IL4R alpha mutations are associated with asthma exacerbations and mast cell/IgE expression.

PubMed

Wenzel, Sally E; Balzar, Silvana; Ampleford, Elizabeth; Hawkins, Gregory A; Busse, William W; Calhoun, William J; Castro, Mario; Chung, K Fan; Erzurum, Serpil; Gaston, Benjamin; Israel, Elliot; Teague, W Gerald; Curran-Everett, Douglas; Meyers, Deborah A; Bleecker, Eugene R

2007-03-15

Severe asthma has been associated with severe exacerbations, lower lung function and greater tissue inflammation. Previous studies have suggested that mutations in interleukin-4 receptor alpha (IL4Ralpha) are associated with lower lung function, higher IgE, and a gain in receptor function. However, an effect on exacerbations and tissue inflammation has not been shown. Allelic substitutions in IL4Ralpha are associated with asthma exacerbations, lower lung function, and tissue inflammation, in particular to mast cells and IgE. Two well-characterized cohorts of subjects with severe asthma were analyzed for five single nucleotide polymorphisms (SNPs) in IL4Ralpha. These polymorphisms were compared with the history of severe asthma exacerbations and lung function. In the primary (National Jewish) cohort, these polymorphisms were also compared with endobronchial tissue inflammatory cells and local IgE. In both cohorts, the presence of the minor alleles at E375A and Q551R, which were more common in African Americans, was associated with a history of severe exacerbations and lower lung function. In the National Jewish cohort, the C allele at E375A was associated with higher tissue mast cells and higher levels of IgE bound to mast cells. The significance for most of these associations remained when whites (the larger racial subgroup) were analyzed separately. SNPs in IL4Ralpha, which are more common in African Americans, are associated with severe asthma exacerbations, lower lung function, and increased mast cell-related tissue inflammation. Further studies of the impact of these mutations in African Americans and on receptor function are indicated.

Genomic profiling of tumor necrosis factor alpha (TNF-alpha) receptor and interleukin-1 receptor knockout mice reveals a link between TNF-alpha signaling and increased severity of 1918 pandemic influenza virus infection

USDA-ARS?s Scientific Manuscript database

The influenza pandemic of 1918-1919 was one of the worst global pandemics in recent history. The highly pathogenic nature of the 1918 virus is thought to be mediated in part by a dysregulation of the host response, including an exacerbated pro-inflammatory cytokine response. In the present study, we...

Activation of protein kinase C and disruption of endothelial monolayer integrity by sodium arsenite-Potential mechanism in the development of atherosclerosis

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

Pereira, Flavia E.; Coffin, J. Douglas; Beall, Howard D.

2007-04-15

Arsenic exposure has been shown to exacerbate atherosclerosis, beginning with activation of the endothelium that lines the vessel wall. Endothelial barrier integrity is maintained by proteins of the adherens junction (AJ) such as vascular endothelial cadherin (VE-cadherin) and {beta}-catenin and their association with the actin cytoskeleton. In the present study, human aortic endothelial cells (HAECs) were exposed to 1, 5 and 10 {mu}M sodium arsenite [As(III)] for 1, 6, 12 and 24 h, and the effects on endothelial barrier integrity were determined. Immunofluorescence studies revealed formation of actin stress fibers and non-uniform VE-cadherin and {beta}-catenin staining at cell-cell junctions thatmore » were concentration- and time-dependent. Intercellular gaps were observed with a measured increase in endothelial permeability. In addition, concentration-dependent increases in tyrosine phosphorylation (PY) of {beta}-catenin and activation of protein kinase C{alpha} (PKC{alpha}) were observed. Inhibition of PKC{alpha} restored VE-cadherin and {beta}-catenin staining at cell-cell junctions and abolished the As(III)-induced formation of actin stress fibers and intercellular gaps. Endothelial permeability and PY of {beta}-catenin were also reduced to basal levels. These results demonstrate that As(III) induces activation of PKC{alpha}, which leads to increased PY of {beta}-catenin downstream of PKC{alpha} activation. Phosphorylation of {beta}-catenin plausibly severs the association of VE-cadherin and {beta}-catenin, which along with formation of actin stress fibers, results in intercellular gap formation and increased endothelial permeability. To the best of our knowledge, this is the first report demonstrating that As(III) causes a loss of endothelial monolayer integrity, which potentially could contribute to the development of atherosclerosis.« less

Rapid detection of α-thalassaemia variants using droplet digital PCR.

PubMed

Lee, T-Y; Lai, M-I; Ramachandran, V; Tan, J A M A; Teh, L-K; Othman, R; Hussein, N H; George, E

2016-08-01

Alpha thalassaemia is a highly prevalent disease globally and is a well-known public health problem in Malaysia. The deletional forms of the mutation are the most common forms found in alpha thalassaemia. The three most common deletional alpha thalassaemia found in this region include --(SEA) deletion, -α(3.7) rightward and -α(4.2) leftward deletions. The prevalence rate of triplication alpha cases such as ααα(anti3.7) and ααα(anti4.2) is not known in Malaysia although it plays a role in exacerbating the clinical phenotypes in beta thalassaemia carriers. Recently, there have been more reported cases of rare alpha thalassaemia mutations due to the advancement of molecular techniques involved in thalassaemia detections. Therefore, it is essential to develop a new method which allows the detection of different alpha thalassaemia mutations including the rare ones simultaneously and accurately. The purpose of this study was to design an assay for the detection of triplications, common and rare deletional alpha thalassaemia using droplet digital PCR (ddPCR). This is a quantitative detection method to measure the changes of copy number which can detect deletions, duplications and triplications of the alpha globin gene simultaneously. In conclusion, ddPCR is an alternative method for rapid detection of alpha thalassaemia variants in Malaysia. © 2016 John Wiley & Sons Ltd.

Daily activity during stability and exacerbation of chronic obstructive pulmonary disease.

PubMed

Alahmari, Ayedh D; Patel, Anant R C; Kowlessar, Beverly S; Mackay, Alex J; Singh, Richa; Wedzicha, Jadwiga A; Donaldson, Gavin C

2014-06-02

During most COPD exacerbations, patients continue to live in the community but there is little information on changes in activity during exacerbations due to the difficulties of obtaining recent, prospective baseline data. Patients recorded on daily diary cards any worsening in respiratory symptoms, peak expiratory flow (PEF) and the number of steps taken per day measured with a Yamax Digi-walker pedometer. Exacerbations were defined by increased respiratory symptoms and the number of exacerbations experienced in the 12 months preceding the recording of daily step count used to divide patients into frequent (> = 2/year) or infrequent exacerbators. The 73 COPD patients (88% male) had a mean (±SD) age 71(±8) years and FEV1 53(±16)% predicted. They recorded pedometer data on a median 198 days (IQR 134-353). At exacerbation onset, symptom count rose by 1.9(±1.3) and PEF fell by 7(±13) l/min. Mean daily step count fell from 4154(±2586) steps/day during a preceding baseline week to 3673(±2258) step/day during the initial 7 days of exacerbation (p = 0.045). Patients with larger falls in activity at exacerbation took longer to recover to stable level (rho = -0.56; p < 0.001). Recovery in daily step count was faster (median 3.5 days) than for exacerbation symptoms (median 11 days; p < 0.001). Recovery in step count was also faster in untreated compared to treated exacerbation (p = 0.030).Daily step count fell faster over time in the 40 frequent exacerbators, by 708 steps/year, compared to 338 steps/year in 33 infrequent exacerbators (p = 0.002). COPD exacerbations reduced physical activity and frequent exacerbations accelerate decline in activity over time.

Increased alpha 2-macroglobulin in diabetes: a hyperglycemia related phenomenon associated with reduced antithrombin III activity.

PubMed

Ceriello, A; Giugliano, D; Quatraro, A; Stante, A; Dello Russo, P; Torella, R

1989-01-01

Increased alpha 2-macroglobulin (alpha 2M) activity and concentration, and decreased antithrombin III (ATIII) plasma concentration are reported in diabetic subjects. In diabetes an inverse correlation between ATIII activity and blood glucose, HbA1, alpha 2M activity and alpha 2M concentration, and a direct correlation between both alpha 2M activity and alpha 2M concentration with blood glucose and HbA1 are found. Moreover, a direct correlation between alpha 2M activity and alpha 2M concentration fails. In both diabetic and normal subjects induced hyperglycemia increases alpha 2M activity and alpha 2M concentration reduces ATIII activity, while ATIII concentration is not affected. These data which show that hyperglycemia may increase alpha 2M molecule levels while altering only the biological function of ATIII, provide evidence that hyperglycemia may decrease, directly, the biological function of some proteins and may condition the levels of some risk factors for the development of diabetic complications such as alpha 2M.

Blood Coagulation and Asthma Exacerbation in Children.

PubMed

Manuyakorn, Wiparat; Mairiang, Dara; Sirachainan, Nongnuch; Kadegasem, Praguywan; Kamchaisatian, Wasu; Benjaponpitak, Suwat; Chuansumrit, Ampaiwan

2016-01-01

Recent studies have demonstrated the activation of coagulation pathways in asthmatic airways. This study aimed to determine systemic blood coagulation during asthma exacerbation compared with the stable state in children. Pediatric patients (aged between 5 and 15 years) suffering from asthma exacerbation were enrolled. von Willebrand factor (vWF), plasminogen activator inhibitor type-1 (PAI-1), protein C, D-dimer, prothrombin fragment 1 + 2 (F1 + 2), thrombin-antithrombin complex (TAT), and C-reactive protein (CRP) levels were measured during asthma exacerbation and stable state. A total of 22 patients were enrolled. The median vWF, PAI-1, and CRP during asthma exacerbation were significantly higher than those of the stable state: 147.5% (interquartile range, IQR: 111.05-196.57) versus 94% (IQR: 69.72-109.62, p < 0.001), 41.9 ng/ml (IQR: 21.91-48.61) versus 26.17 ng/ml (IQR: 15.89-34.44, p < 0.03), and 4.46 mg/l (IQR: 2.15-16.23) versus 0.87 mg/l (IQR: 0.20-3.89, p < 0.015), respectively. However, the median protein C during asthma exacerbation was significantly lower than that of the stable state: 99.5% (IQR: 86.75-117) versus 113% (IQR: 94-115.25), p = 0.01. No significant difference was found between the levels of D-dimer, F1 + 2, and TAT during asthma exacerbation and stable state. Ultimately, D-dimer was positively correlated with asthma exacerbation score (R = 0.466, p = 0.027). A significant correlation was observed between vWF and CRP (R = 0.527, p = 0.012). Evidence was found of increased endothelial activation and increased PAI-1 during asthma exacerbation. This may emphasize the potential role of blood coagulation in asthma exacerbation. © 2016 S. Karger AG, Basel.

Daily activity during stability and exacerbation of chronic obstructive pulmonary disease

PubMed Central

2014-01-01

Background During most COPD exacerbations, patients continue to live in the community but there is little information on changes in activity during exacerbations due to the difficulties of obtaining recent, prospective baseline data. Methods Patients recorded on daily diary cards any worsening in respiratory symptoms, peak expiratory flow (PEF) and the number of steps taken per day measured with a Yamax Digi-walker pedometer. Exacerbations were defined by increased respiratory symptoms and the number of exacerbations experienced in the 12 months preceding the recording of daily step count used to divide patients into frequent (> = 2/year) or infrequent exacerbators. Results The 73 COPD patients (88% male) had a mean (±SD) age 71(±8) years and FEV1 53(±16)% predicted. They recorded pedometer data on a median 198 days (IQR 134–353). At exacerbation onset, symptom count rose by 1.9(±1.3) and PEF fell by 7(±13) l/min. Mean daily step count fell from 4154(±2586) steps/day during a preceding baseline week to 3673(±2258) step/day during the initial 7 days of exacerbation (p = 0.045). Patients with larger falls in activity at exacerbation took longer to recover to stable level (rho = −0.56; p < 0.001). Recovery in daily step count was faster (median 3.5 days) than for exacerbation symptoms (median 11 days; p < 0.001). Recovery in step count was also faster in untreated compared to treated exacerbation (p = 0.030). Daily step count fell faster over time in the 40 frequent exacerbators, by 708 steps/year, compared to 338 steps/year in 33 infrequent exacerbators (p = 0.002). Conclusions COPD exacerbations reduced physical activity and frequent exacerbations accelerate decline in activity over time. PMID:24885188

Partial agonist clonidine mediates alpha(2)-AR subtypes specific regulation of cAMP accumulation in adenylyl cyclase II transfected DDT1-MF2 cells.

PubMed

Limon-Boulez, I; Bouet-Alard, R; Gettys, T W; Lanier, S M; Maltier, J P; Legrand, C

2001-02-01

alpha2-Adrenergic receptor (alpha(2)-AR) activation in the pregnant rat myometrium at midterm potentiates beta(2)-AR stimulation of adenylyl cyclase (AC) via Gbetagamma regulation of the type II isoform of adenylyl cyclase. However, at term, alpha(2)-AR activation inhibits beta(2)-AR stimulation of AC. This phenomenon is associated with changes in alpha(2)-AR subtype expression (midterm alpha(2A/D)-AR > alpha(2B)-AR; term alpha(2B) >or =alpha(2A/D)-AR), without any change in ACII mRNA, suggesting that alpha(2A/D)- and alpha(2B)-AR differentially regulate beta(2)-cAMP production. To address this issue, we have stably expressed the same density of alpha(2A/D)- or alpha(2B)-AR with AC II in DDT1-MF2 cells. Clonidine (partial agonist) increased beta(2)-AR-stimulated cAMP production in alpha(2A/D)-AR-ACII transfectants but inhibited it in alpha(2B)-AR-ACII transfectants. In contrast, epinephrine (full agonist) enhanced beta(2)-stimulated ACII in both alpha(2A)- and alpha(2B)-ACII clonal cell lines. 4-Azidoanilido-[alpha-(32)P]GTP-labeling of activated G proteins indicated that, in alpha(2B)-AR transfectants, clonidine activated only Gi(2), whereas epinephrine, the full agonist, effectively coupled to Gi(2) and Gi(3). Thus, partial and full agonists selectively activate G proteins that lead to drug specific effects on effectors. Moreover, these data indicate that Gi(3) activation is required for potentiation of beta(2)-AR stimulation of AC by alpha(2A/D) and alpha(2B)-AR in DDT1-MF2 cells. This may reflect an issue of the amount of Gbetagamma released upon receptor activation and/or betagamma composition of Gi(3) versus Gi(2).

Assessment of Aerobic Exercise Adverse Effects during COPD Exacerbation Hospitalization

PubMed Central

Mesquita, Carolina Bonfanti; Caram, Laura M. O.; Dourado, Victor Zuniga; de Godoy, Irma; Tanni, Suzana Erico

2017-01-01

Introduction. Aerobic exercise performed after hospital discharge for exacerbated COPD patients is already recommended to improve respiratory and skeletal muscle strength, increase tolerance to activity, and reduce the sensation of dyspnea. Previous studies have shown that anaerobic activity can clinically benefit patients hospitalized with exacerbated COPD. However, there is little information on the feasibility and safety of aerobic physical activity performed by patients with exacerbated COPD during hospitalization. Objective. To evaluate the effects of aerobic exercise on vital signs in hospitalized patients with exacerbated COPD. Patients and Methods. Eleven COPD patients (63% female, FEV1: 34.2 ± 13.9% and age: 65 ± 11 years) agreed to participate. Aerobic exercise was initiated 72 hours after admission on a treadmill; speed was obtained from the distance covered in a 6-minute walk test (6MWT). Vital signs were assessed before and after exercise. Results. During the activity systolic blood pressure increased from 125.2 ± 13.6 to 135.8 ± 15.0 mmHg (p = 0.004) and respiratory rate from 20.9 ± 4.4 to 24.2 ± 4.5 rpm (p = 0.008) and pulse oximetry (SpO2) decreased from 93.8 ± 2.3 to 88.5 ± 5.7% (p < 0.001). Aerobic activity was considered intense, heart rate ranged from 99.2 ± 11.5 to 119.1 ± 11.1 bpm at the end of exercise (p = 0.092), and patients reached on average 76% of maximum heart rate. Conclusion. Aerobic exercise conducted after 72 hours of hospitalization in patients with exacerbated COPD appears to be safe. PMID:28265180

NOD2: a potential target for regulating liver injury.

PubMed

Body-Malapel, Mathilde; Dharancy, Sébastien; Berrebi, Dominique; Louvet, Alexandre; Hugot, Jean-Pierre; Philpott, Dana J; Giovannini, Marco; Chareyre, Fabrice; Pages, Gilles; Gantier, Emilie; Girardin, Stephen E; Garcia, Irène; Hudault, Sylvie; Conti, Filoména; Sansonetti, Philippe J; Chamaillard, Mathias; Desreumaux, Pierre; Dubuquoy, Laurent; Mathurin, Philippe

2008-03-01

The recent discovery of bacterial receptors such as NOD2 that contribute to crosstalk between innate and adaptive immune systems in the digestive tract constitutes an important challenge in our understanding of liver injury mechanisms. The present study focuses on NOD2 functions during liver injury. NOD2, TNF-alpha and IFN-gamma mRNA were quantified using real-time PCR in liver samples from patients and mice with liver injury. We evaluated the susceptibility of concanavalin A (ConA) challenge in NOD2-deficient mice (Nod2-/-) compared to wild-type littermates. We tested the effect of muramyl dipeptide (MDP), the specific activator of NOD2, on ConA-induced liver injury in C57BL/6 mice. We studied the cellular distribution and the role of NOD2 in immune cells and hepatocytes. We demonstrated that NOD2, TNF-alpha and IFN-gamma were upregulated during liver injury in mice and humans. Nod2-/- mice were resistant to ConA-induced hepatitis compared to their wild-type littermates, through reduced IFN-gamma production by immune cells. Conversely, administration of MDP exacerbated ConA-induced liver injury. MDP was a strong inducer of IFN-gamma in freshly isolated human PBMC, splenocytes and hepatocytes. Our study supports the hypothesis that NOD2 contributes to liver injury via a regulatory mechanism affecting immune cells infiltrating the liver and hepatocytes. Taken together, our results indicate that NOD2 may represent a new therapeutic target in liver diseases.

Inhibitory spectrum of alpha 2-plasmin inhibitor.

PubMed Central

Saito, H; Goldsmith, G H; Moroi, M; Aoki, N

1979-01-01

alpha 2-Plasmin inhibitor (alpha 2PI) has been recently characterized as a fast-reacting inhibitor of plasmin in human plasma and appears to play an important role in the regulation of fibrinolysis in vivo. We have studied the effect of purified alpha 2PI upon various proteases participating in human blood coagulation and kinin generation. At physiological concentration (50 microgram/ml), alpha 2PI inhibited the clot-promoting and prekallikrein-activating activity of Hageman factor fragments, the amidolytic, kininogenase, and clot-promoting activities of plasma kallikrein, and the clot-promoting properties of activated plasma thromboplastin antecedent (PTA, Factor XIa) and thrombin. alpha 2PI had minimal inhibitory effect on surface-bound activated PTA and activated Stuart factor (Factor Xa). alpha 2PI did not inhibit the activity of activated Christmas factor (Factor IXa) or urinary kallikrein. Heparin (1.5-2.0 units/ml) did not enhance the inhibitory function of alpha 2PI. These results suggest that, like other plasma protease inhibitors, alpha 2PI possesses a broad in vitro spectrum of inhibitory properties. PMID:156364

d-Limonene-induced male rat-specific nephrotoxicity: Evaluation of the association between d-limonene and alpha 2u-globulin

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

Lehman-McKeeman, L.D.; Rodriguez, P.A.; Takigiku, R.

1989-06-15

d-Limonene is a naturally occurring monoterpene, which when dosed orally, causes a male rat-specific nephrotoxicity manifested acutely as the exacerbation of protein droplets in proximal tubule cells. Experiments were conducted to examine the retention of (/sup 14/C)d-limonene in male and female rat kidney, to determine whether d-limonene or one or more of its metabolites associates with the male rat-specific protein, alpha 2u-globulin, and if so, to identify the bound material. The results indicated that, 24 hr after oral administration of 3 mmol d-limonene/kg, the renal concentration of d-limonene equivalents was approximately 2.5 times higher in male rats than in femalemore » rats. Equilibrium dialysis in the presence or absence of sodium dodecyl sulfate indicated that approximately 40% of the d-limonene equivalents in male rat kidney associated with proteins in a reversible manner, whereas no significant association was observed between d-limonene equivalents and female rat kidney proteins. Association between d-limonene and male rat kidney proteins was characterized by high-performance gel filtration and reverse-phase chromatography. Gel filtration HPLC indicated that d-limonene in male rat kidney is associated with a protein fraction having a molecular weight of approximately 20,000. Separation of alpha 2u-globulin from other kidney proteins by reverse-phase HPLC indicated that d-limonene associated with a protein present only in male rat kidney which was definitively identified as alpha 2u-globulin by amino acid sequencing. The major metabolite associated with alpha 2u-globulin was d-limonene-1,2-oxide. Parent d-limonene was also identified as a minor component in the alpha 2u-globulin fraction.« less

Hyperglycemia and oxidized-LDL exert a deleterious effect on endothelial progenitor cell migration in type 2 diabetes mellitus.

PubMed

Hamed, Saher; Brenner, Benjamin; Abassi, Zaid; Aharon, Anat; Daoud, Deeb; Roguin, Ariel

2010-09-01

Type 2 diabetes mellitus (DM) patients with coronary artery disease (CAD) have elevated plasma oxidized-LDL (OxLDL) levels and impaired neovascularization. Hyperglycemia and hyperlipidemia impair endothelial progenitor cell (EPC) migration, and endothelial nitric oxide (NO) bioavailability and NO synthase (NOS) activity are essential for EPC migration. Stromal-derived factor-1alpha (SDF1alpha) contributes to EPC mobilization and homing by stimulating the CXC receptor-4 (CXCR4) on the EPC plasmalemma to activate the Pi3K/Akt/eNOS signaling pathway. Therefore, we investigated the effect of high glucose (HG) and OxLDL on the migration and NO bioavailability of EPCs from healthy individuals, and then correlated the findings with those of EPCs from type 2 DM patients with and without CAD. EPCs from 15 healthy and 55 patients were exposed to HG, OxLDL, or both before evaluating EPC count, migration and NO production, and expression of CXCR4 and members of Pi3K/Akt/eNOS signaling cascade. Counts, migration, CXCR4 expression, and NO production were significantly reduced in EPCs from DM and CAD patients compared with that obtained in EPCs from healthy, and were further reduced in DM patients with CAD. The expression of CXCR4 and activation of Pi3K/Akt/eNOS signaling cascade were suppressed in OxLDL- and HG-treated EPCs, and this suppression was exacerbated when EPCs were treated simultaneously with HG and OxLDL. Hyperglycemia and elevated circulating OxLDL in DM patients with CAD severely impair EPC migration. These results suggest that the underlying mechanism for this impaired EPC migration is linked to the CXCR4/Pi3K/Akt/eNOS signaling pathway. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Lesion Size Is Exacerbated in Hypoxic Rats Whereas Hypoxia-Inducible Factor-1 Alpha and Vascular Endothelial Growth Factor Increase in Injured Normoxic Rats: A Prospective Cohort Study of Secondary Hypoxia in Focal Traumatic Brain Injury.

