society.

EPCK1, a vitamin C and E analogue, reduces endotoxin-induced systemic inflammation in mice.

PubMed

Shingu, Chihiro; Hagiwara, Satoshi; Iwasaka, Hideo; Matsumoto, Shigekiyo; Koga, Hironori; Yokoi, Isao; Noguchi, Takayuki

2011-12-01

Phosphate ester of vitamin C and vitamin E (EPCK1), a strong antioxidant, is a water- and lipid-soluble phosphate ester of vitamin C and vitamin E. In the current study, we tested whether EPCK1 inhibits oxidative stress and prevents systemic inflammation. Mice were randomly divided into a negative control group, a lipopolysaccharide (LPS)-induced sepsis group, and a group treated with an intraperitoneal infusion of EPCK1 (10 mg/kg) prior to or following LPS administration. In addition, RAW 264.7 cells were treated with LPS in the presence or absence of EPCK1. We examined levels of high mobility group box 1 (HMGB1) protein and inducible nitric oxide synthase (iNOS) in both in vivo and in vitro experiments, and liver histopathology in the in vivo experiment. Liver histopathology significantly improved in the EPCK1 group compared with the LPS group. Although LPS administration increased HMGB1 and nitric oxide (NO) secretion, EPCK1 decreased the secretion of these mediators in vitro and in vivo. Our findings suggest that EPCK1 may inhibit inflammation and potentially function as a novel anti-inflammatory therapeutic agent. Copyright © 2011 Elsevier Inc. All rights reserved.

Inhibition of Neddylation Represses Lipopolysaccharide-induced Proinflammatory Cytokine Production in Macrophage Cells

PubMed Central

Chang, Fang-Mei; Reyna, Sara M.; Granados, Jose C.; Wei, Sung-Jen; Innis-Whitehouse, Wendy; Maffi, Shivani K.; Rodriguez, Edward; Slaga, Thomas J.; Short, John D.

2012-01-01

Cullin-RING E3 ligases (CRLs) are a class of ubiquitin ligases that control the proteasomal degradation of numerous target proteins, including IκB, and the activity of these CRLs are positively regulated by conjugation of a Nedd8 polypeptide onto Cullin proteins in a process called neddylation. CRL-mediated degradation of IκB, which normally interacts with and retains NF-κB in the cytoplasm, permits nuclear translocation and transactivation of the NF-κB transcription factor. Neddylation occurs through a multistep enzymatic process involving Nedd8 activating enzymes, and recent studies have shown that the pharmacological agent, MLN4924, can potently inhibit Nedd8 activating enzymes, thereby preventing neddylation of Cullin proteins and preventing the degradation of CRL target proteins. In macrophages, regulation of NF-κB signaling functions as a primary pathway by which infectious agents such as lipopolysaccharides (LPSs) cause the up-regulation of proinflammatory cytokines. Here we have analyzed the effects of MLN4924, and compared the effects of MLN4924 with a known anti-inflammatory agent (dexamethasone), on certain proinflammatory cytokines (TNF-α and IL-6) and the NF-κB signaling pathway in LPS-stimulated macrophages. We also used siRNA to block neddylation to assess the role of this molecular process during LPS-induced cytokine responsiveness. Our results demonstrate that blocking neddylation, either pharmacologically or using siRNA, abrogates the increase in certain proinflammatory cytokines secreted from macrophages in response to LPS. In addition, we have shown that MLN4924 and dexamethasone inhibit LPS-induced cytokine up-regulation at the transcriptional level, albeit through different molecular mechanisms. Thus, neddylation represents a novel molecular process in macrophages that can be targeted to prevent and/or treat the LPS-induced up-regulation of proinflammatory cytokines and the disease processes associated with their up-regulation. PMID:22927439

The Quality Control Algorithms Used in the Process of Creating the NASA Kennedy Space Center Lightning Protection System Towers Meteorological Database

NASA Technical Reports Server (NTRS)

Orcutt, John M.; Brenton, James C.

2016-01-01

The methodology and the results of the quality control (QC) process of the meteorological data from the Lightning Protection System (LPS) towers located at Kennedy Space Center (KSC) launch complex 39B (LC-39B) are documented in this paper. Meteorological data are used to design a launch vehicle, determine operational constraints, and to apply defined constraints on day-of-launch (DOL). In order to properly accomplish these tasks, a representative climatological database of meteorological records is needed because the database needs to represent the climate the vehicle will encounter. Numerous meteorological measurement towers exist at KSC; however, the engineering tasks need measurements at specific heights, some of which can only be provided by a few towers. Other than the LPS towers, Tower 313 is the only tower that provides observations up to 150 m. This tower is located approximately 3.5 km from LC-39B. In addition, data need to be QC'ed to remove erroneous reports that could pollute the results of an engineering analysis, mislead the development of operational constraints, or provide a false image of the atmosphere at the tower's location.

Effects of antidepressants on alternations in serum cytokines and depressive-like behavior in mice after lipopolysaccharide administration.

PubMed

Ohgi, Yuta; Futamura, Takashi; Kikuchi, Tetsuro; Hashimoto, Kenji

2013-02-01

Accumulating evidence suggests that inflammation may play a role in the pathophysiology of major depressive disorder (MDD). Antidepressants, including selective serotonin reuptake inhibitors (SSRIs) and serotonin and norepinephrine reuptake inhibitors (SNRIs), possess anti-inflammatory effects in vitro. Here, we examined the effects of SSRIs and SNRIs on lipopolysaccharide (LPS)-induced inflammation and depressive-like behavior in male mice. A single administration of LPS (0.5mg/kg, i.p.) increased serum levels of the pro-inflammatory cytokine, tumor necrosis factor-α (TNFα) and the anti-inflammatory cytokine, interleukin-10 (IL-10) in mice. Pretreatment with SSRIs (fluoxetine and paroxetine), SNRIs (venlafaxine and duloxetine), or 5-hydroxytryptophan (5-HTP), a precursor of serotonin, attenuated LPS-induced increases in TNFα, whereas it increased serum levels of IL-10, in mice treated with LPS. In the tail suspension test (TST), LPS increased the immobility time without affecting spontaneous locomotor activity, suggesting that LPS induced depressive-like behavior in mice. Treatment with fluoxetine (30 mg/kg) or paroxetine (10mg/kg) significantly shortened LPS-induced increases of immobility time. These results suggested that antidepressants exert anti-inflammatory effects in vivo, and that the serotonergic system may partially mediate these effects. In addition, the anti-inflammatory effects of antidepressants may help alleviate the symptoms of LPS-induced depression in mice. Copyright © 2012 Elsevier Inc. All rights reserved.

Adiponectin attenuates LPS-induced acute lung injury through suppression of endothelial cell activation1

PubMed Central

Konter, Jason M; Parker, Jennifer L; Baez, Elizabeth; Li, Stephanie Z; Ranscht, Barbara; Denzel, Martin; Little, Frederic F; Nakamura, Kazuto; Ouchi, Noriyuki; Fine, Alan; Walsh, Kenneth; Summer, Ross S

2011-01-01

Adiponectin (APN) is an adipose tissue-derived factor with anti-inflammatory and vascular protective properties whose levels paradoxically decrease with increasing body fat. In this study, APN’s role in the early development of ALI to lipopolysaccharide (LPS) was investigated. Intra-tracheal (i.t.) LPS elicited an exaggerated systemic inflammatory response in APN-deficient (APN−/−) mice compared to wild-type (wt) littermates. Increased lung injury and inflammation were observed in APN−/− mice as early as 4 hours after delivery of LPS. Targeted gene expression profiling performed on immune and endothelial cells isolated from lung digests 4 hours after LPS administration showed increased pro-inflammatory gene expression (e.g. IL-6) only in endothelial cells of APN−/− mice when compared to wt mice. Direct effects on lung endothelium were demonstrated by APN’s ability to inhibit LPS-induced IL-6 production in primary human endothelial cells in culture. Furthermore, T-cadherin-deficient (T-cad−/−) mice that have significantly reduced lung airspace APN but high serum APN levels had pulmonary inflammatory responses after i.t. LPS that were similar to those of wt mice. These findings indicate the importance of serum APN in modulating LPS-induced ALI and suggest that conditions leading to hypoadiponectinemia (e.g. obesity) predispose to development of ALI through exaggerated inflammatory response in pulmonary vascular endothelium. PMID:22156343

Hypoxia preconditioning increases survival and decreases expression of Toll-like receptor 4 in pulmonary artery endothelial cells exposed to lipopolysaccharide.

PubMed

Ali, Irshad; Nanchal, Rahul; Husnain, Fouad; Audi, Said; Konduri, G Ganesh; Densmore, John C; Medhora, Meetha; Jacobs, Elizabeth R

2013-09-01

Abstract Pulmonary or systemic infections and hypoxemic respiratory failure are among the leading causes of admission to intensive care units, and these conditions frequently exist in sequence or in tandem. Inflammatory responses to infections are reproduced by lipopolysaccharide (LPS) engaging Toll-like receptor 4 (TLR4). Apoptosis is a hallmark of lung injury in sepsis. This study was conducted to determine whether preexposure to LPS or hypoxia modulated the survival of pulmonary artery endothelial cells (PAECs). We also investigated the role TLR4 receptor expression plays in apoptosis due to these conditions. Bovine PAECs were cultured in hypoxic or normoxic environments and treated with LPS. TLR4 antagonist TAK-242 was used to probe the role played by TLR4 receptors in cell survival. Cell apoptosis and survival were measured by caspase 3 activity and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) incorporation. TLR4 expression and tumor necrosis factor α (TNF-α) production were also determined. LPS increased caspase 3 activity in a TAK-242-sensitive manner and decreased MTT incorporation. Apoptosis was decreased in PAECs preconditioned with hypoxia prior to LPS exposure. LPS increased TNF-α production, and hypoxic preconditioning blunted it. Hypoxic preconditioning reduced LPS-induced TLR4 messenger RNA and TLR4 protein. TAK-242 decreased to baseline the LPS-stimulated expression of TLR4 messenger RNA regardless of environmental conditions. In contrast, LPS followed by hypoxia substantially increased apoptosis and cell death. In conclusion, protection from LPS-stimulated PAEC apoptosis by hypoxic preconditioning is attributable in part to reduction in TLR4 expression. If these signaling pathways apply to septic patients, they may account for differing sensitivities of individuals to acute lung injury depending on oxygen tensions in PAECs in vivo.

Neutrophil-cytokine interactions in a rat model of sulindac-induced idiosyncratic liver injury.

PubMed

Zou, Wei; Roth, Robert A; Younis, Husam S; Malle, Ernst; Ganey, Patricia E

2011-12-18

Previous studies indicated that lipopolysaccharide (LPS) interacts with the nonsteroidal anti-inflammatory drug sulindac (SLD) to produce liver injury in rats. In the present study, the mechanism of SLD/LPS-induced liver injury was further investigated. Accumulation of polymorphonuclear neutrophils (PMNs) in the liver was greater in SLD/LPS-cotreated rats compared to those treated with SLD or LPS alone. In addition, PMN activation occurred specifically in livers of rats cotreated with SLD/LPS. The hypothesis that PMNs and proteases released from them play critical roles in the hepatotoxicity was tested. SLD/LPS-induced liver injury was attenuated by prior depletion of PMNs or by treatment with the PMN protease inhibitor, eglin C. Previous studies suggested that tumor necrosis factor-α (TNF) and the hemostatic system play critical roles in the pathogenesis of liver injury induced by SLD/LPS. TNF and plasminogen activator inhibitor-1 (PAI-1) can contribute to hepatotoxicity by affecting PMN activation and fibrin deposition. Therefore, the role of TNF and PAI-1 in PMN activation and fibrin deposition in the SLD/LPS-induced liver injury model was tested. Neutralization of TNF or inhibition of PAI-1 attenuated PMN activation. TNF had no effect on PAI-1 production or fibrin deposition. In contrast, PAI-1 contributed to fibrin deposition in livers of rats treated with SLD/LPS. In summary, PMNs, TNF and PAI-1 contribute to the liver injury induced by SLD/LPS cotreatment. TNF and PAI-1 independently contributed to PMN activation, which is critical to the pathogenesis of liver injury. Moreover, PAI-1 contributed to liver injury by promoting fibrin deposition. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Dual effect of LPS on murine myeloid leukemia cells: Pro-proliferation and anti-proliferation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Lingling; Noncoding RNA Center, Yangzhou University, Yangzhou 225001; Zhao, Yingmin

Modification of the bone marrow microenvironment is considered as a promising strategy to control leukemic cell proliferation, diseases progression and relapse after treatment. However, due to the diversity and complexity of the cellular and molecular compartments in the leukemic microenvironment, it is extremely difficult to dissect the role of each individual molecule or cell type in vivo. Here we established an in vitro system to dissect the role of lipopolysaccharide (LPS), stromal cells and endothelial cells in the growth of mouse myeloid tumor cells and B-lymphoma cells. We found that either LPS or bone marrow stromal cells as a feedermore » layer in culture is required for the proliferation of myeloid tumor cells. Surprisingly, the growth of myeloid leukemic cells on stromal cells is strongly inhibited when coupled with LPS in culture. This opposing effect of LPS, a complete switch from pro-proliferation to antitumor growth is due, at least in part, to the rapidly increased production of interleukin 12, Fas ligand and tissue inhibitor of metalloproteinases-2 from stromal cells stimulated by LPS. These results demonstrate that LPS can either facilitate or attenuate tumor cell proliferation, thus changing the disease course of myeloid leukemias through its direct effect or modulation of the tumor microenvironment. - Highlights: • LPS alone in culture is required for the proliferation of murine myeloid tumor cells. • Bone marrow stromal cells as a feeder layer is also required for the proliferation of myeloid tumor cells. • However, the growth of myeloid tumor cells is inhibited when LPS and stromal cells are both available in culture. • Thus LPS can either facilitate or attenuate tumor growth through its direct effect or modulation of tumor microenvironment.« less

Presumable role of outer membrane proteins of Salmonella containing sialylated lipopolysaccharides serovar Ngozi, sv. Isaszeg and subspecies arizonae in determining susceptibility to human serum.

PubMed

Futoma-Kołoch, Bożena; Godlewska, Urszula; Guz-Regner, Katarzyna; Dorotkiewicz-Jach, Agata; Klausa, Elżbieta; Rybka, Jacek; Bugla-Płoskońska, Gabriela

2015-01-01

The O48 group comprises Salmonella bacteria containing sialic acid in the lipopolysaccharide (LPS). Bacteria with sialylated surface structures are described as pathogens that avoid immunological response of the host by making similar their surface antigens to the host's tissues (molecular mimicry). It is known that the smooth-type LPS of Salmonella enterica and outer membrane proteins (OMP) PgtE, PagC and Rck mediate serum resistant phenotype by affecting complement system (C). The aim of this study was to investigate C3 component activation by Salmonella O48 LPS and OMP. In the present study, we examined C3 component deposition on the three Salmonella O48 strains: S. enterica subspecies enterica serovar Ngozi, S. enterica subsp. enterica sv. Isaszeg, and S. enterica subsp. arizonae containing sialic acid in the O-specific part of LPS. The greatest C3 deposition occurred on Salmonella sv. Isaszeg cells (p < 0.005) as well as on their LPS (low content of sialic acid in LPS) (p < 0.05) after 45 min of incubation in 50% human serum. Weaker C3 deposition ratio on the Salmonella sv. Ngozi (high content of sialic acid in LPS) and Salmonella subsp. arizonae (high content of sialic acid in LPS) cells correlated with the lower C3 activation on their LPS. Immunoblotting revealed that OMP isolated from the tested strains also bound C3 protein fragments. We suggest that activation of C3 serum protein is dependent on the sialic acid contents in the LPS as well as on the presence of OMP in the range of molecular masses of 35-48 kDa.

Systemic inflammation in early neonatal mice induces transient and lasting neurodegenerative effects.

PubMed

Cardoso, Filipa L; Herz, Jasmin; Fernandes, Adelaide; Rocha, João; Sepodes, Bruno; Brito, Maria A; McGavern, Dorian B; Brites, Dora

2015-04-29

The inflammatory mediator lipopolysaccharide (LPS) has been shown to induce acute gliosis in neonatal mice. However, the progressive effects on the murine neurodevelopmental program over the week that follows systemic inflammation are not known. Thus, we investigated the effects of repeated LPS administration in the first postnatal week in mice, a condition mimicking sepsis in late preterm infants, on the developing central nervous system (CNS). Systemic inflammation was induced by daily intraperitoneal administration (i.p.) of LPS (6 mg/kg) in newborn mice from postnatal day (PND) 4 to PND6. The effects on neurodevelopment were examined by staining the white matter and neurons with Luxol Fast Blue and Cresyl Violet, respectively. The inflammatory response was assessed by quantifying the expression/activity of matrix metalloproteinases (MMP), toll-like receptor (TLR)-4, high mobility group box (HMGB)-1, and autotaxin (ATX). In addition, B6 CX3CR1(gfp/+) mice combined with cryo-immunofluorescence were used to determine the acute, delayed, and lasting effects on myelination, microglia, and astrocytes. LPS administration led to acute body and brain weight loss as well as overt structural changes in the brain such as cerebellar hypoplasia, neuronal loss/shrinkage, and delayed myelination. The impaired myelination was associated with alterations in the proliferation and differentiation of NG2 progenitor cells early after LPS administration, rather than with excessive phagocytosis by CNS myeloid cells. In addition to disruptions in brain architecture, a robust inflammatory response to LPS was observed. Quantification of inflammatory biomarkers revealed decreased expression of ATX with concurrent increases in HMGB1, TLR-4, and MMP-9 expression levels. Acute astrogliosis (GFAP(+) cells) in the brain parenchyma and at the microvasculature interface together with parenchymal microgliosis (CX3CR1(+) cells) were also observed. These changes preceded the migration/proliferation of CX3CR1(+) cells around the vessels at later time points and the subsequent loss of GFAP(+) astrocytes. Collectively, our study has uncovered a complex innate inflammatory reaction and associated structural changes in the brains of neonatal mice challenged peripherally with LPS. These findings may explain some of the neurobehavioral abnormalities that develop following neonatal sepsis.

JNK1 Mediates Lipopolysaccharide-Induced CD14 and SR-AI Expression and Macrophage Foam Cell Formation.

PubMed

An, Dong; Hao, Feng; Hu, Chen; Kong, Wei; Xu, Xuemin; Cui, Mei-Zhen

2017-01-01

Foam cell formation is the key process in the development of atherosclerosis. The uptake of oxidized low-density lipoprotein (oxLDL) converts macrophages into foam cells. We recently reported that lipopolysaccharide (LPS)-induced foam cell formation is regulated by CD14 and scavenger receptor AI (SR-AI). In this study, we employed pharmaceutical and gene knockdown approaches to determine the upstream molecular mediators, which control LPS-induced foam cell formation. Our results demonstrated that the specific c-Jun N-terminal kinase (JNK) pathway inhibitor, SP600125, but neither the specific inhibitor of extracellular signaling-regulated kinase (ERK) kinase MEK1/2, U0126, nor the specific inhibitor of p38 MAPK, SB203580, significantly blocks LPS-induced oxLDL uptake, suggesting that the JNK pathway is the upstream mediator of LPS-induced oxLDL uptake/foam cell formation. To address whether JNK pathway mediates LPS-induced oxLDL uptake is due to JNK pathway-regulated CD14 and SR-AI expression, we assessed whether the pharmaceutical inhibitor of JNK influences LPS-induced expression of CD14 and SR-AI. Our results indicate that JNK pathway mediates LPS-induced CD14 and SR-AI expression. To conclusively address the isoform role of JNK family, we depleted JNK isoforms using the JNK isoform-specific siRNA. Our data showed that the depletion of JNK1, but not JNK2 blocked LPS-induced CD14/SR-AI expression and foam cell formation. Taken together, our results reveal for the first time that JNK1 is the key mediator of LPS-induced CD14 and SR-AI expression in macrophages, leading to LPS-induced oxLDL uptake/foam cell formation. We conclude that the novel JNK1/CD14/SR-AI pathway controls macrophage oxLDL uptake/foam cell formation.

Neutrophil interaction with the hemostatic system contributes to liver injury in rats cotreated with lipopolysaccharide and ranitidine.

PubMed

Deng, Xiaomin; Luyendyk, James P; Zou, Wei; Lu, Jingtao; Malle, Ernst; Ganey, Patricia E; Roth, Robert A

2007-08-01

Cotreatment of rats with nontoxic doses of ranitidine (RAN) and lipopolysaccharide (LPS) causes liver injury, and this drug-inflammation interaction might be a model for idiosyncratic adverse drug responses in humans. Both polymorphonuclear neutrophils (PMNs) and the hemostatic system have been shown to be important in the injury. We tested the hypothesis that PMNs cause liver injury by interacting with the hemostatic system and producing subsequent hypoxia. In rats cotreated with LPS/RAN, PMN depletion by anti-PMN serum reduced fibrin deposition and hypoxia in the liver. PMN depletion also reduced the plasma concentration of active plasminogen activator inhibitor-1 (PAI-1), a major down-regulator of the fibrinolytic system. This suggests that PMNs promote fibrin deposition by increasing PAI-1 concentration. PMNs were activated in the livers of LPS/RAN-cotreated rats as evidenced by increased staining for hypochlorous acid-modified proteins generated by the myeloperoxidase-hydrogen peroxide-chloride system of activated phagocytes. Antiserum against the PMN adhesion molecule CD18 protected against LPS/RAN-induced liver injury. Because CD18 is important for PMN transmigration and activation, these results suggest that PMN activation is required for the liver injury. Furthermore, anti-CD18 serum reduced biomarkers of hemostasis and hypoxia, suggesting the necessity for PMN activation in the interaction between PMNs and the hemostatic system/hypoxia. Liver injury, liver fibrin, and plasma PAI-1 concentration were also reduced by eglin C, an inhibitor of proteases released by activated PMNs. In summary, PMNs are activated in LPS/RAN-cotreated rats and participate in the liver injury in part by contributing to hemostasis and hypoxia.

The effect of antibiotics on social aversion following early life inflammation.

PubMed

Kentner, Amanda C; Khan, Urma; MacRae, M; Dowd, Scot E; Yan, Siyang

2018-06-13

Epidemiological evidence suggests that exposure to infection during early development increases the risk for neurodevelopmental disorders associated with symptoms such as a decreased desire to engage in social interactions. In animals, disruptions in social behavior can be modelled by administering bacterial mimetics such as liposaccharide (LPS). However, when evaluating social interactions in the laboratory, attention is rarely directed on the reciprocal relationship as a whole, which is important as peers may drive social withdrawal. Previously, we have shown that male adolescent rats treated neonatally (n) with LPS receive less contact from their conspecifics in a social interaction test, and that this effect is mediated through olfactory communication. In the present study, we reconfirmed this effect using a more direct social test and evaluated the hypothesis that changes in the microbiome underlie the olfactory induced social aversion. Male and female Sprague-Dawley rats were administered nLPS (50 μg/kg, i.p) or nSaline on postnatal days (P)3 and 5. On P40, adolescent nLPS treated males received less contact in a social preference test compared to nSaline treated controls, an effect not observed in females. To confirm that nLPS led male rats to elicit a scent cue, resulting in social aversion, a subset of neurotypical conspecifics underwent an anosmia procedure that disrupted their olfactory processing via olfactory neuroepithelium degeneration. This normalized the contact that they directed towards nLPS and nSaline male rats. Although 16 s rRNA sequencing failed to detect significant differences in bacterial phyla across either sex or neonatal treatment, treating male nLPS rats with an antibiotic cocktail, which induced clear changes in microbial communities, diminished the social rejection effect. Therefore, manipulation of the microbiome appears to affect social communication where there exists an underlying deficit. Moreover, our data reaffirm that social engagement is a reciprocal process and the behavior of all individuals within a dynamic interaction should be evaluated. Copyright © 2018 Elsevier Inc. All rights reserved.

1,25-Dihydroxyvitamin D(3) Inhibits Podocyte uPAR Expression and Reduces Proteinuria

PubMed Central

Liu, Shuangxin; Xie, Shaoting; Yang, Yun; Ma, Juan; Deng, Yujun; Wang, Wenjian; Xu, Lixia; Li, Ruizhao; Zhang, Li; Yu, Chunping; Shi, Wei

2013-01-01

Background Accumulating studies have demonstrated that 1,25-Dihydroxyvitamin D(3) (1,25(OH)2D3) reduces proteinuria and protects podocytes from injury. Recently, urokinase receptor (uPAR) and its soluble form have been shown to cause podocyte injury and focal segmental glomerulosclerosis (FSGS). Here, our findings showed that 1,25(OH)2D3 did inhibit podocyte uPAR expression and attenuate proteinuria and podocyte injury. Methodology/Principal Findings In this study, the antiproteinuric effect of 1,25(OH)2D3 was examined in the lipopolysaccharide mice model of transient proteinuria (LPS mice) and in the 5/6 nephrectomy rat FSGS model(NTX rats). uPAR protein expression were tested by flow cytometry, immune cytochemistry and western blot analysis, and uPAR mRNA expression by real-time quantitative PCR in cultured podocytes and kidney glomeruli isolated from mice and rats. Podocyte motility was observed by transwell migration assay and wound healing assay. Podocyte foot processes effacement was identified by transmission electron microscopy. We found that 1,25(OH)2D3 inhibited podocyte uPAR mRNA and protein synthesis in LPS-treated podocytes, LPS mice and NTX rats, along with 1,25(OH)2D3 reducing proteinuria in NTX rats and LPS mice.1,25(OH)2D3 reduced glomerulosclerosis in NTX rats and alleviated podocyte foot processes effacement in LPS mice. Transwell migration assay and wound healing assay showed that LPS-induced podocyte motility, irrespective of random or directed motility, were substantially reduced by 1,25(OH)2D3. Conclusions/Significance Our results demonstrated that 1,25(OH)2D3 inhibited podocyte uPAR expression in vitro and in vivo, which may be an unanticipated off target effect of 1,25(OH)2D3 and explain its antiproteinuric effect in the 5/6 nephrectomy rat FSGS model and the LPS mouse model of transient proteinuria. PMID:23741418

Progesterone Is Essential for Protecting against LPS-Induced Pregnancy Loss. LIF as a Potential Mediator of the Anti-inflammatory Effect of Progesterone

PubMed Central

Aisemberg, Julieta; Vercelli, Claudia A.; Bariani, María V.; Billi, Silvia C.; Wolfson, Manuel L.; Franchi, Ana M.

2013-01-01

Lipopolysaccharide (LPS) administration to mice on day 7 of gestation led to 100% embryonic resorption after 24 h. In this model, nitric oxide is fundamental for the resorption process. Progesterone may be responsible, at least in part, for a Th2 switch in the feto-maternal interface, inducing active immune tolerance against fetal antigens. Th2 cells promote the development of T cells, producing leukemia inhibitory factor (LIF), which seems to be important due to its immunomodulatory action during early pregnancy. Our aim was to evaluate the involvement of progesterone in the mechanism of LPS-induced embryonic resorption, and whether LIF can mediate hormonal action. Using in vivo and in vitro models, we provide evidence that circulating progesterone is an important component of the process by which infection causes embryonic resorption in mice. Also, LIF seems to be a mediator of the progesterone effect under inflammatory conditions. We found that serum progesterone fell to very low levels after 24 h of LPS exposure. Moreover, progesterone supplementation prevented embryonic resorption and LPS-induced increase of uterine nitric oxide levels in vivo. Results show that LPS diminished the expression of the nuclear progesterone receptor in the uterus after 6 and 12 h of treatment. We investigated the expression of LIF in uterine tissue from pregnant mice and found that progesterone up-regulates LIF mRNA expression in vitro. We observed that LIF was able to modulate the levels of nitric oxide induced by LPS in vitro, suggesting that it could be a potential mediator of the inflammatory action of progesterone. Our observations support the view that progesterone plays a critical role in a successful pregnancy as an anti-inflammatory agent, and that it could have possible therapeutic applications in the prevention of early reproductive failure associated with inflammatory disorders. PMID:23409146

Identification of copper/zinc superoxide dismutase as a novel nitric oxide-regulated gene in rat glomerular mesangial cells and kidneys of endotoxemic rats.

PubMed

Frank, S; Zacharowski, K; Wray, G M; Thiemermann, C; Pfeilschifter, J

1999-05-01

To define the mechanism of nitric oxide (NO) action in the glomerulus, we attempted to identify genes that are regulated by NO in rat glomerular mesangial cells. We identified a Cu/Zn superoxide dismutase (SOD) that was strongly induced in these cells by treatment with S-nitroso-glutathione as a NO-donating agent. Bacterial lipopolysaccharide (LPS) acutely decreased Cu/Zn SOD mRNA levels. The LPS-mediated decrease in Cu/Zn SOD is reversed by endogenously produced NO, as LPS also induced a delayed strong iNOS expression in these cells in vitro, which is accompanied by increased Cu/Zn SOD expression. NO dependency of Cu/Zn SOD mRNA recovery could be demonstrated by inhibition of this process by L-NG-monomethylarginine, an inhibitor of NOS enzymatic activity. To demonstrate the in vivo relevance of our observations, we have chosen LPS-treated rats as a model for induction of a systemic inflammatory response. In these animals, we demonstrate a direct coupling of Cu/Zn SOD expression levels to the presence of NO, as Cu/Zn SOD mRNA levels declined during acute inflammation in the presence of a selective inhibitor of iNOS. We propose that the up-regulation of Cu/Zn SOD by endogenous NO may serve as an adaptive, protective mechanism to prevent the formation of toxic quantities of peroxynitrite in conditions associated with iNOS induction during endotoxic shock.

Functional Toll-like receptor 4 expressed in lactotrophs mediates LPS-induced proliferation in experimental pituitary hyperplasia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sabatino, María Eugenia; Sosa, Liliana del Valle; Petiti, Juan Pablo

Toll like receptor 4 (TLR4) has been characterized for its ability to recognize bacterial endotoxin lipopolysaccharide (LPS). Considering that infections or inflammatory processes might contribute to the progression of pituitary tumors, we analyzed the TLR4 functional role by evaluating the LPS effect on lactotroph proliferation in primary cultures from experimental pituitary tumors, and examined the involvement of PI3K-Akt and NF-κB activation in this effect. In addition, the role of 17β-estradiol as a possible modulator of LPS-induced PRL cell proliferation was further investigated. In estrogen-induced hyperplasic pituitaries, LPS triggered lactotroph cell proliferation. However, endotoxin failed to increase the number of lactotrophsmore » taking up BrdU in normal pituitaries. Moreover, incubation with anti-TLR4 antibody significantly reduced LPS-induced lactotroph proliferation, suggesting a functional role of this receptor. As a sign of TLR4 activation, an LPS challenge increased IL-6 release in normal and tumoral cells. By flow cytometry, TLR4 baseline expression was revealed at the plasma membrane of tumoral lactotrophs, without changes noted in the percentage of double PRL/TLR4 positive cells after LPS stimulus. Increases in TLR4 intracellular expression were detected as well as rises in CD14, p-Akt and NF-κB after an LPS challenge, as assessed by western blotting. The TLR4/PRL and PRL/NF-κB co-localization was also corroborated by immunofluorescence and the involvement of PI3K/Akt signaling in lactotroph proliferation and IL-6 release was revealed through the PI3K inhibitor Ly-294002. In addition, 17β-estradiol attenuated the LPS-evoked increase in tumoral lactotroph proliferation and IL-6 release. Collectively these results demonstrate the presence of functional TLR4 in lactotrophs from estrogen-induced hyperplasic pituitaries, which responded to the proliferative stimulation and IL-6 release induced by LPS through TLR4/CD14, with a contribution of the PI3K-Akt and NF-κB signaling pathways. - Highlights: • In hyperplastic pituitaries, LPS triggered the lactotroph cell proliferation and IL-6 release. • Functional Toll-like receptor 4 (TLR4) is expressed at the plasma membrane of tumoral lactotrophs. • Increases in TLR4 and CD14 intracellular expression levels were detected after an LPS challenge. • The proliferative stimulation and IL-6 release involved the PI3K-Akt pathway and NF-κB activation. • 17β-estradiol attenuated the LPS-evoked tumoral lactotroph proliferation and IL-6 secretion.« less

Daphnetin reduces endotoxin lethality in mice and decreases LPS-induced inflammation in Raw264.7 cells via suppressing JAK/STATs activation and ROS production.

PubMed

Shen, Lei; Zhou, Ting; Wang, Jing; Sang, Xiumei; Lan, Lei; Luo, Lan; Yin, Zhimin

2017-07-01

Here, we used various approaches to investigate the suppressive role of daphnetin in LPS-induced inflammatory response, with the goal to understand the underlining molecular mechanism by which daphnetin regulated these processes. We examined the survival rate and the lung injury in the mice model of LPS-induced endotoxemia. The production of pro-inflammatory factors including tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), IL-6, nitric oxide (NO), and prostaglandin E2 (PGE2) was measured by ELISA and nitrite analysis, respectively. The expression of inducible NO synthase (iNOS), cyclooxygenase 2 (COX-2), and the activation of signaling molecules was determined by immunoblotting. The production of reactive oxygen species (ROS) was measured by the ROS assay. In vivo study showed that daphnetin enhanced the survival rate and reduced the lung injury in mice with LPS-induced endotoxemia. Both in vivo and in vitro study showed that daphnetin prevented the production of pro-inflammatory factors including TNF-α, IL-1β, IL-6, NO, and PGE2 after LPS challenge. In Raw264.7 cells, we found that daphnetin reduced LPS-induced expression of iNOS and COX-2, and suppressed LPS-induced ROS production. In addition, we found that daphnetin suppressed the activation of JAK/STATs pathway and inhibited the nucleus import of STAT1 and STAT3. Here, our results indicate that daphnetin shows anti-inflammatory properties, at least in part, through suppressing LPS-induced activation of JAK/STATs cascades and ROS production.

LPS-induced inflammatory response triggers cell cycle reactivation in murine neuronal cells through retinoblastoma proteins induction.

PubMed

D'Angelo, Barbara; Astarita, Carlo; Boffo, Silvia; Massaro-Giordano, Mina; Antonella Ianuzzi, Carmelina; Caporaso, Antonella; Macaluso, Marcella; Giordano, Antonio

2017-01-01

Cell cycle reactivation in adult neurons is an early hallmark of neurodegeneration. The lipopolysaccharide (LPS) is a well-known pro-inflammatory factor that provokes neuronal cell death via glial cells activation. The retinoblastoma (RB) family includes RB1/p105, retinoblastoma-like 1 (RBL1/p107), and retinoblastoma-like 2 (Rb2/p130). Several studies have indicated that RB proteins exhibit tumor suppressor activities, and play a central role in cell cycle regulation. In this study, we assessed LPS-mediated inflammatory effect on cell cycle reactivation and apoptosis of neuronally differentiated cells. Also, we investigated whether the LPS-mediated inflammatory response can influence the function and expression of RB proteins. Our results showed that LPS challenges triggered cell cycle reactivation of differentiated neuronal cells, indicated by an accumulation of cells in S and G2/M phase. Furthermore, we found that LPS treatment also induced apoptotic death of neurons. Interestingly, we observed that LPS-mediated inflammatory effect on cell cycle re-entry and apoptosis was concomitant with the aberrant expression of RBL1/p107 and RB1/p105. To the best of our knowledge, our study is the first to indicate a role of LPS in inducing cell cycle re-entry and/or apoptosis of differentiated neuronal cells, perhaps through mechanisms altering the expression of specific members of RB family proteins. This study provides novel information on the biology of post-mitotic neurons and could help in identifying novel therapeutic targets to prevent de novo cell cycle reactivation and/or apoptosis of neurons undergoing neurodegenerative processes.

Inhibition of EphA2/EphrinA1 signal attenuates lipopolysaccharide-induced lung injury.

PubMed

Hong, Ji Young; Shin, Mi Hwa; Douglas, Ivor S; Chung, Kyung Soo; Kim, Eun Young; Jung, Ji Ye; Kang, Young Ae; Kim, Se Kyu; Chang, Joon; Kim, Young Sam; Park, Moo Suk

2016-11-01

Eph-Ephrin signalling mediates various cellular processes, including vasculogenesis, angiogenesis, cell migration, axon guidance, fluid homoeostasis and repair after injury. Although previous studies have demonstrated that stimulation of the EphA receptor induces increased vascular permeability and inflammatory response in lung injury, the detailed mechanisms of EphA2 signalling are unknown. In the present study, we evaluated the role of EphA2 signalling in mice with lipopolysaccharide (LPS)-induced lung injury. Acute LPS exposure significantly up-regulated EphA2 and EphrinA1 expression. Compared with LPS+IgG mice (IgG instillation after LPS exposure), LPS+EphA2 mAb mice [EphA2 monoclonal antibody (mAb) instillation posttreatment after LPS exposure] had attenuated lung injury and reduced cell counts and protein concentration of bronchoalveolar lavage fluid (BALF). EphA2 mAb posttreatment down-regulated the expression of phosphoinositide 3-kinases (PI3K) 110γ, phospho-Akt, phospho-NF-κB p65, phospho-Src and phospho-S6K in lung lysates. In addition, inhibiting the EphA2 receptor augmented the expression of E-cadherin, which is involved in cell-cell adhesion. Our study identified EphA2 receptor as an unrecognized modulator of several signalling pathways-including PI3K-Akt-NF-kB, Src-NF-κB, E-cadherin and mTOR-in LPS-induced lung injury. These results suggest that EphA2 receptor inhibitors may function as novel therapeutic agents for LPS-induced lung injury. © 2016 The Author(s). published by Portland Press Limited on behalf of the Biochemical Society.

Influence of corrosion on lipopolysaccharide affinity for two different titanium materials.

PubMed

Barão, Valentim Adelino Ricardo; Mathew, Mathew T; Yuan, Judy Chia-Chun; Knoernschild, Kent L; Assunção, Wirley Gonçalves; Wimmer, Markus A; Sukotjo, Cortino

2013-12-01

Titanium is subject to corrosion in the oral cavity, which could contribute to periimplantitis. However, the effect of corrosion on the lipopolysaccharide affinity for titanium remains unknown. This study evaluated the role of corrosion (in artificial saliva at pHs 3, 6.5, and 9) on the lipopolysaccharide (LPS) affinity for commercially pure titanium (cp-Ti) and Ti-6Al-4V alloy. Seventy-two titanium disks were anodically polarized in a controlled environment (n=9). Control specimens were not corroded. Deionized water with different concentrations of LPS (1.5, 15, and 150 μg/mL) were used to treat the disks for 24 hours to investigate LPS adherence (n=3). Then specimens were immersed in LPS-free water to evaluate LPS elution at 24, 48, and 72 hours. Data were analyzed by the 2-way, 3-way, and 3-way repeated measures ANOVA, t tests, and the Tukey honestly significant difference (HSD) tests (α=.05). A greater corrosion rate of cp-Ti and Ti-6Al-4V alloy and a higher LPS adherence to titanium surfaces (P<.05) were noted at acidic pH. The LPS affinity was higher for the Ti-6Al-4V alloy than for cp-Ti (P<.05). More LPS was eluted from titanium surfaces after a 24-hour interval. Lipopolysaccharide affinity for cp-Ti and Ti-6Al-4V alloy is influenced by the corrosion process. Copyright © 2013 Editorial Council for the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

Chronic exposure to indoxacarb and pulmonary expression of toll-like receptor-9 in mice.

PubMed

Kaur, Sandeep; Mukhopadhyay, C S; Sethi, R S

2016-11-01

Chronic exposure to indoxacarb and pulmonary expression of toll-like receptor 9 (TLR-9) in mice. In this study, healthy male Swiss albino mice (n=30) aging 8-10 weeks were used to evaluate TLR-9 expression in lungs of mice following indoxacarb exposure with and without lipopolysaccharide (LPS). Indoxacarb was administered orally dissolved in groundnut oil at 4 and 2 mg/kg/day for 90 days. On day 91, five animals from each group were challenged with LPS/normal saline solution at 80 µg/animal. The lung tissues were processed for real time and immunohistochemical studies. LPS resulted increase in fold change m-RNA expression level of TLR-9 as compare to control, while indoxacarb (4 mg/kg) alone and in combination with LPS resulted 16.21-fold change and 29.4-fold change increase in expression of TLR-9 m-RNA, respectively, as compared to control. Similarly, indoxacarb (2 mg/kg) alone or in combination with LPS also altered TLR-9 expression. Further at protein level control group showed minimal expression of TLR-9 in lungs as compare to other groups, however, LPS group showed intense positive staining in bronchial epithelium as well as in alveolar septal cells. Indoxacarb at both doses individually showed strong immuno-positive reaction as compare to control, however when combined with LPS resulted intense staining in airway epithelium as compare to control. Chronic oral administration of indoxacarb for 90 days (4 and 2 mg/kg) alters expression of TLR-9 at m-RNA and protein level and co-exposure with LPS exhibited synergistic effect.

6-Mercaptopurine attenuates tumor necrosis factor-α production in microglia through Nur77-mediated transrepression and PI3K/Akt/mTOR signaling-mediated translational regulation.

PubMed

Huang, Hsin-Yi; Chang, Hui-Fen; Tsai, Ming-Jen; Chen, Jhih-Si; Wang, Mei-Jen

2016-04-13

The pathogenesis of several neurodegenerative diseases often involves the microglial activation and associated inflammatory processes. Activated microglia release pro-inflammatory factors that may be neurotoxic. 6-Mercaptopurine (6-MP) is a well-established immunosuppressive drug. Common understanding of their immunosuppressive properties is largely limited to peripheral immune cells. However, the effect of 6-MP in the central nervous system, especially in microglia in the context of neuroinflammation is, as yet, unclear. Tumor necrosis factor-α (TNF-α) is a key cytokine of the immune system that initiates and promotes neuroinflammation. The present study aimed to investigate the effect of 6-MP on TNF-α production by microglia to discern the molecular mechanisms of this modulation. Lipopolysaccharide (LPS) was used to induce an inflammatory response in cultured primary microglia or murine BV-2 microglial cells. Released TNF-α was measured by enzyme-linked immunosorbent assay (ELISA). Gene expression was determined by real-time reverse transcription polymerase chain reaction (RT-PCR). Signaling molecules were analyzed by western blotting, and activation of NF-κB was measured by ELISA-based DNA binding analysis and luciferase reporter assay. Chromatin immunoprecipitation (ChIP) analysis was performed to examine NF-κB p65 and coactivator p300 enrichments and histone modifications at the endogenous TNF-α promoter. Treatment of LPS-activated microglia with 6-MP significantly attenuated TNF-α production. In 6-MP pretreated microglia, LPS-induced MAPK signaling, IκB-α degradation, NF-κB p65 nuclear translocation, and in vitro p65 DNA binding activity were not impaired. However, 6-MP suppressed transactivation activity of NF-κB and TNF-α promoter by inhibiting phosphorylation and acetylation of p65 on Ser276 and Lys310, respectively. ChIP analyses revealed that 6-MP dampened LPS-induced histone H3 acetylation of chromatin surrounding the TNF-α promoter, ultimately leading to a decrease in p65/coactivator-mediated transcription of TNF-α gene. Furthermore, 6-MP enhanced orphan nuclear receptor Nur77 expression. Using RNA interference approach, we further demonstrated that Nur77 upregulation contribute to 6-MP-mediated inhibitory effect on TNF-α production. Additionally, 6-MP also impeded TNF-α mRNA translation through prevention of LPS-activated PI3K/Akt/mTOR signaling cascades. These results suggest that 6-MP might have a therapeutic potential in neuroinflammation-related neurodegenerative disorders through downregulation of microglia-mediated inflammatory processes.

Endotoxin-induced shock in the rat. A role for C5a.

PubMed Central

Smedegård, G.; Cui, L. X.; Hugli, T. E.

1989-01-01

Administration of endotoxin from gram-negative bacteria to rats results in systemic hypotension, an increased hematocrit, and decreased numbers of circulating leukocytes (polymorphonuclear), monocytes, and platelets. These potentially lethal physiologic changes may be partially attributed to complement activation and generation of anaphylatoxins by the endotoxin (LPS). We demonstrated an elevation in the plasma levels of both C3a and C5a in LPS-treated rats. Injection of 5 micrograms C5ades Arg (rat) into rats produced effects similar to those induced by LPS, including decreased mean arterial pressure (systemic hypotension) and decreased numbers of circulating polymorphonuclear leukocytes, monocytes, and platelets. Unlike the response to LPS, C5a did not increase the hematocrit, indicating little effect on vascular permeability at the doses used. When LPS-treated animals were pretreated with F(ab')2 fragments of rabbit anti-rat C5a, no changes were measured in the circulating cell counts compared with LPS alone; however a significant improvement in the mean arterial pressure and a decrease in hematocrit was observed. We conclude that LPS-induced (septic) shock in the rat may result, in part, from the effects of complement activation and particularly from the generation of C5a. The influence of C5a on the LPS effect in the rat appears to enhance both the hypotensive (mean arterial pressure) and vascular permeability (hematocrit) responses. These results appear to support and confirm earlier observations that anti-human C5a increased survival in a septic-shock monkey model by eliminating circulating C5a and presumably thereby reducing the effects of endotoxin on blood pressure. Our results demonstrate that C5a plays a significant role in the hemodynamic changes associated with endotoxin-induced shock. Neutralization of C5a with specific antibodies may reduce the hypotensive response to endotoxin sufficiently to prevent lethal septic shock both in animals and in man. PMID:2789475

Melatonin protects against myocardial hypertrophy induced by lipopolysaccharide.

PubMed

Lu, Qi; Yi, Xin; Cheng, Xiang; Sun, Xiaohui; Yang, Xiangjun

2015-04-01

Melatonin is thought to have the ability of antiatherogenic, antioxidant, and vasodilatory. It is not only a promising protective in acute myocardial infarction but is also a useful tool in the treatment of pathological remodeling. However, its role in myocardial hypertrophy remains unclear. In this study, we investigated the protective effects of melatonin on myocardial hypertrophy induced by lipopolysaccharide (LPS) and to identify their precise mechanisms. The cultured myocardial cell was divided into six groups: control group, LPS group, LPS + ethanol (4%), LPS + melatonin (1.5 mg/ml) group, LPS + melatonin (3 mg/ml) group, and LPS + melatonin (6 mg/ml) group. The morphologic change of myocardial cell was observed by inverted phase contrast microscope. The protein level of myocardial cell was measured by Coomassie brilliant blue protein kit. The secretion level of tumor necrosis factor-α (TNF-α) was evaluated by enzyme-linked immunosorbent assay (ELISA). Ca(2+) transient in Fura-2/AM-loaded cells was measured by Till image system. The expression of Ca(2+)/calmodulin-dependent kinase II (CaMKII) and calcineurin (CaN) was measured by Western blot analysis. Our data demonstrated that LPS induced myocardial hypertrophy, promoted the secretion levels of TNF-α, and increased Ca(2+) transient level and the expression of CaMKII and CaN. Administration of melatonin 30 min prior to LPS stimulation dose-dependently attenuated myocardial hypertrophy. In conclusion, the results revealed that melatonin had the potential to protect against myocardial hypertrophy induced by LPS in vitro through downregulation of the TNF-α expression and retains the intracellular Ca(2+) homeostasis.

Biophysical mechanisms of endotoxin neutralization by cationic amphiphilic peptides.

PubMed

Kaconis, Yani; Kowalski, Ina; Howe, Jörg; Brauser, Annemarie; Richter, Walter; Razquin-Olazarán, Iosu; Iñigo-Pestaña, Melania; Garidel, Patrick; Rössle, Manfred; Martinez de Tejada, Guillermo; Gutsmann, Thomas; Brandenburg, Klaus

2011-06-08

Bacterial endotoxins (lipopolysaccharides (LPS)) are strong elicitors of the human immune system by interacting with serum and membrane proteins such as lipopolysaccharide-binding protein (LBP) and CD14 with high specificity. At LPS concentrations as low as 0.3 ng/ml, such interactions may lead to severe pathophysiological effects, including sepsis and septic shock. One approach to inhibit an uncontrolled inflammatory reaction is the use of appropriate polycationic and amphiphilic antimicrobial peptides, here called synthetic anti-LPS peptides (SALPs). We designed various SALP structures and investigated their ability to inhibit LPS-induced cytokine secretion in vitro, their protective effect in a mouse model of sepsis, and their cytotoxicity in physiological human cells. Using a variety of biophysical techniques, we investigated selected SALPs with considerable differences in their biological responses to characterize and understand the mechanism of LPS inactivation by SALPs. Our investigations show that neutralization of LPS by peptides is associated with a fluidization of the LPS acyl chains, a strong exothermic Coulomb interaction between the two compounds, and a drastic change of the LPS aggregate type from cubic into multilamellar, with an increase in the aggregate sizes, inhibiting the binding of LBP and other mammalian proteins to the endotoxin. At the same time, peptide binding to phospholipids of human origin (e.g., phosphatidylcholine) does not cause essential structural changes, such as changes in membrane fluidity and bilayer structure. The absence of cytotoxicity is explained by the high specificity of the interaction of the peptides with LPS. Copyright © 2011 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Complement reduction impairs the febrile response of guinea pigs to endotoxin.

PubMed

Sehic, E; Li, S; Ungar, A L; Blatteis, C M

1998-06-01

Although it is generally believed that circulating exogenous pyrogens [e.g., lipopolysaccharides (LPS)] induce fever via the mediation of endogenous pyrogens (EP) such as cytokines, the first of these, tumor necrosis factor-alpha, is usually not detectable in blood until at least 30 min after intravenous administration of LPS, whereas the febrile rise begins within 15 min after its administration. Moreover, although abundant evidence indicates that circulating LPS is cleared primarily by liver macrophages [Kupffer cells (KC)], these do not secrete EP in immediate response. This would imply that other factors, presumably evoked earlier than EP, may mediate the onset of the febrile response to intravenous LPS. It is well known that blood-borne LPS very rapidly activates the intravascular complement (C) system, some components of which in turn stimulate the quick release into blood of various substances that have roles in the acute inflammatory reaction. KC contain receptors for C components and are in close contact with afferent vagal terminals in the liver; the involvement of hepatic vagal afferents in LPS-induced fever has recently been shown. In this study, we tested the hypothesis that the initiation of fever by intravenous LPS involves, sequentially, the C system and KC. To test this postulated mechanism, we measured directly the levels of prostaglandin E2 (PGE2) in the interstitial fluid of the preoptic anterior hypothalamus (POA), the presumptive site of the fever-producing controller, of conscious guinea pigs over their entire febrile course, before and after C depletion by cobra venom factor (CVF) and before and after elimination of KC by gadolinium chloride (GdCl3). CVF and GdCl3 pretreatment each individually attenuated the first of the biphasic core temperature (Tc) rises after intravenous LPS, inverted the second into a Tc fall, and greatly reduced the usual fever-associated increase in POA PGE2. We conclude, therefore, that C activation may indeed be pivotal in the induction of fever by intravenous LPS and that substance(s) generated presumably by KC in almost immediate reaction to the presence of LPS and/or C may transmit pyrogenic signals via hepatic vagal afferents to the POA, where they rapidly induce the production of PGE2 and, hence, fever.

Differential regulation of CD44 expression by lipopolysaccharide (LPS) and TNF-alpha in human monocytic cells: distinct involvement of c-Jun N-terminal kinase in LPS-induced CD44 expression.

PubMed

Gee, Katrina; Lim, Wilfred; Ma, Wei; Nandan, Devki; Diaz-Mitoma, Francisco; Kozlowski, Maya; Kumar, Ashok

2002-11-15

Alterations in the regulation of CD44 expression play a critical role in modulating cell adhesion, migration, and inflammation. LPS, a bacterial cell wall component, regulates CD44 expression and may modulate CD44-mediated biological effects in monocytic cells during inflammation and immune responses. In this study, we show that in normal human monocytes, LPS and LPS-induced cytokines IL-10 and TNF-alpha enhance CD44 expression. To delineate the mechanism underlying LPS-induced CD44 expression, we investigated the role of the mitogen-activated protein kinases (MAPKs), p38, p42/44 extracellular signal-regulated kinase, and c-Jun N-terminal kinase (JNK) by using their specific inhibitors. We demonstrate the involvement, at least in part, of p38 MAPK in TNF-alpha-induced CD44 expression in both monocytes and promonocytic THP-1 cells. However, neither p38 nor p42/44 MAPKs were involved in IL-10-induced CD44 expression in monocytes. To further dissect the TNF-alpha and LPS-induced signaling pathways regulating CD44 expression independent of IL-10-mediated effects, we used IL-10 refractory THP-1 cells as a model system. Herein, we show that CD44 expression induced by the LPS-mediated pathway predominantly involved JNK activation. This conclusion was based on results derived by transfection of THP-1 cells with a dominant-negative mutant of stress-activated protein/extracellular signal-regulated kinase kinase 1, and by exposure of cells to JNK inhibitors dexamethasone and SP600125. All these treatments prevented CD44 induction in LPS-stimulated, but not in TNF-alpha-stimulated, THP-1 cells. Furthermore, we show that CD44 induction may involve JNK-dependent early growth response gene activation in LPS-stimulated monocytic cells. Taken together, these results suggest a predominant role of JNK in LPS-induced CD44 expression in monocytic cells.

Effects of voluntary wheel running on LPS-induced sickness behavior in aged mice.

PubMed

Martin, Stephen A; Pence, Brandt D; Greene, Ryan M; Johnson, Stephanie J; Dantzer, Robert; Kelley, Keith W; Woods, Jeffrey A

2013-03-01

Peripheral stimulation of the innate immune system with LPS causes exaggerated neuroinflammation and prolonged sickness behavior in aged mice. Regular moderate intensity exercise has been shown to exert anti-inflammatory effects that may protect against inappropriate neuroinflammation and sickness in aged mice. The purpose of this study was to test the hypothesis that voluntary wheel running would attenuate LPS-induced sickness behavior and proinflammatory cytokine gene expression in ~22-month-old C57BL/6J mice. Mice were housed with a running wheel (VWR), locked-wheel (Locked), or no wheel (Standard) for 10 weeks, after which they were intraperitoneally injected with LPS across a range of doses (0.02, 0.08, 0.16, 0.33 mg/kg). VWR mice ran on average 3.5 km/day and lost significantly more body weight and body fat, and increased their forced exercise tolerance compared to Locked and Shoebox mice. VWR had no effect on LPS-induced anorexia, adipsia, weight-loss, or reductions in locomotor activity at any LPS dose when compared to Locked and Shoebox groups. LPS induced sickness behavior in a dose-dependent fashion (0.33>0.02 mg/kg). Twenty-four hours post-injection (0.33 mg/kg LPS or Saline) we found a LPS-induced upregulation of whole brain TNFα, IL-1β, and IL-10 mRNA, and increased IL-1β and IL-6 in the spleen and liver; these effects were not attenuated by VWR. We conclude that VWR does not reduce LPS-induced exaggerated or prolonged sickness behavior in aged animals, or 24h post-injection (0.33 mg/kg LPS or Saline) brain and peripheral proinflammatory cytokine gene expression. The necessity of the sickness response is critical for survival and may outweigh the subtle benefits of exercise training in aged animals. Copyright © 2012 Elsevier Inc. All rights reserved.

NF-κB p65 Subunit Mediates Lipopolysaccharide-Induced Na+/I− Symporter Gene Expression by Involving Functional Interaction with the Paired Domain Transcription Factor Pax8

PubMed Central

Nicola, Juan Pablo; Nazar, Magalí; Mascanfroni, Iván Darío; Pellizas, Claudia Gabriela; Masini-Repiso, Ana María

2010-01-01

The Gram-negative bacterial endotoxin lipopolysaccharide (LPS) elicits a variety of biological responses. Na+/I− symporter (NIS)-mediated iodide uptake is the main rate-limiting step in thyroid hormonogenesis. We have recently reported that LPS stimulates TSH-induced iodide uptake. Here, we further analyzed the molecular mechanism involved in the LPS-induced NIS expression in Fisher rat thyroid cell line 5 (FRTL-5) thyroid cells. We observed an increase in TSH-induced NIS mRNA expression in a dose-dependent manner upon LPS treatment. LPS enhanced the TSH-stimulated NIS promoter activity denoting the NIS-upstream enhancer region (NUE) as responsible for the stimulatory effects. We characterized a novel putative conserved κB site for the transcription factor nuclear factor-κB (NF-κB) within the NUE region. NUE contains two binding sites for the transcription factor paired box 8 (Pax8), main regulator of NIS transcription. A physical interaction was observed between the NF-κB p65 subunit and paired box 8 (Pax8), which appears to be responsible for the synergic effect displayed by these transcription factors on NIS gene transcription. Moreover, functional blockage of NF-κB signaling and site-directed mutagenesis of the κB cis-acting element abrogated LPS stimulation. Silencing expression of p65 confirmed its participation as an effector of LPS-induced NIS stimulation. Furthermore, chromatin immunoprecipitation corroborated that NIS is a novel target gene for p65 transactivation in response to LPS. Moreover, we were able to corroborate the LPS-stimulatory effect on thyroid cells in vivo in LPS-treated rats, supporting that thyrocytes are capable of responding to systemic infections. In conclusion, our results reveal a new mechanism involving p65 in the LPS-induced NIS expression, denoting a novel aspect in thyroid cell differentiation. PMID:20667985

The ocular endothelin system: a novel target for the treatment of endotoxin-induced uveitis with bosentan.

PubMed

Keles, Sadullah; Halici, Zekai; Atmaca, Hasan Tarik; Yayla, Muhammed; Yildirim, Kenan; Ekinci, Metin; Akpinar, Erol; Altuner, Durdu; Cakici, Ozgur; Bayraktutan, Zafer

2014-05-15

We compared the anti-inflammatory effects of bosentan and dexamethasone in endotoxin-induced uveitis (EIU). Endotoxin-induced uveitis was induced by subcutaneous injection of lipopolysaccharide (LPS, 200 μg) in Wistar rats. Rats were divided randomly into 10 groups (n = 6). Bosentan at doses of 50 and 100 mg/kg were administered orally 1 hour before and 12 hours after LPS injection, and dexamethasone was administered by intraperitoneally 30 minutes before and 30 minutes after LPS injection at a dose of 1 mg/kg. Data were collected at two time points for each control and treatment; animals were killed at either 3 or 24 hours after LPS injection. Histopathologic evaluation and aqueous humour measurements of TNF-α level were performed, and endothelin-1 (ET-1), inducible nitric oxide synthase (iNOS), and endothelin receptor A and B (EDNRA and B) expression were analyzed. The group treated with 100 mg/kg bosentan at 24 hours displayed significantly milder uveitis and fewer inflammatory cells compared to LPS-injected animals, and there were similar findings in the dexamethasone-treated group at 24 hours. The TNF-α levels in the dexamethasone treatment group were lower than those in the LPS-induced uveitis control group (P < 0.05); however, there was no difference between the dexamethasone and bosentan treatment groups at 3 and 24 hours after LPS administration. Bosentan treatment at doses of 50 and 100 mg/kg significantly decreased iNOS expression compared to LPS-injected animals (P < 0.001). The ET-1 expression was suppressed significantly by bosentan and dexamethasone at 3 and 24 hours after LPS administration (P < 0.001). The EDNRA expression in the bosentan treatment groups was statistically significantly lower than that in the LPS-induced uveitis control group at 3 and 24 hours after LPS administration (P < 0.05). Bosentan reduces intraocular inflammation and has similar effects as dexamethasone in a rat model of EIU. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Endotoxins and other sepsis triggers.

PubMed

Opal, Steven M

2010-01-01

Endotoxin, or more accurately termed bacterial lipopolysaccharide (LPS), is recognized as the most potent microbial mediator implicated in the pathogenesis of sepsis and septic shock. Yet despite its discovery well over a century ago, the fundamental role of circulating endotoxin in the blood of most patients with septic shock remains enigmatic and a subject of considerable controversy. LPS is the most prominent 'alarm molecule' sensed by the host's early warning system of innate immunity presaging the threat of invasion of the internal milieu by Gram-negative bacterial pathogens. In small doses within a localized tissue space, LPS signaling is advantageous to the host in orchestrating an appropriate antimicrobial defense and bacterial clearance mechanisms. Conversely, the sudden release of large quantities of LPS into the bloodstream is clearly deleterious to the host, initiating the release of a dysregulated and potentially lethal array of inflammatory mediators and procoagulant factors in the systemic circulation. The massive host response to this single bacterial pattern recognition molecule is sufficient to generate diffuse endothelial injury, tissue hypoperfusion, disseminated intravascular coagulation and refractory shock. Numerous attempts to block endotoxin activity in clinical trials with septic patients have met with inconsistent and largely negative results. Yet the groundbreaking discoveries within the past decade into the precise molecular basis for LPS-mediated cellular activation and tissue injury has rekindled optimism that a new generation of therapies that specifically disrupt LPS signaling might succeed. Other microbial mediators found in Gram-positive bacterial and viral and fungal pathogens are now appreciated to activate many of the same host defense networks induced by LPS. This information is providing novel interventions in the continuing effots to improve the care of septic patients. Copyright 2010 S. Karger AG, Basel.

Flow Analysis of a Gas Turbine Low- Pressure Subsystem

NASA Technical Reports Server (NTRS)

Veres, Joseph P.

1997-01-01

The NASA Lewis Research Center is coordinating a project to numerically simulate aerodynamic flow in the complete low-pressure subsystem (LPS) of a gas turbine engine. The numerical model solves the three-dimensional Navier-Stokes flow equations through all components within the low-pressure subsystem as well as the external flow around the engine nacelle. The Advanced Ducted Propfan Analysis Code (ADPAC), which is being developed jointly by Allison Engine Company and NASA, is the Navier-Stokes flow code being used for LPS simulation. The majority of the LPS project is being done under a NASA Lewis contract with Allison. Other contributors to the project are NYMA and the University of Toledo. For this project, the Energy Efficient Engine designed by GE Aircraft Engines is being modeled. This engine includes a low-pressure system and a high-pressure system. An inlet, a fan, a booster stage, a bypass duct, a lobed mixer, a low-pressure turbine, and a jet nozzle comprise the low-pressure subsystem within this engine. The tightly coupled flow analysis evaluates aerodynamic interactions between all components of the LPS. The high-pressure core engine of this engine is simulated with a one-dimensional thermodynamic cycle code in order to provide boundary conditions to the detailed LPS model. This core engine consists of a high-pressure compressor, a combustor, and a high-pressure turbine. The three-dimensional LPS flow model is coupled to the one-dimensional core engine model to provide a "hybrid" flow model of the complete gas turbine Energy Efficient Engine. The resulting hybrid engine model evaluates the detailed interaction between the LPS components at design and off-design engine operating conditions while considering the lumped-parameter performance of the core engine.

A systems biology approach to the analysis of subset-specific responses to lipopolysaccharide in dendritic cells.

PubMed

Hancock, David G; Shklovskaya, Elena; Guy, Thomas V; Falsafi, Reza; Fjell, Chris D; Ritchie, William; Hancock, Robert E W; Fazekas de St Groth, Barbara

2014-01-01

Dendritic cells (DCs) are critical for regulating CD4 and CD8 T cell immunity, controlling Th1, Th2, and Th17 commitment, generating inducible Tregs, and mediating tolerance. It is believed that distinct DC subsets have evolved to control these different immune outcomes. However, how DC subsets mount different responses to inflammatory and/or tolerogenic signals in order to accomplish their divergent functions remains unclear. Lipopolysaccharide (LPS) provides an excellent model for investigating responses in closely related splenic DC subsets, as all subsets express the LPS receptor TLR4 and respond to LPS in vitro. However, previous studies of the LPS-induced DC transcriptome have been performed only on mixed DC populations. Moreover, comparisons of the in vivo response of two closely related DC subsets to LPS stimulation have not been reported in the literature to date. We compared the transcriptomes of murine splenic CD8 and CD11b DC subsets after in vivo LPS stimulation, using RNA-Seq and systems biology approaches. We identified subset-specific gene signatures, which included multiple functional immune mediators unique to each subset. To explain the observed subset-specific differences, we used a network analysis approach. While both DC subsets used a conserved set of transcription factors and major signalling pathways, the subsets showed differential regulation of sets of genes that 'fine-tune' the network Hubs expressed in common. We propose a model in which signalling through common pathway components is 'fine-tuned' by transcriptional control of subset-specific modulators, thus allowing for distinct functional outcomes in closely related DC subsets. We extend this analysis to comparable datasets from the literature and confirm that our model can account for cell subset-specific responses to LPS stimulation in multiple subpopulations in mouse and man.

Sickness behaviour after lipopolysaccharide treatment in ghrelin deficient mice.

PubMed

Szentirmai, Éva; Krueger, James M

2014-02-01

Ghrelin is an orexigenic hormone produced mainly by the gastrointestinal system and the brain. Much evidence also indicates a role for ghrelin in sleep and thermoregulation. Further, ghrelin was recently implicated in immune system modulation. Administration of bacterial lipopolysaccharide (LPS) induces fever, anorexia, and increased non-rapid-eye movement sleep (NREMS) and these actions are mediated primarily by proinflammatory cytokines. Ghrelin reduces LPS-induced fever, suppresses circulating levels of proinflammatory cytokines and reduces the severity and mortality of various models of experimental endotoxemia. In the present study, we determined the role of intact ghrelin signaling in LPS-induced sleep, feeding, and thermoregulatory responses in mice. Sleep-wake activity was determined after intraperitoneal, dark onset administration of 0.4, 2 and 10 μg LPS in preproghrelin knockout (KO) and wild-type (WT) mice. In addition, body temperature, motor activity and changes in 24-h food intake and body weight were measured. LPS induced dose-dependent increases in NREMS, and suppressed rapid-eye movement sleep, electroencephalographic slow-wave activity, motor activity, food intake and body weight in both Ppg KO and WT mice. Body temperature changes showed a biphasic pattern with a decrease during the dark period followed by an increase in the light phase. The effects of the low and middle doses of LPS were indistinguishable between the two genotypes. Administration of 10 μg LPS, however, induced significantly larger changes in NREMS and wakefulness amounts, body temperature, food intake and body weight in the Ppg KO mice. These findings support a role for ghrelin as an endogenous modulator of inflammatory responses and a central component of arousal and feeding circuits. Copyright © 2013 Elsevier Inc. All rights reserved.