PubMed

Thelin, Eric Peter; Frostell, Arvid; Mulder, Jan; Mitsios, Nicholas; Damberg, Peter; Aski, Sahar Nikkhou; Risling, Mårten; Svensson, Mikael; Morganti-Kossmann, Maria Cristina; Bellander, Bo-Michael

2016-01-01

Hypoxia following traumatic brain injury (TBI) is a severe insult shown to exacerbate the pathophysiology, resulting in worse outcome. The aim of this study was to investigate the effects of a hypoxic insult in a focal TBI model by monitoring brain edema, lesion volume, serum biomarker levels, immune cell infiltration, as well as the expression of hypoxia-inducible factor-1 alpha (HIF-1α) and vascular endothelial growth factor (VEGF). Female Sprague-Dawley rats (n = 73, including sham and naive) were used. The rats were intubated and mechanically ventilated. A controlled cortical impact device created a 3-mm deep lesion in the right parietal hemisphere. Post-injury, rats inhaled either normoxic (22% O2) or hypoxic (11% O2) mixtures for 30 min. The rats were sacrificed at 1, 3, 7, 14, and 28 days post-injury. Serum was collected for S100B measurements using ELISA. Ex vivo magnetic resonance imaging (MRI) was performed to determine lesion size and edema volume. Immunofluorescence was employed to analyze neuronal death, changes in cerebral macrophage- and neutrophil infiltration, microglia proliferation, apoptosis, complement activation (C5b9), IgG extravasation, HIF-1α, and VEGF. The hypoxic group had significantly increased blood levels of lactate and decreased pO2 (p < 0.0001). On MRI post-traumatic hypoxia resulted in larger lesion areas (p = 0.0173), and NeuN staining revealed greater neuronal loss (p = 0.0253). HIF-1α and VEGF expression was significantly increased in normoxic but not in hypoxic animals (p < 0.05). A trend was seen for serum levels of S100B to be higher in the hypoxic group at 1 day after trauma (p = 0.0868). No differences were observed between the groups in cytotoxic and vascular edema, IgG extravasation, neutrophils and macrophage aggregation, microglia proliferation, or C5b-9 expression. Hypoxia following focal TBI exacerbated the lesion size and neuronal loss. Moreover, there was a tendency to higher levels of S100B in the hypoxic group early after injury, indicating a potential validity as a biomarker of injury severity. In the normoxic group, the expression of HIF-1α and VEGF was found elevated, possibly indicative of neuro-protective responses occurring in this less severely injured group. Further studies are warranted to better define the pathophysiology of post-TBI hypoxia.

Granulocyte-macrophage colony-stimulating factor amplification of interleukin-1beta and tumor necrosis factor alpha production in THP-1 human monocytic cells stimulated with lipopolysaccharide of oral microorganisms.

PubMed

Baqui, A A; Meiller, T F; Chon, J J; Turng, B F; Falkler, W A

1998-05-01

Cytokines, including granulocyte-macrophage colony-stimulating factor (GM-CSF), are used to assist in bone marrow recovery during cancer chemotherapy. Interleukin-1beta (IL-1beta) and tumor necrosis factor alpha (TNF-alpha) play important roles in inflammatory processes, including exacerbation of periodontal diseases, one of the most common complications in patients who undergo this therapy. A human monocyte cell line (THP-1) was utilized to investigate IL-1beta and TNF-alpha production following GM-CSF supplementation with lipopolysaccharide (LPS) from two oral microorganisms, Porphyromonas gingivalis and Fusobacterium nucleatum. LPS of P. gingivalis or F. nucleatum was prepared by a phenol-water extraction method and characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and determination of total protein and endotoxin contents. Resting THP-1 cells were treated with LPS of P. gingivalis or F. nucleatum and/or GM-CSF (50 IU/ml) by using different concentrations for various time periods. Production of IL-1beta and TNF-alpha in THP-1 cells was measured by solid-phase enzyme-linked immunosorbent assay. Reverse transcription (RT)-PCR was used to evaluate the gene expression of resting and treated THP-1 cells. IL-1beta was not detected in untreated THP-1 cells. IL-1beta production was, however, stimulated sharply at 4 h. GM-CSF amplified IL-1beta production in THP-1 cells treated with LPS from both oral anaerobes. No IL-1beta-specific mRNA transcript was detected in untreated THP-1 cells. However, IL-1beta mRNA was detected by RT-PCR 2 h after stimulation of THP-1 cells with LPS from both organisms. GM-CSF did not shorten the IL-1beta transcriptional activation time. GM-CSF plus F. nucleatum or P. gingivalis LPS activated THP-1 cells to produce a 1.6-fold increase in TNF-alpha production at 4 h over LPS stimulation alone. These investigations with the in vitro THP-1 model indicate that there may be an increase in the cellular immune response to oral endotoxin following GM-CSF therapy, as evidenced by production of the tissue-reactive cytokines IL-1beta and TNF-alpha.

Influence of deoxynivalenol on NF-kappaB activation and IL-8 secretion in human intestinal Caco-2 cells.

PubMed

Van De Walle, Jacqueline; Romier, Béatrice; Larondelle, Yvan; Schneider, Yves-Jacques

2008-04-01

Deoxynivalenol (DON) is the most prevalent trichothecene mycotoxin in crops in Europe and North America. In human intestinal Caco-2 cells, DON activates the mitogen-activated protein kinases (MAPKs). We hypothesized a link between DON ingestion and intestinal inflammation, and used Caco-2 cells to assess the effects of DON, at plausible intestinal concentrations (250-10,000 ng/ml), on inflammatory mediators acting downstream the MAPKs cascade i.e. activation of nuclear factor-kappaB (NF-kappaB) and interleukin-8 (IL-8) secretion. In addition, Caco-2 cells were co-exposed to pro-inflammatory stimuli in order to mimic an inflamed intestinal epithelium. Dose-dependent increases in NF-kappaB activity and IL-8 secretion were observed, reaching 1.4- and 7.6-fold, respectively using DON at 10 microg/ml. Phosphorylation of inhibitor-kappaB (IkappaB) increased (1.6-fold) at DON levels <0.5 microg/ml. Exposure of Caco-2 cells to pro-inflammatory agents, i.e. 25 ng/ml interleukin-1beta, 100 ng/ml tumor necrosis factor-alpha or 10 microg/ml lipopolysaccharides, activated NF-kappaB and increased IL-8 secretion. Synergistic interactions between these stimuli and DON were observed. These data show that DON induces NF-kappaB activation and IL-8 secretion dose-dependently in Caco-2 cells, and this effect was accentuated upon pro-inflammatory stimulation, suggesting DON exposure could cause or exacerbate intestinal inflammation.

Exacerbation-related impairment of quality of life and work productivity in severe and very severe chronic obstructive pulmonary disease.

PubMed

Solem, Caitlyn T; Sun, Shawn X; Sudharshan, Lavanya; Macahilig, Cynthia; Katyal, Monica; Gao, Xin

2013-01-01

Exacerbation-associated health-related quality of life (HRQoL) in patients with severe and very severe chronic obstructive pulmonary disease (COPD) is ill-defined. This study describes patterns, HRQoL, and the work productivity impact of COPD-related moderate and SEV exacerbations in patients with SEV/VSEV COPD, focusing on the chronic bronchitis subtype. A US sample of SEV and VSEV COPD patients with recent moderate or SEV exacerbation was recruited. Along with the demographic and clinical data collected from medical records, patients reported on exacerbation frequency, health-related quality of life (HRQoL) (using the St George's Respiratory Questionnaire for COPD [SGRQ-C] and the European Quality of Life-5 Dimensions [EQ-5D]™ index), and work productivity and activity impairment (using the Work Productivity and Activity Impairment Questionnaire - Specific Health Problem [WPAI-SHP]). The HRQoL-related impacts of exacerbation frequency, time since exacerbation, and last exacerbation severity were evaluated via linear regressions. A total of 314 patients (190 SEV/124 VSEV, mean age =68.0 years, 51% male, 28% current smokers) were included. In the previous 12 months, patients reported an average of 1.8 moderate exacerbations and 0.9 SEV exacerbations. Overall, 16% of patients were employed and reported a high percentage of overall work impairment (42.4% ± 31.1%). Activity impairment was positively associated with recent exacerbation severity (SEV 64.6% ± 26.8% versus moderate 55.6% ± 28.2%) (P=0.006). The HRQoL was significantly worse for SEV versus VSEV COPD (EQ-5D: 0.62 ± 0.23 versus 0.70 ± 0.17, respectively, and SGRQ-C: 70.1 ± 21.3 versus 61.1 ± 19.0, respectively) (P<0.001). Worse current HRQoL was reported by patients with a SEV versus moderate recent exacerbation (EQ-5D: 0.63 ± 0.21 versus 0.70 ± 0.20, respectively) (P=0.003); SGRQ-C: 70.3 ± 19.9 versus 61.7 ± 20.1, respectively (P<0.001). One additional exacerbation in the previous 12 months was associated with a 2.4-point SGRQ-C increase and a 0.02-point EQ-5D index decrease. The severity and frequency of COPD-related moderate/SEV exacerbations in SEV and VSEV COPD patients were positively associated with poor HRQoL and work productivity and activity impairment.

Frequency of self-reported COPD exacerbation and airflow obstruction in five Latin American cities: the Proyecto Latinoamericano de Investigacion en Obstruccion Pulmonar (PLATINO) study.

PubMed

Montes de Oca, Maria; Tálamo, Carlos; Halbert, Ronald J; Perez-Padilla, Rogelio; Lopez, Maria Victorina; Muiño, Adriana; Jardim, José Roberto B; Valdivia, Gonzalo; Pertuzé, Julio; Moreno, Dolores; Menezes, Ana Maria B

2009-07-01

Recurrent exacerbations are common in COPD patients. Limited information exists regarding exacerbation frequency in COPD patients from epidemiologic studies. We examined the frequency of self-reported exacerbations and the factors influencing exacerbation frequency among COPD patients in a population-based study conducted in Latin America. We used a post-bronchodilator FEV(1)/FVC ratio of < 0.70 to define COPD. Exacerbation was self-reported and defined by symptoms (deterioration of breathing symptoms that affected usual daily activities or caused missed work). Spirometry was performed in 5,314 subjects. There were 759 subjects with airflow limitation; of these, 18.2% reported ever having had an exacerbation, 7.9% reported having an exacerbation, and 6.2% reported having an exacerbation requiring at least a doctor visit within the past year. The proportion of individuals with an exacerbation significantly increased by Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages, from 4.2% in stage 1 to 28.9% in stages 3 and 4. The self-reported exacerbation rate was 0.58 exacerbations per year. The rate of exacerbations requiring at least a doctor visit and length of stay in hospital due to exacerbations also increased as COPD severity progressed. The factors associated with having an exacerbation in the past year were dyspnea, prior asthma diagnosis, receiving any respiratory therapy, and disease severity of GOLD stages 3 and 4. The proportion of individuals with airflow limitation and self-reported exacerbation increases as the disease severity progresses. Dyspnea, prior asthma diagnosis, receiving any respiratory therapy, and more severe obstruction were significantly associated with having an exacerbation in the past year.

Endotoxin-induced lethality in neonatal mice is counteracted by interleukin-10 (IL-10) and exacerbated by anti-IL-10.

PubMed Central

Nicoletti, F; Mancuso, G; Ciliberti, F A; Beninati, C; Carbone, M; Franco, S; Cusumano, V

1997-01-01

The lethal effects occurring in neonatal (<24-h-old) BALB/c mice after challenge with 25 mg of lipopolysaccharide (LPS) per kg of body weight were significantly counteracted by pretreatment with recombinant interleukin-10 (rIL-10; 25 or 50 ng/mouse). Concordantly, blockage of endogenous IL-10 with the SXC1 monoclonal antibody increased LPS-induced mortality. Both IL-10 and SXC1 modulated the release of tumor necrosis factor alpha (TNF-alpha) so that, relative to controls, peak TNF-alpha values after LPS challenge were decreased by rIL-10 and increased by anti-IL-10. PMID:9302214

Evaluation of the alpha-1 and alpha-2 adrenoceptor-mediated effects of a series of dimethoxy-substituted tolazoline derivatives in the cardiovascular system of the pithed rat.

PubMed

Ruffolo, R R; Messick, K

1985-01-01

The alpha-1 and alpha-2 adrenoceptor-mediated effects of a series of dimethoxy-substituted tolazoline derivatives were investigated in the cardiovascular system of the pithed rat. The 2,5- and 3,5-dimethoxy-substituted tolazoline derivatives produced vasopressor responses that were inhibited by the alpha-1 adrenoceptor antagonist, prazosin (0.1 mg/kg i.v.), and were not affected by the alpha-2 adrenoceptor antagonist, yohimbine (1 mg/kg i.v.), suggesting that these derivatives selectively activate postsynaptic vascular alpha-1 adrenoceptors. The 2,5- and 3,5-dimethoxy-substituted derivatives of tolazoline did not produce an alpha-2 adrenoceptor-mediated inhibition of neurogenic tachycardia in cord-stimulated pithed rats and were therefore presumed to be devoid of alpha-2 adrenoceptor agonist activity. In contrast, 2,3-dimethoxytolazoline produced a vasopressor effect that was inhibited by yohimbine but not by prazosin, suggesting selective activation of postsynaptic vascular alpha-2 adrenoceptors. Consistent with this observation is the fact that 2,3-dimethoxytolazoline elicited a dose-dependent, alpha-2 adrenoceptor-mediated inhibition of neurogenic tachycardia in cord-stimulated pithed rat. 3,4-Dimethoxytolazoline was a weak alpha-1 adrenoceptor agonist in the vasculature of the pithed rat and was devoid of agonist activity at alpha-2 adrenoceptors. However, 3,4-dimethoxytolazoline was found to be an alpha-2 adrenoceptor antagonist of similar potency as yohimbine. The results of the present study indicate that dimethoxy-substituted derivatives of tolazoline possess different activities and selectivities at alpha-1 and alpha-2 adrenoceptors depending upon the positions of substitution.(ABSTRACT TRUNCATED AT 250 WORDS)

Pesticide exposure exacerbates alpha-synucleinopathy in an A53T transgenic mouse model.

PubMed

Norris, Erin H; Uryu, Kunihiro; Leight, Susan; Giasson, Benoit I; Trojanowski, John Q; Lee, Virginia M-Y

2007-02-01

The factors initiating or contributing to the pathogenesis of Parkinson's disease and related neurodegenerative synucleinopathies are still largely unclear, but environmental factors such as pesticides have been implicated. In this study, A53T mutant human alpha-synuclein transgenic mice (M83), which develop alpha-synuclein neuropathology, were treated with the pesticides paraquat and maneb (either singly or together), and their effects were analyzed. Immunohistochemical and biochemical analyses showed that chronic treatment of M83 transgenic mice with both pesticides (but not with either pesticide alone) drastically increased neuronal alpha-synuclein pathology throughout the central nervous system including the hippocampus, cerebellum, and sensory and auditory cortices. alpha-Synuclein-associated mitochondrial degeneration was observed in M83 but not in wild-type alpha-synuclein transgenic mice. Because alpha-synuclein inclusions accumulated in pesticide-exposed M83 transgenic mice without a motor phenotype, we conclude that alpha-synuclein aggregate formation precedes disease onset. These studies support the notion that environmental factors causing nitrative damage are closely linked to mechanisms underlying the formation of alpha-synuclein pathologies and the onset of Parkinson's-like neurodegeneration.

Involvement of estrogen receptor variant ER-alpha36, not GPR30, in nongenomic estrogen signaling.

PubMed

Kang, Lianguo; Zhang, Xintian; Xie, Yan; Tu, Yaping; Wang, Dong; Liu, Zhenming; Wang, Zhao-Yi

2010-04-01

Accumulating evidence suggested that an orphan G protein-coupled receptor (GPR)30, mediates nongenomic responses to estrogen. The present study was performed to investigate the molecular mechanisms underlying GPR30 function. We found that knockdown of GPR30 expression in breast cancer SK-BR-3 cells down-regulated the expression levels of estrogen receptor (ER)-alpha36, a variant of ER-alpha. Introduction of a GPR30 expression vector into GPR30 nonexpressing cells induced endogenous ER-alpha36 expression, and cotransfection assay demonstrated that GPR30 activated the promoter activity of ER-alpha36 via an activator protein 1 binding site. Both 17beta-estradiol (E2) and G1, a compound reported to be a selective GPR30 agonist, increased the phosphorylation levels of the MAPK/ERK1/2 in SK-BR-3 cells, which could be blocked by an anti-ER-alpha36-specific antibody against its ligand-binding domain. G1 induced activities mediated by ER-alpha36, such as transcription activation activity of a VP16-ER-alpha36 fusion protein and activation of the MAPK/ERK1/2 in ER-alpha36-expressing cells. ER-alpha36-expressing cells, but not the nonexpressing cells, displayed high-affinity, specific E2 and G1 binding, and E2- and G1-induced intracellular Ca(2+) mobilization only in ER-alpha36 expressing cells. Taken together, our results demonstrated that previously reported activities of GPR30 in response to estrogen were through its ability to induce ER-alpha36 expression. The selective G protein-coupled receptor (GPR)30 agonist G1 actually interacts with ER-alpha36. Thus, the ER-alpha variant ER-alpha36, not GPR30, is involved in nongenomic estrogen signaling.

Stress exacerbates pain in the everyday lives of women with fibromyalgia syndrome--The role of cortisol and alpha-amylase.

PubMed

Fischer, Susanne; Doerr, Johanna M; Strahler, Jana; Mewes, Ricarda; Thieme, Kati; Nater, Urs M

2016-01-01

Although fibromyalgia syndrome (FMS) is a chronic condition, its cardinal symptom pain is known to fluctuate over the day. Stress has often been claimed to exacerbate pain; however, there is barely any evidence on whether or not this is true on a day-to-day basis (and, alternatively, on whether pain leads to increased stress levels). Using an ecologically valid measurement design, we tested whether and how stress and pain are intertwined in participants with FMS. We additionally examined the role of the two major stress-responsive systems, the hypothalamic-pituitary-adrenal axis and the autonomic nervous system, as potential mediators of this relationship. An ambulatory assessment study was conducted over the course of 14 days. On each day, 32 females with FMS provided six diary entries on momentary stress and pain levels. Saliva samples were collected at the same time points to determine cortisol and alpha-amylase as indicators of stress-responsive systems. Higher stress at a given measurement time point was associated with higher reported pain levels at the subsequent time point (UC=1.47, p<0.001), but not vice versa (UC<0.01, p=0.179). The stress-pain relationship was neither mediated by momentary cortisol nor by alpha-amylase; however, momentary cortisol was independently associated with momentary pain (UC=0.27, p=0.009). Stress seems to be a powerful exacerbating factor for pain as experienced by patients with FMS in their everyday lives. Cortisol may be involved in the diurnal fluctuation of pain levels in patients with FMS. Future studies should identify relevant daily stressors in persons with FMS and scrutinize the mechanisms underlying the cortisol-pain relationship. Copyright © 2015 Elsevier Ltd. All rights reserved.

[The changes of alpha 2-plasmin inhibitor, and notably urokinase activities in blood measured by synthetic chromogenic substrates S-2444 after urokinase administration].

PubMed

Itoh, Y; Tsuji, K; Tanaka, N; Yamada, M; Nakanishi, M; Ishihara, M; Kobayashi, M

1983-01-01

Thrombolytic therapy with Urokinase (UK) has often been successful but it is very difficult to determine the effective dosage of UK. It is reported that after UK administration, plasmin fibrinolytic activity was immediately inhibited by alpha 2-Plasmin inhibitor (alpha 2-PI). In this study, we used UK on patients with myoma to prevent the occurrence of thrombosis after operation and the initial decrease in alpha 2-PI activities following UK administration was investigated to determine the minimum effective dosage of UK required to suppress alpha 2-PI. An attempt was also made to measure UK activity in blood by means of chromogenic substrate S-2444, and in some cases by administering 60,000 I.U. UK, alpha 1-Antitrypsin (alpha 1-AT), alpha 2-Macroglobulin (alpha 2-M), Antithrombin III (AT III) and Plasminogen (Plg) were measured at the same time. The results were as follows: 1) By the drip infusion method. In all doses, alpha 2-PI and UK activity showed no remarkable change. 2) By the one shot method. a) A decrease in alpha 2-PI was observed following both 48,000 and 60,000 I.U. UK administration. It was noted that in the case of 48,000 I.U. UK, alpha 2-PI showed the lowest level, 60% of the pre-administration level. b) UK activity showed a gradual increase in the case of 60,000 I.U. UK only and large changes in the other cases. c) alpha 1-AT, alpha 2-M, AT III and Plg produced no remarkable changes. This indicated that the effective dosage of UK for suppressing alpha 2-PI was at least 48,000 I.U. UK with the one shot method, and alpha 2-PI is a reliable indicator of the effectiveness of UK therapy.

Toxicity of trichlorotoluene isomers: a 28-day feeding study in the rat.

PubMed

Chu, I; Shen, S Y; Villeneuve, D C; Secours, V E; Valli, V E

1984-03-01

Groups of 10 male and 10 female rats were fed alpha,alpha,alpha-, alpha,2,6- or 2,3,6- trichlorotoluene (TCT) in their diet at 0, 0.5, 5.0, 50 or 500 ppm for 28 days. Growth rate and food consumption were not affected by treatment. No deaths occurred. Significant increases in liver weights were observed in male rats fed 5.0 and 500 ppm 2,3,6-TCT. Mild serum biochemical changes occurred in male rats. These included increased SDH activities in the groups fed 5.0 and 50 ppm alpha, alpha, alpha-TCT, and 5.0 ppm 2,3,6-TCT. Alpha, alpha, alpha-TCT at 500 ppm caused elevated LDH activities in male rats. Hepatic microsomal aminopyrine N-demethylase activities were increased in male rats fed 500 ppm alpha,2,6-TCT. Hematological parameters were not affected by treatment. Mild histological changes were seen in the liver, kidney and thyroid of treated rats. Data presented here suggest that alpha, alpha, alpha-, alpha,2,6- and 2,3,6-TCT possess a low order of oral toxicity in the rat.

Alpha-amylase Inhibition and Antioxidant Activity of Marine Green Algae and its Possible Role in Diabetes Management.

PubMed

Unnikrishnan, P S; Suthindhiran, K; Jayasri, M A

2015-10-01

In the continuing search for safe and efficient antidiabetic drug, marine algae become important source which provide several compounds of immense therapeutic potential. Alpha-amylase, alpha-glucosidase inhibitors, and antioxidant compounds are known to manage diabetes and have received much attention recently. In the present study, four green algae (Chaetomorpha aerea, Enteromorpha intestinalis, Chlorodesmis, and Cladophora rupestris) were chosen to evaluate alpha-amylase, alpha-glucosidase inhibitory, and antioxidant activity in vitro. The phytochemical constituents of all the extracts were qualitatively determined. Antidiabetic activity was evaluated by inhibitory potential of extracts against alpha-amylase and alpha-glucosidase by spectrophotometric assays. Antioxidant activity was determined by 2,2-diphenyl-1-picrylhydrazyl, hydrogen peroxide (H2O2), and nitric oxide scavenging assay. Gas chromatography-mass spectrometry (GC-MS) analysis was carried out to determine the major compound responsible for its antidiabetic action. Among the various extracts screened, chloroform extract of C. aerea (IC50 - 408.9 μg/ml) and methanol extract of Chlorodesmis (IC50 - 147.6 μg/ml) showed effective inhibition against alpha-amylase. The extracts were also evaluated for alpha-glucosidase inhibition, and no observed activity was found. Methanol extract of C. rupestris showed notable free radical scavenging activity (IC50 - 666.3 μg/ml), followed by H2O2 (34%) and nitric oxide (49%). Further, chemical profiling by GC-MS revealed the presence of major bioactive compounds. Phenol, 2,4-bis (1,1-dimethylethyl) and z, z-6,28-heptatriactontadien-2-one were predominantly found in the methanol extract of C. rupestris and chloroform extract of C. aerea. Our results demonstrate that the selected algae exhibit notable alpha-amylase inhibition and antioxidant activity. Therefore, characterization of active compounds and its in vivo assays will be noteworthy. Four green algae were chosen to evaluate alpha-amylase, alpha-glucosidase inhibitory, and antioxidant activity in vitro C. aerea and Chlorodesmis showed significant inhibition against alpha-amylase, and C. rupestris showed notable free radical scavenging activityNo observed activity was found against alpha-glucosidaseGC-MS analysis of the active extracts reveals the presence of major compounds which gives an insight on the antidiabetic and antioxidant activity of these algae. Abbreviations used: DPPH: 2,2-diphenyl-1-picrylhydrazyl, BHT: Butylated hydroxytoluene, GC-MS: Gas chromatography-mass spectrometry.

Alpha-amylase Inhibition and Antioxidant Activity of Marine Green Algae and its Possible Role in Diabetes Management

PubMed Central

Unnikrishnan, P. S.; Suthindhiran, K.; Jayasri, M. A.

2015-01-01

Aim: In the continuing search for safe and efficient antidiabetic drug, marine algae become important source which provide several compounds of immense therapeutic potential. Alpha-amylase, alpha-glucosidase inhibitors, and antioxidant compounds are known to manage diabetes and have received much attention recently. In the present study, four green algae (Chaetomorpha aerea, Enteromorpha intestinalis, Chlorodesmis, and Cladophora rupestris) were chosen to evaluate alpha-amylase, alpha-glucosidase inhibitory, and antioxidant activity in vitro. Materials and Methods: The phytochemical constituents of all the extracts were qualitatively determined. Antidiabetic activity was evaluated by inhibitory potential of extracts against alpha-amylase and alpha-glucosidase by spectrophotometric assays. Antioxidant activity was determined by 2,2-diphenyl-1-picrylhydrazyl, hydrogen peroxide (H2O2), and nitric oxide scavenging assay. Gas chromatography-mass spectrometry (GC-MS) analysis was carried out to determine the major compound responsible for its antidiabetic action. Results: Among the various extracts screened, chloroform extract of C. aerea (IC50 − 408.9 μg/ml) and methanol extract of Chlorodesmis (IC50 − 147.6 μg/ml) showed effective inhibition against alpha-amylase. The extracts were also evaluated for alpha-glucosidase inhibition, and no observed activity was found. Methanol extract of C. rupestris showed notable free radical scavenging activity (IC50 – 666.3 μg/ml), followed by H2O2 (34%) and nitric oxide (49%). Further, chemical profiling by GC-MS revealed the presence of major bioactive compounds. Phenol, 2,4-bis (1,1-dimethylethyl) and z, z-6,28-heptatriactontadien-2-one were predominantly found in the methanol extract of C. rupestris and chloroform extract of C. aerea. Conclusion: Our results demonstrate that the selected algae exhibit notable alpha-amylase inhibition and antioxidant activity. Therefore, characterization of active compounds and its in vivo assays will be noteworthy. SUMMARY Four green algae were chosen to evaluate alpha-amylase, alpha-glucosidase inhibitory, and antioxidant activity in vitro C. aerea and Chlorodesmis showed significant inhibition against alpha-amylase, and C. rupestris showed notable free radical scavenging activityNo observed activity was found against alpha-glucosidaseGC-MS analysis of the active extracts reveals the presence of major compounds which gives an insight on the antidiabetic and antioxidant activity of these algae. Abbreviations used: DPPH: 2,2-diphenyl-1-picrylhydrazyl, BHT: Butylated hydroxytoluene, GC-MS: Gas chromatography-mass spectrometry. PMID:27013787

Vitamin E antagonizes ozone-induced asthma exacerbation in Balb/c mice through the Nrf2 pathway.

PubMed

Duan, Liju; Li, Jinquan; Ma, Ping; Yang, Xu; Xu, Shunqing

2017-09-01

Millions of people are regularly exposed to ozone, a gas known to contribute significantly to worsening the symptoms of patients with asthma. However, the mechanisms underlying these ozone exacerbation effects are not fully understood. In this study, we examined the exacerbation effect of ozone in OVA-induced asthma mice and tried to demonstrate the protective mechanism of vitamin E (VE). An asthma mouse model was established, and used to identify the exacerbating effects of ozone by assessing cytokine and serum immunoglobulin concentrations, airway leukocyte infiltration, histopathological changes in lung tissues, and airway hyper-responsiveness. We then determined the amount of reactive oxygen species (ROS) accumulated, the extent to which VE induced ROS elimination, and examined the antagonistic effects of VE on the ozone-induced exacerbating effects. This study showed that 1-ppm ozone exposure could exacerbate OVA-induced asthma in mice. More importantly we found that ozone induced oxidative stress in asthmatic airways may lead to the inhibition of Nuclear factor-erythroid 2-related factor 2 (Nrf2), and may subsequently induce even more exaggerated oxidative stress associated with asthma exacerbation. Through VE induced Nrf2 activation and the subsequent increase in Nrf2 target protein expression, this study suggests a novel mechanism for alleviating ozone exacerbated asthma symptoms. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hyperglycemia-conditioned increase in alpha-2-macroglobulin in healthy normal subjects: a phenomenon correlated with deficient antithrombin III activity.

PubMed

Ceriello, A; Quatraro, A; Dello Russo, P; Marchi, E; Barbanti, M; Giugliano, D

1989-01-01

Induced hyperglycemia in normal subjects increases alpha 2-macroglobulin (alpha 2M) activity and alpha 2M concentration and reduces antithrombin III (ATIII) activity, while it does not affect ATIII plasma concentration. Hyperglycemia-determined variations in ATIII activity and alpha 2M molecules are correlated in an inverse and parallel fashion. A compensatory role for the increase in alpha 2M in the regulation of the coagulation system may be hypothesized. Moreover, these data provide evidence that hyperglycemia may decrease, directly, the biological function of some proteins and may influence the levels of some risk factors for the development of complications in diabetes.

Impact of a Health Management Program on Healthcare Outcomes among Patients on Augmentation Therapy for Alpha 1-Antitrypsin Deficiency: An Insurance Claims Analysis.

PubMed

Campos, Michael A; Runken, Michael C; Davis, Angela M; Johnson, Michael P; Stone, Glenda A; Buikema, Ami R

2018-04-01

Alpha 1-antitrypsin deficiency (AATD) is a genetic disorder which reduces serum alpha 1-antitrypsin (AAT or alpha1-proteinase inhibitor, A1PI) and increases the risk of chronic obstructive pulmonary disease (COPD). Management strategies include intravenous A1PI augmentation, and, in some cases, a health management program (Prolastin Direct ® ; PD). This study compared clinical and economic outcomes between patients with and without PD program participation. This retrospective study included commercial and Medicare Advantage health insurance plan members with ≥ 1 claim with diagnosis codes for COPD and ≥ 1 medical or pharmacy claim including A1PI (on index date). Outcomes were compared between patients receiving only Prolastin ® or Prolastin ® -C (PD cohort) and patients who received a different brand without PD (Comparator cohort). Demographic and clinical characteristics were captured during 6 months pre-index. Post-index exacerbation episodes and healthcare utilization and costs were compared between cohorts. The study sample comprised 445 patients (n = 213 in PD cohort; n = 232 in Comparator cohort), with a mean age 55.5 years, 50.8% male, and 78.9% commercially insured. The average follow-up was 822 days (2.25 years), and the average time on A1PI was 747 days (2.04 years). Few differences were observed in demographic or clinical characteristics. Adjusting for differences in patient characteristics, the rate of severe exacerbation episodes was reduced by 36.1% in the PD cohort. Adjusted total annual all-cause costs were 11.4% lower, and adjusted mean respiratory-related costs were 10.6% lower in the PD cohort than the Comparator cohort. Annual savings in all-cause total costs in the PD cohort relative to the Comparator cohort was US$25,529 per patient, largely due to significantly fewer and shorter hospitalizations. These results suggest that comprehensive health management services may improve both clinical and economic outcomes among patients with COPD and AATD who receive augmentation therapy. Grifols Shared Services of North America, Inc.

[G-protein potentiates the activation of TNF-alpha on calcium-activated potassium channel in ECV304].

PubMed

Lin, L; Zheng, Y; Qu, J; Bao, G

2000-06-01

Observe the effect of tumor necrosis factor-alpha (TNF-alpha) on calcium-activated potassium channel in ECV304 and the possible involvement of G-protein mediation in the action of TNF-alpha. Using the cell-attached configuration of patch clamp technique. (1) the activity of high-conductance calcium-activated potassium channel (BKca) was recorded. Its conductance is (202.54 +/- 16.62) pS; (2) the activity of BKca was potentiated by 200 U/ml TNF-alpha; (3) G-protein would intensify this TNF-alpha activation. TNF-alpha acted on vascular endothelial cell ECV304 could rapidly activate the activity of BKca. Opening of BKca resulted in membrane hyper-polarization which could increase electro-chemical gradient for the resting Ca2+ influx and open leakage calcium channel, thus resting cytoplasmic free Ca2+ concentration could be elevated. G-protein may exert an important regulation in this process.

Adverse cutaneous reactions induced by TNF-alpha antagonist therapy.

PubMed

Borrás-Blasco, Joaquín; Navarro-Ruiz, Andrés; Borrás, Consuelo; Casterá, Elvira

2009-11-01

To review adverse cutaneous drug reactions induced by tumor necrosis factor alpha (TNF-alpha) antagonist therapy. A literature search was performed using PubMed (1996-March 2009), EMBASE, and selected MEDLINE Ovid bibliography searches. All language clinical trial data, case reports, letters, and review articles identified from the data sources were used. Since the introduction of TNF-alpha antagonist, the incidence of adverse cutaneous drug reactions has increased significantly. A wide range of different skin lesions might occur during TNF-alpha antagonist treatment. New onset or exacerbation of psoriasis has been reported in patients treated with TNF-alpha antagonists for a variety of rheumatologic conditions. TNF-alpha antagonist therapy has been associated with a lupus-like syndrome; most of these case reports occurred in patients receiving either etanercept or infliximab. Serious skin reactions such as erythema multiforme, Stevens-Johnson syndrome, and toxic epidermal necrolysis have been reported rarely with the use of TNF-alpha antagonists. As the use of TNF-alpha antagonists continues to increase, the diagnosis and management of cutaneous side effects will become an increasingly important challenge. In patients receiving TNF-alpha antagonist treatment, skin disease should be considered, and clinicians need to be aware of the adverse reactions of these drugs.

Modification of ubiquitin-C-terminal hydrolase-L1 by cyclopentenone prostaglandins exacerbates hypoxic injury

PubMed Central

Liu, Hao; Li, Wenjin; Ahmad, Muzamil; Miller, Tricia M.; Rose, Marie E.; Poloyac, Samuel M.; Uechi, Guy; Balasubramani, Manimalha; Hickey, Robert W.; Graham, Steven H.

2010-01-01

Cyclopentenone prostaglandins (CyPGs), such as 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2), are active prostaglandin metabolites exerting a variety of biological effects that may be important in the pathogenesis of neurological diseases. Ubiquitin-C-terminal hydrolase L1 (UCH-L1) is a brain specific deubiquitinating enzyme whose aberrant function has been linked to neurodegenerative disorders. We report that [15d-PGJ2] detected by quadrapole mass spectrometry (MS) increases in rat brain after temporary focal ischemia, and that treatment with 15d-PGJ2 induces accumulation of ubiquitinated proteins and exacerbates cell death in normoxic and hypoxic primary neurons. 15d-PGJ2 covalently modifies UCH-L1 and inhibits its hydrolase activity. Pharmacologic inhibition of UCH-L1 exacerbates hypoxic neuronal death while transduction with a TAT-UCH-L1 fusion protein protects neurons from hypoxia. These studies indicate UCH-L1 function is important in hypoxic neuronal death and excessive production of CyPGs after stroke may exacerbate ischemic injury by modification and inhibition of UCH-L1. PMID:20933087

Peroxisome proliferator-activated receptor {alpha} agonists modulate Th1 and Th2 chemokine secretion in normal thyrocytes and Graves' disease

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

Antonelli, Alessandro, E-mail: a.antonelli@med.unipi.it; Ferrari, Silvia Martina, E-mail: sm.ferrari@int.med.unipi.it; Frascerra, Silvia, E-mail: lafrasce@gmail.com

2011-07-01

Until now, no data are present about the effect of peroxisome proliferator-activated receptor (PPAR){alpha} activation on the prototype Th1 [chemokine (C-X-C motif) ligand (CXCL)10] (CXCL10) and Th2 [chemokine (C-C motif) ligand 2] (CCL2) chemokines secretion in thyroid cells. The role of PPAR{alpha} and PPAR{gamma} activation on CXCL10 and CCL2 secretion was tested in Graves' disease (GD) and control primary thyrocytes stimulated with interferon (IFN){gamma} and tumor necrosis factor (TNF){alpha}. IFN{gamma} stimulated both CXCL10 and CCL2 secretion in primary GD and control thyrocytes. TNF{alpha} alone stimulated CCL2 secretion, while had no effect on CXCL10. The combination of IFN{gamma} and TNF{alpha} hadmore » a synergistic effect both on CXCL10 and CCL2 chemokines in GD thyrocytes at levels comparable to those of controls. PPAR{alpha} activators inhibited the secretion of both chemokines (stimulated with IFN{gamma} and TNF{alpha}) at a level higher (for CXCL10, about 60-72%) than PPAR{gamma} agonists (about 25-35%), which were confirmed to inhibit CXCL10, but not CCL2. Our data show that CCL2 is modulated by IFN{gamma} and TNF{alpha} in GD and normal thyrocytes. Furthermore we first show that PPAR{alpha} activators inhibit the secretion of CXCL10 and CCL2 in thyrocytes, suggesting that PPAR{alpha} may be involved in the modulation of the immune response in the thyroid.« less

Tumor necrosis factor alpha blockade exacerbates murine psoriasis-like disease by enhancing Th17 function and decreasing expansion of Treg cells.

PubMed

Ma, Hak-Ling; Napierata, Lee; Stedman, Nancy; Benoit, Stephen; Collins, Mary; Nickerson-Nutter, Cheryl; Young, Deborah A

2010-02-01

Patients with psoriasis and psoriatic arthritis respond well to tumor necrosis factor alpha (TNFalpha) blockers in general; however, there is now mounting evidence that a small cohort of patients with rheumatoid arthritis who receive TNFalpha blockers develop psoriasis. This study was undertaken to explore the mechanisms underlying TNFalpha blockade-induced exacerbation of skin inflammation in murine psoriasis-like skin disease. Skin inflammation was induced in BALB/c scid/scid mice after they received CD4+CD45RB(high)CD25- (naive CD4) T cells from donor mice. These mice were treated with either anti-interleukin-12 (anti-IL-12)/23p40 antibody or murine TNFRII-Fc fusion protein and were examined for signs of disease, including histologic features, various cytokine levels in the serum, and cytokine or FoxP3 transcripts in the affected skin and draining lymph node (LN) cells. In a separate study, naive CD4+ T cells were differentiated into Th1 or Th17 lineages with anti-CD3/28 magnetic beads and appropriate cytokines in the presence or absence of TNFalpha. Cytokine gene expression from these differentiated cells was also determined. Neutralization of TNFalpha exacerbated skin inflammation and markedly enhanced the expression of the proinflammatory cytokines IL-1beta, IL-6, IL-17, IL-21, and IL-22 but suppressed FoxP3 expression in the skin and reduced the number of FoxP3-positive Treg cells in the draining LNs. TNFalpha also demonstrated a divergent role during priming and reactivation of naive T cells. These results reveal a novel immunoregulatory role of TNFalpha on Th17 and Treg cells in some individuals, which may account for the exacerbation of skin inflammation in some patients who receive anti-TNF treatments.

[(35)S]-GTPgammaS autoradiography reveals alpha(2) adrenoceptor-mediated G-protein activation in amygdala and lateral septum.

PubMed

Newman-Tancredi, A; Chaput, C; Touzard, M; Millan, M J

2000-04-03

alpha(2)-adrenoceptor-mediated G-protein activation was examined by [(35)S]-GTPgammaS autoradiography. In alpha(2)-adrenoceptor-rich regions (amygdala, lateral septum), noradrenaline stimulated [(35)S]-GTPgammaS binding. These actions were abolished by the selective alpha(2) antagonist, atipamezole. Conversely, in caudate nucleus, which expresses few alpha(2) receptors, noradrenaline-induced stimulation was not inhibited by atipamezole, suggesting that it is not mediated by alpha(2)-adrenoceptors.

Adipocyte-Macrophage Cross-Talk in Obesity.

PubMed

Engin, Ayse Basak

2017-01-01

Obesity is characterized by the chronic low-grade activation of the innate immune system. In this respect, macrophage-elicited metabolic inflammation and adipocyte-macrophage interaction has a primary importance in obesity. Large amounts of macrophages are accumulated by different mechanisms in obese adipose tissue. Hypertrophic adipocyte-derived chemotactic monocyte chemoattractant protein-1 (MCP-1)/C-C chemokine receptor 2 (CCR2) pathway also promotes more macrophage accumulation into the obese adipose tissue. However, increased local extracellular lipid concentrations is a final mechanism for adipose tissue macrophage accumulation. A paracrine loop involving free fatty acids and tumor necrosis factor-alpha (TNF-alpha) between adipocytes and macrophages establishes a vicious cycle that aggravates inflammatory changes in the adipose tissue. Adipocyte-specific caspase-1 and production of interleukin-1beta (IL-1beta) by macrophages; both adipocyte and macrophage induction by toll like receptor-4 (TLR4) through nuclear factor-kappaB (NF-kappaB) activation; free fatty acid-induced and TLR-mediated activation of c-Jun N-terminal kinase (JNK)-related pro-inflammatory pathways in CD11c+ immune cells; are effective in macrophage accumulation and in the development of adipose tissue inflammation. Old adipocytes are removed by macrophages through trogocytosis or sending an "eat me" signal. The obesity-induced changes in adipose tissue macrophage numbers are mainly due to increases in the triple-positive CD11b+ F4/80+ CD11c+ adipose tissue macrophage subpopulation. The ratio of M1-to-M2 macrophages is increased in obesity. Furthermore, hypoxia along with higher concentrations of free fatty acids exacerbates macrophage-mediated inflammation in obesity. The metabolic status of adipocytes is a major determinant of macrophage inflammatory output. Macrophage/adipocyte fatty-acid-binding proteins act at the interface of metabolic and inflammatory pathways. Both macrophages and adipocytes are the sites for active lipid metabolism and signaling.

Temporal and genetic influences on protection against noise-induced hearing loss by hypoxic preconditioning in mice.

PubMed

Gagnon, Patricia M; Simmons, Dwayne D; Bao, Jianxin; Lei, Debin; Ortmann, Amanda J; Ohlemiller, Kevin K

2007-04-01

The protective benefits of hypoxic preconditioning (HPC) against permanent noise-induced hearing loss (NIHL) were investigated in mice. Hypoxia induced by exposure to 8% O2 for 4 h conferred significant protection against damaging broadband noise delivered 24-48 h later in male and female CBA/J (CBA) and CBA/CaJ mice. No protection was found in C57BL/6 (B6) mice, their B6.CAST-Cdh23(CAST) (B6.CAST) congenics, or in CBAxB6 F1 hybrid mice over the same interval, suggesting that the potential for HPC depends on one or a few autosomal recessive alleles carried by CBA-related strains, and is not influenced by the Cdh23 locus. Protection against NIHL in CBA mice was associated with significant up-regulation of hypoxia-inducible factor-1alpha (HIF-1alpha) within the organ of Corti, not found in B6.CAST. In both CBA and B6.CAST mice, some hypoxia-noise intervals shorter than 24 h were associated with exacerbation of NIHL. Cellular cascades underlying the early exacerbation of NIHL by hypoxia are therefore common to both strains, and not mechanistically linked to later protection. Elucidation of the events that underlie HPC, and how these are impacted by genetics, may lead to pharmacologic approaches to mimic HPC, and may help identify individuals with elevated risk of NIHL.

Etanercept Exacerbates Inflammation and Pathology in a Rabbit Model of Active Pulmonary Tuberculosis

PubMed Central

Tsenova, Liana; O'Brien, Paul; Holloway, Jennifer; Peixoto, Blas; Soteropoulos, Patricia; Fallows, Dorothy; Subbian, Selvakumar

2014-01-01

Treatment of chronic inflammatory diseases with tumor necrosis factor alpha (TNF-α) antagonists has been associated with increased risk of tuberculosis (TB). We examined the usefulness of the rabbit model of active pulmonary TB for studying the impact of the human immune modulatory reagent etanercept on the host immune response. Control of Mycobacterium tuberculosis (Mtb) infection, disease pathology, and the global transcriptional response in Mtb-infected lungs of rabbits were studied. Etanercept treatment exacerbated disease pathology and reduced bacillary control in the lungs, compared with infected untreated animals. Reduced collagen and fibrin deposition in the granulomas was associated with significant downregulation of the collagen metabolism and fibrosis network genes and upregulation of genes in the inflammatory response and cell recruitment networks in the lungs of etanercept treated, compared with untreated rabbits. Our results suggest that targeting the TNF-α signaling pathway disrupts the tissue remodeling process, which is required for the formation and maintenance of well-differentiated granulomas and for control of Mtb growth in the lungs. These results validate the use of the rabbit model for investigating the impact of selected human immune modulatory drugs, such as a TNF-α antagonist, on the host immune response and pathogenesis in TB. PMID:24831609

The biological activity of alpha-mangostin, a larvicidal botanic mosquito sterol carrier protein-2 inhibitor.

PubMed

Larson, Ryan T; Lorch, Jeffrey M; Pridgeon, Julia W; Becnel, James J; Clark, Gary G; Lan, Que

2010-03-01

alpha-Mangostin derived from mangosteen was identified as a mosquito sterol carrier protein-2 inhibitor via high throughput insecticide screening, alpha-Mangostin was tested for its larvicidal activity against third instar larvae of six mosquito species, and the median lethal concentration values range from 0.84 to 2.90 ppm. The residual larvicidal activity of alpha-mangostin was examined under semifield conditions. The results indicated that alpha-mangostin was photolytic with a half-life of 53 min in water under full sunlight exposure. The effect of alpha-mangostin on activities of major detoxification enzymes such as P450, glutathione S-transferase, and esterase was investigated. The results showed that alpha-mangostin significantly elevated activities of P450 and glutathione S-transferase in larvae, whereas it suppressed esterase activity. Toxicity of alpha-mangostin against young rats was studied, and there was no detectable adverse effect at dosages as high as 80 mg/kg. This is the first multifaceted study of the biological activity of alpha-mangostin in mosquitoes. The results suggest that alpha-mangostin may be a lead compound for the development of a new organically based mosquito larvicide.

Metabolic adaptation to intermittent fasting is independent of peroxisome proliferator-activated receptor alpha.

PubMed

Li, Guolin; Brocker, Chad N; Yan, Tingting; Xie, Cen; Krausz, Kristopher W; Xiang, Rong; Gonzalez, Frank J

2018-01-01

Peroxisome proliferator-activated receptor alpha (PPARA) is a major regulator of fatty acid oxidation and severe hepatic steatosis occurs during acute fasting in Ppara-null mice. Thus, PPARA is considered an important mediator of the fasting response; however, its role in other fasting regiments such as every-other-day fasting (EODF) has not been investigated. Mice were pre-conditioned using either a diet containing the potent PPARA agonist Wy-14643 or an EODF regimen prior to acute fasting. Ppara-null mice were used to assess the contribution of PPARA activation during the metabolic response to EODF. Livers were collected for histological, biochemical, qRT-PCR, and Western blot analysis. Acute fasting activated PPARA and led to steatosis, whereas EODF protected against fasting-induced hepatic steatosis without affecting PPARA signaling. In contrast, pretreatment with Wy-14,643 did activate PPARA signaling but did not ameliorate acute fasting-induced steatosis and unexpectedly promoted liver injury. Ppara ablation exacerbated acute fasting-induced hypoglycemia, hepatic steatosis, and liver injury in mice, whereas these detrimental effects were absent in response to EODF, which promoted PPARA-independent fatty acid metabolism and normalized serum lipids. These findings indicate that PPARA activation prior to acute fasting cannot ameliorate fasting-induced hepatic steatosis, whereas EODF induced metabolic adaptations to protect against fasting-induced steatosis without altering PPARA signaling. Therefore, PPARA activation does not mediate the metabolic adaptation to fasting, at least in preventing acute fasting-induced steatosis. Published by Elsevier GmbH.