Inflammation-induced pain sensitization in men and women: does sex matter in experimental endotoxemia?

PubMed Central

Wegner, Alexander; Elsenbruch, Sigrid; Rebernik, Laura; Roderigo, Till; Engelbrecht, Elisa; Jäger, Marcus; Engler, Harald; Schedlowski, Manfred; Benson, Sven

2015-01-01

Abstract A role of the innate immune system is increasingly recognized as a mechanism contributing to pain sensitization. Experimental administration of the bacterial endotoxin lipopolysaccharide (LPS) constitutes a model to study inflammation-induced pain sensitization, but all existing human evidence comes from male participants. We assessed visceral and musculoskeletal pain sensitivity after low-dose LPS administration in healthy men and women to test the hypothesis that women show greater LPS-induced hyperalgesia compared with men. In this randomized, double-blind, placebo-controlled crossover study, healthy men (n = 20) and healthy women using oral contraceptives (n = 20) received an intravenous injection of 0.4 ng/kg body weight LPS or placebo. Pain sensitivity was assessed with established visceral and musculoskeletal pain models (ie, rectal pain thresholds; pressure pain thresholds for different muscle groups), together with a heartbeat perception (interoceptive accuracy) task. Plasma cytokines (tumor necrosis factor-α and interleukin-6) were measured along with state anxiety at baseline and up to 6-hour postinjection. Lipopolysaccharide application led to significant increases in plasma cytokines and state anxiety and decreased interoceptive awareness in men and women (P < 0.001, condition effects), with more pronounced LPS-induced cytokine increases in women (P < 0.05, interaction effects). Although both rectal and pressure pain thresholds were significantly decreased in the LPS condition (all P < 0.05, condition effect), no sex differences in endotoxin-induced sensitization were observed. In summary, LPS-induced systemic immune activation leads to visceral and musculoskeletal hyperalgesia, irrespective of biological sex. These findings support the broad applicability of experimental endotoxin administration as a translational preclinical model of inflammation-induced pain sensitization in both sexes. PMID:26058036

Nature and mechanisms of hepatocyte apoptosis induced by D-galactosamine/lipopolysaccharide challenge in mice.

PubMed

Wu, Yi-Hang; Hu, Shao-Qing; Liu, Jun; Cao, Hong-Cui; Xu, Wei; Li, Yong-Jun; Li, Lan-Juan

2014-06-01

Apoptosis plays a role in the normal development of liver. However, overactivation thereof may lead to hepatocellular damage. The aim of this study was to assess D-galactosamine (D-GalN)/lipopolysaccharide (LPS)-induced hepatocyte apoptotic changes in mice and clarify the mechanisms involved in this process. DNA ladder detection was employed to determine the induction condition of hepatic apoptosis. An initial test indicated that typical hepatocyte apoptosis was observed at 6-10 h after the intraperitoneal injection of D-GalN (700 mg/kg) and LPS (10 µg/kg). Subsequently, we evaluated hepatocyte apoptosis at 8 h after administering D-GalN/LPS by histopathological analysis, terminal deoxynucleotidyl transferase-mediated dUTP nick end‑labeling (TUNEL) detection, flow cytometry and electron microscopy analysis. To clarify the apoptosis-related gene expression, the expression levels of tumor necrosis factor-α (TNF-α), transforming growth factor-β1 (TGF-β1), caspase-3, and Fas/Fas ligand (FasL) were determined by serum enzyme immunoassay, immunohistochemistry and western blot analysis. Strong apoptotic positive signals following D-GalN/LPS injection were observed from the results of the serum analysis, histopathological and immunohistochemical analyses, DNA ladder detection, TUNEL detection, flow cytometry and electron microscopy analysis. Additionally, apoptotic hepatocytes were mainly at the late stage of cell apoptosis. The expression of TNF-α, TGF-β1, caspase-3 and Fas/FasL was significantly increased. In conclusion, this study evaluated the D-GalN/LPS-induced hepatocyte apoptotic changes and clarified the apoptosis-related gene expression in mice. The hepatocyte apoptosis induced by D-GalN/LPS may be mainly regulated by the death receptor pathway. TGF-β signaling pathway may also play a vital role in this process of hepatocyte apoptosis.

Diverse action of lipoteichoic acid and lipopolysaccharide on neuroinflammation, blood-brain barrier disruption, and anxiety in mice.

PubMed

Mayerhofer, Raphaela; Fröhlich, Esther E; Reichmann, Florian; Farzi, Aitak; Kogelnik, Nora; Fröhlich, Eleonore; Sattler, Wolfgang; Holzer, Peter

2017-02-01

Microbial metabolites are known to affect immune system, brain, and behavior via activation of pattern recognition receptors such as Toll-like receptor 4 (TLR4). Unlike the effect of the TLR4 agonist lipopolysaccharide (LPS), the role of other TLR agonists in immune-brain communication is insufficiently understood. We therefore hypothesized that the TLR2 agonist lipoteichoic acid (LTA) causes immune activation in the periphery and brain, stimulates the hypothalamic-pituitary-adrenal (HPA) axis and has an adverse effect on blood-brain barrier (BBB) and emotional behavior. Since LTA preparations may be contaminated by LPS, an extract of LTA (LTA extract ), purified LTA (LTA pure ), and pure LPS (LPS ultrapure ) were compared with each other in their effects on molecular and behavioral parameters 3h after intraperitoneal (i.p.) injection to male C57BL/6N mice. The LTA extract (20mg/kg) induced anxiety-related behavior in the open field test, enhanced the circulating levels of particular cytokines and the cerebral expression of cytokine mRNA, and blunted the cerebral expression of tight junction protein mRNA. A dose of LPS ultrapure matching the amount of endotoxin/LPS contaminating the LTA extract reproduced several of the molecular and behavioral effects of LTA extract . LTA pure (20mg/kg) increased plasma levels of tumor necrosis factor-α (TNF-α), interleukin-6 and interferon-γ, and enhanced the transcription of TNF-α, interleukin-1β and other cytokines in the amygdala and prefrontal cortex. These neuroinflammatory effects of LTA pure were associated with transcriptional down-regulation of tight junction-associated proteins (claudin 5, occludin) in the brain. LTA pure also enhanced circulating corticosterone, but failed to alter locomotor and anxiety-related behavior in the open field test. These data disclose that TLR2 agonism by LTA causes peripheral immune activation and initiates neuroinflammatory processes in the brain that are associated with down-regulation of BBB components and activation of the HPA axis, although emotional behavior (anxiety) is not affected. The results obtained with an LTA preparation contaminated with LPS hint at a facilitatory interaction between TLR2 and TLR4, the adverse impact of which on long-term neuroinflammation, disruption of the BBB and mental health warrants further analysis. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

Time-resolved metabolomics analysis of individual differences during the early stage of lipopolysaccharide-treated rats.

PubMed

Dai, Die; Gao, Yiqiao; Chen, Jiaqing; Huang, Yin; Zhang, Zunjian; Xu, Fengguo

2016-10-03

Lipopolysaccharide (LPS) can lead to uncontrollable cytokine production and eventually cause fatal sepsis syndrome. Individual toxicity difference of LPS has been widely reported. In our study we observed that two thirds of the rats (24/36) died at a given dose of LPS, while the rest (12/36) survived. Tracking the dynamic metabolic change in survival and non-survival rats in the early stage may reveal new system information to understand the inter-individual variation in response to LPS. As the time-resolved datasets are very complex and no single method can elucidate the problem clearly and comprehensively, the static and dynamic metabolomics methods were employed in combination as cross-validation. Intriguingly, some common results have been observed. Lipids were the main different metabolites between survival and non-survival rats in pre-dose serum and in the early stage of infection with LPS. The LPS treatment led to S-adenosly-methionine and total cysteine individual difference in early stage, and subsequent significant perturbations in energy metabolism and oxidative stress. Furthermore, cytokine profiles were analyzed to identify potential biological associations between cytokines and specific metabolites. Our collective findings may provide some heuristic guidance for elucidating the underlying mechanism of individual difference in LPS-mediated disease.

Noradrenaline inhibits lipopolysaccharide-induced tumor necrosis factor and interleukin 6 production in human whole blood.

PubMed Central

van der Poll, T; Jansen, J; Endert, E; Sauerwein, H P; van Deventer, S J

1994-01-01

Sepsis and lipopolysaccharide (LPS) trigger the systemic release of both cytokines and catecholamines. Cytokines are known to be capable of eliciting a stress hormone response in vivo. The present study sought insight into the effect of noradrenaline on LPS-induced release of tumor necrosis factor alpha (TNF) and interleukin 6 (IL-6) in human whole blood. Whole blood was incubated with LPS for 4 h at 37 degrees C in the presence and absence of noradrenaline and/or specific alpha and beta antagonists and agonists. Noradrenaline caused a dose-dependent inhibition of LPS-induced TNF and IL-6 production. This effect could be completely prevented by addition of the specific beta 1, antagonist metoprolol, while it was not affected by the alpha antagonist phentolamine. Specific beta-adrenergic stimulation by isoprenaline mimicked the inhibiting effect of noradrenaline on LPS-evoked cytokine production, whereas alpha-adrenergic stimulation by phenylephrine had no effect. Fluorescence-activated cell sorter analysis demonstrated that beta-adrenergic stimulation had no effect on LPS binding to and internalization into mononuclear cells or on the expression of CD14, the major receptor for LPS on mononuclear cells. In acute sepsis, enhanced release of noradrenaline may be part of a negative feedback mechanism meant to inhibit ongoing TNF and IL-6 production. PMID:8168970

Neonatal immune challenge does not affect body weight regulation in rats.

PubMed

Spencer, Sarah J; Mouihate, Abdeslam; Galic, Michael A; Ellis, Shaun L; Pittman, Quentin J

2007-08-01

The perinatal environment plays a crucial role in programming many aspects of adult physiology. Myriad stressors during pregnancy, from maternal immune challenge to nutritional deficiency, can alter long-term body weight set points of the offspring. In light of the increasing concern over body weight issues, such as obesity and anorexia, in modern societies and accumulating evidence that developmental stressors have long-lasting effects on other aspects of physiology (e.g., fever, pain), we explored the role of immune system activation during neonatal development and its impact on body weight regulation in adulthood. Here we present a thorough evaluation of the effects of immune system activation (LPS, 100 microg/kg ip) at postnatal days 3, 7, or 14 on long-term body weight, adiposity, and body weight regulation after a further LPS injection (50 microg/kg ip) or fasting and basal and LPS-induced circulating levels of the appetite-regulating proinflammatory cytokine leptin. We show that neonatal exposure to LPS at various times during the neonatal period has no long-term effects on growth, body weight, or adiposity. We also observed no effects on body weight regulation in response to a short fasting period or a further exposure to LPS. Despite reductions in circulating leptin levels in response to LPS during the neonatal period, no long-term effects on leptin were seen. These results convincingly demonstrate that adult body weight and weight regulation are, unlike many other aspects of adult physiology, resistant to programming by a febrile-dose neonatal immune challenge.

Capture of lipopolysaccharide (endotoxin) by the blood clot: a comparative study.

PubMed

Armstrong, Margaret T; Rickles, Frederick R; Armstrong, Peter B

2013-01-01

In vertebrates and arthropods, blood clotting involves the establishment of a plug of aggregated thrombocytes (the cellular clot) and an extracellular fibrillar clot formed by the polymerization of the structural protein of the clot, which is fibrin in mammals, plasma lipoprotein in crustaceans, and coagulin in the horseshoe crab, Limulus polyphemus. Both elements of the clot function to staunch bleeding. Additionally, the extracellular clot functions as an agent of the innate immune system by providing a passive anti-microbial barrier and microbial entrapment device, which functions directly at the site of wounds to the integument. Here we show that, in addition to these passive functions in immunity, the plasma lipoprotein clot of lobster, the coagulin clot of Limulus, and both the platelet thrombus and the fibrin clot of mammals (human, mouse) operate to capture lipopolysaccharide (LPS, endotoxin). The lipid A core of LPS is the principal agent of gram-negative septicemia, which is responsible for more than 100,000 human deaths annually in the United States and is similarly toxic to arthropods. Quantification using the Limulus Amebocyte Lysate (LAL) test shows that clots capture significant quantities of LPS and fluorescent-labeled LPS can be seen by microscopy to decorate the clot fibrils. Thrombi generated in the living mouse accumulate LPS in vivo. It is suggested that capture of LPS released from gram-negative bacteria entrapped by the blood clot operates to protect against the disease that might be caused by its systemic dispersal.

UV-B affects the immune system and promotes nuclear abnormalities in pigmented and non-pigmented bullfrog tadpoles.

PubMed

Franco-Belussi, Lilian; Fanali, Lara Zácari; De Oliveira, Classius

2018-03-01

Ultra-Violet (UV) radiation is a stressor of the immune system and causes DNA damage. Leukocytes can change in response to environmental changes in anurans, making them an important biomarker of stressful situations. The initial barrier against UV in ectothermic animals is melanin-containing cells in skin and in their internal organs. Here, we tested the effects of UV exposure on immune cells and DNA integrity in pigmented and non-pigmented tadpoles of Lithobates catesbeianus. We used an inflammation model with lipopolysaccharide (LPS) of Escherichia coli to test synergic effects of UV and LPS. We tested the following hypotheses: 1) DNA damage caused by UV will be more pronounced in non-pigmented than in pigmented animals; 2) LPS increases leukocytes in both pigmented and non-pigmented animals by systemic inflammation; 3) The combined LPS and UV exposure will decrease the number of leukocytes. We found that the frequency of immune cells differed between pigmented and non-pigmented tadpoles. UV exposure increased mast cells and DNA damage in erythrocytes in both pigmented and non-pigmented tadpoles, while leukocytes decreased after UV exposure. Non-pigmented tadpoles experienced DNA damage and a lower lymphocyte count earlier than pigmented tadpoles. UV altered immune cells likely as a consequence of local and systemic inflammation. These alterations were less severe in pigmented than in non-pigmented animals. UV and LPS increased internal melanin in pigmented tadpoles, which were correlated with DNA damage and leukocytes. Here, we described for the first time the effects of UV and LPS in immune cells of pigmented and non-pigmented tadpoles. In addition, we demonstrated that internal melanin in tadpoles help in these defenses, since leukocyte responses were faster in non-pigmented animals, supporting the hypothesis that melanin is involved in the initial innate immune response. Copyright © 2018 Elsevier B.V. All rights reserved.

The contribution of hypothalamic neuroendocrine, neuroplastic and neuroinflammatory processes to lipopolysaccharide-induced depressive-like behaviour in female and male rats: Involvement of glucocorticoid receptor and C/EBP-β.

PubMed

Adzic, Miroslav; Djordjevic, Jelena; Mitic, Milos; Brkic, Zeljka; Lukic, Iva; Radojcic, Marija

2015-09-15

Peripheral inflammation induced by lipopolysaccharide (LPS) causes behavioural changes indicative for depression. The possible mechanisms involve the interference with neuroinflammatory, neuroendocrine, and neurotrophic processes. Apart from heterogeneity in the molecular background, sexual context may be another factor relevant to the manifestation of mood disturbances upon an immune challenge. We investigated sex-dependent effects of a 7-day LPS treatment of adult Wistar rats on depressive-like behaviour and their relation with hypothalamic neuroendocrine factor, corticotrophin-releasing hormone (CRH), proplastic brain-derived neurotropic factor (BDNF), pro-inflammatory cyclooxygenase-2 (COX-2) and nuclear factor kappa beta (NFkB). Also, their regulators, the glucocorticoid receptor (GR) and CCAAT enhancer-binding protein (C/EBP) β were followed. LPS induced depressive-like behaviour in females was associated with the increased hypothalamic CRH and decreased BDNF, but not with COX-2. These changes were paralleled by an increase in nuclear GR, NFkB and 20 kDa C/EBPβ. LPS also altered behaviour in males and increased CRH expression, but in contrast to females, this was accompanied with the elevated COX-2, accumulation of cytosolic GR and elevated nuclear 38 kDa C/EBPβ and NFkB. In conclusion, depressive-like phenotype induced by LPS in both sexes emerges from similar HPA axis activation and sex-specific alterations of hypothalamic molecular signalling: in males it is related to compromised control of neuroinflamation connected with cytoplasmic GR retention, while in females it is related to diminished proplastic capacity of BDNF. Sex-dependent mechanisms by which inflammation alters hypothalamic processes and cause pathological behaviour in animals, could be operative in the treatment of depression-related brain inflammation. Copyright © 2015 Elsevier B.V. All rights reserved.

Direct binding of Toll-like receptor 4 to ionotropic glutamate receptor N-methyl-D-aspartate subunit 1 induced by lipopolysaccharide in microglial cells N9 and EOC 20.

PubMed

Cui, Jie; Yu, Siyuan; Li, Yihui; Li, Pan; Liu, Feng

2018-03-01

Microglia, the primary immune cells in the brain, are the predominant cells regulating inflammation-mediated neuronal damage. In response to immunological challenges, such as lipopolysaccharide (LPS), microglia are activated and the inflammatory process is subsequently initiated. The aim of the present study was to determine whether LPS induces interactions between the Toll-like receptor 4 (TLR4) and the ionotropic glutamate receptor N-methyl-D‑aspartate subunit 1 (GluN1) in N9 and EOC 20 microglial cells. Immunocytochemistry demonstrated co-localization of TLR4 and GluN1 in response to LPS, and the direct binding of TLR4 and GluN1 was further validated by antibody-based Fluorescence Resonance Energy Transfer technology. Inhibition of the group I metabotropic glutamate receptor 5 with its selective antagonist, MTEP, abolished LPS-induced direct binding of TLR4 to GluN1. Therefore, these data demonstrated that GluN1 and TLR4 act reciprocally in response to LPS in N9 and EOC 20 microglial cells.

Docosahexaenoic acid-containing choline phospholipid modulates LPS-induced neuroinflammation in vivo and in microglia in vitro.

PubMed

Fourrier, Célia; Remus-Borel, Julie; Greenhalgh, Andrew D; Guichardant, Michel; Bernoud-Hubac, Nathalie; Lagarde, Michel; Joffre, Corinne; Layé, Sophie

2017-08-24

Neuroinflammatory processes are considered a double-edged sword, having both protective and detrimental effects in the brain. Microglia, the brain's resident innate immune cells, are a key component of neuroinflammatory response. There is a growing interest in developing drugs to target microglia and control neuroinflammatory processes. In this regard, docosahexaenoic acid (DHA), the brain's n-3 polyunsaturated fatty acid, is a promising molecule to regulate pro-inflammatory microglia and cytokine production. Several works reported that the bioavailability of DHA to the brain is higher when DHA is acylated to phospholipid. In this work, we analyzed the anti-inflammatory activity of DHA-phospholipid, either acetylated at the sn-1 position (AceDoPC, a stable form thought to have superior access to the brain) or acylated with palmitic acid at the sn-1 position (PC-DHA) using a lipopolysaccharide (LPS)-induced neuroinflammation model both in vitro and in vivo. In vivo, adult C57Bl6/J mice were injected intravenously (i.v.) with either AceDoPC or PC-DHA 24 h prior to LPS (i.p.). For in vitro studies, immortalized murine microglia cells BV-2 were co-incubated with DHA forms and LPS. AceDoPC and PC-DHA effect on brain or BV-2 PUFA content was assessed by gas chromatography. LPS-induced pro-inflammatory cytokines interleukin IL-1β, IL-6, and tumor necrosis factor (TNF) α production were measured by quantitative PCR (qPCR) or multiplex. IL-6 receptors and associated signaling pathway STAT3 were assessed by FACS analysis and western-blot in vitro. In vivo, a single injection of AceDoPC or PC-DHA decreased LPS-induced IL-6 production in the hippocampus of mice. This effect could be linked to their direct effect on microglia, as revealed in vitro. In addition, AceDoPC or PC-DHA reduced IL-6 receptor while only AceDoPC decreased IL-6-induced STAT3 phosphorylation. These results highlight the potency of administered DHA-acetylated to phospholipids-to rapidly regulate LPS-induced neuroinflammatory processes through their effect on microglia. In particular, both IL-6 production and signaling are targeted by AceDoPC in microglia.

Lipopolysaccharide inhibits the self-renewal of spermatogonial stem cells in vitro via downregulation of GDNF expression in Sertoli cells.

PubMed

Zhang, Xiaoli; Shi, Kun; Li, Yi; Zhang, Haiyu; Hao, Jing

2014-06-01

Lipopolysaccharide (LPS) can reduce sperm count and sperm quality. The molecular mechanisms underlying this process are not fully understood. In this report, we investigated the effects of LPS-treated Sertoli cells on self-renewal and differentiation of spermatogoinial stem cells (SSCs). Sertoli cell cultures were established and incubated with LPS (10μg/ml) for 1, 2 or 3 days, respectively. The culture media were collected and used as conditioned media (CM) to culture SSCs. The expression of glial cell-derived neurotrophic factor (GDNF), stem cell factor (SCF) and bone morphogenetic protein 4 (BMP4) in Sertoli cells treated with LPS was analyzed by RT-PCR and Western blotting. The results showed that the expression of SSC differentiation markers, c-kit and Sohlh2, was increased, while the expression of SSC self-renewal markers, plzf, oct4, and PCNA, was repressed when cultured in CM from LPS-treated Sertoli cells. GDNF levels in Sertoli cells and CM reduced dramatically after LPS treatments, while SCF and BMP4 levels did not show any significant changes. Moreover, correlated with the GDNF levels in CM, GDNF target genes, Bcl6b and Etv5, were reduced markedly in SSCs. Our results suggest that LPS inhibits the expression of GDNF in Sertoli cells, and might prevent the SSC self-renewal via down-regulation of GDNF target genes. Copyright © 2014 Elsevier Inc. All rights reserved.

Long term effects of lipopolysaccharide on satellite glial cells in mouse dorsal root ganglia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blum, E.; Procacci, P.; Conte, V.

Lipopolysaccharide (LPS) has been used extensively to study neuroinflammation, but usually its effects were examined acutely (24 h<). We have shown previously that a single intraperitoneal LPS injection activated satellite glial cells (SGCs) in mouse dorsal root ganglia (DRG) and altered several functional parameters in these cells for at least one week. Here we asked whether the LPS effects would persist for 1 month. We injected mice with a single LPS dose and tested pain behavior, assessed SGCs activation in DRG using glial fibrillary acidic protein (GFAP) immunostaining, and injected a fluorescent dye intracellularly to study intercellular coupling. Electron microscopymore » was used to quantitate changes in gap junctions. We found that at 30 days post-LPS the threshold to mechanical stimulation was lower than in controls. GFAP expression, as well as the magnitude of dye coupling among SGCs were greater than in controls. Electron microscopy analysis supported these results, showing a greater number of gap junctions and an abnormal growth of SGC processes. These changes were significant, but less prominent than at 7 days post-LPS. We conclude that a single LPS injection exerts long-term behavioral and cellular changes. The results are consistent with the idea that SGC activation contributes to hyperalgesia. - Highlights: • A single lipopolysaccharides injection activated glia in mouse dorsal root ganglia for 30 days. • This was accompanied by increased communications by gap junctions among glia and by hyperalgesia. • Glial activation and coupling may contribute to chronic pain.« less

Attenuation of Lipopolysaccharide-Induced Lung Vascular Stiffening by Lipoxin Reduces Lung Inflammation

PubMed Central

Meng, Fanyong; Mambetsariev, Isa; Tian, Yufeng; Beckham, Yvonne; Meliton, Angelo; Leff, Alan; Gardel, Margaret L.; Allen, Michael J.; Birukov, Konstantin G.

2015-01-01

Reversible changes in lung microstructure accompany lung inflammation, although alterations in tissue micromechanics and their impact on inflammation remain unknown. This study investigated changes in extracellular matrix (ECM) remodeling and tissue stiffness in a model of LPS-induced inflammation and examined the role of lipoxin analog 15-epi-lipoxin A4 (eLXA4) in the reduction of stiffness-dependent exacerbation of the inflammatory process. Atomic force microscopy measurements of live lung slices were used to directly measure local tissue stiffness changes induced by intratracheal injection of LPS. Effects of LPS on ECM properties and inflammatory response were evaluated in an animal model of LPS-induced lung injury, live lung tissue slices, and pulmonary endothelial cell (EC) culture. In vivo, LPS increased perivascular stiffness in lung slices monitored by atomic force microscopy and stimulated expression of ECM proteins fibronectin, collagen I, and ECM crosslinker enzyme, lysyl oxidase. Increased stiffness and ECM remodeling escalated LPS-induced VCAM1 and ICAM1 expression and IL-8 production by lung ECs. Stiffness-dependent exacerbation of inflammatory signaling was confirmed in pulmonary ECs grown on substrates with high and low stiffness. eLXA4 inhibited LPS-increased stiffness in lung cross sections, attenuated stiffness-dependent enhancement of EC inflammatory activation, and restored lung compliance in vivo. This study shows that increased local vascular stiffness exacerbates lung inflammation. Attenuation of local stiffening of lung vasculature represents a novel mechanism of lipoxin antiinflammatory action. PMID:24992633

Evidence for a bacterial lipopolysaccharide-recognizing G-protein-coupled receptor in the bacterial engulfment by Entamoeba histolytica.

PubMed

Brewer, Matthew T; Agbedanu, Prince N; Zamanian, Mostafa; Day, Tim A; Carlson, Steve A

2013-11-01

Entamoeba histolytica is the causative agent of amoebic dysentery, a worldwide protozoal disease that results in approximately 100,000 deaths annually. The virulence of E. histolytica may be due to interactions with the host bacterial flora, whereby trophozoites engulf colonic bacteria as a nutrient source. The engulfment process depends on trophozoite recognition of bacterial epitopes that activate phagocytosis pathways. E. histolytica GPCR-1 (EhGPCR-1) was previously recognized as a putative G-protein-coupled receptor (GPCR) used by Entamoeba histolytica during phagocytosis. In the present study, we attempted to characterize EhGPCR-1 by using heterologous GPCR expression in Saccharomyces cerevisiae. We discovered that bacterial lipopolysaccharide (LPS) is an activator of EhGPCR-1 and that LPS stimulates EhGPCR-1 in a concentration-dependent manner. Additionally, we demonstrated that Entamoeba histolytica prefers to engulf bacteria with intact LPS and that this engulfment process is sensitive to suramin, which prevents the interactions of GPCRs and G-proteins. Thus, EhGPCR-1 is an LPS-recognizing GPCR that is a potential drug target for treatment of amoebiasis, especially considering the well-established drug targeting to GPCRs.

Hematologic interactions of endotoxin, tumor necrosis factor alpha (TNF alpha), interleukin 1, and adrenal hormones and the hematologic effects of TNF alpha in Corynebacterium parvum-primed rats.

PubMed

Ulich, T R; del Castillo, J; Ni, R X; Bikhazi, N

1989-06-01

Endotoxin reduces the release among other cytokines of tumor necrosis factor (TNF) and interleukin 1 (IL-1) and causes peripheral lymphopenia and a dose-response-dependent initial neutropenia followed by a monophasic neutrophilia. TNF alone induces lymphopenia and an initial neutropenia followed by a biphasic neutrophilia. IL-1 alone induces lymphopenia and a monophasic neutrophilia. TNF-plus-IL-1 caused a greater lymphopenia than either monokine alone, suggesting that both monokines contribute to LPS-induced lymphopenia. TNF-plus-IL-1 induced neutropenia similar in magnitude to that induced by TNF alone and induced a neutrophilia significantly greater than that induced by either monokine alone, suggesting that LPS-induced neutropenia is caused by TNF, while LPS-induced neutrophilia is due to the combined effects of TNF and II-1. TNF and IL-1 were administered together with LPS to simulate the in vivo condition of endogenous monokine release during gram-negative bacteremia. TNF combined with LPS increased both the duration and magnitude of LPS-induced lymphopenia, LPS-induced neutropenia, and LPS-induced neutrophilia. TNF-plus-LPS treated rats at 2 hours after injection exhibited a striking 93% decrease in bone marrow neutrophils even though no peripheral neutrophilia was yet apparent, suggesting that the subsequent neutrophilia was due to demargination and recirculation of neutrophils sequestered in the peripheral vasculature immediately after their release from the bone marrow. Epinephrine, which causes neutrophilia by demargination but not by release of marrow neutrophils, reversed the initial neutropenia in TNF-plus-LPS-treated rats and increased the neutrophilia. IL-1 combined with LPS increased LPS-induced neutrophilia, suggesting that endogenous IL-1 also contributed to LPS-induced neutrophilia. Corynebacterium parvum-primed rats with hyperplasia of the monocyte-macrophage system and treated with TNF differed from naive rats treated with TNF in that the second peak was as great as the initial peak of neutrophilia, supporting the hypothesis that the second peak of TNF-induced neutrophilia is due to the release of endogenous monokines. In conclusion, exogenous TNF, IL-1, and adrenal hormones affect circulating numbers of lymphocytes and neutrophils in a fashion consistent with their postulated endogenous role in the regulation of leukocyte trafficking during bacterial infection.

Activation of PPARα by Wy-14643 ameliorates systemic lipopolysaccharide-induced acute lung injury

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoo, Seong Ho, E-mail: yoosh@snu.ac.kr; Abdelmegeed, Mohamed A.; Song, Byoung-Joon, E-mail: bj.song@nih.gov

Highlights: •Activation of PPARα attenuated LPS-mediated acute lung injury. •Pretreatment with Wy-14643 decreased the levels of IFN-γ and IL-6 in ALI. •Nitrosative stress and lipid peroxidation were downregulated by PPARα activation. •PPARα agonists may be potential therapeutic targets for acute lung injury. -- Abstract: Acute lung injury (ALI) is a major cause of mortality and morbidity worldwide. The activation of peroxisome proliferator-activated receptor-α (PPARα) by its ligands, which include Wy-14643, has been implicated as a potential anti-inflammatory therapy. To address the beneficial efficacy of Wy-14643 for ALI along with systemic inflammation, the in vivo role of PPARα activation was investigatedmore » in a mouse model of lipopolysaccharide (LPS)-induced ALI. Using age-matched Ppara-null and wild-type mice, we demonstrate that the activation of PPARα by Wy-14643 attenuated LPS-mediated ALI. This was evidenced histologically by the significant alleviation of inflammatory manifestations and apoptosis observed in the lung tissues of wild-type mice, but not in the corresponding Ppara-null mice. This protective effect probably resulted from the inhibition of LPS-induced increases in pro-inflammatory cytokines and nitroxidative stress levels. These results suggest that the pharmacological activation of PPARα might have a therapeutic effect on LPS-induced ALI.« less

nRGD modified lycobetaine and octreotide combination delivery system to overcome multiple barriers and enhance anti-glioma efficacy.

PubMed

Chen, Tijia; Song, Xu; Gong, Ting; Fu, Yao; Yang, Liuqing; Zhang, Zhirong; Gong, Tao

2017-08-01

For glioma as one of the most common and lethal primary brain tumors, the presence of BBB, BBTB, vasculogenic mimicry (VM) channels and tumor-associated macrophages (TAMs) are key biological barriers. Here, a novel drug delivery system which could efficiently deliver drugs to glioma by overcoming multi-barriers and increase antitumor efficacy through multi-therapeutic mechanisms was well developed. In this study, a multi-target peptide nRGD was used to transport across the BBB, mediate tumor penetration and target TAMs. Lycobetaine (LBT) was adopted to kill glioma cells and octreotide (OCT) was co-delivered to inhibit VM channels and prevent angiogenesis. LBT-OCT liposomes (LPs) showed controlled release profile in vitro, increased uptake efficiency, improved inhibitory effect against glioma cells and VM formation, and enhanced BBB-crossing capability. The median survival time of glioma-bearing mice administered with LBT-OCT LPs-nRGD was significantly longer than LBT-OCT LPs (P<0.01). Besides, nRGD achieved a stronger inhibitory effect against tumor associated macrophages (TAMs) compared to LPs-iRGD treatment groups in vivo. Thus, LPs-nRGD represented a promising versatile delivery platform for combination drug therapy in glioma treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

MiR-103 alleviates autophagy and apoptosis by regulating SOX2 in LPS-injured PC12 cells and SCI rats.

PubMed

Li, Guowei; Chen, Tao; Zhu, Yingxian; Xiao, Xiaoyu; Bu, Juyuan; Huang, Zongwen

2018-03-01

Recent studies revealed that microRNAs (miRNAs) may play crucial roles in the responses and pathologic processes of spinal cord injury (SCI). This study aimed to investigate the effect and the molecular basis of miR-103 on LPS-induced injuries in PC12 cells in vitro and SCI rats in vivo . PC12 cells were exposed to LPS to induce cell injuries to mimic the in vitro model of SCI. The expression of miR-103 and SOX2 in PC12 cells were altered by transient transfections. Cell viability and apoptotic cell rate were measured by CCK-8 assay and flow cytometry assay. Furthermore, Western blot analysis was performed to detect the expression levels of apoptosis- and autophagy- related proteins, MAPK/ERK pathway- and JAK/STAT pathway-related proteins. In addition, we also assessed the effect of miR-103 agomir on SCI rats. LPS exposure induced cell injuries in PC12 cells. miR-103 overexpression significantly increased cell viability, reduced cell apoptosis and autophagy, and opposite results were observed in miR-103 inhibition. miR-103 attenuated LPS-induced injuries by indirect upregulation of SOX2. SOX2 overexpression protected PC12 cells against LPS-induced injuries, while SOX2 inhibition expedited LPS-induced cell injuries. Furthermore, miR-103 overexpression inhibited MAPK/ERK pathway and JAK/STAT pathway through upregulation of SOX2. We also found that miR-103 agomir inhibited cell apoptosis and autophagy in SCI rats. This study demonstrates that miR-103 may represent a protective effect against cell apoptosis and autophagy in LPS-injured PC12 cells and SCI rats by upregulation of SOX2 expression.

Role of human amnion-derived mesenchymal stem cells in promoting osteogenic differentiation by influencing p38 MAPK signaling in lipopolysaccharide -induced human bone marrow mesenchymal stem cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Yuli; Wu, Hongxia; Shen, Ming

Periodontitis is a chronic inflammatory disease induced by bacterial pathogens, which not only affect connective tissue attachments but also cause alveolar bone loss. In this study, we investigated the anti-inflammatory effects of Human amnion-derived mesenchymal stem cells (HAMSCs) on human bone marrow mesenchymal stem cells (HBMSCs) under lipopolysaccharide (LPS)-induced inflammatory conditions. Proliferation levels were measured by flow cytometry and immunofluorescence staining of 5-ethynyl-2′-deoxyuridine (EdU). Osteoblastic differentiation and mineralization were investigated using chromogenic alkaline phosphatase activity (ALP) activity substrate assays, Alizarin red S staining, and RT-PCR analysis of HBMSCs osteogenic marker expression. Oxidative stress induced by LPS was investigated by assayingmore » reactive oxygen species (ROS) level and superoxide dismutase (SOD) activity. Here, we demonstrated that HAMSCs increased the proliferation, osteoblastic differentiation, and SOD activity of LPS-induced HBMSCs, and down-regulated the ROS level. Moreover, our results suggested that the activation of p38 MAPK signal transduction pathway is essential for reversing the LPS-induced bone-destructive processes. SB203580, a selective inhibitor of p38 MAPK signaling, significantly suppressed the anti-inflammatory effects in HAMSCs. In conclusion, HAMSCs show a strong potential in treating inflammation-induced bone loss by influencing p38 MAPK signaling. - Highlights: • LPS inhibites osteogenic differentiation in HBMSCs via suppression of p38 MAPK signaling pathway. • HAMSCs promote LPS-induced HBMSCs osteogenic differentiation through p38 MAPK signaling pathway. • HAMSCs reverse LPS-induced oxidative stress in LPS-induced HBMSCs through p38 MAPK signaling pathway.« less

Chronic exposure to indoxacarb and pulmonary expression of toll-like receptor-9 in mice

PubMed Central

Kaur, Sandeep; Mukhopadhyay, C. S.; Sethi, R. S.

2016-01-01

Aim: Chronic exposure to indoxacarb and pulmonary expression of toll-like receptor 9 (TLR-9) in mice. Materials and Methods: In this study, healthy male Swiss albino mice (n=30) aging 8-10 weeks were used to evaluate TLR-9 expression in lungs of mice following indoxacarb exposure with and without lipopolysaccharide (LPS). Indoxacarb was administered orally dissolved in groundnut oil at 4 and 2 mg/kg/day for 90 days. On day 91, five animals from each group were challenged with LPS/normal saline solution at 80 µg/animal. The lung tissues were processed for real time and immunohistochemical studies. Results: LPS resulted increase in fold change m-RNA expression level of TLR-9 as compare to control, while indoxacarb (4 mg/kg) alone and in combination with LPS resulted 16.21-fold change and 29.4-fold change increase in expression of TLR-9 m-RNA, respectively, as compared to control. Similarly, indoxacarb (2 mg/kg) alone or in combination with LPS also altered TLR-9 expression. Further at protein level control group showed minimal expression of TLR-9 in lungs as compare to other groups, however, LPS group showed intense positive staining in bronchial epithelium as well as in alveolar septal cells. Indoxacarb at both doses individually showed strong immuno-positive reaction as compare to control, however when combined with LPS resulted intense staining in airway epithelium as compare to control. Conclusion: Chronic oral administration of indoxacarb for 90 days (4 and 2 mg/kg) alters expression of TLR-9 at m-RNA and protein level and co-exposure with LPS exhibited synergistic effect. PMID:27956782

Fucoidan extracted from Fucus evanescens prevents endotoxin-induced damage in a mouse model of endotoxemia.

PubMed

Kuznetsova, Tatyana A; Besednova, Natalya N; Somova, Larisa M; Plekhova, Natalya G

2014-01-31

An important problem of treating patients with endotoxemia is to find drugs to reduce the negative effects of endotoxin on the organism. We tested fucoidan (sulfated polysaccharide) from the brown alga Fucus evanescens as a potential drug in a mouse model of endotoxemia inducted by lipopolysaccharide (LPS). The survival time of mice injected with LPS increased under fucoidan treatment compared with the group of mice injected with LPS only. The preventive administration of fucoidan to mice with endotoxemia resulted in inhibition of increased levels of proinflammatory cytokines (TNFα and IL-6), as well as decreasing of the processes of hypercoagulability. The parenteral or per os administration of fucoidan resulted in decreasing the degree of microcirculatory disorders and secondary dystrophic-destructive changes in parenchymal organs of mice with endotoxemia. Taken together, these results demonstrate that fucoidan prevents endotoxin-induced damage in a mouse model of endotoxemia and increases the mice's resistance to LPS.

Intestinal Alkaline Phosphatase Detoxifies Lipopolysaccharide and Prevents Inflammation in Response to the Gut Microbiota

PubMed Central

Bates, Jennifer M.; Akerlund, Janie; Mittge, Erika; Guillemin, Karen

2009-01-01

SUMMARY Vertebrates harbor abundant lipopolysaccharide (LPS) or endotoxin in their gut microbiota. Here we demonstrate that the brush border enzyme intestinal alkaline phosphatase (Iap), which dephosphorylates LPS, is induced during establishment of the microbiota and plays a crucial role in promoting mucosal tolerance to gut bacteria in zebrafish. We demonstrate that Iap deficient animals are hypersensitive to LPS toxicity through a mechanism mediated by Myd88 and Tumor Necrosis Factor Receptor (Tnfr). We further show that the endogenous microbiota establish the normal homeostatic level of neutrophils in the intestine through a process involving Myd88 and Tnfr. Iap deficient animals exhibit excessive intestinal neutrophil influx, similar to wild type animals exposed to LPS. When reared germ-free, however, the intestines of Iap deficient animals are devoid of neutrophils, demonstrating that Iap functions to prevent inflammatory responses to resident gut bacteria. PMID:18078689

Innate defense regulator peptide 1018 protects against perinatal brain injury.

PubMed

Bolouri, Hayde; Sävman, Karin; Wang, Wei; Thomas, Anitha; Maurer, Norbert; Dullaghan, Edie; Fjell, Christopher D; Ek, C Joakim; Hagberg, Henrik; Hancock, Robert E W; Brown, Kelly L; Mallard, Carina

2014-03-01

There is currently no pharmacological treatment that provides protection against brain injury in neonates. It is known that activation of an innate immune response is a key, contributing factor in perinatal brain injury; therefore, the neuroprotective therapeutic potential of innate defense regulator peptides (IDRs) was investigated. The anti-inflammatory effects of 3 IDRs was measured in lipopolysaccharide (LPS)-activated murine microglia. IDRs were then assessed for their ability to confer neuroprotection in vivo when given 3 hours after neonatal brain injury in a clinically relevant model that combines an inflammatory challenge (LPS) with hypoxia-ischemia (HI). To gain insight into peptide-mediated effects on LPS-induced inflammation and neuroprotective mechanisms, global cerebral gene expression patterns were analyzed in pups that were treated with IDR-1018 either 4 hours before LPS or 3 hours after LPS+HI. IDR-1018 reduced inflammatory mediators produced by LPS-stimulated microglia cells in vitro and modulated LPS-induced neuroinflammation in vivo. When administered 3 hours after LPS+HI, IDR-1018 exerted effects on regulatory molecules of apoptotic (for, eg, Fadd and Tnfsf9) and inflammatory (for, eg, interleukin 1, tumor necrosis factor α, chemokines, and cell adhesion molecules) pathways and showed marked protection of both white and gray brain matter. IDR-1018 suppresses proinflammatory mediators and cell injurious mechanisms in the developing brain, and postinsult treatment is efficacious in reducing LPS-induced hypoxic-ischemic brain damage. IDR-1018 is effective in the brain when given systemically, confers neuroprotection of both gray and white matter, and lacks significant effects on the brain under normal conditions. Thus, this peptide provides the features of a promising neuroprotective agent in newborns with brain injury. © 2014 Child Neurology Society/American Neurological Association.

Mechanical ventilation interacts with endotoxemia to induce extrapulmonary organ dysfunction

PubMed Central

O'Mahony, D Shane; Liles, W Conrad; Altemeier, William A; Dhanireddy, Shireesha; Frevert, Charles W; Liggitt, Denny; Martin, Thomas R; Matute-Bello, Gustavo

2006-01-01

Introduction Multiple organ dysfunction syndrome (MODS) is a common complication of sepsis in mechanically ventilated patients with acute respiratory distress syndrome, but the links between mechanical ventilation and MODS are unclear. Our goal was to determine whether a minimally injurious mechanical ventilation strategy synergizes with low-dose endotoxemia to induce the activation of pro-inflammatory pathways in the lungs and in the systemic circulation, resulting in distal organ dysfunction and/or injury. Methods We administered intraperitoneal Escherichia coli lipopolysaccharide (LPS; 1 μg/g) to C57BL/6 mice, and 14 hours later subjected the mice to 6 hours of mechanical ventilation with tidal volumes of 10 ml/kg (LPS + MV). Comparison groups received ventilation but no LPS (MV), LPS but no ventilation (LPS), or neither LPS nor ventilation (phosphate-buffered saline; PBS). Results Myeloperoxidase activity and the concentrations of the chemokines macrophage inflammatory protein-2 (MIP-2) and KC were significantly increased in the lungs of mice in the LPS + MV group, in comparison with mice in the PBS group. Interestingly, permeability changes across the alveolar epithelium and histological changes suggestive of lung injury were minimal in mice in the LPS + MV group. However, despite the minimal lung injury, the combination of mechanical ventilation and LPS resulted in chemical and histological evidence of liver and kidney injury, and this was associated with increases in the plasma concentrations of KC, MIP-2, IL-6, and TNF-α. Conclusion Non-injurious mechanical ventilation strategies interact with endotoxemia in mice to enhance pro-inflammatory mechanisms in the lungs and promote extra-pulmonary end-organ injury, even in the absence of demonstrable acute lung injury. PMID:16995930

Workplace ergonomics in lean production environments: A literature review.

PubMed

Arezes, Pedro M; Dinis-Carvalho, José; Alves, Anabela Carvalho

2015-01-01

Lean Production Systems (LPS) have become very popular among manufacturing industries, services and large commercial areas. A LPS must develop and consider a set of work features to bring compatibility with workplace ergonomics, namely at a muscular, cognitive and emotional demands level. Identify the most relevant impacts of the adoption of LPS from the ergonomics point of view and summarizes some possible drawbacks for workplace ergonomics due to a flawed application of the LPS. The impacts identified are focused in four dimensions: work pace, intensity and load; worker motivation, satisfaction and stress; autonomy and participation; and health outcome. This paper also discusses the influence that the work organization model has on workplace ergonomics and on the waste elimination previewed by LPS. Literature review focused LPS and its impact on occupational ergonomics conditions, as well as on the Health and Safety of workers. The main focus of this research is on LPS implementations in industrial environments and mainly in manufacturing industry workplaces. This is followed by a discussion including the authors' experience (and previous research). From the reviewed literature it seems that there is no consensus on how Lean principles affect the workplace ergonomics since most authors found positive (advantages) and negative (disadvantages) impacts. The negative impacts or disadvantages of LPS implementations reviewed may result from the misunderstanding of the Lean principles. Possibly, they also happen due to partial Lean implementations (when only one or two tools were implemented) that may be effective in a specific work context but not suitable to all possible situations as the principles of LPS should not lead, by definition, to any of the reported drawbacks in terms of workplace ergonomics.

[Effects of lipopolysaccharides from Porphyromonas endodontalis on the expression of MIP-1α in mouse osteoblasts].

PubMed

Yu, Ya-Qiong; Li, Xiao-Lin; Qiu, Li-Hong; Guo, Jia-Jie; Yang, Di; Guo, Yan

2017-06-01

To investigate the effects of lipopolysaccharides(LPS) extracted from Porphyromonas endodontalis(P.e) on the expression of macrophageinflammatoryprotein-1α (MIP-1α) mRNA and protein levels in MC3T3-E1 cells and the influence of curcumin in the process. MC3T3-E1 cells were treated with 20 mg/L P.e-LPS for different times (0-48 h). The expression of MIP-1α mRNA and protein was detected by real-time reverse transcription-polymerase chain reaction (real-time RT-PCR) and enzyme linked immunosorbent assay(ELISA). MC3T3-E1 cells were pretreated with inhibitor of (curcumin) for 1 h, and then treated with 20 mg/L P.e-LPS. The expression of MIP-1α was also detected by real-time RT-PCR and ELISA.Statistical analysis was performed using one-way ANOVA and Dunnett's t test with SPSS 13.0 software package. In the observation time (0-48 h), the impact of 20 P.e-LPS mg/L on induction of MIP-1α in MC3T3-El cells exhibited a time-dependent manner. The expression of MIP-1α mRNA and protein decreased significantly after pretreatment with 10 μmol/L curcumin for 1 h. The results suggest that P.e-LPS may mediate MIP-1α expression in MC3T3-E1 cells, and curcumin has a significant inhibitory effect on this process.

Effect of Sustained Postnatal Systemic Inflammation on Hippocampal Volume and Function in Mice

PubMed Central

Malaeb, Shadi N.; Davis, Jonathan M.; Pinz, Ilka M.; Newman, Jennifer L.; Dammann, Olaf; Rios, Maribel

2014-01-01

Background Premature infants are at risk for persistent neurodevelopmental impairment. Children born preterm often exhibit reduced hippocampal volumes that correlate with deficits in working memory. Perinatal inflammation is associated with preterm birth and brain abnormalities. Here we examine the effects of postnatal systemic inflammation on the developing hippocampus in mice. Methods Pups received daily intraperitoneal injections of lipopolysaccharide (LPS) or saline between days 3–13. Ex-vivo magnetic resonance imaging (MRI) and microscopic analysis of brain tissue was performed on day 14. Behavioral testing was conducted at 8–9 weeks of age. Results MR and microscopic analysis revealed a 15–20% reduction in hippocampal volume in LPS-treated mice compared to controls. Behavioral testing revealed deficits in hippocampal-related tasks in LPS-treated animals. Adult mice exposed to LPS during the postnatal period were unable to select a novel environment when re-placed within a 1-minute delay, were less able to remember a familiar object after a 1-hour delay and had impaired retention of associative fear learning after 24 hours. Conclusion Systemic inflammation sustained during the postnatal period contributes to reduced hippocampal volume and deficits in hippocampus-dependent working memory. These findings support the novel and emerging concept that sustained systemic inflammation contributes to neurodevelopmental impairment among preterm infants. PMID:25003911

[Effect of lipopolysaccharides from Porphyromonas endodontalis on the expression of macrophage colony stimulating factor in mouse osteoblasts].

PubMed

Yu, Yaqiong; Qiu, Lihong; Guo, Jiajie; Qu, Liu; Xu, Liya; Zhong, Ming

2014-09-01

To investigate the effects of lipopolysaccharides (LPS) extracted from Porphyromonas endodontalis (Pe) on the expression of macrophage colony stimulating factor (M-CSF) mRNA and protein in MC3T3-E1 cells and the role of nucler factor-κB (NF-κB) in the process. MC3T3-E1 cells were treated with different concentrations of Pe-LPS (0-50 mg/L) and 10 mg/L Pe-LPS for different hours (0-24 h). The expression of M-CSF mRNA and protein was detected by reverse transcription polymerase chain reaction (RT-PCR) and enzyme-linked immunoadsordent assay (ELISA). The cells untreated by Pe-LPS served as control. The expression of M- CSF mRNA and protein was also detected in 10 mg/L Pe- LPS treated MC3T3-E1 cells after pretreated with BAY 11-7082 for 1 h, a special NF-κB inhibitor. The groups were divided as follows, control group, BAY group (10 µmol/L BAY 11-7082 treated alone MC3T3-E1 cells), Pe-LPS group (10 mg/L Pe-LPS stimulated MC3T3-E1 cells for 6 h), BAY combine with Pe-LPS group (10 µmol/L BAY 11-7082 pretreated cells for 1 h and 10 mg/L of Pe-LPS stimulated MC3T3-E1 cells for 6 h). The level of M- CSF mRNA and protein increased significantly after treatment with different concentrations of Pe-LPS (0-50 mg/L), which indicated that Pe-LPS induced osteoblasts to express M-CSF mRNA and protein in dose dependent manners. The expression of M-CSF protein increased from (35 ± 2) ng/L (control group) to (170 ± 8) ng/L (50 mg/L group). Maximal induction of M-CSF mRNA expression was found in the MC3T3- E1 cells treated with 10 mg/L Pe-LPS for 6 h. After 6 h, the expression of M-CSF mRNA decreased gradually. The expression of M-CSF protein also increased with the treatment of 10 mg/L Pe-LPS for 10 h [(122 ± 4) ng/L]. After 10 h, the expression of M-CSF protein decreased gradually. The mRNA and proteins of M-CSF decreased significantly after pretreatment with 10 µmol/L BAY 11-7082 for 1 h. There was no significant difference between BAY group and the control. Pe-LPS may induce the expression of M-CSF mRNA and protein in MC3T3-E1 cells through the signaling of NF-κB.

Pro-oxidant activity of indicaxanthin from Opuntia ficus indica modulates arachidonate metabolism and prostaglandin synthesis through lipid peroxide production in LPS-stimulated RAW 264.7 macrophages

PubMed Central

Allegra, M.; D’Acquisto, F.; Tesoriere, L.; Attanzio, A.; Livrea, M.A.

2014-01-01

Macrophages come across active prostaglandin (PG) metabolism during inflammation, shunting early production of pro-inflammatory towards anti-inflammatory mediators terminating the process. This work for the first time provides evidence that a phytochemical may modulate the arachidonate (AA) metabolism in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages, promoting the ultimate formation of anti-inflammatory cyclopentenone 15deoxy-PGJ2. Added 1 h before LPS, indicaxanthin from Opuntia Ficus Indica prevented activation of nuclear factor-κB (NF-κB) and over-expression of PGE2 synthase-1 (mPGES-1), but up-regulated cyclo-oxygenase-2 (COX-2) and PGD2 synthase (H-PGDS), with final production of the anti-inflammatory cyclopentenone. The effects were positively related with concentration between 50 and 100 µM. Indicaxanthin did not have any effect in the absence of LPS. A kinetic study investigating the redox status of LPS-stimulated macrophages between 0.5 and 12 h, either in the absence or in the presence of 50–100 µM indicaxanthin, revealed a differential control of ROS production, with early (0.5–3 h) modest inhibition, followed by a progressive (3–12 h) concentration-dependent enhancement over the level induced by LPS alone. In addition, indicaxanthin caused early (0.5–3 h) concentration-dependent elevation of conjugated diene lipid hydroperoxides, and production of hydroxynonenal-protein adducts, over the amount induced by LPS. In LPS-stimulated macrophages indicaxanthin did not affect PG metabolism when co-incubated with either an inhibitor of NADPH oxidase or vitamin E. It is concluded that LPS-induced pro-oxidant activity of indicaxanthin at the membrane level allows formation of signaling intermediates whose accumulation modulates PG biosynthetic pathway in inflamed macrophages. PMID:25180166

Pro-oxidant activity of indicaxanthin from Opuntia ficus indica modulates arachidonate metabolism and prostaglandin synthesis through lipid peroxide production in LPS-stimulated RAW 264.7 macrophages.

PubMed

Allegra, M; D'Acquisto, F; Tesoriere, L; Attanzio, A; Livrea, M A

2014-01-01

Macrophages come across active prostaglandin (PG) metabolism during inflammation, shunting early production of pro-inflammatory towards anti-inflammatory mediators terminating the process. This work for the first time provides evidence that a phytochemical may modulate the arachidonate (AA) metabolism in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages, promoting the ultimate formation of anti-inflammatory cyclopentenone 15deoxy-PGJ2. Added 1 h before LPS, indicaxanthin from Opuntia Ficus Indica prevented activation of nuclear factor-κB (NF-κB) and over-expression of PGE2 synthase-1 (mPGES-1), but up-regulated cyclo-oxygenase-2 (COX-2) and PGD2 synthase (H-PGDS), with final production of the anti-inflammatory cyclopentenone. The effects were positively related with concentration between 50 and 100 µM. Indicaxanthin did not have any effect in the absence of LPS. A kinetic study investigating the redox status of LPS-stimulated macrophages between 0.5 and 12 h, either in the absence or in the presence of 50-100 µM indicaxanthin, revealed a differential control of ROS production, with early (0.5-3 h) modest inhibition, followed by a progressive (3-12 h) concentration-dependent enhancement over the level induced by LPS alone. In addition, indicaxanthin caused early (0.5-3 h) concentration-dependent elevation of conjugated diene lipid hydroperoxides, and production of hydroxynonenal-protein adducts, over the amount induced by LPS. In LPS-stimulated macrophages indicaxanthin did not affect PG metabolism when co-incubated with either an inhibitor of NADPH oxidase or vitamin E. It is concluded that LPS-induced pro-oxidant activity of indicaxanthin at the membrane level allows formation of signaling intermediates whose accumulation modulates PG biosynthetic pathway in inflamed macrophages.

Hypoxia preconditioning increases survival and decreases expression of Toll-like receptor 4 in pulmonary artery endothelial cells exposed to lipopolysaccharide

PubMed Central

Nanchal, Rahul; Audi, Said; Konduri, G. Ganesh; Medhora, Meetha

2013-01-01

Abstract Pulmonary or systemic infections and hypoxemic respiratory failure are among the leading causes of admission to intensive care units, and these conditions frequently exist in sequence or in tandem. Inflammatory responses to infections are reproduced by lipopolysaccharide (LPS) engaging Toll-like receptor 4 (TLR4). Apoptosis is a hallmark of lung injury in sepsis. This study was conducted to determine whether preexposure to LPS or hypoxia modulated the survival of pulmonary artery endothelial cells (PAECs). We also investigated the role TLR4 receptor expression plays in apoptosis due to these conditions. Bovine PAECs were cultured in hypoxic or normoxic environments and treated with LPS. TLR4 antagonist TAK-242 was used to probe the role played by TLR4 receptors in cell survival. Cell apoptosis and survival were measured by caspase 3 activity and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) incorporation. TLR4 expression and tumor necrosis factor α (TNF-α) production were also determined. LPS increased caspase 3 activity in a TAK-242-sensitive manner and decreased MTT incorporation. Apoptosis was decreased in PAECs preconditioned with hypoxia prior to LPS exposure. LPS increased TNF-α production, and hypoxic preconditioning blunted it. Hypoxic preconditioning reduced LPS-induced TLR4 messenger RNA and TLR4 protein. TAK-242 decreased to baseline the LPS-stimulated expression of TLR4 messenger RNA regardless of environmental conditions. In contrast, LPS followed by hypoxia substantially increased apoptosis and cell death. In conclusion, protection from LPS-stimulated PAEC apoptosis by hypoxic preconditioning is attributable in part to reduction in TLR4 expression. If these signaling pathways apply to septic patients, they may account for differing sensitivities of individuals to acute lung injury depending on oxygen tensions in PAECs in vivo. PMID:24618542

Molecular pathways mediating differential responses to lipopolysaccharide between human and baboon arterial endothelial cells.

PubMed

Shi, Qiang; Cox, Laura A; Glenn, Jeremy; Tejero, Maria E; Hondara, Vida; Vandeberg, John L; Wang, Xing Li

2010-02-01

1. Vascular inflammation plays a critical role in atherogenesis. Previously, we showed that baboon arterial endothelial cells (BAEC) were hyporesponsive to lipopolysaccharide (LPS) compared with human arterial endothelial cells (HAEC). 2. In the present study, we investigated mechanisms underlying differential responses between HAEC and BAEC to tumour necrosis factor (TNF)-alpha and LPS. 3. Both HAEC and BAEC responded similarly to TNF-alpha. However, BAEC showed retarded responses to LPS in expression of E-selectin, intercellular adhesion molecule-1, monocyte chemotactic protein-1 and interleukin-8 (P < 0.05). These changes were confirmed at the mRNA level. Tumour necrosis factor-alpha activated nuclear factor-kappaB members such as p50, p52, p65, c-rel and RelB in both HAEC and BAEC. In contrast, LPS activated p50 and p65 only in HAEC. Using microarray assays, we found that TNF receptor-associated factor 2 (TRAF-2), TNF receptor superfamily, member 1A-associated via death domain (TRADD) and nuclear factors such as nuclear factor of kappa in B-cells inhibitor, alpha (NFKBIA) and nuclear factor of kappa in B-cells inhibitor, beta (NFKBIB) were upregulated by LPS only in HAEC. Although the baseline expression of Toll-like receptor (TLR) 4 was low in both HAEC and BAEC, TNF-alpha activated TLR4 expression in both cell types. Although LPS increased TLR4 expression only in HAEC, human and baboon peripheral blood mononuclear cells exhibited similar TLR4 expression and response to LPS. Transfecting BAEC with TLR4/myeloid differentiation protein-2 overexpression vector conferred BAEC responsiveness to LPS. 4. The findings of the present study indicate that an altered TLR4 system may be responsible for the resistance of baboon endothelial cells to LPS. Given the importance of TLR4 in human immune responses and vascular diseases, the natural resistance of baboons to LPS/TLR4-initiated inflammation could make the baboon a valuable animal model in which to study how inflammation affects atherogenesis.

Protection Against Lipopolysaccharide-Induced Immunosuppression by IgG and IgM.

PubMed

Kyvelidou, Christiana; Sotiriou, Dimitris; Zerva, Ioanna; Athanassakis, Irene

2018-04-01

Lipopolysaccharide (LPS) is commonly used in murine sepsis models, which are largely associated with immunosuppression and collapse of the immune system. After adapting the LPS treatment to the needs of locally bred BALB/c mice, the present study explored the potential role of IgG and IgM in reversing LPS endotoxemia. The established protocol consisted of five daily intraperitoneal injections of 0.2 μg/g LPS, which was tolerable by half of the manipulated animals. Such a protocol allowed longer survival, necessary in the prospect of therapeutic treatment application. This treatment significantly decreased CD4+, CD8+, CD3z+, and CD19+ cells, while increasing myeloid-derived suppressor cells (MDSCs; CD11b+Gr1+), CD25+ and Foxp3+ cells. These results were accompanied by increased arginase-1 activity in spleen cell lysates and production of IL-6, TNF-α, IL-18, and C-reactive protein (CRP) in the serum. The applied LPS protocol did not alter serum procalcitonin levels. MDSCs isolated from the spleen of LPS-treated animals (LPS-MDSCs) decreased proliferation of naive T cells in coculture experiments. The application of IgG and IgM to the naive T cell/LPS-MDSCs cocultures significantly decreased CD25+, Foxp3+, and CD3z+ cells, indicating an anti-suppressive effect of immunoglobulins. The in vivo application of IgG and IgM significantly decreased the percent of CD11b+Gr1+, CD25+, Foxp3+ cells, and arginase-1 activity in the spleen of LPS-treated animals, while decreasing IL-6, TNF-α, and CRP levels in the serum, allowing survival to all animals tested. In conclusion, these results reveal a novel mode of action of IgG/IgM in LPS endotoxemia, strengthening thus the use of immunoglobulin treatment is septic patients.

Impaired Bone Resorption by Lipopolysaccharide In Vivo in Mice Deficient in the Prostaglandin E Receptor EP4 Subtype

PubMed Central

Sakuma, Yoko; Tanaka, Kiyoshi; Suda, Michio; Komatsu, Yasato; Yasoda, Akihiro; Miura, Masako; Ozasa, Ami; Narumiya, Shuh; Sugimoto, Yukihiko; Ichikawa, Atsushi; Ushikubi, Fumitaka; Nakao, Kazuwa

2000-01-01

In a previous study we showed that the involvement of EP4 subtype of the prostaglandin E (PGE) receptor is crucial for lipopolysaccharide (LPS)-induced osteoclast formation in vitro. The present study was undertaken to test whether EP4 is actually associated with LPS-induced bone resorption in vivo. In wild-type (WT) mice, osteoclast formation in vertebrae and tibiae increased 5 days after systemic LPS injection, and urinary excretion of deoxypyridinoline, a sensitive marker for bone resorption, statistically increased 10 days after injection. In EP4 knockout (KO) mice, however, LPS injection caused no significant changes in these parameters throughout the experiment. LPS exposure for 4 h strongly induced osteoclast differentiation factor (ODF) mRNA expression in primary osteoblastic cells (POB) both from WT and EP4 KO mice, and this expression was not inhibited by indomethacin, suggesting prostaglandin (PG) independence. LPS exposure for 24 h further induced ODF expression in WT POB, but not in EP4 KO POB. Indomethacin partially inhibited ODF expression in WT POB, but not in EP4 KO POB. These data suggest that ODF is induced both PG dependently and PG independently. LPS exposure for 24 h induced slightly greater osteoclastgenesis inhibitory factor (OCIF) mRNA expression in EP4 KO than in WT POB. These findings suggest that the reduced ODF expression and apparently increased OCIF expression also are responsible for the markedly reduced LPS-induced osteoclast formation in EP4 KO mice. Our results show that the EP4 subtype of the PGE receptor is involved in LPS-induced bone resorption in vivo also. Since LPS is considered to be largely involved in bacterially induced bone loss, such as in periodontitis and osteomyelitis, our study is expected to help broaden our understanding of the pathophysiology of these conditions. PMID:11083800

Defective Bone Repair in C57Bl6 Mice With Acute Systemic Inflammation.

PubMed

Behrends, D A; Hui, D; Gao, C; Awlia, A; Al-Saran, Y; Li, A; Henderson, J E; Martineau, P A

2017-03-01

Bone repair is initiated with a local inflammatory response to injury. The presence of systemic inflammation impairs bone healing and often leads to malunion, although the underlying mechanisms remain poorly defined. Our research objective was to use a mouse model of cortical bone repair to determine the effect of systemic inflammation on cells in the bone healing microenvironment. QUESTION/PURPOSES: (1) Does systemic inflammation, induced by lipopolysaccharide (LPS) administration affect the quantity and quality of regenerating bone in primary bone healing? (2) Does systemic inflammation alter vascularization and the number or activity of inflammatory cells, osteoblasts, and osteoclasts in the bone healing microenvironment? Cortical defects were drilled in the femoral diaphysis of female and male C57BL/6 mice aged 5 to 9 months that were treated with daily systemic injections of LPS or physiologic saline as control for 7 days. Mice were euthanized at 1 week (Control, n = 7; LPS, n = 8), 2 weeks (Control, n = 7; LPS, n = 8), and 6 weeks (Control, n = 9; LPS, n = 8) after surgery. The quantity (bone volume per tissue volume [BV/TV]) and microarchitecture (trabecular separation and thickness, porosity) of bone in the defect were quantified with time using microCT. The presence or activity of vascular endothelial cells (CD34), macrophages (F4/80), osteoblasts (alkaline phosphatase [ALP]), and osteoclasts (tartrate-resistant acid phosphatase [TRAP]) were evaluated using histochemical analyses. Only one of eight defects was bridged completely 6 weeks after surgery in LPS-injected mouse bones compared with seven of nine defects in the control mouse bones (odds ratio [OR], 0.04; 95% CI, 0.003-0.560; p = 0.007). The decrease in cortical bone in LPS-treated mice was reflected in reduced BV/TV (21% ± 4% vs 39% ± 10%; p < 0.01), increased trabecular separation (240 ± 36 μm vs 171 ± 29 μm; p < 0.01), decreased trabecular thickness (81 ± 18 μm vs 110 ± 22 μm; p = 0.02), and porosity (79% ± 4% vs 60% ± 10%; p < 0.01) at 6 weeks postoperative. Defective healing was accompanied by decreased CD34 (1.1 ± 0.6 vs 3.4 ± 0.9; p < 0.01), ALP (1.9 ± 0.9 vs 6.1 ± 3.2; p = 0.03), and TRAP (3.3 ± 4.7 vs 7.2 ± 4.0; p = 0.01) activity, and increased F4/80 (13 ± 2.6 vs 6.8 ± 1.7; p < 0.01) activity at 2 weeks postoperative. The results indicate that LPS-induced systemic inflammation reduced the amount and impaired the quality of bone regenerated in mouse femurs. The effects were associated with impaired revascularization, decreased bone turnover by osteoblasts and osteoclasts, and by increased catabolic activity by macrophages. Results from this preclinical study support clinical observations of impaired primary bone healing in patients with systemic inflammation. Based on our data, local administration of VEGF in the callus to stimulate revascularization, or transplantation of stem cells to enhance bone turnover represent potentially feasible approaches to improve outcomes in clinical practice.