Protective mechanical ventilation does not exacerbate lung function impairment or lung inflammation following influenza A infection.

PubMed

Zosky, Graeme R; Cannizzaro, Vincenzo; Hantos, Zoltan; Sly, Peter D

2009-11-01

The degree to which mechanical ventilation induces ventilator-associated lung injury is dependent on the initial acute lung injury (ALI). Viral-induced ALI is poorly studied, and this study aimed to determine whether ALI induced by a clinically relevant infection is exacerbated by protective mechanical ventilation. Adult female BALB/c mice were inoculated with 10(4.5) plaque-forming units of influenza A/Mem/1/71 in 50 microl of medium or medium alone. This study used a protective ventilation strategy, whereby mice were anesthetized, tracheostomized, and mechanically ventilated for 2 h. Lung mechanics were measured periodically throughout the ventilation period using a modification of the forced oscillation technique to obtain measures of airway resistance and coefficients of tissue damping and tissue elastance. Thoracic gas volume was measured and used to obtain specific airway resistance, tissue damping, and tissue elastance. At the end of the ventilation period, a bronchoalveolar lavage sample was collected to measure inflammatory cells, macrophage inflammatory protein-2, IL-6, TNF-alpha, and protein leak. Influenza infection caused significant increases in inflammatory cells, protein leak, and deterioration in lung mechanics that were not exacerbated by mechanical ventilation, in contrast to previous studies using bacterial and mouse-specific viral infection. This study highlighted the importance of type and severity of lung injury in determining outcome following mechanical ventilation.

Asthma Exacerbations and Unconventional Natural Gas Development in the Marcellus Shale

PubMed Central

Rasmussen, Sara G.; Ogburn, Elizabeth L.; McCormack, Meredith; Casey, Joan A.; Bandeen-Roche, Karen; Mercer, Dione G.; Schwartz, Brian S.

2017-01-01

Importance Asthma is common and can be exacerbated by air pollution and stress. Unconventional natural gas development (UNGD) has community and environmental impacts. In Pennsylvania, development began in 2005 and by 2012, 6,253 wells were drilled. There are no prior studies of UNGD and objective respiratory outcomes. Objective To evaluate associations between UNGD and asthma exacerbations. Design A nested case-control study comparing asthma patients with exacerbations to asthma patients without exacerbations from 2005–12. Setting The Geisinger Clinic, which provides primary care services to over 400,000 patients in Pennsylvania. Participants Asthma patients aged 5–90 years (n = 35,508) were identified in electronic health records; those with exacerbations were frequency-matched on age, sex, and year of event to those without. Exposure(s) On the day before each patient’s index date (cases: date of event or medication order; controls: contact date), we estimated UNGD activity metrics for four phases (pad preparation, drilling, stimulation [“fracking”], and production) using distance from the patient’s home to the well, well characteristics, and the dates and durations of phases. Main Outcome(s) and Measure(s) We identified mild, moderate, and severe asthma exacerbations (new oral corticosteroid medication order, emergency department encounter, and hospitalization, respectively). Results We identified 20,749 mild, 1,870 moderate, and 4,782 severe asthma exacerbations, and frequency-matched these to 18,693, 9,350, and 14,104 control index dates, respectively. In three-level adjusted models, there was an association between the highest group of the activity metric for each UNGD phase compared to the lowest group for 11 out of 12 UNGD-outcome pairs (odds ratios [95% CI] ranged from 1.5 [1.2–1.7] for the association of the pad metric with severe exacerbations to 4.4 [3.8–5.2] for the association of the production metric with mild exacerbations). Six of the 12 UNGD-outcome associations had increasing odds ratios across quartiles. Our findings were robust to increasing levels of covariate control and in sensitivity analyses that included evaluation of some possible sources of unmeasured confounding. Conclusions and Relevance Residential UNGD activity metrics were statistically associated with increased odds of mild, moderate, and severe asthma exacerbations. Whether these associations are causal awaits further investigation, including more detailed exposure assessment. PMID:27428612

Hepatitis E virus as an etiology of acute exacerbation of previously unrecognized asymptomatic patients with hepatitis B virus-related chronic liver disease.

PubMed

Kumar, Manoj; Sharma, Barjesh C; Sarin, Shiv K

2008-06-01

Hepatitis E virus (HEV) has recently been implicated in episodes of acute decompensation in patients having underlying chronic liver disease (CLD) of varying etiology. However, HEV as a cause of acute exacerbation of previously asymptomatic and unrecognized hepatitis B virus (HBV)-infected patients is less well described. The aim of the present study was to investigate the etiology of acute exacerbation of previously asymptomatic and unrecognized HBV-infected patients and to evaluate the relative role of HEV. We also investigated the effect of superinfection on the clinical spectrum of underlying HBV infection. Forty-three patients presented with the following were retrospectively analyzed: (i) clinical features suggestive of acute hepatitis; (ii) with hepatitis B surface antigen (HBsAg) (+); (iii) IgM hepatitis B core antibody (IgM anti-HBc) (-); (iv) no previous history of liver disease; (v) no features suggestive of CLD at presentation; (vi) HBsAg remaining (+) for at least 12 months on follow up; and (vii) having a follow-up biopsy during the convalescent phase showing evidence of chronic hepatitis B. Of the 43 patients, 21 were hepatitis e antigen (HBeAg) (+) (Gr.1) and 22 HBeAg (-) (Gr.2) at presentation. In Gr.1, only two (9.5%) had superinfection (both with hepatitis A virus), whereas in Gr.2, 11 (50%) had superinfection (27.3% hepatitis E, 13.6% hepatitis A and 9.1% both) (P = 0.007). In Gr.1, the remaining 19 (90.5%) patients had spontaneous exacerbation (immune clearance with spontaneous seroconversion) whereas in Gr.2, the remaining 11 (50%) had spontaneous exacerbation (due to reactivation). Overall, HEV superinfection contributed to 20% of acute exacerbation episodes and, in particular, 36% of episodes in initially HBeAg (-) patients. Time to alanine aminotransferase normalization was longer in patients with superinfection (n = 13) as compared to spontaneous exacerbation (n = 30) (median [range] 36 [8-48]vs 16 [6-36] weeks, P = 0.001). During convalescence, there was no significant difference between histological activity index score (median [range] 8 [4-11]vs 8 [4-16] weeks, P = 0.629) and fibrosis scores (median [range] 3.5 [1-4]vs 2 [1-4] weeks, P = 0.099] on liver biopsy after recovery among patients with acute exacerbation due to superinfection and spontaneous exacerbation. Acute exacerbations in HBeAg (+) patients are most often due to spontaneous viral activation, while in HBeAg (-) patients, superinfection with non-B hepatitis viruses and spontaneous viral activation are equally common. HEV is an important cause of acute exacerbation in previously asymptomatic and unrecognized patients with HBV-related CLD.

Mitochondria mediate tumor necrosis factor-alpha/NF-kappaB signaling in skeletal muscle myotubes

NASA Technical Reports Server (NTRS)

Li, Y. P.; Atkins, C. M.; Sweatt, J. D.; Reid, M. B.; Hamilton, S. L. (Principal Investigator)

1999-01-01

Tumor necrosis factor-alpha (TNF-alpha) is implicated in muscle atrophy and weakness associated with a variety of chronic diseases. Recently, we reported that TNF-alpha directly induces muscle protein degradation in differentiated skeletal muscle myotubes, where it rapidly activates nuclear factor kappaB (NF-kappaB). We also have found that protein loss induced by TNF-alpha is NF-kappaB dependent. In the present study, we analyzed the signaling pathway by which TNF-alpha activates NF-kappaB in myotubes differentiated from C2C12 and rat primary myoblasts. We found that activation of NF-kappaB by TNF-alpha was blocked by rotenone or amytal, inhibitors of complex I of the mitochondrial respiratory chain. On the other hand, antimycin A, an inhibitor of complex III, enhanced TNF-alpha activation of NK-kappaB. These results suggest a key role of mitochondria-derived reactive oxygen species (ROS) in mediating NF-kappaB activation in muscle. In addition, we found that TNF-alpha stimulated protein kinase C (PKC) activity. However, other signal transduction mediators including ceramide, Ca2+, phospholipase A2 (PLA2), and nitric oxide (NO) do not appear to be involved in the activation of NF-kappaB.

Isoform-specific changes in the Na,K-ATPase of rat soleus muscle during acute hindlinb suspension

NASA Astrophysics Data System (ADS)

Krivoi, Igor; Heiny, Judith; Bouzinova, Elena; Matchkov, Vladimir; Kravtsova, Violetta; Petrov, Aleksey; Zefirov, Andrey; Vasiliev, Alexander

The largest pool of Na,K-ATPase (NKA) in a vertebrate's body is contained in the skeletal muscles where the alpha1 and alpha2 isoforms of NKA alpha subunit are expressed. The NKA is critically important for excitability, electrogenesis and contractility of skeletal muscle. Skeletal muscle use strongly regulates the content of NKA, and increased muscle activity differently regulates the alpha1 and alpha2 isoforms. However, whether skeletal muscle disuse affects NKA content and activity has not been investigated. This study examines for the first time the consequences of acute hindlinb suspension (HS) on the alpha1 and alpha2 NKA isozymes in rat soleus muscle. We subjected rats to HS for 6-12 hours and analyzed its effect on the resting membrane potential (RMP) in different sarcolemma regions of m.soleus fibers; the electrogenic transport activity, protein content and mRNA expression of the alpha1 and alpha2 NKA; the extracellular level of acetylcholine, and the plasma membrane localization of the alpha2 isozyme using confocal microscopy with cytochemistry. Our results show that 6 h HS specifically decreases the electrogenic activity of the NKA alpha2 isozyme and depolarizes m.soleus fibers. These effects are irreversible in the extrajunctional membrane region up to 12 h HS. The decreased alpha2 NKA activity is due to a decrease in enzyme activity rather than by altered protein content, mRNA expression, or localization in the sarcolemma. In addition, HS does not alter the alpha2 NKA electrogenic transport due to decreased extracellular acetylcholine level. However, adaptive mechanism(s) operate at the junctional membrane to restore alpha2 NKA electrogenic activities and the RMP after 12 h of HS. This mechanism operates specifically at the synaptic membrane region, presumably via increase in both alpha2 isozyme mRNA expression and protein content. This basic information on a protein as vital as the NKA is expected to advance our understanding of the cellular and molecular mechanisms responsible for microgravity-induced muscle atrophy. Supported by RFBR #13-04-00973; St. Petersburg State University research grants #1.50.1621.2013 and #1.38.231.2014; grant #MK-108.2014.4., the Novo Nordisk Foundation and N.I.H grant #1 R01 AR063710.

IGF-1-dependent subunit communication of the IGF-1 holoreceptor: Interactions between. alpha. beta. heterodimeric receptor halves

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

Wilden, P.A.; Treadway, J.L.; Morrison, B.D.

1989-12-12

Examination of {sup 125}I-IGF-1 affinity cross-linking and {beta}-subunit autophosphorylation has indicated that IGF-1 induces a covalent association of isolated {alpha}{beta} heterodimeric IGF-1 receptors into an {alpha}{sub 2}{beta}{sub 2} heterotetrameric state, in a similar manner to that observed for the insulin receptor. The formation of the {alpha}{sub 2}{beta}{sub 2} heterotetrameric IGF-1 receptor complex from the partially purified {alpha}{beta} heterodimers was time dependent with half-maximal formation in approximately 30 min at saturating IGF-1 concentrations. The IGF-1-dependent association of the partially purified {alpha}{beta} heterodimers into an {alpha}{sub 2}{beta}{sub 2} heterotetrameric state was specific for the IGF-1 receptors since IGF-1 was unable to stimulatemore » the protein kinase activity of the purified {alpha}{beta} heterodimeric insulin receptor complex. Incubation of the {alpha}{sub 2}{beta}{sub 2} heterotetrameric IGF-1 holoreceptor with the specific sulfhydryl agent iodoacetamide (IAN) did not alter {sup 125}I-IGF-1 binding or IGF-1 stimulation of protein kinase activity. However, IAN treatment of the {alpha}{beta} heterodimeric IGF-1 receptors inhibited the IGF-1 dependent covalent formation of the disulfide-linked {alpha}{sub 2}{beta}{sub 2} heterotetrameric complex. These data indicate that IGF-1 induces the covalent association of isolated {alpha}{beta} heterodimeric IGF-1 receptor complexes into a disulfide-linked {alpha}{sub 2}{beta}{sub 2} heterotetrameric state whereas Mn/MgATP induces a noncovalent association. Therefore, unlike the insulin receptor in which noncovalent association is sufficient for kinase activation, only the covalent assembly of the IGF-1 receptor {alpha}{beta} heterodimers into the {alpha}{sub 2}{beta}{sub 2} heterotetrameric holoreceptor complex is associated with ligand-stimulated protein kinase activation.« less

Akt mediates 17beta-estradiol and/or estrogen receptor-alpha inhibition of LPS-induced tumor necresis factor-alpha expression and myocardial cell apoptosis by suppressing the JNK1/2-NFkappaB pathway.

PubMed

Liu, Chung-Jung; Lo, Jeng-Fan; Kuo, Chia-Hua; Chu, Chun-Hsien; Chen, Li-Ming; Tsai, Fuu-Jen; Tsai, Chang-Hai; Tzang, Bor-Show; Kuo, Wei-Wen; Huang, Chih-Yang

2009-09-01

Evidence shows that women have lower tumour necrosis factor-alpha (TNF-alpha) levels and lower incidences of heart dysfunction and sepsis-related morbidity and mortality. To identify the cardioprotective effects and precise cellular/molecular mechanisms behind estrogen and estrogen receptors (ERs), we investigated the effects of 17beta-estradiol (E(2)) and estrogen receptor alpha (ERalpha) on LPS-induced apoptosis by analyzing the activation of survival and death signalling pathways in doxycycline (Dox)-inducible Tet-On/ERalpha H9c2 myocardial cells and ERalpha-transfected primary cardiomyocytes overexpressing ERalpha. We found that LPS challenge activated JNK1/2, and then induced IkappaB degradation, NFkappaB activation, TNF-alpha up-regulation and subsequent myocardial apoptotic responses. In addition, treatments involving E(2), membrane-impermeable BSA-E(2) and/or Dox, which induces ERalpha overexpression, significantly inhibited LPS-induced apoptosis by suppressing LPS-up-regulated JNK1/2 activity, IkappaB degradation, NFkappaB activation and pro-apoptotic proteins (e.g. TNF-alpha, active caspases-8, t-Bid, Bax, released cytochrome c, active caspase-9, active caspase-3) in myocardial cells. However, the cardioprotective properties of E(2), BSA-E(2) and ERalpha overexpression to inhibit LPS-induced apoptosis and promote cell survival were attenuated by applying LY294002 (PI3K inhibitor) and PI3K siRNA. These findings suggest that E(2), BSA-E(2) and ERalpha expression exert their cardioprotective effects by inhibiting JNK1/2-mediated LPS-induced TNF-alpha expression and cardiomyocyte apoptosis through activation of Akt.

Curcumin inhibits interferon-{alpha} induced NF-{kappa}B and COX-2 in human A549 non-small cell lung cancer cells

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

Lee, Jeeyun; Im, Young-Hyuck; Jung, Hae Hyun

2005-08-26

The A549 cells, non-small cell lung cancer cell line from human, were resistant to interferon (IFN)-{alpha} treatment. The IFN-{alpha}-treated A549 cells showed increase in protein expression levels of NF-{kappa}B and COX-2. IFN-{alpha} induced NF-{kappa}B binding activity within 30 min and this increased binding activity was markedly suppressed with inclusion of curcumin. Curcumin also inhibited IFN-{alpha}-induced COX-2 expression in A549 cells. Within 10 min, IFN-{alpha} rapidly induced the binding activity of a {gamma}-{sup 32}P-labeled consensus GAS oligonucleotide probe, which was profoundly reversed by curcumin. Taken together, IFN-{alpha}-induced activations of NF-{kappa}B and COX-2 were inhibited by the addition of curcumin in A549more » cells.« less

Host response to Staphylococcus aureus cytotoxins in children with cystic fibrosis.

PubMed

Chadha, Ashley D; Thomsen, Isaac P; Jimenez-Truque, Natalia; Soper, Nicole R; Jones, Lauren S; Sokolow, Andrew G; Torres, Victor J; Creech, C Buddy

2016-09-01

Staphylococcus aureus is one of the earliest bacterial pathogens to colonize the lungs of children with cystic fibrosis and is an important contributor to pulmonary exacerbations. The adaptive host response to S. aureus in cystic fibrosis remains inadequately defined and has important implications for pathogenesis and potential interventions. The objectives of this study were to determine the functional antibody response to select staphylococcal exotoxins (LukAB, alpha-hemolysin, and PVL) in children with cystic fibrosis and to evaluate the relationship of this response with pulmonary exacerbations. Fifty children with cystic fibrosis were enrolled and followed prospectively for 12months. Clinical characteristics and serologic profiles were assessed at routine visits and during pulmonary exacerbations, and functional antibody assessments were performed to measure neutralization of LukAB-mediated cytotoxicity. For each antigen, geometric mean titers were significantly higher if S. aureus was detected at the time of exacerbation. For LukAB, geometric mean titers were significantly higher at exacerbation follow-up compared to titers during the exacerbation, consistent with expression during human disease, and the humoral response capably neutralized LukAB-mediated cytotoxicity. Moreover, the presence of a positive S. aureus culture during a pulmonary exacerbation was associated with 31-fold higher odds of having a LukA titer ≥1:160, suggesting potential diagnostic capability of this assay. The leukotoxin LukAB is expressed by S. aureus and recognized by the human adaptive immune response in the setting of pulmonary infection in cystic fibrosis. Anti-LukAB antibodies were not only predictive of positive staphylococcal culture during exacerbation, but also functional in the neutralization of this toxin. Copyright © 2016 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Alpha-synuclein: relating metals to structure, function and inhibition.

PubMed

McDowall, J S; Brown, D R

2016-04-01

Alpha-synuclein has long been studied due to its involvement in the progression of Parkinson's disease (PD), a common neurodegenerative disorder, although a consensus on the exact function of this protein is elusive. This protein shows remarkable structural plasticity and this property is important for both correct cellular function and pathological progression of PD. Formation of intracellular oligomeric species within the substantia nigra correlates with disease progression and it has been proposed that formation of a partially folded intermediate is key to the initiation of the fibrillisation process. Many factors can influence changes in the structure of alpha-synuclein such as disease mutations and interaction with metals and neurotransmitters. High concentrations of both dopamine and metals are present in the substantia nigra making this an ideal location for both the structural alteration of alpha-synuclein and the production of toxic oxygen species. The recent proposal that alpha-synuclein is a ferrireductase is important as it can possibly catalyse the formation of such reactive species and as a result exacerbate neurodegeneration.

Characterization and localization of progesterone 5 alpha-reductase from cell cultures of foxglove (Digitalis lanata EHRH).

PubMed Central

Wendroth, S; Seitz, H U

1990-01-01

Progesterone 5 alpha-reductase, which catalyses the reduction of progesterone to 5 alpha-pregnane-3,20-dione, was isolated and characterized from cell cultures of Digitalis lanata (foxglove). Optimum enzyme activity was observed at pH 7.0, and the enzyme had an apparent Km value of 30 microM for its substrate progesterone. The enzyme needs NADPH as reductant, which could not be replaced by NADH. For NADPH, the apparent Km value is 130 microM. The optimum temperature was 40 degrees C; at temperatures below 45 degrees C, the product 5 alpha-pregnane-3,20-dione was reduced by a second reaction to 5 alpha-pregnan-3 beta-ol-20-one. Progesterone 5 alpha-reductase activity was not dependent on bivalent cations. In the presence of EDTA, 0.1 mM-Mn2+ had no influence on enzyme activity, whereas 0.1 mM-Ca2+, -Co2+ and -Zn2+ decreased progesterone 5 alpha-reductase activity. Only 0.1 mM-Mg2+ was slightly stimulatory. EDTA and thiol reagents such as dithiothreitol stimulate progesterone 5 alpha-reductase activity. By means of linear sucrose gradient fractionation of the cellular membranes, progesterone 5 alpha-reductase was found to be located in the endoplasmic reticulum. PMID:2106876

The damaging effect of UV-C irradiation on lens alpha-crystallin.

PubMed

Fujii, Noriko; Uchida, Hiroki; Saito, Takeshi

2004-11-02

To evaluate the effect of UV-C irradiation on the structural properties of alpha-crystallin and its chaperone activity. alpha- and betaL-crystallins were isolated from bovine lenses using gel chromatography. The purified alpha-crystallin was subjected to UV-C irradiation (254 nm; 1, 2, 5, 10, 20, 50 J/cm2). We measured the tryptophan fluorescence, circular dichroism (CD) spectroscopy in the far UV, and the chaperone activity of both irradiated and non-irradiated alpha-crystallin. The tryptophan fluorescence of alpha-crystallin decreased, whereas the N-formylkynurenine fluorescence increased markedly with increasing doses of UV-C irradiation. Both the oxidation of Met1 and the racemization of Asp151 of alphaA-crystallin increased at a dose of 1-2 J/cm2 and then gradually decreased. The CD spectrum showed that the secondary structure of alpha-crystallin altered with increasing radiation dose, and almost all of the beta-sheet structure was lost at doses above 50 J/cm2. The chaperone activity of alpha-crystallin irradiated with doses under 5 J/cm2 remained intact. However, it was reduced to only 40% after irradiation at 10 J/cm2. Our study suggests that photo-oxidation of tryptophan residues in alpha-crystallin may be one of the events that affects the three-dimensional packing array and chaperone activity of this lens protein.

Nonsteroidal anti-inflammatory drugs increase TNF production in rheumatoid synovial membrane cultures and whole blood.

PubMed

Page, Theresa H; Turner, Jeremy J O; Brown, Anthony C; Timms, Emma M; Inglis, Julia J; Brennan, Fionula M; Foxwell, Brian M J; Ray, Keith P; Feldmann, Marc

2010-09-15

Nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit cyclooxygenase activity and hence PG production. However, the ability of NSAIDs to ameliorate pain and tenderness does not prevent disease progression in rheumatoid arthritis, a disease whose pathogenesis is linked to the presence of proinflammatory cytokines, such as TNF-alpha. To understand this observation, we have examined the effect of NSAIDs on the production of clinically validated proinflammatory cytokines. We show that a variety of NSAIDs superinduce production of TNF from human peripheral blood monocytes and rheumatoid synovial membrane cultures. A randomized, double-blinded, crossover, placebo-controlled trial in healthy human volunteers also revealed that the NSAID drug celecoxib increased LPS-induced TNF production in whole blood. NSAID-mediated increases in TNF are reversed by either the addition of exogenous PGE(2) or by a PGE(2) EP2 receptor agonist, revealing that PGE(2) signaling via its EP2 receptor provides a valuable mechanism for controlling excess TNF production. Thus, by reducing the level of PGE(2), NSAIDs can increase TNF production and may exacerbate the proinflammatory environment both within the rheumatoid arthritis joint and the systemic environment.

Lipid peroxidation products do not activate hepatic stellate cells.

PubMed

Fang, Hsun-Lang; Lin, Wen-Chuan

2008-11-20

Lipid peroxidation (LPO) is known to be associated with liver fibrosis in chronic liver injury. However, direct effects of the products of LPO on liver fibrogenesis are still not clear. In this study, we examined the LPO products, such as malondiladehyde (MDA), 8-iso-prostaglandin F(2alpha) (8-iso-PGF(2alpha)), and 15-keto-13,14-dihydro-PGF(2alpha) (15-keto-PGF(2alpha)), on the activation of hepatic stellate cells (HSCs) in vivo and in vitro. Carbon tetrachloride (CCl(4)) was given orally to rats twice a week for 8 weeks. Corn oil was given daily to rats for 8 weeks. CCl(4) induced both free-radical-medicated and cyclooxygenase-2-dependent LPO. Free radical-medicated LPO showed an increase with corn oil treatment, whereas no effect was reflected on COX-2-dependent LPO. CCl(4) induced liver fibrosis in rats, but no liver fibrosis was observed in rats treated with corn oil. In vitro studies demonstrated that MDA, 8-iso-PGF(2alpha) and 15-keto-PGF(2alpha), did not activate HSCs, which were preactivated or not preactivated by TGF-beta1. Our results clearly indicate that LPO products, such as MDA, 8-iso-PGF(2alpha) and 15-keto-PGF(2alpha), cannot directly activate HSCs.

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

Molina-Molina, Jose-Manuel; INSERM, U896, Montpellier, F-34298; Universite Montpellier1, Montpellier, F-34298

Benzophenone (BP) derivatives, BP1 (2,4-dihydroxybenzophenone), BP2 (2,2',4,4'-tetrahydroxybenzophenone), BP3 (2-hydroxy-4-methoxybenzophenone), and THB (2,4,4'-trihydroxybenzophenone) are UV-absorbing chemicals widely used in pharmaceutical, cosmetics, and industrial applications, such as topical sunscreens in lotions and hair sprays to protect skin and hair from UV irradiation. Studies on their endocrine disrupting properties have mostly focused on their interaction with human estrogen receptor alpha (hER{alpha}), and there has been no comprehensive analysis of their potency in a system allowing comparison between hER{alpha} and hER{beta} activities. The objective of this study was to provide a comprehensive ER activation profile of BP derivatives using ER from human and fishmore » origin in a battery of in vitro tests, i.e., competitive binding, reporter gene based assays, vitellogenin (Vtg) induction in isolated rainbow trout hepatocytes, and proliferation based assays. The ability to induce human androgen receptor (hAR)-mediated reporter gene expression was also examined. All BP derivatives tested except BP3 were full hER{alpha} and hER{beta} agonists (BP2 > THB > BP1) and displayed a stronger activation of hER{beta} compared with hER{alpha}, the opposite effect to that of estradiol (E{sub 2}). Unlike E{sub 2}, BPs were more active in rainbow trout ER{alpha} (rtER{alpha}) than in hER{alpha} assay. All four BP derivatives showed anti-androgenic activity (THB > BP2 > BP1 > BP3). Overall, the observed anti-androgenic potencies of BP derivatives, together with their proposed greater effect on ER{beta} versus ER{alpha} activation, support further investigation of their role as endocrine disrupters in humans and wildlife.« less

Gq protein mediates UVB-induced cyclooxygenase-2 expression by stimulating HB-EGF secretion from HaCaT human keratinocytes

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

Seo, MiRan; Juhnn, Yong-Sung, E-mail: juhnn@snu.ac.kr

Ultraviolet (UV) radiation induces cyclooxygenase-2 expression to produce cellular responses including aging and carcinogenesis in skin. We hypothesised that heterotrimeric G proteins mediate UV-induced COX-2 expression by stimulating secretion of soluble HB-EGF (sHB-EGF). In this study, we aimed to elucidate the role and underlying mechanism of the {alpha} subunit of Gq protein (G{alpha}q) in UVB-induced HB-EGF secretion and COX-2 induction. We found that expression of constitutively active G{alpha}q (G{alpha}qQL) augmented UVB-induced HB-EGF secretion, which was abolished by knockdown of G{alpha}q with shRNA in HaCaT human keratinocytes. G{alpha}q was found to mediate the UVB-induced HB-EGF secretion by sequential activation of phospholipasemore » C (PLC), protein kinase C{delta} (PKC{delta}), and matrix metaloprotease-2 (MMP-2). Moreover, G{alpha}qQL mediated UVB-induced COX-2 expression in an HB-EGF-, EGFR-, and p38-dependent manner. From these results, we concluded that G{alpha}q mediates UV-induced COX-2 expression through activation of EGFR by HB-EGF, of which ectodomain shedding was stimulated through sequential activation of PLC, PKC{delta} and MMP-2 in HaCaT cells.« less

Rational design, synthesis, biologic evaluation, and structure-activity relationship studies of novel 1-indanone alpha(1)-adrenoceptor antagonists.

PubMed

Li, Minyong; Xia, Lin

2007-11-01

In the present report, a novel series of 1-indanone alpha(1)-adrenoceptor antagonists were designed and synthesized based on 3D-pharmacophore model. Their in vitro alpha(1)-adrenoceptor antagonistic assay showed that three compounds (2a, 2m, and 2o) had similar or improved alpha(1)-adrenoceptor antagonistic activities relative to the positive control prazosin. Based on these results, a three-dimensional quantitative structure-activity relationship study was performed using a Self-Organizing Molecular Field Analysis method to provide insight for the future development of alpha(1)-adrenoceptor antagonists.

Activation of c-Raf-1 kinase signal transduction pathway in alpha(7) integrin-deficient mice.

PubMed

Saher, G; Hildt, E

1999-09-24

Integrin alpha(7)-deficient mice develop a novel form of muscular dystrophy. Here we report that deficiency of alpha(7) integrin causes an activation of the c-Raf-1/mitogen-activated protein (MAP) 2 kinase signal transduction pathway in muscle cells. The observed activation of c-Raf-1/MAP2 kinases is a specific effect, because the alpha(7) integrin deficiency does not cause unspecific stress as determined by measurement of the Hsp72/73 level and activity of the JNK2 kinase. Because an increased level of activated FAK was found in muscle of alpha(7) integrin-deficient mice, the activation of c-Raf-1 kinase is triggered most likely by an integrin-dependent pathway. In accordance with this, in the integrin alpha(7)-deficient mice, part of the integrin beta(1D) variant in muscle is replaced by the beta(1A) variant, which permits the FAK activation. A recent report describes that integrin activity can be down-modulated by the c-Raf-1/MAP2 kinase pathway. Specific activation of the c-Raf-1/MAP2 kinases by cell-permeable peptides in skeletal muscle of rabbits causes degeneration of muscle fibers. Therefore, we conclude that in alpha(7) integrin-deficient mice, the continuous activation of c-Raf-1 kinase causes a permanent reduction of integrin activity diminishing integrin-dependent cell-matrix interactions and thereby contributing to the development of the dystrophic phenotype.

Serial immune markers do not correlate with clinical exacerbations in pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections.

PubMed

Singer, Harvey S; Gause, Colin; Morris, Christina; Lopez, Pablo

2008-06-01

Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections is hypothesized to be a poststreptococcal autoimmune disorder. If clinical exacerbations are triggered by a streptococcal infection that activates cross-reacting antibodies against neuronal tissue or alters the production of cytokines, then a longitudinal analysis would be expected to identify a correlation between clinical symptoms and a change in autoimmune markers. Serial serum samples were available on 12 children with pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections participating in a prospective blinded study: 2 samples before an exacerbation point, 1 during the clinical exacerbation, and 2 after the exacerbation. Six subjects had a well-defined clinical exacerbation in association with a documented streptococcal infection, and 6 had a clinical exacerbation without an associated streptococcal infection. All of the serum samples were assayed for antibodies against human postmortem caudate, putamen, and prefrontal cortex; commercially prepared antigens; and complex sugars. Cytokines were measured by 2 different methodologies. No correlation was identified between clinical exacerbations and autoimmune markers, including: enzyme-linked immunosorbent assay measures of antineuronal antibodies; Western immunoblotting with emphasis on brain region proteins located at 40, 45, and 60 kDa or their corresponding identified antigens; competitive inhibition enzyme-linked immunosorbent assay to evaluate lysoganglioside G(M1) antibodies; and measures of inflammatory cytokines. No differences were identified between individuals with pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections with or without exacerbations triggered by streptococcal infections. The failure of immune markers to correlate with clinical exacerbations in children with pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections raises serious concerns about the viability of autoimmunity as a pathophysiological mechanism in this disorder.

Adenylyl cyclase and G-proteins in Phytomonas.

PubMed

Farber, M D; Montagna, A E; Paveto, C; Dollet, M; Sanchex-Moreno, M; Osuna, A; Torres, H N; Flawia, M M

1995-01-01

Phytomonas sp. membranes have an adenylyl cyclase activity which is greater in the presence of Mn2+ than with Mg2+. The Mg2+ and Mn2+ activity ratio varies from one membrane preparation to another, suggesting that the adenylyl cyclase has a variable activation state. A[35S]GTP-gamma-S-binding activity with a Kd of 171 nM was detected in Phytomonas membranes. Incubation of these membranes with activated cholera or pertussis toxin and [adenylate 23P]NAD+ led to incorporation of radioactivity into bands of about 40-44 kDa. Crude membranes were electrophoresed on SDS-polyacrylamide gels and analyzed, by Western blotting, with the 9188 anti-alpha[s] antibody and the AS/7 antibody (anti-alpha[i], anti-alpha[i1], and anti-alpha[i2]. These procedures resulted in the identification of polypeptides of approximately 40-44 kDa. Phytomonas adenylyl cyclase could be activated by treatment of membrane preparations with cholera toxin, in the presence of NAD+, while similar treatment with pertussis toxin did not affect this enzyme activity. These studies indicate that in Phytomonas, adenylyl cyclase activity is coupled to an unknown receptor entity through G alpha[s] proteins.

Gamma motor neurons survive and exacerbate alpha motor neuron degeneration in ALS.

PubMed

Lalancette-Hebert, Melanie; Sharma, Aarti; Lyashchenko, Alexander K; Shneider, Neil A

2016-12-20

The molecular and cellular basis of selective motor neuron (MN) vulnerability in amyotrophic lateral sclerosis (ALS) is not known. In genetically distinct mouse models of familial ALS expressing mutant superoxide dismutase-1 (SOD1), TAR DNA-binding protein 43 (TDP-43), and fused in sarcoma (FUS), we demonstrate selective degeneration of alpha MNs (α-MNs) and complete sparing of gamma MNs (γ-MNs), which selectively innervate muscle spindles. Resistant γ-MNs are distinct from vulnerable α-MNs in that they lack synaptic contacts from primary afferent (I A ) fibers. Elimination of these synapses protects α-MNs in the SOD1 mutant, implicating this excitatory input in MN degeneration. Moreover, reduced I A activation by targeted reduction of γ-MNs in SOD1 G93A mutants delays symptom onset and prolongs lifespan, demonstrating a pathogenic role of surviving γ-MNs in ALS. This study establishes the resistance of γ-MNs as a general feature of ALS mouse models and demonstrates that synaptic excitation of MNs within a complex circuit is an important determinant of relative vulnerability in ALS.

Gamma motor neurons survive and exacerbate alpha motor neuron degeneration in ALS

PubMed Central

Lalancette-Hebert, Melanie; Sharma, Aarti; Lyashchenko, Alexander K.; Shneider, Neil A.

2016-01-01

The molecular and cellular basis of selective motor neuron (MN) vulnerability in amyotrophic lateral sclerosis (ALS) is not known. In genetically distinct mouse models of familial ALS expressing mutant superoxide dismutase-1 (SOD1), TAR DNA-binding protein 43 (TDP-43), and fused in sarcoma (FUS), we demonstrate selective degeneration of alpha MNs (α-MNs) and complete sparing of gamma MNs (γ-MNs), which selectively innervate muscle spindles. Resistant γ-MNs are distinct from vulnerable α-MNs in that they lack synaptic contacts from primary afferent (IA) fibers. Elimination of these synapses protects α-MNs in the SOD1 mutant, implicating this excitatory input in MN degeneration. Moreover, reduced IA activation by targeted reduction of γ-MNs in SOD1G93A mutants delays symptom onset and prolongs lifespan, demonstrating a pathogenic role of surviving γ-MNs in ALS. This study establishes the resistance of γ-MNs as a general feature of ALS mouse models and demonstrates that synaptic excitation of MNs within a complex circuit is an important determinant of relative vulnerability in ALS. PMID:27930290

Adiponectin promotes hyaluronan synthesis along with increases in hyaluronan synthase 2 transcripts through an AMP-activated protein kinase/peroxisome proliferator-activated receptor-{alpha}-dependent pathway in human dermal fibroblasts

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

Yamane, Takumi; Kobayashi-Hattori, Kazuo; Oishi, Yuichi, E-mail: y3oishi@nodai.ac.jp

2011-11-18

Highlights: Black-Right-Pointing-Pointer Adiponectin promotes hyaluronan synthesis along with an increase in HAS2 transcripts. Black-Right-Pointing-Pointer Adiponectin also increases the phosphorylation of AMPK. Black-Right-Pointing-Pointer A pharmacological activator of AMPK increases mRNA levels of PPAR{alpha} and HAS2. Black-Right-Pointing-Pointer Adiponectin-induced HAS2 mRNA expression is blocked by a PPAR{alpha} antagonist. Black-Right-Pointing-Pointer Adiponectin promotes hyaluronan synthesis via an AMPK/PPAR{alpha}-dependent pathway. -- Abstract: Although adipocytokines affect the functions of skin, little information is available on the effect of adiponectin on the skin. In this study, we investigated the effect of adiponectin on hyaluronan synthesis and its regulatory mechanisms in human dermal fibroblasts. Adiponectin promoted hyaluronan synthesis alongmore » with an increase in the mRNA levels of hyaluronan synthase 2 (HAS2), which plays a primary role in hyaluronan synthesis. Adiponectin also increased the phosphorylation of AMP-activated protein kinase (AMPK). A pharmacological activator of AMPK, 5-aminoimidazole-4-carboxamide-1{beta}-ribofuranoside (AICAR), increased mRNA levels of peroxisome proliferator-activated receptor-{alpha} (PPAR{alpha}), which enhances the expression of HAS2 mRNA. In addition, AICAR increased the mRNA levels of HAS2. Adiponectin-induced HAS2 mRNA expression was blocked by GW6471, a PPAR{alpha} antagonist, in a concentration-dependent manner. These results show that adiponectin promotes hyaluronan synthesis along with increases in HAS2 transcripts through an AMPK/PPAR{alpha}-dependent pathway in human dermal fibroblasts. Thus, our study suggests that adiponectin may be beneficial for retaining moisture in the skin, anti-inflammatory activity, and the treatment of a variety of cutaneous diseases.« less

Prostaglandin F(2alpha) stimulates tyrosine phosphorylation of phospholipase C-gamma1.

PubMed

Husain, Shahid; Jafri, Farahdiba

2002-10-11

In this study, we investigated the ability of prostaglandin F(2alpha) (PGF(2alpha)) to induce tyrosine phosphorylation of phospholipase C-gamma1 (PLC-gamma1) in cat iris sphincter smooth muscle (CISM) cells. PGF(2alpha)(1 microM) stimulated PLC-gamma1 tyrosine phosphorylation in a time- and dose-dependent manner with a maximum increase of 3-fold at 0.5min. The protein tyrosine kinase inhibitors, genistein, and tyrphostin A-25, blocked the stimulatory effects of PGF(2alpha), suggesting involvement of protein tyrosine kinase activity in the physiological actions of the PGF(2alpha). Furthermore, PGF(2alpha)-induced p42/p44 MAP kinase activation was also completely blocked by protein tyrosine kinase inhibitors. In summary, these findings show that PGF(2alpha) stimulates tyrosine phosphorylation of PLC-gamma1 in CISM cells and indicate that PGF(2alpha)-stimulated tyrosine phosphorylation is responsible for an early signal transduction event.

TNF{alpha} acting on TNFR1 promotes breast cancer growth via p42/P44 MAPK, JNK, Akt and NF-{kappa}B-dependent pathways

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

Rivas, Martin A.; Carnevale, Romina P.; Proietti, Cecilia J.

2008-02-01

Tumor necrosis factor {alpha} (TNF{alpha}) enhances proliferation of chemically-induced mammary tumors and of T47D human cell line through not fully understood pathways. Here, we explored the intracellular signaling pathways triggered by TNF{alpha}, the participation of TNF{alpha} receptor (TNFR) 1 and TNFR2 and the molecular mechanism leading to breast cancer growth. We demonstrate that TNF{alpha} induced proliferation of C4HD murine mammary tumor cells and of T47D cells through the activation of p42/p44 MAPK, JNK, PI3-K/Akt pathways and nuclear factor-kappaB (NF-{kappa}B) transcriptional activation. A TNF{alpha}-specific mutein selectively binding to TNFR1 induced p42/p44 MAPK, JNK, Akt activation, NF-{kappa}B transcriptional activation and cell proliferation,more » just like wild-type TNF{alpha}, while a mutein selective for TNFR2 induced only p42/p44 MAPK activation. Interestingly, blockage of TNFR1 or TNFR2 with specific antibodies was enough to impair TNF{alpha} signaling and biological effect. Moreover, in vivo TNF{alpha} administration supported C4HD tumor growth. We also demonstrated, for the first time, that injection of a selective inhibitor of NF-{kappa}B activity, Bay 11-7082, resulted in regression of TNF{alpha}-promoted tumor. Bay 11-7082 blocked TNF{alpha} capacity to induce cell proliferation and up-regulation of cyclin D1 and of Bcl-x{sub L}in vivo and in vitro. Our results reveal evidence for TNF{alpha} as a breast tumor promoter, and provide novel data for a future therapeutic approach using TNF{alpha} antagonists and NF-{kappa}B pharmacological inhibitors in established breast cancer treatment.« less

Defects in maintenance of mitochondrial DNA are associated with intramitochondrial nucleotide imbalances.

PubMed

Ashley, Neil; Adams, Susan; Slama, Abdelhamid; Zeviani, Massimo; Suomalainen, Anu; Andreu, Antonio L; Naviaux, Robert K; Poulton, Joanna

2007-06-15

Defects in mtDNA maintenance range from fatal multisystem childhood diseases, such as Alpers syndrome, to milder diseases in adults, including mtDNA depletion syndromes (MDS) and familial progressive external ophthalmoplegia (AdPEO). Most are associated with defects in genes involved in mitochondrial deoxynucleotide metabolism or utilization, such as mutations in thymidine kinase 2 (TK2) as well as the mtDNA replicative helicase, Twinkle and gamma polymerase (POLG). We have developed an in vitro system to measure incorporation of radiolabelled dNTPs into mitochondria of saponin permeabilized cells. We used this to compare the rates of mtDNA synthesis in cells from 12 patients with diseases of mtDNA maintenance. We observed reduced incorporation of exogenous alpha (32)P-dTTP in fibroblasts from a patient with Alpers syndrome associated with the A467T substitution in POLG, a patient with dGK mutations, and a patient with mtDNA depletion of unknown origin compared to controls. However, incorporation of alpha (32)P-dTTP relative to either cell doubling time or alpha (32)P-dCTP incorporation was increased in patients with thymidine kinase deficiency or PEO as the result of TWINKLE mutations compared with controls. The specific activity of newly synthesized mtDNA depends on the size of the endogenous pool diluting the exogenous labelled nucleotide. Our result is consistent with a deficiency in the intramitochondrial pool of dTTP relative to dCTP in cells from patients with TK2 deficiency and TWINKLE mutations. Such DNA precursor asymmetry could cause pausing of the replication complex and hence exacerbate the propensity for age-related mtDNA mutations. Because deviations from the normal concentrations of dNTPs are known to be mutagenic, we suggest that intramitochondrial nucleotide imbalance could underlie the multiple mtDNA mutations observed in these patients.

The convulsive and electroencephalographic changes produced by nonpeptidic delta-opioid agonists in rats: comparison with pentylenetetrazol.

PubMed

Jutkiewicz, Emily M; Baladi, Michelle G; Folk, John E; Rice, Kenner C; Woods, James H

2006-06-01

delta-Opioid agonists produce convulsions and antidepressant-like effects in rats. It has been suggested that the antidepressant-like effects are produced through a convulsant mechanism of action either through overt convulsions or nonconvulsive seizures. This study evaluated the convulsive and seizurogenic effects of nonpeptidic delta-opioid agonists at doses that previously were reported to produce antidepressant-like effects. In addition, delta-opioid agonist-induced electroencephalographic (EEG) and behavioral changes were compared with those produced by the chemical convulsant pentylenetetrazol (PTZ). For these studies, EEG changes were recorded using a telemetry system before and after injections of the delta-opioid agonists [(+)-4-[(alphaR)-alpha-[(2S,5R)-2,5-dimethyl-4-(2-propenyl)-1-piperazinyl]-(3-methoxyphenyl)methyl]-N,N-diethylbenz (SNC80) and [(+)-4-[alpha(R)-alpha-[(2S,5R)-2,5-dimethyl-4-(2-propenyl)-1-piperazinyl]-(3-hydroxyphenyl)methyl]-N,N-diethylbenzamide [(+)-BW373U86]. Acute administration of nonpeptidic delta-opioid agonists produced bilateral ictal and paroxysmal spike and/or sharp wave discharges. delta-Opioid agonists produced brief changes in EEG recordings, and tolerance rapidly developed to these effects; however, PTZ produced longer-lasting EEG changes that were exacerbated after repeated administration. Studies with antiepileptic drugs demonstrated that compounds used to treat absence epilepsy blocked the convulsive effects of nonpeptidic delta-opioid agonists. Overall, these data suggest that delta-opioid agonist-induced EEG changes are not required for the antidepressant-like effects of these compounds and that neural circuitry involved in absence epilepsy may be related to delta-opioid agonist-induced convulsions. In terms of therapeutic development, these data suggest that it may be possible to develop delta-opioid agonists devoid of convulsive properties.

TNF-alpha increases ubiquitin-conjugating activity in skeletal muscle by up-regulating UbcH2/E220k

NASA Technical Reports Server (NTRS)

Li, Yi-Ping; Lecker, Stewart H.; Chen, Yuling; Waddell, Ian D.; Goldberg, Alfred L.; Reid, Michael B.

2003-01-01

In some inflammatory diseases, TNF-alpha is thought to stimulate muscle catabolism via an NF-kappaB-dependent process that increases ubiquitin conjugation to muscle proteins. The transcriptional mechanism of this response has not been determined. Here we studied the potential role of UbcH2, a ubiquitin carrier protein and homologue of murine E220k. We find that UbcH2 is constitutively expressed by human skeletal and cardiac muscles, murine limb muscle, and cultured myotubes. TNF-alpha stimulates UbcH2 expression in mouse limb muscles in vivo and in cultured myotubes. The UbcH2 promoter region contains a functional NF-kappaB binding site; NF-kappaB binding to this sequence is increased by TNF-alpha stimulation. A dominant negative inhibitor of NF-kappaB activation blocks both UbcH2 up-regulation and the increase in ubiquitin-conjugating activity stimulated by TNF-alpha. In extracts from TNF-alpha-treated myotubes, ubiquitin-conjugating activity is limited by UbcH2 availability; activity is inhibited by an antiserum to UbcH2 or a dominant negative mutant of UbcH2 and is enhanced by wild-type UbcH2. Thus, UbcH2 up-regulation is a novel response to TNF-alpha/NF-kappaB signaling in skeletal muscle that appears to be essential for the increased ubiquitin conjugation induced by this cytokine.

Activation of proteinase 3 contributes to Non-alcoholic Fatty Liver Disease (NAFLD) and insulin resistance.