Omentin protects against LPS-induced ARDS through suppressing pulmonary inflammation and promoting endothelial barrier via an Akt/eNOS-dependent mechanism.

PubMed

Qi, Di; Tang, Xumao; He, Jing; Wang, Daoxin; Zhao, Yan; Deng, Wang; Deng, Xinyu; Zhou, Guoqi; Xia, Jing; Zhong, Xi; Pu, Shenglan

2016-09-08

Acute respiratory distress syndrome (ARDS) is characterized by increased pulmonary inflammation and endothelial barrier permeability. Omentin has been shown to benefit obesity-related systemic vascular diseases; however, its effects on ARDS are unknown. In the present study, the level of circulating omentin in patients with ARDS was assessed to appraise its clinical significance in ARDS. Mice were subjected to systemic administration of adenoviral vector expressing omentin (Ad-omentin) and one-shot treatment of recombinant human omentin (rh-omentin) to examine omentin's effects on lipopolysaccharide (LPS)-induced ARDS. Pulmonary endothelial cells (ECs) were treated with rh-omentin to further investigate its underlying mechanism. We found that a decreased level of circulating omentin negatively correlated with white blood cells and procalcitonin in patients with ARDS. Ad-omentin protected against LPS-induced ARDS by alleviating the pulmonary inflammatory response and endothelial barrier injury in mice, accompanied by Akt/eNOS pathway activation. Treatment of pulmonary ECs with rh-omentin attenuated inflammatory response and restored adherens junctions (AJs), and cytoskeleton organization promoted endothelial barrier after LPS insult. Moreover, the omentin-mediated enhancement of EC survival and differentiation was blocked by the Akt/eNOS pathway inactivation. Therapeutic rh-omentin treatment also effectively protected against LPS-induced ARDS via the Akt/eNOS pathway. Collectively, these data indicated that omentin protects against LPS-induced ARDS by suppressing inflammation and promoting the pulmonary endothelial barrier, at least partially, through an Akt/eNOS-dependent mechanism. Therapeutic strategies aiming to restore omentin levels may be valuable for the prevention or treatment of ARDS.

Lipopolysaccharide hyporesponsiveness: protective or damaging response to the brain?

PubMed

Pardon, Marie Christine

2015-01-01

Lipopolysaccharide (LPS) endotoxins are widely used as experimental models of systemic bacterial infection and trigger robust inflammation by potently activating toll-like receptors 4 (TLR4) expressed on innate immune cells. Their ability to trigger robust neuroinflammation despite poor brain penetration can prove useful for the understanding of how inflammation induced by viral infections contributes to the pathogenesis of neurodegenerative diseases. A single LPS challenge often result in a blunted inflammatory response to subsequent stimulation by LPS and other TLR ligands, but the extent to which endotoxin tolerance occur in the brain requires further clarification. LPS is also thought to render the brain transiently resistant to subsequent brain injuries by attenuating the concomitant pro-inflammatory response. While LPS hyporesponsiveness and preconditioning are classically seen as protective mechanisms limiting the toxic effects of sustained inflammation, recent research casts doubt as to whether they have beneficial or detrimental roles on the brain and in neurodegenerative disease. These observations suggest that spatio-temporal aspects of the immune responses to LPS and the disease status are determinant factors. Endotoxin tolerance may lead to a late pro-inflammatory response with potential harmful consequences. And while reduced TLR4 signaling reduces the risk of neurodegenerative diseases, up-regulation of anti-inflammatory cytokines associated with LPS hyporesponsiveness can have deleterious consequences to the brain by inhibiting the protective phenotype of microglia, aggravating the progression of some neurodegenerative conditions such as Alzheimer's disease. Beneficial effects of LPS preconditioning, however appear to require a stimulation of anti-inflammatory mediators rather than an attenuation of the pro-inflammatory response.

Potential down-regulation of salivary gland AQP5 by LPS via cross-coupling of NF-kappaB and p-c-Jun/c-Fos.

PubMed

Yao, Chenjuan; Purwanti, Nunuk; Karabasil, Mileva Ratko; Azlina, Ahmad; Javkhlan, Purevjav; Hasegawa, Takahiro; Akamatsu, Tetsuya; Hosoi, Toru; Ozawa, Koichiro; Hosoi, Kazuo

2010-08-01

The mRNA and protein levels of aquaporin (AQP)5 in the parotid gland were found to be potentially decreased by lipopolysaccharide (LPS) in vivo in C3H/HeN mice, but only weakly in C3H/HeJ, a TLR4 mutant mouse strain. In the LPS-injected mice, pilocarpine-stimulated saliva production was reduced by more than 50%. In a tissue culture system, the LPS-induced decrease in the AQP5 mRNA level was blocked completely by pyrrolidine dithiocarbamate, MG132, tyrphostin AG126, SP600125, and partially by SB203580, which are inhibitors for IkappaB kinase, 26S proteasome, ERK1/2, JNK, and p38 MAPK, respectively. In contrast, the expression of AQP1 mRNA was down-regulated by LPS and such down-regulation was blocked only by SP600125. The transcription factors NF-kappaB (p65 subunit), p-c-Jun, and c-Fos were increased by LPS given in vivo, whereas the protein-binding activities of the parotid gland extract toward the sequences for NF-kappaB but not AP-1-responsive elements present at the promoter region of the AQP5 gene were increased by LPS injection. Co-immunoprecipitation by using antibody columns suggested the physical association of the three transcription factors. These results suggest that LPS-induced potential down-regulation of expression of AQP5 mRNA in the parotid gland is mediated via a complex(es) of these two classes of transcription factors, NF-kappaB and p-c-Jun/c-Fos.

The role of lipopolysaccharide injected systemically in the reactivation of collagen-induced arthritis in mice

PubMed Central

Yoshino, Shin; Ohsawa, Motoyasu

2000-01-01

We investigated the role of bacterial lipopolysaccharide (LPS) in the reactivation of autoimmune disease by using collagen-induced arthritis (CIA) in mice in which autoimmunity to the joint cartilage component type II collagen (CII) was involved.CIA was induced by immunization with CII emulsified with complete Freund's adjuvant at the base of the tail (day 0) followed by a booster injection on day 21. Varying doses of LPS from E. coli were i.p. injected on day 50.Arthritis began to develop on day 25 after immunization with CII and reached a peak on day 35. Thereafter, arthritis subsided gradually but moderate joint inflammation was still observed on day 50. An i.p. injection of LPS on day 50 markedly reactivated arthritis on a dose-related fashion. Histologically, on day 55, there were marked oedema of synovium which had proliferated by the day of LPS injection, new formation of fibrin, and intense infiltration of neutrophils accompanied with a large number of mononuclear cells. The reactivation of CIA by LPS was associated with increases in anti-CII IgG and IgG2a antibodies as well as various cytokines including IL-12, IFN-γ, IL-1β, and TNF-α. LPS from S. enteritidis, S. typhimurium, and K. neumoniae and its component, lipid A from E. coli also reactivated the disease. Polymyxin B sulphate suppressed LPS- or lipid A-induced reactivation of CIA.These results suggest that LPS may play an important role in the reactivation of autoimmune joint inflammatory diseases such as rheumatoid arthritis in humans. PMID:10742285

Phase 1 testing of detoxified LPS/group B meningococcal outer membrane protein vaccine with and without synthetic CPG 7909 adjuvant for the prevention and treatment of sepsis.

PubMed

Cross, Alan S; Greenberg, Nancy; Billington, Melissa; Zhang, Lei; DeFilippi, Christopher; May, Ryan C; Bajwa, Kanwaldeep K

2015-11-27

Gram-negative bacteria (GNB) are a leading cause of nosocomial infection and sepsis. Increasing multi-antibiotic resistance has left clinicians with fewer therapeutic options. Antibodies to GNB lipopolysaccharide (LPS, or endotoxin) have reduced morbidity and mortality as a result of infection and are not subject to the resistance mechanisms deployed by bacteria against antibiotics. In this phase 1 study, we administered a vaccine that elicits antibodies against a highly conserved portion of LPS with and without a CpG oligodeoxynucleotide (ODN) TLR9 agonist as adjuvant. A vaccine composed of the detoxified LPS (dLPS) from E. coli O111:B4 (J5 mutant) non-covalently complexed to group B meningococcal outer membrane protein (OMP). Twenty healthy adult subjects received three doses at 0, 29 and 59 days of antigen (10 μg dLPS) with or without CPG 7909 (250 or 500 μg). Subjects were evaluated for local and systemic adverse effects and laboratory findings. Anti-J5 LPS IgG and IgM antibody levels were measured by electrochemiluminesence. Due to premature study termination, not all subjects received all three doses. All vaccine formulations were well-tolerated with no local or systemic events of greater than moderate severity. The vaccine alone group achieved a ≥ 4-fold "responder" response in IgG and IgM antibody in only one of 6 subjects. In contrast, the vaccine plus CPG 7909 groups appeared to have earlier and more sustained (to 180 days) responses, greater mean-fold increases, and a higher proportion of "responders" achieving ≥ 4-fold increases over baseline. Although the study was halted before all enrolled subjects received all three doses, the J5dLPS/OMP vaccine, with or without CpG adjuvant, was safe and well-tolerated. The inclusion of CpG increased the number of subjects with a ≥ 4-fold antibody response, evident even after the second of three planned doses. A vaccine comprising J5dLPS/OMP antigen with CpG adjuvant merits further investigation. ClinicalTrials.gov Identifier: NCT01164514. Copyright © 2015 Elsevier Ltd. All rights reserved.

Resveratrol counteracts lipopolysaccharide-mediated microglial inflammation by modulating a SOCS-1 dependent signaling pathway.

PubMed

Dragone, Teresa; Cianciulli, Antonia; Calvello, Rosa; Porro, Chiara; Trotta, Teresa; Panaro, Maria Antonietta

2014-09-01

Brain damage or exposure to inflammatory agents provokes the activation of microglia and secretion of pro-inflammatory and neurotoxic mediators responsible for neuronal loss. Several lines of evidence show that resveratrol, a natural non-flavonoid polyphenol, may exert a neuroprotective action in neurodegenerative diseases. Suppressor of cytokine signaling (SOCS) proteins are a family of eight members expressed by immune cells and the central nervous system (CNS) cells, that regulate immune processes within the CNS, including microglia activation. We demonstrate that resveratrol had anti-inflammatory effects in murine N13 microglial cells stimulated with lipopolysaccharide (LPS), through up-regulating SOCS-1 expression. Interestingly, in SOCS-1-silenced cells resveratrol failed to play a protective role after LPS treatment. Our data demonstrate that resveratrol can impair microglia activation by activating a SOCS-1 mediated signaling pathway. Copyright © 2014 Elsevier Ltd. All rights reserved.

Neonatal systemic inflammation in rats alters retinal vessel development and simulates pathologic features of retinopathy of prematurity.

PubMed

Hong, Hye Kyoung; Lee, Hyun Ju; Ko, Jung Hwa; Park, Ji Hyun; Park, Ji Yeon; Choi, Chang Won; Yoon, Chang-Hwan; Ahn, Seong Joon; Park, Kyu Hyung; Woo, Se Joon; Oh, Joo Youn

2014-05-15

Alteration of retinal angiogenesis during development leads to retinopathy of prematurity (ROP) in preterm infants, which is a leading cause of visual impairment in children. A number of clinical studies have reported higher rates of ROP in infants who had perinatal infections or inflammation, suggesting that exposure of the developing retina to inflammation may disturb retinal vessel development. Thus, we investigated the effects of systemic inflammation on retinal vessel development and retinal inflammation in neonatal rats. To induce systemic inflammation, we intraperitoneally injected 100 μl lipopolysaccharide (LPS, 0.25 mg/ml) or the same volume of normal saline in rat pups on postnatal days 1, 3, and 5. The retinas were extracted on postnatal days 7 and 14, and subjected to assays for retinal vessels, inflammatory cells and molecules, and apoptosis. We found that intraperitoneal injection of LPS impaired retinal vessel development by decreasing vessel extension, reducing capillary density, and inducing localized overgrowth of abnormal retinal vessels and dilated peripheral vascular ridge, all of which are characteristic findings of ROP. Also, a large number of CD11c+ inflammatory cells and astrocytes were localized in the lesion of abnormal vessels. Further analysis revealed that the number of major histocompatibility complex (MHC) class IIloCD68loCD11bloCD11chi cells in the retina was higher in LPS-treated rats compared to controls. Similarly, the levels of TNF-α, IL-1β, and IL-12a were increased in LPS-treated retina. Also, apoptosis was increased in the inner retinal layer where retinal vessels are located. Our data demonstrate that systemic LPS-induced inflammation elicits retinal inflammation and impairs retinal angiogenesis in neonatal rats, implicating perinatal inflammation in the pathogenesis of ROP.

Fractalkine receptor (CX3CR1) deficiency sensitizes mice to the behavioral changes induced by lipopolysaccharide

PubMed Central

2010-01-01

Background Interactions between fractalkine (CX3CL1) and fractalkine receptor (CX3CR1) regulate microglial activation in the CNS. Recent findings indicate that age-associated impairments in CX3CL1 and CX3CR1 are directly associated with exaggerated microglial activation and an impaired recovery from sickness behavior after peripheral injection of lipopolysaccharide (LPS). Therefore, the purpose of this study was to determine the extent to which an acute LPS injection causes amplified and prolonged microglial activation and behavioral deficits in CX3CR1-deficient mice (CX3CR1-/-). Methods CX3CR1-/- mice or control heterozygote mice (CX3CR1+/-) were injected with LPS (0.5 mg/kg i.p.) or saline and behavior (i.e., sickness and depression-like behavior), microglial activation, and markers of tryptophan metabolism were determined. All data were analyzed using Statistical Analysis Systems General Linear Model procedures and were subjected to one-, two-, or three-way ANOVA to determine significant main effects and interactions. Results LPS injection caused a prolonged duration of social withdrawal in CX3CR1-/- mice compared to control mice. This extended social withdrawal was associated with enhanced mRNA expression of IL-1β, indolamine 2,3-dioxygenase (IDO) and kynurenine monooxygenase (KMO) in microglia 4 h after LPS. Moreover, elevated expression of IL-1β and CD14 was still detected in microglia of CX3CR1-/- mice 24 h after LPS. There was also increased turnover of tryptophan, serotonin, and dopamine in the brain 24 h after LPS, but these increases were independent of CX3CR1 expression. When submitted to the tail suspension test 48 and 72 h after LPS, an increased duration of immobility was evident only in CX3CR1-/- mice. This depression-like behavior in CX3CR1-/- mice was associated with a persistent activated microglial phenotype in the hippocampus and prefrontal cortex. Conclusions Taken together, these data indicate that a deficiency of CX3CR1 is permissive to protracted microglial activation and prolonged behavioral alterations in response to transient activation of the innate immune system. PMID:21167054

SIRT2 ameliorates lipopolysaccharide-induced inflammation in macrophages

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Ae Sin; Jung, Yu Jin; Kim, Dal

2014-08-08

Highlights: • Knockout of SIRT2 attenuates lipopolysaccharide-induced iNOS expression. • Lipopolysaccharide-induced NO production is decreased in SIRT2 KO macrophage. • SIRT2 deficiency suppresses lipopolysaccharide-induced ROS production in macrophage. • M1-macrophage related factors are decreased in SIRT2 deficient cells. • SIRT2 deficiency decreases lipopolysaccharide-induced activation of NFκB. - Abstract: Introduction: SIRT2 is a NAD(+)-dependent deacetylases and associated with numerous processes such as infection, carcinogenesis, DNA damage and cell cycle regulation. However, the role of SIRT2 in inflammatory process in macrophage remains unclear. Materials and methods: In the present study, we have evaluated the regulatory effects of SIRT2 in lipopolysaccharide (LPS)-stimulated macrophagesmore » isolated from SIRT2 knockout (KO) and wild type (WT) mice or Raw264.7 macrophage cells. As inflammatory parameters, expression of inducible nitric oxide synthase (iNOS), the productions of nitric oxide, reactive oxygen species (ROS) and M1-macrophage-related factors were evaluated. We also examined the effects of SIRT2 on activation of nuclear factor-kappaB (NFκB) signaling. Results: SIRT2 deficiency inhibits LPS-induced iNOS mRNA and protein expression in bone marrow derived macrophages. SIRT2-siRNA transfection also suppressed LPS-induced iNOS expression in Raw264.7 macrophage cells. Bone marrow derived macrophages isolated from SIRT2 KO mice produced lower nitric oxide and expressed lower levels of M1-macrophage related markers including iNOS and CD86 in response to LPS than WT mice. Decrease of SIRT2 reduced the LPS-induced reactive oxygen species production. Deficiency of SIRT2 resulted in inhibition of NFκB activation through reducing the phosphorylation and degradation of IκBα. The phosphorylation and nuclear translocation of p65 was significantly decreased in SIRT2-deficient macrophages after LPS stimulation. Discussion: Our data suggested that deficiency of SIRT2 ameliorates iNOS, NO expression and reactive oxygen species production with suppressing LPS-induced activation of NFκB in macrophages.« less

Lipopolysaccharide induces proliferation and osteogenic differentiation of adipose-derived mesenchymal stromal cells in vitro via TLR4 activation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Herzmann, Nicole; Salamon, Achim; Fiedler, Tomas

Multipotent mesenchymal stromal cells (MSC) are capable of multi-lineage differentiation and support regenerative processes. In bacterial infections, resident MSC can come intocontact with and need to react to bacterial components. Lipopolysaccharide (LPS), a typical structure of Gram-negative bacteria, increases the proliferation and osteogenic differentiation of MSC. LPS is usually recognized by the toll-like receptor (TLR) 4 and induces pro-inflammatory reactions in numerous cell types. In this study, we quantified the protein expression of TLR4 and CD14 on adipose-derived MSC (adMSC) in osteogenic differentiation and investigated the effect of TLR4 activation by LPS on NF-κB activation, proliferation and osteogenic differentiation ofmore » adMSC. We found that TLR4 is expressed on adMSC whereas CD14 is not, and that osteogenic differentiation induced an increase of the amount of TLR4 protein whereas LPS stimulation did not. Moreover, we could show that NF-κB activation via TLR4 occurs upon LPS treatment. Furthermore, we were able to show that competitive inhibition of TLR4 completely abolished the stimulatory effect of LPS on the proliferation and osteogenic differentiation of adMSC. In addition, the inhibition of TLR4 leads to the complete absence of osteogenic differentiation of adMSC, even when osteogenically stimulated. Thus, we conclude that LPS induces proliferation and osteogenic differentiation of adMSC in vitro through the activation of TLR4 and that the TLR4 receptor seems to play a role during osteogenic differentiation of adMSC.« less

The Transcriptomic Response of Rat Hepatic Stellate Cells to Endotoxin: Implications for Hepatic Inflammation and Immune Regulation

PubMed Central

Tandon, Ashish; Gandhi, Chandrashekhar R.

2013-01-01

With their location in the perisinusoidal space of Disse, hepatic stellate cells (HSCs) communicate with all of the liver cell types both by physical association (cell body as well as cytosolic processes penetrating into sinusoids through the endothelial fenestrations) and by producing several cytokines and chemokines. Bacterial lipopolysaccharide (LPS), circulating levels of which are elevated in liver diseases and transplantation, stimulates HSCs to produce increased amounts of cytokines and chemokines. Although recent research provides strong evidence for the role of HSCs in hepatic inflammation and immune regulation, the number of HSC-elaborated inflammatory and immune regulatory molecules may be much greater then known at the present time. Here we report time-dependent changes in the gene expression profile of inflammatory and immune-regulatory molecules in LPS-stimulated rat HSCs, and their validation by biochemical analyses. LPS strongly up-regulated LPS-response elements (TLR2 and TLR7) but did not affect TLR4 and down-regulated TLR9. LPS also up-regulated genes in the MAPK, NFκB, STAT, SOCS, IRAK and interferon signaling pathways, numerous CC and CXC chemokines and IL17F. Interestingly, LPS modulated genes related to TGFβ and HSC activation in a manner that would limit their activation and fibrogenic activity. The data indicate that LPS-stimulated HSCs become a major cell type in regulating hepatic inflammatory and immunological responses by altering expression of numerous relevant genes, and thus play a prominent role in hepatic pathophysiology including liver diseases and transplantation. PMID:24349206

miR-217 regulates ethanol-induced hepatic inflammation by disrupting sirtuin 1-lipin-1 signaling.

PubMed

Yin, Huquan; Liang, Xiaomei; Jogasuria, Alvin; Davidson, Nicholas O; You, Min

2015-05-01

Ethanol-mediated injury, combined with gut-derived lipopolysaccharide (LPS), provokes generation of proinflammatory cytokines in Kupffer cells, causing hepatic inflammation. Among the mediators of these effects, miR-217 aggravates ethanol-induced steatosis in hepatocytes. However, the role of miR-217 in ethanol-induced liver inflammation process is unknown. Here, we examined the role of miR-217 in the responses to ethanol, LPS, or a combination of ethanol and LPS in RAW 264.7 macrophages and in primary Kupffer cells. In macrophages, ethanol substantially exacerbated LPS-mediated induction of miR-217 and production of proinflammatory cytokines compared with LPS or ethanol alone. Consistently, ethanol administration to mice led to increases in miR-217 abundance and increased production of inflammatory cytokines in isolated primary Kupffer cells exposed to the combination of ethanol and LPS. miR-217 promoted combined ethanol and LPS-mediated inhibition of sirtuin 1 expression and activity in macrophages. Moreover, miR-217-mediated sirtuin 1 inhibition was accompanied by increased activities of two vital inflammatory regulators, NF-κB and the nuclear factor of activated T cells c4. Finally, adenovirus-mediated overexpression of miR-217 led to steatosis and inflammation in mice. These findings suggest that miR-217 is a pivotal regulator involved in ethanol-induced hepatic inflammation. Strategies to inhibit hepatic miR-217 could be a viable approach in attenuating alcoholic hepatitis. Copyright © 2015 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Lipopolysaccharide and cAMP modify placental calcitriol biosynthesis reducing antimicrobial peptides gene expression.

PubMed

Olmos-Ortiz, Andrea; García-Quiroz, Janice; Avila, Euclides; Caldiño-Soto, Felipe; Halhali, Ali; Larrea, Fernando; Díaz, Lorenza

2018-06-01

Calcitriol, the hormonal form of vitamin D 3 (VD), stimulates placental antimicrobial peptides expression; nonetheless, the regulation of calcitriol biosynthesis in the presence of bacterial products and its consequence on placental innate immunity have scarcely been addressed. We investigated how some bacterial products modify placental VD metabolism and its ability to induce antimicrobial peptides gene expression. Cultured human trophoblasts biosynthesized calcitriol only in the presence of its precursor calcidiol, a process that was inhibited by cyclic-AMP but stimulated by lipopolysaccharide (LPS). Intracrine calcitriol upregulated cathelicidin, S100A9, and β-defensins (HBDs) gene expression, while LPS further stimulated HBD2 and S100A9. Unexpectedly, LPS significantly repressed cathelicidin basal mRNA levels and drastically diminished calcidiol ability to induce it. Meanwhile, cyclic-AMP, which is used by many microbes to avoid host defenses, suppressed calcitriol biosynthesis, resulting in significant inhibition of most VD-dependent microbicidal peptides gene expression. While LPS stimulated calcitriol biosynthesis, cyclic-AMP inhibited it. LPS downregulated cathelicidin mRNA expression, whereas cyclic-AMP antagonized VD-dependent-upregulation of most antimicrobial peptides. These findings reveal LPS and cyclic-AMP involvement in dampening placental innate immunity, highlighting the importance of cyclic-AMP in the context of placental infection and suggesting its participation to facilitate bacterial survival. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Granzyme M and K release in human experimental endotoxemia.

PubMed

Wensink, Annette C; Wiewel, Maryse A; Jongeneel, Lieneke H; Boes, Marianne; van der Poll, Tom; Hack, C Erik; Bovenschen, Niels

2016-07-01

Granzymes are serine proteases involved in killing of tumor cells and virally infected cells. However, granzymes are also upregulated in blood under inflammatory conditions and contribute to cytokine release and processing. Here, we show that granzyme M (GrM) and to a lesser extent GrK are transiently elevated in the circulation following LPS administration in humans. GrM is released upon stimulation of whole blood with LPS or the gram-negative bacteria Escherichia coli BL21, Pseudomonas aeruginosa, and Neisseria meningitidis. GrK is only released upon stimulation with P. aeruginosa. Thus, GrM and GrK are differentially released in response to LPS and gram-negative bacteria. Copyright © 2016 Elsevier GmbH. All rights reserved.

Effect of inflammatory challenge on hypothalamic neurons expressing orexinergic and melanin-concentrating hormone.

PubMed

Palomba, Maria; Seke Etet, Paul Faustin; Veronesi, Carlo

2014-06-06

Neurons containing the hypothalamic peptides orexin-A (hypocretin 1) and melanin-concentrating hormone (MCH) have been reported numerous roles in the regulation of the sleep-wake cycle, energy balance and feeding behavior. We investigated the response of these cells to repeated administration of low doses of endotoxin lipopolysaccharide (LPS) in mice. Adult male C57/6J mice where intraperitoneally (i.p.) injected with either LPS or phosphate-buffered saline (PBS) weekly for either 4 or 8 weeks, and afterwards were sacrificed at different time intervals from last injection. A significant drop in orexin-containing neuron number, but not in numbers of MCH or neuronal nuclear antigen (NeuN)-immunoreactive neurons, was observed after 8 weeks of LPS treatment, as compared to PBS treatment. Orexin expression entirely returned to control levels 30 days after the last LPS injection in mice treated for 8 weeks. These data strongly suggest the occurrence of selective alterations of orexinergic system, reversible over time, following repeated and intermittent systemic inflammatory challenge in mice. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Dopamine-dependent neurotoxicity of lipopolysaccharide in substantia nigra.

PubMed

De Pablos, Rocío M; Herrera, Antonio J; Villarán, Ruth F; Cano, Josefina; Machado, Alberto

2005-03-01

Intranigral injection of lipopolysaccharide (LPS), a potent inductor of inflammation, induces degeneration of dopaminergic neurons, along with an inflammatory process that features activation of microglial cells and loss of astrocytes. To test the involvement of dopamine (DA) in this degeneration induced by LPS, we treated albino Wistar rats with different concentrations of alpha-methyl-p-tyrosine (alpha-MPT), an inhibitor of tyrosine hydroxylase (TH) activity. Results showed that alpha-MPT prevented LPS-induced loss of TH immunostaining and expression of mRNA for TH and DA transporter; it also prevented substantial activation of microglial cells. Loss of the astroglial population, a marker of damage in our model, was also prevented. This protective effect resulted from inhibition of TH and the consequent decrease in DA concentration, because treatment with L-DOPA/benserazide, which bypasses TH inhibition induced by alpha-MPT, reversed the protective effect produced by this drug. These results point out the important contribution of DA to the vulnerability and degeneration of dopaminergic neurons of the substantia nigra. Knowledge about the involvement of DA in this process may lead to the possibility of new protection strategies against this important degenerative process.

The influence of polymer architectures on the dewetting behavior of thin polymer films: from linear chains to ring chains.

PubMed

Wang, Lina; Xu, Lin; Liu, Binyuan; Shi, Tongfei; Jiang, Shichun; An, Lijia

2017-05-03

The dewetting behavior of ring polystyrene (RPS) film and linear polystyrene (LPS) film on silanized Si substrates with different grafting densities and PDMS substrate was investigated. Results showed that polymer architectures greatly influenced the dewetting behavior of the thin polymer film. On the silanized Si substrate with 69% grafting density, RPS chains exhibited stronger adsorption compared with LPS chains, and as a result the wetting layer formed more easily. For LPS films, with a decreased annealing temperature, the stability of the polymer film changed from non-slip dewetting via apparent slip dewetting to apparently stable. However, for RPS films, the polymer film stability switched from apparent slip dewetting to apparently stable. On the silanized Si substrate with 94% grafting density, the chain adsorption became weaker and the dewetting processes were faster than that on the substrate with 69% grafting density at the same experimental temperature for both the LPS and RPS films. Moreover, on the PDMS substrate, LPS films always showed non-slip dewetting, while the dewetting kinetics of RPS films switched from non-slip dewetting to slip dewetting behaviour. Forming the wetting layer strongly influenced the stability and dewetting behavior of the thin polymer films.

Suppression of LPS-induced inflammatory responses by the hydroxyl groups of dexamethasone

PubMed Central

Chuang, Ting-Yun; Cheng, An-Jie; Chen, I-Ting; Lan, Tien-Yun; Huang, I-Hsuan; Shiau, Chung-Wai; Hsu, Chia-Lin; Liu, Ya-Wen; Chang, Zee-Fen; Tseng, Ping-Hui; Kuo, Jean-Cheng

2017-01-01

The innate immune response is a central process that is activated during pathogenic infection in order to maintain physiological homeostasis. It is well known that dexamethasone (Dex), a synthetic glucocorticoid, is a potent immunosuppressant that inhibits the cytokine production induced by bacterial lipopolysaccharides (LPS). Nevertheless, the extent to which the functional groups of Dex control the excessive activation of inflammatory reactions remains unknown. Furthermore, importantly, the role of Dex in the innate immune response remains unclear. Here we explore the mechanism of LPS-induced TNF-α secretion and reveal p38 MAPK signaling as a target of Dex that is involved in control of tumor necrosis factor-α (TNF-α)-converting enzyme (TACE) activity; that later mediates the shedding of TNF-α that allows its secretion. We further demonstrate that the 11-hydroxyl and 21-hydroxyl groups of Dex are the main groups that are involved in reducing LPS-induced TNF-α secretion by activated macrophages. Blockage of the hydroxyl groups of Dex inhibits immunosuppressant effect of Dex during LPS-induced TNF-α secretion and mouse mortality. Our findings demonstrate Dex signaling is involved in the control of innate immunity. PMID:28537905

Detoxifying Escherichia coli for endotoxin-free production of recombinant proteins.

PubMed

Mamat, Uwe; Wilke, Kathleen; Bramhill, David; Schromm, Andra Beate; Lindner, Buko; Kohl, Thomas Andreas; Corchero, José Luis; Villaverde, Antonio; Schaffer, Lana; Head, Steven Robert; Souvignier, Chad; Meredith, Timothy Charles; Woodard, Ronald Wesley

2015-04-16

Lipopolysaccharide (LPS), also referred to as endotoxin, is the major constituent of the outer leaflet of the outer membrane of virtually all Gram-negative bacteria. The lipid A moiety, which anchors the LPS molecule to the outer membrane, acts as a potent agonist for Toll-like receptor 4/myeloid differentiation factor 2-mediated pro-inflammatory activity in mammals and, thus, represents the endotoxic principle of LPS. Recombinant proteins, commonly manufactured in Escherichia coli, are generally contaminated with endotoxin. Removal of bacterial endotoxin from recombinant therapeutic proteins is a challenging and expensive process that has been necessary to ensure the safety of the final product. As an alternative strategy for common endotoxin removal methods, we have developed a series of E. coli strains that are able to grow and express recombinant proteins with the endotoxin precursor lipid IVA as the only LPS-related molecule in their outer membranes. Lipid IVA does not trigger an endotoxic response in humans typical of bacterial LPS chemotypes. Hence the engineered cells themselves, and the purified proteins expressed within these cells display extremely low endotoxin levels. This paper describes the preparation and characterization of endotoxin-free E. coli strains, and demonstrates the direct production of recombinant proteins with negligible endotoxin contamination.

Escherichia coli K1-induced cytopathogenicity of human brain microvascular endothelial cells.

PubMed

Khan, Naveed Ahmed; Iqbal, Junaid; Siddiqui, Ruqaiyyah

2012-01-01

Pathophysiology of Escherichia coli sepsis is complex involving circulating bacterial products, cytokine release, and sustained bacteremia resulting in the damage of vascular endothelium. Here, it is shown that E. coli K1 produced cytopathogenicity of human brain microvascular endothelial cells (HBMEC), that constitute the blood-brain barrier. Whole bacteria or their conditioned medium produced severe HBMEC damage suggesting E. coli K1-cytopathogenicity is a contact-independent process. Using lipopolysaccharide (LPS) inhibitor, polymyxin B, purified LPS extracted from E. coli K1 as well as LPS mutant derived from E. coli K1, we showed that LPS is not the sole determinant of E. coli K1-mediated HBMEC death. Bacterial product(s) for HBMEC cytopathogenicity was heat-labile suggesting LPS-associated proteins. Several isogenic gene-deletion mutants (ΔompA, ΔibeA, ΔibeB, Δcnf1) exhibited HBMEC cytopathogenicity similar to that produced by wild type E. coli K1. E. coli K1-mediated HBMEC death was independent of phosphatidylinositol 3-kinase (PI3K) but dependent partially on focal adhesion kinase (FAK) using HBMEC expressing dominant negative FAK and PI3K. Copyright © 2012 Elsevier Ltd. All rights reserved.

5-HT2A receptors control body temperature in mice during LPS-induced inflammation via regulation of NO production.

PubMed

Voronova, Irina P; Khramova, Galina M; Kulikova, Elizabeth A; Petrovskii, Dmitrii V; Bazovkina, Daria V; Kulikov, Alexander V

2016-01-01

G protein-coupled 5-HT2A receptors are involved in the regulation of numerous normal and pathological physiological functions. At the same time, its involvement in the regulation of body temperature (Tb) in normal conditions is obscure. Here we study the effect of the 5-HT2A receptor activation or blockade on Tb in sick animals. The experiments were carried out on adult C57BL/6 mouse males. Systemic inflammation and sickness were produced by lipopolysaccharide (LPS, 0.1mg/kg, ip), while the 5-HT2A receptor was stimulated or blocked through the administration of the receptor agonist DOI or antagonist ketanserin (1mg/kg), respectively. LPS, DOI or ketanserin alone produced no effect on Tb. However, administration of LPS together with a peripheral or central ketanserin injection reduced Tb (32.2°C). Ketanserin reversed the LPS-induced expression of inducible NO synthase in the brain. Consequently, an involvement of NO in the mechanism of the hypothermic effect of ketanserin in sick mice was hypothesized. Administration of LPS together with NO synthase inhibitor, l-nitro-arginine methyl ester (60mg/kg, ip) resulted in deep (28.5°C) and prolonged (8h) hypothermia, while administration of l-nitro-arginine methyl ester alone produced no effect on Tb. Thus, 5-HT2A receptors play a key role in Tb control in sick mice. Blockade of this GPCR produces hypothermia in mice with systemic inflammation via attenuation of LPS-induced NO production. These results indicate an unexpected role of 5-HT2A receptors in inflammation and NO production and have a considerable biological impact on understanding the mechanism of animal adaptation to pathogens and parasites. Moreover, adverse side effects of 5-HT2A receptor antagonists in patients with inflammation may be expected. Copyright © 2015 Elsevier Ltd. All rights reserved.

Activity of Eribulin in Patients With Advanced Liposarcoma Demonstrated in a Subgroup Analysis From a Randomized Phase III Study of Eribulin Versus Dacarbazine.

PubMed

Demetri, George D; Schöffski, Patrick; Grignani, Giovanni; Blay, Jean-Yves; Maki, Robert G; Van Tine, Brian A; Alcindor, Thierry; Jones, Robin L; D'Adamo, David R; Guo, Matthew; Chawla, Sant

2017-10-20

Purpose A phase III study comparing eribulin with dacarbazine in patients with advanced liposarcoma (LPS) or leiomyosarcoma showed a significant improvement in overall survival (OS) for the eribulin arm, with a manageable toxicity profile. We now report the histology-specific subgroup analysis of the efficacy and safety of eribulin compared with dacarbazine in patients with LPS, an independently randomized stratified subgroup of this phase III trial. Methods Patients ≥ 18 years with advanced or metastatic dedifferentiated, myxoid/round cell, or pleomorphic LPS incurable by surgery or radiotherapy were included. Patients with Eastern Cooperative Oncology Group performance status ≤ 2 and two or more prior systemic treatment regimens, including one with anthracycline, were randomly assigned 1:1 to receive eribulin mesylate (1.4 mg/m 2 intravenously on days 1 and 8) or dacarbazine (850, 1,000, or 1,200 mg/m 2 intravenously on day 1) every 21 days. OS, progression-free survival (PFS), and safety were analyzed. Results In the LPS subgroup, OS was significantly improved: 15.6 versus 8.4 months (hazard ratio, 0.51; 95% CI, 0.35 to 0.75; P < .001) with eribulin versus dacarbazine, respectively. Longer OS with eribulin was observed in all LPS histologic subtypes and in all geographic regions evaluated. PFS was also improved with eribulin versus dacarbazine (2.9 v 1.7 months, respectively; hazard ratio, 0.52; 95% CI, 0.35 to 0.78; P = .0015). Adverse events were similar between arms. Conclusion In patients with previously treated LPS, eribulin was associated with significantly superior OS and PFS compared with dacarbazine. Eribulin represents an important treatment option for patients with LPS, a sarcoma subtype for which limited effective systemic treatments are available. Further studies are justified to explore the role of eribulin in earlier lines of therapy as well as in combination with other agents.

Super-resolution microscopy reveals protein spatial reorganization in early innate immune responses.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carson, Bryan D.; Aaron, Jesse S.; Timlin, Jerilyn Ann

2010-10-01

Over the past decade optical approaches were introduced that effectively break the diffraction barrier. Of particular note were introductions of Stimulated Emission/Depletion (STED) microscopy, Photo-Activated Localization Microscopy (PALM), and the closely related Stochastic Optical Reconstruction Microscopy (STORM). STORM represents an attractive method for researchers, as it does not require highly specialized optical setups, can be implemented using commercially available dyes, and is more easily amenable to multicolor imaging. We implemented a simultaneous dual-color, direct-STORM imaging system through the use of an objective-based TIRF microscope and filter-based image splitter. This system allows for excitation and detection of two fluorophors simultaneously, viamore » projection of each fluorophor's signal onto separate regions of a detector. We imaged the sub-resolution organization of the TLR4 receptor, a key mediator of innate immune response, after challenge with lipopolysaccharide (LPS), a bacteria-specific antigen. While distinct forms of LPS have evolved among various bacteria, only some LPS variations (such as that derived from E. coli) typically result in significant cellular immune response. Others (such as from the plague bacteria Y. pestis) do not, despite affinity to TLR4. We will show that challenge with LPS antigens produces a statistically significant increase in TLR4 receptor clusters on the cell membrane, presumably due to recruitment of receptors to lipid rafts. These changes, however, are only detectable below the diffraction limit and are not evident using conventional imaging methods. Furthermore, we will compare the spatiotemporal behavior of TLR4 receptors in response to different LPS chemotypes in order to elucidate possible routes by which pathogens such as Y. pestis are able to circumvent the innate immune system. Finally, we will exploit the dual-color STORM capabilities to simultaneously image LPS and TLR4 receptors in the cellular membrane at resolutions at or below 40nm.« less

Influence of a high-fat diet on gut microbiota, intestinal permeability and metabolic endotoxaemia.

PubMed

Moreira, Ana Paula Boroni; Texeira, Tatiana Fiche Salles; Ferreira, Alessandra Barbosa; Peluzio, Maria do Carmo Gouveia; Alfenas, Rita de Cássia Gonçalves

2012-09-01

Lipopolysaccharide (LPS) may play an important role in chronic diseases through the activation of inflammatory responses. The type of diet consumed is of major concern for the prevention and treatment of these diseases. Evidence from animal and human studies has shown that LPS can diffuse from the gut to the circulatory system in response to the intake of high amounts of fat. The method by which LPS move into the circulatory system is either through direct diffusion due to intestinal paracellular permeability or through absorption by enterocytes during chylomicron secretion. Considering the impact of metabolic diseases on public health and the association between these diseases and the levels of LPS in the circulatory system, this review will mainly discuss the current knowledge about high-fat diets and subclinical inflammation. It will also describe the new evidence that correlates gut microbiota, intestinal permeability and alkaline phosphatase activity with increased blood LPS levels and the biological effects of this increase, such as insulin resistance. Although the majority of the studies published so far have assessed the effects of dietary fat, additional studies are necessary to deepen the understanding of how the amount, the quality and the structure of the fat may affect endotoxaemia. The potential of food combinations to reduce the negative effects of fat intake should also be considered in future studies. In these studies, the effects of flavonoids, prebiotics and probiotics on endotoxaemia should be investigated. Thus, it is essential to identify dietetic strategies capable of minimising endotoxaemia and its postprandial inflammatory effects.

Chronic Ethanol Feeding Modulates Inflammatory Mediators, Activation of Nuclear Factor-κB, and Responsiveness to Endotoxin in Murine Kupffer Cells and Circulating Leukocytes

PubMed Central

Oppermann, Elsie; Jobin, Christian; Schleucher, Elke; Marzi, Ingo

2014-01-01

Chronic ethanol abuse is known to increase susceptibility to infections after injury, in part, by modification of macrophage function. Several intracellular signalling mechanisms are involved in the initiation of inflammatory responses, including the nuclear factor-κB (NF-κB) pathway. In this study, we investigated the systemic and hepatic effect of chronic ethanol feeding on in vivo activation of NF-κB in NF-κBEGFP reporter gene mice. Specifically, the study focused on Kupffer cell proinflammatory cytokines IL-6 and TNF-α and activation of NF-κB after chronic ethanol feeding followed by in vitro stimulation with lipopolysaccharide (LPS). We found that chronic ethanol upregulated NF-κB activation and increased hepatic and systemic proinflammatory cytokine levels. Similarly, LPS-stimulated IL-1β release from whole blood was significantly enhanced in ethanol-fed mice. However, LPS significantly increased IL-6 and TNF-α levels. These results demonstrate that chronic ethanol feeding can improve the responsiveness of macrophage LPS-stimulated IL-6 and TNF-α production and indicate that this effect may result from ethanol-induced alterations in intracellular signalling through NF-κB. Furthermore, LPS and TNF-α stimulated the gene expression of different inflammatory mediators, in part, in a NF-κB-dependent manner. PMID:24623963

Systemic administration of lipopolysaccharide increases the expression of aquaporin-4 in the rat anterior pituitary gland.

PubMed

Kuwahara-Otani, Sachi; Maeda, Seishi; Tanaka, Koichi; Hayakawa, Tetsu; Seki, Makoto

2013-01-01

We investigated the effects of lipopolysaccharide (LPS)-induced endotoxemia on the expression of aquaporin-4 (AQP4) in the rat anterior pituitary gland, using the real-time polymerase chain reaction and immunohistochemistry. After intraperitoneal injection of LPS, the level of AQP4 mRNA doubled at 2, 4 and 8 hr. Immunohistochemical analysis showed an increase with time in AQP4 immunostaining in folliculo-stellate cells following LPS injection; the intensity of immunoreactivity peaked at 8 hr. At the same time, some cyst-like structures, formed by AQP4-positive cells, were observed. These findings indicate that LPS induces the expression of AQP4 in the anterior pituitary gland. The present results should provide an important key to elucidate the pathogenesis of the anterior pituitary gland during endotoxemia.

CPEB1 modulates lipopolysaccharide-mediated iNOS induction in rat primary astrocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Ki Chan; Hyun Joo, So; Shin, Chan Young, E-mail: chanyshin@kku.ac.kr

2011-06-17

Highlights: {yields} Expression and phosphorylation of CPEB1 is increased by LPS stimulation in rat primary astrocytes. {yields} JNK regulates expression and phosphorylation of CPEB1 in reactive astrocytes. {yields} Down-regulation of CPEB1 using siRNA inhibits oxidative stress and iNOS induction by LPS stimulation. {yields} CPEB1 may play an important role in regulating inflammatory responses in reactive astrocytes induced by LPS. -- Abstract: Upon CNS damage, astrocytes undergo a series of biological changes including increased proliferation, production of inflammatory mediators and morphological changes, in a response collectively called reactive gliosis. This process is an essential part of the brains response to injury,more » yet much is unknown about the molecular mechanism(s) that induce these changes. In this study, we investigated the role of cytoplasmic polyadenylation element binding protein 1 (CPEB1) in the regulation of inflammatory responses in a model of reactive gliosis, lipopolysaccharide-stimulated astrocytes. CPEB1 is an mRNA-binding protein recently shown to be expressed in astrocytes that may play a role in astrocytes migration. After LPS stimulation, the expression and phosphorylation of CPEB1 was increased in rat primary astrocytes in a JNK-dependent process. siRNA-induced knockdown of CPEB1 expression inhibited the LPS-induced up-regulation of iNOS as well as NO and ROS production, a hallmark of immunological activation of astrocytes. The results from the study suggest that CPEB1 is actively involved in the regulation of inflammatory responses in astrocytes, which might provide new insights into the regulatory mechanism after brain injury.« less

The Transient Receptor Potential Vanilloid 1 Antagonist Capsazepine Improves the Impaired Lung Mechanics during Endotoxemia.

PubMed

Cabral, Layla D M; Giusti-Paiva, Alexandre

2016-11-01

Acute lung injury (ALI) caused by systemic inflammatory response remains a leading cause of morbidity and mortality in critically ill patients. Management of patients with sepsis is largely limited to supportive therapies, reflecting an incomplete understanding of the underlying pathophysiology. Furthermore, there have been limited advances in the treatments for ALI. In this study, lung function and a histological analysis were performed to evaluate the impact of transient receptor potential vanilloid-1 receptor (TRPV1) antagonist (capsazepine; CPZ) on the lipopolysaccharide (LPS)-induced lung injury in mice. For this, adult mice pre-treated with CPZ or vehicle received intraperitoneal injections of LPS or saline and 24 hr after, the mice were anaesthetized, and lung mechanics was evaluated. The LPS-challenged mice exhibited substantial mechanical impairment, characterized by increases in respiratory system resistance, respiratory system elastance, tissue damping and tissue elastance. The pre-treatment with CPZ prevented the increase in respiratory system resistance and decreased the increase in tissue damping during endotoxemia. In addition, mice pre-treated with CPZ had an attenuated lung injury evidenced by reduction on collapsed area of the lung parenchyma induced by LPS. This suggests that the TRPV1 antagonist capsazepine has a protective effect on lung mechanics in ALI during endotoxemia and that it may be a target for enhanced therapeutic efficacy in ALI. © 2016 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

B cell TLR1/2, TLR4, TLR7 and TLR9 interact in induction of class switch DNA recombination: modulation by BCR and CD40, and relevance to T-independent antibody responses.

PubMed

Pone, Egest J; Lou, Zheng; Lam, Tonika; Greenberg, Milton L; Wang, Rui; Xu, Zhenming; Casali, Paolo

2015-02-01

Ig class switch DNA recombination (CSR) in B cells is crucial to the maturation of antibody responses. It requires IgH germline IH-CH transcription and expression of AID, both of which are induced by engagement of CD40 or dual engagement of a Toll-like receptor (TLR) and B cell receptor (BCR). Here, we have addressed cross-regulation between two different TLRs or between a TLR and CD40 in CSR induction by using a B cell stimulation system involving lipopolysaccharides (LPS). LPS-mediated long-term primary class-switched antibody responses and memory-like antibody responses in vivo and induced generation of class-switched B cells and plasma cells in vitro. Consistent with the requirement for dual TLR and BCR engagement in CSR induction, LPS, which engages TLR4 through its lipid A moiety, triggered cytosolic Ca2+ flux in B cells through its BCR-engaging polysaccharidic moiety. In the presence of BCR crosslinking, LPS synergized with a TLR1/2 ligand (Pam3CSK4) in CSR induction, but much less efficiently with a TLR7 (R-848) or TLR9 (CpG) ligand. In the absence of BCR crosslinking, R-848 and CpG, which per se induced marginal CSR, virtually abrogated CSR to IgG1, IgG2a, IgG2b, IgG3 and/or IgA, as induced by LPS or CD154 (CD40 ligand) plus IL-4, IFN-γ or TGF-β, and reduced secretion of class-switched Igs, without affecting B cell proliferation or IgM expression. The CSR inhibition by TLR9 was associated with the reduction in AID expression and/or IgH germline IH-S-CH transcription, and required co-stimulation of B cells by CpG with LPS or CD154. Unexpectedly, B cells also failed to undergo CSR or plasma cell differentiation when co-stimulated by LPS and CD154. Overall, by addressing the interaction of TLR1/2, TLR4, TLR7 and TLR9 in the induction of CSR and modulation of TLR-dependent CSR by BCR and CD40, our study suggests the complexity of how different stimuli cross-regulate an important B cell differentiation process and an important role of TLRs in inducing effective T-independent antibody responses to microbial pathogens, allergens and vaccines.

B cell TLR1/2, TLR4, TLR7 and TLR9 interact in induction of class switch DNA recombination: modulation by BCR and CD40, and relevance to T-independent antibody responses

PubMed Central

Pone, Egest J.; Lou, Zheng; Lam, Tonika; Greenberg, Milton L.; Wang, Rui; Xu, Zhenming; Casali, Paolo

2015-01-01

Ig class switch DNA recombination (CSR) in B cells is crucial to the maturation of antibody responses. It requires IgH germline IH-CH transcription and expression of AID, both of which are induced by engagement of CD40 or dual engagement of a Toll-like receptor (TLR) and B cell receptor (BCR). Here, we have addressed cross-regulation between two different TLRs or between a TLR and CD40 in CSR induction by using a B cell stimulation system involving lipopolysaccharides (LPS). LPS mediated long-term primary class-switched antibody responses and memory-like antibody responses in vivo and induced generation of class-switched B cells and plasma cells in vitro. Consistent with the requirement for dual TLR and BCR engagement in CSR induction, LPS, which engages TLR4 through its lipid A moiety, triggered cytosolic Ca2+ flux in B cells through its BCR-engaging polysaccharidic moiety. In the presence of BCR crosslinking, LPS synergized with a TLR1/2 ligand (Pam3CSK4) in CSR induction, but much less efficiently with a TLR7 (R-848) or TLR9 (CpG) ligand. In the absence of BCR crosslinking, R-848 and CpG, which per se induced marginal CSR, virtually abrogated CSR to IgG1, IgG2a, IgG2b, IgG3 and/or IgA, as induced by LPS or CD154 (CD40 ligand) plus IL-4, IFN-γ or TGF-β, and reduced secretion of class-switched Igs, without affecting B cell proliferation or IgM expression. The CSR inhibition by TLR9 was associated with the reduction in AID expression and/or IgH germline IH-S-CH transcription, and required co-stimulation of B cells by CpG with LPS or CD154. Unexpectedly, B cells also failed to undergo CSR or plasma cell differentiation when co-stimulated by LPS and CD154. Overall, by addressing the interaction of TLR1/2, TLR4, TLR7 and TLR9 in the induction of CSR and modulation of TLR-dependent CSR by BCR and CD40, our study suggests the complexity of how different stimuli cross-regulate an important B cell differentiation process and an important role of TLRs in inducing effective T-independent antibody responses to microbial pathogens, allergens and vaccines. PMID:25536171

Elderly dendritic cells respond to LPS/IFN-γ and CD40L stimulation despite incomplete maturation

PubMed Central

Musk, Arthur W.; Alvarez, John; Mamotte, Cyril D. S.; Jackaman, Connie; Nowak, Anna K.; Nelson, Delia J.

2018-01-01

There is evidence that dendritic cells (DCs) undergo age-related changes that modulate their function with their key role being priming antigen-specific effector T cells. This occurs once DCs develop into antigen-presenting cells in response to stimuli/danger signals. However, the effects of aging on DC responses to bacterial lipopolysaccharide (LPS), the pro-inflammatory cytokine interferon (IFN)-γ and CD40 ligand (CD40L) have not yet been systematically evaluated. We examined responses of blood myeloid (m)DC1s, mDC2s, plasmacytoid (p)DCs, and monocyte-derived DCs (MoDCs) from young (21–40 years) and elderly (60–84 years) healthy human volunteers to LPS/IFN-γ or CD40L stimulation. All elderly DC subsets demonstrated comparable up-regulation of co-stimulatory molecules (CD40, CD80 and/or CD86), intracellular pro-inflammatory cytokine levels (IFN-γ, tumour necrosis factor (TNF)-α, IL-6 and/or IL-12), and/or secreted cytokine levels (IFN-α, IFN-γ, TNF-α, and IL-12) to their younger counterparts. Furthermore, elderly-derived LPS/IFN-γ or CD40L-activated MoDCs induced similar or increased levels of CD8+ and CD4+ T cell proliferation, and similar T cell functional phenotypes, to their younger counterparts. However, elderly LPS/IFN-γ-activated MoDCs were unreliable in their ability to up-regulate chemokine (IL-8 and monocyte chemoattractant protein (MCP)-1) and IL-6 secretion, implying an inability to dependably induce an inflammatory response. A key age-related difference was that, unlike young-derived MoDCs that completely lost their ability to process antigen, elderly-derived MoDCs maintained their antigen processing ability after LPS/IFN-γ maturation, measured using the DQ-ovalbumin assay; this response implies incomplete maturation that may enable elderly DCs to continuously present antigen. These differences may impact on the efficacy of anti-pathogen and anti-tumour immune responses in the elderly. PMID:29652910

Effects of binge-like ethanol exposure during adolescence on the hyperalgesia observed during sickness syndrome in rats.

PubMed

de Oliveira, Bruna M T; Telles, Tatiane M B B; Lomba, Luiz A; Correia, Diego; Zampronio, Aleksander R

2017-09-01

Acute and chronic ethanol exposure increases the risk of infection by altering the innate host's defense system. Adolescence is a critical period for brain development. Insults during this period may have long-lasting consequences. The present study investigated the effects of binge-like ethanol exposure in adolescent rats on mechanical hyperalgesia during sickness syndrome that was induced by a systemic injection of lipopolysaccharide (LPS) or an intracerebroventricular (i.c.v.) injection of interleukin-1β (IL-1β) after the cessation of ethanol exposure. Male Wistar rats were exposed to ethanol from postnatal day (PND) 25 to PND 38 in a binge-like pattern. Hyperalgesia was assessed on the right hindpaw after an intraperitoneal injection of LPS (5 and 50μg/kg, intraperitoneally) on PND 51 and PND 63 or an i.c.v. or intraplantar (i.pl.) injection of IL-β (3 and 1ng, respectively) on PND 51. Ethanol exposure during adolescence did not alter mechanical thresholds which increased normally with age. The systemic injection of LPS (0.5-50μg/kg) in adult rats induced dose-related mechanical hyperalgesia. Binge-like ethanol exposure significantly increased mechanical hyperalgesia that was induced by 50μg/kg LPS on PND 51 and 63, which lasted until 24h after the injection. This change was not observed at a lower dose of LPS (5μg/kg). Acute oral treatment with ethanol 24h prior to LPS administration did not alter mechanical hyperalgesia. The i.c.v. injection of IL-1β (1-10ng) also induced dose-related mechanical hyperalgesia in the right hindpaw in non-exposed animals. In animals that were exposed to binge-like ethanol, the i.c.v. or i.pl. injection of IL-1β also increased hyperalgesia on PND 51. These results suggest that binge-like ethanol exposure during adolescence causes alterations in the central nervous system that can increase mechanical hyperalgesia that is observed during sickness syndrome, and this effect can be observed until adulthood after the cessation of ethanol exposure. Copyright © 2017 Elsevier Inc. All rights reserved.

Fisetin Alleviates Lipopolysaccharide-Induced Acute Lung Injury via TLR4-Mediated NF-κB Signaling Pathway in Rats.

PubMed

Feng, Guang; Jiang, Ze-Yu; Sun, Bo; Fu, Jie; Li, Tian-Zuo

2016-02-01

Acute lung injury (ALI), a common component of systemic inflammatory disease, is a life-threatening condition without many effective treatments. Fisetin, a natural flavonoid from fruits and vegetables, was reported to have wide pharmacological properties such as anti-inflammatory, antioxidant, and anticancer activities. The aim of this study was to detect the effects of fisetin on lipopolysaccharide (LPS)-induced acute lung injury and investigate the potential mechanism. Fisetin was injected (1, 2, and 4 mg/kg, i.v.) 30 min before LPS administration (5 mg/kg, i.v.). Our results showed that fisetin effectively reduced the inflammatory cytokine release and total protein in bronchoalveolar lavage fluids (BALF), decreased the lung wet/dry ratios, and obviously improved the pulmonary histology in LPS-induced ALI. Furthermore, fisetin inhibited LPS-induced increases of neutrophils and macrophage infiltration and attenuated MPO activity in lung tissues. Additionally, fisetin could significantly inhibit the Toll-like receptor 4 (TLR4) expression and the activation of NF-κB in lung tissues. Our data indicates that fisetin has a protective effect against LPS-induced ALI via suppression of TLR4-mediated NF-κB signaling pathways, and fisetin may be a promising candidate for LPS-induced ALI treatment.

Decline and poleward shift in Indian summer monsoon synoptic activity in a warming climate.

PubMed

Sandeep, S; Ajayamohan, R S; Boos, William R; Sabin, T P; Praveen, V

2018-03-13

Cyclonic atmospheric vortices of varying intensity, collectively known as low-pressure systems (LPS), travel northwest across central India and produce more than half of the precipitation received by that fertile region and its ∼600 million inhabitants. Yet, future changes in LPS activity are poorly understood, due in part to inadequate representation of these storms in current climate models. Using a high-resolution atmospheric general circulation model that realistically simulates the genesis distribution of LPS, here we show that Indian monsoon LPS activity declines about 45% by the late 21st century in simulations of a business-as-usual emission scenario. The distribution of LPS genesis shifts poleward as it weakens, with oceanic genesis decreasing by ∼60% and continental genesis increasing by ∼10%; over land the increase in storm counts is accompanied by a shift toward lower storm wind speeds. The weakening and poleward shift of the genesis distribution in a warmer climate are confirmed and attributed, via a statistical model, to the reduction and poleward shift of low-level absolute vorticity over the monsoon region, which in turn are robust features of most coupled model projections. The poleward shift in LPS activity results in an increased frequency of extreme precipitation events over northern India. Copyright © 2018 the Author(s). Published by PNAS.

Decline and poleward shift in Indian summer monsoon synoptic activity in a warming climate

PubMed Central

Boos, William R.; Sabin, T. P.; Praveen, V.

2018-01-01

Cyclonic atmospheric vortices of varying intensity, collectively known as low-pressure systems (LPS), travel northwest across central India and produce more than half of the precipitation received by that fertile region and its ∼600 million inhabitants. Yet, future changes in LPS activity are poorly understood, due in part to inadequate representation of these storms in current climate models. Using a high-resolution atmospheric general circulation model that realistically simulates the genesis distribution of LPS, here we show that Indian monsoon LPS activity declines about 45% by the late 21st century in simulations of a business-as-usual emission scenario. The distribution of LPS genesis shifts poleward as it weakens, with oceanic genesis decreasing by ∼60% and continental genesis increasing by ∼10%; over land the increase in storm counts is accompanied by a shift toward lower storm wind speeds. The weakening and poleward shift of the genesis distribution in a warmer climate are confirmed and attributed, via a statistical model, to the reduction and poleward shift of low-level absolute vorticity over the monsoon region, which in turn are robust features of most coupled model projections. The poleward shift in LPS activity results in an increased frequency of extreme precipitation events over northern India. PMID:29483270

Decline and poleward shift in Indian summer monsoon synoptic activity in a warming climate

NASA Astrophysics Data System (ADS)

Sandeep, S.; Ajayamohan, R. S.; Boos, William R.; Sabin, T. P.; Praveen, V.

2018-03-01

Cyclonic atmospheric vortices of varying intensity, collectively known as low-pressure systems (LPS), travel northwest across central India and produce more than half of the precipitation received by that fertile region and its ˜600 million inhabitants. Yet, future changes in LPS activity are poorly understood, due in part to inadequate representation of these storms in current climate models. Using a high-resolution atmospheric general circulation model that realistically simulates the genesis distribution of LPS, here we show that Indian monsoon LPS activity declines about 45% by the late 21st century in simulations of a business-as-usual emission scenario. The distribution of LPS genesis shifts poleward as it weakens, with oceanic genesis decreasing by ˜60% and continental genesis increasing by ˜10%; over land the increase in storm counts is accompanied by a shift toward lower storm wind speeds. The weakening and poleward shift of the genesis distribution in a warmer climate are confirmed and attributed, via a statistical model, to the reduction and poleward shift of low-level absolute vorticity over the monsoon region, which in turn are robust features of most coupled model projections. The poleward shift in LPS activity results in an increased frequency of extreme precipitation events over northern India.

Oestrogen promotes healing in a bacterial LPS model of delayed cutaneous wound repair.

PubMed

Crompton, Rachel; Williams, Helen; Ansell, David; Campbell, Laura; Holden, Kirsty; Cruickshank, Sheena; Hardman, Matthew J

2016-04-01

Wound infection is a major clinical problem, yet understanding of bacterial host interactions in the skin remains limited. Microbe-derived molecules, known as pathogen-associated molecular patterns, are recognised in barrier tissues by pattern-recognition receptors. In particular, the pathogen-associated molecular pattern, lipopolysaccharide (LPS), a component of microbial cell walls and a specific ligand for Toll-like receptor 4, has been widely used to mimic systemic and local infection across a range of tissues. Here we administered LPS derived from Klebsiella pneumoniae, a species of bacteria that is emerging as a wound-associated pathogen, to full-thickness cutaneous wounds in C57/BL6 mice. Early in healing, LPS-treated wounds displayed increased local apoptosis and reduced proliferation. Subsequent healing progression was delayed with reduced re-epithelialisation, increased proliferation, a heightened inflammatory response and perturbed wound matrix deposition. Our group and others have previously demonstrated the beneficial effects of 17β-estradiol treatment across a range of preclinical wound models. Here we asked whether oestrogen would effectively promote healing in our LPS bacterial infection model. Intriguingly, co-treatment with 17β-estradiol was able to promote re-epithelialisation, dampen inflammation and induce collagen deposition in our LPS-delayed healing model. Collectively, these studies validate K. pneumoniae-derived LPS treatment as a simple yet effective model of bacterial wound infection, while providing the first indication that oestrogen could promote cutaneous healing in the presence of infection, further strengthening the case for its therapeutic use.

Effect of curcumin (Curcuma longa extract) on LPS-induced acute lung injury is mediated by the activation of AMPK.

PubMed

Kim, Joungmin; Jeong, Seong-Wook; Quan, Hui; Jeong, Cheol-Won; Choi, Jeong-Il; Bae, Hong-Beom

2016-02-01

Curcumin, a biphenolic compound extracted from turmeric (Curcuma longa), possesses potent anti-inflammatory activity. The present study investigated whether curcumin could increase 5' adenosine monophosphate-activated protein kinase (AMPK) activity in macrophages and modulate the severity of lipopolysaccharide (LPS)-induced acute lung injury. Macrophages were treated with curcumin and then exposed (or not) to LPS. Acute lung injury was induced by intratracheal administration of LPS in BALB/c mice. Curcumin increased phosphorylation of AMPK and acetyl-CoA carboxylase (ACC), a downstream target of AMPK, in a time- and concentration-dependent manner. Curcumin did not increase phosphorylation of liver kinase B1, a primary kinase upstream of AMPK. STO-609, an inhibitor of calcium(2+)/calmodulin-dependent protein kinase kinase, diminished curcumin-induced AMPK phosphorylation, but transforming growth factor-beta-activated kinase 1 inhibitor did not. Curcumin also diminished the LPS-induced increase in phosphorylation of inhibitory κB-alpha and the production of tumor necrosis factor alpha (TNF-α), macrophage inflammatory protein (MIP)-2, and interleukin (IL)-6 by macrophages. Systemic administration of curcumin significantly decreased the production of TNF-α, MIP-2, and IL-6 as well as neutrophil accumulation in bronchoalveolar lavage fluid, and also decreased pulmonary myeloperoxidase levels and the wet/dry weight ratio in mice subjected to LPS treatment. These results suggest that the protective effect of curcumin on LPS-induced acute lung injury is associated with AMPK activation.

An apple oligogalactan prevents against inflammation and carcinogenesis by targeting LPS/TLR4/NF-κB pathway in a mouse model of colitis-associated colon cancer.