PubMed

Toonen, Erik J M; Mirea, Andreea-Manuela; Tack, Cees J; Stienstra, Rinke; Ballak, Dov B; van Diepen, Janna A; Hijmans, Anneke; Chavakis, Triantafyllos; Dokter, Wim H; Pham, Christine T N; Netea, Mihai G; Dinarello, Charles A; Joosten, Leo A B

2016-05-24

Activation of inflammatory pathways is known to accompany development of obesity-induced non-alcoholic fatty liver disease (NAFLD), insulin resistance and type 2 diabetes. In addition to caspase-1, the neutrophil serine proteases proteinase 3, neutrophil elastase and cathepsin G are able to process the inactive pro-inflammatory mediators IL-1β and IL-18 to their bioactive forms, thereby regulating inflammatory responses. In the present study, we investigated whether proteinase 3 is involved in obesity-induced development of insulin resistance and NAFLD. We investigated the development of NAFLD and insulin resistance in mice deficient for neutrophil elastase/proteinase 3 and neutrophil elastase/cathepsin G and in wild-type mice treated with the neutrophil serine proteinase inhibitor human alpha-1 antitrypsin. Expression profiling of metabolically relevant tissues obtained from insulin resistant mice showed that expression of proteinase 3 was specifically upregulated in the liver, whereas neutrophil elastase, cathepsin G and caspase-1 were not. Neutrophil elastase/proteinase 3 deficient mice showed strongly reduced levels of lipids in the liver after fed a high fat diet. Moreover, these mice were resistant to high fat diet-induced weight gain, inflammation and insulin resistance. Injection of proteinase 3 exacerbated insulin resistance in caspase-1(-/-) mice, indicating that proteinase 3 acts independently of caspase-1. Treatment with alpha-1 antitrypsin during the last 10 days of a 16 week high fat diet reduced hepatic lipid content and decreased fasting glucose levels. We conclude that proteinase 3 is involved in NAFLD and insulin resistance and that inhibition of proteinase 3 may have therapeutic potential.

Loss of Angiotensin-Converting Enzyme 2 Exacerbates Diabetic Retinopathy by Promoting Bone Marrow Dysfunction.

PubMed

Duan, Yaqian; Beli, Eleni; Li Calzi, Sergio; Quigley, Judith L; Miller, Rehae C; Moldovan, Leni; Feng, Dongni; Salazar, Tatiana E; Hazra, Sugata; Al-Sabah, Jude; Chalam, Kakarla V; Le Phuong Trinh, Thao; Meroueh, Marya; Markel, Troy A; Murray, Matthew C; Vyas, Ruchi J; Boulton, Michael E; Parsons-Wingerter, Patricia; Oudit, Gavin Y; Obukhov, Alexander G; Grant, Maria B

2018-05-15

Angiotensin-converting enzyme 2 (ACE2) is the primary enzyme of the vasoprotective axis of the renin angiotensin system (RAS). We tested the hypothesis that loss of ACE2 would exacerbate diabetic retinopathy by promoting bone marrow dysfunction. ACE2 -/y were crossed with Akita mice, a model of type 1 diabetes. When comparing the bone marrow of the ACE2 -/y -Akita mice to that of Akita mice, we observed a reduction of both short-term and long-term repopulating hematopoietic stem cells, a shift of hematopoiesis towards myelopoiesis, and an impairment of lineage - c-kit + hematopoietic stem/progenitor cell (HS/PC) migration and proliferation. Migratory and proliferative dysfunction of these cells was corrected by exposure to angiotensin-1-7 (Ang-1-7), the protective peptide generated by ACE2. Over the duration of diabetes examined, ACE2 deficiency led to progressive reduction in electrical responses assessed by electroretinography and to increases in neural infarcts observed by fundus photography. Compared to Akita mice, ACE2 -/y -Akita at 9-months of diabetes showed an increased number of acellular capillaries indicative of more severe diabetic retinopathy. In diabetic and control human subjects, CD34 + cells, a key bone marrow HS/PC population, were assessed for changes in mRNA levels for MAS, the receptor for Ang-1-7. Levels were highest in CD34 + cells from diabetics without retinopathy. Higher serum Ang-1-7 levels predicted protection from development of retinopathy in diabetics. Treatment with Ang-1-7 or alamandine restored the impaired migration function of CD34 + cells from subjects with retinopathy. These data support that activation of the protective RAS within HS/PCs may represent a therapeutic strategy for prevention of diabetic retinopathy. This article is protected by copyright. All rights reserved. © 2018 AlphaMed Press.

Trimethyltin-activated cyclooxygenase stimulates tumor necrosis factor-alpha release from glial cells through reactive oxygen species.

PubMed

Viviani, B; Corsini, E; Pesenti, M; Galli, C L; Marinovich, M

2001-04-15

Exposure of a primary culture of glial cells to the classical neurotoxicant trimethyltin (TMT) results in the release of prostaglandin (PG)E(2) and tumor necrosis factor (TNF)-alpha. Prior treatment of glial cells with either the nonspecific inhibitor of cyclooxygenase and lypoxygenase eicosatetraynoic acid (ETYA) or the cyclooxygenase inhibitor indomethacin completely prevented TMT-induced PGE(2) production and TNF-alpha release, suggesting a role for cyclooxygenase metabolites in TMT-induced TNF-alpha release. Exposure of glial cells to increasing concentrations of PGE(2) or other prostanoids did not increase TNF-alpha synthesis, while the presence of exogenous PGE(2) during treatment of glial cells with TMT actually suppressed TNF-alpha release. The activation of arachidonic acid metabolism produces reactive oxygen species (ROS). Scavenging of ROS by means of the antioxidant trolox prevented the TMT-induced release of TNF-alpha from glial cells, while indomethacin was found to suppress ROS formation induced by 1 microM TMT in glial cells. These results suggest that activation of arachidonic acid metabolism causes TNF-alpha release through the production of ROS rather than PGE(2). Indeed, PGE(2) may exert negative feedback on the release of TNF-alpha. Copyright 2001 Academic Press.

Platelet factor XIII increases the fibrinolytic resistance of platelet-rich clots by accelerating the crosslinking of alpha 2-antiplasmin to fibrin

NASA Technical Reports Server (NTRS)

Reed, G. L.; Matsueda, G. R.; Haber, E.

1992-01-01

Platelet clots resist fibrinolysis by plasminogen activators. We hypothesized that platelet factor XIII may enhance the fibrinolytic resistance of platelet-rich clots by catalyzing the crosslinking of alpha 2-antiplasmin (alpha 2AP) to fibrin. Analysis of plasma clot structure by polyacrylamide gel electrophoresis and immunoblotting revealed accelerated alpha 2AP-fibrin crosslinking in platelet-rich compared with platelet-depleted plasma clots. A similar study of clots formed with purified fibrinogen (depleted of factor XIII activity), isolated platelets, and specific factor XIII inhibitors indicated that this accelerated crosslinking was due to the catalytic activity of platelet factor XIII. Moreover, when washed platelets were aggregated by thrombin, there was evidence of platelet factor XIII-mediated crosslinking between platelet alpha 2AP and platelet fibrin(ogen). Specific inhibition (by a monoclonal antibody) of the alpha 2AP associated with washed platelet aggregates accelerated the fibrinolysis of the platelet aggregate. Thus in platelet-rich plasma clots, and in thrombin-induced platelet aggregates, platelet factor XIII actively formed alpha 2AP-fibrin crosslinks, which appeared to enhance the resistance of platelet-rich clots to fibrinolysis.

A network of hydrophobic residues impeding helix alphaC rotation maintains latency of kinase Gcn2, which phosphorylates the alpha subunit of translation initiation factor 2.

PubMed

Gárriz, Andrés; Qiu, Hongfang; Dey, Madhusudan; Seo, Eun-Joo; Dever, Thomas E; Hinnebusch, Alan G

2009-03-01

Kinase Gcn2 is activated by amino acid starvation and downregulates translation initiation by phosphorylating the alpha subunit of translation initiation factor 2 (eIF2alpha). The Gcn2 kinase domain (KD) is inert and must be activated by tRNA binding to the adjacent regulatory domain. Previous work indicated that Saccharomyces cerevisiae Gcn2 latency results from inflexibility of the hinge connecting the N and C lobes and a partially obstructed ATP-binding site in the KD. Here, we provide strong evidence that a network of hydrophobic interactions centered on Leu-856 also promotes latency by constraining helix alphaC rotation in the KD in a manner relieved during amino acid starvation by tRNA binding and autophosphorylation of Thr-882 in the activation loop. Thus, we show that mutationally disrupting the hydrophobic network in various ways constitutively activates eIF2alpha phosphorylation in vivo and bypasses the requirement for a key tRNA binding motif (m2) and Thr-882 in Gcn2. In particular, replacing Leu-856 with any nonhydrophobic residue activates Gcn2, while substitutions with various hydrophobic residues maintain kinase latency. We further provide strong evidence that parallel, back-to-back dimerization of the KD is a step on the Gcn2 activation pathway promoted by tRNA binding and autophosphorylation. Remarkably, mutations that disrupt the L856 hydrophobic network or enhance hinge flexibility eliminate the need for the conserved salt bridge at the parallel dimer interface, implying that KD dimerization facilitates the reorientation of alphaC and remodeling of the active site for enhanced ATP binding and catalysis. We propose that hinge remodeling, parallel dimerization, and reorientation of alphaC are mutually reinforcing conformational transitions stimulated by tRNA binding and secured by the ensuing autophosphorylation of T882 for stable kinase activation.

In vitro inhibition activity of polyphenol-rich extracts from Syzygium aromaticum (L.) Merr. & Perry (Clove) buds against carbohydrate hydrolyzing enzymes linked to type 2 diabetes and Fe(2+)-induced lipid peroxidation in rat pancreas.

PubMed

Adefegha, Stephen Adeniyi; Oboh, Ganiyu

2012-10-01

To investigate and compare the inhibitory properties of free and bound phenolic extracts of clove bud against carbohydrate hydrolyzing enzymes (alpha-amylase & alpha-glucosidase) and Fe(2+)-induced lipid peroxidation in rat pancreas in vitro. The free phenolics were extracted with 80% (v/v) acetone, while bound phenolics were extracted from the alkaline and acid hydrolyzed residue with ethyl acetate. Then, the interaction of the extracts with alpha-amylase and alpha-glucosidase was subsequently assessed. Thereafter, the total phenolic contents and antioxidant activities of the extracts were determined. The result revealed that both extracts inhibited alpha-amylase and alpha-glucosidase in a dose-dependent manner. However, the alpha-glucosidase inhibitory activity of the extracts were significantly (P<0.05) higher than their alpha-amylase inhibitory activity. The free phenolics (31.67 mg/g) and flavonoid (17.28 mg/g) contents were significantly (P<0.05) higher than bound phenolic (23.52 mg/g) and flavonoid (13.70 mg/g) contents. Both extracts also exhibited high antioxidant activities as typified by their high reducing power, 1,1 diphenyl-2- picrylhydrazyl (DPPH) and 2, 2-azinobis-3-ethylbenzo-thiazoline-6-sulfonate (ABTS) radical scavenging abilities, as well as inhibition of Fe(2+)-induced lipid peroxidation in rat pancreas in vitro. This study provides a biochemical rationale by which clove elicits therapeutic effect on type 2 diabetes.

Functional coupling of rat myometrial alpha 1-adrenergic receptors to Gh alpha/tissue transglutaminase 2 during pregnancy.

PubMed

Dupuis, Morgan; Lévy, Arlette; Mhaouty-Kodja, Sakina

2004-04-30

Gh alpha protein, which exhibits both transglutaminase and GTPase activities, represents a new class of GTP-binding proteins. In the present study, we characterized Gh alpha in rat uterine smooth muscle (myometrium) and followed its expression during pregnancy by reverse transcription-PCR and Western blot. We also measured transglutaminase and GTP binding functions and used a smooth muscle cell line to evaluate the role of Gh alpha in cell proliferation. The results show that pregnancy is associated with an up-regulation of Gh alpha expression at both the mRNA and protein level. Gh alpha induced during pregnancy is preferentially localized to the plasma membrane. This was found associated with an increased ability of plasma membrane preparations to catalyze Ca(2+)-dependent incorporation of [(3)H]putrescine into casein in vitro. In the cytosol, significant changes in the level of immunodetected Gh alpha and transglutaminase activity were seen only at term. Activation of alpha1-adrenergic receptors (alpha1-AR) enhanced photoaffinity labeling of plasma membrane Gh alpha. Moreover, the level of alpha1-AR-coupled Gh alpha increased progressively with pregnancy, which parallels the active period of myometrial cell proliferation. Overexpression of wild type Gh alpha in smooth muscle cell line DDT1-MF2 increased alpha1-AR-induced [(3)H]thymidine incorporation. A similar response was obtained in cells expressing the transglutaminase inactive mutant (C277S) of Gh alpha. Together, these findings underscore the role of Gh alpha as signal transducer of alpha1-AR-induced smooth muscle cell proliferation. In this context, pregnant rat myometrium provides an interesting physiological model to study the mechanisms underlying the regulation of the GTPase function of Gh alpha

Polyhydroxy steroids and saponins from China Sea starfish Asterina pectinifera and their biological activities.

PubMed

Peng, Yan; Zheng, Jianxian; Huang, Riming; Wang, Yifei; Xu, Tunhai; Zhou, Xuefeng; Liu, Qiuying; Zeng, Fanli; Ju, Huaiqiang; Yang, Xianwen; Liu, Yonghong

2010-06-01

A new polyhydroxy sterol ester, (25S)-5alpha-cholestane-3beta,6alpha,7alpha,8,15alpha,16beta-hexahydroxyl-26-O-14'Z-eicosenoate (1), together with seven known steroid derivatives (2-8), were isolated from the EtOH extract of the whole body of China Sea starfish Asterina pectinifera. The structure of 1 was determined by using extensive spectra analysis (IR, 1D and 2D NMR, and MS), chemical degradation, and comparison with the known compound (25S)-5alpha-cholestane-3beta,6alpha,7alpha,8,15alpha,16beta,26-heptol (2). All the isolates were evaluated for their antiviral activity against herpes simplex virus type 1 (HSV-1) and their cytotoxicity against human liver carcinoma HepG2 cell line in vitro. Compounds 3-6, and 8 exhibited antiviral activity against HSV-1 virus with the minimal inhibitory concentration (MIC) values of 0.2, 0.05, 0.2, 0.22, and 0.07 microM, respectively. While compounds 4 and 5 exhibited cytotoxicity against HepG2 cells with IC(50) values of 0.2 and 1.6 microM, respectively.

Characterization of the specificities of human blood group H gene-specified alpha 1,2-L-fucosyltransferase toward sulfated/sialylated/fucosylated acceptors: evidence for an inverse relationship between alpha 1,2-L-fucosylation of Gal and alpha 1,6-L-fucosylation of asparagine-linked GlcNAc.

PubMed

Chandrasekaran, E V; Jain, R K; Larsen, R D; Wlasichuk, K; Matta, K L

1996-07-09

The assembly of complex structures bearing the H determinant was examined by characterizing the specificities of a cloned blood group H gene-specified alpha 1,2-L-fucosyltransferase (FT) toward a variety of sulfated, sialylated, or fucosylated Gal beta 1,3/4GlcNAc beta- or Gal beta 1,3GalNAc alpha-based acceptor structures. (a) As compared to the basic type 2, Gal beta 1,4GlcNAc beta-(K(m) = 1.67 mM), the basic type 1 was 137% active (K(m) = 0.83 mM). (b) On C-6 sulfation of Gal, type 1 became 142.1% active and type 2 became 223.0% active (K(m) = 0.45 mM). (c) On C-6 sulfation of GlcNAc, type 2 showed 33.7% activity. (d) On C-3 or C-4 fucosylation of GlcNAc, both types 1 and 2 lost activity. (e) Type 1 showed 70.8% and 5.8% activity, respectively, on C-6 and C-4 O-methylation of GlcNAc. (f) Type 1 retained 18.8% activity on alpha 2,6-sialylation of GlcNAc. (g) Terminal type 1 or 2 of extended chain had lower activity. (h) With Gal in place of GlcNAc in type 1, the activity became 43.2%. (i) Compounds with terminal alpha 1,3-linked Gal were inactive. (j) Gal beta 1,3GalNAc alpha- (the T-hapten) was approximately 0.4-fold as active as Gal beta 1,4GlcNAc beta-. (k) C-6 sulfation of Gal on the T-hapten did not affect the acceptor activity. (l) C-6 sulfation of GalNAc decreased the activity to 70%, whereas on C-6 sulfation of both Gal and GalNAc the T-hapten lost the acceptor ability. (m) C-6 sialylation of GalNAc also led to inactivity. (n) beta 1,6 branching from GalNAc of the T-hapten by a GlcNAc residue or by units such as Gal beta 1, 4GlcNAc-, Gal beta 1,4(Fuc alpha 1,3)GlcNAc-, or 3-sulfoGal beta 1,4GlcNAc- resulted in 111.9%, 282.8%, 48.3%, and 75.3% activities, respectively. (o) The enhancement of enzyme affinity by a sulfo group on C-6 of Gal was demonstrated by an increase (approximately 5-fold) in the K(m) for Gal beta 1,4GlcNAc beta 1,6(Gal beta 1,3)GalNAc alpha-O-Bn in presence of 6-sulfoGal beta 1,- 4GlcNAc beta-O-Me (3.0 mM). (p) Among the two sites in Gal beta 1, 4GlcNAc beta 1,6(Gal beta 1,3) GalNAc alpha-O-Bn, the enzyme had a higher affinity ( > 3-fold) for the Gal linked to GlcNAc. (q) With respect to Gal beta 1,- 3GlcNAc beta-O-Bn (3.0 mM), fetuin triantennary asialo glycopeptide (2.4 mM), bovine IgG diantennary glycopeptide (2.8 mM), asialo Cowper's gland mucin (0.06 mM), and the acrylamide copolymers (0.125 mM each) containing Gal beta 1,3GlcNAc beta-, Gal beta 1,3(6-sulfo)GlcNAc beta-, Gal beta 1,3GalNAc alpha-, Gal beta 1,3Gal beta-, or Gal alpha 1,3Gal beta- units were 153.6%, 43.0%, 6.2%, 52.5%, 94.9%, 14.7%, 23.6%, and 15.6% active, respectively. (r) Fucosylation by alpha 1,2-L-FT of the galactosyl residue which occurs on the antennary structure of the bovine IgG glycopeptide was adversely affected by the presence of an alpha 1,6-L-fucosyl residue located on the distant glucosaminyl residue that is directly attached to the asparagine of the protein backbone. This became evident from the 4-fold activity of alpha 1,2-L-FT toward bovine IgG glycopeptide after approximately 5% removal of alpha 1,6-linked Fuo.

Morphological modification of alpha-MnO2 catalyst for use in Li/air batteries.

PubMed

Park, Min-Sik; Kim, Jae-Hun; Kim, Ki Jae; Jeong, Goojin; Kim, Young-Jun

2013-05-01

Single crystal alpha-MnO2 nanowires and nanopowders have been successfully synthesized in order to facilitate a comparison of their catalytic activity for use in Li-air batteries. The importance of the morphological modification of the alpha-MnO2 catalyst for facilitating electrochemical reactions between Li and O2 is addressed. Distinctive catalytic activity of alpha-MnO2 is observed, which is in line with its different morphologies. The catalytic activity significantly affects the reversible capacity of Li-air batteries. A high aspect ratio, large surface area and good dispersibility of alpha-MnO2 in the nanowire form are advantageous providing larger active surfaces for promoting the fundamental reactions in Li-air batteries. We also introduce a robustly designed air-electrode composed of highly porous carbon and nanostructured alpha-MnO2 catalysts, with employs a metal foam current collector to ensure sufficient air-permeability and to maximize electronic conduction during cycles. Our suggestions should prove helpful in forming a basis for further investigations in developing advanced Li-air batteries.

Effects of tumor necrosis factor-alpha and interferon-gamma on expressions of matrix metalloproteinase-2 and -9 in human bladder cancer cells.

PubMed

Shin, K Y; Moon, H S; Park, H Y; Lee, T Y; Woo, Y N; Kim, H J; Lee, S J; Kong, G

2000-10-31

We have investigated the effects of tumor necrosis factor-alpha (TNF-alpha) and interferon (INF-gamma), the potent Bacillus Calmette-Guerin (BCG)-induced cytokines on the production of MMP-2, MMP-9, TIMP-1, TIMP-2 and MT1-MMP in high grade human bladder cancer cell lines, T-24, J-82 and HT-1376 cell lines. MMP-2 expression and activity were decreased in T-24 cells treated with both cytokines in a dose dependent manner. However, J-82 cells treated with TNF-alpha and INF-gamma revealed dose dependent increases of MMP-9 expression and activity with similar baseline expression and activity of MMP-2. HT-1376 cells after exposure to TNF-alpha only enhanced the expression and activity of MMP-9. These results indicate that TNF-alpha and INF-gamma could regulate the production of MMP-2 or MMP-9 on bladder cancer cells and their patterns of regulation are cell specific. Furthermore, this diverse response of bladder cancer cells to TNF-alpha and INF-gamma suggests that BCG immunotherapy may enhance the invasiveness of bladder cancer in certain conditions with induction of MMPs.

Alpha 2-macroglobulin capture allows detection of mast cell chymase in serum and creates a reservoir of angiotensin II-generating activity.

PubMed

Raymond, Wilfred W; Su, Sharon; Makarova, Anastasia; Wilson, Todd M; Carter, Melody C; Metcalfe, Dean D; Caughey, George H

2009-05-01

Human chymase is a highly efficient angiotensin II-generating serine peptidase expressed by mast cells. When secreted from degranulating cells, it can interact with a variety of circulating antipeptidases, but is mostly captured by alpha(2)-macroglobulin, which sequesters peptidases in a cage-like structure that precludes interactions with large protein substrates and inhibitors, like serpins. The present work shows that alpha(2)-macroglobulin-bound chymase remains accessible to small substrates, including angiotensin I, with activity in serum that is stable with prolonged incubation. We used alpha(2)-macroglobulin capture to develop a sensitive, microtiter plate-based assay for serum chymase, assisted by a novel substrate synthesized based on results of combinatorial screening of peptide substrates. The substrate has low background hydrolysis in serum and is chymase-selective, with minimal cleavage by the chymotryptic peptidases cathepsin G and chymotrypsin. The assay detects activity in chymase-spiked serum with a threshold of approximately 1 pM (30 pg/ml), and reveals native chymase activity in serum of most subjects with systemic mastocytosis. alpha(2)-Macroglobulin-bound chymase generates angiotensin II in chymase-spiked serum, and it appears in native serum as chymostatin-inhibited activity, which can exceed activity of captopril-sensitive angiotensin-converting enzyme. These findings suggest that chymase bound to alpha(2)-macroglobulin is active, that the complex is an angiotensin-converting enzyme inhibitor-resistant reservoir of angiotensin II-generating activity, and that alpha(2)-macroglobulin capture may be exploited in assessing systemic release of secreted peptidases.

[EEG alpha indices in dependence on the menstrual cycle phase and salivary progesterone].

PubMed

Bazanova, O M; Kondratenko, A V; Kuz'minova, O I; Muravleva, K B; Petrova, S E

2014-01-01

The effects of the neurohumoral status on the EEG alpha - activity indices were studied in a within-subject design with 78 women aged 18-27 years during 1-2 menstrual cycle. Psychometric and EEG indices of alpha waves basal body temperature, saliva progesterone and cortisol level were monitored every 2-3 days. Menstrual and follicular recording sessions occurred before the ovulatory temperature rise, luteal recording session--after increasing progesterone level more than 20% respect to previous day and premenstrual sessions after decreasing progesterone level more that 20% respect to previous day. The design consisted of rest and task periods EEG, EMG and ECG recordings. Half the subjects began during their menstrual phase and half began during their luteal phase. All 5 phases were compared for differences between psychometric features EEG alpha activity, EMG and ECG baseline resting levels, as well as for reactivity to cognitive task. The results showed menstrual phase differences in all psychometric and alpha EEG indices. The cognitive fluency, alpha peak frequency, alpha band width, power in alpha-2 frequency range are maximal at luteal, alpha visual activation and reactivity to cognitive task performance--at follicular phase. The hypothesis that the EEG alpha activity depends on the hormonal status supported by the positive association salivary progesterone level with the alpha peak frequency, power in the alpha-2 band and negative--with the power of the alpha-1 band. According these results, we conclude that psycho-physiological recording sessions with women might be provided with a glance to phase of menstrual cycle.