PubMed

Liu, Li; Li, Yu H; Niu, Yin B; Sun, Yang; Guo, Zhen J; Li, Qian; Li, Chen; Feng, Juan; Cao, Shou S; Mei, Qi B

2010-10-01

Evidence strongly supported a link between inflammation and cancer. Patients with colitis have high risk for development of colon cancer. Nuclear factor-kappa B (NF-κB), partially induced by lipopolysaccharide (LPS) binding to Toll-like receptor (TLR) 4, is a vital molecule in supervising the transformation of colitis to colon cancer. It could be a good strategy to prevent colitis carcinogenesis for targeting LPS/TLR4/NF-κB pathway. In the present study, we obtained an oligogalactan composed of five galacturonic acids from apple pectin and evaluated its protective efficacy on intestinal toxicities and carcinogenesis in a mouse model of colitis-associated colon cancer induced by 1,2-dimethylhydrazine and dextran sodium sulfate (DSS). The apple oligogalactan (AOG) was highly effective against intestinal toxicities and carcinogenesis and decreased the elevated levels of TLR4 and tumor necrosis factor-α (TNF-α) induced by inflammation in vivo in this model system. In vitro studies, AOG alone only slightly increased the levels of protein expression and messenger RNA of TLR4, phosphorylation of IκBα and production of TNF-α in HT-29 cells. However, AOG significantly decreased the elevation of all the biomarkers induced by LPS when it was combined with LPS. The effect of AOG may be related to membrane internalization and redistribution of TLR4 from cell membrane to cytoplasm. AOG is active against inflammation and carcinogenesis through targeting LPS/TLR4/NF-κB pathway. Both AOG and LPS are agonists of TLR4 for sharing the same ligand but AOG has a much lower intrinsic activity than that of LPS. AOG may be useful for treatment of colitis and prevention of carcinogenesis in the clinics.

Exaggerated Increases in Microglia Proliferation, Brain Inflammatory Response and Sickness Behaviour upon Lipopolysaccharide Stimulation in Non-Obese Diabetic Mice.

PubMed

McGuiness, Barry; Gibney, Sinead M; Beumer, Wouter; Versnel, Marjan A; Sillaber, Inge; Harkin, Andrew; Drexhage, Hemmo A

2016-01-01

The non-obese diabetic (NOD) mouse, an established model for autoimmune diabetes, shows an exaggerated reaction of pancreas macrophages to inflammatory stimuli. NOD mice also display anxiety when immune-stimulated. Chronic mild brain inflammation and a pro-inflammatory microglial activation is critical in psychiatric behaviour. To explore brain/microglial activation and behaviour in NOD mice at steady state and after systemic lipopolysaccharide (LPS) injection. Affymetrix analysis on purified microglia of pre-diabetic NOD mice (8-10 weeks) and control mice (C57BL/6 and CD1 mice, the parental non-autoimmune strain) at steady state and after systemic LPS (100 μg/kg) administration. Quantitative PCR was performed on the hypothalamus for immune activation markers (IL-1β, IFNγ and TNFα) and growth factors (BDNF and PDGF). Behavioural profiling of NOD, CD1, BALB/c and C57BL/6 mice at steady state was conducted and sickness behaviour/anxiety in NOD and CD1 mice was monitored before and after LPS injection. Genome analysis revealed cell cycle/cell death and survival aberrancies of NOD microglia, substantiated as higher proliferation on BrdU staining. Inflammation signs were absent. NOD mice had a hyper-reactive response to novel environments with some signs of anxiety. LPS injection induced a higher expression of microglial activation markers, a higher brain pro-inflammatory set point (IFNγ, IDO) and a reduced expression of BDNF and PDGF after immune stimulation in NOD mice. NOD mice displayed exaggerated and prolonged sickness behaviour after LPS administration. After stimulation with LPS, NOD mice display an increased microglial proliferation and an exaggerated inflammatory brain response with reduced BDNF and PDGF expression and increased sickness behaviour as compared to controls. © 2016 S. Karger AG, Basel.

Combinatorial assembly of simple and complex D-lysergic acid alkaloid peptide classes in the ergot fungus Claviceps purpurea.

PubMed

Ortel, Ingo; Keller, Ullrich

2009-03-13

The ergot fungus Claviceps purpurea produces both ergopeptines and simple d-lysergic acid alkylamides. In the ergopeptines, such as ergotamine, d-lysergic acid is linked to a bicyclic tripeptide in amide-like fashion, whereas in the d-lysergylalkanolamides it is linked to an amino alcohol derived from alanine. We show here that these compound classes are synthesized by a set of three non-ribosomal lysergyl peptide synthetases (LPSs), which interact in a combinatorial fashion for synthesis of the relevant product. The trimodular LPS1 assembles with LPS2, the d-lysergic acid recruiting module, to synthesize the d-lysergyltripeptide precursors of ergopeptines from d-lysergic acid and the three amino acids of the peptide chain. Alternatively, LPS2 can assemble with a distinct monomodular non-ribosomal peptide synthetase (NRPS) subunit (ergometrine synthetase) to synthesize the d-lysergic acid alkanolamide ergometrine from d-lysergic acid and alanine. The synthesis proceeds via covalently bound d-lysergyl alanine and release of dipeptide as alcohol with consumption of NADPH. Enzymatic and immunochemical analyses showed that ergometrine synthetase is most probably the enzyme LPS3 whose gene had been identified previously as part of the ergot alkaloid biosynthesis gene cluster in C. purpurea. Inspections of all LPS sequences showed no recognizable peptide linkers for their protein-protein interactions as in NRPS subunits of bacteria. Instead, they all carry conserved N-terminal domains (C0-domains) with similarity to the C-terminal halves of NRPS condensation domains pointing to an alternative mechanism of subunit-subunit interactions in fungal NRPS systems. Phylogenetic analysis of LPS modules and the C0-domains suggests that these enzyme systems most probably evolved by module duplications and rearrangements from a bimodular ancestor.

Combinatorial Assembly of Simple and Complex d-Lysergic Acid Alkaloid Peptide Classes in the Ergot Fungus Claviceps purpurea*S⃞

PubMed Central

Ortel, Ingo; Keller, Ullrich

2009-01-01

The ergot fungus Claviceps purpurea produces both ergopeptines and simple d-lysergic acid alkylamides. In the ergopeptines, such as ergotamine, d-lysergic acid is linked to a bicyclic tripeptide in amide-like fashion, whereas in the d-lysergylalkanolamides it is linked to an amino alcohol derived from alanine. We show here that these compound classes are synthesized by a set of three non-ribosomal lysergyl peptide synthetases (LPSs), which interact in a combinatorial fashion for synthesis of the relevant product. The trimodular LPS1 assembles with LPS2, the d-lysergic acid recruiting module, to synthesize the d-lysergyltripeptide precursors of ergopeptines from d-lysergic acid and the three amino acids of the peptide chain. Alternatively, LPS2 can assemble with a distinct monomodular non-ribosomal peptide synthetase (NRPS) subunit (ergometrine synthetase) to synthesize the d-lysergic acid alkanolamide ergometrine from d-lysergic acid and alanine. The synthesis proceeds via covalently bound d-lysergyl alanine and release of dipeptide as alcohol with consumption of NADPH. Enzymatic and immunochemical analyses showed that ergometrine synthetase is most probably the enzyme LPS3 whose gene had been identified previously as part of the ergot alkaloid biosynthesis gene cluster in C. purpurea. Inspections of all LPS sequences showed no recognizable peptide linkers for their protein-protein interactions as in NRPS subunits of bacteria. Instead, they all carry conserved N-terminal domains (C0-domains) with similarity to the C-terminal halves of NRPS condensation domains pointing to an alternative mechanism of subunit-subunit interactions in fungal NRPS systems. Phylogenetic analysis of LPS modules and the C0-domains suggests that these enzyme systems most probably evolved by module duplications and rearrangements from a bimodular ancestor. PMID:19139103

Cytosolic NADP(+)-dependent isocitrate dehydrogenase protects macrophages from LPS-induced nitric oxide and reactive oxygen species.

PubMed

Maeng, Oky; Kim, Yong Chan; Shin, Han-Jae; Lee, Jie-Oh; Huh, Tae-Lin; Kang, Kwang-il; Kim, Young Sang; Paik, Sang-Gi; Lee, Hayyoung

2004-04-30

Macrophages activated by microbial lipopolysaccharides (LPS) produce bursts of nitric oxide and reactive oxygen species (ROS). Redox protection systems are essential for the survival of the macrophages since the nitric oxide and ROS can be toxic to them as well as to pathogens. Using suppression subtractive hybridization (SSH) we found that cytosolic NADP(+)-dependent isocitrate dehydrogenase (IDPc) is strongly upregulated by nitric oxide in macrophages. The levels of IDPc mRNA and of the corresponding enzymatic activity were markedly increased by treatment of RAW264.7 cells or peritoneal macrophages with LPS or SNAP (a nitric oxide donor). Over-expression of IDPc reduced intracellular peroxide levels and enhanced the survival of H2O2- and SNAP-treated RAW264.7 macrophages. IDPc is known to generate NADPH, a cellular reducing agent, via oxidative decarboxylation of isocitrate. The expression of enzymes implicated in redox protection, superoxide dismutase (SOD) and catalase, was relatively unaffected by LPS and SNAP. We propose that the induction of IDPc is one of the main self-protection mechanisms of macrophages against LPS-induced oxidative stress.

Teachers' Use of Learning Progression-Based Formative Assessment in Water Instruction

ERIC Educational Resources Information Center

Covitt, Beth A.; Gunckel, Kristin L.; Caplan, Bess; Syswerda, Sara

2018-01-01

While learning progressions (LPs) hold promise as instructional tools, researchers are still in the early stages of understanding how teachers use LPs in formative assessment practices. We report on a study that assessed teachers' proficiency in using a LP for student ideas about hydrologic systems. Research questions were: (a) what were teachers'…

Dimethylthiourea pretreatment inhibits endotoxin-induced compound exocytosis in goblet cells and plasma leakage of rat small intestine.

PubMed

Liu, Shang-Pin; Chang, Chien-Yu; Huang, Wen-Hung; Fu, Yaw-Syan; Chao, David; Huang, Hung-Tu

2010-01-01

Intravenous application of a high dose of endotoxin, also called lipopoly-saccharide (LPS), results in endotoxemia in animals, that induces production of cytokines and free radicals, systemic inflammation and mucin discharge from mucous tissues. The present study was to investigate (1) whether LPS application increased goblet cell secretion by compound exocytotic activity in mucosal villi and crypts of rat small intestine, and (2) whether hydroxyl radicals were involved in LPS-induced compound exocytosis in goblet cells and plasma leakage. Scanning electron microscopy showed that the numbers of goblet cells undergoing compound exocytosis (cavitated goblet cells) per mm(2) of ileal villus epithelium in rats 5 and 30 min after LPS (15 mg kg(-1)) were 693 +/- 196 (N = 6) and 547 +/- 213 (N = 6), respectively, which were 5.1 and 8.4 times (P < 0.05) the number of saline control. The percentage of villus cavitated goblet cell numbers, in both duodenum and ileum 5 min after LPS and in the ileum 30 min after LPS, increased significantly (P < 0.05). Pretreatment with dimethylthiourea (DMTU), a hydroxyl radical scavenger, decreased the number of cavitated goblet cells to saline control (P > 0.05). Morphometric analysis showed that the percentage of crypt epithelial area in the duodenum and ileum occupied by goblet cell mucin stores in the duodenum and ileum 30 min after LPS were 3.8 +/- 0.2% (N = 6) and 6.9 +/- 0.5 (N = 6), respectively reducing to one half the amount of control (P < 0.01). When DMTU was given prior to LPS the crypt goblet cell mucin stores and the amount of plasma leakage returned to the level of control. It is concluded that hydroxyl radicals were involved in the LPS-induced increase in compound exocytotic activity of goblet cells and the increase in plasma leakage during acute phases of inflammatory response in rat small intestine.

The regulation of cytochrome P450 2E1 during LPS-induced inflammation in the rat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdulla, Dalya; Goralski, Kerry B.; College of Pharmacy, Burbidge Building, Dalhousie University, Halifax, Nova Scotia, B3H 3J5

2006-10-01

It is well known that inflammatory and infectious conditions differentially regulate cytochrome P450 (P450)-mediated drug metabolism in the liver. We have previously outlined a potential pathway for the downregulation in hepatic cytochrome P450 following LPS-mediated inflammation in the CNS (Abdulla, D., Goralski, K.B., Garcia Del Busto Cano, E., Renton, K.W., 2005. The signal transduction pathways involved in hepatic cytochrome P450 regulation in the rat during an LPS-induced model of CNS inflammation. Drug Metab. Dispos). The purpose of this study was to outline the effects of LPS-induced peripheral and central nervous system inflammation on hepatic cytochrome P450 2E1 (CYP2E1) in vivo,more » an enzyme that plays an important role in various physiological and pathological states. We report an increase in hepatic mRNA expression of CYP2E1 that occurred as early as 2-3 h following either the intraperitoneal (i.p.) injection of 5 mg/kg LPS or i.c.v. administration of 25 {mu}g of LPS. This increase in CYP2E1 mRNA expression was sustained for 24 h. In sharp contrast to the increase in hepatic CYP2E1 mRNA, we observed a significant reduction in the catalytic activity of this enzyme 24 h following either the i.c.v. or i.p. administration of LPS. Cycloheximide or actinomycin-D did not change the LPS-mediated downregulation in hepatic CYP2E1 catalytic activity. Our results support the idea that LPS acts at two different levels to regulate hepatic CYP2E1: a transcriptional level to increase CYP2E1 mRNA expression and a post-transcriptional level to regulate CYP2E1 protein and activity.« less

Docosahexaenoic acid antagonizes the boosting effect of palmitic acid on LPS inflammatory signaling by inhibiting gene transcription and ceramide synthesis

PubMed Central

Jin, Junfei; Lu, Zhongyang; Li, Yanchun; Cowart, L. Ashley; Lopes-Virella, Maria F.

2018-01-01

It is well known that saturated fatty acids (SFAs) and unsaturated fatty acid, in particular omega-3 polyunsaturated fatty acids (n-3 PUFAs), have different effects on inflammatory signaling: SFAs are pro-inflammatory but n-3 PUFAs have strong anti-inflammatory properties. We have reported that palmitic acid (PA), a saturated fatty acid, robustly amplifies lipopolysaccharide (LPS) signaling to upregulate proinflammatory gene expression in macrophages. We also reported that the increased production of ceramide (CER) via sphingomyelin (SM) hydrolysis and CER de novo synthesis plays a key role in the synergistic effect of LPS and PA on proinflammatory gene expression. However, it remains unclear if n-3 PUFAs are capable of antagonizing the synergistic effect of LPS and PA on gene expression and CER production. In this study, we employed the above macrophage culture system and lipidomical analysis to assess the effect of n-3 PUFAs on proinflammatory gene expression and CER production stimulated by LPS and PA. Results showed that DHA strongly inhibited the synergistic effect of LPS and PA on proinflammatory gene expression by targeting nuclear factor kappa B (NFκB)-dependent gene transcription. Results also showed that DHA inhibited the cooperative effect of LPS and PA on CER production by targeting CER de novo synthesis, but not SM hydrolysis. Furthermore, results showed that myriocin, a specific inhibitor of serine palmitoyltransferase, strongly inhibited both LPS-PA-stimulated CER synthesis and proinflammatory gene expression, indicating that CER synthesis is associated with proinflammatory gene expression and that inhibition of CER synthesis contributes to DHA-inhibited proinflammatory gene expression. Taken together, this study demonstrates that DHA antagonizes the boosting effect of PA on LPS signaling on proinflammatory gene expression by targeting both NFκB-dependent transcription and CER de novo synthesis in macrophages. PMID:29474492

Docosahexaenoic acid antagonizes the boosting effect of palmitic acid on LPS inflammatory signaling by inhibiting gene transcription and ceramide synthesis.

PubMed

Jin, Junfei; Lu, Zhongyang; Li, Yanchun; Cowart, L Ashley; Lopes-Virella, Maria F; Huang, Yan

2018-01-01

It is well known that saturated fatty acids (SFAs) and unsaturated fatty acid, in particular omega-3 polyunsaturated fatty acids (n-3 PUFAs), have different effects on inflammatory signaling: SFAs are pro-inflammatory but n-3 PUFAs have strong anti-inflammatory properties. We have reported that palmitic acid (PA), a saturated fatty acid, robustly amplifies lipopolysaccharide (LPS) signaling to upregulate proinflammatory gene expression in macrophages. We also reported that the increased production of ceramide (CER) via sphingomyelin (SM) hydrolysis and CER de novo synthesis plays a key role in the synergistic effect of LPS and PA on proinflammatory gene expression. However, it remains unclear if n-3 PUFAs are capable of antagonizing the synergistic effect of LPS and PA on gene expression and CER production. In this study, we employed the above macrophage culture system and lipidomical analysis to assess the effect of n-3 PUFAs on proinflammatory gene expression and CER production stimulated by LPS and PA. Results showed that DHA strongly inhibited the synergistic effect of LPS and PA on proinflammatory gene expression by targeting nuclear factor kappa B (NFκB)-dependent gene transcription. Results also showed that DHA inhibited the cooperative effect of LPS and PA on CER production by targeting CER de novo synthesis, but not SM hydrolysis. Furthermore, results showed that myriocin, a specific inhibitor of serine palmitoyltransferase, strongly inhibited both LPS-PA-stimulated CER synthesis and proinflammatory gene expression, indicating that CER synthesis is associated with proinflammatory gene expression and that inhibition of CER synthesis contributes to DHA-inhibited proinflammatory gene expression. Taken together, this study demonstrates that DHA antagonizes the boosting effect of PA on LPS signaling on proinflammatory gene expression by targeting both NFκB-dependent transcription and CER de novo synthesis in macrophages.

Effects of different concentrations of isoflurane pretreatment on respiratory mechanics, oxygenation and hemodynamics in LPS-induced acute respiratory distress syndrome model of juvenile piglets.

PubMed

Fu, Haibin; Sun, Minli; Miao, Changhong

2015-01-01

This study was prospectively designed to investigate the effects of different concentrations of isoflurane (ISO) pretreatment on respiratory mechanics, oxygenation, and hemodynamics in lipopolysaccharide (LPS)-induced acute respiratory distress syndrome (ARDS) model of juvenile piglets. Twenty-four piglets (9-14 kg, 5-6 weeks old) were randomly assigned to four groups (n = 6): LPS group, which was injected with LPS (20 μg/kg) to induce ARDS; 0.5 ISO-LPS, 1.0 ISO-LPS, and 1.3 ISO-LPS groups, which were pretreated with 0.5, 1.0, and 1.3 minimum alveolar concentrations (MAC) ISO for 30 min before immediate LPS infusion, respectively. After establishment of ARDS, respiratory mechanism, oxygenation and hemodynamics parameters were measured at baseline, and 0, 1, 2, 3, and 4 hours after induction of ARDS. After induction of ARDS, there were increases in alveolar-arterial oxygen difference (A-aDO2), oxygenation index (OI), mean airway pressure (MAP), dead space-to-tidal volume ratio, heart rate (HR), dP/dtmax, extravascular lung water index, pulmonary vascular permeability index, and PaCO2, and decreases in PaO2/FIO2, respiratory rate (RR), dynamic lung compliance (Cdyn), mean arterial blood pressure (MABP) and systemic vascular resistance (SVR) compared with baseline (P(time) < 0.05). Pretreatment with 1.0 and 1.3 MAC ISO alleviated changes in dP/dtmax and PaCO2 at ARDS 0-2 hours, SVR at 0-3 hours, PaO2/FIO2, RR, and MABP at 1-2 hours, HR at 2-3 hours, A-aDO2 at 3-4 hours, and OI at 4 hours (P(group) < 0.05). Pretreatment with 1.0 and 1.3 MAC ISO had protective effects on respiratory mechanics, oxygenation, and hemodynamics in piglets with LPS-induced ARDS.

Melanization and Pathogenicity in the Insect, Tenebrio molitor, and the Crustacean, Pacifastacus leniusculus, by Aeromonas hydrophila AH-3

PubMed Central

Noonin, Chadanat; Jiravanichpaisal, Pikul; Söderhäll, Irene; Merino, Susana; Tomás, Juan M.; Söderhäll, Kenneth

2010-01-01

Aeromonas hydrophila is the most common Aeromonas species causing infections in human and other animals such as amphibians, reptiles, fish and crustaceans. Pathogenesis of Aeromonas species have been reported to be associated with virulence factors such as lipopolysaccharides (LPS), bacterial toxins, bacterial secretion systems, flagella, and other surface molecules. Several mutant strains of A. hydrophila AH-3 were initially used to study their virulence in two animal species, Pacifastacus leniusculus (crayfish) and Tenebrio molitor larvae (mealworm). The AH-3 strains used in this study have mutations in genes involving the synthesis of flagella, LPS structures, secretion systems, and some other factors, which have been reported to be involved in A. hydrophila pathogenicity. Our study shows that the LPS (O-antigen and external core) is the most determinant A. hydrophila AH-3 virulence factor in both animals. Furthermore, we studied the immune responses of these hosts to infection of virulent or non-virulent strains of A. hydrophila AH-3. The AH-3 wild type (WT) containing the complete LPS core is highly virulent and this bacterium strongly stimulated the prophenoloxidase activating system resulting in melanization in both crayfish and mealworm. In contrast, the ΔwaaE mutant which has LPS without O-antigen and external core was non-virulent and lost ability to stimulate this system and melanization in these two animals. The high phenoloxidase activity found in WT infected crayfish appears to result from a low expression of pacifastin, a prophenoloxidase activating enzyme inhibitor, and this gene expression was not changed in the ΔwaaE mutant infected animal and consequently phenoloxidase activity was not altered as compared to non-infected animals. Therefore we show that the virulence factors of A. hydrophila are the same regardless whether an insect or a crustacean is infected and the O-antigen and external core is essential for activation of the proPO system and as virulence factors for this bacterium. PMID:21206752

Lipopolysaccharide administration induces sex-dependent behavioural and serotonergic neurochemical signatures in mice.

PubMed

Sens, Jonathon; Schneider, Eric; Mauch, Joseph; Schaffstein, Anna; Mohamed, Sara; Fasoli, Kathryn; Saurine, Joseph; Britzolaki, Aikaterini; Thelen, Connor; Pitychoutis, Pothitos M

2017-02-01

Challenging the innate immune machinery with the pro-inflammatory agent lipopolysaccharide (LPS) results in the development of a sickness syndrome characterized by numerous depressive-like behavioural and physiological manifestations, most of which overlap with the clinical symptoms of major depression. Although women are known to mount stronger pro-inflammatory responses during infections and being at higher risk to develop depressive disorders compared to men, the vast majority of experimental studies investigating the neurobiological effects of LPS administration have been conducted in males. Herein, we investigated the behavioural effects of LPS administration (0.83mg/kg) in male and female C57BL/6J mice subjected to tests screening for alterations in locomotor activity (open field test), anorexia (food consumption), anhedonia (sucrose preference test), behavioural despair (forced swim test) and grooming behaviour (splash-test). We further mapped the brain's serotonergic and dopaminergic activity in five limbic brain regions implicated in the pathophysiology of major depression (i.e., prefrontal cortex, hippocampus, striatum, amygdala, and hypothalamus) at two critical time-points post-LPS treatment; at 6h when depression of behavioural activity is maximal, and at 24h when depressive-like symptoms develop independently of obvious locomotor performance impairments associated with acute LPS administration. Our findings indicate that the two sexes present with differential behavioural sensitivity to this immune stressor, as impairment of grooming behaviour in the splash test was more persistent in female mice, and anorexia lasted longer in their male counterparts. Notably, LPS affects the brain's serotonergic neurochemistry in a sex-specific manner, as it induced sustained serotonergic hyperactivity in females at 24h post-LPS administration in all the brain regions examined. Moreover, the kinetics of dopaminergic activation appeared to be sex-differentiated upon LPS challenge. Given the higher prevalence of affective disorders in women, a focus of basic science on sex differences that underlie neuroinflammatory processes is imperative in order to elucidate the neuroimmunological substrate of major depression. Copyright © 2017 Elsevier Inc. All rights reserved.

Anti-inflammatory effects of ursodeoxycholic acid by lipopolysaccharide-stimulated inflammatory responses in RAW 264.7 macrophages

PubMed Central

Ko, Wan-Kyu; Lee, Soo-Hong; Kim, Sung Jun; Jo, Min-Jae; Kumar, Hemant; Han, In-Bo; Sohn, Seil

2017-01-01

Purpose The aim of this study was to investigate the anti-inflammatory effects of Ursodeoxycholic acid (UDCA) in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Methods We induced an inflammatory process in RAW 264.7 macrophages using LPS. The anti-inflammatory effects of UDCA on LPS-stimulated RAW 264.7 macrophages were analyzed using nitric oxide (NO). Pro-inflammatory and anti-inflammatory cytokines were analyzed by quantitative real time polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA). The phosphorylations of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 in mitogen-activated protein kinase (MAPK) signaling pathways and nuclear factor kappa-light polypeptide gene enhancer in B-cells inhibitor, alpha (IκBα) signaling pathways were evaluated by western blot assays. Results UDCA decreased the LPS-stimulated release of the inflammatory mediator NO. UDCA also decreased the pro-inflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin 1-α (IL-1α), interleukin 1-β (IL-1β), and interleukin 6 (IL-6) in mRNA and protein levels. In addition, UDCA increased an anti-inflammatory cytokine interleukin 10 (IL-10) in the LPS-stimulated RAW 264.7 macrophages. UDCA inhibited the expression of inflammatory transcription factor nuclear factor kappa B (NF-κB) in LPS-stimulated RAW 264.7 macrophages. Furthermore, UDCA suppressed the phosphorylation of ERK, JNK, and p38 signals related to inflammatory pathways. In addition, the phosphorylation of IκBα, the inhibitor of NF-κB, also inhibited by UDCA. Conclusion UDCA inhibits the pro-inflammatory responses by LPS in RAW 264.7 macrophages. UDCA also suppresses the phosphorylation by LPS on ERK, JNK, and p38 in MAPKs and NF-κB pathway. These results suggest that UDCA can serve as a useful anti-inflammatory drug. PMID:28665991

A new metabolomic assay to examine inflammation and redox pathways following LPS challenge

PubMed Central

2012-01-01

Background Shifts in intracellular arginine (Arg) and sulfur amino acid (SAA) redox metabolism modulate macrophage activation, polarization and phenotype. Despite their importance in inflammation and redox regulatory pathways, comprehensive analysis of these metabolic networks was not previously possible with existing analytical methods. Methods The Arg/thiol redox LC-MS/MS metabolomics assay permits simultaneous assessment of amino acids and derivative products generated from Arg and SAA metabolism. Using this assay, LPS-induced changes in macrophage amino acid metabolism were monitored to identify pathway shifts during activation and their linkage to cellular redox regulation. Results Metabolite concentrations most significantly changed after treatment of a macrophage-like cell line (RAW) with LPS for 24 hrs were citrulline (Cit) (48-fold increase), ornithine (Orn) (8.5-fold increase), arginine (Arg) (66% decrease), and aspartic acid (Asp) (73% decrease). The ratio Cit + Orn/Arg + Asp (CO/AA) was more sensitive to LPS stimulation than other amino acid ratios commonly used to measure LPS-dependent inflammation (e.g., SAM/SAH, GSH/GSSG) and total media NOx. The CO/AA ratio was also the first ratio to change significantly after LPS treatment (4 hrs). Changes in the overall metabolomic profile over time indicated that metabolic pathways shifted from Arg catabolism to thiol oxidation. Conclusions Simultaneous quantification of Arg and SAA metabolic pathway shifts following LPS challenge of macrophage indicate that, in this system, the Arg-Citrulline/NO cycle and arginase pathways are the amino acid metabolic pathways most sensitive to LPS-challenge. The cellular (Cit + Orn)/(Arg + Asp) ratio, which summarizes this pathway, was more responsive to lower concentrations of LPS and responded earlier than other metabolic biomarkers of macrophage activation including GSH redox. It is suggested that the CO/AA ratio is a redox- independent early biomarker of macrophage activation. The ability to measure both the CO/AA and GSH-redox ratios simultaneously permits quantification of the relative effects of LPS challenge on macrophage inflammation and oxidative stress pathways. The use of this assay in humans is discussed, as are clinical implications. PMID:23036094

L-Ascorbate Attenuates the Endotoxin-Induced Production of Inflammatory Mediators by Inhibiting MAPK Activation and NF-κB Translocation in Cortical Neurons/Glia Cocultures

PubMed Central

Huang, Ya-Ni; Lai, Chien-Cheng; Chiu, Chien-Tsai; Lin, Jhen-Jhe; Wang, Jia-Yi

2014-01-01

In response to acute insults to the central nervous system, such as pathogen invasion or neuronal injuries, glial cells become activated and secrete inflammatory mediators such as nitric oxide (NO), cytokines, and chemokines. This neuroinflammation plays a crucial role in the pathophysiology of chronic neurodegenerative diseases. Endogenous ascorbate levels are significantly decreased among patients with septic encephalopathy. Using the bacterial endotoxin lipopolysaccharide (LPS) to induce neuroinflammation in primary neuron/glia cocultures, we investigated how L-ascorbate (vitamin C; Vit. C) affected neuroinflammation. LPS (100 ng/ml) induced the expression of inducible NO synthase (iNOS) and the production of NO, interleukin (IL)-6, and macrophage inflammatory protein-2 (MIP-2/CXCL2) in a time-dependent manner; however, cotreatment with Vit. C (5 or 10 mM) attenuated the LPS-induced iNOS expression and production of NO, IL-6, and MIP-2 production. The morphological features revealed after immunocytochemical staining confirmed that Vit. C suppressed LPS-induced astrocytic and microglial activation. Because Vit. C can be transported into neurons and glia via the sodium-dependent Vit. C transporter-2, we examined how Vit. C affected LPS-activated intracellular signaling in neuron/glia cocultures. The results indicated the increased activation (caused by phosphorylation) of mitogen-activated protein kinases (MAPKs), such as p38 at 30 min and extracellular signal-regulated kinases (ERKs) at 180 min after LPS treatment. The inhibition of p38 and ERK MAPK suppressed the LPS-induced production of inflammatory mediators. Vit. C also inhibited the LPS-induced activation of p38 and ERK. Combined treatments of Vit. C and the inhibitors of p38 and ERK yielded no additional inhibition compared with using the inhibitors alone, suggesting that Vit. C functions through the same signaling pathway (i.e., MAPK) as these inhibitors. Vit. C also reduced LPS-induced IκB-α degradation and NF-κB translocation. Thus, Vit. C suppressed the LPS-stimulated production of inflammatory mediators in neuron/glia cocultures by inhibiting the MAPK and NF-κB signaling pathways. PMID:24983461

Impact of Helicobacter pylori on the healing process of the gastric barrier

PubMed Central

Mnich, Eliza; Kowalewicz-Kulbat, Magdalena; Sicińska, Paulina; Hinc, Krzysztof; Obuchowski, Michał; Gajewski, Adrian; Moran, Anthony P; Chmiela, Magdalena

2016-01-01

AIM To determine the impact of selected well defined Helicobacter pylori (H. pylori) antigens on gastric barrier cell turnover. METHODS In this study, using two cellular models of gastric epithelial cells and fibroblasts, we have focused on exploring the effects of well defined H. pylori soluble components such as glycine acid extract antigenic complex (GE), subunit A of urease (UreA), cytotoxin associated gene A protein (CagA) and lipopolysaccharide (LPS) on cell turnover by comparing the wound healing capacity of the cells in terms of their proliferative and metabolic activity as well as cell cycle distribution. Toxic effects of H. pylori components have been assessed in an association with damage to cell nuclei and inhibition of signal transducer and activator of transcription 3 (STAT3) phosphorylation. RESULTS We showed that H. pylori GE, CagA and UreA promoted regeneration of epithelial cells and fibroblasts, which is necessary for effective tissue healing. However, in vivo increased proliferative activity of these cells may constitute an increased risk of gastric neoplasia. In contrast, H. pylori LPS showed a dose-dependent influence on the process of wound healing. At a low concentration (1 ng/mL) H. pylori LPS accelerated of healing epithelial cells, which was linked to significantly enhanced cell proliferation and MTT reduction as well as lack of alterations in cell cycle and downregulation of epidermal growth factor (EGF) production as well as cell nuclei destruction. By comparison, H. pylori LPS at a high concentration (25 ng/mL) inhibited the process of wound repair, which was related to diminished proliferative activity of the cells, cell cycle arrest, destruction of cell nuclei and downregulation of the EGF/STAT3 signalling pathway. CONCLUSION In vivo H. pylori LPS driven effects might lead to the maintenance of chronic inflammatory response and pathological disorders on the level of the gastric mucosal barrier. PMID:27672275

Effects of protease activated receptor (PAR)2 blocking peptide on endothelin-1 levels in kidney tissues in endotoxemic rat mode.

PubMed

Jesmin, Subrina; Shimojo, Nobutake; Yamaguchi, Naoto; Mowa, Chishimba Nathan; Oki, Masami; Zaedi, Sohel; Sultana, Sayeeda Nusrat; Rahman, Arifur; Islam, Majedul; Sawamura, Atsushi; Gando, Satoshi; Kawano, Satoru; Miyauchi, Takashi; Mizutani, Taro

2014-05-02

Septic shock, the severe form of sepsis, is associated with development of progressive damage in multiple organs. Kidney can be injured and its functions altered by activation of coagulation, vasoactive-peptide and inflammatory processes in sepsis. Endothelin (ET)-1, a potent vasoconstrictor, is implicated in the pathogenesis of sepsis and its complications. Protease-activated receptors (PARs) are shown to play an important role in the interplay between inflammation and coagulation. We examined the time-dependent alterations of ET-1 and inflammatory cytokine, such as tumor necrosis factor (TNF)-α in kidney tissue in lipopolysaccharide (LPS)-induced septic rat model and the effects of PAR2 blocking peptide on the LPS-induced elevations of renal ET-1 and TNF-α levels. Male Wistar rats at 8 weeks of age were administered with either saline solution or LPS at different time points (1, 3, 6 and 10h). Additionally, we treated LPS-administered rats with PAR2 blocking peptide for 3h to assess whether blockade of PAR2 has a regulatory role on the ET-1 level in septic kidney. An increase in ET-1 peptide level was observed in kidney tissue after LPS administration time-dependently. Levels of renal TNF-α peaked (around 12-fold) at 1h of sepsis. Interestingly, PAR2 blocking peptide normalized the LPS-induced elevations of renal ET-1 and TNF-α levels. The present study reveals a distinct chronological expression of ET-1 and TNF-α in LPS-administered renal tissues and that blockade of PAR2 may play a crucial role in treating renal injury, via normalization of inflammation, coagulation and vaso-active peptide. Copyright © 2014 Elsevier Inc. All rights reserved.

Effects of β-Glucan on the Release of Nitric Oxide by Macrophages Stimulated with Lipopolysaccharide

PubMed Central

Choi, E. Y.; Lee, S. S.; Hyeon, J. Y.; Choe, S. H.; Keum, B. R.; Lim, J. M.; Park, D. C.; Choi, I. S.; Cho, K. K.

2016-01-01

This research analyzed the effect of β-glucan that is expected to alleviate the production of the inflammatory mediator in macrophagocytes, which are processed by the lipopolysaccharide (LPS) of Escherichia. The incubated layer was used for a nitric oxide (NO) analysis. The DNA-binding activation of the small unit of nuclear factor-κB was measured using the enzyme-linked immunosorbent assay-based kit. In the RAW264.7 cells that were vitalized by Escherichia coli (E. coli) LPS, the β-glucan inhibited both the combatant and rendering phases of the inducible NO synthase (iNOS)-derived NO. β-Glucan increased the expression of the heme oxygenase-1 (HO-1) in the cells that were stimulated by E. coli LPS, and the HO-1 activation was inhibited by the tin protoporphyrin IX (SnPP). This shows that the NO production induced by LPS is related to the inhibition effect of β-glucan. The phosphorylation of c-Jun N-terminal kinases (JNK) and the p38 induced by the LPS were not influenced by the β-glucan, and the inhibitory κB-α (IκB-α) decomposition was not influenced either. Instead, β-glucan remarkably inhibited the phosphorylation of the signal transducer and activator of transcription-1 (STAT1) that was induced by the E. coli LPS. Overall, the β-glucan inhibited the production of NO in macrophagocytes that was vitalized by the E .coli LPS through the HO-1 induction and the STAT1 pathways inhibition in this research. As the host immune response control by β-glucan weakens the progress of the inflammatory disease, β-glucan can be used as an effective immunomodulator. PMID:27488844

IL-1β directly suppress ghrelin mRNA expression in ghrelin-producing cells.

PubMed

Bando, Mika; Iwakura, Hiroshi; Ueda, Yoko; Ariyasu, Hiroyuki; Inaba, Hidefumi; Furukawa, Yasushi; Furuta, Hiroto; Nishi, Masahiro; Akamizu, Takashi

2017-05-15

In animal models, ghrelin production is suppressed by LPS administration. To elucidate the detailed molecular mechanisms involved in the phenomenon, we investigated the effects of LPS and LPS-inducible cytokines, including TNF-α, IL-1β, and IL-6, on the expression of ghrelin in the ghrelin-producing cell line MGN3-1. These cells expressed IL-1R, and IL-1β significantly suppressed ghrelin mRNA levels. The suppressive effects of IL-1β were attenuated by knockdown of IKKβ, suggesting the involvement of the NF-κB pathway. These results suggested that IL-1β is a major regulator of ghrelin expression during inflammatory processes. Copyright © 2017 Elsevier B.V. All rights reserved.

Post-ruminal branched-chain amino acid supplementation and intravenous lipopolysaccharide infusion alters blood metabolites, rumen fermentation, and nitrogen balance of beef steers.

PubMed

Löest, C A; Gilliam, G G; Waggoner, J W; Turner, J L

2018-04-27

Steers exposed to an endotoxin may require additional branched-chain AA (BCAA) to support an increase in synthesis of immune proteins. This study evaluated effects of bacterial lipopolysaccharide (LPS) and BCAA supplementation on blood metabolites and N balance of 20 ruminally-cannulated steers (177 ± 4.2 kg BW). The experiment was a randomized block design, with 14-d adaptation to metabolism stalls and diet (DM fed = 1.5% BW) and 6-d collection. Treatments were a 2 × 2 factorial of LPS (0 vs 1.0 to 1.5 μg/kg BW; -LPS vs +LPS) and BCAA (0 vs 35 g/d; -BCAA vs +BCAA). The LPS in 100 mL sterile saline was infused (1 mL/min via i.v. catheter) on d 15. The BCAA in an essential AA solution were abomasally infused (900 mL/d) 3 times daily in equal portions beginning on d 7. Blood, rumen fluid, and rectal temperature were collected on d 15 at h 0, 2, 4, 8, 12, and 24 after LPS infusion. Feces and urine were collected from d 16 to 20. Rectal temperatures were greater for +LPS vs. -LPS steers at 4 h and lower at 8 h after LPS infusion (LPS h, P < 0.01). Serum cortisol and plasma urea N were greater for +LPS than -LPS steers at 2 (cortisol only), 4, 8, 12, and 24 h after LPS infusion (LPS × h, P < 0.01). Serum cortisol was greater for +BCAA than -BCAA steers at 12 h after LPS infusion (BCAA × h, P < 0.05). Serum glucose was greater for +LPS than -LPS steers at 2 h after LPS infusion (LPS × h, P < 0.01). Plasma Ile, Leu, and Val were lower, and plasma His was greater in +LPS than -LPS steers (LPS, P < 0.05). Plasma Lys, Met, Thr, and Trp of +LPS steers was lower than -LPS steers at 4 (Thr only), 8 (Lys and Trp only), 12, and 24 h after infusion (LPS × h, P < 0.05). Plasma Ile, Leu, and Val were greater (BCAA, P < 0.01), and Met, His, Phe, Thr, and Trp were lower for +BCAA than -BCAA steers at 0 h and 24 h after LPS infusion (BCAA × h, P ≤ 0.05). Steers receiving +LPS had lower rumen pH at 8 h, greater total VFA at 8 h, and lower rumen NH3 at 24 h after LPS infusion compared with -LPS steers (LPS × h, P ≤ 0.04). Total tract passage rates, DM, OM, NDF, ADF, and N intake, fecal N, digested N, and retained N were lower (P < 0.05) for +LPS than -LPS steers. Total N supply (dietary plus infused) and fecal N were greater (P < 0.05) for +BCAA vs -BCAA steers. The absence of LPS × BCAA interactions (P ≥ 0.20) for N balance indicated that post-ruminal supplementation of BCAA did not alleviate the negative effects of endotoxin on N utilization by growing steers.

Disaggregation of lipopolysaccharide by albumin, hemoglobin or high-density lipoprotein, forming complexes that prime neutrophils for enhanced release of superoxide.

PubMed

Komatsu, Toshiya; Aida, Yoshitomi; Fukuda, Takao; Sanui, Terukazu; Hiratsuka, Shunji; Pabst, Michael J; Nishimura, Fusanori

2016-04-01

We studied the interaction of LPS with albumin, hemoglobin or high-density lipoprotein (HDL), and whether the interaction affected the activity of LPS on neutrophils. These proteins disaggregated LPS, depending upon temperature and LPS:protein ratio. Albumin-treated LPS was absorbed by immobilized anti-albumin antibody and was eluted with Triton X-100, indicating that LPS formed a hydrophobic complex with albumin. Rd mutant LPS was not disaggregated by the proteins, and did not form a complex with the proteins. But triethylamine-treated Rd mutant LPS formed complexes. When LPS was incubated with an equal concentration of albumin and with polymyxin B (PMXB), PMXB-LPS-protein three-way complexes were formed. After removal of PMXB, the complexes consisted of 11-15 LPS monomers bound to one albumin or hemoglobin molecule. LPS primed neutrophils for enhanced release of formyl peptide-stimulated superoxide, in a serum- and LPS-binding protein (LBP)-dependent manner. Although LPS plus LBP alone did not prime neutrophils, albumin-, hemoglobin- or HDL-treated LPS primed neutrophils when added with LBP. Triethylamine-treated Rd mutant LPS primed neutrophils only when incubated with one of the proteins and with LBP. Thus, in addition to LBP, disaggregation and complex formation of LPS with one of these proteins is required for LPS to prime neutrophils. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Involvement of interleukin-23 induced by Porphyromonas endodontalis lipopolysaccharide in osteoclastogenesis

PubMed Central

Ma, Nan; Yang, Di; Okamura, Hirohiko; Teramachi, Jumpei; Hasegawa, Tomokazu; Qiu, Lihong; Haneji, Tatsuji

2017-01-01

Periapical lesions are characterized by the destruction of periapical bone, and occur as a result of local inflammatory responses to root canal infection by microorganisms including Porphyromonas endodontalis (P. endodontalis). P. endodontalis and its primary virulence factor, lipopolysaccharide (LPS), are associated with the development of periapical lesions and alveolar bone loss. Interleukin-23 (IL-23) is critical in the initiation and progression of periodontal disease via effects on peripheral bone metabolism. The present study investigated the expression of IL-23 in tissue where a periapical lesion was present, and the effect of P. endodontalis LPS on the expression of IL-23 in periodontal ligament (PDL) cells. Reverse transcription- quantitative polymerase chain reaction and immunohistochemistry revealed increased levels of IL-23 expression in tissue with periapical lesions compared with healthy PDL tissue. Treatment with P. endodontalis LPS increased the expression of IL-23 in the SH-9 human PDL cell line. BAY11-7082, a nuclear factor κB inhibitor, suppressed P. endodontalis LPS-induced IL-23 expression in SH-9 cells. Treatment of RAW264.7 cells with conditioned medium from P. endodontalis LPS-treated SH-9 cells promoted osteoclastogenesis. By contrast, RAW264.7 cells treated with conditioned medium from IL-23-knockdown SH-9 cells underwent reduced levels of osteoclastogenesis. The results of the present study indicated that the expression of IL-23 in PDL cells induced by P. endodontalis LPS treatment may be involved in the progression of periapical lesions via stimulation of the osteoclastogenesis process. PMID:28000855

Anacardic acid, a histone acetyltransferase inhibitor, modulates LPS-induced IL-8 expression in a human alveolar epithelial cell line A549

PubMed Central

Takizawa, Hajime

2013-01-01

Objective and design: The histone acetylation processes, which are believed to play a critical role in the regulation of many inflammatory genes, are reversible and regulated by histone acetyltransferases (HATs), which promote acetylation, and histone deacetylases (HDACs), which promote deacetylation. We studied the effects of lipopolysaccharide (LPS) on histone acetylation and its role in the regulation of interleukin (IL)-8 expression.  Material: A human alveolar epithelial cell line A549 was used in vitro. Methods: Histone H4 acetylation at the IL-8 promoter region was assessed by a chromatin immunoprecipitation (ChIP) assay. The expression and production of IL-8 were evaluated by quantitative polymerase chain reaction and specific immunoassay. Effects of a HDAC inhibitor, trichostatin A (TSA), and a HAT inhibitor, anacardic acid, were assessed.  Results: Escherichia coli-derived LPS showed a dose- and time-dependent stimulatory effect on IL-8 protein production and mRNA expression in A549 cells in vitro. LPS showed a significant stimulatory effect on histone H4 acetylation at the IL-8 promoter region by ChIP assay. Pretreatment with TSA showed a dose-dependent stimulatory effect on IL-8 release from A549 cells as compared to LPS alone. Conversely, pretreatment with anacardic acid inhibited IL-8 production and expression in A549 cells.  Conclusion: These data suggest that LPS-mediated proinflammatory responses in the lungs might be modulated via changing chromatin remodeling by HAT inhibition. PMID:24627774

Lipopolysaccharide-induced dopaminergic cell death in rat midbrain slice cultures: role of inducible nitric oxide synthase and protection by indomethacin.

PubMed

Shibata, Haruki; Katsuki, Hiroshi; Nishiwaki, Mayumi; Kume, Toshiaki; Kaneko, Shuji; Akaike, Akinori

2003-09-01

Glial cell activation associated with inflammatory reaction may contribute to pathogenic processes of neurodegenerative disorders, through production of several cytotoxic molecules. We investigated the consequences of glial activation by interferon-gamma (IFN-gamma)/lipopolysaccharide (LPS) in rat midbrain slice cultures. Application of IFN-gamma followed by LPS caused dopaminergic cell death and accompanying increases in nitrite production and lactate dehydrogenase release. Aminoguanidine, an inhibitor of inducible nitric oxide synthase (iNOS), or SB203580, an inhibitor of p38 mitogen-activated protein kinase, prevented dopaminergic cell loss as well as nitrite production. SB203580 also suppressed expression of iNOS and cyclooxygenase-2 (COX-2) induced by IFN-gamma/LPS. A COX inhibitor indomethacin protected dopaminergic neurons from IFN-gamma/LPS-induced injury, whereas selective COX-2 inhibitors such as NS-398 and nimesulide did not. Notably, indomethacin was able to attenuate neurotoxicity of a nitric oxide (NO) donor. Neutralizing antibodies against tumour necrosis factor-alpha and interleukin-1beta did not inhibit dopaminergic cell death caused by IFN-gamma/LPS, although combined application of these antibodies blocked lactate dehydrogenase release and decrease in the number of non-dopaminergic neurons. These results indicate that iNOS-derived NO plays a crucial role in IFN-gamma/LPS-induced dopaminergic cell death, and that indomethacin exerts protective effect by mechanisms probably related to NO neurotoxicity rather than through COX inhibition.

Activation of the NLRP3 inflammasome in lipopolysaccharide-induced mouse fatigue and its relevance to chronic fatigue syndrome.

PubMed

Zhang, Zi-Teng; Du, Xiu-Ming; Ma, Xiu-Juan; Zong, Ying; Chen, Ji-Kuai; Yu, Chen-Lin; Liu, Yan-Gang; Chen, Yong-Chun; Zhao, Li-Jun; Lu, Guo-Cai

2016-04-05

The NLRP3 inflammasome (NOD-like receptor family, pyrin domain containing 3) is an intracellular protein complex that plays an important role in innate immune sensing. Its activation leads to the maturation of caspase-1 and regulates the cleavage of interleukin (IL)-1β and IL-18. Various studies have shown that activation of the immune system plays a pivotal role in the development of fatigue. However, the mechanisms underlying the association between immune activation and fatigue remained elusive, and few reports have described the involvement of NLRP3 inflammasome activation in fatigue. We established a mouse fatigue model with lipopolysaccharide (LPS, 3 mg/kg) challenge combined with swim stress. Both behavioural and biochemical parameters were measured to illustrate the characteristics of this model. We also assessed NLRP3 inflammasome activation in the mouse diencephalon, which is the brain region that has been suggested to be responsible for fatigue sensation. To further identify the role of NLRP3 inflammasome activation in the pathogenesis of chronic fatigue syndrome (CFS), NLRP3 KO mice were also subjected to LPS treatment and swim stress, and the same parameters were evaluated. Mice challenged with LPS and subjected to the swim stress test showed decreased locomotor activity, decreased fall-off time in a rota-rod test and increased serum levels of IL-1β and IL-6 compared with untreated mice. Serum levels of lactic acid and malondialdehyde (MDA) were not significantly altered in the treated mice. We demonstrated increased NLRP3 expression, IL-1β production and caspase-1 activation in the diencephalons of the treated mice. In NLRP3 KO mice, we found remarkably increased locomotor activity with longer fall-off times and decreased serum IL-1β levels compared with those of wild-type (WT) mice after LPS challenge and the swim stress test. IL-1β levels in the diencephalon were also significantly decreased in the NLRP3 KO mice. By contrast, IL-6 levels were not significantly altered. These findings suggest that LPS-induced fatigue is an IL-1β-dependent process and that the NLRP3/caspase-1 pathway is involved in the mechanisms of LPS-induced fatigue behaviours. NLRP3/caspase-1 inhibition may be a promising therapy for fatigue treatment.

Polymethoxy flavonoids, nobiletin and tangeretin, prevent lipopolysaccharide-induced inflammatory bone loss in an experimental model for periodontitis.

PubMed

Tominari, Tsukasa; Hirata, Michiko; Matsumoto, Chiho; Inada, Masaki; Miyaura, Chisato

2012-01-01

Nobiletin, a polymethoxy flavonoid (PMF), inhibits systemic bone resorption and maintains bone mass in estrogen-deficient ovariectomized mice. This study examined the anti-inflammatory effects of PMFs, nobiletin, and tangeretin on lipopolysaccharide (LPS)-induced bone resorption. Nobiletin and tangeretin suppressed LPS-induced osteoclast formation and bone resorption and suppressed the receptor activator of NFκB ligand-induced osteoclastogenesis in RAW264.7 macrophages. Nobiletin clearly restored the alveolar bone mass in a mouse experimental model for periodontitis by inhibiting LPS-induced bone resorption. PMFs may therefore provide a new therapeutic approach for periodontal bone loss.

Flow of a Gas Turbine Engine Low-Pressure Subsystem Simulated

NASA Technical Reports Server (NTRS)

Veres, Joseph P.

1997-01-01

The NASA Lewis Research Center is managing a task to numerically simulate overnight, on a parallel computing testbed, the aerodynamic flow in the complete low-pressure subsystem (LPS) of a gas turbine engine. The model solves the three-dimensional Navier- Stokes flow equations through all the components within the LPS, as well as the external flow around the engine nacelle. The LPS modeling task is being performed by Allison Engine Company under the Small Engine Technology contract. The large computer simulation was evaluated on networked computer systems using 8, 16, and 32 processors, with the parallel computing efficiency reaching 75 percent when 16 processors were used.

Genetic Characterization of a Sinorhizobium meliloti Chromosomal Region Involved in Lipopolysaccharide Biosynthesis

PubMed Central

Lagares, Antonio; Hozbor, Daniela F.; Niehaus, Karsten; Otero, Augusto J. L. Pich; Lorenzen, Jens; Arnold, Walter; Pühler, Alfred

2001-01-01

The genetic characterization of a 5.5-kb chromosomal region of Sinorhizobium meliloti 2011 that contains lpsB, a gene required for the normal development of symbiosis with Medicago spp., is presented. The nucleotide sequence of this DNA fragment revealed the presence of six genes: greA and lpsB, transcribed in the forward direction; and lpsE, lpsD, lpsC, and lrp, transcribed in the reverse direction. Except for lpsB, none of the lps genes were relevant for nodulation and nitrogen fixation. Analysis of the transcriptional organization of lpsB showed that greA and lpsB are part of separate transcriptional units, which is in agreement with the finding of a DNA stretch homologous to a “nonnitrogen” promoter consensus sequence between greA and lpsB. The opposite orientation of lpsB with respect to its first downstream coding sequence, lpsE, indicated that the altered LPS and the defective symbiosis of lpsB mutants are both consequences of a primary nonpolar defect in a single gene. Global sequence comparisons revealed that the greA-lpsB and lrp genes of S. meliloti have a genetic organization similar to that of their homologous loci in R. leguminosarum bv. viciae. In particular, high sequence similarity was found between the translation product of lpsB and a core-related biosynthetic mannosyltransferase of R. leguminosarum bv. viciae encoded by the lpcC gene. The functional relationship between these two genes was demonstrated in genetic complementation experiments in which the S. meliloti lpsB gene restored the wild-type LPS phenotype when introduced into lpcC mutants of R. leguminosarum. These results support the view that S. meliloti lpsB also encodes a mannosyltransferase that participates in the biosynthesis of the LPS core. Evidence is provided for the presence of other lpsB-homologous sequences in several members of the family Rhizobiaceae. PMID:11157937

Diet-induced obesity attenuates endotoxin-induced cognitive deficits.

PubMed

Setti, Sharay E; Littlefield, Alyssa M; Johnson, Samantha W; Kohman, Rachel A

2015-03-15

Activation of the immune system can impair cognitive function, particularly on hippocampus dependent tasks. Several factors such as normal aging and prenatal experiences can modify the severity of these cognitive deficits. One additional factor that may modulate the behavioral response to immune activation is obesity. Prior work has shown that obesity alters the activity of the immune system. Whether diet-induced obesity (DIO) influences the cognitive deficits associated with inflammation is currently unknown. The present study explored whether DIO alters the behavioral response to the bacterial endotoxin, lipopolysaccharide (LPS). Female C57BL/6J mice were fed a high-fat (60% fat) or control diet (10% fat) for a total of five months. After consuming their respective diets for four months, mice received an LPS or saline injection and were assessed for alterations in spatial learning. One month later, mice received a second injection of LPS or saline and tissue samples were collected to assess the inflammatory response within the periphery and central nervous system. Results showed that LPS administration impaired spatial learning in the control diet mice, but had no effect in DIO mice. This lack of a cognitive deficit in the DIO female mice is likely due to a blunted inflammatory response within the brain. While cytokine production within the periphery (i.e., plasma, adipose, and spleen) was similar between the DIO and control mice, the DIO mice failed to show an increase in IL-6 and CD74 in the brain following LPS administration. Collectively, these data indicate that DIO can reduce aspects of the neuroinflammatory response as well as blunt the behavioral reaction to an immune challenge. Copyright © 2014 Elsevier Inc. All rights reserved.

Neural Substrate of Cold-Seeking Behavior in Endotoxin Shock

PubMed Central

Almeida, Maria C; Steiner, Alexandre A; Branco, Luiz G S; Romanovsky, Andrej A

2006-01-01

Systemic inflammation is a leading cause of hospital death. Mild systemic inflammation is accompanied by warmth-seeking behavior (and fever), whereas severe inflammation is associated with cold-seeking behavior (and hypothermia). Both behaviors are adaptive. Which brain structures mediate which behavior is unknown. The involvement of hypothalamic structures, namely, the preoptic area (POA), paraventricular nucleus (PVH), or dorsomedial nucleus (DMH), in thermoregulatory behaviors associated with endotoxin (lipopolysaccharide [LPS])-induced systemic inflammation was studied in rats. The rats were allowed to select their thermal environment by freely moving in a thermogradient apparatus. A low intravenous dose of Escherichia coli LPS (10 µg/kg) caused warmth-seeking behavior, whereas a high, shock-inducing dose (5,000 µg/kg) caused cold-seeking behavior. Bilateral electrocoagulation of the PVH or DMH, but not of the POA, prevented this cold-seeking response. Lesioning the DMH with ibotenic acid, an excitotoxin that destroys neuronal bodies but spares fibers of passage, also prevented LPS-induced cold-seeking behavior; lesioning the PVH with ibotenate did not affect it. Lesion of no structure affected cold-seeking behavior induced by heat exposure or by pharmacological stimulation of the transient receptor potential (TRP) vanilloid-1 channel (“warmth receptor”). Nor did any lesion affect warmth-seeking behavior induced by a low dose of LPS, cold exposure, or pharmacological stimulation of the TRP melastatin-8 (“cold receptor”). We conclude that LPS-induced cold-seeking response is mediated by neuronal bodies located in the DMH and neural fibers passing through the PVH. These are the first two landmarks on the map of the circuitry of cold-seeking behavior associated with endotoxin shock. PMID:17183631

Lipopolysaccharide modulation of a CD14-like molecule on porcine alveolar macrophages

NASA Technical Reports Server (NTRS)

Kielian, T. L.; Ross, C. R.; McVey, D. S.; Chapes, S. K.; Blecha, F.; Spooner, B. S. (Principal Investigator)

1995-01-01

Cluster of differentiation antigen 14 (CD14) functions as a receptor for lipopolysaccharide (LPS) LPS-binding protein (LBP) complexes. Because LPS has varying effects on CD14 expression in vitro, we evaluated CD14 expression in response to LPS with a fully differentiated macrophage phenotype, the alveolar macrophage. By using flow microfluorometric analysis and a radioimmunoassay with an anti-human CD14 monoclonal antibody (My4) that cross-reacts with porcine CD14, we found that macrophages stimulated with LPS for 24 h exhibited a two- to fivefold increase in CD14-like antigen compared with unstimulated cells. At low concentrations of LPS, up-regulation of the CD14-like antigen was dependent on serum; at higher concentrations of LPS, serum was not required. In the absence of serum a 10-fold higher dose of LPS (10 ng/ml) was required to increase CD14-like expression. In addition, LPS-induced CD14-like up-regulation correlated with secretion of tumor necrosis factor-alpha, regardless of serum concentration. Blockade with My4 antibody significantly inhibited LPS-induced tumor necrosis factor-alpha secretion at 1 ng/ml of LPS. However, inhibition decreased as we increased the LPS concentration, suggesting the existence of CD14-independent pathways of macrophage activation in response to LPS. Alternatively, My4 may have a lower affinity for the porcine CD14 antigen than LPS, which may have only partially blocked the LPS-LBP binding site at high concentrations of LPS. Therefore, these data suggest that LPS activation of porcine alveolar macrophages for 24 h increased CD14-like receptor expression. The degree of CD14-like up-regulation was related to LPS concentration, however, activation did not require the presence of serum at high concentrations of LPS.

Stimulation of the α7 nicotinic acetylcholine receptor protects against neuroinflammation after tibia fracture and endotoxemia in mice.

PubMed

Terrando, Niccolò; Yang, Ting; Ryu, Jae Kyu; Newton, Phillip T; Monaco, Claudia; Feldmann, Marc; Ma, Daqing; Akassoglou, Katerina; Maze, Mervyn

2015-03-17

Surgery and critical illness often associate with cognitive decline. Surgical trauma or infection can lead independently to learning and memory impairments via similar, but not identical, cellular signaling of the innate immune system that promotes neuroinflammation. In this study we explored the putative synergism between aseptic orthopedic surgery and infection, the latter reproduced by postoperative lipopolysaccharide (LPS) administration. We observed that surgery and LPS augmented systemic inflammation up to postoperative d 3 and this was associated with further neuroinflammation (CD11b and CD68 immunoreactivity) in the hippocampus in mice compared with those receiving surgery or LPS alone. Administration of a selective α7 subtype nicotinic acetylcholine receptor (α7 nAChR) agonist 2 h after LPS significantly improved neuroinflammation and hippocampal-dependent memory dysfunction. Modulation of nuclear factor-kappa B (NF-κB) activation in monocytes and regulation of the oxidative stress response through nicotinamide adenine dinucleotide phosphate (NADPH) signaling appear to be key targets in modulating this response. Overall, these results suggest that it may be conceivable to limit and possibly prevent postoperative complications, including cognitive decline and/or infections, through stimulation of the cholinergic antiinflammatory pathway.

Emphysema induced by elastase enhances acute inflammatory pulmonary response to intraperitoneal LPS in rats.

PubMed

da Fonseca, Lídia Maria Carneiro; Reboredo, Maycon Moura; Lucinda, Leda Marília Fonseca; Fazza, Thaís Fernanda; Rabelo, Maria Aparecida Esteves; Fonseca, Adenilson Souza; de Paoli, Flavia; Pinheiro, Bruno Valle

2016-12-01

Abnormalities in lungs caused by emphysema might alter their response to sepsis and the occurrence of acute lung injury (ALI). This study compared the extension of ALI in response to intraperitoneal lipopolysaccharide (LPS) injection in Wistar rats with and without emphysema induced by elastase. Adult male Wistar rats were randomized into four groups: control, emphysema without sepsis, normal lung with sepsis and emphysema with sepsis. Sepsis was induced, and 24 h later the rats were euthanised. The following analysis was performed: blood gas measurements, bronchoalveolar lavage (BAL), lung permeability and histology. Animals that received LPS showed significant increase in a lung injury scoring system, inflammatory cells in bronchoalveolar lavage (BAL) and IL-6, TNF-α and CXCL2 mRNA expression in lung tissue. Animals with emphysema and sepsis showed increased alveolocapillary membrane permeability, demonstrated by higher BAL/serum albumin ratio. In conclusion, the presence of emphysema induced by elastase increases the inflammatory response in the lungs to a systemic stimulus, represented in this model by the intraperitoneal injection of LPS. © 2016 The Authors. International Journal of Experimental Pathology © 2016 International Journal of Experimental Pathology.

Herbal medicine IMOD suppresses LPS-induced production of proinflammatory cytokines in human dendritic cells

PubMed Central

Mirzaee, Saeedeh; Drewniak, Agata; Sarrami-Forooshani, Ramin; Kaptein, Tanja M.; Gharibdoost, Farhad; Geijtenbeek, Teunis B. H.

2015-01-01

Traditional medicines that stimulate or modulate the immune system can be used as innovative approaches to treat immunological diseases. The herbal medicine IMOD has been shown to strongly modulate immune responses in several animal studies as well as in clinical trials. However, little is known about the mechanisms of IMOD to modulate immunity. Here we have investigated whether IMOD modulates the immunological function of human dendritic cells (DCs). IMOD alone did not induce DC maturation nor production of cytokines. Notably, IMOD decreased the production of pro-inflammatory cytokines IL-6, IL-12 p70, and TNFα by LPS-activated DCs at both mRNA and protein levels in a dose dependent manner. In contrast, treatment with IMOD did not affect LPS induced-production of the anti-inflammatory cytokine IL-10. Furthermore, IMOD inhibited T cell activation/proliferation by LPS-treated DCs and skewed T-cells responses toward the T helper type 2 polarization. These data strongly indicate that IMOD has a potent immunomodulatory ability that affects TLR signaling and thereby modulates DC function. Insight into the immunomodulatory effect of herbal medicine IMOD may provide innovative strategies to affect the immune system and to help combat various diseases. PMID:25870561

Investigation of Anti-Infection Mechanism of Lactoferricin and Splunc-1

PubMed Central

Tsou, Yung An; Huang, Hung-Jin; Lin, Wesley Wen Yang; Chen, Calvin Yu-Chian

2014-01-01

The innate immune system is the first line in the defense system and prevents the body from further bacteria, virus, or fungal infections. Most of the innate immune system is relevant to mucosa immunity. Lactotransferrin is secreted from the human mammal breast duct epithelial tissue and strengthens infant immunity to defense with regard to outward pathogens. Splunc-1 is also an innate material secreted from the soft palate, lung, nasal cavity epithelium, and mucosa. It helps with mucosa defense against bacterial, virus, and even fungus. LPS is the main etiology of Gram-negative bacilla infection source. And studies of lactoferricin and slpunc-1 both can combine with LPS and subsequently cause insults to the mucosa. Although, we know that both of them partake in an important role in innate immunity, we do not know the effects when they work together. In this study, we just overview silicon stimulation to examine the combination of Lactoferricin and Splunc-1 and the effect with regard to LPS. PMID:24876880

Ceftaroline modulates the innate immune and host defense responses of immunocompetent cells exposed to cigarette smoke.

PubMed

Bruno, A; Cipollina, C; Di Vincenzo, S; Siena, L; Dino, P; Di Gaudio, F; Gjomarkaj, M; Pace, E

2017-09-05

Cigarette smoke, the principal risk factor for chronic obstructive pulmonary disease (COPD), negatively influences the effectiveness of the immune system's response to a pathogen. The antibiotic ceftaroline exerts immune-modulatory effects in bronchial epithelial cells exposed to cigarette smoke. The present study aims to assess the effects of ceftaroline on TLR2 and TLR4 expression, LPS binding and TNF-α and human beta defensin (HBD2) release in an undifferentiated and PMA-differentiated human monocyte cell line (THP-1) exposed or not to cigarette smoke extracts (CSE). TLR2, TLR4, and LPS binding were assessed by flow cytometry, TNF-α and HBD2 release were evaluated by ELISA. The constitutive expression of TLR2 and TLR4 and LPS binding were higher in differentiated compared to undifferentiated THP-1 cells. In undifferentiated THP-1 cells, CSE increased TLR2 and TLR4 protein levels, LPS binding and TNF-α release and reduced HBD2 release and ceftaroline counteracted all these effects. In differentiated THP-1, CSE did not significantly affect TLR2 and TLR4 expression and LPS binding but reduced HBD2 release and increased TNF-α release. Ceftaroline counteracted the effects of CSE on HBD2 release in differentiated THP-1. Ceftaroline counteracts the effect of CSE in immune cells by increasing the effectiveness of the innate immune system. This effect may also assist in reducing pathogen activity and recurrent exacerbations in COPD patients. Copyright © 2017 Elsevier B.V. All rights reserved.