Acetylsalicylic acid regulates MMP-2 activity and inhibits colorectal invasion of murine B16F0 melanoma cells in C57BL/6J mice: effects of prostaglandin F(2)alpha.

PubMed

Tsai, Chin-Shaw Stella; Luo, Shue-Fen; Ning, Chung-Chu; Lin, Chien-Liang; Jiang, Ming-Chung; Liao, Ching-Fong

2009-08-01

Epidemiological studies indicate that acetylsalicylic acid may reduce the risk of mortality due to colon cancers. Metastasis is the major cause of cancer death. Matrix metalloproteinases (MMPs) play important roles in tumor invasion regulation, and prostaglandin F(2)alpha (PGF(2)alpha) is a key stimulator of MMP production. Thus, we investigated whether acetylsalicylic acid regulated MMP activity and the invasion of cancer cells and whether PGF(2)alpha attenuated acetylsalicylic acid-inhibited invasion of cancer cells. Gelatin-based zymography assays showed that acetylsalicylic acid inhibited the MMP-2 activity of B16F0 melanoma cells. Matrigel-based chemoinvasion assays showed that acetylsalicylic acid inhibited the invasion of B16F0 cells. Acetylsalicylic acid can inhibit PGF(2)alpha synthesis and PGF(2)alpha is a key stimulator of MMP-2 production. Our data showed that PGF(2)alpha treatment attenuated the acetylsalicylic acid-inhibited invasion of B16F0 cells. In animal experiments, acetylsalicylic acid reduced colorectal metastasis of B16F0 cells in C57BL/6J mice by 44%. Our results suggest that PGF(2)alpha is a therapeutic target for metastasis inhibition and acetylsalicylic acid may possess anti-metastasis ability.

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

Wang, Cheng-hu; Cao, Guo-Fan; Jiang, Qin, E-mail: Jqin710@vip.sina.com

Highlights: Black-Right-Pointing-Pointer TNF-{alpha} induces MMP-9 expression and secretion to promote RPE cell migration. Black-Right-Pointing-Pointer MAPK activation is not critical for TNF-{alpha}-induced MMP-9 expression. Black-Right-Pointing-Pointer Akt and mTORC1 signaling mediate TNF-{alpha}-induced MMP-9 expression. Black-Right-Pointing-Pointer SIN1 knockdown showed no significant effect on MMP-9 expression by TNF-{alpha}. -- Abstract: Tumor necrosis factor-alpha (TNF-{alpha}) promotes in vitro retinal pigment epithelial (RPE) cell migration to initiate proliferative vitreoretinopathy (PVR). Here we report that TNF-{alpha} promotes human RPE cell migration by inducing matrix metallopeptidase 9 (MMP-9) expression. Inhibition of MMP-9 by its inhibitor or its neutralizing antibody inhibited TNF-{alpha}-induced in vitro RPE cell migration. Reversely, exogenously-addedmore » active MMP-9 promoted RPE cell migration. Suppression Akt/mTOR complex 1(mTORC1) activation by LY 294002 and rapamycin inhibited TNF-{alpha}-mediated MMP-9 expression. To introduce a constitutively active Akt (CA-Akt) in cultured RPE cells increased MMP-9 expression, and to block mTORC1 activation by rapamycin inhibited its effect. RNA interference (RNAi)-mediated silencing of SIN1, a key component of mTOR complex 2 (mTORC2), had no effect on MMP-9 expression or secretion. In conclusion, this study suggest that TNF-{alpha} promotes RPE cell migration by inducing MMP-9 expression through activation of Akt/ mTORC1, but not mTORC2 signaling.« less

Atrial natriuretic peptide regulates lipid mobilization and oxygen consumption in human adipocytes by activating AMPK

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

Souza, Sandra C.; Chau, Mary D.L.; Yang, Qing

2011-07-08

Highlights: {yields} Treatment of differentiated human adipocytes with atrial natriuretic peptide (ANP) increased lipolysis and oxygen consumption by activating AMP-activated protein kinase (AMPK). {yields} ANP stimulated lipid mobilization by selective activation of the alpha2 subunit of AMPK and increased energy utilization through activation of both the alpha1 and alpha2 subunits of AMPK. {yields} ANP enhanced adipocyte mitochondrial oxidative capacity as evidenced by induction of oxidative mitochondrial genes and increase in oxygen consumption. {yields} Exposure of human adipocytes to fatty acids and (TNF{alpha}) induced insulin resistance and decreased expression of mitochondrial genes which was restored to normal by ANP. -- Abstract:more » Atrial natriuretic peptide (ANP) has been shown to regulate lipid and carbohydrate metabolism providing a possible link between cardiovascular function and metabolism by mediating the switch from carbohydrate to lipid mobilization and oxidation. ANP exerts a potent lipolytic effect via cGMP-dependent protein kinase (cGK)-I mediated-stimulation of AMP-activated protein kinase (AMPK). Activation of the ANP/cGK signaling cascade also promotes muscle mitochondrial biogenesis and fat oxidation. Here we demonstrate that ANP regulates lipid metabolism and oxygen utilization in differentiated human adipocytes by activating the alpha2 subunit of AMPK. ANP treatment increased lipolysis by seven fold and oxygen consumption by two fold, both of which were attenuated by inhibition of AMPK activity. ANP-induced lipolysis was shown to be mediated by the alpha2 subunit of AMPK as introduction of dominant-negative alpha2 subunit of AMPK attenuated ANP effects on lipolysis. ANP-induced activation of AMPK enhanced mitochondrial oxidative capacity as evidenced by a two fold increase in oxygen consumption and induction of mitochondrial genes, including carnitine palmitoyltransferase 1A (CPT1a) by 1.4-fold, cytochrome C (CytC) by 1.3-fold, and peroxisome proliferator-activated receptor-{gamma} coactivator-1{alpha} (PGC-1{alpha}) by 1.4-fold. Treatment of human adipocytes with fatty acids and tumor necrosis factor {alpha} (TNF{alpha}) induced insulin resistance and down-regulation of mitochondrial genes, which was restored by ANP treatment. These results show that ANP regulates lipid catabolism and enhances energy dissipation through AMPK activation in human adipocytes.« less

The fibroblast growth factor receptor (FGFR) agonist FGF1 and the neural cell adhesion molecule-derived peptide FGL activate FGFR substrate 2alpha differently.

PubMed

Chen, Yongshuo; Li, Shizhong; Berezin, Vladimir; Bock, Elisabeth

2010-07-01

Activation of fibroblast growth factor (FGF) receptors (FGFRs) both by FGFs and by the neural cell adhesion molecule (NCAM) is crucial in the development and function of the nervous system. We found that FGFR substrate 2alpha (FRS2alpha), Src homologous and collagen A (ShcA), and phospholipase-Cgamma (PLCgamma) were all required for neurite outgrowth from cerebellar granule neurons (CGNs) induced by FGF1 and FGL (an NCAM-derived peptide agonist of FGFR1). Like FGF1, FGL induced tyrosine phosphorylation of FGFR1, FRS2alpha, ShcA, and PLCgamma in a time- and dose-dependent manner. However, the activation of FRS2alpha by FGL was significantly lower than the activation by FGF1, indicating a differential signaling profile induced by NCAM compared with the cognate growth factor.

Improve the catalytic activity of {alpha}-Fe{sub 2}O{sub 3} particles in decomposition of ammonium perchlorate by coating amorphous carbon on their surface

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

Zhang Yifu; Liu Xinghai, E-mail: liuxh@whu.edu.c; Nie Jiaorong

2011-02-15

Sphere- and pod-like {alpha}-Fe{sub 2}O{sub 3} particles have been selectively synthesized using NH{sub 3}.H{sub 2}O and NaOH solution to adjust the pH value of the designed synthetic system, respectively. The sphere-like {alpha}-Fe{sub 2}O{sub 3} particles with diameter about 25 nm on average were encapsulated into carbon shells to fabricate a novel core-shell composite ({alpha}-Fe{sub 2}O{sub 3}-C) through the coating experiments. The catalytic performance of the products on the thermal decomposition of ammonium perchlorate (AP) was investigated by thermal gravimetric analyzer (TG) and differential thermal analysis (DTA). The thermal decomposition temperatures of AP in the presence of pod-like {alpha}-Fe{sub 2}O{sub 3},more » sphere-like {alpha}-Fe{sub 2}O{sub 3} and {alpha}-Fe{sub 2}O{sub 3}-C are reduced by 72, 81 and 109 {sup o}C, respectively, which show that {alpha}-Fe{sub 2}O{sub 3}-C core-shell composites have higher catalytic activity than that of {alpha}-Fe{sub 2}O{sub 3}. -- Graphical abstract: The catalytic performance of pod-like {alpha}-Fe{sub 2}O{sub 3}, sphere-like {alpha}-Fe{sub 2}O{sub 3} and {alpha}-Fe{sub 2}O{sub 3}-C on the thermal decomposition of ammonium perchlorate (AP). Display Omitted Research highlights: {yields} Sphere- and pod-like {alpha}-Fe{sub 2}O{sub 3} particles have been selectively synthesized using NH{sub 3}.H{sub 2}O and NaOH solution to adjust the pH value. {yields} A novel core-shell composite ({alpha}-Fe{sub 2}O{sub 3}-C core-shell structured composite) has been successfully synthesized using sphere-like {alpha}-Fe{sub 2}O{sub 3} particles as the cores and glucose as the source of carbon. {yields} The thermal decomposition temperatures of AP in the presence of pod-like {alpha}-Fe{sub 2}O{sub 3}, sphere-like {alpha}-Fe{sub 2}O{sub 3} and {alpha}-Fe{sub 2}O{sub 3}-C are reduced by 72, 81 and 109 {sup o}C, respectively, which shows that these materials have high catalytic activity.« less

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

Kimura, Rino; Takahashi, Nobuyuki, E-mail: nobu@kais.kyoto-u.ac.jp; Murota, Kaeko

Highlights: {yields} PPAR{alpha} activation increased mRNA expression levels of fatty acid oxidation-related genes in human intestinal epithelial Caco-2 cells. {yields} PPAR{alpha} activation also increased oxygen consumption rate and CO{sub 2} production and decreased secretion of triglyceride and ApoB from Caco-2 cells. {yields} Orally administration of bezafibrate increased mRNA expression levels of fatty acid oxidation-related genes and CO{sub 2} production in small intestinal epithelial cells. {yields} Treatment with bezafibrate decreased postprandial serum concentration of triglyceride after oral injection of olive oil in mice. {yields} It suggested that intestinal lipid metabolism regulated by PPAR{alpha} activation suppresses postprandial lipidemia. -- Abstract: Activation ofmore » peroxisome proliferator-activated receptor (PPAR)-{alpha} which regulates lipid metabolism in peripheral tissues such as the liver and skeletal muscle, decreases circulating lipid levels, thus improving hyperlipidemia under fasting conditions. Recently, postprandial serum lipid levels have been found to correlate more closely to cardiovascular diseases than fasting levels, although fasting hyperlipidemia is considered an important risk of cardiovascular diseases. However, the effect of PPAR{alpha} activation on postprandial lipidemia has not been clarified. In this study, we examined the effects of PPAR{alpha} activation in enterocytes on lipid secretion and postprandial lipidemia. In Caco-2 enterocytes, bezafibrate, a potent PPAR{alpha} agonist, increased mRNA expression levels of fatty acid oxidation-related genes, such as acyl-CoA oxidase, carnitine palmitoyl transferase, and acyl-CoA synthase, and oxygen consumption rate (OCR) and suppressed secretion levels of both triglycerides and apolipoprotein B into the basolateral side. In vivo experiments revealed that feeding high-fat-diet containing bezafibrate increased mRNA expression levels of fatty acid oxidation-related genes and production of CO{sub 2} and acid soluble metabolites in enterocytes. Moreover, bezafibrate treatment suppressed postprandial lipidemia after oral administration of olive oil to the mice. These findings indicate that PPAR{alpha} activation suppresses postprandial lipidemia through enhancement of fatty acid oxidation in enterocytes, suggesting that intestinal lipid metabolism regulated by PPAR{alpha} activity is a novel target of PPAR{alpha} agonist for decreasing circulating levels of lipids under postprandial conditions.« less

Vascular endothelial cells express isoforms of protein kinase A inhibitor.

PubMed

Lum, Hazel; Hao, Zengping; Gayle, Dave; Kumar, Priyadarsini; Patterson, Carolyn E; Uhler, Michael D

2002-01-01

The expression and function of the endogenous inhibitor of cAMP-dependent protein kinase (PKI) in endothelial cells are unknown. In this study, overexpression of rabbit muscle PKI gene into endothelial cells inhibited the cAMP-mediated increase and exacerbated thrombin-induced decrease in endothelial barrier function. We investigated PKI expression in human pulmonary artery (HPAECs), foreskin microvessel (HMECs), and brain microvessel endothelial cells (HBMECs). RT-PCR using specific primers for human PKI alpha, human PKI gamma, and mouse PKI beta sequences detected PKI alpha and PKI gamma mRNA in all three cell types. Sequencing and BLAST analysis indicated that forward and reverse DNA strands for PKI alpha and PKI gamma were of >96% identity with database sequences. RNase protection assays showed protection of the 542 nucleotides in HBMEC and HPAEC PKI alpha mRNA and 240 nucleotides in HBMEC, HPAEC, and HMEC PKI gamma mRNA. Western blot analysis indicated that PKI gamma protein was detected in all three cell types, whereas PKI alpha was found in HBMECs. In summary, endothelial cells from three different vascular beds express PKI alpha and PKI gamma, which may be physiologically important in endothelial barrier function.

Stress and vascular responses: atheroprotective effect of laminar fluid shear stress in endothelial cells: possible role of mitogen-activated protein kinases.

PubMed

Yoshizumi, Masanori; Abe, Jun-Ichi; Tsuchiya, Koichiro; Berk, Bradford C; Tamaki, Toshiaki

2003-03-01

Atherosclerosis preferentially occurs in areas of turbulent blood flow and low fluid shear stress, whereas laminar blood flow and high shear stress are atheroprotective. Inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-alpha), stimulate expression of endothelial cell (EC) genes that may promote atherosclerosis. Recent findings suggest a steady laminar blood flow decreases EC apoptosis and inhibits TNF-mediated EC activation. EC apoptosis or activation is suggested to be involved in plaque erosion, which may lead to platelet aggregation. TNF-alpha regulates gene expression in ECs, in part, by stimulating mitogen-activated protein (MAP) kinases, which phosphorylate transcription factors. We hypothesized that steady laminar flow inhibits cytokine-mediated activation of MAP kinases in ECs. To test this hypothesis, we determined the effects of steady laminar flow (shear stress = 12 dynes/cm(2)) on TNF-alpha-stimulated activity of three MAP kinases in human umbilical vein ECs (HUVEC): extracellular signal-regulated kinase (ERK1/2), c-Jun N-terminal kinase (JNK), and p38. TNF-alpha activated ERK1/2, JNK, and p38 maximally at 15 min in HUVEC. Pre-exposing HUVEC for 10 min to flow inhibited TNF-alpha activation of JNK, but showed no significant effect on ERK1/2 or p38 activation. Incubation of HUVEC with PD98059, a specific ERK1/2 inhibitor, blocked the flow-mediated inhibition of TNF activation of JNK. Transfection studies with dominant-negative constructs of the protein kinase MEK5 suggested an important role for big mitogen-activated protein kinase 1 (BMK1) in flow-mediated regulation of EC activation by TNF-alpha. Understanding the mechanisms by which steady laminar flow regulates JNK activation by cytokines may provide insight into the atheroprotective mechanisms induced by laminar blood flow.

Nrf2 Deficiency Exacerbates Obesity-Induced Oxidative Stress, Neurovascular Dysfunction, Blood-Brain Barrier Disruption, Neuroinflammation, Amyloidogenic Gene Expression, and Cognitive Decline in Mice, Mimicking the Aging Phenotype.

PubMed

Tarantini, Stefano; Valcarcel-Ares, M Noa; Yabluchanskiy, Andriy; Tucsek, Zsuzsanna; Hertelendy, Peter; Kiss, Tamas; Gautam, Tripti; Zhang, Xin A; Sonntag, William E; de Cabo, Rafael; Farkas, Eszter; Elliott, Michael H; Kinter, Michael T; Deak, Ferenc; Ungvari, Zoltan; Csiszar, Anna

2018-06-14

Obesity has deleterious effects on cognitive function in the elderly adults. In mice, aging exacerbates obesity-induced oxidative stress, microvascular dysfunction, blood-brain barrier (BBB) disruption, and neuroinflammation, which compromise cognitive health. However, the specific mechanisms through which aging and obesity interact to remain elusive. Previously, we have shown that Nrf2 signaling plays a critical role in microvascular resilience to obesity and that aging is associated with progressive Nrf2 dysfunction, promoting microvascular impairment. To test the hypothesis that Nrf2 deficiency exacerbates cerebromicrovascular dysfunction induced by obesity Nrf2+/+ and Nrf2-/-, mice were fed an adipogenic high-fat diet (HFD). Nrf2 deficiency significantly exacerbated HFD-induced oxidative stress and cellular senescence, impairment of neurovascular coupling responses, BBB disruption, and microglia activation, mimicking the aging phenotype. Obesity in Nrf2-/- mice elicited complex alterations in the amyloidogenic gene expression profile, including upregulation of amyloid precursor protein. Nrf2 deficiency and obesity additively reduced long-term potentiation in the CA1 area of the hippocampus. Collectively, Nrf2 dysfunction exacerbates the deleterious effects of obesity, compromising cerebromicrovascular and brain health by impairing neurovascular coupling mechanisms, BBB integrity and synaptic function and promoting neuroinflammation. These results support a possible role for age-related Nrf2 dysfunction in the pathogenesis of vascular cognitive impairment and Alzheimer's disease.

Estrogen-related receptor {alpha} is essential for the expression of antioxidant protection genes and mitochondrial function

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

Rangwala, Shamina M.; Li, Xiaoyan; Lindsley, Loren

2007-05-25

Estrogen-related receptor {alpha} (ERR{alpha}) is an important mediator of mitochondrial biogenesis and function. To investigate the transcriptional network controlling these phenomena, we investigated mitochondrial gene expression in embryonic fibroblasts isolated from ERR{alpha} null mice. Peroxisome proliferator-activated receptor {gamma} coactivator-1{alpha} (PGC-1{alpha}) stimulated mitochondrial gene expression program in control cells, but not in the ERR{alpha} null cells. Interestingly, the induction of levels of mitochondrial oxidative stress protection genes in response to increased PGC-1{alpha} levels was dependent on ERR{alpha}. Furthermore, we found that the PGC-1{alpha}-mediated induction of estrogen-related receptor {gamma} and nuclear respiratory factor 2 (NRF-2), was dependent on the presence of ERR{alpha}.more » Basal levels of NRF-2 were decreased in the absence of ERR{alpha}. The absence of ERR{alpha} resulted in a decrease in citrate synthase enzyme activity in response to PGC-1{alpha} overexpression. Our results indicate an essential role for ERR{alpha} as a key regulator of oxidative metabolism.« less

Dysfunction of protein kinase FA/GSK-3 alpha in lymphocytes of patients with schizophrenic disorder.

PubMed

Yang, S D; Yu, J S; Lee, T T; Yang, C C; Ni, M H; Yang, Y Y

1995-09-01

As compared to normal people, the lymphocytes of patients with schizophrenia were found to have an impairment of ATP.Mg-dependent protein phosphatase activation. More importantly, the impaired protein phosphatase activation in the lymphocytes of schizophrenic patients could be consistently and completely restored to normal by exogenous pure protein kinase FA/glycogen synthase kinase-3 alpha (kinase FA/GSK-3 alpha) (the activating factor of ATP.Mg-dependent protein phosphatase), indicating that the molecular mechanism for the impaired protein phosphatase activation in schizophrenic patients may be due to a functional loss of kinase FA/GSK-3 alpha. Immunoblotting and kinase activity analysis in an anti-kinase FA/GSK-3 alpha immunoprecipitate further demonstrate that both cellular activities and protein levels of kinase FA/GSK-3 alpha in the lymphocytes of schizophrenic patients were greatly impared as compared to normal controls. Statistical analysis revealed that the lymphocytes isolated from 37 normal people contain kinase FA/GSK-3 alpha activity in the high levels of 14.8 +/- 2.4 units/mg of cell protein, whereas the lymphocytes of 48 patients with schizophrenic disorder contain kinase FA/GSK-3 alpha activity in the low levels of 2.8 +/- 1.6 units/mg, indicating that the different levels of kinase FA/GSK-3 alpha activity between schizophrenic patients and normal people are statistically significant. Taken together, the results provide initial evidence that patients with schizophrenic disorder may have a common impairment in the protein levels and cellular activities of kinase FA/GSK-3 alpha, a multisubstrate protein kinase and a multisubstrate protein phosphatase activator in their lymphocytes.