Oxytocin's role on the cardiorespiratory activity of endotoxemic rats.

PubMed

Elorza-Ávila, Ana Rosa; Reyes-Lagos, José Javier; Hadamitzky, Martin; Peña-Castillo, Miguel Ángel; Echeverría, Juan Carlos; Ortiz-Pedroza, María Del Rocío; Lückemann, Laura; Schedlowski, Manfred; Pacheco-López, Gustavo

2017-02-01

Recent findings concerning oxytocin indicate its anti-inflammatory, cardioprotective and parasympathetic modulating properties. In this study, we investigated the effects of systemically applied oxytocin on the cardiorespiratory activity in a rodent model of moderate endotoxemia. Telemetrically recorded electrocardiogram (ECGs) from animals which received lipopolysaccharide (LPS); oxytocin (Ox); lipopolysaccharide+oxytocin (LPS+Ox), or vehicle (V) were analyzed using the ECG-derived respiration (EDR) technique to estimate the respiratory rate. The mean R-R interval and the spectral parameters of heart rate variability (HRV), such as the natural logarithm of the high frequency (lnHF) and low frequency (lnLF) components were also estimated up to 24h after treatment. The endotoxemic animals (LPS) showed an elevated respiratory rate as well as a reduced mean R-R interval, lnHF and lnLF components compared to controls (V) from +5 to +12h after the treatment. The administration of oxytocin significantly attenuated the hyperventilation produced by the LPS-induced endotoxemia (LPS+Ox) and restored the values of the mean R-R interval and such spectral parameters at different time points. Our results support the existence of a link among the respiratory, cardiovascular, and immune systems in which oxytocin seems to act as a potential cardioprotective peptide by favoring cardiac cholinergic autonomic coupling. As a result, oxytocin diminished animal's endotoxemic tachypnea and restored the cardiorespiratory interactions, which was indicated by the spectral components of HRV. Copyright © 2016 Elsevier B.V. All rights reserved.

Role of cyclooxygenase-2 in intestinal injury in neonatal rats.

PubMed

Lu, Hui; Zhu, Bing

2014-11-01

Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency in premature neonates. The pathogenesis of NEC remains poorly understood. The present study aimed to investigate the dynamic change and role of cyclooxygenase-2 (COX-2) in neonatal rats with intestinal injury. Wistar rats, <24 h in age, received an intraperitoneal injection with 5 mg/kg lipopolysaccharide (LPS). Ileal tissues were collected at 1, 3, 6, 12 and 24 h following the LPS challenge for histological evaluation of NEC and for measurements of COX-2 mRNA. The correlation between the degree of intestinal injury and expression of COX-2 mRNA was determined. The LPS-injected pups showed a significant increase in injury scores compared to the control, and the most deteriorating change was at 12 h. COX-2 mRNA expression was upregulated following LPS injection. There was a significantly positive correlation between COX-2 mRNA and the grade of intestinal injury within 12 h, whereas COX-2 mRNA expression had a significantly negative correlation with the severity of intestinal injury at 24 h. COX-2 plays an important role in LPS-induced intestinal injury and the repair processes. Caution should be exerted concerning the potential therapeutic uses of COX-2 inhibitors or promoters in NEC.

Murine J774 Macrophages Recognize LPS/IFN-g, Non-CpG DNA or Two-CpG DNA-containing Sequences as Immunologically Distinct

PubMed Central

Crosby, Lynn; Casey, Warren; Morgan, Kevin; Ni, Hong; Yoon, Lawrence; Easton, Marilyn; Misukonis, Mary; Burleson, Gary; Ghosh, Dipak K.

2010-01-01

Specific bacterial lipopolysaccharides (LPS), IFN-γ, and unmethylated cytosine or guanosine-phosphorothioate containing DNAs (CpG) activate host immunity, influencing infectious responses. Macrophages detect, inactivate and destroy infectious particles, and synthetic CpG sequences invoke similar responses of the innate immune system. Previously, murine macrophage J774 cells treated with CpG induced the expression of nitric oxide synthase 2 (NOS2) and cyclo-oxygenase 2 (COX2) mRNA and protein. In this study murine J774 macrophages were exposed to vehicle, interferon γ + lipopolysaccharide (IFN-g/LPS), non-CpG (SAK1), or two-CpG sequence-containing DNA (SAK2) for 0–18 hr and gene expression changes measured. A large number of immunostimulatory and inflammatory changes were observed. SAK2 was a stronger activator of TNFα- and chemokine expression-related changes than LPS/IFN-g. Up regulation included tumor necrosis factor receptor superfamily genes (TNFRSF’s), IL-1 receptor signaling via stress-activated protein kinase (SAPK), NF-κB activation, hemopoietic maturation factors and sonic hedgehog/wingless integration site (SHH/Wnt) pathway genes. Genes of the TGF-β pathway were down regulated. In contrast, LPS/IFN-g -treated cells showed increased levels for TGF-β signaling genes, which may be linked to the observed up regulation of numerous collagens and down regulation of Wnt pathway genes. SAK1 produced distinct changes from LPS/IFN-g or SAK2. Therefore, J774 macrophages recognize LPS/IFN-g, non-CpG DNA or two-CpG DNA-containing sequences as immunologically distinct. PMID:20097302

Circadian Disruption Alters the Effects of Lipopolysaccharide Treatment on Circadian and Ultradian Locomotor Activity and Body Temperature Rhythms of Female Siberian Hamsters

PubMed Central

Prendergast, Brian J.; Cable, Erin J.; Stevenson, Tyler J.; Onishi, Kenneth G.; Zucker, Irving; Kay, Leslie M.

2016-01-01

The effect of circadian rhythm (CR) disruption on immune function depends on the method by which CRs are disrupted. Behavioral and thermoregulatory responses induced by lipopolysaccharide (LPS) treatment were assessed in female Siberian hamsters in which circadian locomotor activity (LMA) rhythms were eliminated by exposure to a disruptive phase-shifting protocol (DPS) that sustains arrhythmicity even when hamsters are housed in a light-dark cycle. This noninvasive treatment avoids genome manipulations and neurological damage associated with other models of CR disruption. Circadian rhythmic (RHYTH) and arrhythmic (ARR) hamsters housed in a 16L:8D photocycle were injected with bacterial LPS near the onset of the light (zeitgeber time 1; ZT1) or dark (ZT16) phase. LPS injections at ZT16 and ZT1 elicited febrile responses in both RHYTH and ARR hamsters, but the effect was attenuated in the arrhythmic females. In ZT16, LPS inhibited LMA in the dark phase immediately after injection but not on subsequent nights in both chronotypes; in contrast, LPS at ZT1 elicited more enduring (~4 day) locomotor hypoactivity in ARR than in RHYTH hamsters. Power and period of dark-phase ultradian rhythms (URs) in LMA and Tb were markedly altered by LPS treatment, as was the power in the circadian waveform. Disrupted circadian rhythms in this model system attenuated responses to LPS in a trait- and ZT-specific manner; changes in UR period and power are novel components of the acute-phase response to infection that may affect energy conservation. PMID:26566981

Posttreatment with Ma-Xing-Shi-Gan-Tang, a Chinese medicine formula, ameliorates lipopolysaccharide-induced lung microvessel hyperpermeability and inflammatory reaction in rat.

PubMed

Ma, Li-Qian; Pan, Chun-Shui; Yang, Ning; Liu, Yu-Ying; Yan, Li; Sun, Kai; Wei, Xiao-Hong; He, Ke; Xiao, Meng-Meng; Fan, Jing-Yu; Han, Jing-Yan

2014-10-01

The aim of present study was to investigate the efficacy of MXSGT, a traditional Chinese medicine formula used for treatment of respiratory system diseases, in the LPS-induced rat ALI particularly with a focus on its effect on lung microvascular hyperpermeability and inflammatory reaction. Male Sprague-Dawley rats were injected with LPS (7.5 mg/kg, 1.5 mg/mL) intraperitoneally. MXSGT (0.52 g or 2.61 g/kg) was given by gavage six hours after LPS injection. LPS stimulation resulted in a reduced survival rate, deteriorated vital signs, an increase in the number of leukocytes adhering to lung venules, the albumin leakage, the activity of MPO in lung tissues, the production of pro-inflammatory cytokines and lung perivascular edema. After LPS stimulation, western blot analysis revealed an increase in the expression of ICAM-1 and toll-like receptor 4, a decrease in tight junction proteins and an activation of cav-1, Src, and NF-κB. All the LPS-induced alterations were significantly attenuated by posttreatment with MXSGT. This study demonstrated MXSGT as a potential strategy for lung microvascular hyperpermeability and inflammatory reaction in ALI, and suggested that the beneficial role of MXSGT was correlated with toll-like receptor 4, Src, and NF-κB. © 2014 John Wiley & Sons Ltd.

C-glycosylflavones from the aerial parts of Eleusine indica inhibit LPS-induced mouse lung inflammation.

PubMed

De Melo, Giany O; Muzitano, Michelle F; Legora-Machado, Alexandre; Almeida, Thais A; De Oliveira, Daniela B; Kaiser, Carlos R; Koatz, Vera Lucia G; Costa, Sônia S

2005-04-01

The infusion of aerial parts (EI) of Eleusine indica Gaertn (Poaceae) is used in Brazil against airway inflammatory processes like influenza and pneumonia. Pre-treatment with 400 mg/kg of crude extract inhibited 98% of lung neutrophil recruitment in mice exposed to aerosols of lipopolysaccharide (LPS) from Gram-negative bacteria, in a dose-dependent manner. At 400 microg/kg, schaftoside (6-C-beta-glucopyranosyl-8-C-alpha-arabinopyranosylapigenin) and vitexin (8-C-beta-glucopyranosylapigenin), isolated from EI, inhibited 62% and 80% of lung neutrophil influx, respectively. These results may justify the popular use of E. indica against airway inflammatory processes.

Pyrrolidine Dithiocarbamate Prevents Neuroinflammation and Cognitive Dysfunction after Endotoxemia in Rats

PubMed Central

Kan, Min Hui; Yang, Ting; Fu, Hui Qun; Fan, Long; Wu, Yan; Terrando, Niccolò; Wang, Tian-Long

2016-01-01

Systemic inflammation, for example as a result of infection, often contributes to long-term complications. Neuroinflammation and cognitive decline are key hallmarks of several neurological conditions, including advance age. The contribution of systemic inflammation to the central nervous system (CNS) remains not fully understood. Using a model of peripheral endotoxemia with lipopolysaccharide (LPS) we investigated the role of nuclear factor-κB (NF-κB) activity in mediating long-term neuroinflammation and cognitive dysfunction in aged rats. Herein we describe the anti-inflammatory effects of pyrrolidine dithiocarbamate (PDTC), a selective NF-κB inhibitor, in modulating systemic cytokines including tumor necrosis factor (TNF)-α and interleukin-1β (IL-1β) and CNS markers after LPS exposure in aged rats. In the hippocampus, PDTC not only reduced neuroinflammation by modulating canonical NF-κB activity but also affected IL-1β expression in astrocytes. Parallel effects were observed on behavior and postsynaptic density-95 (PSD95), a marker of synaptic function. Taken together these changes improved acute and long-term cognitive function in aged rats after LPS exposure. PMID:27493629

Poleward shift and weakening of summer season synoptic activity over India in a warming climate

NASA Astrophysics Data System (ADS)

Ravindran, A. M.; Sandeep, S.; Boos, W. R.; TP, S.; Praveen, V.

2017-12-01

One of the main components of the Indian summer monsoon is the presence of low intensity cyclonic systems popularly known as Low Pressure Systems (LPS), which contribute more than half of the precipitation received over the fertile Central Indian region. An average of 13 (±2.5) storms develop each boreal summer, with most originating over the Bay of Bengal (BoB) and adjoining land. These systems typically follow a north-west track along the monsoon trough. Despite its significance, the future variability of these storms is not studied, due to the inadequate representation of these systems in current generation climate models. A series of numerical experiments are performed here using the High Resolution Atmospheric Model (HiRAM) with a horizontal grid spacing of 50 km globally to simulate these rain-bearing systems. One set of simulations represents the historical (HIST) period and the other a late 21st century climate scenario based on the strongest Representative Concentration Pathway (RCP8.5). Four ensemble members of these simulations are run, with sea surface temperatures (SSTs) taken from different CMIP5 GCMs selected for their skill in simulating the Indian monsoon. In addition, ten ensemble members of `decadal' experiments are run for both HIST and RCP8.5 to assess model uncertainty, in which the model is forced with annual cycles of decadal mean SSTs. We show that the strength of monsoon LPS activity would decline as much as 50% by the end of the 21st century, under business as usual emission scenario. The overall reduction in the LPS activity is contributed by a 60% decrease in the frequency of storms over the Bay of Bengal, while the weaker systems that form over the land has increased 10% in a warmer climate. Further analysis suggests that a relatively slower rate of warming over the Bay of Bengal compared to the surrounding regions has resulted in an enhanced moist stability over the main genesis region of LPS, which in turn suppressed the growth of these storms in a warmer climate. The change in extreme precipitation may be mentioned as a consequence of ocean-to-land shift in LPS activity.

Neoadjuvant radiation in primary extremity liposarcoma: correlation of MRI features with histopathology.

PubMed

Wortman, Jeremy R; Tirumani, Sree Harsha; Tirumani, Harika; Shinagare, Atul B; Jagannathan, Jyothi P; Hornick, Jason L; Ramaiya, Nikhil H

2016-05-01

To evaluate MRI features of response of primary extremity liposarcoma (LPS) to neoadjuvant radiation therapy (RT) with histopathologic correlation. In this IRB-approved study including 125 patients with extremity LPS treated with neoadjuvant RT from 2000 to 2013, MRI of the primary tumour in 18 patients (5 pleomorphic LPS, 13 myxoid LPS) before and after RT were reviewed by two radiologists by consensus. Histopathology of the surgical specimens was reviewed by a pathologist with expertise in sarcomas. In the pleomorphic LPS cohort, 3/5 tumours increased in size; 3/5 decreased in enhancing component; and 3/5 increased in peritumoral oedema, intratumoral haemorrhage, and necrosis. In the myxoid LPS cohort, 12/13 tumours decreased in size, 8/13 decreased in enhancing component, and 5/13 increased in internal fat following RT. Histopathology showed ≥50% residual tumour in 1/5 pleomorphic LPS and 2/13 myxoid LPS. Hyalinization/necrosis of ≥75% was noted in 4/5 pleomorphic LPS and 11/13 myxoid LPS. Cytodifferentiation was noted in 1/5 pleomorphic and 9/13 myxoid LPS. While pleomorphic LPS showed an increase in size, peritumoral oedema, intratumoral haemorrhage, and necrosis on MRI following neoadjuvant RT, myxoid LPS showed a decrease in size and enhancement with an increase in internal fat. • Pleomorphic LPS commonly increase in size and necrosis on MRI following RT. • Myxoid LPS commonly decrease in size and enhancement on MRI following RT. • Myxoid LPS often increase in fatty component on MRI following RT.

Prior exposure to corticosterone markedly enhances and prolongs the neuroinflammatory response to systemic challenge with LPS

PubMed Central

Michalovicz, Lindsay T.; Miller, Julie V.; Castranova, Vincent; Miller, Diane B.

2018-01-01

Systemic exposure to the inflammagen and bacterial endotoxin lipopolysaccharide (LPS) has been widely used to evaluate inflammation and sickness behavior. While many inflammatory conditions occur in the periphery, it is well established that peripheral inflammation can affect the brain. Neuroinflammation, the elaboration of proinflammatory mediators in the CNS, commonly is associated with behavioral symptoms (e.g., lethargy, anhedonia, anorexia, depression, etc.) termed sickness behavior. Stressors have been shown to interact with and alter neuroinflammatory responses and associated behaviors. Here, we examined the effects of the stress hormone, corticosterone (CORT), as a stressor mimic, on neuroinflammation induced with a single injection (2mg/kg, s.c.) or inhalation exposure (7.5 μg/m3) of LPS or polyinosinic:polycytidylic acid (PIC; 12mg/kg, i.p.) in adult male C57BL/6J mice. CORT was given in the drinking water (200 mg/L) for 1 week or every other week for 90 days followed by LPS. Proinflammatory cytokine expression (TNFα, IL-6, CCL2, IL-1β, LIF, and OSM) was measured by qPCR. The activation of the neuroinflammation downstream signaling activator, STAT3, was assessed by immunoblot of pSTAT3Tyr705. The presence of astrogliosis was assessed by immunoassay of GFAP. Acute exposure to LPS caused brain-wide neuroinflammation without producing astrogliosis; exposure to CORT for 1 week caused marked exacerbation of the LPS-induced neuroinflammation. This neuroinflammatory “priming” by CORT was so pronounced that sub-neuroinflammatory exposures by inhalation instigated neuroinflammation when paired with prior CORT exposure. This effect also was extended to another common inflammagen, PIC (a viral mimic). Furthermore, a single week of CORT exposure maintained the potential for priming for 30 days, while intermittent exposure to CORT for up to 90 days synergistically primed the LPS-induced neuroinflammatory response. These findings highlight the possibility for an isolated inflammatory event to be exacerbated by a temporally distant stressful stimulus and demonstrates the potential for recurrent stress to greatly aggravate chronic inflammatory disorders. PMID:29304053

Bacterial Lipopolysaccharide Destabilizes Influenza Viruses.

PubMed

Bandoro, Christopher; Runstadler, Jonathan A

2017-01-01

Depending on the specific viral pathogen, commensal bacteria can promote or reduce the severity of viral infection and disease progression in their hosts. Influenza A virus (IAV) has a broad host range, comprises many subtypes, and utilizes different routes of transmission, including the fecal-oral route in wild birds. It has been previously demonstrated that commensal bacteria can interact with the host's immune system to protect against IAV pathogenesis. However, it is unclear whether bacteria and their products may be interacting directly with IAV to impact virion stability. Herein we show that gastrointestinal (GI) tract bacterial isolates in an in vitro system significantly reduce the stability of IAV. Moreover, bacterial lipopolysaccharide (LPS), found on the exterior surfaces of bacteria, was sufficient to significantly decrease the stability of both human and avian viral strains in a temperature-dependent manner, including at the relevant temperatures of their respective hosts and the external aquatic habitat. The subtype and host origin of the viruses were shown to affect the extent to which IAV was susceptible to LPS. Furthermore, using a receptor binding assay and transmission electron microscopy, we observed that LPS binds to and alters the morphology of influenza virions, suggesting that direct interaction with the viral surface contributes to the observed antiviral effect of LPS on influenza. IMPORTANCE Influenza A virus (IAV), transmitted primarily via the fecal-oral route in wild birds, encounters high concentrations of bacteria and their products. Understanding the extent to which bacteria affect the infectivity of IAV will lead to a broader understanding of viral ecology in reservoir hosts and may lead to insights for the development of therapeutics in respiratory infection. Herein we show that bacteria and lipopolysaccharide (LPS) interact with and destabilize influenza virions. Moreover, we show that LPS reduces the long-term persistence and freeze-thaw stability of IAV, which is important information for modeling the movement and emergence of novel strains from animal hosts. Our results, demonstrating that the subtype and host origin of a virus also influence its susceptibility to LPS, raise key questions about the fitness of viruses in reservoir hosts, their potential to transmit to humans, and the importance of bacterial-viral interactions in viral ecology.

Bacterial Lipopolysaccharide Destabilizes Influenza Viruses

PubMed Central

2017-01-01

ABSTRACT Depending on the specific viral pathogen, commensal bacteria can promote or reduce the severity of viral infection and disease progression in their hosts. Influenza A virus (IAV) has a broad host range, comprises many subtypes, and utilizes different routes of transmission, including the fecal-oral route in wild birds. It has been previously demonstrated that commensal bacteria can interact with the host’s immune system to protect against IAV pathogenesis. However, it is unclear whether bacteria and their products may be interacting directly with IAV to impact virion stability. Herein we show that gastrointestinal (GI) tract bacterial isolates in an in vitro system significantly reduce the stability of IAV. Moreover, bacterial lipopolysaccharide (LPS), found on the exterior surfaces of bacteria, was sufficient to significantly decrease the stability of both human and avian viral strains in a temperature-dependent manner, including at the relevant temperatures of their respective hosts and the external aquatic habitat. The subtype and host origin of the viruses were shown to affect the extent to which IAV was susceptible to LPS. Furthermore, using a receptor binding assay and transmission electron microscopy, we observed that LPS binds to and alters the morphology of influenza virions, suggesting that direct interaction with the viral surface contributes to the observed antiviral effect of LPS on influenza. IMPORTANCE Influenza A virus (IAV), transmitted primarily via the fecal-oral route in wild birds, encounters high concentrations of bacteria and their products. Understanding the extent to which bacteria affect the infectivity of IAV will lead to a broader understanding of viral ecology in reservoir hosts and may lead to insights for the development of therapeutics in respiratory infection. Herein we show that bacteria and lipopolysaccharide (LPS) interact with and destabilize influenza virions. Moreover, we show that LPS reduces the long-term persistence and freeze-thaw stability of IAV, which is important information for modeling the movement and emergence of novel strains from animal hosts. Our results, demonstrating that the subtype and host origin of a virus also influence its susceptibility to LPS, raise key questions about the fitness of viruses in reservoir hosts, their potential to transmit to humans, and the importance of bacterial-viral interactions in viral ecology. PMID:29034326

HemoHIM, a herbal preparation, alleviates airway inflammation caused by cigarette smoke and lipopolysaccharide.

PubMed

Shin, Na-Rae; Kim, Sung-Ho; Ko, Je-Won; Park, Sung-Hyeuk; Lee, In-Chul; Ryu, Jung-Min; Kim, Jong-Choon; Shin, In-Sik

2017-03-01

HemoHIM, herbal preparation has designed for immune system recovery. We investigated the anti-inflammatory effect of HemoHIM on cigarette smoke (CS) and lipopolysaccharide (LPS) induced chronic obstructive pulmonary disease (COPD) mouse model. To induce COPD, C57BL/6 mice were exposed to CS for 1 h per day (eight cigarettes per day) for 4 weeks and intranasally received LPS on day 26. HemoHIM was administrated to mice at a dose of 50 or 100 mg/kg 1h before CS exposure. HemoHIM reduced the inflammatory cell count and levels of tumor necrosis factor receptor (TNF)-α, interleukin (IL)-6 and IL-1β in the broncho-alveolar lavage fluid (BALF) induced by CS+LPS exposure. HemoHIM decreased the inflammatory cell infiltration in the airway and inhibited the expression of iNOS and MMP-9 and phosphorylation of Erk in lung tissue exposed to CS+LPS. In summary, our results indicate that HemoHIM inhibited a reduction in the lung inflammatory response on CS and LPS induced lung inflammation via the Erk pathway. Therefore, we suggest that HemoHIM has the potential to treat pulmonary inflammatory disease such as COPD.

Inhibitory effects of the methylene chloride fraction of JP05 on the production of inflammatory mediators in LPS-activated BV2 microglia.

PubMed

Jung, Hyo Won; Oh, Tae Woo; Jung, Jin Ki; Lee, Je-Hyun; Shin, Gil Jo; Park, Yong-Ki

2012-02-01

Excessive production of inflammatory mediators such as nitric oxide (NO) and proinflammatory cytokines from activated microglia in the central nervous system contributes to uncontrolled inflammation in neurodegenerative disorders. In this study, we investigated the anti-inflammatory activities of the methylene chloride fraction of JP05 (JP05-MC) on the production of inflammatory mediators in lipopolysaccharide (LPS)-stimulated BV2 mouse microglial cells, and its mechanism of action. JP05-MC significantly inhibited LPS-induced production of NO and the proinflammatory cytokines, TNF-α and IL-6, in BV2 cells. JP05-MC also attenuated the mRNA expression and protein levels of inducible nitric oxide synthase in LPS-induced BV2 cells. JP05-MC significantly attenuated LPS-elicited phosphorylation of the mitogen-activated protein kinase (MAPK), extracellular-signal-regulated kinase 1/2, and nuclear factor-κB (NF-κB) nuclear translocation in BV2 cells. Our results indicate that JP05-MC exerts anti-inflammatory properties via downregulation of inflammatory mediator gene transcription by suppressing the MAPK and NF-κB pathways, suggesting that JP05-MC may have therapeutic potential as an anti-inflammatory agent in neurodegenerative diseases.

Lipopolysaccharides from Commensal and Opportunistic Bacteria: Characterization and Response of the Immune System of the Host Sponge Suberites domuncula

PubMed Central

Gardères, Johan; Bedoux, Gilles; Koutsouveli, Vasiliki; Crequer, Sterenn; Desriac, Florie; Le Pennec, Gaël

2015-01-01

Marine sponges harbor a rich bacterioflora with which they maintain close relationships. However, the way these animals make the distinction between bacteria which are consumed to meet their metabolic needs and opportunistic and commensal bacteria which are hosted is not elucidated. Among the elements participating in this discrimination, bacterial cell wall components such as lipopolysaccharides (LPS) could play a role. In the present study, we investigated the LPS chemical structure of two bacteria associated with the sponge Suberites domuncula: a commensal Endozoicomonas sp. and an opportunistic Pseudoalteromonas sp. Electrophoretic patterns indicated different LPS structures for these bacteria. The immunomodulatory lipid A was isolated after mild acetic acid hydrolysis. The electrospray ionization ion-trap mass spectra revealed monophosphorylated molecules corresponding to tetra- and pentaacylated structures with common structural features between the two strains. Despite peculiar structural characteristics, none of these two LPS influenced the expression of the macrophage-expressed gene S. domuncula unlike the Escherichia coli ones. Further research will have to include a larger number of genes to understand how this animal can distinguish between LPS with resembling structures and discriminate between bacteria associated with it. PMID:26262625

HemoHIM, a herbal preparation, alleviates airway inflammation caused by cigarette smoke and lipopolysaccharide

PubMed Central

Shin, Na-Rae; Kim, Sung-Ho; Ko, Je-Won; Park, Sung-Hyeuk; Lee, In-Chul; Ryu, Jung-Min; Kim, Jong-Choon

2017-01-01

HemoHIM, herbal preparation has designed for immune system recovery. We investigated the anti-inflammatory effect of HemoHIM on cigarette smoke (CS) and lipopolysaccharide (LPS) induced chronic obstructive pulmonary disease (COPD) mouse model. To induce COPD, C57BL/6 mice were exposed to CS for 1 h per day (eight cigarettes per day) for 4 weeks and intranasally received LPS on day 26. HemoHIM was administrated to mice at a dose of 50 or 100 mg/kg 1h before CS exposure. HemoHIM reduced the inflammatory cell count and levels of tumor necrosis factor receptor (TNF)-α, interleukin (IL)-6 and IL-1β in the broncho-alveolar lavage fluid (BALF) induced by CS+LPS exposure. HemoHIM decreased the inflammatory cell infiltration in the airway and inhibited the expression of iNOS and MMP-9 and phosphorylation of Erk in lung tissue exposed to CS+LPS. In summary, our results indicate that HemoHIM inhibited a reduction in the lung inflammatory response on CS and LPS induced lung inflammation via the Erk pathway. Therefore, we suggest that HemoHIM has the potential to treat pulmonary inflammatory disease such as COPD. PMID:28400838

The Role of Smurf1 in Neuronal Necroptosis after Lipopolysaccharide-Induced Neuroinflammation.

PubMed

Shao, Lifei; Liu, Xiaojuan; Zhu, Shunxing; Liu, Chun; Gao, Yilu; Xu, Xide

2018-05-01

The role of inflammation in neurological disorders such as Alzheimer's disease and Parkinson's disease is gradually recognized and leads to an urgent challenge. Smad ubiquitination regulatory factor 1 (Smurf1), one member of the HECT family, is up-regulated by proinflammatory cytokines and associated with apoptosis in acute spinal cord injury. However, the function of Smurf1 through promoting neuronal necroptosis is still limited in the central nervous system (CNS). Hence, we developed a neuroinflammatory model in adult rats following lipopolysaccharide (LPS) lateral ventral injection to elaborate whether Smurf1 is involved in necroptosis in CNS injury. The up-regulation of Smurf1 detected in the rat brain cortex was similar to the necroptotic marker RIP1 expression in a time-dependent manner after LPS-induced neuroinflammation. Meanwhile, Smurf1 knockdown with siRNA inhibited neuronal necroptosis following LPS-stimulated rat pheochromocytomal PC12 cells. Thus, it was indicated that LPS-induced necroptosis could be promoted by Smurf1. In short, these studies suggest that Smurf1 might promote neuronal necroptosis after LPS-induced neuroinflammation, which might act as a novel and potential molecular target for the treatment of neuroinflammation associated diseases.

Untargeted metabolomics analysis reveals dynamic changes in azelaic acid- and salicylic acid derivatives in LPS-treated Nicotiana tabacum cells.

PubMed

Mhlongo, M I; Tugizimana, F; Piater, L A; Steenkamp, P A; Madala, N E; Dubery, I A

2017-01-22

To counteract biotic stress factors, plants employ multilayered defense mechanisms responsive to pathogen-derived elicitor molecules, and regulated by different phytohormones and signaling molecules. Here, lipopolysaccharide (LPS), a microbe-associated molecular pattern (MAMP) molecule, was used to induce defense responses in Nicotiana tabacum cell suspensions. Intracellular metabolites were extracted with methanol and analyzed using a liquid chromatography-mass spectrometry (UHPLC-qTOF-MS/MS) platform. The generated data were processed and examined with multivariate and univariate statistical tools. The results show time-dependent dynamic changes and accumulation of glycosylated signaling molecules, specifically those of azelaic acid, salicylic acid and methyl-salicylate as contributors to the altered metabolomic state in LPS-treated cells. Copyright © 2016 Elsevier Inc. All rights reserved.

[3D visualization and analysis of vocal fold dynamics].

PubMed

Bohr, C; Döllinger, M; Kniesburges, S; Traxdorf, M

2016-04-01

Visual investigation methods of the larynx mainly allow for the two-dimensional presentation of the three-dimensional structures of the vocal fold dynamics. The vertical component of the vocal fold dynamics is often neglected, yielding a loss of information. The latest studies show that the vertical dynamic components are in the range of the medio-lateral dynamics and play a significant role within the phonation process. This work presents a method for future 3D reconstruction and visualization of endoscopically recorded vocal fold dynamics. The setup contains a high-speed camera (HSC) and a laser projection system (LPS). The LPS projects a regular grid on the vocal fold surfaces and in combination with the HSC allows a three-dimensional reconstruction of the vocal fold surface. Hence, quantitative information on displacements and velocities can be provided. The applicability of the method is presented for one ex-vivo human larynx, one ex-vivo porcine larynx and one synthetic silicone larynx. The setup introduced allows the reconstruction of the entire visible vocal fold surfaces for each oscillation status. This enables a detailed analysis of the three dimensional dynamics (i. e. displacements, velocities, accelerations) of the vocal folds. The next goal is the miniaturization of the LPS to allow clinical in-vivo analysis in humans. We anticipate new insight on dependencies between 3D dynamic behavior and the quality of the acoustic outcome for healthy and disordered phonation.

Kukoamine B promotes TLR4-independent lipopolysaccharide uptake in murine hepatocytes.

PubMed

Yang, Dong; Zheng, Xinchuan; Wang, Ning; Fan, Shijun; Yang, Yongjun; Lu, Yongling; Chen, Qian; Liu, Xin; Zheng, Jiang

2016-09-06

Free bacterial lipopolysaccharide (LPS) is generally removed from the bloodstream through hepatic uptake via TLR4, the LPS pattern recognition receptor, but mechanisms for internalization and clearance of conjugated LPS are less clear. Kukoamine B (KB) is a novel cationic alkaloid that interferes with LPS binding to TLR4. In this study, KB accelerated blood clearance of LPS. KB also enhanced LPS distribution in the hepatic tissues of C57 BL/6 mice, along with LPS uptake in primary hepatocytes and HepG2 cells. By contrast, KB inhibited LPS internalization in Kupffer and RAW 264.7 cells. Loss of TLR4 did not affect LPS uptake into KB-treated hepatocytes. We also detected selective upregulation of the asialoglycoprotein receptor (ASGPR) upon KB treatment, and ASGPR colocalized with KB in cultured hepatocytes. Molecular docking showed that KB bound to ASGPR in a manner similar to GalNAc, a known ASGPR agonist. GalNAc dose-dependently reduced KB internalization, suggesting it competes with KB for ASGPR binding, and ASGPR knockdown also impaired LPS uptake into hepatocytes. Finally, while KB enhanced LPS uptake, it was protective against LPS-induced inflammation and hepatocyte injury. Our study provides a new mechanism for conjugated LPS hepatic uptake induced by the LPS neutralizer KB and mediated by membrane ASGPR binding.

Analysis of adrenocortical secretory responses during acute an prolonged immune stimulation in inflammation-susceptible and -resistant rat strains.

PubMed

Andersson, I M; Lorentzen, J C; Ericsson-Dahlstrand, A

2000-11-01

Endogenous corticosterone secreted during immune challenge restricts the inflammatory process and genetic variations in this neuroendocrine-immune dialogue have been suggested to influence an individuals sensitivity to develop chronic inflammatory disorders. We have tested inflammation-susceptible Dark Agouti (DA) rats and resistant, MHC-identical, PVG.1AV1 rats for their abilities to secrete corticosterone in response to acute challenge with bacterial lipopolysaccharide (LPS) or a prolonged activation of the nonspecific immune system with arthritogenic yeast beta-glucan. Intravenous injection of LPS triggered equipotent secretion of corticosterone in both rat strains. Interestingly, peak concentrations of corticosterone did not differ significantly between the strains. Intradermal injection of beta-glucan caused severe, monophasic, polyarthritis in DA rats while PVG.1AV1 responded with significantly milder joint inflammation. Importantly, serial sampling of plasma from glucan-injected DA and PVG.1AV1 rats did not reveal elevated concentrations of plasma corticosterone at any time from days 1-30 postinjection compared to preinjection values, in spite of the ongoing inflammatory process. Interestingly, adrenalectomized, beta-glucan-challenged DA rats responded with an aggravated arthritic process, indicating an anti-inflammatory role for the basal levels of corticosterone that were detected in intact DA rats challenged with beta-glucan. Moreover, substitution with subcutaneous corticosterone-secreting pellets, yielding moderate stress-levels, significantly attenuated the arthritic response. In contrast, adrenalectomized and glucan-challenged PVG.1AV1 rats did not respond with an elevated arthritic response, suggesting that these rats contain the arthritic process via corticosterone-independent mechanisms. In conclusion, the hypothalamic-pituitary-adrenal axis in both rat strains exhibited strong activation after challenge with LPS. This contrasted to the basal corticosterone levels observed strains during a prolonged arthritic process. No correlation between ability to secrete corticosterone and susceptibility to inflammation could be demonstrated. Basal levels of endogenous corticosterone appeared to restrain inflammation in beta-glucan-challenged DA rats whereas resistance to inflammation in PVG.1AV1 rats may be mediated via corticosterone-independent mechanisms.

Particulate contamination spectrometer. Volume 1: Technical report

NASA Technical Reports Server (NTRS)

Schmitt, R. J.; Boyd, B. A.; Linford, R. M. F.

1975-01-01

A laser particulate spectrometer (LPS) system was developed to measure the size and speed distributions of particulate (dusts, aerosols, ice particles, etc.) contaminants. Detection of the particulates was achieved by means of light scattering and extinction effects using a single laser beam to cover a size range of 0.8 to 275 microns diameter and a speed range of 0.2 to 20 meter/second. The LPS system was designed to operate in the high vacuum environment of a space simulation chamber with cold shroud temperatures ranging from 77 to 300 K.

Induction of Pro-Inflammatory Response via Activated Macrophage-Mediated NF-κB and STAT3 Pathways in Gastric Cancer Cells.

PubMed

Zhou, Yujuan; Xia, Longzheng; Liu, Qiang; Wang, Heran; Lin, Jingguan; Oyang, Linda; Chen, Xiaoyan; Luo, Xia; Tan, Shiming; Tian, Yutong; Su, Min; Wang, Ying; Chen, Pan; Wu, Yang; Wang, Hui; Liao, Qianjin

2018-06-19

Chronic inflammation plays an important role in the initiation and progression of gastric cancer (GC). However, the role and relationship of activated macrophages with gastric mucous epithelium cells in initiating and maintaining the inflammatory process during gastric carcinogenesis remains unclear. The tumour associated macrophages (TAMs) density of gastric cancer was characterized by immunohistochemistry, and the relationship between macrophages and gastric epithelium cells was analysed using an in vitro culture system that imitates the inflammatory microenvironment. The production of pro-inflammatory cytokines was detected by enzyme-linked immunosorbent assay (ELISA) and quantitative real-time PCR (qRT-PCR). MTT assays, Western blotting, qRT-PCR, and luciferase reporter assays were used to detect the effects of cell proliferation, as well as the NF-κB and STAT3 signalling pathways. TAMs infiltrated with a high intensity in GC and were significantly correlated with histology grade (P = 0.012), metastasis (P = 0.001), TNM stage (P = 0.002), and poor prognosis in patients (PFS, P = 0.005; OS, P = 0.028). In addition, IL-6 and IL-8 were elevated in the serum of GC patients and significantly promoted the growth of GC. The exposure of BGC823 gastric cancer cells to a conditioned medium from LPS-treated D-THP-1 cells significantly induced the production of TNF-α, IL-6, IL-1β and IL-8 (P< 0.01). LPS and LPS-treated D-THP-1-conditioned media promoted gastric cancer cell proliferation and triggered the significant activation of NF-κB and STAT3 with a concomitant degradation of IκBα and an increase in JAK2 phosphorylation (P < 0.05). Moreover, gastric cancer cells markedly expressed cell membrane LPS receptors, such as TLR1, TLR4, TLR6, CD14 and MD2. TAMs are closely associated with the growth of GC and prognosis in GC patients. GC cells may directly sustain and amplify the local pro-inflammatory response upon encountering activated macrophages and LPS via NF-κB and STAT3 signalling pathways, thereby promoting tumour progression. © 2018 The Author(s). Published by S. Karger AG, Basel.

A Chemically Modified Curcumin (CMC 2.24) Inhibits Nuclear Factor κB Activation and Inflammatory Bone Loss in Murine Models of LPS-Induced Experimental Periodontitis and Diabetes-Associated Natural Periodontitis.

PubMed

Elburki, Muna S; Rossa, Carlos; Guimarães-Stabili, Morgana R; Lee, Hsi-Ming; Curylofo-Zotti, Fabiana A; Johnson, Francis; Golub, Lorne M

2017-08-01

The purpose of this study was to assess the effect of a novel chemically modified curcumin (CMC 2.24) on NF-κB and MAPK signaling and inflammatory cytokine production in two experimental models of periodontal disease in rats. Experimental model I: Periodontitis was induced by repeated injections of LPS into the gingiva (3×/week, 3 weeks); control rats received vehicle injections. CMC 2.24, or the vehicle, was administered by daily oral gavage for 4 weeks. Experimental model II: Diabetes was induced in adult male rats by streptozotocin injection; periodontal breakdown then results as a complication of uncontrolled hyperglycemia. Non-diabetic rats served as controls. CMC 2.24, or the vehicle, was administered by oral gavage daily for 3 weeks to the diabetics. Hemimaxillae and gingival tissues were harvested, and bone loss was assessed radiographically. Gingival tissues were pooled according to the experimental conditions and processed for the analysis of matrix metalloproteinases (MMPs) and bone-resorptive cytokines. Activation of p38 MAPK and NF-κB signaling pathways was assessed by western blot. Both LPS and diabetes induced an inflammatory process in the gingival tissues associated with excessive alveolar bone resorption and increased activation of p65 (NF-κB) and p38 MAPK. In both models, the administration of CMC 2.24 produced a marked reduction of inflammatory cytokines and MMPs in the gingival tissues, decreased bone loss, and decreased activation of p65 (NF-κB) and p38 MAPK. Inhibition of these cell signaling pathways by this novel tri-ketonic curcuminoid (natural curcumin is di-ketonic) may play a role in its therapeutic efficacy in locally and systemically associated periodontitis.

Fuzzy neural network technique for system state forecasting.

PubMed

Li, Dezhi; Wang, Wilson; Ismail, Fathy

2013-10-01

In many system state forecasting applications, the prediction is performed based on multiple datasets, each corresponding to a distinct system condition. The traditional methods dealing with multiple datasets (e.g., vector autoregressive moving average models and neural networks) have some shortcomings, such as limited modeling capability and opaque reasoning operations. To tackle these problems, a novel fuzzy neural network (FNN) is proposed in this paper to effectively extract information from multiple datasets, so as to improve forecasting accuracy. The proposed predictor consists of both autoregressive (AR) nodes modeling and nonlinear nodes modeling; AR models/nodes are used to capture the linear correlation of the datasets, and the nonlinear correlation of the datasets are modeled with nonlinear neuron nodes. A novel particle swarm technique [i.e., Laplace particle swarm (LPS) method] is proposed to facilitate parameters estimation of the predictor and improve modeling accuracy. The effectiveness of the developed FNN predictor and the associated LPS method is verified by a series of tests related to Mackey-Glass data forecast, exchange rate data prediction, and gear system prognosis. Test results show that the developed FNN predictor and the LPS method can capture the dynamics of multiple datasets effectively and track system characteristics accurately.

Use of a ground beef model to assess the effect of the lactoperoxidase system on the growth of Escherichia coli O157:H7, Listeria monocytogenes and Staphylococcus aureus in red meat.

PubMed

Kennedy, M; O'Rourke, A L; McLay, J; Simmonds, R

2000-06-15

The ability to preserve food in a state that is both appetising and nutritious is a basic requirement for health. Food poisoning represents a major source of illness and loss of productivity in many developed countries. Of particular concern in recent years are outbreaks of food poisoning associated with Escherichia coli O157:H7 or Listeria monocytogenes, many of which have been associated with the consumption of ground meat. Many of the chemicals presently licensed for use as food preservatives are increasingly being questioned with regard to their effects on humans, creating pressure on food suppliers to consider the use of 'natural' alternatives to these chemical agents. The potential use of one such agent, the lactoperoxidase system (LPS), for use in ground meat preparations is examined in this study. The degree of inhibition of growth of E. coli O157:H7, L. monocytogenes L45 and S. aureus R37 by LPS was examined in a broth system at 37 degrees C and in a ground beef system at 0, 6 and 12 degrees C. The degree of inhibition by LPS of natural populations of microorganisms present in ground beef obtained from eight retail outlets and incubated at room temperature was also examined. For each of the strains examined, sensitivity from most to least sensitive followed the order L. monocytogenes L45, S. aureus R37 and E. coli O157:H7. In each case the ability of LPS to inhibit growth was highly temperature dependent and maximal at a temperature permissive but not optimal for growth of the test strain. The numbers of bacteria detected in ground beef obtained from retail outlets varied considerably between the eight samples. In all cases, numbers of bacteria increased markedly in the uninhibited control over the 4 h incubation time and, with the exception of one faecal coliform count, growth of the microbial populations was strongly inhibited by the presence of LPS. It was concluded that LPS could potentially be applied to a considerably wider range of food products than those to which it is presently restricted.

Complex pattern of interaction between in utero hypoxia-ischemia and intra-amniotic inflammation disrupts brain development and motor function

PubMed Central

2014-01-01

Background Infants born preterm commonly suffer from a combination of hypoxia-ischemia (HI) and infectious perinatal inflammatory insults that lead to cerebral palsy, cognitive delay, behavioral issues and epilepsy. Using a novel rat model of combined late gestation HI and lipopolysaccharide (LPS)-induced inflammation, we tested our hypothesis that inflammation from HI and LPS differentially affects gliosis, white matter development and motor impairment during the first postnatal month. Methods Pregnant rats underwent laparotomy on embryonic day 18 and transient systemic HI (TSHI) and/or intra-amniotic LPS injection. Shams received laparotomy and anesthesia only. Pups were born at term. Immunohistochemistry with stereological estimates was performed to assess regional glial loads, and western blots were performed for protein expression. Erythropoietin ligand and receptor levels were quantified using quantitative PCR. Digigait analysis detected gait deficits. Statistical analysis was performed with one-way analysis of variance and post-hoc Bonferonni correction. Results Microglial and astroglial immunolabeling are elevated in TSHI + LPS fimbria at postnatal day 2 compared to sham (both P < 0.03). At postnatal day 15, myelin basic protein expression is reduced by 31% in TSHI + LPS pups compared to shams (P < 0.05). By postnatal day 28, white matter injury shifts from the acute injury pattern to a chronic injury pattern in TSHI pups only. Both myelin basic protein expression (P < 0.01) and the phosphoneurofilament/neurofilament ratio, a marker of axonal dysfunction, are reduced in postnatal day 28 TSHI pups (P < 0.001). Erythropoietin ligand to receptor ratios differ between brains exposed to TSHI and LPS. Gait analyses reveal that all groups (TSHI, LPS and TSHI + LPS) are ataxic with deficits in stride, paw placement, gait consistency and coordination (all P < 0.001). Conclusions Prenatal TSHI and TSHI + LPS lead to different patterns of injury with respect to myelination, axon integrity and gait deficits. Dual injury leads to acute alterations in glial response and cellular inflammation, while TSHI alone causes more prominent chronic white matter and axonal injury. Both injuries cause significant gait deficits. Further study will contribute to stratification of injury mechanisms in preterm infants, and guide the use of promising therapeutic interventions. PMID:25082427

Microarray and Pathway Analysis Reveal Distinct Mechanisms Underlying Cannabinoid-Mediated Modulation of LPS-Induced Activation of BV-2 Microglial Cells

PubMed Central

Juknat, Ana; Kozela, Ewa; Rimmerman, Neta; Levy, Rivka; Gao, Fuying; Coppola, Giovanni; Geschwind, Daniel; Vogel, Zvi

2013-01-01

Cannabinoids are known to exert immunosuppressive activities. However, the mechanisms which contribute to these effects are unknown. Using lipopolysaccharide (LPS) to activate BV-2 microglial cells, we examined how Δ9-tetrahydrocannabinol (THC), the major psychoactive component of marijuana, and cannabidiol (CBD) the non-psychoactive component, modulate the inflammatory response. Microarray analysis of genome-wide mRNA levels was performed using Illumina platform and the resulting expression patterns analyzed using the Ingenuity Pathway Analysis to identify functional subsets of genes, and the Ingenuity System Database to denote the gene networks regulated by CBD and THC. From the 5338 transcripts that were differentially expressed across treatments, 400 transcripts were found to be upregulated by LPS, 502 by CBD+LPS and 424 by THC+LPS, while 145 were downregulated by LPS, 297 by CBD+LPS and 149 by THC+LPS, by 2-fold or more (p≤0.005). Results clearly link the effects of CBD and THC to inflammatory signaling pathways and identify new cannabinoid targets in the MAPK pathway (Dusp1, Dusp8, Dusp2), cell cycle related (Cdkn2b, Gadd45a) as well as JAK/STAT regulatory molecules (Socs3, Cish, Stat1). The impact of CBD on LPS-stimulated gene expression was greater than that of THC. We attribute this difference to the fact that CBD highly upregulated several genes encoding negative regulators of both NFκB and AP-1 transcriptional activities, such as Trib3 and Dusp1 known to be modulated through Nrf2 activation. The CBD-specific expression profile reflected changes associated with oxidative stress and glutathione depletion via Trib3 and expression of ATF4 target genes. Furthermore, the CBD affected genes were shown to be controlled by nuclear factors usually involved in regulation of stress response and inflammation, mainly via Nrf2/Hmox1 axis and the Nrf2/ATF4-Trib3 pathway. These observations indicate that CBD, and less so THC, induce a cellular stress response and that this response underlies their high immunosuppressant activities. PMID:23637839

Sulforaphane suppresses LPS-induced or TPA-induced downregulation of PDCD4 in RAW 264.7 cells.

PubMed

Cho, Jong-Ho; Kim, Young-Woo; Keum, Young-Sam

2014-11-01

Sulforaphane is a natural chemopreventive isothiocyanate and abundantly found in various cruciferous vegetables. Although chemopreventive activity of sulforaphane is well documented, the detailed biochemical mechanism(s), underlying how it regulates the protein translation process to antagonize pro-inflammatory responses are largely unclear. In the present study, we show that lipopolysaccharide (LPS) or 12-O-tetradecanoylphorbol-13-acetate (TPA) treatment reduces cellular levels of PDCD4, and this event is mediated by affecting both transcription and proteolysis in RAW 264.7 cells. We show that LPS-mediated or TPA-mediated PDCD4 downregulation is catalyzed by the activation of intracellular Akt1 or S6K1 kinases and that sulforaphane suppresses LPS-induced or TPA-induced Akt1 or S6K1 activation, thereby resulting in the attenuation of PDCD4 downregulation in RAW 264.7 cells. We propose that sulforaphane suppression of PDCD4 downregulation serves as a novel molecular mechanism to control proliferation in response to pro-inflammatory signals. Copyright © 2014 John Wiley & Sons, Ltd.

Sulforaphane inhibits the engagement of LPS with TLR4/MD2 complex by preferential binding to Cys133 in MD2.

PubMed

Koo, Jung Eun; Park, Zee-Yong; Kim, Nam Doo; Lee, Joo Young

2013-05-10

Toll-like receptors (TLRs) are key pattern-recognition receptors that recognize invading pathogens and non-microbial endogenous molecules to induce innate and adaptive immune responses. Since activation of TLRs is deeply implicated in the pathological progress of autoimmune diseases, sepsis, metabolic diseases, and cancer, modulation of TLR activity is considered one of the most important therapeutic approaches. Lipopolysaccharide (LPS), an endotoxin of gram-negative bacteria, is a well-known agonist for TLR4 triggering inflammation and septic shock. LPS interacts with TLR4 through binding to a hydrophobic pocket in myeloid differentiation 2 (MD2), a co-receptor of TLR4. In this study, we showed that sulforaphane (SFN) interfered with the binding of LPS to MD2 as determined by in vitro binding assay and co-immunoprecipitation of MD2 and LPS in a cell system. The inhibitory effect of SFN on the interaction of LPS and MD2 was reversed by thiol supplementation with N-acetyl-L-cysteine or dithiothreitol showing that the inhibitory effect of SFN is dependent on its thiol-modifying activity. Indeed, micro LC-MS/MS analysis showed that SFN preferentially formed adducts with Cys133 in the hydrophobic pocket of MD2, but not with Cys95 and Cys105. Molecular modeling showed that SFN bound to Cys133 blocks the engagement of LPS and lipid IVa to hydrophobic pocket of MD2. Our results demonstrate that SFN interrupts LPS engagement to TLR4/MD2 complex by direct binding to Cys133 in MD2. Our data suggest a novel mechanism for the anti-inflammatory activity of SFN, and provide a novel target for the regulation of TLR4-mediated inflammatory and immune responses by phytochemicals. Copyright © 2013 Elsevier Inc. All rights reserved.

Influence of dietary conjugated linoleic acid isomers on early inflammatory responses in male broiler chickens.

PubMed

Takahashi, K; Kawamata, K; Akiba, Y; Iwata, T; Kasai, M

2002-03-01

1. The influence of dietary conjugated linoleic acid isomer (CLA, 0 and 10 g/kg) on the metabolic and physiological responses to immune stimulation induced by a single injection of Salmonella enteritidis lipopolysaccharide (LPS) or repeated injections of LPS and Sephadex G-50 was determined in male broiler chicks. 2. In experiment 1, 10-d-old chicks were fed on experimental diets for 14 d and half of the birds fed on each diet were injected intraperitoneally with LPS (1.5 mg/kg body weight). In experiment 2,7-d-old chicks were fed on experimental diets for 18 d. Immune stimulation was started at 19 d old and continued for 5 d. Half of the birds fed on each diet were injected intraperitoneally with 0.25 mg/kg body weight of LPS at 19, 21 and 23 d of age, and with 250 mg/kg body weight of Sephadex at 20 and 22 d of age to stimulate the immune system. 3. In experiment 1, giving CLA prevented an increase in blood heterophil to lymphocyte ratio 7 h after a single injection of LPS, and increases in plasma ceruloplasmin and alpha 1 acid glycoprotein (AGP) 24 h after the injection, but not 7 h after the injection. CLA also prevented a decrease in food intake for 24 h after LPS injection. 4. In experiment 2, the CLA diet partially prevented reductions in body weight gain and weight gain to feed intake ratio caused by repeated injections of LPS and Sephadex. Feeding CLA prevented increases in plasma ceruloplasmin and AGP at 24 d of age caused by repeated injections of LPS and Sephadex, but not at 20 d of age. 5. These results suggest that feeding CLA alleviates some undesirable metabolic and physiological changes induced by immunological stimulation in male broiler chicks.

Multiple lipopolysaccharide (LPS) injections alter interleukin 6 (IL-6), IL-7, IL-10 and IL-6 and IL-7 receptor mRNA in CNS and spleen.

PubMed

Szot, Patricia; Franklin, Allyn; Figlewicz, Dianne P; Beuca, Timothy Petru; Bullock, Kristin; Hansen, Kim; Banks, William A; Raskind, Murray A; Peskind, Elaine R

2017-07-04

Neuroinflammation is proposed to be an important component in the development of several central nervous system (CNS) disorders including depression, Alzheimer's disease, Parkinson's disease, and traumatic brain injury. However, exactly how neuroinflammation leads to, or contributes to, these central disorders is unclear. The objective of the study was to examine and compare the expression of mRNAs for interleukin-6 (IL-6), IL-7, IL-10 and the receptors for IL-6 (IL-6R) and IL-7 (IL-7R) using in situ hybridization in discrete brain regions and in the spleen after multiple injections of 3mg/kg lipopolysaccharide (LPS), a model of neuroinflammation. In the spleen, LPS significantly elevated IL-6 mRNA expression, then IL-10 mRNA, with no effect on IL-7 or IL-7R mRNA, while significantly decreasing IL-6R mRNA expression. In the CNS, LPS administration had the greatest effect on IL-6 and IL-6R mRNA. LPS increased IL-6 mRNA expression only in non-neuronal cells throughout the brain, but significantly elevated IL-6R mRNA in neuronal populations, where observed, except the cerebellum. LPS resulted in variable effects on IL-10 mRNA, and had no effect on IL-7 or IL-7R mRNA expression. These studies indicate that LPS-induced neuroinflammation has substantial but variable effects on the regional and cellular patterns of CNS IL-6, IL-7 and IL-10, and for IL-6R and IL-7R mRNA expression. It is apparent that administration of LPS can affect non-neuronal and neuronal cells in the brain. Further research is required to determine how CNS inflammatory changes associated with IL-6, IL-10 and IL-6R could in turn contribute to the development of CNS neurological disorders. Published by Elsevier Ltd.

Agmatine ameliorates lipopolysaccharide induced depressive-like behaviour in mice by targeting the underlying inflammatory and oxido-nitrosative mediators.

PubMed

Gawali, Nitin B; Bulani, Vipin D; Chowdhury, Amrita A; Deshpande, Padmini S; Nagmoti, Dnyaneshwar M; Juvekar, Archana R

2016-10-01

Experimental and clinical evidence indicates that pro-inflammatory cytokines, oxidative stress and brain-derived neurotrophic factor (BDNF) signalling mechanisms play a role in the pathophysiology of depression. Agmatine is a neurotransmitter and/or neuromodulator that has emerged as a potential agent to manage diverse central nervous system disorders. Agmatine has been shown to exert antidepressant-like effect. The present study investigated ability of agmatine to abolish the depressive-like behaviour induced by the administration of the lipopolysaccharide (LPS) in mice. Agmatine (20 and 40mg/kg) was administered daily for 7days, then the mice were challenged with saline or LPS (0.83mg/kg; i.p.) on the 7th day. After 24h of LPS administration we tested mice for depressive-like behaviour. LPS treated animals presented an increase in immobility time in the forced-swim test (FST), tail suspension test (TST) which was reversed by agmatine pre-treatment (20 and 40mg/kg). Oxidative/nitrosative stress evoked by LPS was ameliorated by both doses of agmatine in hippocampus (HC) and prefrontal cortex (PFC). Administration of LPS caused an increase in interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α), whereas BDNF was down regulated in the HC. Agmatine pre-treatment at 40mg/kg ameliorated LPS-induced neuroinflammation by attenuating brain IL-1β and TNF-α level. In addition, agmatine pre-treatment also up-regulated the BDNF level in the HC. The present study shows that pre-treatment of agmatine is able to abolish the behavioural responses in the FST and TST elicited by the LPS-induced model of depression that may depend on the inhibition of pro-inflammatory mediators, reduction of oxidative stress as well as activation neuroplasticity-related signalling in mice, suggesting that agmatine may constitute an monotherapy/adjuvant for the management of depression associated with inflammation. Copyright © 2016 Elsevier Inc. All rights reserved.

TNF{alpha} and IL-1{beta} are mediated by both TLR4 and Nod1 pathways in the cultured HAPI cells stimulated by LPS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Wenwen; Zheng, Xuexing; Department of Anesthesiology, University of Miami Miller School of Medicine, Miami, FL 33136

2012-04-20

Highlights: Black-Right-Pointing-Pointer LPS induces proinflammatory cytokine release in HAPI cells. Black-Right-Pointing-Pointer JNK pathway is dependent on TLR4 signaling to release cytokines. Black-Right-Pointing-Pointer NF-{kappa}B pathway is dependent on Nod1 signaling to release cytokines. -- Abstract: A growing body of evidence recently suggests that glial cell activation plays an important role in several neurodegenerative diseases and neuropathic pain. Microglia in the central nervous system express toll-like receptor 4 (TLR4) that is traditionally accepted as the primary receptor of lipopolysaccharide (LPS). LPS activates TLR4 signaling pathways to induce the production of proinflammatory molecules. In the present studies, we verified the LPS signaling pathwaysmore » using cultured highly aggressively proliferating immortalized (HAPI) microglial cells. We found that HAPI cells treated with LPS upregulated the expression of TLR4, phospho-JNK (pJNK) and phospho-NF-{kappa}B (pNF-{kappa}B), TNF{alpha} and IL-1{beta}. Silencing TLR4 with siRNA reduced the expression of pJNK, TNF{alpha} and IL-1{beta}, but not pNF-{kappa}B in the cells. Inhibition of JNK with SP600125 (a JNK inhibitor) decreased the expression of TNF{alpha} and IL-1{beta}. Unexpectedly, we found that inhibition of Nod1 with ML130 significantly reduced the expression of pNF-{kappa}B. Inhibition of NF-{kappa}B also reduced the expression of TNF{alpha} and IL-1{beta}. Nod1 ligand, DAP induced the upregulation of pNF-{kappa}B which was blocked by Nod1 inhibitor. These data indicate that LPS-induced pJNK is TLR4-dependent, and that pNF-{kappa}B is Nod1-dependent in HAPI cells treated with LPS. Either TLR4-JNK or Nod1-NF-{kappa}B pathways is involved in the expression of TNF{alpha} and IL-1{beta}.« less

Diet-induced bacterial immunogens in the gastrointestinal tract of dairy cows: Impacts on immunity and metabolism

PubMed Central

2011-01-01

Dairy cows are often fed high grain diets to meet the energy demand for high milk production or simply due to a lack of forages at times. As a result, ruminal acidosis, especially subacute ruminal acidosis (SARA), occurs frequently in practical dairy production. When SARA occurs, bacterial endotoxin (or lipopolysaccharide, LPS) is released in the rumen and the large intestine in a large amount. Many other bacterial immunogens may also be released in the digestive tract following feeding dairy cows diets containing high proportions of grain. LPS can be translocated into the bloodstream across the epithelium of the digestive tract, especially the lower tract, due to possible alterations of permeability and injuries of the epithelial tissue. As a result, the concentration of blood LPS increases. Immune responses are subsequently caused by circulating LPS, and the systemic effects include increases in concentrations of neutrophils and the acute phase proteins such as serum amyloid-A (SAA), haptoglobin (Hp), LPS binding protein (LBP), and C-reactive protein (CRP) in blood. Entry of LPS into blood can also result in metabolic alterations. Blood glucose and nonesterified fatty acid concentrations are enhanced accompanying an increase of blood LPS after increasing the amount of grain in the diet, which adversely affects feed intake of dairy cows. As the proportions of grain in the diet increase, patterns of plasma β-hydoxybutyric acid, cholesterol, and minerals (Ca, Fe, and Zn) are also perturbed. The bacterial immunogens can also lead to reduced supply of nutrients for synthesis of milk components and depressed functions of the epithelial cells in the mammary gland. The immune responses and metabolic alterations caused by circulating bacterial immunogens will exert an effect on milk production. It has been demonstrated that increases in concentrations of ruminal LPS and plasma acute phase proteins (CRP, SAA, and LBP) are associated with declines in milk fat content, milk fat yield, 3.5% fat-corrected milk yield, as well as milk energy efficiency. PMID:21824438

[Effects of Porphyromonas endodontalis lipopolysaccharides on the expression of matrix metalloproteinase-9 in mouse osteoblasts].

PubMed

Li, X L; Yu, Y Q; Qiu, L H; Yang, D; Wang, X M; Yu, J T

2017-08-09

Objective: To evaluate the effects of lipopolysaccharides (LPS) extracted from Porphyromonas endodontalis (Pe) on the expression of matrix metalloproteinase-9 (MMP-9) mRNA and protein as well as enzyme activity in MC3T3-E1 cells and the role of nuclear factor-κB (NF-κB) in the process, so as to investigate the expression of MMP-9 dependent signaling pathways in mouse osteoblasts induced by Pe LPS. Methods: The experiment was conducted in 3 sessions: MC3T3-E1 cells were treated with various concentrations of Pe LPS (0-20 mg/L) and 10 mg/L Pe LPS for different time intervals (0-48 h). The expression of MMP-9 mRNA and protein were detected by real-time reverse transcription-PCR (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), while the enzyme activity was detected by gelatin zymography method. The expression of MMP-9 mRNA was also detected in 10 mg/L Pe LPS treated MC3T3-El cells after pretreated with specific NF-κB inhibitor BAY 11-7082 for l h. Statistical analysis was performed using one-way ANOVA and Dunnett t test with SPSS 13.0 software package. Results: The levels of MMP-9 mRNA and protein increased significantly after the treatment with various concentrations of Pe LPS (0-20 mg/L), which indicated that Pe LPS induced osteoblasts to express MMP-9 in dose dependent manners. The expression of MMP-9 protein increased from (5 395±362) ng/L (blank control group) to (12 684±375) ng/L (20 mg/L group). Maximal induction of MMP-9 mRNA expression was found in the MC3T3-E1 cells treated with 10 mg/L Pe LPS for 24 h. The expression of MMP-9 mRNA in the 20 mg/L group was about 7 times than that in the blank control group. After 24 h, the expression of MMP-9 mRNA decreased. Maximal expression of MMP-9 protein was found in the MC3T3-E1 cells treated with 10 mg/L Pe LPS for 48 h ([35 055±2 346] ng/L) showing the highest enzyme activity. The mRNA of MMP-9 decreased significantly after pretreatment with 10 µmol/L BAY 11-7082 for 1 h. Conclusions: Pe LPS might induce the expression of MMP-9 in MC3T3-E1 cells through the signaling of NF-κB.

Improved immunogenicity of tetanus toxoid by Brucella abortus S19 LPS adjuvant.

PubMed

Mohammadi, Mohsen; Kianmehr, Zahra; Kaboudanian Ardestani, Sussan; Gharegozlou, Behnaz

2014-09-01

Adjuvants are used to increase the immunogenicity of new generation vaccines, especially those based on recombinant proteins. Despite immunostimulatory properties, the use of bacterial lipopolysaccharide (LPS) as an adjuvant has been hampered due to its toxicity and pyrogenicity. Brucella abortus LPS is less toxic and has no pyrogenic properties compared to LPS from other gram negative bacteria. To evaluate the adjuvant effect of B. abortus (vaccine strain, S19) LPS for tetanus toxoid antigen (TT) and to investigate the protective effect of different tetanus vaccine preparations. LPS was extracted and purified from B. abortus S19 and KDO, glycan, phosphate content, and protein contamination were measured. Adipic acid dihydrazide (ADH) was used as a linker for conjugation of TT to LPS. Different amounts of B. abortus LPS, TT, TT conjugated with LPS, and TT mixed with LPS or complete Freund's adjuvant (CFA) were injected into mice and antibody production against TT was measured. The protective effect of induced antibodies was determined by LD50. Immunization of mice with TT+LPS produced the highest anti-TT antibody titer in comparison to the group immunized with TT without any adjuvant or the groups immunized with TT-LPS or TT+CFA. Tetanus toxid-S19 LPS also produced a 100% protective effect against TT in immunized mice. These data indicate that B. abortus LPS enhances the immune responses to TT and suggest the possible use of B. abortus LPS as an adjuvant in vaccine preparations.

Adenosine-dependent phrenic motor facilitation is inflammation resistant

PubMed Central

Agosto-Marlin, Ibis M.; Nichols, Nicole L.

2016-01-01

Phrenic motor facilitation (pMF), a form of respiratory plasticity, can be elicited by acute intermittent hypoxia (i.e., phrenic long-term facilitation, pLTF) or direct application of drugs to the cervical spinal cord. Moderate acute intermittent hypoxia (mAIH; 3 × 5-min episodes of 35–50 mmHg arterial Po2, 5-min normoxic intervals) induces pLTF by a serotonin-dependent mechanism; mAIH-induced pLTF is abolished by mild systemic inflammation induced by a low dose of lipopolysaccharide (LPS; 100 μg/kg ip). In contrast, severe acute intermittent hypoxia (sAIH; 3 × 5-min episodes of 25–30 mmHg arterial Po2, 5-min normoxic intervals) elicits pLTF by a distinct, adenosine-dependent mechanism. Since it is not known if systemic LPS blocks the mechanism giving rise to sAIH-induced pLTF, we tested the hypothesis that sAIH-induced pLTF and adenosine 2A (A2A) receptor-induced pMF are insensitive to mild systemic inflammation elicited by the same low dose of LPS. In agreement with our hypothesis, neither sAIH-induced pLTF nor cervical intrathecal A2A receptor agonist (CGS-21680; 200 μM, 10 μl × 3)-induced pMF were affected 24 h post-LPS. Pretreatment with intrathecal A2A receptor antagonist injections (MSX-3; 10 μM, 12 μl) blocked sAIH-induced pLTF 24 h post LPS, confirming that pLTF was adenosine dependent. Our results give insights concerning the differential impact of systemic inflammation and the functional significance of multiple cascades capable of giving rise to phrenic motor plasticity. The relative resistance of adenosine-dependent pMF to inflammation suggests that it provides a “backup” system in animals lacking serotonin-dependent pMF due to ongoing inflammation associated with systemic infections and/or neural injury. NEW & NOTEWORTHY This study gives novel insights concerning how a mild systemic inflammation impacts phrenic motor plasticity (pMF), particularly adenosine-dependent pMF. We suggest that since this adenosine-dependent pathway is insensitive to systemic inflammation, it represents an alternative or “backup” mechanism of pMF when other mechanisms are suppressed. PMID:27927784

Dedifferentiated liposarcoma with "homologous" lipoblastic (pleomorphic liposarcoma-like) differentiation: clinicopathologic and molecular analysis of a series suggesting revised diagnostic criteria.

PubMed

Mariño-Enríquez, Adrián; Fletcher, Christopher D M; Dal Cin, Paola; Hornick, Jason L

2010-08-01

Dedifferentiated liposarcoma (LPS) is a malignant adipocytic neoplasm defined as the transition from well-differentiated LPS to a nonlipogenic sarcoma. Heterologous differentiation is seen in 5% to 10% of dedifferentiated LPS, usually with myogenic or osteo/chondrosarcomatous elements. Adipocytic differentiation in the dedifferentiated component is incompatible with the current definition of dedifferentiated LPS. Pleomorphic LPS is a high-grade sarcoma containing lipoblasts. At least in areas, pleomorphic LPS can be indistinguishable from dedifferentiated LPS, except for the presence of lipoblasts in pleomorphic LPS and well-differentiated LPS areas in dedifferentiated LPS. We evaluated 12 unusual liposarcomas: 11 cases with pleomorphic LPS-like morphology affecting patients with concomitant or previous well-differentiated/dedifferentiated LPS, and 1 case resembling inflammatory "MFH" with scattered lipoblasts. Clinical and histologic features were reviewed. Immunohistochemistry for MDM2 and CDK4 was carried out. Amplification of 12q13 to q15 was studied by FISH analysis of the HMGA2 locus. The tumors arose in the retroperitoneum (7), proximal lower extremity (3), chest wall (1), and neck (1) of 9 males and 3 females (median age 66 y; range 49 to 76). Size ranged from 9 to 32 cm (median 23 cm). In 3 cases, there was an abrupt transition between well-differentiated LPS and sheets of pleomorphic lipoblasts, indistinguishable from pleomorphic LPS. Four cases consisted of otherwise typical dedifferentiated LPS (with adjacent well-differentiated LPS), except for the presence of lipoblasts in the high-grade component. One case contained both nonlipogenic spindle cell areas and an inflammatory "MFH"-like component with numerous admixed lipoblasts. Four cases were composed exclusively of pleomorphic LPS-like areas developing in 1 of the recurrences or metastases of a prior typical dedifferentiated LPS. Two cases also showed heterologous smooth muscle differentiation. MDM2 and CDK4 were positive in both the dedifferentiated LPS and pleomorphic LPS-like components in 12/12 and 11/12 cases, respectively. FISH analysis showed high-level amplification of 12q14.3 in all 8 cases successfully tested. Karyotypes were available for 3 cases and showed ring and giant marker chromosomes. Follow-up, available for 11 patients, ranged from 19 to 196 months (median 36 mo). Seven patients developed local recurrences (multiple in 3), and 3 developed lung metastases. Thus far, 5 patients have died of disease, 3 are alive with recurrent or metastatic disease, and 3 are alive with no evidence of disease. We conclude that dedifferentiated LPS can show lipoblastic differentiation in the high-grade component, resulting in areas indistinguishable from pleomorphic LPS. The available clinical and molecular data support the notion of "homologous" lipoblastic differentiation in dedifferentiated LPS, rather than mixed-type LPS.

Characteristics of thermoregulatory and febrile responses in mice deficient in prostaglandin EP1 and EP3 receptors

PubMed Central

Oka, Takakazu; Oka, Kae; Kobayashi, Takuya; Sugimoto, Yukihiko; Ichikawa, Atsushi; Ushikubi, Fumitaka; Narumiya, Shuh; Saper, Clifford B

2003-01-01

Previous studies have disagreed about whether prostaglandin EP1 or EP3 receptors are critical for producing febrile responses. We therefore injected lipopolysaccharide (LPS) at a variety doses (1 μg kg−1−1 mg kg−1) intraperitoneally (I.P.) into wild-type (WT) mice and mice lacking the EP1 or the EP3 receptors and measured changes in core temperature (Tc) by using telemetry. In WT mice, I.P. injection of LPS at 10 μg kg−1 increased Tc about 1 °C, peaking 2 h after injection. At 100 μg kg−1, LPS increased Tc, peaking 5–8 h after injection. LPS at 1 mg kg−1 decreased Tc, reaching a nadir at 5–8 h after injection. In EP1 receptor knockout (KO) mice injected with 10 μg kg−1 LPS, only the initial (< 40 min) increase in Tc was lacking; with 100 μg kg−1 LPS the mice showed no febrile response. In EP3 receptor KO mice, LPS decreased Tc in a dose- and time-dependent manner. Furthermore, in EP3 receptor KO mice subcutaneous injection of turpentine did not induce fever. Both EP1 and EP3 receptor KO mice showed a normal circadian cycle of Tc and brief hyperthermia following psychological stress (cage-exchange stress and buddy-removal stress). The present study suggests that both the EP1 and the EP3 receptors play a role in fever induced by systemic inflammation but neither EP receptor is involved in the circadian rise in Tc or psychological stress-induced hyperthermia in mice. PMID:12837930

Time-dependent effect of clonidine on microvascular permeability during endotoxemia.

PubMed

Schmidt, Karsten; Hernekamp, Jochen Frederick; Philipsenburg, Christoph; Zivkovic, Aleksandar R; Brenner, Thorsten; Hofer, Stefan

2015-09-01

Endothelial leakage with accompanying tissue edema and increased leukocyte adhesion are characteristics of the vascular inflammatory response. Tissue edema formation is a key mechanism in sepsis pathophysiology contributing to impaired tissue oxygenation and the development of shock. Sepsis mortality is directly associated with the severity of these microcirculatory alterations. Dysfunction of the sympathetic nervous system can have deleterious effects in generalized inflammation. This study evaluated the effect of the adrenergic alpha 2 agonist clonidine on microvascular permeability and leukocyte adhesion during endotoxemia. Macromolecular leakage, leukocyte adhesion, and venular wall shear rate were examined in mesenteric postcapillary venules of rats by using intravital microscopy (IVM). Lipopolysaccharide (LPS) (4mg/kg/h) or equivalent volumes of saline were continuously infused following baseline IVM at 0min. IVM was repeated after 60 and 120min in endotoxemic and nonendotoxemic animals. Clonidine (10μg/kg) was applied as an i.v. bolus. Animals received either (i) saline alone, (ii) clonidine alone, (iii) clonidine 45min prior to LPS, (iv) clonidine 10min prior to LPS, (v) clonidine 30min after LPS, or (vi) LPS alone. Due to nonparametric data distribution, Wilcoxon test and Dunn's multiple comparisons test were used for data analysis. Data were considered statistically significant at p<0.05. LPS significantly increased microvascular permeability and leukocyte adhesion and decreased venular wall shear rate. Clonidine significantly reduced microvascular permeability when applied 45min before or 30min after LPS administration. Leukocyte adhesion and venular wall shear rate were not affected by clonidine during endotoxemia. Clonidine reduces microvascular permeability in endotoxemic animals in a time-dependent manner. Adrenergic alpha 2 agonists might prove beneficial in stabilizing capillary leakage during inflammation. Copyright © 2015 Elsevier Inc. All rights reserved.

Losartan attenuated lipopolysaccharide-induced lung injury by suppression of lectin-like oxidized low-density lipoprotein receptor-1.

PubMed

Deng, Wang; Deng, Yue; Deng, Jia; Wang, Dao-Xin; Zhang, Ting

2015-01-01

Recent study has shown that renin-angiotensin system plays an important role in the development of acute lung injury (ALI) with high level of angiotensin II (AngII) generated form AngI catalyzed by angiotensin-converting enzyme. AngII plays a major effect mainly through AT1 receptor. Therefore, we speculate inhibition of AT1 receptor may possibly attenuate the lung injury. Losartan, an antagonist of AT1 receptor for angiotensin II, attenuated lung injury by alleviation of the inflammation response in ALI, but the mechanism of losartan in ALI still remains unclear. Thirty male Sprague-Dawley rats were randomly divided into Control group, ALI group (LPS), and Losartan group (LPS + Losartan). Bronchoalveolar lavage fluid (BALF) and lung tissue were obtained for analysis. The expressions of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), intercellular adhesion molecule-1 (ICAM-1) and caspase-3 were detected by reverse transcriptase polymerase chain reaction (RT-PCR) and western blotting. In ALI group, TNF-α and protein level in BALF, MPO activity in lung tissue, pulmonary edema and lung injury were significantly increased. Losartan significantly reduced LPS-induced increase in TNF-α and protein level in BALF, MPO activity, pulmonary edema and lung injury in LPS-induced lung injury. The mRNA and protein expression levels of LOX-1 were significantly decreased with the administration of losartan in LPS-induced lung injury. Also, losartan blocked the protein levels of caspase-3 and ICAM-1 mediated by LOX-1 in LPS-induced lung injury. Losartan attenuated lung injury by alleviation of the inflammation and cell apoptosis by inhibition of LOX-1 in LPS-induced lung injury.

Losartan attenuated lipopolysaccharide-induced lung injury by suppression of lectin-like oxidized low-density lipoprotein receptor-1

PubMed Central

Deng, Wang; Deng, Yue; Deng, Jia; Wang, Dao-Xin; Zhang, Ting

2015-01-01

Introduction: Recent study has shown that renin-angiotensin system plays an important role in the development of acute lung injury (ALI) with high level of angiotensin II (AngII) generated form AngI catalyzed by angiotensin-converting enzyme. AngII plays a major effect mainly through AT1 receptor. Therefore, we speculate inhibition of AT1 receptor may possibly attenuate the lung injury. Losartan, an antagonist of AT1 receptor for angiotensin II, attenuated lung injury by alleviation of the inflammation response in ALI, but the mechanism of losartan in ALI still remains unclear. Methods: Thirty male Sprague-Dawley rats were randomly divided into Control group, ALI group (LPS), and Losartan group (LPS + Losartan). Bronchoalveolar lavage fluid (BALF) and lung tissue were obtained for analysis. The expressions of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), intercellular adhesion molecule-1 (ICAM-1) and caspase-3 were detected by reverse transcriptase polymerase chain reaction (RT-PCR) and western blotting. Results: In ALI group, TNF-α and protein level in BALF, MPO activity in lung tissue, pulmonary edema and lung injury were significantly increased. Losartan significantly reduced LPS-induced increase in TNF-α and protein level in BALF, MPO activity, pulmonary edema and lung injury in LPS-induced lung injury. The mRNA and protein expression levels of LOX-1 were significantly decreased with the administration of losartan in LPS-induced lung injury. Also, losartan blocked the protein levels of caspase-3 and ICAM-1 mediated by LOX-1 in LPS-induced lung injury. Conclusions: Losartan attenuated lung injury by alleviation of the inflammation and cell apoptosis by inhibition of LOX-1 in LPS-induced lung injury. PMID:26884836

The Lipopolysaccharide of Brucella abortus BvrS/BvrR Mutants Contains Lipid A Modifications and Has Higher Affinity for Bactericidal Cationic Peptides

PubMed Central

Manterola, Lorea; Moriyón, Ignacio; Moreno, Edgardo; Sola-Landa, Alberto; Weiss, David S.; Koch, Michel H. J.; Howe, Jörg; Brandenburg, Klaus; López-Goñi, Ignacio

2005-01-01

The two-component BvrS/BvrR system is essential for Brucella abortus virulence. It was shown previously that its dysfunction abrogates expression of some major outer membrane proteins and increases bactericidal peptide sensitivity. Here, we report that BvrS/BvrR mutants have increased surface hydrophobicity and susceptibility to killing by nonimmune serum. The bvrS and bvrR mutant lipopolysaccharides (LPSs) bound more polymyxin B, chimeras constructed with bvrS mutant cells and parental LPS showed augmented polymyxin B resistance, and, conversely, parental cells and bvrS mutant LPS chimeras were more sensitive and displayed polymyxin B-characteristic outer membrane lesions, implicating LPS as being responsible for the phenotype of the BvrS/BvrR mutants. No qualitative or quantitative changes were detected in other envelope and outer membrane components examined: periplasmic β(1-2) glucans, native hapten polysaccharide, and phospholipids. The LPS of the mutants was similar to parental LPS in O-polysaccharide polymerization and fine structure but showed both increased underacylated lipid A species and higher acyl-chain fluidity that correlated with polymyxin B binding. These lipid A changes did not alter LPS cytokine induction, showing that in contrast to other gram-negative pathogens, recognition by innate immune receptors is not decreased by these changes in LPS structure. Transcription of Brucella genes required for incorporating long acyl chains into lipid A (acpXL and lpxXL) or implicated in lipid A acylation control (bacA) was not affected. We propose that in Brucella the outer membrane homeostasis depends on the functioning of BvrS/BvrR. Accordingly, disruption of BvrS/BvrR damages the outer membrane, thus contributing to the severe attenuation manifested by bvrS and bvrR mutants. PMID:16077108

The effects of D3R on TLR4 signaling involved in the regulation of METH-mediated mast cells activation.

PubMed

Xue, Li; Geng, Yan; Li, Ming; Jin, Yao-Feng; Ren, Hui-Xun; Li, Xia; Wu, Feng; Wang, Biao; Cheng, Wei-Ying; Chen, Teng; Chen, Yan-Jiong

2016-07-01

Accumulating studies have revealed that the dopamine D3 receptor (D3R) plays an important role in methamphetamine (METH) addiction. However, the action of D3R on METH-mediated immune response and the underlying mechanism remain unclear. Mast cells (MCs) are currently identified as effector cells in many processes of immune responses, and MC activation is induced by various stimuli such as lipopolysaccharide (LPS). Moreover, CD117 and FcεRI are known as MC markers due to their specific expression in MCs. To investigate the effects of D3R on METH-mediated alteration of LPS-induced MCs activation and the underlying mechanism, in this study, we examined the expression of CD117 and FcεRI in the intestines of wild-type (D3R(+/+)) and D3R-deficient (D3R(-/-)) mice. We also measured the production of MC-derived cytokines, including TNF-α, IL-6, IL-4, IL-13 and CCL-5, in the bone marrow-derived mast cells (BMMCs) of WT and D3R(-/-) mice. Furthermore, we explored the effects of D3R on METH-mediated TLR4 and downstream MAPK and NF-κB signaling induced by LPS in mouse BMMCs. We found that METH suppressed MC activation induced by LPS in the intestines of D3R(+/)mice. In contrast, LPS-induced MC activation was less affected by METH in D3R(-/-) mice. Furthermore, METH altered LPS-induced cytokine production in BMMCs of D3R(+/+) mice but not D3R(-/-) mice. D3R was also involved in METH-mediated modulation of LPS-induced expression of TLR4 and downstream MAPK and NF-κB signaling molecules in mouse BMMCs. Taken together, our findings demonstrate that the effect of D3R on TLR4 signaling may be implicated in the regulation of METH-mediated MCs activation induced by LPS. Copyright © 2016 Elsevier B.V. All rights reserved.

Effects of interleukin-1beta and lipopolysaccharide on behavior of mice in the elevated plus-maze and open field tests.

PubMed

Swiergiel, Artur H; Dunn, Adrian J

2007-04-01

It has been postulated that infections, inflammatory processes and resulting cytokines may be causative factors in emotional disorders, including depression and anxiety. Support for this possibility has been sought in studies of animal behavior following administration of interleukin-1 (IL-1) and lipopolysaccharide (LPS). However, such treatments induce a variety of behavioral responses, collectively known as sickness behavior, some of which could affect the performance in tests used to assess anxiety and depression. Thus the effects of peripheral administration of IL-1beta and LPS on the behavior of mice were studied in the elevated plus-maze (EPM) and the open field (OF). Mouse IL-1beta (30, 100, 300, and 1000 ng) was injected intraperitoneally 30 or 60 min, and LPS (0.5, 1 and 5 microg) 120 min before the tests. IL-1beta and LPS induced dose-dependent decreases in open arm entries and the time spent on the open arms in the EPM, effects considered to reflect anxiety-like behavior. However, entries to all arms were also reduced in a dose-dependent manner, indicating a decrease in general activity. In the OF, IL-1beta and LPS decreased the number of line crossings in the center of the field, that can also be considered to reflect anxiety-like behavior. However, this effect was accompanied by a similar decrease in line crossings in the periphery, as well as in rears and climbs. Thus the doses of IL-1beta and LPS necessary to induce these effects also decreased locomotor activity in the EPM and OF. Therefore, the behavioral responses induced by IL-1beta and LPS in the EPM and the OF considered to reflect anxiety must be interpreted in the light of this reduction in overall activity. Thus the results do not provide unequivocal support for the suggestion that LPS or IL-1 mediate anxiety. Nevertheless, because infections, endotoxins, and the ensuing cytokines cause alterations in CNS norepinephrine and serotonin, they may contribute to emotionality, and perhaps to anxiety.

Production of nitric oxide by peripheral blood mononuclear cells from the Florida manatee, Trichechus manatus latirostris.

PubMed

Walsh, Catherine J; Stuckey, Joyce E; Cox, Heather; Smith, Brett; Funke, Christina; Stott, Jeff; Colle, Clarence; Gaspard, Joseph; Manire, Charles A

2007-08-15

Florida manatees (Trichechus manatus latirostris) are exposed to many conditions in their habitat that may adversely impact health and impair immune function in this endangered species. In an effort to increase the current knowledge base regarding the manatee immune system, the production of an important reactive nitrogen intermediate, nitric oxide (NO), by manatee peripheral blood mononuclear cells (PBMC) was investigated. PBMC from healthy captive manatees were stimulated with LPS, IFN-gamma, or TNF-alpha, either alone or in various combinations, with NO production assessed after 24, 48, 72, and 96 h of culture. NO production in response to LPS stimulation was significantly greater after 48, 72, or 96 h of culture compared to NO production after 24h of culture. A specific inhibitor of inducible nitric oxide synthase (iNOS), L-NIL (L-N(6)-(1-iminoethyl)lysine), significantly decreased NO production by LPS-stimulated manatee PBMC. Manatee specific oligonucleotide primers for iNOS were designed to measure expression of relative amounts of mRNA in LPS-stimulated manatee PBMC from captive manatees. NO production by PBMC from manatees exposed to red tide toxins was analyzed, with significantly greater NO production by both unstimulated and LPS stimulated PBMC from red tide exposed compared with healthy captive or cold-stress manatees. Free-ranging manatees produced significantly lower amounts of nitric oxide compared to either captive or red tide rescued manatees. Results presented in this paper contribute to the current understanding of manatee immune function and represent the first report of nitric oxide production in the immune system of a marine mammal.

Building sustainable organizational capacity to deliver HIV programs in resource-constrained settings: stakeholder perspectives.

PubMed

Sharma, Anjali; Chiliade, Philippe; Michael Reyes, E; Thomas, Kate K; Collens, Stephen R; Rafael Morales, José

2013-12-13

In 2008, the US government mandated that HIV/AIDS care and treatment programs funded by the US President's Emergency Plan for AIDS Relief (PEPFAR) should shift from US-based international partners (IPs) to registered locally owned organizations (local partners, or LPs). The US Health Resources and Services Administration (HRSA) developed the Clinical Assessment for Systems Strengthening (ClASS) framework for technical assistance in resource-constrained settings. The ClASS framework involves all stakeholders in the identification of LPs' strengths and needs for technical assistance. This article examines the role of ClASS in building capacity of LPs that can endure and adapt to changing financial and policy environments. All stakeholders (n=68) in Kenya, Zambia, and Nigeria who had participated in the ClASS from LPs and IPs, the US Centers for Disease Control and Prevention (CDC), and, in Nigeria, HIV/AIDS treatment facilities (TFs) were interviewed individually or in groups (n=42) using an open-ended interview guide. Thematic analysis revealed stakeholder perspectives on ClASS-initiated changes and their sustainability. Local organizations were motivated to make changes in internal operations with the ClASS approach, PEPFAR's competitive funding climate, organizational goals, and desired patient health outcomes. Local organizations drew on internal resources and, if needed, technical assistance from IPs. Reportedly, ClASS-initiated changes and remedial action plans made LPs more competitive for PEPFAR funding. LPs also attributed their successful funding applications to their preexisting systems and reputation. Bureaucracy, complex and competing tasks, and staff attrition impeded progress toward the desired changes. Although CDC continues to provide technical assistance through IPs, declining PEPFAR funds threaten the consolidation of gains, smooth program transition, and continuity of treatment services. The well-timed adaptation and implementation of ClASS successfully engaged stakeholders who committed their own resources toward strengthening organizational capacity. The sustainability of built capacity depends on continued investment in leadership, staff retention, and quality improvement.

LPS receptor CD14 participates in release of TNF-alpha in RAW 264.7 and peritoneal cells but not in kupffer cells.

PubMed

Lichtman, S N; Wang, J; Lemasters, J J

1998-07-01

Lipopolysaccharide (LPS) is a bacterial polymer that stimulates macrophages to release tumor necrosis factor-alpha (TNF-alpha). In macrophages (RAW 264.7 and peritoneal cells), LPS binds to the CD14 surface receptor as the first step toward signaling. Liver macrophages, Kupffer cells, are the most numerous fixed-tissue macrophage in the body. The presence of CD14 on Kupffer cells and its role in LPS stimulation of TNF-alpha were examined. TNF-alpha release by Kupffer cells after LPS stimulation was the same in the presence and absence of serum. RAW 264.7 and peritoneal cells, which utilize the CD14 receptor, released significantly less TNF-alpha after LPS stimulation in the absence of serum because of the absence of LPS-binding protein. Phosphatidylinositol-phospholipase C treatment, which cleaves the CD14 receptor, decreased LPS-stimulated TNF-alpha release by RAW 264.7 cells but not by Kupffer cells. Deacylated LPS (dLPS) competes with LPS at the CD14 receptor when incubated in a ratio of 100:1 (dLPS/LPS). Such competition blocked LPS-stimulated TNF-alpha release from RAW 264.7 cells but not from Kupffer cells. Western and fluorescence-activated cell sorter analysis directly demonstrated the presence of CD14 on RAW 264.7 cells and murine peritoneal cells but showed only minimal amounts of CD14 in murine Kupffer cells. LPS stimulation did not increase the amount of CD14 detectable on mouse Kupffer cells. CD14 expression is very low in Kupffer cells, and LPS-stimulated TNF-alpha release is independent of CD14 in these cells.

Assessment of the synergic effect of immunomodulation on nerve repair using multiparametric magnetic resonance imaging.

PubMed

Zheng, Chu-Shan; Zhang, Xiang; Chen, Yue-Yao; Zhang, Fang; Duan, Xiao-Hui; Chen, Mei-Wei; Lu, Lie-Jing; Shen, Jun

2018-01-01

The immune system plays a pivotal role in nerve injury. The aim of this study was to determine the role of multiparametric magnetic resonance imaging (MRI) in evaluation of the synergic effect of immunomodulation on nerve regeneration in neurotmesis. Rats with sciatic nerve neurotmesis and surgical repair underwent serial multiparametric MR examinations over an 8-week period after subepineurial microinjection of lipopolysaccharide (LPS) and subsequent subcutaneous injection of FK506 or subepineurial microinjection of LPS or phosphate-buffered saline (PBS) alone. Nerves treated with immunomodulation showed more prominent regeneration than those treated with LPS or PBS alone and more rapid restoration toward normal T2, fractional anisotropy (FA), and radial diffusivity (RD) values than nerves injected with LPS or PBS. Nerves treated with immunomodulation exert synergic beneficial effects on nerve regeneration that can be predicted by T2 measurements and FA and RD values. Muscle Nerve 57: E38-E45, 2018. © 2017 Wiley Periodicals, Inc.

The phosphoproteome of toll-like receptor-activated macrophages

PubMed Central

Weintz, Gabriele; Olsen, Jesper V; Frühauf, Katja; Niedzielska, Magdalena; Amit, Ido; Jantsch, Jonathan; Mages, Jörg; Frech, Cornelie; Dölken, Lars; Mann, Matthias; Lang, Roland

2010-01-01

Recognition of microbial danger signals by toll-like receptors (TLR) causes re-programming of macrophages. To investigate kinase cascades triggered by the TLR4 ligand lipopolysaccharide (LPS) on systems level, we performed a global, quantitative and kinetic analysis of the phosphoproteome of primary macrophages using stable isotope labelling with amino acids in cell culture, phosphopeptide enrichment and high-resolution mass spectrometry. In parallel, nascent RNA was profiled to link transcription factor (TF) phosphorylation to TLR4-induced transcriptional activation. We reproducibly identified 1850 phosphoproteins with 6956 phosphorylation sites, two thirds of which were not reported earlier. LPS caused major dynamic changes in the phosphoproteome (24% up-regulation and 9% down-regulation). Functional bioinformatic analyses confirmed canonical players of the TLR pathway and highlighted other signalling modules (e.g. mTOR, ATM/ATR kinases) and the cytoskeleton as hotspots of LPS-regulated phosphorylation. Finally, weaving together phosphoproteome and nascent transcriptome data by in silico promoter analysis, we implicated several phosphorylated TFs in primary LPS-controlled gene expression. PMID:20531401

Mitochondrial anti-oxidant protects IEX-1 deficient mice from organ damage during endotoxemia

PubMed Central

Ramsey, Haley; Wu, Mei X.

2015-01-01

Sepsis, a leading cause of mortality in intensive care units worldwide, is often a result of overactive and systemic inflammation following serious infections. We found that mice lacking immediate early responsive gene X-1 (IEX-1) were prone to lipopolysaccharide (LPS) -induced endotoxemia. A nonlethal dose of LPS provoked numerous aberrations in IEX-1 knockout (KO) mice including pancytopenia, increased serum aspartate aminotransferase (AST), and lung neutrophilia, concurrent with liver and kidney damage, followed by death. Given these results, in conjunction with a proven role for IEX-1 in the regulation of reactive oxygen species (ROS) homeostasis during stress, we pre-treated IEX-1 KO mice with Mitoquinone (MitoQ), a mitochondrion-based antioxidant prior to LPS injection. The treatment significantly reduced ROS formation in circulatory cells and protected against pancytopenia and multiple organ failure, drastically increasing the survival rate of IEX-1 KO mice challenged by this low dose of LPS. This study confirms significant contribution of mitochondrial ROS to the etiology of sepsis. PMID:25466275

Effects of prenatal lipopolysaccharide exposure on reproductive activities and serum concentrations of pituitary-gonadal hormones in mice offspring.

PubMed

Solati, Jalal; Hajikhani, Ramin; Rashidieh, Behnam; Jalilian, Mahshid Fatipour

2012-04-01

Maternal infection during pregnancy is a risk factor for some behavioral problems with neurodevelopmental origin. This study aimed to evaluate the effects of exposure of pregnant mice to the bacterial lipopolysaccharide (LPS) on sexual behaviour and serum level of pituitary-gonadal hormones of offspring in adulthood. In this Expremental study, pregnant NMRI mice (n=7/group) were treated with intra-peritoneal administration of LPS (1, 5 and 10 µg/kg) at day 10 of gestation. Induction of the pro-inflammatory cytokines, Tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β) and interleukin-6 (IL-6) were measured in maternal serum 2 hours following the maternal LPS challenge. Behavior in the adult male offspring reproductive activity was investigated using receptive female mice. Concentrations of testosterone, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in adult offspring serum were measured using the enzyme-linked immunosorbent assay (ELISA) method (at postnatal day 60, n=10/group). One-way ANOVA showed that LPS administration induces a significant increase in TNF-α, IL-1β and IL-6 levels of maternal serum. Prenatal LPS exposure reduces sexual behavior and serum concentration of LH and testosterone in adult male offspring. The overall results suggest that prenatal exposure to LPS increases pro- inflammatory cytokine levels, affects development of neuroendocrine systems and results in the inhibition of reproductive behaviors and reactivity of hypothalamic-pituitary-gonadal (HPG) axis in adult male offspring.

Role of SIRT1 in heat stress- and lipopolysaccharide-induced immune and defense gene expression in human dental pulp cells.

PubMed

Lee, Sang-Im; Min, Kyung-San; Bae, Won-Jung; Lee, Young-Man; Lee, So-Youn; Lee, Eui-Suk; Kim, Eun-Cheol

2011-11-01

Although bacterial infection and heat stress are common causes of injury in human dental pulp cells (HDPCs), little is known about the potential defense mechanisms mediating their effects. This study examined the role of SIRT1 in mediating heat stress and lipopolysaccharide (LPS)-induced immune and defense gene expression in HDPCs. HDPCs were exposed to heat stress (42°C) for 30 minutes after stimulation with LPS (1 μg/mL) for 48 hours. The expression of defense genes was evaluated by reverse-transcriptase polymerase chain reaction, Western blotting, and enzyme-linked immunosorbent assay. LPS and heat stress synergistically increased the expression of SIRT1 and immune and defense genes such as interleukin (IL)-8, hemeoxygenase-1 (HO-1), and human β-defensin 2 (hBD-2). Resveratrol enhanced LPS- and heat stress-induced expression of HO-1 and hBD-2 but reduced IL-8 messenger RNA levels. The stimulation of HO-1 and hBD-2 messenger RNA expression by LPS and heat stress was inhibited by sirtinol; SIRT1 small interfering RNA; and inhibitors of p38, ERK, JNK, and nuclear factor κB. These results show for the first time that SIRT1 mediates the induction of immune and defense gene expression in HDPCs by LPS and heat stress. SIRT1 may play a pivotal role in host immune defense system in HDPCS. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Protective Effect of Silibinin on Learning and Memory Impairment in LPS-Treated Rats via ROS-BDNF-TrkB Pathway.

PubMed

Song, Xiaoyu; Zhou, Biao; Zhang, Pingping; Lei, Di; Wang, Yubin; Yao, Guodong; Hayashi, Toshihiko; Xia, Mingyu; Tashiro, Shin-Ichi; Onodera, Satoshi; Ikejima, Takashi

2016-07-01

Silibinin, a flavonoid derived from the herb milk thistle (Silybum marianum), has been used as a hepato-protectant in the clinical treatment of liver disease. In the present study, the effect of silibinin on lipopolysaccharide (LPS)-induced neuroinflammatory impairment in rats is investigated. Injection of LPS into lateral ventricle caused learning and memory impairment. Rats were treated with silibinin to see the effect in comparison with resveratrol as a positive control. Y-maze and Morris water maze tests showed that silibinin significantly attenuated memory damage caused by LPS treatment. At the molecular analysis, the levels of IL-1β and of IL-4 in the hippocampus were decreased and enhanced, respectively, by the treatment with silibinin. NF-κB expression was attenuated by silibinin treatment. Furthermore, generation of total reactive oxygen species (ROS) in the hippocampus was elevated in silibinin-treated groups, and so were the expressions of brain-derived neurotrophic factor (BDNF) and tyrosine receptor kinase B (TrkB). At the same time, LPS-induced reduction of neurons in hippocampus was reversed by silibinin. In conclusion, silibinin ameliorated the impairment of learning and memory of LPS-injection rats, possibly due to the activation of ROS-BDNF-TrkB pathway in the hippocampus as well as the suppression of inflammatory response. This study gives an insight on the beneficial consequences of ROS in central nervous system. Silibinin might be a potential candidate drug for neurodegenerative diseases.

Supplementation of lycopene attenuates lipopolysaccharide-induced amyloidogenesis and cognitive impairments via mediating neuroinflammation and oxidative stress.

PubMed

Wang, Jia; Li, Lixia; Wang, Zhuo; Cui, Yifan; Tan, Xintong; Yuan, Tian; Liu, Qian; Liu, Zhigang; Liu, Xuebo

2018-06-01

Neuroinflammation is documented to be the major culprit of Alzheimer's disease. Lycopene (LYC), a fat soluble carotenoid, exhibits neuroprotective function in several neurodegenerative disorders. However, the effects of LYC to countering systemic inflammation-induced amyloidogenesis and memory deficiency remain to be elucidated. In current study, 3-month-old male C57BL/6J mice were treated with 0.03% LYC (w/w, mixed into normal chow) for 5 weeks. The mice were then treated by intraperitoneal injection of LPS (0.25mg/kg) for 9 days. It was found that LYC inhibited LPS-induced memory loss by behavior tests including Y-maze test and Morris water test. Meanwhile, LYC prevented LPS-induced accumulation of Aβ, levels of amyloid precursor protein (APP), and suppressed neuronal β-secretase BACE1 and elevated the expressions of α-secretase ADAM10. Furthermore, LYC down-regulated the expression of IBA-1 (a marker of microglia activation), reduced the levels of inflammatory mediators and inhibited oxidative stress in LPS-treated mice. Moreover, LYC suppressed the phosphorylation of MAPKs, NFκB, and activated Nrf2 signaling pathways in LPS-treated BV2 microglial cells. Therefore, our study indicated that LYC could ameliorate LPS-induced neuroinflammation, oxidative stress, amyloidogenesis and cognitive impairments possibly through mediating MAPKs, NFκB and Nrf2 signaling pathways, indicating that LYC might be a nutritional preventive strategy in neuroinflammation-related diseases such as AD. Copyright © 2018 Elsevier Inc. All rights reserved.

Role of interferon regulatory factor-1 in lipopolysaccharide-induced mitochondrial damage and oxidative stress responses in macrophages

PubMed Central

Deng, Song-Yun; Zhang, Le-Meng; Ai, Yu-hang; Pan, Pin-Hua; Zhao, Shuang-Ping; Su, Xiao-Li; Wu, Dong-Dong; Tan, Hong-Yi; Zhang, Li-Na; Tsung, Allan

2017-01-01

Sepsis causes many early deaths; both macrophage mitochondrial damage and oxidative stress responses are key factors in its pathogenesis. Although the exact mechanisms responsible for sepsis-induced mitochondrial damage are unknown, the nuclear transcription factor, interferon regulatory factor-1 (IRF-1) has been reported to cause mitochondrial damage in several diseases. Previously, we reported that in addition to promoting systemic inflammation, IRF-1 promoted the apoptosis of and inhibited autophagy in macrophages. In the present study, we hypothesized that lipopolysaccharide (LPS)-induced IRF-1 activation in macrophages may promote mitochondrial damage and oxidative stress. In vitro, LPS was found to promote IRF-1 activation, reactive oxygen species (ROS) production, adenosine triphosphate (ATP) depletion, superoxide dismutase (SOD) consumption, malondialdehyde (MDA) accumulation and mitochondrial depolarization in macrophages in a time- and dose-dependent manner. These effects were abrogated in cells in which IRF-1 was knocked down. Furthermore, IRF-1 overexpression increased LPS-induced oxidative stress responses and mitochondrial damage. In vivo, peritoneal macrophages obtained from IRF-1 knockout (KO) mice produced less ROS and had less mitochondrial depolarization and damage following the administration of LPS, when compared to their wild-type (WT) counterparts. In addition, IRF-1 KO mice exhibited a decreased release of mitochondrial DNA (mtDNA) following the administration of LPS. Thus, IRF-1 may be a critical factor in augmenting LPS-induced oxidative stress and mitochondrial damage in macrophages. PMID:28849179

The complex that inserts lipopolysaccharide into the bacterial outer membrane forms a two-protein plug-and-barrel.

PubMed

Freinkman, Elizaveta; Chng, Shu-Sin; Kahne, Daniel

2011-02-08

The cell surfaces of Gram-negative bacteria are composed of lipopolysaccharide (LPS). This glycolipid is found exclusively in the outer leaflet of the asymmetric outer membrane (OM), where it forms a barrier to the entry of toxic hydrophobic molecules into the cell. LPS typically contains six fatty acyl chains and up to several hundred sugar residues. It is biosynthesized in the cytosol and must then be transported across two membranes and an aqueous intermembrane space to the cell surface. These processes are required for the viability of most Gram-negative organisms. The integral membrane β-barrel LptD and the lipoprotein LptE form an essential complex in the OM, which is necessary for LPS assembly. It is not known how this complex translocates large, amphipathic LPS molecules across the OM to the outer leaflet. Here, we show that LptE resides within the LptD β-barrel both in vitro and in vivo. LptD/E associate via an extensive interface; in one specific interaction, LptE contacts a predicted extracellular loop of LptD through the lumen of the β-barrel. Disrupting this interaction site compromises the biogenesis of LptD. This unprecedented two-protein plug-and-barrel architecture suggests how LptD/E can insert LPS from the periplasm directly into the outer leaflet of the OM to establish the asymmetry of the bilayer.

Concomitant Exposure to Ovalbumin and Endotoxin Augments Airway Inflammation but Not Airway Hyperresponsiveness in a Murine Model of Asthma

PubMed Central

Mac Sharry, John; Shalaby, Karim H.; Marchica, Cinzia; Farahnak, Soroor; Chieh-Li, Tien; Lapthorne, Susan; Qureshi, Salman T.; Shanahan, Fergus; Martin, James G.

2014-01-01

Varying concentrations of lipopolysaccharide (LPS) in ovalbumin (OVA) may influence the airway response to allergic sensitization and challenge. We assessed the contribution of LPS to allergic airway inflammatory responses following challenge with LPS-rich and LPS-free commercial OVA. BALB/c mice were sensitized with LPS-rich OVA and alum and then underwent challenge with the same OVA (10 µg intranasally) or an LPS-free OVA. Following challenge, bronchoalveolar lavage (BAL), airway responsiveness to methacholine and the lung regulatory T cell population (Treg) were assessed. Both OVA preparations induced BAL eosinophilia but LPS-rich OVA also evoked BAL neutrophilia. LPS-free OVA increased interleukin (IL)-2, IL-4 and IL-5 whereas LPS-rich OVA additionally increased IL-1β, IL-12, IFN-γ, TNF-α and KC. Both OVA-challenged groups developed airway hyperresponsiveness. TLR4-deficient mice challenged with either OVA preparation showed eosinophilia but not neutrophilia and had increased IL-5. Only LPS-rich OVA challenged mice had increased lung Tregs and LPS-rich OVA also induced in vitro Treg differentiation. LPS-rich OVA also induced a Th1 cytokine response in human peripheral blood mononuclear cells.We conclude that LPS-rich OVA evokes mixed Th1, Th2 and innate immune responses through the TLR-4 pathway, whereas LPS-free OVA evokes only a Th2 response. Contaminating LPS is not required for induction of airway hyperresponsiveness but amplifies the Th2 inflammatory response and is a critical mediator of the neutrophil, Th1 and T regulatory cell responses to OVA. PMID:24968337

L-3-n-Butylphthalide attenuates neuroinflammatory responses by downregulating JNK activation and upregulating Heme oxygenase-1 in lipopolysaccharide-treated mice.

PubMed

Zhao, Chun-Yang; Lei, Hui; Zhang, Yu; Li, Lin; Xu, Shao-Feng; Cai, Jie; Li, Ping-Ping; Wang, Ling; Wang, Xiao-Liang; Peng, Ying

2016-01-01

Microglia activation-induced neuroinflammation contributes to neuronal damage in neurodegenerative diseases. Inhibition of microglia activation and reduction of major neurotoxic cytokines have been becoming a therapeutic strategy for neurodegenerative diseases. L-3-n-Butylphthalide (L-NBP) has shown the potent neuroprotective effects in stroke and Alzheimer's disease animal models. The present study investigated the immune modulatory effects of L-NBP on pro-inflammatory cytokines and microglia activation in brain tissue induced by systemic lipopolysaccharide (LPS) treatment in C57BL/6 mice. Our results showed that systemic LPS treatment induced microglia activation in the brain. L-NBP treatment significantly suppressed the expression of proinflammatory cytokines, such as tumor necrosis factor (TNFα), interlukin-1β (IL-1β), interlukin-6 (IL-6), and interlukin-10 (IL-10) in LPS-treated mice. At the meantime, L-NBP treatment decreased the morphological activation of microglia. In addition, the phosphorylation level of JNK MAP kinase-signaling pathway was also inhibited by L-NBP in LPS-treated mice. Furthermore, L-NBP upregulated the expression of heme oxygenase (HO)-1, a key element in the anti-inflammation and anti-oxidative stress. These results suggested that L-NBP might be a promising candidate in delaying and reversing the progress of neurodegenerative diseases by inhibiting microglia activation.

Prevalence of lymphoplasmacytic synovitis in dogs with naturally occurring cranial cruciate ligament rupture.

PubMed

Erne, Jay B; Goring, Robert L; Kennedy, Fidelma A; Schoenborn, William C

2009-08-15

To determine the prevalence of lymphoplasmacytic synovitis (LPS) in dogs with naturally occurring cranial cruciate ligament (CCL) rupture and compare clinical, radiographic, cytologic, and histologic findings in dogs with and without LPS. Cross-sectional study. 110 dogs with naturally occurring CCL rupture. Histologic examination of synovial biopsy specimens obtained at the time of surgical treatment was used to identify dogs with LPS. Clinical, radiographic, cytologic, and histologic findings were compared between dogs with and without LPS. 56 (51%) dogs had histologic evidence of LPS. There were no significant differences in age, body weight, duration of lameness, severity of lameness, severity of radiographic signs of degenerative joint disease, extent of CCL rupture (partial vs complete), or gross appearance of the medial meniscus between dogs with and without LPS. Mean tibial plateau angle was significantly lower in dogs with LPS than in dogs without LPS, and dogs with LPS were significantly more likely to have neutrophils in their synovial fluid. Lymphocytes were seen in synovial fluid from a single dog with LPS. Results suggested that LPS was common in dogs with naturally occurring CCL rupture. However, only minor clinical, radiographic, cytologic, and histologic differences were identified between dogs with and without LPS.

Lipopolysaccharide binding protein enhances the responsiveness of alveolar macrophages to bacterial lipopolysaccharide. Implications for cytokine production in normal and injured lungs.

PubMed Central

Martin, T R; Mathison, J C; Tobias, P S; Letúrcq, D J; Moriarty, A M; Maunder, R J; Ulevitch, R J

1992-01-01

A plasma lipopolysaccharide (LPS)-binding protein (LBP) has been shown to regulate the response of rabbit peritoneal macrophages and human blood monocytes to endotoxin (LPS). We investigated whether LBP is present in lung fluids and the effects of LBP on the response of lung macrophages to LPS. Immunoreactive LBP was detectable in the lavage fluids of patients with the adult respiratory distress syndrome by immunoprecipitation followed by Western blotting, and also by specific immunoassay. In rabbits, the LBP appeared to originate outside of the lungs, inasmuch as mRNA transcripts for LBP were identified in total cellular RNA from liver, but not from lung homogenates or alveolar macrophages. Purified LBP enhanced the response of human and rabbit alveolar macrophages to both smooth form LPS (Escherichia coli O111B:4) and rough form LPS (Salmonella minnesota Re595). In the presence of LBP and LPS, the onset of tumor necrosis factor-alpha (TNF alpha) production occurred earlier and at an LPS threshold dose that was as much as 1,000-fold lower for both types of LPS. In rabbit alveolar macrophages treated with LBP and LPS, TNF alpha mRNA appeared earlier, reached higher levels, and had a prolonged half-life as compared with LPS treatment alone. Neither LPS nor LPS and LBP affected pHi or [Cai++] in alveolar macrophages. Specific monoclonal antibodies to CD14, a receptor that binds LPS/LBP complexes, inhibited TNF alpha production by human alveolar macrophages stimulated with LPS alone or with LPS/LBP complexes, indicating the importance of CD14 in mediating the effects of LPS on alveolar macrophages. Thus, immunoreactive LBP accumulates in lung lavage fluids in patients with lung injury and enhances LPS-stimulated TNF alpha gene expression in alveolar macrophages by a pathway that depends on the CD14 receptor. LBP may play an important role in augmenting TNF alpha expression by alveolar macrophages within the lungs. Images PMID:1281827

The α-MSH analogue AP214 attenuates rise in pulmonary pressure and fall in ejection fraction in lipopolysaccharide-induced systemic inflammatory response syndrome in pigs.

PubMed

Kristensen, Jens; Jonassen, Thomas E N; Rehling, Michael; Tønnesen, Else; Sloth, Erik; Nielsen, Søren; Frøkiaer, Jørgen

2011-01-01

The effect of an α-melanocyte stimulating hormone (α-MSH) analogue (AP214) on experimentally endotoxin-induced systemic inflammatory response syndrome (SIRS) was studied, because α-MSH in rodent models has shown promise in attenuating inflammatory response markers and associated organ damage in SIRS. SIRS is associated with considerable morbidity and mortality. Consequently, new treatment modalities are still warranted to address the different aspects of the pathophysiological process. SIRS was induced by lipopolysaccharide (LPS) (Escherichia coli endotoxin) infusion in anaesthetized Danish Landrace pigs (20-25 kg). The pigs received an α-MSH analogue (AP214) or saline as a bolus at the initiation of the LPS infusion. The hemodynamic response was registered as well as echocardiographic indices of left ventricular function. The cardiovascular response was recorded together with echocardiographic indices of left ventricular function in control and in intervention animals. AP214 reduced the early peak in pulmonary pressure and pulmonary vascular resistance by approximately 33%. Furthermore, AP214 prevented the decline in left ventricular fractional shortening as observed in the control group. Mean change and standard deviation in fractional shortening (ΔFS) in control group: - 7·3 (4·7), AP214 (low dose): 0·9 (8·2) and AP214 (high dose) 4·1 (6·0), P < 0·05 for both intervention groups versus control. In the porcine model, the peak increase in pulmonary pressure was attenuated, and the LPS-induced decline in left ventricular function was prevented. © 2010 The Authors. Clinical Physiology and Functional Imaging © 2010 Scandinavian Society of Clinical Physiology and Nuclear Medicine.

Computer simulation of uranyl uptake by the rough lipopolysaccharide membrane of Pseudomonas aeruginosa.

PubMed

Lins, Roberto D; Vorpagel, Erich R; Guglielmi, Matteo; Straatsma, T P

2008-01-01

Heavy metal environmental contaminants cannot be destroyed but require containment, preferably in concentrated form, in a solid or immobile form for recycling or final disposal. Microorganisms are able to take up and deposit high levels of contaminant metals, including radioactive metals such as uranium and plutonium, into their cell wall. Consequently, these microbial systems are of great interest as the basis for potential environmental bioremediation technologies. The outer membranes of Gram-negative microbes are highly nonsymmetric and exhibit a significant electrostatic potential gradient across the membrane. This gradient has a significant effect on the uptake and transport of charged and dipolar compounds. However, the effectiveness of microbial systems for environmental remediation will depend strongly on specific properties that determine the uptake of targeted contaminants by a particular cell wall. To aid in the design of microbial remediation technologies, knowledge of the factors that determine the affinity of a particular bacterial outer membrane for the most common ionic species found in contaminated soils and groundwater is of great importance. Using our previously developed model for the lipopolysaccharide (LPS) membrane of Pseudomonas aeruginosa, this work presents the potentials of mean force as the estimate of the free energy profile for uptake of sodium, calcium, chloride, uranyl ions, and a water molecule by the bacterial LPS membrane. A compatible classical parameter set for uranyl has been developed and validated. Results show that the uptake of uranyl is energetically a favorable process relative to the other ions studied. At neutral pH, this nuclide is shown to be retained on the surface of the LPS membrane through chelation with the carboxyl and hydroxyl groups located in the outer core.

Optical design and evaluation of a 4 mm cost-effective ultra-high-definition arthroscope.

PubMed

Cheng, Dewen; Wang, Yongtian; Yu, Lu; Liu, Xiaohua

2014-08-01

High definition and magnification rigid endoscope plays an important role in modern minimally invasive medical surgery and diagnosis. In this paper, we present the design and evaluation methods of a high definition rigid endoscope, specifically an arthroscope, with a large depth of field (DOF). The incident heights and exit angles of the sampled rays on the relay lens are controlled during the optimization process to ensure an effective field view (70°) and a normal ray path within the limited lens diameter of 2.7 mm. The lens is set up as a multi-configuration system with two extreme and one middle object distances to cover a large DOF. As a result, an entrance pupil of 0.3 mm is achieved for the first time, to bring the theoretical resolution to 23.1 lps/mm in the object space at a working distance of 20 mm, with the wavelength of 0.532 um. The modulation transfer function (MTF) curves approach diffraction limit, and the values are all higher than 0.3 at 160 line pairs/mm (lps/mm) in the image space. Meanwhile, stray light caused by total internal reflection on the inner wall of the rod lenses and the objective lens is eliminated. The measured resolution in the object space at a 20 mm working distance is 22.3 lps/mm, and test results show that other performance characteristics also fulfill design requirements. The relay lenses are designed with only one type of the spacer and two types of lenses to greatly reduce the fabrication and assembly cost. The design method has important research and application values for lens systems used in modern minimally invasive medical surgery and industrial non-destructive testing area.

The Interactive Roles of Lipopolysaccharides and dsRNA/Viruses on Respiratory Epithelial Cells and Dendritic Cells in Allergic Respiratory Disorders: The Hygiene Hypothesis.

PubMed

Lin, Tsang-Hsiung; Su, Hsing-Hao; Kang, Hong-Yo; Chang, Tsung-Hsien

2017-10-23

The original hygiene hypothesis declares "more infections in early childhood protect against later atopy". According to the hygiene hypothesis, the increased incidence of allergic disorders in developed countries is explained by the decrease of infections. Epithelial cells and dendritic cells play key roles in bridging the innate and adaptive immune systems. Among the various pattern-recognition receptor systems of epithelial cells and dendritic cells, including toll-like receptors (TLRs), nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs) and others, TLRs are the key systems of immune response regulation. In humans, TLRs consist of TLR1 to TLR10. They regulate cellular responses through engagement with TLR ligands, e.g., lipopolysaccharides (LPS) acts through TLR4 and dsRNA acts through TLR3, but there are certain common components between these two TLR pathways. dsRNA activates epithelial cells and dendritic cells in different directions, resulting in allergy-related Th2-skewing tendency in epithelial cells, and Th1-skewing tendency in dendritic cells. The Th2-skewing effect by stimulation of dsRNA on epithelial cells could be suppressed by the presence of LPS above some threshold. When LPS level decreases, the Th2-skewing effect increases. It may be via these interrelated networks and related factors that LPS modifies the allergic responses and provides a plausible mechanism of the hygiene hypothesis. Several hygiene hypothesis-related phenomena, seemingly conflicting, are also discussed in this review, along with their proposed mechanisms.

Effects of normal saline and selenium-enriched hot spring water on experimentally induced rhinosinusitis in rats.

PubMed

Kim, Dong-Hyun; Yeo, Sang Won

2013-01-01

This prospective, randomized, and controlled study examined the effects of normal saline and selenium-enriched hot spring water on experimentally induced rhinosinusitis in rats. The study comprised two control groups (untreated and saline-treated) and three experimental groups of Sprague Dawley rats. The experimental groups received an instillation of lipopolysaccharide (LPS) only, LPS+normal saline (LPS/saline), or LPS+selenium-enriched hot spring water (LPS/selenium). Histopathological changes were identified using hematoxylin-eosin staining. Leakage of exudate was identified using fluorescence microscopy. Microvascular permeability was measured using the Evans blue dye technique. Expression of the Muc5ac gene was measured using reverse transcription-polymerase chain reaction. Mucosal edema and expression of the Muc5ac gene were significantly lower in the LPS/saline group than in the LPS group. Microvascular permeability, mucosal edema, and expression of the Muc5ac gene were significantly lower in the LPS/selenium group than in the LPS group. Mucosal edema was similar in the LPS/selenium group and LPS/saline group, but capillary permeability and Muc5ac expression were lower in the LPS/selenium group. This study shows that normal saline and selenium-enriched hot spring water reduce inflammatory activity and mucus hypersecretion in LPS-induced rhinosinusitis in rats. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Intramammary infusion of Escherichia coli lipopolysaccharide negatively affects feed intake, chewing, and clinical variables, but some effects are stronger in cows experiencing subacute rumen acidosis.

PubMed

Aditya, S; Humer, E; Pourazad, P; Khiaosa-Ard, R; Huber, J; Zebeli, Q

2017-02-01

Feeding high-grain diets increases the risk of subacute rumen acidosis (SARA) and adversely affects rumen health. This condition might impair the responsiveness of cows when they are exposed to external infectious stimuli such as lipopolysaccharide (LPS). The main objective of this study was to evaluate various responses to intramammary LPS infusion in healthy dairy cows and those experimentally subjected to SARA. Eighteen early-lactating Simmental cows were subjected to SARA (n = 12) or control (CON; n = 6) feeding conditions. Cows of the control group received a diet containing 40% concentrates (DM basis) throughout the experiment. The intermittent SARA feeding regimen consisted in feeding the cows a ration with 60% concentrate (DM basis) for 32 d, consisting of a first SARA induction for 8 d, switched to the CON diet for 7 d, and re-induction during the last 17 d. On d 30 of the experiment, 6 SARA (SARA-LPS) and 6 CON (CON-LPS) cows were intramammary challenged once with a single dose of 50 μg of LPS from Escherichia coli (O26:B6), whereas the other 6 SARA cows (SARA-PLA) received 10 mL of sterile saline solution as placebo. To confirm the induction of SARA, the reticular pH was continuously monitored via wireless pH probes. The DMI remained unchanged between SARA and CON cows during the feeding experiment, but was reduced in both treatment groups receiving the LPS infusion compared with SARA-PLA, whereby a significant decline was observed for cows of the SARA-LPS treatment (-38%) compared with CON-LPS (-19%). The LPS infusion did not affect the reticuloruminal pH dynamics, but significantly enhanced ruminal temperature and negatively affected chewing behavior. The ruminal temperature increased after the LPS infusion and peaked about 1 h earlier in SARA-LPS cows compared with the cows of the CON-LPS treatment. Moreover, a significant decline in milk yield was found in SARA-LPS compared with CON-LPS following the LPS infusion. Cows receiving LPS had elevated somatic cell counts, protein, and fat contents in milk as well as decreased lactose contents and pH following the LPS infusion, whereby the changes in milk constituents were more pronounced in SARA-LPS than CON-LPS cows. Rectal temperature and pulse rate were highest 6 h after LPS infusion, but rumen contractions were not affected by the LPS infusion. The data suggest that a single intramammary LPS infusion induced fever and negatively affected feed intake, chewing activity, rectal temperature, and milk yield and composition, whereby these effects were more pronounced in SARA cows. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Antimicrobial peptides and nitric oxide production by neutrophils from periodontitis subjects

PubMed Central

Mariano, F.S.; Campanelli, A.P.; Nociti, F.H.; Mattos-Graner, R.O.; Gonçalves, R.B.

2012-01-01

Neutrophils play an important role in periodontitis by producing nitric oxide (NO) and antimicrobial peptides, molecules with microbicidal activity via oxygen-dependent and -independent mechanisms, respectively. It is unknown whether variation in the production of antimicrobial peptides such as LL-37, human neutrophil peptides (HNP) 1-3, and NO by neutrophils influences the pathogenesis of periodontal diseases. We compared the production of these peptides and NO by lipopolysaccharide (LPS)-stimulated neutrophils isolated from healthy subjects and from patients with periodontitis. Peripheral blood neutrophils were cultured with or without Aggregatibacter actinomycetemcomitans-LPS (Aa-LPS), Porphyromonas gingivalis-LPS (Pg-LPS) and Escherichia coli-LPS (Ec-LPS). qRT-PCR was used to determine quantities of HNP 1-3 and LL-37 mRNA in neutrophils. Amounts of HNP 1-3 and LL-37 proteins in the cell culture supernatants were also determined by ELISA. In addition, NO levels in neutrophil culture supernatants were quantitated by the Griess reaction. Neutrophils from periodontitis patients cultured with Aa-LPS, Pg-LPS and Ec-LPS expressed higher HNP 1-3 mRNA than neutrophils from healthy subjects. LL-37 mRNA expression was higher in neutrophils from patients stimulated with Aa-LPS. Neutrophils from periodontitis patients produced significantly higher LL-37 protein levels than neutrophils from healthy subjects when stimulated with Pg-LPS and Ec-LPS, but no difference was observed in HNP 1-3 production. Neutrophils from periodontitis patients cultured or not with Pg-LPS and Ec-LPS produced significantly lower NO levels than neutrophils from healthy subjects. The significant differences in the production of LL-37 and NO between neutrophils from healthy and periodontitis subjects indicate that production of these molecules might influence individual susceptibility to important periodontal pathogens. PMID:22850872

Lipopolysaccharide stimulates HepG2 human hepatoma cells in the presence of lipopolysaccharide-binding protein via CD14.

PubMed

Nanbo, A; Nishimura, H; Muta, T; Nagasawa, S

1999-02-01

Lipopolysaccharide (LPS)-binding protein (LBP), an opsonin for activation of macrophages by bacterial LPS, is synthesized in hepatocytes and is known to be an acute phase protein. Recently, cytokine-induced production of LBP was reported to increase 10-fold in hepatocytes isolated from LPS-treated rats, compared with those from normal rats. However, the mechanism by which the LPS treatment enhances the effect of cytokines remains to be clarified. In the present study, we examined whether LPS alone or an LPS/LBP complex directly stimulates the hepatocytes, leading to acceleration of the cytokine-induced LBP production. HepG2 cells (a human hepatoma cell line) were shown to express CD14, a glycosylphosphatidylinositol-anchored LPS receptor, by both RT/PCR and flow cytometric analyses. An LPS/LBP complex was an effective stimulator for LBP and CD14 production in HepG2 cells, but stimulation of the cells with either LPS or LBP alone did not significantly accelerate the production of these proteins. The findings were confirmed by semiquantitative RT/PCR analysis of mRNA levels of LBP and CD14 in HepG2 cells after stimulation with LPS alone and an LPS/LBP complex. In addition, two monoclonal antibodies (mAbs) to CD14 (3C10 and MEM-18) inhibited LPS/LBP-induced cellular responses of HepG2 cells. Furthermore, prestimulation of HepG2 cells with LPS/LBP augmented cytokine-induced production and gene expression of LBP and CD14. All these findings suggest that an LPS/LBP complex, but not free LPS, stimulates HepG2 cells via CD14 leading to increased basal and cytokine-induced LBP and CD14 production.

Establishment of hydrochloric acid/lipopolysaccharide-induced pelvic inflammatory disease model.

PubMed

Oh, Yeonsu; Lee, Jaehun; Kim, Hyeon-Cheol; Hahn, Tae-Wook; Yoon, Byung-Il; Han, Jeong-Hee; Kwon, Yong-Soo; Park, Joung Jun; Koo, Deog-Bon; Rhee, Ki-Jong; Jung, Bae Dong

2016-09-30

Pelvic inflammatory disease (PID), which is one of the most problematic complications experienced by women with sexually transmitted diseases, frequently causes secondary infections after reproductive abnormalities in veterinary animals. Although the uterus is self-protective, it becomes fragile during periods or pregnancy. To investigate PID, bacteria or lipopolysaccharide (LPS) extracted from gram negative bacteria has been used to induce the disease in several animal models. However, when LPS is applied to the peritoneum, it often causes systemic sepsis leading to death and the PID was not consistently demonstrated. Hydrochloric acid (HCl) has been used to induce inflammation in the lungs and stomach but not tested for reproductive organs. In this study, we developed a PID model in mice by HCl and LPS sequential intracervical (i.c.) administration. The proinflammatory cytokines, interleukin (IL)-1β, IL-6 and tumor necrosis factor-α, were detected in the mouse uterus by western blot analysis and cytokine enzyme-linked immunosorbent assay after HCl (25 mg/kg) administration i.c. followed by four LPS (50 mg/kg) treatments. Moreover, mice exhibited increased infiltration of neutrophils in the endometrium and epithelial layer. These results suggest that ic co-administration of HCl and LPS induces PID in mice. This new model may provide a consistent and reproducible PID model for future research.

Establishment of hydrochloric acid/lipopolysaccharide-induced pelvic inflammatory disease model

PubMed Central

Oh, Yeonsu; Lee, Jaehun; Kim, Hyeon-Cheol; Hahn, Tae-Wook; Yoon, Byung-Il; Han, Jeong-Hee; Kwon, Yong-Soo; Park, Joung Jun; Koo, Deog-Bon; Rhee, Ki-Jong

2016-01-01

Pelvic inflammatory disease (PID), which is one of the most problematic complications experienced by women with sexually transmitted diseases, frequently causes secondary infections after reproductive abnormalities in veterinary animals. Although the uterus is self-protective, it becomes fragile during periods or pregnancy. To investigate PID, bacteria or lipopolysaccharide (LPS) extracted from gram negative bacteria has been used to induce the disease in several animal models. However, when LPS is applied to the peritoneum, it often causes systemic sepsis leading to death and the PID was not consistently demonstrated. Hydrochloric acid (HCl) has been used to induce inflammation in the lungs and stomach but not tested for reproductive organs. In this study, we developed a PID model in mice by HCl and LPS sequential intracervical (i.c.) administration. The proinflammatory cytokines, interleukin (IL)-1β, IL-6 and tumor necrosis factor-α, were detected in the mouse uterus by western blot analysis and cytokine enzyme-linked immunosorbent assay after HCl (25 mg/kg) administration i.c. followed by four LPS (50 mg/kg) treatments. Moreover, mice exhibited increased infiltration of neutrophils in the endometrium and epithelial layer. These results suggest that ic co-administration of HCl and LPS induces PID in mice. This new model may provide a consistent and reproducible PID model for future research. PMID:26726020

Lipopolysaccharide and hypoxia significantly alters interleukin-8 and macrophage chemoattractant protein-1 production by human fibroblasts but not fibrosis related factors.

PubMed

Eleftheriadis, T; Liakopoulos, V; Lawson, B; Antoniadi, G; Stefanidis, I; Galaktidou, G

2011-07-01

Besides extracellular matrix production, fibroblasts are able to produce various cytokines. Their ubiquitous position makes fibroblasts appropriate cells for sensing various noxious stimuli and for attracting immune cells in the affected area. In the present study the effect of lipopolysaccharide (LPS) and cobalt chloride (CoCl(2)) on the above fibroblasts functions were evaluated in primary human skin fibroblasts cultures. Collagen, matrix metalloproteinase-1, tissue inhibitor of metalloproteinases-1, transforming growth factor-β1, interleukin-8 (IL-8) and macrophage chemoattractant protein-1 (MCP-1) were measured in fibroblasts culture supernatants. Fibroblasts proliferation and viability were assessed as well. Hypoxia inducible factor-1α and the phosphorylated p65 portion of NF-κB were assessed in fibroblasts protein extracts. LPS and CoCl(2) had a minor effect on fibrosis related factors in human primary fibroblasts, possibly due to the absence of interplay with other cell types in the used experimental system. On the contrary both LPS and CoCl(2) increased significantly IL-8. LPS also increased considerably MCP-1, but CoCl(2) decreased it. Thus LPS and CoCl(2) induce a sentinel, nevertheless not identical, phenotype in primary human fibroblasts. The last disparity could result in different body response to infectious or hypoxic noxious stimuli.

Pleiotropic Effects of White Willow Bark and 1,2-Decanediol on Human Adult Keratinocytes.

PubMed

Bassino, Eleonora; Gasparri, Franco; Munaron, Luca

2018-01-01

Acne vulgaris is a common skin defect, usually occurring during adolescence, but often it can persist in adults leaving permanent face scarring. Acne is usually treated with topical drugs, oral antibiotics, retinoids, and hormonal therapies, but medicinal plants are increasingly employed. To investigate the protective role of white willow bark (WWB) and 1,2-decanediol (DD) on the damage caused by lipopolysaccharides (LPS) on human adult keratinocytes (HaCaT). HaCaT were exposed to LPS alone or in association with WWB and DD. Epidermal viability, metabolic modulation, inflammatory activity, and cell migration were assessed with both common standardized protocols or high-throughput screening systems. The preincubation of HaCaT with WWB and DD (used separately or in combination) differently prevented the alterations induced by LPS on HaCaT in terms of growth factor release (IGF, EGF, VEGF), cytokine production (IL-1α, IL-6, IL-8), or expression of the transcription factor FOXO-I. Moreover, they partially restore wound repair lowered by LPS. These results suggest that both natural compounds were able to differently affect several functions of LPS-stressed keratinocytes suggesting their potential role for the prevention of acne vulgaris, without adverse effects. © 2017 S. Karger AG, Basel.

Anti-LPS antibodies reduce endotoxemia in whole body Co-60 irradiated primates - A preliminary report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wells, M.T.; Gaffin, S.L.; Wessels, B.C.

1990-09-01

A previously established primate model was used to evaluate the role of lipopolysaccharide (LPS, endotoxin) in radiation sickness. Vervet monkeys were Co-60 irradiated with an LD100 exposure and had periodic blood samples taken for the determination of LPS and anti-LPS lgG antibodies and for bacteriological studies. On day 2 postirradiation, primates were treated with either sterile 0.9 percent saline, or equine anti-LPS hyperimmune plasma, or tripotassium-dicitrato-bismuthate (Denol). Results indicate that anti-LPS-treated animals survived significantly longer than both the other groups and, since LPS may cause nausea, vomiting, diarrhea, anorexia, and headaches, it is suggested that Anti-LPS administration may be ofmore » value in reducing plasma LPS concentration in humans and improving their performance and survivability. 24 refs.« less

Anti-Inflammatory and Osteoprotective Effects of Cannabinoid-2 Receptor Agonist HU-308 in a Rat Model of Lipopolysaccharide-Induced Periodontitis.

PubMed

Ossola, Cesar A; Surkin, Pablo N; Mohn, Claudia E; Elverdin, Juan C; Fernández-Solari, Javier

2016-06-01

Anti-inflammatory and immunologic properties of cannabinoids have been reported in several tissues. Expression of cannabinoid receptor Type 2 was reported in osteoblasts and osteoclasts, suggesting a key role in bone metabolism. The aim of this study is to assess the effect of treatment with cannabinoid-2 receptor agonist HU-308 in the oral health of rats subjected to lipopolysaccharide (LPS)-induced periodontitis. Twenty-four rats were distributed in four groups (six rats per group): 1) control rats; 2) sham rats; 3) rats submitted to experimental periodontitis (LPS); and 4) rats submitted to experimental periodontitis and treated with HU-308 (LPS+HU). In groups LPS and LPS+HU, periodontitis was induced by LPS (1 mg/mL) injected into the gingival tissue (GT) of maxillary and mandibular first molars and into the interdental space between the first and second molars, 3 days per week for 6 weeks. In group LPS+HU, HU-308 (500 ng/mL) was applied topically to the GT daily. Alveolar bone loss resulting from LPS-induced periodontitis was significantly attenuated with HU-308 treatment (LPS+HU), measured by macroscopic and histologic examination. Treatment also reduced gingival production of inflammatory mediators augmented in LPS-injected rats, such as: 1) inducible nitric oxide (iNOS) activity (LPS: 90.18 ± 36.51 pmol/minute/mg protein versus LPS+HU: 16.37 ± 4.73 pmol/minute/mg protein; P <0.05); 2) tumor necrosis factor alpha (LPS: 185.70 ± 25.63 pg/mg protein versus LPS+HU: 95.89 ± 17.47 pg/mg protein; P <0.05); and 3) prostaglandin E2 (PGE2) (LPS: 159.20 ± 38.70 pg/mg wet weight versus LPS+HU: 71.25 ± 17.75 pg/mg wet weight; P <0.05). Additionally, HU-308 treatment prevented the inhibitory effect of LPS-induced periodontitis on the salivary secretory response to pilocarpine. Moreover, iNOS activity and PGE2 content, which were increased by LPS-induced periodontitis in the submandibular gland, returned to control values after HU-308 treatment. This study demonstrates anti-inflammatory, osteoprotective, and prohomeostatic effects of HU-308 in oral tissues of rats with LPS-induced periodontitis.

The Stimulated Innate Resistance Event in Bordetella pertussis Infection Is Dependent on Reactive Oxygen Species Production

PubMed Central

Zurita, E.; Moreno, G.; Errea, A.; Ormazabal, M.; Rumbo, M.

2013-01-01

The exacerbated induction of innate immune responses in airways can abrogate diverse lung infections by a phenomenon known as stimulated innate resistance (StIR). We recently demonstrated that the enhancement of innate response activation can efficiently impair Bordetella pertussis colonization in a Toll-like receptor 4 (TLR4)-dependent manner. The aim of this work was to further characterize the effect of lipopolysaccharide (LPS) on StIR and to identify the mechanisms that mediate this process. Our results showed that bacterial infection was completely abrogated in treated mice when the LPS of B. pertussis (1 μg) was added before (48 h or 24 h), after (24 h), or simultaneously with the B. pertussis challenge (107 CFU). Moreover, we detected that LPS completely cleared bacterial infection as soon as 2 h posttreatment. This timing suggests that the observed StIR phenomenon should be mediated by fast-acting antimicrobial mechanisms. Although neutrophil recruitment was already evident at this time point, depletion assays using an anti-GR1 antibody showed that B. pertussis clearance was achieved even in the absence of neutrophils. To evaluate the possible role of free radicals in StIR, we performed animal assays using the antioxidant N-acetyl cysteine (NAC), which is known to inactivate oxidant species. NAC administration blocked the B. pertussis clearance induced by LPS. Nitrite concentrations were also increased in the LPS-treated mice; however, the inhibition of nitric oxide synthetases did not suppress the LPS-induced bacterial clearance. Taken together, our results show that reactive oxygen species (ROS) play an essential role in the TLR4-dependent innate clearance of B. pertussis. PMID:23630952

The triterpenoid CDDO-imidazolide reduces immune cell infiltration and cytokine secretion in the KrasG12D;Pdx1-Cre (KC) mouse model of pancreatic cancer

PubMed Central

Leal, Ana S.; Sporn, Michael B.; Pioli, Patricia A.; Liby, Karen T.

2016-01-01

Because the 5-year survival rate for pancreatic cancer remains under 10%, new drugs are needed for the prevention and treatment of this devastating disease. Patients with chronic pancreatitis have a 12-fold higher risk of developing pancreatic cancer. LSL-KrasG12D/+;Pdx-1-Cre (KC) mice replicate the genetics, symptoms and histopathology found in human pancreatic cancer. Immune cells infiltrate into the pancreas of these mice and produce inflammatory cytokines that promote tumor growth. KC mice are particularly sensitive to the effects of lipopolysaccharide (LPS), as only 48% of KC mice survived an LPS challenge while 100% of wildtype (WT) mice survived. LPS also increased the percentage of CD45+ immune cells in the pancreas and immunosuppressive Gr1+ myeloid-derived suppressor cell in the spleen of these mice. The triterpenoid CDDO-imidazolide (CDDO-Im) not only reduced the lethal effects of LPS (71% survival) but also decreased the infiltration of CD45+ cells into the pancreas and the percentage of Gr1+ myeloid-derived suppressor cell in the spleen of KC mice 4–8 weeks after the initial LPS challenge. While the levels of inflammatory cytokine levels were markedly higher in KC mice versus WT mice challenged with LPS, CDDO-Im significantly decreased the production of IL-6, CCL-2, vascular endothelial growth factor and G-CSF in the KC mice. All of these cytokines are prognostic markers in pancreatic cancer or play important roles in the progression of this disease. Disrupting the inflammatory process with drugs such as CDDO-Im might be useful for preventing pancreatic cancer, especially in high-risk populations. PMID:27659181

Serum Endotoxins and Flagellin and Risk of Colorectal Cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC) Cohort

PubMed Central

Kong, So Yeon; Tran, Hao Quang; Gewirtz, Andrew T.; McKeown-Eyssen, Gail; Fedirko, Veronika; Romieu, Isabelle; Tjønneland, Anne; Olsen, Anja; Overvad, Kim; Boutron-Ruault, Marie-Christine; Bastide, Nadia; Affret, Aurélie; Kühn, Tilman; Kaaks, Rudolf; Boeing, Heiner; Aleksandrova, Krasimira; Trichopoulou, Antonia; Kritikou, Maria; Vasilopoulou, Effie; Palli, Domenico; Krogh, Vittorio; Mattiello, Amalia; Tumino, Rosario; Naccarati, Alessio; Bueno-de-Mesquita, H.Bas; Peeters, Petra H.; Weiderpass, Elisabete; Quirós, J. Ramón; Sala, Núria; Sánchez, María-José; Huerta Castaño, José María; Barricarte, Aurelio; Dorronsoro, Miren; Werner, Mårten; Wareham, Nicholas J.; Khaw, Kay-Tee; Bradbury, Kathryn E.; Freisling, Heinz; Stavropoulou, Faidra; Ferrari, Pietro; Gunter, Marc J.; Cross, Amanda J.; Riboli, Elio; Bruce, W. Robert

2017-01-01

Background Chronic inflammation and oxidative stress are thought to be involved in colorectal cancer (CRC) development. These processes may be contributed to by leakage of bacterial products, such as lipopolysaccharide (LPS) and flagellin, across the gut barrier. The objective of this study, nested within a prospective cohort, was to examine associations between circulating LPS and flagellin serum antibody levels and CRC risk. Methods 1,065 incident CRC cases (colon n=667; rectal n=398) were matched (1:1) to control subjects. Serum flagellin- and LPS-specific IgA and IgG levels were quantitated by ELISA. Multivariable conditional logistic regression models were used to calculate odds ratios (OR) and 95% confidence intervals (CI), adjusting for multiple relevant confouding factors. Results Overall, elevated anti-LPS and anti-flagellin biomarker levels were not associated with CRC risk. After testing potential interactions by various factors relevant for CRC risk and anti-LPS and anti-flagellin, sex was identified as a statistically significant interaction factor (pinteraction < 0.05 for all the biomarkers). Analyses stratified by sex showed a statistically significant positive CRC risk association for men (fully-adjusted OR for highest vs. lowest quartile for total anti-LPS+flagellin = 1.66; 95% CI, 1.10-2.51; ptrend = 0.049) while a borderline statistically significant inverse association was observed for women (fully-adjusted OR= 0.70; 95%CI, 0.47-1.02; ptrend = 0.18). Conclusion In this prospective study on European populations, we found bacterial exposure levels to be positively associated to CRC risk among men while in women, a possible inverse association may exist. Impact Further studies are warranted to better clarify these preliminary observations. PMID:26823475

fLPS: Fast discovery of compositional biases for the protein universe.

PubMed

Harrison, Paul M

2017-11-13

Proteins often contain regions that are compositionally biased (CB), i.e., they are made from a small subset of amino-acid residue types. These CB regions can be functionally important, e.g., the prion-forming and prion-like regions that are rich in asparagine and glutamine residues. Here I report a new program fLPS that can rapidly annotate CB regions. It discovers both single-residue and multiple-residue biases. It works through a process of probability minimization. First, contigs are constructed for each amino-acid type out of sequence windows with a low degree of bias; second, these contigs are searched exhaustively for low-probability subsequences (LPSs); third, such LPSs are iteratively assessed for merger into possible multiple-residue biases. At each of these stages, efficiency measures are taken to avoid or delay probability calculations unless/until they are necessary. On a current desktop workstation, the fLPS algorithm can annotate the biased regions of the yeast proteome (>5700 sequences) in <1 s, and of the whole current TrEMBL database (>65 million sequences) in as little as ~1 h, which is >2 times faster than the commonly used program SEG, using default parameters. fLPS discovers both shorter CB regions (of the sort that are often termed 'low-complexity sequence'), and milder biases that may only be detectable over long tracts of sequence. fLPS can readily handle very large protein data sets, such as might come from metagenomics projects. It is useful in searching for proteins with similar CB regions, and for making functional inferences about CB regions for a protein of interest. The fLPS package is available from: http://biology.mcgill.ca/faculty/harrison/flps.html , or https://github.com/pmharrison/flps , or is a supplement to this article.

Lack of matrix metalloproteinase 3 in mouse models of lung injury ameliorates the pulmonary inflammatory response in female but not in male mice.

PubMed

Puntorieri, Valeria; McCaig, Lynda A; Howlett, Christopher J; Yao, Li-Juan; Lewis, James F; Yamashita, Cory M; Veldhuizen, Ruud A W

2016-09-01

The acute respiratory distress syndrome (ARDS) is a complex pulmonary disorder in which the local release of cytokines and chemokines appears central to the pathophysiology. Based on the known role of matrix metalloproteinase-3 (MMP3) in inflammatory processes, the objective was to examine the role of MMP3 in the pathogenesis of ARDS through the modulation of pulmonary inflammation. Female and male, wild type (MMP3 +/+ ) and knock out (MMP3 -/- ) mice were exposed to two, clinically relevant models of ARDS including (i) lipopolysaccharide (LPS)-induced lung injury, and (ii) hydrochloric acid-induced lung injury. Parameters of lung injury and inflammation were assessed through measurements in lung lavage including total protein content, inflammatory cell influx, and concentrations of mediators such as TNF-α, IL-6, G-CSF, CXCL1, CXCL2, and CCL2. Lung histology and compliance were also evaluated in the LPS model of injury. Following intra-tracheal LPS instillation, all mice developed lung injury, as measured by an increase in lavage neutrophils, and decrease in lung compliance, with no overall effect of genotype observed. Increased concentrations of lavage inflammatory cytokines and chemokines were also observed following LPS injury, however, LPS-instilled female MMP3 -/- mice had lower levels of inflammatory mediators compared to LPS-instilled female MMP3 +/+ mice. This effect of the genotype was not observed in male mice. Similar findings, including the MMP3-related sex differences, were also observed after acid-induced lung injury. MMP3 contributes to the pathogenesis of ARDS, by affecting the pulmonary inflammatory response in female mice in relevant models of lung injury.

Post-Transcriptional Regulation of Urokinase-type Plasminogen Activator Receptor Expression in Lipopolysaccharide-induced Acute Lung Injury

PubMed Central

Bhandary, Yashodhar P.; Velusamy, Thirunavukkarasu; Shetty, Praveenkumar; Shetty, Rashmi S.; Idell, Steven; Cines, Douglas B.; Jain, Deepika; Bdeir, Khalil; Abraham, Edward; Tsuruta, Yuko; Shetty, Sreerama

2009-01-01

Rationale: Urokinase-type plasminogen activator (uPA) receptor (uPAR) is required for the recruitment of neutrophils in response to infection. uPA induces its own expression in lung epithelial cells, which involves its interaction with cell surface uPAR. Regulation of uPAR expression is therefore crucial for uPA-mediated signaling in infectious acute lung injury (ALI). Objectives: To determine the role of uPA in uPAR expression during ALI caused by sepsis. Methods: We used Western blot, Northern blot, Northwestern assay, and immunohistochemistry. Phosphate-buffered saline– and lipopolysaccharide (LPS)-treated wild-type and uPA−/− mice were used. Measurements and Main Results: Biological activities of uPA, including proteolysis, cell adhesion, migration, proliferation, and differentiation, are dependent on its association with uPAR. Bacterial endotoxin (LPS) is a major cause of pulmonary dysfunction and infection-associated mortality. The present study shows that LPS induces uPAR expression both in vitro and in vivo, and that the mechanism involves post-transcriptional stabilization of uPAR mRNA by reciprocal interaction of phosphoglycerate kinase (PGK) and heterogeneous nuclear ribonucleoprotein C (hnRNPC) with uPAR mRNA coding region and 3′ untranslated region determinants, respectively. The process involves tyrosine phosphorylation of PGK and hnRNPC. uPA−/− mice failed to induce uPAR expression after LPS treatment. In these mice, LPS treatment failed to alter the binding of PGK and hnRNPC protein with uPAR mRNA due to lack of tyrosine phosphorylation. Conclusions: Our study shows that induction of LPS-mediated uPAR expression is mediated through tyrosine phosphorylation of PGK and hnRNPC. This involves expression of uPA as an obligate intermediary. PMID:19029002

Lipopolysaccharide (LPS)-binding protein stimulates CD14-dependent Toll-like receptor 4 internalization and LPS-induced TBK1-IKKϵ-IRF3 axis activation.

PubMed

Tsukamoto, Hiroki; Takeuchi, Shino; Kubota, Kanae; Kobayashi, Yohei; Kozakai, Sao; Ukai, Ippo; Shichiku, Ayumi; Okubo, Misaki; Numasaki, Muneo; Kanemitsu, Yoshitomi; Matsumoto, Yotaro; Nochi, Tomonori; Watanabe, Kouichi; Aso, Hisashi; Tomioka, Yoshihisa

2018-05-14

Toll-like receptor 4 (TLR4) is an indispensable immune receptor for lipopolysaccharide (LPS), a major component of the Gram-negative bacterial cell wall. Following LPS stimulation, TLR4 transmits the signal from the cell surface and becomes internalized in an endosome. However, the spatial regulation of TLR4 signaling is not fully understood. Here, we investigated the mechanisms of LPS-induced TLR4 internalization and clarified the roles of the extracellular LPS-binding molecules, LPS-binding protein (LBP), and glycerophosphatidylinositol-anchored protein (CD14). LPS stimulation of CD14-expressing cells induced TLR4 internalization in the presence of serum, and an inhibitory anti-LBP mAb blocked its internalization. Addition of LBP to serum-free cultures restored LPS-induced TLR4 internalization to comparable levels of serum. The secretory form of the CD14 (sCD14) induced internalization but required a much higher concentration than LBP. An inhibitory anti-sCD14 mAb was ineffective for serum-mediated internalization. LBP lacking the domain for LPS transfer to CD14 and a CD14 mutant with reduced LPS binding both attenuated TLR4 internalization. Accordingly, LBP is an essential serum molecule for TLR4 internalization, and its LPS transfer to membrane-anchored CD14 (mCD14) is a prerequisite. LBP induced the LPS-stimulated phosphorylation of TBK1, IKKϵ, and IRF3, leading to IFN-β expression. However, LPS-stimulated late activation of NFκB or necroptosis were not affected. Collectively, our results indicate that LBP controls LPS-induced TLR4 internalization, which induces TLR adaptor molecule 1 (TRIF)-dependent activation of the TBK1-IKKϵ-IRF3-IFN-β pathway. In summary, we showed that LBP-mediated LPS transfer to mCD14 is required for serum-dependent TLR4 internalization and activation of the TRIF pathway. Copyright © 2018, The American Society for Biochemistry and Molecular Biology.

Effect of molecular hydrogen on uterine inflammation during preterm labour

PubMed Central

Nakano, Tomoko; Kotani, Tomomi; Imai, Kenji; Iitani, Yukako; Ushida, Takafumi; Tsuda, Hiroyuki; Li, Hua; Iwase, Akira; Toyokuni, Shinya; Kikkawa, Fumitaka

2018-01-01

Intrauterine inflammation causes preterm birth and is associated with complications in preterm neonates. Thus, strategies aimed at suppressing inflammation are expected to be effective for reducing the risk of preterm birth and associated complications. Our previous studies demonstrated that molecular hydrogen (H2), an anti-inflammatory agent, prevented inflammation-induced impairment in foetal brain and lung tissues in lipopolysaccharide (LPS)-induced rodent models. However, it remains unclear whether H2 is capable of inhibiting preterm labour. The aim of the current study was therefore to investigate the effect of H2 on inflammation-induced preterm labour. Pregnant ICR (CD-1) mice were divided into three groups: Control, LPS and H2 water (HW) + LPS. In the control and LPS groups, vehicle and LPS, respectively, were intraperitoneally injected on embryonic day 15.5. In the HW + LPS group, HW was administered 24 h prior to LPS injection. The time from LPS administration to parturition was compared between the LPS and HW + LPS groups. Maternal uterus was collected 6 h after LPS injection and the transcript levels of pro-inflammatory cytokines, contractile-associated proteins (CAPs), matrix metalloproteinase-3 (Mmp3) and endothelin-1 (Et1) were assessed by reverse transcription-quantitative polymerase chain reaction. The protein levels of cyclooxygenase-2 (Cox2) were also evaluated by immunohistochemistry. The time from LPS administration to parturition in the HW + LPS group was significantly increased compared with that in the LPS group (33.5±3.4 vs. 18.3±8.8 h, respectively, P=0.020). H2 administration also resulted in significantly higher progesterone levels compared with LPS treatment alone (P=0.002). The transcript levels of pro-inflammatory cytokines, CAPs, Mmp3 and Et1 in the uteri of the LPS group were significantly higher than those in the control group (all P<0.05). In turn, all these levels with the exception of interleukin-8 and Mmp3 were significantly lower in the HW + LPS group compared with those in the LPS group (all P<0.05). The protein levels of Cox2 in the LPS group were also significantly increased compared with those in the control (P<0.001) and HW + LPS (P=0.003) groups. These results suggest that inflammation-induced changes in the uterus may be ameliorated through maternal H2 administration. Preventive H2 administration may therefore represent an effective strategy for the suppression of inflammation during preterm labour. PMID:29732148

Heat-tolerant versus heat-sensitive Bos taurus cattle: influence of air temperature and breed on the metabolic response to a provocative immune challenge.

PubMed

Burdick Sanchez, N C; Chaffin, R; Carroll, J A; Chase, C C; Coleman, S W; Spiers, D E

2013-11-01

The response of the immune and stress systems have been assessed in response to a lipopolysaccharide (LPS) challenge, yet the role of metabolism in mediating energy requirements during the acute phase response has not been sufficiently studied. This study tested heat-tolerant (Romosinuano [RO]) and heat-sensitive (Angus [ANG]) Bos taurus breeds at different ambient temperatures (Ta) to determine differential metabolic responses to LPS challenge. Twenty-one heifers (ANG: n = 11, 306 ± 26 kg BW; RO: n = 10, 313 ± 32 kg BW) were housed in stanchions in 4 temperature-controlled chambers. Initially, Ta in all 4 chambers was cycling at thermoneutrality (TN; 18.5°C-23.5°C) for a 1-wk adjustment period, followed by an increase in 2 chambers to cycling heat stress (HS; 24°C-38°C) for 2 wk. Five ANG and 5 RO heifers were housed at TN, whereas 6 ANG and 5 RO heifers were housed at HS. On day 19, heifers were fitted with jugular catheters. On day 20, heifers were challenged with LPS (0.5 μg/kg BW; 0 h), and blood samples were collected from -2 to 8 h and at 24 h relative to LPS challenge. Serum was analyzed for glucose, insulin, and NEFA concentrations. In addition, feed intake was measured 3 d before and on the day of the challenge. Feed intake decreased over time (P < 0.001) and was decreased in heifers housed at HS compared with heifers housed at TN (P = 0.013). Glucose concentrations before LPS challenge were greater in RO (P = 0.01) than in ANG heifers and greater in TN-housed heifers (P = 0.02) than in HS heifers. Glucose after LPS challenge initially increased before decreasing below baseline concentrations (P < 0.01) in all heifers. In addition, there was a breed by Ta interaction (P < 0.004), such that HS decreased glucose concentrations in ANG heifers compared with ANG heifers housed at TN (P < 0.001), whereas HS did not affect glucose concentrations after LPS challenge in RO heifers (P = 0.941). Nonesterified fatty acid concentrations before LPS challenge were not affected by breed (P = 0.37) or Ta (P = 0.60). Although NEFA concentration after LPS challenge was unaffected by Ta (P = 0.78), there tended to be a breed by Ta interaction (P = 0.07) such that, when housed at HS, RO heifers had greater serum NEFA concentrations after LPS challenge than ANG heifers (P = 0.009). Insulin concentration before LPS challenge was greater in RO heifers than in ANG heifers (P < 0.01). Insulin after LPS challenge increased (P < 0.01), with RO heifers producing a greater insulin response than ANG heifers (P < 0.01). These data suggest that HS decreases the metabolic response of heat-sensitive ANG heifers in response to LPS challenge, thus providing physiological evidence that may explain differences observed in the acute phase response between heat-sensitive ANG and heat-tolerant RO cattle breeds. Published by Elsevier Inc.

Modulation of lipopolysaccharide-induced chorioamnionitis in fetal sheep by maternal betamethasone.

PubMed

Wolfe, Katherine B; Snyder, Candice C; Gisslen, Tate; Kemp, Matthew W; Newnham, John P; Kramer, Boris W; Jobe, Alan H; Kallapur, Suhas

2013-12-01

We tested the hypothesis that the order of exposure to maternal betamethasone and intra-amniotic (IA) lipopolysaccharide (LPS) will differentially modulate inflammation in the chorioamnion. Time-mated Merino ewes with singleton fetuses received saline alone, IA LPS alone, maternal betamethasone before LPS, or betamethasone after LPS. We assessed inflammatory markers in the chorioamnion and the amniotic fluid. Inflammatory cell infiltration, expression of myeloperoxidase, serum amyloid A3 (acute phase reactant) in the chorioamnion, and levels of interleukin (IL)-8 in the amniotic fluid increased 7 days after LPS exposure. Betamethasone prior to LPS decreased infiltration of the inflammatory cells, CD3+ T cells, and decreased the levels of IL-1β and IL-8 in the amniotic fluid. Betamethasone 7 days prior to LPS exposure suppressed LPS-induced inflammation. The markers of inflammation largely had returned to the baseline 14 days after LPS exposure.

Lipopolysaccharide-reactive immunoglobulin E is associated with lower mortality and organ failure in traumatically injured patients.

PubMed Central

DiPiro, J T; Hamilton, R G; Howdieshell, T R; Adkinson, N F; Mansberger, A R

1994-01-01

Antilipopolysaccharide (anti-LPS) immunoglobulin G (IgG) and IgM have been associated with protection from LPS effects in vivo. We investigated the presence of IgE and anti-LPS in 32 patients that had experienced severe traumatic injury and in 35 healthy volunteers; we also investigated whether IgE anti-LPS was associated with important clinical events. Plasma samples were collected daily from patients in the intensive care unit and on one occasion from volunteers; the samples were assayed for IgE anti-LPS. IgE anti-LPS was assayed by enzyme-linked immunosorbent assay with monoclonal anti-human IgE as the capture antibody. Detection was accomplished with biotin-labeled LPS (Escherichia coli J5 mutant) followed by streptavidin-peroxidase with 2,2'-azino(3-ethylbenzthiazoline)sulfonic acid as the substrate. The assay was demonstrated to be specific for IgE and LPS-biotin by nonreactivity of control sera with high-titer anti-LPS IgG and IgM and by inhibition with unlabeled LPS. IgE anti-LPS was detected in 1 of 35 healthy controls (2.9%) and 25 of 32 traumatically injured patients (78%) (P < 0.001). The presence of IgE anti-LPS was associated with a lower incidence of death (P = 0.026) and of renal failure (P = 0.0012). There was no apparent temporal relationship between detection of IgE anti-LPS and clinical events. IgG anti-LPS was detected more frequently in patients that were positive for IgE anti-LPS (P = 0.06) but was not associated with clinical events. The inability to detect IgE anti-LPS may be related to adverse clinical events through depletion of specific IgE due to LPS exposure after trauma or through saturation of the assay by IgE with other specificities. We have reported increased total IgE concentrations in these patients. (J.T. DiPiro, R.G. Hamilton, T. R. Howdieshell, N. F. Adkinson, and A. R. Mansberger, Ann. Surg. 215:460-466, 1992). PMID:7496965

Glucocorticoid combined with hyaluronic acid enhance glucocorticoid receptor activity through inhibiting p-38MAPK signal pathway activation in treating acute lung injury in rats.

PubMed

Lv, Q

2016-09-01

In order to seek an effective strategy for clinical treatment of acute lung injury (ALI), we are committed to explore the effect of combination therapy of glucocorticoid and hyaluronic acid on acute lung injury caused by an endotoxin (LPS) and its mechanism. Adult male Sprague-Dawley (SD) rats were divided randomly into 5 groups: normal group (n=8); LPS group (n=8); dexamethasone +LPS group (DXMS group, n=8); hyaluronic acid+ LPS group (HA group, n=8); dexamethasone +hyaluronic acid +LPS group (DXMS+HA group, n=8). Firstly, SD rat model with acute lung injury induced by LPS was established, and injected corresponding drugs according to the plan. Then, the expression of TNF-a, IL-8, IL-10, ICAM-1 and total protein were measured by ELISA, and the HE staining was used for detected the pathological change in lung tissue. Subsequently, the water content, dry and wet ratio and permeability in lung tissues of SD rats was assayed. Finally, the expression level of the glucocorticoid receptor (GR) was detected by RT-PCR, and activation of p-p38MAPK was determined by Western blotting. The results showed that concentration of IL-8, IL-10 and ICAM-1 was significantly increased in BALF after LPS injection, and the results from HE staining showed it had widespread inflammation. However, lung structures in SD rats with inhalation lung injury were improved significantly after the injection of dexamethasone and hyaluronic acid, and the Pa02/Fi02, blood pressure and Cdyn were also increased. Moreover, lung water content, the ratio of wet and dry lung, and lung permeability index (LPI) was decreased after having treated the SD rats with a combination of dexamethasone and hyaluronic acid, and the apoptosis index was also decreased in the rats with LPS-induced ALI. Our data also suggested that TNF-α, IL-8, IL-10, intercellular cell adhesion molecule-1 (ICAM-1) and total protein was significantly declined in bronchoalveolar lavage fluid (BALF) of rats with LPS-induced acute lung injury after treated the SD rats with a combination of dexamethasone and hyaluronic acid. In addition, the data also implied that anti-inflammatory effect by inhibiting the activation of p38MAPK signal pathway induced by LPS through enhancement of the activity of GR, to further analyze the mechanism of the effect of combination therapy with dexamethasone and hyaluronic acid on acute lung injury in SD rats. LPS-induced ALI in SD rats is relieved after treatment with a combination of dexamethasone and hyaluronic acid. In the process of its function, activated GR can represent anti-inflammatory effect and protect the lung tissue by inhibiting the activation/phosphorylation of p38MAPK, while hyaluronic acid can enhance micro-environment of alveolar tissue.

Angiopoietin-like protein 2 regulates Porphyromonas gingivalis lipopolysaccharide-induced inflammatory response in human gingival epithelial cells.

PubMed

Ohno, Tasuku; Yamamoto, Genta; Hayashi, Jun-Ichiro; Nishida, Eisaku; Goto, Hisashi; Sasaki, Yasuyuki; Kikuchi, Takeshi; Fukuda, Mitsuo; Hasegawa, Yoshiaki; Mogi, Makio; Mitani, Akio

2017-01-01

Angiopoietin-like protein 2 (ANGPTL2) maintains tissue homeostasis by inducing inflammation and angiogenesis. It is produced in infiltrating immune cells or resident cells, such as adipocytes, vascular endothelial cells, and tumor cells. We hypothesized that ANGPTL2 might play an important role as a unique mediator in both systemic and periodontal disease. We demonstrated an increased ANGPTL2 concentration in gingival crevicular fluid from chronic periodontitis patients. Porphyromonas gingivalis lipopolysaccharide (LPS) treatment strongly induced ANGPTL2 mRNA and protein levels in Ca9-22 human gingival epithelial cells. Recombinant human ANGPTL2 increased interleukin 1β (IL-1β), IL-8, and tumor necrosis factor-α (TNF-α) mRNA and protein levels in Ca9-22 cells. Small-interfering (si)RNA-mediated ANGPTL2 knockdown in Ca9-22 cells reduced IL-1β, IL-8 and TNF-α mRNA and protein levels compared with control siRNA (p<0.01) in P. gingivalis LPS-stimulated Ca9-22 cells. Antibodies against integrin α5β1, an ANGPTL receptor, blocked induction of these inflammatory cytokines in P. gingivalis LPS-treated Ca9-22 cells, suggesting that secreted ANGPTL induces inflammatory cytokines in gingival epithelial cells via an autocrine loop. The classic sequential cascade of P. gingivalis LPS → inflammatory cytokine induction is well established. However, in the current study, we reveal a novel cascade comprising sequential P. gingivalis LPS → ANGPTL2 → integrin α5β1 → inflammatory cytokine induction, which might be responsible for inducing potent periodontal disorganization activity in gingival epithelial cells. Via this pathway, ANGPTL2 functions in the pathogenesis of periodontitis and contributes to prolonging chronic inflammation in patients with systemic disease.

Angiopoietin-like protein 2 regulates Porphyromonas gingivalis lipopolysaccharide-induced inflammatory response in human gingival epithelial cells

PubMed Central

Ohno, Tasuku; Hayashi, Jun-ichiro; Nishida, Eisaku; Goto, Hisashi; Sasaki, Yasuyuki; Kikuchi, Takeshi; Fukuda, Mitsuo; Hasegawa, Yoshiaki; Mogi, Makio; Mitani, Akio

2017-01-01

Angiopoietin-like protein 2 (ANGPTL2) maintains tissue homeostasis by inducing inflammation and angiogenesis. It is produced in infiltrating immune cells or resident cells, such as adipocytes, vascular endothelial cells, and tumor cells. We hypothesized that ANGPTL2 might play an important role as a unique mediator in both systemic and periodontal disease. We demonstrated an increased ANGPTL2 concentration in gingival crevicular fluid from chronic periodontitis patients. Porphyromonas gingivalis lipopolysaccharide (LPS) treatment strongly induced ANGPTL2 mRNA and protein levels in Ca9-22 human gingival epithelial cells. Recombinant human ANGPTL2 increased interleukin 1β (IL-1β), IL-8, and tumor necrosis factor-α (TNF-α) mRNA and protein levels in Ca9-22 cells. Small-interfering (si)RNA-mediated ANGPTL2 knockdown in Ca9-22 cells reduced IL-1β, IL-8 and TNF-α mRNA and protein levels compared with control siRNA (p<0.01) in P. gingivalis LPS-stimulated Ca9-22 cells. Antibodies against integrin α5β1, an ANGPTL receptor, blocked induction of these inflammatory cytokines in P. gingivalis LPS-treated Ca9-22 cells, suggesting that secreted ANGPTL induces inflammatory cytokines in gingival epithelial cells via an autocrine loop. The classic sequential cascade of P. gingivalis LPS → inflammatory cytokine induction is well established. However, in the current study, we reveal a novel cascade comprising sequential P. gingivalis LPS → ANGPTL2 → integrin α5β1 → inflammatory cytokine induction, which might be responsible for inducing potent periodontal disorganization activity in gingival epithelial cells. Via this pathway, ANGPTL2 functions in the pathogenesis of periodontitis and contributes to prolonging chronic inflammation in patients with systemic disease. PMID:28934245

Selective decontamination of the digestive tract ameliorates severe burn-induced insulin resistance in rats.

PubMed

Li, Jun; Zhu, Liang; Xu, Ming; Han, Juntao; Bai, Xiaozhi; Yang, Xuekang; Zhu, Huayu; Xu, Jie; Zhang, Xing; Gong, Yangfan; Hu, Dahai; Gao, Feng

2015-08-01

Severe burns often initiate the prevalence of hyperglycemia and insulin resistance, significantly contributing to adverse clinical outcomes. However, there are limited treatment options. This study was designed to investigate the role and the underlying mechanisms of oral antibiotics to selectively decontaminate the digestive tract (SDD) on burn-induced insulin resistance. Rats were subjected to 40% of total body surface area full-thickness burn or sham operation with or without SDD treatment. Translocation of FITC-labeled LPS was measured at 4h after burn. Furthermore, the effect of SDD on post-burn quantity of gram-negative bacteria in gut was investigated. Serum or muscle LPS and proinflammatory cytokines were measured. Intraperitoneal glucose tolerance test and insulin tolerance test were used to determine the status of systemic insulin resistance. Furthermore, intracellular insulin signaling (IRS-1 and Akt) and proinflammatory related kinases (JNK and IKKβ) were assessed by western blot. Burn increased the translocation of LPS from gut 4h after injury. SDD treatment effectively inhibited post-burn overgrowth of gram-negative enteric bacilli in gut. In addition, severe burns caused significant increases in the LPS and proinflammatory cytokines levels, activation of proinflammatory related kinases, and systemic insulin resistance as well. But SDD treatment could significantly attenuate burn-induced insulin resistance and improve the whole-body responsiveness to insulin, which was associated with the inhibition of gut-derived LPS, cytokines, proinflammatory related kinases JNK and IKKβ, as well as activation of IRS-1 and Akt. SDD appeared to have an effect on proinflammatory signaling cascades and further reduced severe burn-induced insulin resistance. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

Endocannabinergic modulation of interleukin-1β in mouse hippocampus under basal conditions and after in vivo systemic lipopolysaccharide stimulation.

PubMed

Csölle, Cecília; Sperlágh, Beáta

2011-01-01

Cannabinoids play an important role in the suppression of proinflammatory cytokine production in the periphery and brain. In this study, we explored whether endogenous activation of cannabinoid (CB) 1 receptors (CB1Rs) affects interleukin (IL)-1β levels in the mouse hippocampus under basal conditions and following stimulation with in vivo bacterial lipopolysaccharide (LPS, 250 μg/kg i.p.). IL-1β levels were determined in the hippocampi of wild-type (WT), CB1R-/- and P2X₇ receptor (P2X₇R)-/- mice using an ELISA kit. Basal but not LPS-induced IL-1β levels were downregulated when CB1R function was abrogated by genetic deletion, suggesting that endocannabinoids contributed to basal IL-1β content in the mouse hippocampus. AM251 (3 mg/kg i.p.), an antagonist of CB1Rs, also inhibited basal IL-1β protein in WT but not in CB1R-/- mice. In the absence of P2X₇R, LPS-induced IL-1β production was lower, while the inhibitory effect of CB1R antagonists on basal IL-1β was significantly attenuated. The LPS-induced elevation in IL-1β production was decreased in the presence of AM251 and AM281, with no significant difference between WT and P2X₇R-/- mice. CB1Rs are responsible for the modulation of basal IL-1β levels in the hippocampus, while the effects of CB1 antagonists on systemic LPS-induced IL-1β concentrations are independent of CB1Rs. Copyright © 2011 S. Karger AG, Basel.

Acute exposure to cadmium induces prolonged neutrophilia along with delayed induction of granulocyte colony-stimulating factor in the livers of mice.

PubMed

Horiguchi, Hyogo; Oguma, Etsuko

2016-12-01

Acute exposure to cadmium (Cd), a toxic heavy metal, causes systemic inflammation characterized by neutrophilia. To elucidate the mechanism of neutrophilia induced by Cd, we investigated the induction of granulocyte colony-stimulating factor (G-CSF), which regulates neutrophil production, in mice with acute Cd toxicity, and compared it with mice injected with lipopolysaccharide (LPS) as an inducer of general inflammatory responses. We injected BALB/c mice with Cd at 2.5 mg/kg i.p. or LPS at 0.5 mg/kg i.p. and sampled the peripheral blood and organs at time points up to 24 h. In Cd-treated mice, the peripheral neutrophil count increased steadily up to 24 h, whereas LPS-treated mice showed a more rapid increase with a peak at 12 h. The serum G-CSF level increased gradually to reach a plateau at 12-18 h in Cd-treated mice, but LPS-treated mice showed a marked increase, reaching a peak at 2-3 h. A gradual elevation of G-CSF mRNA expression up to 24 h was detected by real-time PCR in the livers of Cd-treated mice, but in LPS-treated mice its highest expression was observed in the liver with a rapid increase at 2 h. By in situ hybridization using G-CSF RNA probes, hepatic Kupffer cells were identified as G-CSF-producing cells in the liver. These results indicated that Cd has a characteristic effect of delayed induction of G-CSF in the liver, causing systemic inflammation accompanied by prolonged neutrophilia.

Establishing a preoperative evaluation system for lumboperitoneal shunt: Approach to attenuate the risk of shunt failure.

PubMed

Sun, Tong; Yuan, Yikai; Zhang, Qiuming; Zhou, Yicheng; Li, Xuepei; Yu, Hang; Tian, Meng; Guan, Junwen

2018-06-12

Lumboperitoneal shunt (LPS) has been demonstrated an effective method for the treatment of communicating hydrocephalus in the presence of frequent shunt failure. To determine if establishing a preoperative evaluation system could benefit patients thus attenuating the risk of LPS failure. In this three-year study, treated by LPS, patients undergoing preoperative evaluation were included into study group and others without preoperative evaluation were included into control group. Perioperative conditions, including Keifer's hydrocephalus score (KHS), symptomatic control rate (SCR), Evans index, complications, long-term shunt revision rate, and quality of life (QOL), were synchronously investigated. 93 eligible patients were included in the study (study group: 51, control group: 42). The baseline characteristics of two groups were basically similar. The results showed patients in study group had better short-term improvement in symptoms and imageology, including higher SCR (Median, 62.5% vs 50%, P=0.001), more reduction in Evans index (0.08±0.05 vs 0.05±0.04, P=0.002), and lower incidence of postoperative complications (Median, 35.3% vs 57.1%, P=0.04). Similarly, the incidence of shunt revision in study group was dramatically lower than control group (Median, 15.7% vs 40.9%, P=0.006) in line with the revision-free curve (P=0.002), in which suggested most of patients received revision, if needed, within 3 months. Additionally, patients in study group had better QOL. In conclusion, patients who underwent the evaluation before LPS had better short-term and long-term outcomes, suggesting it would be a promising strategy to correctly select patients for LPS with prolonged favorable shunt outcomes. Copyright © 2018 Elsevier Inc. All rights reserved.

Effects of Ozone Oxidative Preconditioning on TNF-α Release and Antioxidant-Prooxidant Intracellular Balance in Mice During Endotoxic Shock

PubMed Central

Zamora, Zullyt B.; Borrego, Aluet; López, Orlay Y.; Delgado, René; González, Ricardo; Menéndez, Silvia; Hernández, Frank; Schulz, Siegfried

2005-01-01

Ozone oxidative preconditioning is a prophylactic approach, which favors the antioxidant-prooxidant balance for preservation of cell redox state by the increase of antioxidant endogenous systems in both in vivo and in vitro experimental models. Our aim is to analyze the effect of ozone oxidative preconditioning on serum TNF-α levels and as a modulator of oxidative stress on hepatic tissue in endotoxic shock model (mice treated with lipopolysaccharide (LPS)). Ozone/oxygen gaseous mixture which was administered intraperitoneally (0.2, 0.4, and 1.2 mg/kg) once daily for five days before LPS (0.1 mg/kg, intraperitoneal). TNF-α was measured by cytotoxicity on L-929 cells. Biochemical parameters such as thiobarbituric acid reactive substances (TBARS), enzymatic activity of catalase, glutathione peroxidase, and glutathione-S transferase were measured in hepatic tissue. One hour after LPS injection there was a significant increase in TNF-α levels in mouse serum. Ozone/oxygen gaseous mixture reduced serum TNF-α levels in a dose-dependent manner. Statistically significant decreases in TNF-α levels after LPS injection were observed in mice pretreated with ozone intraperitoneal applications at 0.2 (78%), 0.4 (98%), and 1.2 (99%). Also a significant increase in TBARS content was observed in the hepatic tissue of LPS-treated mice, whereas enzymatic activity of glutathion-S transferase and glutathione peroxidase was decreased. However in ozone-treated animals a significant decrease in TBARS content was appreciated as well as an increase in the activity of antioxidant enzymes. These results indicate that ozone oxidative preconditioning exerts inhibitory effects on TNF-α production and on the other hand it exerts influence on the antioxidant-prooxidant balance for preservation of cell redox state by the increase of endogenous antioxidant systems. PMID:15770062

Fluocinolone acetonide partially restores the mineralization of LPS-stimulated dental pulp cells through inhibition of NF-κB pathway and activation of AP-1 pathway

PubMed Central

Liu, Zhongning; Jiang, Ting; Wang, Xinzhi; Wang, Yixiang

2013-01-01

BACKGROUND AND PURPOSE Fluocinolone acetonide (FA) is commonly used as a steroidal anti-inflammatory drug. We recently found that in dental pulp cells (DPCs) FA has osteo-/odonto-inductive as well as anti-inflammatory effects. However, the mechanism by which FA induces these effects in DPCs is poorly understood. EXPERIMENTAL APPROACH The effect of FA on the mineralization of DPCs during inflammatory conditions and the underlying mechanism were investigated by real-time PCR, Western blot, EMSA, histochemical staining, immunostaining and pathway blockade assays. KEY RESULTS FA significantly inhibited the inflammatory response in LPS-treated DPCs not only by down-regulating the expression of pro–inflammation-related genes, but also by up-regulating the expression of the anti-inflammatory gene PPAR-γ and mineralization-related genes. Moreover, histochemical staining and immunostaining showed that FA could partially restore the expressions of alkaline phosphatase, osteocalcin and dentin sialophosphoprotein (DSPP) and mineralization in LPS-stimulated DPCs. Real-time PCR and Western blot analysis revealed that FA up-regulated DSPP and runt-related transcription factor 2 expression by inhibiting the expression of phosphorylated-NF-κB P65 and activating activator protein-1 (AP-1) (p-c-Jun and Fra-1). These results were further confirmed through EMSA, by detection of NF-κB DNA-binding activity and pathway blockade assays using a NF-κB pathway inhibitor, AP-1 pathway inhibitor and glucocorticoid receptor antagonist. CONCLUSIONS AND IMPLICATIONS Inflammation induced by LPS suppresses the mineralization process in DPCs. FA partially restored this osteo-/odonto-genesis process in LPS-treated DPCs and had an anti-inflammatory effect through inhibition of the NF-κB pathway and activation of the AP-1 pathway. Hence, FA is a potential new treatment for inflammation-associated bone/teeth diseases. PMID:24024985

DNA methylcytosine dioxygenase ten-eleven translocation 2 enhances lipopolysaccharide-induced cytokine expression in human dental pulp cells by regulating MyD88 hydroxymethylation.

PubMed

Wang, Xinxuan; Feng, Zhihui; Li, Qimeng; Yi, Baicheng; Xu, Qiong

2018-04-13

Dental pulp inflammation is a bacterially driven inflammation process characterized by the local accumulation of cytokines/chemokines that participate in destructive processes in the pulp. Multiple mechanisms are involved in dental pulp inflammation, including epigenetic events, such as DNA methylation/demethylation. Ten-eleven translocation 2 (TET2) is a recently discovered DNA methylcytosine dioxygenase that plays important roles in inflammatory disease. However, its role in the inflammatory response of dental pulp is unknown. We observed elevated mRNA and protein levels of TET2 after lipopolysaccharide (LPS) stimulation in human dental pulp cells (hDPCs). To identify the effects of TET2 on cytokine expression, TET2 was knocked down and cytokines were detected using a cytokine antibody array after LPS stimulation. The protein expression of GM-CSF, IL-6, IL-8 and RANTES decreased in the LPS-induced hDPCs following TET2 knockdown. The downregulated expression levels of IL-6 and IL-8 were further confirmed by real-time quantitative polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA). Additionally, the phosphorylation levels of IKK-α/β, p65 and IκBα of the NF-κB signaling pathway were decreased in the TET2-silenced group. Furthermore, the global 5-hydroxymethylcytosine (5hmC) level was significantly decreased and the genomic 5-methylcytosine (5mC) level was increased in the TET2-deficient hDPCs; TET2 depletion resulted in a decrease in the 5hmC level of the MyD88 promoter following LPS stimulation. These findings indicate that TET2 knockdown inhibits LPS-induced inflammatory response in hDPCs by downregulating MyD88 hydroxymethylation. Thus, TET2-dependent DNA demethylation might play an important role in dental pulp inflammation as an epigenetic regulator.

Cyanobacterial lipopolysaccharides and human health – a review

PubMed Central

Stewart, Ian; Schluter, Philip J; Shaw, Glen R

2006-01-01

Cyanobacterial lipopolysaccharide/s (LPS) are frequently cited in the cyanobacteria literature as toxins responsible for a variety of heath effects in humans, from skin rashes to gastrointestinal, respiratory and allergic reactions. The attribution of toxic properties to cyanobacterial LPS dates from the 1970s, when it was thought that lipid A, the toxic moiety of LPS, was structurally and functionally conserved across all Gram-negative bacteria. However, more recent research has shown that this is not the case, and lipid A structures are now known to be very different, expressing properties ranging from LPS agonists, through weak endotoxicity to LPS antagonists. Although cyanobacterial LPS is widely cited as a putative toxin, most of the small number of formal research reports describe cyanobacterial LPS as weakly toxic compared to LPS from the Enterobacteriaceae. We systematically reviewed the literature on cyanobacterial LPS, and also examined the much lager body of literature relating to heterotrophic bacterial LPS and the atypical lipid A structures of some photosynthetic bacteria. While the literature on the biological activity of heterotrophic bacterial LPS is overwhelmingly large and therefore difficult to review for the purposes of exclusion, we were unable to find a convincing body of evidence to suggest that heterotrophic bacterial LPS, in the absence of other virulence factors, is responsible for acute gastrointestinal, dermatological or allergic reactions via natural exposure routes in humans. There is a danger that initial speculation about cyanobacterial LPS may evolve into orthodoxy without basis in research findings. No cyanobacterial lipid A structures have been described and published to date, so a recommendation is made that cyanobacteriologists should not continue to attribute such a diverse range of clinical symptoms to cyanobacterial LPS without research confirmation. PMID:16563160

Chamomile, a novel and selective COX-2 inhibitor with anti-inflammatory activity

PubMed Central

Srivastava, Janmejai K; Pandey, Mitali; Gupta, Sanjay

2009-01-01

Aims Inducible cyclooxygenase (COX-2) has been implicated in the process of inflammation and carcinogenesis. Chamomile has long been used in traditional medicine for the treatment of inflammatory diseases. In this study we aimed to investigate whether chamomile interferes with the COX-2 pathway. Main Methods We used lipopolysaccharide (LPS)-activated RAW 264.7 macrophages as an in vitro model for our studies. Key Findings Chamomile treatment inhibited the release of LPS-induced prostaglandin E(2) in RAW 264.7 macrophages. This effect was found to be due to inhibition of COX-2 enzyme activity by chamomile. In addition, chamomile caused reduction in LPS-induced COX-2 mRNA and protein expression, without affecting COX-1 expression. The non-steroidal anti-inflammatory drug, sulindac and a specific COX-2 inhibitor, NS398, were shown to act similarly in LPS-activated RAW 264.7 cells. Our data suggest that chamomile works by a mechanism of action similar to that attributed to non-steroidal anti-inflammatory drugs. Significance These findings add a novel aspect to the biological profile of chamomile which might be important for understanding the usefulness of aqueous chamomile extract in the form of tea in preventing inflammation and cancer. PMID:19788894

Chamomile, a novel and selective COX-2 inhibitor with anti-inflammatory activity.

PubMed

Srivastava, Janmejai K; Pandey, Mitali; Gupta, Sanjay

2009-11-04

Inducible cyclooxygenase (COX-2) has been implicated in the process of inflammation and carcinogenesis. Chamomile has long been used in traditional medicine for the treatment of inflammatory diseases. In this study we aimed to investigate whether chamomile interferes with the COX-2 pathway. We used lipopolysaccharide (LPS)-activated RAW 264.7 macrophages as an in vitro model for our studies. Chamomile treatment inhibited the release of LPS-induced prostaglandin E(2) in RAW 264.7 macrophages. This effect was found to be due to inhibition of COX-2 enzyme activity by chamomile. In addition, chamomile caused reduction in LPS-induced COX-2 mRNA and protein expression, without affecting COX-1 expression. The non-steroidal anti-inflammatory drug, sulindac and a specific COX-2 inhibitor, NS398, were shown to act similarly in LPS-activated RAW 264.7 cells. Our data suggest that chamomile works by a mechanism of action similar to that attributed to non-steroidal anti-inflammatory drugs. These findings add a novel aspect to the biological profile of chamomile which might be important for understanding the usefulness of aqueous chamomile extract in the form of tea in preventing inflammation and cancer.

Endotoxin-induced nitric oxide production rescues airway growth and maturation in atrophic fetal rat lung explants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rae, C.; Cherry, J.I.; Land, F.M.

Inflammation induces premature maturation of the fetal lung but the signals causing this effect remain unclear. We determined if nitric oxide (NO) synthesis, evoked by Escherichia coli lipopolysaccharide (LPS, 2 {mu}g ml{sup -1}), participated in this process. Fetal rat lung airway surface complexity rose 2.5-fold over 96 h in response to LPS and was associated with increased iNOS protein expression and activity. iNOS inhibition by N6-(1-iminoethyl)-L-lysine-2HCl (L-NIL) abolished this and induced airway atrophy similar to untreated explants. Surfactant protein-C (SP-C) expression was also induced by LPS and abolished by L-NIL. As TGF{beta} suppresses iNOS activity, we determined if feedback regulationmore » modulated NO-dependent maturation. LPS induced TGF{beta}1 release and SMAD4 nuclear translocation 96 h after treatment. Treatment of explants with a blocking antibody against TGF{beta}1 sustained NO production and airway morphogenesis whereas recombinant TGF{beta}1 antagonized these effects. Feedback regulation of NO synthesis by TGF{beta} may, thus, modulate airway branching and maturation of the fetal lung.« less

Cannabidiol improves lung function and inflammation in mice submitted to LPS-induced acute lung injury.

PubMed

Ribeiro, A; Almeida, V I; Costola-de-Souza, C; Ferraz-de-Paula, V; Pinheiro, M L; Vitoretti, L B; Gimenes-Junior, J A; Akamine, A T; Crippa, J A; Tavares-de-Lima, W; Palermo-Neto, J

2015-02-01

We have previously shown that the prophylactic treatment with cannabidiol (CBD) reduces inflammation in a model of acute lung injury (ALI). In this work we analyzed the effects of the therapeutic treatment with CBD in mice subjected to the model of lipopolysaccharide (LPS)-induced ALI on pulmonary mechanics and inflammation. CBD (20 and 80 mg/kg) was administered (i.p.) to mice 6 h after LPS-induced lung inflammation. One day (24 h) after the induction of inflammation the assessment of pulmonary mechanics and inflammation were analyzed. The results show that CBD decreased total lung resistance and elastance, leukocyte migration into the lungs, myeloperoxidase activity in the lung tissue, protein concentration and production of pro-inflammatory cytokines (TNF and IL-6) and chemokines (MCP-1 and MIP-2) in the bronchoalveolar lavage supernatant. Thus, we conclude that CBD administered therapeutically, i.e. during an ongoing inflammatory process, has a potent anti-inflammatory effect and also improves the lung function in mice submitted to LPS-induced ALI. Therefore the present and previous data suggest that in the future cannabidiol might become a useful therapeutic tool for the attenuation and treatment of inflammatory lung diseases.

Withaferin A Inhibits Nuclear Factor-κB-Dependent Pro-Inflammatory and Stress Response Pathways in the Astrocytes.

PubMed

Martorana, Francesca; Guidotti, Giulia; Brambilla, Liliana; Rossi, Daniela

2015-01-01

Several lines of evidence suggest that astrocytes play a key role in modulating the immune responses of the central nervous system (CNS) to infections, injuries, or pathologies. Yet, their contribution to these processes remains mostly elusive. Astroglia are endowed with a wide range of toll-like receptors (TLR) by which they can sense infectious agents as well as endogenous danger signals released by damaged cells. Here we demonstrate that the activation of astrocytic TLR4 by bacterial lipopolysaccharide (LPS) challenge can promote nuclear factor κB (NF-κB)-dependent induction of pro-inflammatory and stress response mediators, particularly Tumor Necrosis Factor α (TNFα), cyclooxygenase 2 (COX-2), and inducible nitric oxide synthase (iNOS). Since the steroid lactone Withaferin A was described to inhibit NF-κB activity in different cell types, we next determined the impact of this natural compound towards the identified astrocytic signalling pathway. Innate immune activation was induced by stimulation of the LPS/TLR4 axis in spinal cord astrocytes. We provide evidence that both pre-treating and post-treating the cells with Withaferin A attenuate astrocytic NF-κB activity as well as the consequent production of TNFα, COX-2, and iNOS induced by stimulation of the LPS/TLR4 pathway. This study suggests that Withaferin A may be an eligible candidate for the treatment of neuroinflammatory and stress conditions characterized by an important astrocytic input.

Withaferin A Inhibits Nuclear Factor-κB-Dependent Pro-Inflammatory and Stress Response Pathways in the Astrocytes

PubMed Central

Martorana, Francesca; Guidotti, Giulia; Brambilla, Liliana; Rossi, Daniela

2015-01-01

Several lines of evidence suggest that astrocytes play a key role in modulating the immune responses of the central nervous system (CNS) to infections, injuries, or pathologies. Yet, their contribution to these processes remains mostly elusive. Astroglia are endowed with a wide range of toll-like receptors (TLR) by which they can sense infectious agents as well as endogenous danger signals released by damaged cells. Here we demonstrate that the activation of astrocytic TLR4 by bacterial lipopolysaccharide (LPS) challenge can promote nuclear factor κB (NF-κB)-dependent induction of pro-inflammatory and stress response mediators, particularly Tumor Necrosis Factor α (TNFα), cyclooxygenase 2 (COX-2), and inducible nitric oxide synthase (iNOS). Since the steroid lactone Withaferin A was described to inhibit NF-κB activity in different cell types, we next determined the impact of this natural compound towards the identified astrocytic signalling pathway. Innate immune activation was induced by stimulation of the LPS/TLR4 axis in spinal cord astrocytes. We provide evidence that both pre-treating and post-treating the cells with Withaferin A attenuate astrocytic NF-κB activity as well as the consequent production of TNFα, COX-2, and iNOS induced by stimulation of the LPS/TLR4 pathway. This study suggests that Withaferin A may be an eligible candidate for the treatment of neuroinflammatory and stress conditions characterized by an important astrocytic input. PMID:26266054

Endotoxemia severely affects circulation during normoxia and asphyxia in immature fetal sheep.

PubMed

Garnier, Y; Coumans, A; Berger, R; Jensen, A; Hasaart, T H

2001-01-01

The purpose of the present study was to determine whether endotoxins (lipopolysaccharides, LPS) affect the fetal cardiovascular system in a way likely to cause brain damage. Thirteen fetal sheep were chronically instrumented at a mean gestational age of 107 +/- 1 days. After control measurements of organ blood flow (microsphere method), blood gases, and acid base balance were obtained, seven of 13 fetuses received LPS (53 +/- 3 microg/kg fetal weight) intravenously. Sixty minutes later, asphyxia was induced by occlusion of the maternal aorta for 2 minutes. Measurements of organ blood flows were made at -60, -1, +2, +4, +30, and +60 minutes. Unlike in the control group, after LPS infusion there was a significant decrease in arterial oxygen saturation (-46%; P <.001) and pH (P <.001). In LPS-treated fetuses the portion of combined ventricular output directed to the placenta decreased significantly (-76%; P <.001), whereas output to the fetal body (+60%; P <.001), heart (+167%; P <.05), and adrenals (+229%; P <.01) increased. Furthermore, during asphyxia circulatory centralization was impaired considerably in LPS-treated fetuses, and there was clear evidence of circulatory decentralization. This decentralization caused a severe decrease in cerebral oxygen delivery by 70%. Within 30 minutes after induction of asphyxia five of seven LPS-treated fetuses died, whereas all control fetuses recovered completely. Endotoxemia severely impaired fetal cardiovascular control during normoxia and asphyxia, resulting in a considerable decrease in cerebral oxygen delivery. These effects might have important effects in the development of fetal brain damage associated with intrauterine infection.

Cigarette smoke inhibits macrophage sensing of Gram-negative bacteria and lipopolysaccharide: relative roles of nicotine and oxidant stress

PubMed Central

McMaster, S K; Paul-Clark, M J; Walters, M; Fleet, M; Anandarajah, J; Sriskandan, S; Mitchell, J A

2007-01-01

Background and purpose: Smoking cigarettes is a major risk factor for the development of cardiovascular and respiratory disease. Moreover, smokers are more prone to infections. This has been associated with a suppression of the immune system by smoke. However, it is not clear how cigarette smoke affects the ability of immune cells to sense pathogens. Cigarette smoke contains a large number of molecules which may mediate responses on immune cells and of these, nicotine and oxidants have both been identified as inhibitory for the sensing of bacterial lipopolysaccharide (LPS). Nitric oxide synthase (NOS) and tumour necrosis factor (TNF)-α are both induced in macrophages on stimulation with Gram negative bacteria or LPS. Experimental approach: We used murine macrophages stimulated with whole heat-killed bacteria or LPS. We measured output of NO (as nitrite) and TNFα, NOS protein by Western blotting and cellular oxidant stress. Key results: Cigarette smoke extract suppressed the ability of murine macrophages to release NO, but not TNFα in response to whole bacteria. Cigarette smoke extract also inhibited nitric oxide synthase II protein expression in response to LPS. The effects of cigarette smoke extract on nitrite formation stimulated by LPS were unaffected by inhibition of nicotinic receptors with α-bungarotoxin (100 units ml−1). However, the effects of cigarette smoke extract on LPS-induced nitrite formation were mimicked by hydrogen peroxide and reversed by the anti-oxidants N-acetyl cysteine and glutathione. Conclusions and implications: We suggest that cigarette smoke exerts its immunosuppressive effects through an oxidant-dependent and not a nicotine-dependent mechanism. PMID:18059323

Voluntary Wheel Running Does not Affect Lipopolysaccharide-Induced Depressive-Like Behavior in Young Adult and Aged Mice

PubMed Central

Martin, Stephen A.; Dantzer, Robert; Kelley, Keith W.; Woods, Jeffrey A.

2014-01-01

Peripheral stimulation of the innate immune system with lipopolysaccharide (LPS) causes prolonged depressive-like behavior in aged mice that is dependent on indoleamine 2,3 dioxygenase (IDO) activation. Regular moderate intensity exercise training has been shown to exert neuroprotective effects that might reduce depressive-like behavior in aged mice. The purpose of this study was to test the hypothesis that voluntary wheel running would attenuate LPS-induced depressive-like behavior and brain IDO gene expression in 4-month-old and 22-month-old C57BL/6J mice. Mice were housed with a running wheel (Voluntary Wheel Running, VWR) or no wheel (Standard) for 30 days (young adult mice) or 70 days (aged mice), after which they were intraperitoneally injected with LPS (young adult mice: 0.83 mg/kg; aged mice: 0.33 mg/kg). Young adult VWR mice ran on average 6.9 km/day, while aged VWR mice ran on average 3.4 km/day. Both young adult and aged VWR mice increased their forced exercise tolerance compared to their respective Standard control groups. VWR had no effect on LPS-induced anorexia, weight-loss, increased immobility in the tail suspension test, and decreased sucrose preference in either young adult or aged mice. Four (young adult mice) and twenty-four (aged mice) hours after injection of LPS transcripts for TNF-α, IL-1β, IL-6, and IDO were upregulated in the whole brain independently of VWR. These results indicate that prolonged physical exercise has no effect on the neuroinflammatory response to LPS and its behavioral consequences. PMID:24281669

Cigarette smoke inhibits macrophage sensing of Gram-negative bacteria and lipopolysaccharide: relative roles of nicotine and oxidant stress.

PubMed

McMaster, S K; Paul-Clark, M J; Walters, M; Fleet, M; Anandarajah, J; Sriskandan, S; Mitchell, J A

2008-02-01

Smoking cigarettes is a major risk factor for the development of cardiovascular and respiratory disease. Moreover, smokers are more prone to infections. This has been associated with a suppression of the immune system by smoke. However, it is not clear how cigarette smoke affects the ability of immune cells to sense pathogens. Cigarette smoke contains a large number of molecules which may mediate responses on immune cells and of these, nicotine and oxidants have both been identified as inhibitory for the sensing of bacterial lipopolysaccharide (LPS). Nitric oxide synthase (NOS) and tumour necrosis factor (TNF)-alpha are both induced in macrophages on stimulation with Gram negative bacteria or LPS. We used murine macrophages stimulated with whole heat-killed bacteria or LPS. We measured output of NO (as nitrite) and TNFalpha, NOS protein by Western blotting and cellular oxidant stress. Cigarette smoke extract suppressed the ability of murine macrophages to release NO, but not TNFalpha in response to whole bacteria. Cigarette smoke extract also inhibited nitric oxide synthase II protein expression in response to LPS. The effects of cigarette smoke extract on nitrite formation stimulated by LPS were unaffected by inhibition of nicotinic receptors with alpha-bungarotoxin (100 units ml(-1)). However, the effects of cigarette smoke extract on LPS-induced nitrite formation were mimicked by hydrogen peroxide and reversed by the anti-oxidants N-acetyl cysteine and glutathione. We suggest that cigarette smoke exerts its immunosuppressive effects through an oxidant-dependent and not a nicotine-dependent mechanism.

Characterization of Differential Toll-Like Receptor Responses below the Optical Diffraction Limit**

PubMed Central

Aaron, Jesse S.; Carson, Bryan D.; Timlin, Jerilyn A.

2013-01-01

Many membrane receptors are recruited to specific cell surface domains to form nanoscale clusters upon ligand activation. This step appears to be necessary to initiate signaling, including pathways in innate immune system activation. However, virulent pathogens such as Yersinia pestis (the causative agent of plague) are known to evade innate immune detection, in contrast to similar microbes (such as E. coli) that elicit a robust response. This disparity has been partly attributed to the structure of lipopolysaccharides (LPS) on the bacterial cell wall, which are recognized by the innate immune receptor TLR4. As such, we hypothesized that nanoscale differences would exist between the spatial clustering of TLR4 upon binding of LPS derived from Y. pestis and E. coli. Although optical imaging can provide exquisite details of the spatial organization of biomolecules, there is a mismatch between the scale at which receptor clustering occurs (<300 nm) and the optical diffraction limit (>400 nm). The last decade has seen the emergence of super-resolution imaging methods that effectively break the optical diffraction barrier to yield truly nanoscale information in intact biological samples. This study reports the first visualizations of TLR4 distributions on intact cells at image resolutions of <30 nm using a novel, dual-color stochastic optical reconstruction microscopy (STORM) technique. This methodology permits distinction between receptors containing bound LPS from those without at the nanoscale. Importantly, we also show that LPS derived from immuno-stimulatory bacteria resulted in significantly higher LPS-TLR4 cluster sizes and a nearly two-fold greater ligand/receptor colocalization as compared to immuno-evading LPS. PMID:22807232

Characterization of the First Molluscicidal Lipopolysaccharide from Moraxella osloensis

PubMed Central

Tan, Li; Grewal, Parwinder S.

2003-01-01

Moraxella osloensis is a bacterium that is mutualistically associated with Phasmarhabditis hermaphrodita, a nematode that has potential for the biocontrol of mollusk pests, especially the slug Deroceras reticulatum. We discovered that purified M. osloensis lipopolysaccharide (LPS) possesses a lethal toxicity to D. reticulatum when administered by injection but no contact or oral toxicity to this slug. The toxicity of the LPS resides in the lipid A moiety. M. osloensis LPS was semiquantitated at 6 × 107 endotoxin units per mg. The LPS is a rough-type LPS with an estimated molecular weight of 5,300. Coinjection of galactosamine with the LPS increased the LPS's toxicity to the slug two- to four-fold. The galactosamine-induced sensitization of the slug to the LPS was reversed completely by uridine. PMID:12788774

Characterization of the first molluscicidal lipopolysaccharide from Moraxella osloensis.

PubMed

Tan, Li; Grewal, Parwinder S

2003-06-01

Moraxella osloensis is a bacterium that is mutualistically associated with Phasmarhabditis hermaphrodita, a nematode that has potential for the biocontrol of mollusk pests, especially the slug Deroceras reticulatum. We discovered that purified M. osloensis lipopolysaccharide (LPS) possesses a lethal toxicity to D. reticulatum when administered by injection but no contact or oral toxicity to this slug. The toxicity of the LPS resides in the lipid A moiety. M. osloensis LPS was semiquantitated at 6 x 10(7) endotoxin units per mg. The LPS is a rough-type LPS with an estimated molecular weight of 5,300. Coinjection of galactosamine with the LPS increased the LPS's toxicity to the slug two- to four-fold. The galactosamine-induced sensitization of the slug to the LPS was reversed completely by uridine.

The Sinorhizobium fredii HH103 Lipopolysaccharide Is Not Only Relevant at Early Soybean Nodulation Stages but Also for Symbiosome Stability in Mature Nodules

PubMed Central

Margaret, Isabel; Lucas, M. Mercedes; Acosta-Jurado, Sebastián; Buendía-Clavería, Ana M.; Fedorova, Elena; Hidalgo, Ángeles; Rodríguez-Carvajal, Miguel A.; Rodriguez-Navarro, Dulce N.; Ruiz-Sainz, José E.; Vinardell, José M.

2013-01-01

In this work we have characterised the Sinorhizobium fredii HH103 greA lpsB lpsCDE genetic region and analysed for the first time the symbiotic performance of Sinorhizobium fredii lps mutants on soybean. The organization of the S. fredii HH103 greA, lpsB, and lpsCDE genes was equal to that of Sinorhizobium meliloti 1021. S. fredii HH103 greA, lpsB, and lpsE mutant derivatives produced altered LPS profiles that were characteristic of the gene mutated. In addition, S. fredii HH103 greA mutants showed a reduction in bacterial mobility and an increase of auto-agglutination in liquid cultures. RT-PCR and qPCR experiments demonstrated that the HH103 greA gene has a positive effect on the transcription of lpsB. Soybean plants inoculated with HH103 greA, lpsB or lpsE mutants formed numerous ineffective pseudonodules and showed severe symptoms of nitrogen starvation. However, HH103 greA and lps mutants were also able to induce the formation of a reduced number of soybean nodules of normal external morphology, allowing the possibility of studying the importance of bacterial LPS in later stages of the S. fredii HH103-soybean symbiosis. The infected cells of these nodules showed signs of early termination of symbiosis and lytical clearance of bacteroids. These cells also had very thick walls and accumulation of phenolic-like compounds, pointing to induced defense reactions. Our results show the importance of bacterial LPS in later stages of the S. fredii HH103-soybean symbiosis and their role in preventing host cell defense reactions. S. fredii HH103 lpsB mutants also showed reduced nodulation with Vigna unguiculata, although the symbiotic impairment was less pronounced than in soybean. PMID:24098345

Transcriptional regulation of bone sialoprotein gene by Porphyromonas gingivalis lipopolysaccharide.

PubMed

Li, Xinyue; Kato, Naoko; Mezawa, Masaru; Li, Zhengyang; Wang, Zhitao; Yang, Li; Sasaki, Yoko; Kaneko, Takashi; Takai, Hideki; Yoshimura, Atsutoshi; Ogata, Yorimasa

2010-07-01

Lipopolysaccharide (LPS) is a major mediator of inflammatory response. Periodontopathic bacterium Porphyromonas gingivalis LPS has quite different character from Escherichia coli LPS. E. coli LPS is agonist for Toll-like receptor 4 (TLR4), whereas P. gingivalis LPS worked as antagonist for TLR4. Bone sialoprotein (BSP) is an early marker of osteoblast differentiation. To investigate the effects of P. gingivalis LPS on BSP transcription, we used rat osteoblast-like ROS17/2.8 cells. BSP mRNA levels were decreased by 0.1 microg/ml and increased by 0.01 microg/ml P. gingivalis LPS at 12 h. Results of luciferase assays showed that 0.1 microg/ml decreased and 0.01 microg/ml P. gingivalis LPS increased BSP transcription in -116 to +60 BSP construct. The effects of P. gingivalis LPS were abrogated by double mutations in cAMP response element (CRE) and FGF2 response element (FRE). Tyrosine kinase inhibitor herbimycin A, ERK1/2 inhibitor and antioxidant N-acetylcystein inhibited effects of P. gingivalis LPS. Protein kinase A inhibitor and PI3-kinase/Akt inhibitor only abolished the effect of 0.01 microg/ml P. gingivalis LPS. Furthermore, 0.1 microg/ml LPS decreased the CRE- and FRE-protein complexes formation, whereas 0.01 microg/ml P. gingivalis LPS increased the nuclear protein binding to CRE and FRE. ChIP assays revealed increased binding of CREB1, JunD, Fra2, Runx2, Dlx5, and Smad1 to a chromatin fragment containing the CRE and FRE by 0.01 microg/ml P. gingivalis LPS. These studies therefore indicated that 0.1 microg/ml suppressed, and 0.01 microg/ml P. gingivalis LPS increased BSP gene transcription mediated through CRE and FRE elements in the rat BSP gene promoter. J. Cell. Biochem. 110: 823-833, 2010. (c) 2010 Wiley-Liss, Inc.

EphA2 Receptor Signaling Mediates Inflammatory Responses in Lipopolysaccharide-Induced Lung Injury.

PubMed

Hong, Ji Young; Shin, Mi Hwa; Chung, Kyung Soo; Kim, Eun Young; Jung, Ji Ye; Kang, Young Ae; Kim, Young Sam; Kim, Se Kyu; Chang, Joon; Park, Moo Suk

2015-07-01

Eph receptors and ephrin ligands have several functions including angiogenesis, cell migration, axon guidance, fluid homeostasis, oncogenesis, inflammation and injury repair. The EphA2 receptor potentially mediates the regulation of vascular permeability and inflammation in response to lung injury. Mice were divided into 3 experimental groups to study the role of EphA2 signaling in the lipopolysaccharide (LPS)-induced lung injury model i.e., IgG+phosphate-buffered saline (PBS) group (IgG instillation before PBS exposure), IgG+LPS group (IgG instillation before LPS exposure) and EphA2 monoclonal antibody (mAb)+LPS group (EphA2 mAb pretreatment before LPS exposure). EphA2 and ephrinA1 were upregulated in LPS-induced lung injury. The lung injury score of the EphA2 mAb+LPS group was lower than that of the IgG+LPS group (4.30±2.93 vs. 11.45±1.20, respectively; p=0.004). Cell counts (EphA2 mAb+LPS: 11.33×10(4)±8.84×10(4) vs. IgG+LPS: 208.0×10(4)±122.6×10(4); p=0.018) and total protein concentrations (EphA2 mAb+LPS: 0.52±0.41 mg/mL vs. IgG+LPS: 1.38±1.08 mg/mL; p=0.192) were decreased in EphA2 mAb+LPS group, as compared to the IgG+LPS group. In addition, EphA2 antagonism reduced the expression of phospho-p85, phosphoinositide 3-kinase 110γ, phospho-Akt, nuclear factor κB, and proinflammatory cytokines. This results of the study indicated a role for EphA2-ephrinA1 signaling in the pathogenesis of LPS-induced lung injury. Furthermore, EphA2 antagonism inhibits the phosphoinositide 3-kinase-Akt pathway and attenuates inflammation.

Protective effects of sea buckthorn polysaccharide extracts against LPS/d-GalN-induced acute liver failure in mice via suppressing TLR4-NF-κB signaling.

PubMed

Liu, Huan; Zhang, Wei; Dong, Shichao; Song, Liang; Zhao, Shimin; Wu, Chunyan; Wang, Xue; Liu, Fang; Xie, Jiming; Wang, Jinling; Wang, Yuzhen

2015-12-24

Sea buckthorn (Hippophae rhamnoides L.) berries have been traditionally used to treat gastric disorders, cardiovascular problems, and liver injuries in oriental medicinal system. This study aimed to explore the protective effects and mechanisms of the polysaccharide extracts of Sea buckthorn (HRP) berries against lipopolysaccharide (LPS) and d-galactosamine hydrochloride (d-GalN)-induced acute liver failure in mice. HRP was isolated by hot-water extraction and characterized by HPLC and infrared spectrum analysis. The total carbohydrate, uronic acid and protein contents of HRP were measured by a spectrophotometric method. Mice were orally administrated with HRP (50, 100, 200mg/kg) once daily for 14 consecutive days prior to the challenge with LPS (50 μg/kg) and d-GalN (300 mg/kg). Animals of positive control group were intraperitoneally injected with dexamethasone (10mg/kg). Mice were sacrificed at 8h after LPS/d-GalN injection. Pretreatment with HRP significantly inhibited LPS/d-GalN-induced increases in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, which were accompanied by alleviated liver injuries and reduced production of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). HRP was also found to reduce malondialdehyde (MDA) content and to restore superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) activities. Furthermore, HRP supplementation dose-dependently inhibited the expression of Toll-like receptor 4 (TLR4), phosphorylated extracellular signal-regulated kinase (p-ERK), phosphorylated c-Jun N-terminal kinase (p-JNK), and phosphorylated mitogen activated protein kinase 38 (p-p38 MAPK) in the liver of LPS/d-GalN challenged mice. Pretreatment with HRP also inhibited LPS/d-GalN-induced activation and translocation of nuclear factor-κB (NF-κB). This study indicates that pretreatment with HRP protects against LPS/d-GalN-induced liver injury in mice via suppressing the TLR4-NF-κB signaling pathway. Sea buckthorn may be a hopeful drug for prevention of acute live injury. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Accumulation mode particles and LPS exposure induce TLR-4 dependent and independent inflammatory responses in the lung.

PubMed

Fonceca, Angela M; Zosky, Graeme R; Bozanich, Elizabeth M; Sutanto, Erika N; Kicic, Anthony; McNamara, Paul S; Knight, Darryl A; Sly, Peter D; Turner, Debra J; Stick, Stephen M

2018-01-22

Accumulation mode particles (AMP) are formed from engine combustion and make up the inhalable vapour cloud of ambient particulate matter pollution. Their small size facilitates dispersal and subsequent exposure far from their original source, as well as the ability to penetrate alveolar spaces and capillary walls of the lung when inhaled. A significant immuno-stimulatory component of AMP is lipopolysaccharide (LPS), a product of Gram negative bacteria breakdown. As LPS is implicated in the onset and exacerbation of asthma, the presence or absence of LPS in ambient particulate matter (PM) may explain the onset of asthmatic exacerbations to PM exposure. This study aimed to delineate the effects of LPS and AMP on airway inflammation, and potential contribution to airways disease by measuring airway inflammatory responses induced via activation of the LPS cellular receptor, Toll-like receptor 4 (TLR-4). The effects of nebulized AMP, LPS and AMP administered with LPS on lung function, cellular inflammatory infiltrate and cytokine responses were compared between wildtype mice and mice not expressing TLR-4. The presence of LPS administered with AMP appeared to drive elevated airway resistance and sensitivity via TLR-4. Augmented TLR4 driven eosinophilia and greater TNF-α responses observed in AMP-LPS treated mice independent of TLR-4 expression, suggests activation of allergic responses by TLR4 and non-TLR4 pathways larger than those induced by LPS administered alone. Treatment with AMP induced macrophage recruitment independent of TLR-4 expression. These findings suggest AMP-LPS as a stronger stimulus for allergic inflammation in the airways then LPS alone.

The binding capability of plasma phospholipid transfer protein, but not HDL pool size, is critical to repress LPS induced inflammation.

PubMed

Yu, Yang; Cui, Yingjie; Zhao, Yanan; Liu, Shuai; Song, Guohua; Jiao, Peng; Li, Bin; Luo, Tian; Guo, Shoudong; Zhang, Xiangjian; Wang, Hao; Jiang, Xian-Cheng; Qin, Shucun

2016-02-09

Phospholipid transfer protein (PLTP) participates in high density lipoprotein (HDL) metabolism. Increased plasma PLTP activity was observed in lipopolysaccharide (LPS) triggered acute inflammatory diseases. This study aimed to determine the exact role of PLTP in LPS induced inflammation. HDL pool size was shrunk both in PLTP deficient mice (PLTP-/-) and PLTP transgenic mice (PLTP-Tg). PLTP displayed a strong protective effect on lethal endotoxemia in mice survival study. Furthermore, after LPS stimulation, the expression of pro-inflammatory cytokines were increased in bone marrow derived macrophage (BMDM) from PLTP-/-, while decreased in BMDM from PLTP-Tg compared with BMDM from wild-type mice (WT). Moreover, LPS induced nuclear factor kappa-B (NFκB) activation was enhanced in PLTP-/- BMDM or PLTP knockdown RAW264.7. Conversely, PLTP overexpression countered the NFκB activation in LPS challenged BMDM. Additionally, the activation of toll like receptor 4 (TLR4) induced by LPS showed no alteration in PLTP-/- BMDM. Finally, PLTP could bind to LPS, attenuate the pro-inflammatory effects of LPS, and improve the cell viability in vitro. To sum up, these findings elucidated that PLTP repressed LPS induced inflammation due to extracellular LPS binding capability, and the protective effects were not related to HDL pool size in mice.

Effects of BCG infection on the susceptibility of mouse macrophages to endotoxin.

PubMed Central

Peavy, D L; Baughn, R E; Musher, D M; Musher, D M

1979-01-01

Mice infected intravenously with Mycobacterium bovis (BCG) are 100 to 1,000 times more sensitive to the lethal effects of bacterial lipopolysaccharides (LPS). Since BCG infection results in macrophage activation and LPS may cause pathophysiological effects through interaction with this cell type, it was of interest to determine whether macrophages from BCG-infected animals were more susceptible to the toxic effects of LPS in vitro. When LPS-susceptible, C57BL/6 mice were infected with BCG, a significant reduction in the 50% lethal dose of LPS was first observed after 7 days and persisted for several weeks. Macrophages from these animals had greatly increased susceptibility to LPS in vitro, which correlated with the development of acquired cellular resistance as determined by their ability to inhibit the growth of Listeria monocytogenes. In contrast, BCG infection of C3H/HeJ mice, a strain resistant to LPS, did not alter the 50% lethal dose of LPS for these animals or increase the sensitivity of their peritoneal macrophages to LPS in vitro. These results indicate that susceptibility of BCG-infected mice to the lethal effects of LPS parallels the susceptibility of their macrophages in vitro; release of vasoactive substances from LPS-susceptible activated macrophages in vivo may be, in part, responsible for lethality. PMID:378847

Alkaline Phosphatase Protects Lipopolysaccharide-Induced Early Pregnancy Defects in Mice

PubMed Central

Lei, Wei; Ni, Hua; Herington, Jennifer; Reese, Jeff; Paria, Bibhash C.

2015-01-01

Excessive cytokine inflammatory response due to chronic or superphysiological level of microbial infection during pregnancy leads to pregnancy complications such as early pregnancy defects/loss and preterm birth. Bacterial toxin lipopolysaccharide (LPS), long recognized as a potent proinflammatory mediator, has been identified as a risk factor for pregnancy complications. Alkaline phosphatase (AP) isozymes have been shown to detoxify LPS by dephosphorylation. In this study, we examined the role of alkaline phosphatase (AP) in mitigating LPS-induced early pregnancy complications in mice. We found that 1) the uterus prior to implantation and implantation sites following embryo implantation produce LPS recognition and dephosphorylation molecules TLR4 and tissue non-specific AP (TNAP) isozyme, respectively; 2) uterine TNAP isozyme dephosphorylates LPS at its sites of production; 3) while LPS administration following embryo implantation elicits proinflammatory cytokine mRNA levels at the embryo implantation sites (EISs) and causes early pregnancy loss, dephosphorylated LPS neither triggers proinflammatory cytokine mRNA levels at the EISs nor induces pregnancy complications; 4) AP isozyme supplementation to accelerate LPS detoxification attenuates LPS-induced pregnancy complications following embryo implantation. These findings suggest that a LPS dephosphorylation strategy using AP isozyme may have a unique therapeutic potential to mitigate LPS- or Gram-negative bacteria-induced pregnancy complications in at-risk women. PMID:25910276

Alkaline phosphatase protects lipopolysaccharide-induced early pregnancy defects in mice.

PubMed

Lei, Wei; Ni, Hua; Herington, Jennifer; Reese, Jeff; Paria, Bibhash C

2015-01-01

Excessive cytokine inflammatory response due to chronic or superphysiological level of microbial infection during pregnancy leads to pregnancy complications such as early pregnancy defects/loss and preterm birth. Bacterial toxin lipopolysaccharide (LPS), long recognized as a potent proinflammatory mediator, has been identified as a risk factor for pregnancy complications. Alkaline phosphatase (AP) isozymes have been shown to detoxify LPS by dephosphorylation. In this study, we examined the role of alkaline phosphatase (AP) in mitigating LPS-induced early pregnancy complications in mice. We found that 1) the uterus prior to implantation and implantation sites following embryo implantation produce LPS recognition and dephosphorylation molecules TLR4 and tissue non-specific AP (TNAP) isozyme, respectively; 2) uterine TNAP isozyme dephosphorylates LPS at its sites of production; 3) while LPS administration following embryo implantation elicits proinflammatory cytokine mRNA levels at the embryo implantation sites (EISs) and causes early pregnancy loss, dephosphorylated LPS neither triggers proinflammatory cytokine mRNA levels at the EISs nor induces pregnancy complications; 4) AP isozyme supplementation to accelerate LPS detoxification attenuates LPS-induced pregnancy complications following embryo implantation. These findings suggest that a LPS dephosphorylation strategy using AP isozyme may have a unique therapeutic potential to mitigate LPS- or Gram-negative bacteria-induced pregnancy complications in at-risk women.

Chondroitin Sulfate-Rich Extract of Skate Cartilage Attenuates Lipopolysaccharide-Induced Liver Damage in Mice.

PubMed

Song, Yeong Ok; Kim, Mijeong; Woo, Minji; Baek, Jang-Mi; Kang, Keon-Hee; Kim, Sang-Ho; Roh, Seong-Soo; Park, Chan Hum; Jeong, Kap-Seop; Noh, Jeong-Sook

2017-06-15

The protective effects of a chondroitin sulfate-rich extract (CSE) from skate cartilage against lipopolysaccharide (LPS)-induced hepatic damage were investigated, and its mechanism of action was compared with that of chondroitin sulfate (CS) from shark cartilage. ICR mice were orally administrated 200 mg/kg body weight (BW) of CS or 400 mg/kg BW of CSE for 3 consecutive days, followed by a one-time intraperitoneal injection of LPS (20 mg/kg BW). The experimental groups were vehicle treatment without LPS injection (NC group), vehicle treatment with LPS injection (LPS group), CS pretreatment with LPS injection (CS group), and CSE pretreatment with LPS injection (CSE group). Hepatic antioxidant enzyme expression levels in the CS and CSE groups were increased relative to those in the LPS group. In LPS-insulted hepatic tissue, inflammatory factors were augmented relative to those in the NC group, but were significantly suppressed by pretreatment with CS or CSE. Moreover, CS and CSE alleviated the LPS-induced apoptotic factors and mitogen-activated protein kinase (MAPK). In addition, CS and CSE effectively decreased the serum lipid concentrations and downregulated hepatic sterol regulatory element-binding proteins expression. In conclusion, the skate CSE could protect against LPS-induced hepatic dyslipidemia, oxidative stress, inflammation, and apoptosis, probably through the regulation of MAPK signaling.

Chondroitin Sulfate-Rich Extract of Skate Cartilage Attenuates Lipopolysaccharide-Induced Liver Damage in Mice

PubMed Central

Song, Yeong Ok; Kim, Mijeong; Woo, Minji; Baek, Jang-Mi; Kang, Keon-Hee; Kim, Sang-Ho; Roh, Seong-Soo; Park, Chan Hum; Jeong, Kap-Seop; Noh, Jeong-Sook

2017-01-01

The protective effects of a chondroitin sulfate-rich extract (CSE) from skate cartilage against lipopolysaccharide (LPS)-induced hepatic damage were investigated, and its mechanism of action was compared with that of chondroitin sulfate (CS) from shark cartilage. ICR mice were orally administrated 200 mg/kg body weight (BW) of CS or 400 mg/kg BW of CSE for 3 consecutive days, followed by a one-time intraperitoneal injection of LPS (20 mg/kg BW). The experimental groups were vehicle treatment without LPS injection (NC group), vehicle treatment with LPS injection (LPS group), CS pretreatment with LPS injection (CS group), and CSE pretreatment with LPS injection (CSE group). Hepatic antioxidant enzyme expression levels in the CS and CSE groups were increased relative to those in the LPS group. In LPS-insulted hepatic tissue, inflammatory factors were augmented relative to those in the NC group, but were significantly suppressed by pretreatment with CS or CSE. Moreover, CS and CSE alleviated the LPS-induced apoptotic factors and mitogen-activated protein kinase (MAPK). In addition, CS and CSE effectively decreased the serum lipid concentrations and downregulated hepatic sterol regulatory element-binding proteins expression. In conclusion, the skate CSE could protect against LPS-induced hepatic dyslipidemia, oxidative stress, inflammation, and apoptosis, probably through the regulation of MAPK signaling. PMID:28617322

An effector role for platelets in systemic and local lipopolysaccharide-induced toxicity in mice, mediated by a CD11a- and CD54-dependent interaction with endothelium.

PubMed Central

Piguet, P F; Vesin, C; Ryser, J E; Senaldi, G; Grau, G E; Tacchini-Cottier, F

1993-01-01

The role of platelets was investigated in two models of lipopolysaccharide (LPS)-induced toxicity in mice: the systemic reaction, provoked by intravenous LPS injection in D-galactosamine-sensitized recipients, which results in host death, and the local reaction, elicited in the skin by sequential injections of LPS and tumor necrosis factor alpha at 24-h intervals, which results in hemorrhagic necrosis. In both models, the depletion of platelets with a rabbit polyclonal or a mouse monoclonal antiplatelet immunoglobulin G afforded significant protection. In the local reaction, studies of the distribution of 111In-labelled platelets as well as optical and electron microscopy showed that platelets are localized in the dermal venules before hemorrhage occurs. Anti-CD11a (LFA-1) and anti-CD54 (ICAM-1) monoclonal antibodies prevented both platelet localization and hemorrhagic necrosis, and these determinants were detected on mouse platelets by immunofluorescence. The antiplatelet monoclonal antibody did not reduce the localization of polymorphonuclear leukocytes in the dermal venules, as shown by histological sections. Thus, in the local reaction, the stimulation with LPS and tumor necrosis factor alpha leads to a binding of platelets to the endothelium of venules by their beta 2 integrins, which seems necessary for the development of the hemorrhagic necrosis. Images PMID:8104895

Effect of acupuncture on Lipopolysaccharide-induced anxiety-like behavioral changes: involvement of serotonin system in dorsal Raphe nucleus.

PubMed

Yang, Tae Young; Jang, Eun Young; Ryu, Yeonhee; Lee, Gyu Won; Lee, Eun Byeol; Chang, Suchan; Lee, Jong Han; Koo, Jin Suk; Yang, Chae Ha; Kim, Hee Young

2017-12-11

Acupuncture has been used as a common therapeutic tool in many disorders including anxiety and depression. Serotonin transporter (SERT) plays an important role in the pathology of anxiety and other mood disorders. The aim of this study was to evaluate the effects of acupuncture on lipopolysaccharide (LPS)-induced anxiety-like behaviors and SERT in the dorsal raphe nuclei (DRN). Rats were given acupuncture at ST41 (Jiexi), LI11 (Quchi) or SI3 (Houxi) acupoint in LPS-treated rats. Anxiety-like behaviors of elevated plus maze (EPM) and open field test (OFT) were measured and expressions of SERT and/or c-Fos were also examined in the DRN using immunohistochemistry. The results showed that 1) acupuncture at ST41 acupoint, but neither LI11 nor SI3, significantly attenuated LPS-induced anxiety-like behaviors in EPM and OFT, 2) acupuncture at ST41 decreased SERT expression increased by LPS in the DRN. Our results suggest that acupuncture can ameliorate anxiety-like behaviors, possibly through regulation of SERT in the DRN.

Development of an Immunoassay for Rapid Detection of Ganglioside GM1 Mimicry in Campylobacter jejuni Strains

PubMed Central

Prendergast, Martina M.; Kosunen, Timo U.; Moran, Anthony P.

2001-01-01

Mimicry of peripheral nerve gangliosides by Campylobacter jejuni lipopolysaccharides (LPSs) has been proposed to induce cross-reacting antiganglioside antibodies in Guillain-Barré syndrome (GBS). Because current methods for LPS characterization are labor-intensive and inhibit the screening of large numbers of strains, a rapid GM1 epitope screening assay was developed. Biomass from two agar plates of confluent growth yielded sufficient LPS using a novel phenol-water and ether extraction procedure. Extracts of LPS were reacted with cholera toxin (GM1 ligand), peanut agglutinin (Galβ1→3GalNAc ligand), and anti-GM1 antibodies. After the assay was validated, 12 of 59 (20%) C. jejuni serostrains, including four serotypes that have not previously been associated with GBS, reacted with two or more anti-GM1 ganglioside reagents. Subsequently, LPS extracts from 5 of 7 (71%) C. jejuni isolates and 2 of 3 (67%) C. jejuni culture collection strains bore GM1 structures. Overall, the assay system was reliable, efficient, and reproducible and may be adapted for large-scale epidemiological studies. PMID:11283076

Involvement of cannabinoids in the cardioprotection induced by lipopolysaccharide

PubMed Central

Lagneux, Caroline; Lamontagne, Daniel

2001-01-01

We have examined the involvement of the endocannabinoid system in the cardioprotection triggered by lipopolysaccharide (LPS). Rats were treated with saline or LPS (10 μg Kg−1). 24 h later, hearts were excised, retrogradely perfused, submitted to a low-flow ischaemia (0.6 ml min−1) for 90 min and reperfused for 60 min. Some hearts were perfused with either SR 141716A (a cannabinoid CB1, receptor antagonist 1 μM), SR 144528 (a CB2 receptor anagonist μM), NNLA (3 μM) or sodium nitroprusside (1 μM) 5 min before ischaemia and during the ischaemic period. The cardioprotective effects of LPS treatment, in terms of infarction and functional recovery, were not altered by the perfusion of SR 141716A but abolished by both SR 144528 and NNLA. Finally, SR 144528 abolished the beneficial effects of SNP perfusion. Our results suggest an involvement of endocannabinoids, acting through the CB2 receptors, in the cardioprotection triggered by LPS against myocardial ischaemia. This could be attributed to a relationship between cannabinoids and NO. PMID:11181418

LPS from Escherichia coli protects against indomethacin-induced gastropathy in rats--role of ATP-sensitive potassium channels.

PubMed

Gomes, Antoniella S; Lima, Lívia M F; Santos, Camila L; Cunha, Fernando Q; Ribeiro, Ronaldo A; Souza, Marcellus H L P

2006-10-10

The effect of lipopolysaccharide (LPS) in gastric protection has not been elucidated, but ATP-sensitive potassium (K(ATP)) channels are known to be involved in gastric defense. We evaluated the effect of LPS administration on indomethacin-induced gastropathy, and the role of K(ATP) channels in this event. Rats received intravenous (i.v.) LPS administration. After 1/2, 6, 24 or 48 h, indomethacin was injected. 3H later, gastric damage and myeloperoxidase activity were determined. Another group received LPS and 5 h later, glibenclamide, diazoxide or glibenclamide plus diazoxide. After 1 h, the rats received indomethacin and 3 h later, gastric damage and myeloperoxidase activity were evaluated. LPS reduced dose dependently gastric damage and myeloperoxidase activity induced by indomethacin. Glibenclamide reversed this LPS effect on indomethacin-induced gastropathy. Glibenclamide plus diazoxide administration did not change this LPS effect. Thus LPS has a protective effect against indomethacin-induced gastropathy, probably through activation of K(ATP) channels.

The IRAK-ERK-p67phox-Nox-2 axis mediates TLR4, 2-induced ROS production for IL-1β transcription and processing in monocytes

PubMed Central

Singh, Ankita; Singh, Vishal; Tiwari, Rajiv L.; Chandra, Tulika; Kumar, Ashutosh; Dikshit, Madhu; Barthwal, Manoj K.

2016-01-01

In monocytic cells, Toll-like receptor 4 (TLR4)- and TLR2-induced reactive oxygen species (ROS) cause oxidative stress and inflammatory response; however, the mechanism is not well understood. The present study investigated the role of interleukin-1 receptor-associated kinase (IRAK), extracellular signal-regulated kinase (ERK), p67phox and Nox-2 in TLR4- and TLR2-induced ROS generation during interleukin-1 beta (IL-1β) transcription, processing, and secretion. An IRAK1/4 inhibitor, U0126, PD98059, an NADPH oxidase inhibitor (diphenyleneiodonium (DPI)), and a free radical scavenger (N-acetyl cysteine (NAC))-attenuated TLR4 (lipopolysaccharide (LPS))- and TLR2 (Pam3csk4)-induced ROS generation and IL-1β production in THP-1 and primary human monocytes. An IRAK1/4 inhibitor and siRNA-attenuated LPS- and Pam3csk4-induced ERK-IRAK1 association and ERK phosphorylation and activity. LPS and Pam3csk4 also induced IRAK1/4-, ERK- and ROS-dependent activation of activator protein-1 (AP-1), IL-1β transcription, and IL-1β processing because significant inhibition in AP-1 activity, IL-1β transcription, Pro- and mature IL-β expression, and caspase-1 activity was observed with PD98059, U0126, DPI, NAC, an IRAK1/4 inhibitor, tanshinone IIa, and IRAK1 siRNA treatment. IRAK-dependent ERK-p67phox interaction, p67phox translocation, and p67phox–Nox-2 interaction were observed. Nox-2 siRNA significantly reduced secreted IL-1β, IL-1β transcript, pro- and mature IL-1β expression, and caspase-1 activity indicating a role for Nox-2 in LPS- and Pam3csk4-induced IL-1β production, transcription, and processing. In the present study, we demonstrate that the TLR4- and TLR2-induced IRAK-ERK pathway cross-talks with p67phox-Nox-2 for ROS generation, thus regulating IL-1β transcription and processing in monocytic cells. PMID:26320741

Lipopolysaccharide (LPS) of Porphyromonas gingivalis induces IL-1beta, TNF-alpha and IL-6 production by THP-1 cells in a way different from that of Escherichia coli LPS.

PubMed

Diya Zhang; Lili Chen; Shenglai Li; Zhiyuan Gu; Jie Yan

2008-04-01

Lipopolysaccharide (LPS) derived from the periodontal pathogen Porphyromonas gingivalis has been shown to differ from enterobacterial LPS in structure and function; therefore, the Toll-like receptors (TLRs) and the intracellular inflammatory signaling pathways are accordingly different. To elucidate the signal transduction pathway of P. gingivalis, LPS-induced pro-inflammatory cytokine production in the human monocytic cell line THP-1 was measured by ELISA, and the TLRs were determined by the blocking test using anti-TLRs antibodies. In addition, specific inhibitors as well as Phospho-ELISA kits were used to analyze the intracellular signaling pathways. Escherichia coli LPS was used as the control. In this study, P. gingivalis LPS showed the ability to induce cytokine production in THP-1 cells and its induction was significantly (P < 0.05) suppressed by anti-TLR2 antibody or JNK inhibitor, and the phosphorylation level of JNK was significantly increased (P < 0.05). These results indicate that TLR2-JNK is the main signaling pathway of P. gingivalis LPS-induced cytokine production, while the cytokine induction by E. coli LPS was mainly via TLR4-NF-kappaB and TLR4-p38MAPK. This suggests that P. gingivalis LPS differs from E. coli LPS in its signaling pathway in THP-1 cells, and that the TLR2-JNK pathway might play a significant role in P. gingivalis LPS-induced chronic inflammatory periodontal disease.

Endogenous pleiotrophin and midkine regulate LPS-induced glial responses.

PubMed

Fernández-Calle, Rosalía; Vicente-Rodríguez, Marta; Gramage, Esther; de la Torre-Ortiz, Carlos; Pérez-García, Carmen; Ramos, María P; Herradón, Gonzalo

2018-01-01

Pleiotrophin (PTN) and Midkine (MK) are two growth factors that modulate neuroinflammation. PTN overexpression in the brain prevents LPS-induced astrocytosis in mice but potentiates microglial activation. The modest astrocytic response caused by a low dose of LPS (0.5mg/kg) is blocked in the striatum of MK-/- mice whereas microglial response is unaffected. We have now tested the effects of an intermediate dose of LPS (7.5mg/kg) in glial response in PTN-/- and MK-/- mice. We found that LPS-induced astrocytosis is prevented in prefrontal cortex and striatum of both PTN-/- and MK-/- mice. Some of the morphological changes of microglia induced by LPS tended to increase in both genotypes, particularly in PTN-/- mice. Since we previously showed that PTN potentiates LPS-induced activation of BV2 microglial cells, we tested the activation of FYN kinase, a substrate of the PTN receptor RPTPβ/ζ, and the subsequent ERK1/2 phosphorylation on LPS and PTN-treated BV2 cells. LPS effects on BV2 cells were not affected by the addition of PTN, suggesting that PTN does not recruit the FYN-MAP kinase signaling pathway in order to modulate LPS effects on microglial cells. Taking together, evidences demonstrate that regulation of astroglial responses to LPS administration are highly dependent on the levels of expression of PTN and MK. Further studies are needed to clarify the possible roles of endogenous expression of PTN and MK in LPS-induced microglial responses. Copyright © 2017 Elsevier B.V. All rights reserved.

Zinc supplementation during pregnancy protects against lipopolysaccharide-induced fetal growth restriction and demise through its anti-inflammatory effect.

PubMed

Chen, Yuan-Hua; Zhao, Mei; Chen, Xue; Zhang, Ying; Wang, Hua; Huang, Ying-Ying; Wang, Zhen; Zhang, Zhi-Hui; Zhang, Cheng; Xu, De-Xiang

2012-07-01

LPS is associated with adverse developmental outcomes, including preterm delivery, fetal death, teratogenicity, and intrauterine growth restriction (IUGR). Previous reports showed that zinc protected against LPS-induced teratogenicity. In the current study, we investigated the effects of zinc supplementation during pregnancy on LPS-induced preterm delivery, fetal death and IUGR. All pregnant mice except controls were i.p. injected with LPS (75 μg/kg) daily from gestational day (GD) 15 to GD17. Some pregnant mice were administered zinc sulfate through drinking water (75 mg elemental Zn per liter) throughout the pregnancy. As expected, an i.p. injection with LPS daily from GD15 to GD17 resulted in 36.4% (4/11) of dams delivered before GD18. In dams that completed the pregnancy, 63.2% of fetuses were dead. Moreover, LPS significantly reduced fetal weight and crown-rump length. Of interest, zinc supplementation during pregnancy protected mice from LPS-induced preterm delivery and fetal death. In addition, zinc supplementation significantly alleviated LPS-induced IUGR and skeletal development retardation. Further experiments showed that zinc supplementation significantly attenuated LPS-induced expression of placental inflammatory cytokines and cyclooxygenase-2. Zinc supplementation also significantly attenuated LPS-induced activation of NF-κB and MAPK signaling in mononuclear sinusoidal trophoblast giant cells of the labyrinth zone. It inhibited LPS-induced placental AKT phosphorylation as well. In conclusion, zinc supplementation during pregnancy protects against LPS-induced fetal growth restriction and demise through its anti-inflammatory effect.

Intra-amniotic pharmacological blockade of inflammatory signalling pathways in an ovine chorioamnionitis model.

PubMed

Ireland, D J; Kemp, M W; Miura, Y; Saito, M; Newnham, J P; Keelan, J A

2015-05-01

Intrauterine inflammation (IUI) associated with infection is the major cause of preterm birth (PTB) at <32 weeks' gestation and accounts for ∼40% of all spontaneous PTBs. Pharmacological strategies to prevent PTB and improve fetal outcomes will likely require both antimicrobial and anti-inflammatory therapies. Here we investigated the effects of two cytokine-suppressive anti-inflammatory drugs (CSAIDs), compounds that specifically target inflammatory signalling pathways, in an ovine model of lipopolysaccharide (LPS)-induced chorioamnionitis. Chronically catheterized ewes at 116 days gestation (n = 7/group) received an intra-amniotic (IA) bolus of LPS (10 mg) plus vehicle or CSAIDS: TPCA-1 (1.2 mg/kg fetal weight) or 5z-7-oxozeaenol (OxZnl; 0.4 mg/kg fetal weight); controls received vehicle (dimethylsulphoxide). Amniotic fluid (AF), fetal and maternal blood samples were taken 0, 2, 6, 12, 24 and 48 h later; tissues were taken at autopsy (48 h). Administration of TPCA-1 or OxZnl abrogated the stimulatory effects of LPS (P < 0.01 versus vehicle control) on production of PGE2 in AF, with lesser (non-significant) effects on IL-6 production. Fetal membrane polymorphonuclear cell infiltration score was significantly higher in LPS versus vehicle control animals (P < 0.01), and this difference was absent with TPCA-1 and OxZnl treatment. LPS-induced systemic fetal inflammation was highly variable, with no significant effects of CSAIDs observed. Lung inflammation was evident with LPS exposure, but unaffected by CSAID treatment. We have shown in a large animal model that IA administration of a single dose of CSAIDs can suppress LPS-induced IA inflammatory responses, while fetal effects were minimal. Further development and investigation of these compounds in infectious models is warranted. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Cardiolipins Act as a Selective Barrier to Toll-Like Receptor 4 Activation in the Intestine

PubMed Central

Coats, Stephen R.; Hashim, Ahmed; Paramonov, Nikolay A.; Curtis, Michael A.

2016-01-01

ABSTRACT Intestinal homeostasis mechanisms must protect the host intestinal tissue from endogenous lipopolysaccharides (LPSs) produced by the intestinal microbiota. In this report, we demonstrate that murine intestinal fecal lipids effectively block Toll-like receptor 4 (TLR4) responses to naturally occurring Bacteroidetes sp. LPS. Cardiolipin (CL) represents a significant proportion of the total intestinal and fecal lipids and, furthermore, potently antagonizes TLR4 activation by reducing LPS binding at the lipopolysaccharide binding protein (LBP), CD14, and MD-2 steps of the TLR4 signaling pathway. It is further demonstrated that intestinal lipids and CL are less effective at neutralizing more potent Enterobacteriaceae-type LPS, which is enriched in feces obtained from mice with dextran sodium sulfate (DSS)-treated inflammatory bowel disease. The selective inhibition of naturally occurring LPS structures by intestinal lipids may represent a novel homeostasis mechanism that blocks LPS activation in response to symbiotic but not dysbiotic microbial communities. IMPORTANCE The guts of animals harbor a variety of Gram-negative bacteria associated with both states of intestinal health and states of disease. Environmental factors, such as dietary habits, can drive the microbial composition of the host animal's intestinal bacterial community toward a more pathogenic state. Both beneficial and harmful Gram-negative bacteria are capable of eliciting potentially damaging inflammatory responses from the host intestinal tissues via a lipopolysaccharide (LPS)-dependent pathway. Physical mucosal barriers and antibodies produced by the intestinal immune system protect against the undesired inflammatory effects of LPS, although it is unknown why some bacteria are more effective at overcoming the protective barriers than others. This report describes the discovery of a lipid-type protective barrier in the intestine that reduces the deleterious effects of LPSs from beneficial bacteria but is less effective in dampening the inflammatory effects of LPSs from harmful bacteria, providing a novel mechanistic insight into inflammatory intestinal disorders. PMID:27208127

Synergistic Effects of Psychosocial Stress and Mild Peripheral Infection on Inducing Microglial Activation in the Hippocampal Dentate Gyrus and Long-Lasting Deficits in Hippocampus-Related Memory.

PubMed

Tzeng, Wen-Yu; Su, Chien-Chou; Sun, Li-Han; Cherng, Chianfang G.; Yu, Lung

2018-04-30

Lipopolysaccharide (LPS) treatment and stress may cause immune activation in the brain, an event which has been thought to play a role in mediating stress-induced cognitive dysfunction. However, the enduring impact of psychosocial stress on brain immune activation or cognitive deficits has not been well investigated. Likewise, it remains unexplored whether there exist synergistic effects of psychosocial stress and a weak systemic LPS treatment on brain immune activation and/or cognitive function. In this work, a 10-day social defeat regimen was used to model psychosocial stress and the number and density of ionized calcium-binding adaptor molecule 1 (Iba1)-stained microglia was used to reveal brain immune activation in male Balb/C mice. The social defeat regimen did not cause observable microglial activation in dentate gyrus (DG) 24 h after the conclusion of the regimen. Microglial activation peaked in DG 24 h following a single 1 mg/kg intra-peritoneal LPS injection. At this time point, DG microglial activation was not evident providing 0.125 mg/kg or lower of LPS was used, this dose of LPS was, thus, regarded as the “sub-threshold” in this study. Twenty-four h after the conclusion of the defeat regimen, mice received a social interaction test to determine their defeat stress susceptibility and a “sub-threshold” LPS injection. DG microglial activation was observed in the defeat-stress susceptible, but not in the resilient, mice. Furthermore, the stress-susceptible mice showed impairment in object location and Y maze tasks 24 and 72 h after the “sub-threshold” LPS injection. These results suggest that psychosocial stress, when combined with a negligible peripheral infection, may induce long-lasting hippocampus-related memory deficits exclusively in subjects susceptible to psychosocial stresses.

Prebiotic administration normalizes lipopolysaccharide (LPS)-induced anxiety and cortical 5-HT2A receptor and IL1-β levels in male mice.

PubMed

Savignac, Helene M; Couch, Yvonne; Stratford, Michael; Bannerman, David M; Tzortzis, George; Anthony, Daniel C; Burnet, Philip W J

2016-02-01

The manipulation of the enteric microbiota with specific prebiotics and probiotics, has been shown to reduce the host's inflammatory response, alter brain chemistry, and modulate anxiety behaviour in both rodents and humans. However, the neuro-immune and behavioural effects of prebiotics on sickness behaviour have not been explored. Here, adult male CD1 mice were fed with a specific mix of non-digestible galacto-oligosaccharides (Bimuno®, BGOS) for 3 weeks, before receiving a single injection of lipopolysaccharide (LPS), which induces sickness behaviour and anxiety. Locomotor and marble burying activities were assessed 4h after LPS injection, and after 24h, anxiety in the light-dark box was assessed. Cytokine expression, and key components of the serotonergic (5-Hydroxytryptamine, 5-HT) and glutamatergic system were evaluated in the frontal cortex to determine the impact of BGOS administration at a molecular level. BGOS-fed mice were less anxious in the light-dark box compared to controls 24h after the LPS injection. Elevated cortical IL-1β concentrations in control mice 28 h after LPS were not observed in BGOS-fed animals. This significant BGOS×LPS interaction was also observed for 5HT2A receptors, but not for 5HT1A receptors, 5HT, 5HIAA, NMDA receptor subunits, or other cytokines. The intake of BGOS did not influence LPS-mediated reductions in marble burying behaviour, and its effect on locomotor activity was equivocal. Together, our data show that the prebiotic BGOS has an anxiolytic effect, which may be related to the modulation of cortical IL-1β and 5-HT2A receptor expression. Our data suggest a potential role for prebiotics in the treatment of neuropsychiatric disorders where anxiety and neuroinflammation are prominent clinical features. Copyright © 2015. Published by Elsevier Inc.

Diet-induced obesity reprograms the inflammatory response of the murine lung to inhaled endotoxin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tilton, Susan C., E-mail: susan.tilton@pnnl.gov; Waters, Katrina M.; Karin, Norman J.

The co-occurrence of environmental factors is common in complex human diseases and, as such, understanding the molecular responses involved is essential to determine risk and susceptibility to disease. We have investigated the key biological pathways that define susceptibility for pulmonary infection during obesity in diet-induced obese (DIO) and regular weight (RW) C57BL/6 mice exposed to inhaled lipopolysaccharide (LPS). LPS induced a strong inflammatory response in all mice as indicated by elevated cell counts of macrophages and neutrophils and levels of proinflammatory cytokines (MDC, MIP-1γ, IL-12, RANTES) in the bronchoalveolar lavage fluid. Additionally, DIO mice exhibited 50% greater macrophage cell counts,more » but decreased levels of the cytokines, IL-6, TARC, TNF-α, and VEGF relative to RW mice. Microarray analysis of lung tissue showed over half of the LPS-induced expression in DIO mice consisted of genes unique for obese mice, suggesting that obesity reprograms how the lung responds to subsequent insult. In particular, we found that obese animals exposed to LPS have gene signatures showing increased inflammatory and oxidative stress response and decreased antioxidant capacity compared with RW. Because signaling pathways for these responses can be common to various sources of environmentally induced lung damage, we further identified biomarkers that are indicative of specific toxicant exposure by comparing gene signatures after LPS exposure to those from a parallel study with cigarette smoke. These data show obesity may increase sensitivity to further insult and that co-occurrence of environmental stressors result in complex biosignatures that are not predicted from analysis of individual exposures. - Highlights: ► Obesity modulates inflammatory markers in BAL fluid after LPS exposure. ► Obese animals have a unique transcriptional signature in lung after LPS exposure. ► Obesity elevates inflammatory stress and reduces antioxidant capacity in the lung. ► Toxicant-specific biomarkers predict exposure independent of systemic inflammation.« less

Effect of peroxisome proliferator-activated receptor alpha activators on tumor necrosis factor expression in mice during endotoxemia.

PubMed

Hill, M R; Clarke, S; Rodgers, K; Thornhill, B; Peters, J M; Gonzalez, F J; Gimble, J M

1999-07-01

Inflammatory mediators orchestrate the host immune and metabolic response to acute bacterial infections and mediate the events leading to septic shock. Tumor necrosis factor (TNF) has long been identified as one of the proximal mediators of endotoxin action. Recent studies have implicated peroxisome proliferator-activated receptor alpha (PPARalpha) as a potential target to modulate regulation of the immune response. Since PPARalpha activators, which are hypolipidemic drugs, are being prescribed for a significant population of older patients, it is important to determine the impact of these drugs on the host response to acute inflammation. Therefore, we examined the role of PPARalpha activators on the regulation of TNF expression in a mouse model of endotoxemia. CD-1 mice treated with dietary fenofibrate or Wy-14,643 had fivefold-higher lipopolysaccharide (LPS)-induced TNF plasma levels than LPS-treated control-fed animals. Higher LPS-induced TNF levels in drug-fed animals were reflected physiologically in significantly lower glucose levels in plasma and a significantly lower 50% lethal dose than those in LPS-treated control-fed animals. Utilizing PPARalpha wild-type (WT) and knockout (KO) mice, we showed that the effect of fenofibrate on LPS-induced TNF expression was indeed mediated by PPARalpha. PPARalpha WT mice fed fenofibrate also had a fivefold increase in LPS-induced TNF levels in plasma compared to control-fed animals. However, LPS-induced TNF levels were significantly decreased and glucose levels in plasma were significantly increased in PPARalpha KO mice fed fenofibrate compared to those in control-fed animals. Data from peritoneal macrophage studies indicate that Wy-14,643 modestly decreased TNF expression in vitro. Similarly, overexpression of PPARalpha in 293T cells decreased activity of a human TNF promoter-luciferase construct. The results from these studies suggest that any anti-inflammatory activity of PPARalpha in vivo can be masked by other systemic effects of PPARalpha activators.

Could a B-1 cell derived phagocyte "be one" of the peritoneal macrophages during LPS-driven inflammation?

PubMed

Popi, Ana Flavia; Osugui, Lika; Perez, Katia Regina; Longo-Maugéri, Ieda Maria; Mariano, Mario

2012-01-01

The inflammatory response is driven by signals that recruit and elicit immune cells to areas of tissue damage or infection. The concept of a mononuclear phagocyte system postulates that monocytes circulating in the bloodstream are recruited to inflamed tissues where they give rise to macrophages. A recent publication demonstrated that the large increase in the macrophages observed during infection was the result of the multiplication of these cells rather than the recruitment of blood monocytes. We demonstrated previously that B-1 cells undergo differentiation to acquire a mononuclear phagocyte phenotype in vitro (B-1CDP), and we propose that B-1 cells could be an alternative origin for peritoneal macrophages. A number of recent studies that describe the phagocytic and microbicidal activity of B-1 cells in vitro and in vivo support this hypothesis. Based on these findings, we further investigated the differentiation of B-1 cells into phagocytes in vivo in response to LPS-induced inflammation. Therefore, we investigated the role of B-1 cells in the composition of the peritoneal macrophage population after LPS stimulation using osteopetrotic mice, BALB/Xid mice and the depletion of monocytes/macrophages by clodronate treatment. We show that peritoneal macrophages appear in op/op((-/-)) mice after LPS stimulation and exhibit the same Ig gene rearrangement (VH11) that is often found in B-1 cells. These results strongly suggest that op/op((-/-)) peritoneal "macrophages" are B-1CDP. Similarly, the LPS-induced increase in the macrophage population was observed even following monocyte/macrophage depletion by clodronate. After monocyte/macrophage depletion by clodronate, LPS-elicited macrophages were observed in BALB/Xid mice only following the transfer of B-1 cells. Based on these data, we confirmed that B-1 cell differentiation into phagocytes also occurs in vivo. In conclusion, the results strongly suggest that B-1 cell derived phagocytes are a component of the LPS-elicited peritoneal macrophage population.

LPS-induced knee-joint reactive arthritis and spinal cord glial activation were reduced after intrathecal thalidomide injection in rats.

PubMed

Bressan, Elisângela; Mitkovski, Mišo; Tonussi, Carlos Rogério

2010-10-09

Thalidomide is thought to prevent TNF-α production, and such mechanism could be useful in a spinally delivered drug approach for the control of peripheral inflammation. This study aimed to evaluate the effect of intrathecal thalidomide, in comparison with that of intraperitoneal treatment, on articular incapacitation, edema, synovial leukocyte content, and spinal cord glial activation in a model of Escherichia coli lipopolysaccharide (LPS)-induced reactive arthritis in rats. LPS (30ng) was injected into a knee-joint previously primed with carrageenan (300μg). Systemic (30 and 100mg/kg; intraperitoneal, i.p.) and intrathecal (10 and 100μg; i.t.) thalidomide were given 1h or 20min before LPS injection, respectively. Articular incapacitation and edema were evaluated hourly. After 6h, synovial fluid and lumbar spinal cords were collected for subsequent evaluations of cell migration and expression of CD11b/c and GFAP markers, respectively. Systemic (30 and 100mg/kg) or intrathecal (10 and 100μg) thalidomide reduced articular incapacitation, edema, and polymorphonuclear migration. In addition, i.p. and i.t. thalidomide reduced the expression of CD11b/c and GFAP markers in the lumbar spinal cord. These results suggest that thalidomide can also produce peripheral anti-inflammatory effects through action in the spinal cord that may involve glia inhibition. This study provides new evidence that the direct spinal delivery of immunomodulators may be an alternative for the treatment of arthritic diseases, which require long systemic treatment with drugs associated with undesirable side effects. Copyright © 2010 Elsevier Inc. All rights reserved.

Naringenin ameliorates learning and memory impairment following systemic lipopolysaccharide challenge in the rat.

PubMed

Khajevand-Khazaei, Mohammad-Reza; Ziaee, Pouria; Motevalizadeh, Seyyed-Alireza; Rohani, Mahdi; Afshin-Majd, Siamak; Baluchnejadmojarad, Tourandokht; Roghani, Mehrdad

2018-05-05

Systemic inflammation following infection is usually associated with long-term complications including cognitive deficit and dementia. Neuroinflammation and cognitive decline are also main hallmarks of several neurological conditions. Naringenin is a citrus flavanone with anti-inflammatory, neuroprotective, and antioxidant potential. In this study, the protective effect of naringenin against lipopolysaccharide (LPS)-induced cognitive decline was evaluated in the rat. LPS was daily injected at a dose of 167 μg/kg for 1 week and naringenin was administered p.o. at doses of 25, 50, or 100 mg/kg/day. Treatment of LPS-injected rats with naringenin dose-dependently improved spatial recognition memory in Y maze, discrimination ratio in novel object discrimination task, and retention and recall capability in passive avoidance test. Furthermore, naringenin lowered hippocampal malondialdehyde (MDA) as an index of lipid peroxidation and improved antioxidant defensive system comprising superoxide dismutase (SOD), catalase, and glutathione (GSH) in addition to decreasing acetylcholinesterase (AChE) activity. Additionally, naringenin was able to lower hippocampal nuclear factor-kappaB (NF-κB), toll-like receptor 4 (TLR4), tumor necrosis factor α (TNFα), cyclooxygenase-2 (COX2), inducible nitric oxide synthase (iNOS), glial fibrillary acidic protein (GFAP) level and its immunoreactivity, and to elevate nuclear factor (erythroid-derived 2)-like 2 (Nrf2). Taken together, naringenin could alleviate LPS-induced cognitive deficits and neuroinflammation, as was evident from attenuation of oxidative stress and AChE and modulation of Nrf2/NF-κB/TNFα/COX2/iNOS/TLR4/GFAP. Copyright © 2018 Elsevier B.V. All rights reserved.

Protection of BALB/C mice against Brucella abortus 544 challenge by vaccination with combination of recombinant human serum albumin-l7/l12 (Brucella abortus ribosomal protein) and lipopolysaccharide.

PubMed

Pakzad, Iraj; Rezaee, Abbas; Rasaee, Mohammad J; Hossieni, Ahmad Zavaran; Tabbaraee, Bahman; Kazemnejad, Anoshirvan

2010-01-01

The immunogenic Brucella abortus ribosomal protein L7/L12 and Lipopolysaccharide (LPS) are promising candidate antigens for the development of subunit vaccines against brucellosis. This study was aimed to evaluate the protection of combination of recombinant HSA-L7/L12 fusion protein with LPS in Balb/c mouse. The recombinant HSA-L7/L12 fusion protein in Saccharomyces cerevisiae was expressed and purified by affinity chromatography column. LPS was extracted by n-butanol, purified by ultracentrifugation. BALB/c mouses were immunized in 9 groups with PBS, HSA, tHSA-L7/L12, L7/L12, LPS, LPS+ HSA, LPS+ tHSA-L7/L12, LPS+ L7/L12, B. abortus S19. ELISA, LTT tests and challenging two weeks after last injection were carried out. Bacterial count of spleen of immunized BALB/c mouse was done four weeks after challenging with virulent strain B. abortus 544. In ELISA test the specific antibodies of tHSA-L7/L12 exhibited a dominance of immunoglobulin IgG1 over IgG2a. LPS-HSA and tHSA-L7/L12 + LPS produced a significantly higher antibody titer than LPS alone and L7/L12+LPS (P < 0.05). The predominant IgG subtype for LPS and L7/L12+LPS were IgG3. However, tHSA-L7/L12+ LPS and LPS+ HAS elicited predominantly IgG1 and IgG3 subtypes. In addition, the tHSA-L7/L12 fusion protein and L7/L12 elicited a strong T-cell proliferative response upon restimulation in vitro with recombinant tHSA-L7/L12 and L7/L12, suggesting the induction of a cellular immunity response in vivo. However, there was no significant difference proliferative response in L7/L12 and tHSA-L7/L12 fusion protein (P > 0.05). The combination of tHSA-L7/L12 fusion protein with LPS and B. abortus S19 induce higher level of protection against challenge with the virulent strain B. abortus 544 in BALB/c mice than other groups (P = 0.005). The combination of tHSA-L7/L12 fusion protein with LPS had higher protective ability than LPS and fusion protein distinctly.

Cathepsin S Is Involved in Th17 Differentiation Through the Upregulation of IL-6 by Activating PAR-2 after Systemic Exposure to Lipopolysaccharide from Porphyromonas gingivalis.

PubMed

Dekita, Masato; Wu, Zhou; Ni, Junjun; Zhang, Xinwen; Liu, Yicong; Yan, Xu; Nakanishi, Hiroshi; Takahashi, Ichiro

2017-01-01

Positive links have been found between periodontitis and numerous diseases in humans via persistent inflammation throughout the body. However, the main factors responsible for maintaining this pro-inflammatory condition are poorly understood. The spleen, the largest secondary immune organ, is a central hub regulating the immune response/inflammation due to the dendritic cell (DC) response to CD4 + T cell subtype differentiation, and lysosomal proteinase cathepsin S (CatS) is known to be involved in DC functions. In the present study, we found that CatS-induced IL-6 production by splenic DCs subsequently promotes Th17 differentiation, in response to systemic exposure to lipopolysaccharide derived from Porphyromonas gingivalis (PgLPS). The population of CD11c + DCs was significantly increased in the splenic marginal zone (MZ) locally of wild-type (DBA/2) mice with splenomegaly but not in that of CatS deficient ( CatS -/- ) mice after systemic exposure to PgLPS for 7 consecutive days (5 mg/kg/day, intraperitoneal). Similarly, the population of Th17 + CD4 + T cells was also significantly increased in the splenic MZ of wild-type mice but not in that of CatS -/- mice after PgLPS exposure. Furthermore, the increase in the Th17 + CD4 + T cell population paralleled increases in the levels of CatS and IL-6 in CD11c + cells in the splenic MZ. In isolated primary splenic CD11c + cells, the mRNA expression and the production of IL-6 was dramatically increased in wild-type mice but not in CatS - /- mice after direct stimulation with PgLPS (1 μg/ml), and this PgLPS-induced increase in the IL-6 expression was completely abolished by pre-treatment with Z-Phe-Leu-COCHO (Z-FL), the specific inhibitor of CatS. The PgLPS activated protease-activated receptor (PAR) 2 in the isolated splenic CD11c + cells was also significantly inhibited by CatS deficiently. In addition, the PgLPS - induced increase in the IL-6 production by splenic CD11c + cells was completely abolished by pre-treatment with FSLLRY-NH 2 , a PAR2 antagonist, as well as Akti, a specific inhibitor of Akt. These findings indicate that CatS plays a critical role in driving splenic DC-dependent Th17 differentiation through the upregulation of IL-6 by activating PAR2 after exposure to components of periodontal bacteria. Therefore, CatS-specific inhibitors may be effective in alleviating periodontitis-related immune/inflammation.

Histological changes and some in vitro biological activities induced by lipopolysaccharide from Bacteroides gingivalis.

PubMed

Isogai, H; Isogai, E; Fujii, N; Oguma, K; Kagota, W; Takano, K

1988-07-01

The biological activities of lipopolysaccharide from Bacteroides gingivalis 381 (B-LPS) were examined in vivo and in vitro. Intra-oral mucosal injection of B-LPS induced an acute inflammation at the injection site. Intravenous injection of B-LPS induced necrotic lesions with many thrombi in the liver and lymphocytic reduction in the spleen. By immunohistochemical examination, B-LPS was detected in macrophages in the liver, spleen and lymph nodes. In vitro analysis showed that B-LPS was a potent activator of both neutrophils and macrophages in luminol-dependent response and IL-1 secretion from macrophages and was mitogenic to the spleen cells not only from BALB/c mice but also from LPS-non-responder C3H/HeJ mice. Interferon production from human peripheral mononuclear leucocytes was induced, in vitro, by stimulation with B-LPS but not with the other enterobacterial LPS. These findings clarified the various biological activities of B-LPS affecting various cells and tissues, especially neutrophils, macrophages and lymphocytes. The potent inflammability of B-LPS shown in the present study indicates that it is one of the effective agents to induce periodontitis.

Role of T Cells and Gamma Interferon during Induction of Hypersensitivity to Lipopolysaccharide by Toxic Shock Syndrome Toxin 1 in Mice

PubMed Central

Dinges, Martin M.; Schlievert, Patrick M.

2001-01-01

The superantigenic function of toxic shock syndrome toxin 1 (TSST-1) is generally regarded as an important determinant of its lethal effects in humans or experimental animals. This study examined the role of superantigenicity in a BALB/c mouse model of lethal TSST-1-induced hypersensitivity to lipopolysaccharide (LPS). In this model, TSST-1 greatly potentiated both LPS-induced lethality, as well as LPS-induced serum tumor necrosis factor alpha (TNF-α) activity. Although BALB/c-SCID mice were resistant to these LPS enhancement effects of TSST-1, BALB/c-SCID mice reconstituted with T cells were completely susceptible to the enhancement effect of TSST-1 on LPS-induced serum TNF-α. Mice pretreated with cyclosporine (Cs) or neutralizing antibodies against gamma interferon (IFN-γ) did not develop lethal LPS hypersensitivity when injected with TSST-1, and these agents reduced the enhancement effect of TSST-1 on LPS-induced serum TNF-α by 99 and 85%, respectively. Cs pretreatment also completely inhibited the known capacity of TSST-1 to amplify LPS-induced levels of IFN-γ in serum. In contrast, mice given Cs after a priming injection of TSST-1, but before LPS, still exhibited lethal hypersensitivity to LPS. Cs given after TSST-1 also did not inhibit enhancement of LPS-induced serum TNF-α by TSST-1 but inhibited the enhancement effect of TSST-1 on LPS-induced serum IFN-γ by 50%. These experiments support the theory that TSST-1-induced hypersensitivity to LPS is mediated primarily by IFN-γ derived from superantigen-activated T cells. PMID:11179286

Effects of intermittent fasting on age-related changes on Na,K-ATPase activity and oxidative status induced by lipopolysaccharide in rat hippocampus.

PubMed

Vasconcelos, Andrea Rodrigues; Kinoshita, Paula Fernanda; Yshii, Lidia Mitiko; Marques Orellana, Ana Maria; Böhmer, Ana Elisa; de Sá Lima, Larissa; Alves, Rosana; Andreotti, Diana Zukas; Marcourakis, Tania; Scavone, Cristoforo; Kawamoto, Elisa Mitiko

2015-05-01

Chronic neuroinflammation is a common characteristic of neurodegenerative diseases, and lipopolysaccharide (LPS) signaling is linked to glutamate-nitric oxide-Na,K-ATPase isoforms pathway in central nervous system (CNS) and also causes neuroinflammation. Intermittent fasting (IF) induces adaptive responses in the brain that can suppress inflammation, but the age-related effect of IF on LPS modulatory influence on nitric oxide-Na,K-ATPase isoforms is unknown. This work compared the effects of LPS on the activity of α1,α2,3 Na,K-ATPase, nitric oxide synthase gene expression and/or activity, cyclic guanosine monophosphate, 3-nitrotyrosine-containing proteins, and levels of thiobarbituric acid-reactive substances in CNS of young and older rats submitted to the IF protocol for 30 days. LPS induced an age-related effect in neuronal nitric oxide synthase activity, cyclic guanosine monophosphate, and levels of thiobarbituric acid-reactive substances in rat hippocampus that was linked to changes in α2,3-Na,K-ATPase activity, 3-nitrotyrosine proteins, and inducible nitric oxide synthase gene expression. IF induced adaptative cellular stress-response signaling pathways reverting LPS effects in rat hippocampus of young and older rats. The results suggest that IF in both ages would reduce the risk for deficits on brain function and neurodegenerative disorders linked to inflammatory response in the CNS. Copyright © 2015 Elsevier Inc. All rights reserved.

Bacterial DNA indicated as an important inducer of fish cathelicidins.

PubMed

Maier, Valerie Helene; Schmitt, Clemens Nikolaus Zeno; Gudmundsdottir, Sigridur; Gudmundsson, Gudmundur Hrafn

2008-04-01

Cathelicidins are antimicrobial peptides indicated as important in the control of the natural microflora as well as in the fight against bacterial invasion in mammals. Little is known about cathelicidins in fish and here the Chinook salmon (Oncorhynchus tshawytscha) embryo cell line (CHSE-214) was used as a model system to study the expression of cathelicidins due to fish pathogenic bacteria. The cDNA of cathelicidin from CHSE-214 cells (csCath) was cloned and shown to be closely related to gene 2 of both rainbow trout and Atlantic salmon. The deducted amino acid sequence showed highest sequence identity to rtCath2 with 95% and 72% for the cathelin and the antibacterial part, respectively. Cathelicidin gene expression was studied and various Gram positive and Gram negative bacteria caused the upregulation of the gene (csCath). Bacterial DNA and protein were shown important for the induction of cathelicidin expression in these cells. LPS (Escherichia coli) also causes the upregulation of cathelicidins, but digestion of the LPS with DNase I before incubation of the cells, totally abolished the upregulation of cathelicidin and suggests DNA contamination in the LPS to be the trigger for this effect. These results could explain the limited responsiveness of fish cells towards pure LPS and confirm previous suggestions that fish cells are less sensitive to LPS than mammalian cells.