Activation of peroxisome proliferator-activated receptor-{alpha} enhances fatty acid oxidation in human adipocytes

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

Lee, Joo-Young; Hashizaki, Hikari; Goto, Tsuyoshi

2011-04-22

Highlights: {yields} PPAR{alpha} activation increased mRNA expression levels of adipocyte differentiation marker genes and GPDH activity in human adipocytes. {yields} PPAR{alpha} activation also increased insulin-dependent glucose uptake in human adipocytes. {yields} PPAR{alpha} activation did not affect lipid accumulation in human adipocytes. {yields} PPAR{alpha} activation increased fatty acid oxidation through induction of fatty acid oxidation-related genes in human adipocytes. -- Abstract: Peroxisome proliferator-activated receptor-{alpha} (PPAR{alpha}) is a key regulator for maintaining whole-body energy balance. However, the physiological functions of PPAR{alpha} in adipocytes have been unclarified. We examined the functions of PPAR{alpha} using human multipotent adipose tissue-derived stem cells as a humanmore » adipocyte model. Activation of PPAR{alpha} by GW7647, a potent PPAR{alpha} agonist, increased the mRNA expression levels of adipocyte differentiation marker genes such as PPAR{gamma}, adipocyte-specific fatty acid-binding protein, and lipoprotein lipase and increased both GPDH activity and insulin-dependent glucose uptake level. The findings indicate that PPAR{alpha} activation stimulates adipocyte differentiation. However, lipid accumulation was not changed, which is usually observed when PPAR{gamma} is activated. On the other hand, PPAR{alpha} activation by GW7647 treatment induced the mRNA expression of fatty acid oxidation-related genes such as CPT-1B and AOX in a PPAR{alpha}-dependent manner. Moreover, PPAR{alpha} activation increased the production of CO{sub 2} and acid soluble metabolites, which are products of fatty acid oxidation, and increased oxygen consumption rate in human adipocytes. The data indicate that activation of PPAR{alpha} stimulates both adipocyte differentiation and fatty acid oxidation in human adipocytes, suggesting that PPAR{alpha} agonists could improve insulin resistance without lipid accumulation in adipocytes. The expected effects of PPAR{alpha} activation are very valuable for managing diabetic conditions accompanied by obesity, because PPAR{gamma} agonists, usually used as antidiabetic drugs, induce excessive lipid accumulation in adipocytes in addition to improvement of insulin resistance.« less

Mutant HNF-1{alpha} and mutant HNF-1{beta} identified in MODY3 and MODY5 downregulate DPP-IV gene expression in Caco-2 cells

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

Gu Ning; Laboratory of Neurochemistry, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto; Adachi, Tetsuya

2006-08-04

Dipeptidylpeptidase IV (DPP-IV) is a well-documented drug target for the treatment of type 2 diabetes. Hepatocyte nuclear factors (HNF)-1{alpha} and HNF-1{beta}, known as the causal genes of MODY3 and MODY5, respectively, have been reported to be involved in regulation of DPP-IV gene expression. But, it is not completely clear (i) that they play roles in regulation of DPP-IV gene expression, and (ii) whether DPP-IV gene activity is changed by mutant HNF-1{alpha} and mutant HNF-1{beta} in MODY3 and MODY5. To explore these questions, we investigated transactivation effects of wild HNF-1{alpha} and 13 mutant HNF-1{alpha}, as well as wild HNF-1{beta} and 2more » mutant HNF-1{beta}, on DPP-IV promoter luciferase gene in Caco-2 cells by means of a transient experiment. Both wild HNF-1{alpha} and wild HNF-1{beta} significantly transactivated DPP-IV promoter, but mutant HNF-1{alpha} and mutant HNF-1{beta} exhibited low transactivation activity. Moreover, to study whether mutant HNF-1{alpha} and mutant HNF-1{beta} change endogenous DPP-IV enzyme activity, we produced four stable cell lines from Caco-2 cells, in which wild HNF-1{alpha} or wild HNF-1{beta}, or else respective dominant-negative mutant HNF-1{alpha}T539fsdelC or dominant-negative mutant HNF-1{beta}R177X, was stably expressed. We found that DPP-IV gene expression and enzyme activity were significantly increased in wild HNF-1{alpha} cells and wild HNF-1{beta} cells, whereas they decreased in HNF-1{alpha}T539fsdelC cells and HNF-1{beta}R177X cells, compared with DPP-IV gene expression and enzyme activity in Caco-2 cells. These results suggest that both wild HNF-1{alpha} and wild HNF-1{beta} have a stimulatory effect on DPP-IV gene expression, but that mutant HNF-1{alpha} and mutant HNF-1{beta} attenuate the stimulatory effect.« less

Methanol extract of Xanthium strumarium L. possesses anti-inflammatory and anti-nociceptive activities.

PubMed

Kim, In-Tae; Park, Young-Mi; Won, Jong-Heon; Jung, Hyun-Ju; Park, Hee-Juhn; Choi, Jong-Won; Lee, Kyung-Tae

2005-01-01

As an attempt to identify bioactive natural products with anti-inflammatory activity, we evaluated the effects of the methanol extract of the semen of Xanthium strumarium L. (MEXS) on lipopolysaccharide (LPS)-induced nitric oxide (NO), prostaglandin E2 (PGE2) and tumor necrosis factor-alpha (TNF-alpha) production in RAW 264.7 cells. Our data indicate that MEXS is a potent inhibitor of NO, PGE2 and TNF-alpha production. Consistent with these findings, the expression levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein and iNOS, COX-2 and TNF-alpha mRNA were down-regulated in a concentration-dependent manner. Furthermore, MEXS inhibited nuclear factor kappa B (NF-kappaB) DNA binding activity and the translocation of NF-kappaB to the nucleus by blocking the degradation of inhibitor of kappa B-alpha (IkappaB-alpha). We further evaluated the anti-inflammatory and anti-nociceptive activities of MEXS in vivo. MEXS (100, 200 mg/kg/d, p.o.) reduced acute paw edema induced by carrageenin in rats, and showed analgesic activities in an acetic acid-induced abdominal constriction test and a hot plate test in mice. Thus, our study suggests that the inhibitions of iNOS, COX-2 expression, and TNF-alpha release by the methanol extract of the semen of Xanthium strumarium L. are achieved by blocking NF-kappaB activation, and that this is also responsible for its anti-inflammatory effects.

Protein kinase C is involved in cyclic adenosine monophosphate formation due to PGF2 alpha desensitization in bovine iris sphincter.

PubMed

Tachado, S D; Zhang, Y; Abdel-Latif, A A

1993-05-01

To examine the mechanisms underlying the effects of PGF2 alpha receptor desensitization on agonist-induced second messenger formation and contraction in bovine iris sphincter. Short-term PGF2 alpha receptor desensitization of the bovine iris sphincter was carried out by incubating the tissue in Krebs-Ringer bicarbonate buffer containing 25 microM PGF2 alpha for 45 min at 37 degrees C. The effects of PGF2 alpha and other pharmacologic agents on inositol 1,4,5-triphosphate (IP3) production and cyclic adenosine monophosphate (cAMP) formation in desensitized and nondesensitized tissues were monitored by anion-exchange chromatography and radioimmunoassay. In the isolated bovine iris sphincter, protein kinase C (PKC) is involved in the activation of adenylate cyclase and the desensitization of prostaglandin F2 alpha receptor-mediated responses supported by these findings. (A) Exposure of the tissue to phorbol 12,13-dibutyrate, used to activate PKC, enhanced basal cAMP formation in a dose (EC50 = 8.8 x 10(-8) M) and time (t1/2 = 7.5 min) dependent manner. Phorbol 12,13-dibutyrate increased cAMP levels by twofold and it potentiated the isoproterenol-induced cAMP formation. The biologically inactive phorbol ester, 4 alpha-phorbol had no effect. Staurosporine, a potent PKC inhibitor, inhibited phorbol 12,13-dibutyrate-induced cAMP formation in a dose-dependent manner (IC50 of 0.25 microM). The increase in cAMP levels by phorbol 12,13-dibutyrate results from stimulation of adenylate cyclase, rather than from inhibition of cAMP phosphodiesterase, and it is not mediated through Ca2+ mobilization. Pretreatment of the tissue with phorbol 12,13-dibutyrate inhibited IP3 production in response to PGF2 alpha. (B) Desensitization of the sphincter with PGF2 alpha for 45 min increased cAMP formation and attenuated IP3 production and contraction. The effects of PGF2 alpha desensitization were reversed by pretreatment of the tissue with staurosporine. Down-regulation of PKC prevented the PGF2 alpha-stimulated increase in cAMP formation. In the desensitized tissue, diacylglycerol, the endogenous activator of PKC, may arise from phosphatidylcholine, via phospholipase D. (A) Activation of PKC in the bovine iris sphincter leads to stimulation of adenylate cyclase and to an increase in cAMP formation. The cAMP formed inhibits IP3 production and muscle contraction. (B) PGF2 alpha desensitization results in adenylate cyclase activation, mediated through PKC. (C) PGF2 alpha desensitization could uncouple the receptor from the Gq and Gi proteins and enhance PG stimulation of adenylate cyclase activity through the Gs protein. (D) Uncoupling of the G proteins from the PG receptor and activation of PKC, both of which result in enhanced cAMP formation, may underlie the mechanism of PGF2 alpha desensitization. (E) These observations demonstrate "cross talk" between the two second messenger systems and their physiologic consequences.

Computer-assisted determination of minimum energy conformations. 7: A pharmacophore model of the active region of the alpha2-adrenoceptor

NASA Astrophysics Data System (ADS)

Ashman, William P.; Mickiewicz, A. P.; Nelson, Todd M.

1992-09-01

Molecular modeling and computational chemistry techniques are used to analyze compounds in developing pharmacophores of biological receptors to use as templates in structure activity relationship studies and to design new chemicals having physiological activity of interest. In this study, the results of x-ray crystal analyses and PM3 semi-empirical molecular orbital conformational analyses are used to determine the three-dimensional representations of selected adrenergic compounds known to be agonists with the alpha2-adrenoceptor in achieving optimized geometries and electrostatic parameters. The alpha2-adrenergic agonists interact with the adrenergic system receptors to produce various increases or decreases in hemodynamic responses (i.e., hypertension, hypotension, and bradycardia) and sedation. A pharmacophore model of the active region of the alpha2-adrenoceptor is described based on the superimposition of common structural, electrostatic, and physicochemical features of the compounds. Using the model to predict compound adrenergic activity and to design alpha2-adrenergic compounds is discussed.

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

Cazanave, Sophie; Vadrot, Nathalie; Tinel, Marina

Fas stimulation recruits neutrophils and activates macrophages that secrete tumor necrosis factor-{alpha} (TNF-{alpha}), which aggravates Fas-mediated liver injury. To determine whether nonsteroidal anti-inflammatory drugs modify these processes, we challenged 24-hour-fasted mice with the agonistic Jo2 anti-Fas antibody (4 {mu}g/mouse), and treated the animals 1 h later with saline or ibuprofen (250 mg/kg), a dual cyclooxygenase (COX)-1 and COX-2 inhibitor. Ibuprofen attenuated the Jo2-mediated recruitment/activation of myeloperoxidase-secreting neutrophils/macrophages in the liver, and attenuated the surge in serum TNF-{alpha}. Ibuprofen also minimized hepatic glutathione depletion, Bid truncation, caspase activation, outer mitochondrial membrane rupture, hepatocyte apoptosis and the increase in serum alanine aminotransferasemore » (ALT) activity 5 h after Jo2 administration, to finally decrease mouse mortality at later times. The concomitant administration of pentoxifylline (decreasing TNF-{alpha} secretion) and infliximab (trapping TNF-{alpha}) likewise attenuated the Jo2-mediated increase in TNF-{alpha}, the decrease in hepatic glutathione, and the increase in serum ALT activity 5 h after Jo2 administration. The concomitant administration of the COX-1 inhibitor, SC-560 (10 mg/kg) and the COX-2 inhibitor, celecoxib (40 mg/kg) 1 h after Jo2 administration, also decreased liver injury 5 h after Jo2 administration. In contrast, SC-560 (10 mg/kg) or celecoxib (40 or 160 mg/kg) given alone had no significant protective effects. In conclusion, secondary TNF-{alpha} secretion plays an important role in Jo2-mediated glutathione depletion and liver injury. The combined inhibition of COX-1 and COX-2 by ibuprofen attenuates TNF-{alpha} secretion, glutathione depletion, mitochondrial alterations, hepatic apoptosis and mortality in Jo2-treated fasted mice.« less

Antithrombin activities in childhood malnutrition.

PubMed Central

Jiménez, R A; Jiménez, E; Ingram, G I; Mora, L A; Atmetlla, F; Carrillo, J M; Vargas, W

1979-01-01

Antithrombin activities in 30 severely malnourished children and 40 normal children were estimated in clotting tests by thrombin neutralisation as anti-Xa and by a heparin antithrombin assay; and by immunodiffusion as alpha 2-globulin and alpha 1-antitrypsin. The patients' mean alpha 2-globulin was severely depressed, and there were less marked depletions in mean values for thrombin neutralisation, anti-Xa, and in the heparin antithrombin assay (which showed the flat curve thought to reflect a thrombotic tendency). The alpha 1-antitrypsin values were normal. The findings support the concept of antithrombin as the summation of alpha 2-globulin and alpha 1-antitrypsin (with alpha 2-macroglobulin); and the low values may be related to the high incidence of thrombosis reported in childhood malnutrition, although it was not seen in these patients. PMID:118190

In vitro inhibition activity of polyphenol-rich extracts from Syzygium aromaticum (L.) Merr. & Perry (Clove) buds against carbohydrate hydrolyzing enzymes linked to type 2 diabetes and Fe2+-induced lipid peroxidation in rat pancreas

PubMed Central

Adefegha, Stephen Adeniyi; Oboh, Ganiyu

2012-01-01

Objective To investigate and compare the inhibitory properties of free and bound phenolic extracts of clove bud against carbohydrate hydrolyzing enzymes (alpha-amylase & alpha-glucosidase) and Fe2+-induced lipid peroxidation in rat pancreas in vitro. Methods The free phenolics were extracted with 80% (v/v) acetone, while bound phenolics were extracted from the alkaline and acid hydrolyzed residue with ethyl acetate. Then, the interaction of the extracts with alpha-amylase and alpha-glucosidase was subsequently assessed. Thereafter, the total phenolic contents and antioxidant activities of the extracts were determined. Results The result revealed that both extracts inhibited alpha-amylase and alpha-glucosidase in a dose-dependent manner. However, the alpha-glucosidase inhibitory activity of the extracts were significantly (P<0.05) higher than their alpha-amylase inhibitory activity. The free phenolics (31.67 mg/g) and flavonoid (17.28 mg/g) contents were significantly (P<0.05) higher than bound phenolic (23.52 mg/g) and flavonoid (13.70 mg/g) contents. Both extracts also exhibited high antioxidant activities as typified by their high reducing power, 1,1 diphenyl-2- picrylhydrazyl (DPPH) and 2, 2-azinobis-3-ethylbenzo-thiazoline-6-sulfonate (ABTS) radical scavenging abilities, as well as inhibition of Fe2+-induced lipid peroxidation in rat pancreas in vitro. Conclusions This study provides a biochemical rationale by which clove elicits therapeutic effect on type 2 diabetes. PMID:23569846

Structure-based design of benzimidazole sugar conjugates: synthesis, SAR and in vivo anti-inflammatory and analgesic activities.

PubMed

El-Nezhawy, Ahmed O H; Gaballah, Samir T; Radwan, Mohamed A A; Baiuomy, Ayman R; Abdel-Salam, Omar M E

2009-11-01

A series of 2-methyl-N-substituted-benzimidazoles, bearing hydroxypyrrolidinon-5-yl or hydroxypyrrolidin-2-yl, 2,3:5,6-di-O-isopropylidene-alpha-D-mannofuranoside, 2,3,5,6-tetrahydroxy-alpha-D-mannofuranoside, 1:2,5:6-di-O-isopropylidene-alpha-D-gluco-furanose,3-O-benzyl-6,7-dideoxy-1:2-O-isopropylidene-alpha-D-xylo-heptofuranos-5-ulose, 3-O-benzyl-6,7-dideoxy-1,2-dihydroxy-alpha-D-xylo-heptofuranos-5-ulose, 1,2,5,6-tetrahydroxy-alpha-D-glucofuranose sugar moieties, were obtained in good yields from 2-methyl N-(trichloroacetamidomethyl)benzimidazole as a donor and carbohydrate residues as acceptor precursors in the presence of catalytic amount of trimethylsilyl trifluoromethanesulfonate (TMSOTf) as Lewis acid. Compounds 6, 7, 10, 13, 15, and 16 showed significant anti-inflammatory and analgesic activities.

Visceral and subcutaneous adipose tissue express and secrete functional alpha2hsglycoprotein (fetuin a) especially in obesity.

PubMed

Pérez-Sotelo, Diego; Roca-Rivada, Arturo; Larrosa-García, María; Castelao, Cecilia; Baamonde, Iván; Baltar, Javier; Crujeiras, Ana Belen; Seoane, Luisa María; Casanueva, Felipe F; Pardo, María

2017-02-01

The secretion of the hepatokine alpha-2-Heremans-Schmid glycoprotein/Fetuin A, implicated in pathological processes including systemic insulin resistance, by adipose tissue has been recently described. Thus, we have recently identified its presence in white adipose tissue secretomes by mass spectrometry. However, the secretion pattern and function of adipose-derived alpha-2-Heremans-Schmid glycoprotein are poorly understood. The aim of this study is to evaluate the expression and secretion of total and active phosphorylated alpha-2-Heremans-Schmid glycoprotein by adipose tissue from visceral and subcutaneous localizations in animals at different physiological and nutritional status including anorexia and obesity. Alpha-2-Heremans-Schmid glycoprotein expression and secretion in visceral adipose tissue and subcutaneous adipose tissue explants from animals under fasting and exercise training, at pathological situations such as anorexia and obesity, and from human obese individuals were assayed by immunoblotting, quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay. We reveal that visceral adipose tissue expresses and secretes more alpha-2-Heremans-Schmid glycoprotein than subcutaneous adipose tissue, and that this secretion is diminished after fasting and exercise training. Visceral adipose tissue from anorectic animals showed reduced alpha-2-Heremans-Schmid glycoprotein secretion; on the contrary, alpha-2-Heremans-Schmid glycoprotein is over-secreted by visceral adipose tissue in the occurrence of obesity. While secretion of active-PhophoSer321α2HSG by visceral adipose tissue is independent of body mass index, we found that the fraction of active-alpha-2-Heremans-Schmid glycoprotein secreted by subcutaneous adipose tissue increments significantly in situations of obesity. Functional studies show that the inhibition of adipose-derived alpha-2-Heremans-Schmid glycoprotein increases insulin sensitivity in differentiated adipocytes. In conclusion, visceral adipose tissue secretes more alpha-2-Heremans-Schmid glycoprotein than subcutaneous adipose tissue and this secretion is more sensitive to nutritional and physiological changes. The over-secretion of alpha-2-Heremans-Schmid glycoprotein by visceral adipose tissue, the increased secretion of the active phosphorylated form by subcutaneous adipose tissuein obese animals, and the adipose-derived alpha-2-Heremans-Schmid glycoprotein capacity to inhibit the insulin pathway suggest the participation of adipose-derived alpha-2-Heremans-Schmid glycoprotein in the deleterious effects of obesity.

Bovine alpha-lactalbumin stimulates mucus metabolism in gastric mucosa.

PubMed

Ushida, Y; Shimokawa, Y; Toida, T; Matsui, H; Takase, M

2007-02-01

Bovine alpha-lactalbumin (alpha-LA), a major milk protein, exerts strong gastroprotective activity against rat experimental gastric ulcers induced by ethanol or stress. To elucidate the mechanisms underlying this activity, the influence of alpha-LA on gastric mucus metabolism was investigated in vitro and in vivo. For the in vitro study, RGM1 cells (a rat gastric epithelial cell line) were selected for observation of the direct activity of alpha-LA on gastric mucosal cells and cultured in the presence of either alpha-LA or ovalbumin (OVA), a reference protein showing no gastroprotective activity. Amounts of synthesized and secreted mucin, a major component of mucus, were determined using [3H]glucosamine as a tracer, and prostaglandin E2 (PGE2) levels in the culture medium were determined by RIA. For the in vivo study, the thickness of the mucus gel layer, a protective barrier for gastric mucosa, was evaluated histochemically in rat gastric mucosa. alpha-Lactalbumin (3 mg/mL) significantly stimulated mucin synthesis and secretion in RGM1 cells and also increased PGE2 levels in the culture medium. In contrast, OVA showed no enhancing effects under identical conditions. Neither indomethacin, a cyclo-oxygenase inhibitor, nor AH23848, a prostaglandin EP4 receptor antagonist, affected alpha-LA-induced enhancement of mucin synthesis and secretion. In vivo, oral administration of alpha-LA (300 mg/kg x 3 times/d x 7 d) increased the thickness of the mucus gel layer in rats. These results indicate that alpha-LA fortifies the mucus gel layer by stimulating mucin production and secretion in gastric mucus-producing cells, and that this enhancing effect is independent of endogenous PGE2. Comparison of the efficacy of alpha-LA with OVA suggests that the activities observed in RGM1 cells are closely related to the gastroprotective effects in rat gastric ulcer models. In conclusion, alpha-LA stimulates mucus metabolism, and this action may be responsible for its gastroprotective activity.

Interconversion of the Specificities of Human Lysosomal Enzymes Associated with Fabry and Schindler Diseases

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

Tomasic, Ivan B.; Metcalf, Matthew C.; Guce, Abigail I.

2010-09-03

The human lysosomal enzymes {alpha}-galactosidase ({alpha}-GAL, EC 3.2.1.22) and {alpha}-N-acetylgalactosaminidase ({alpha}-NAGAL, EC 3.2.1.49) share 46% amino acid sequence identity and have similar folds. The active sites of the two enzymes share 11 of 13 amino acids, differing only where they interact with the 2-position of the substrates. Using a rational protein engineering approach, we interconverted the enzymatic specificity of {alpha}-GAL and {alpha}-NAGAL. The engineered {alpha}-GAL (which we call {alpha}-GALSA) retains the antigenicity of {alpha}-GAL but has acquired the enzymatic specificity of {alpha}-NAGAL. Conversely, the engineered {alpha}-NAGAL (which we call {alpha}-NAGAL{sup EL}) retains the antigenicity of {alpha}-NAGAL but has acquired themore » enzymatic specificity of the {alpha}-GAL enzyme. Comparison of the crystal structures of the designed enzyme {alpha}-GAL{sup SA} to the wild-type enzymes shows that active sites of {alpha}-GAL{sup SA} and {alpha}-NAGAL superimpose well, indicating success of the rational design. The designed enzymes might be useful as non-immunogenic alternatives in enzyme replacement therapy for treatment of lysosomal storage disorders such as Fabry disease.« less

Alpha1B-adrenoceptor signaling and cell motility: GTPase function of Gh/transglutaminase 2 inhibits cell migration through interaction with cytoplasmic tail of integrin alpha subunits.

PubMed

Kang, Sung Koo; Yi, Kye Sook; Kwon, Nyoun Soo; Park, Kwang-Hyun; Kim, Uh-Hyun; Baek, Kwang Jin; Im, Mie-Jae

2004-08-27

A multifunctional enzyme, G(h), is a GTP-binding protein that couples to the alpha(1B)-adrenoreceptor and stimulates phospholipase C-delta1 but also displays transglutaminase 2 (TG2) activity. G(h)/TG2 has been implicated to play a role in cell motility. In this study we have examined which function of G(h)/TG2 is involved in this cellular response and the molecular basis. Treatment of human aortic smooth muscle cell with epinephrine inhibits migration to fibronectin and vitronectin, and the inhibition is blocked by the alpha(1)-adrenoreceptor antagonist prazosin or chloroethylclonidine. Up-regulation or overexpression of G(h)/TG2 in human aortic smooth muscle cells, DDT1-MF2, or human embryonic kidney cells, HEK 293 cells, results in inhibition of the migratory activity, and stimulation of the alpha(1B)-adrenoreceptor with the alpha(1) agonist further augments the inhibition of migration of human aortic smooth muscle cells and DDT1-MF2. G(h)/TG2 is coimmunoprecipitated by an integrin alpha(5) antibody and binds to the cytoplasmic tail peptide of integrins alpha(5), alpha(v), and alpha(IIb) subunits in the presence of guanosine 5'-3-O-(thio)triphosphate (GTPgammaS). Mutation of Lys-Arg residues in the GFFKR motif, present in the alpha(5)-tail, significantly reduces the binding of GTPgammaS-G(h)/TG2. Moreover, the motif-containing integrin alpha(5)-tail peptides block G(h)/TG2 coimmunoprecipitation and reverse the inhibition of the migratory activity of HEK 293 cells caused by overexpression G(h)/TG2. These results provide evidence that G(h) function initiates the modulation of cell motility via association of GTP-bound G(h)/TG2 with the GFFKR motif located in integrin alpha subunits.

Peroxisome proliferator-activated receptor gamma coactivator-1 alpha acts as a tumor suppressor in hepatocellular carcinoma.

PubMed

Liu, Rui; Zhang, Haiyang; Zhang, Yan; Li, Shuang; Wang, Xinyi; Wang, Xia; Wang, Cheng; Liu, Bin; Zen, Ke; Zhang, Chen-Yu; Zhang, Chunni; Ba, Yi

2017-04-01

Peroxisome proliferator-activated receptor gamma coactivator-1 alpha plays a crucial role in regulating the biosynthesis of mitochondria, which is closely linked to the energy metabolism in various tumors. This study investigated the regulatory role of peroxisome proliferator-activated receptor gamma coactivator-1 alpha in the pathogenesis of hepatocellular carcinoma. In this study, the changes of peroxisome proliferator-activated receptor gamma coactivator-1 alpha messenger RNA levels between normal human liver and hepatocellular carcinoma tissue were examined by quantitative reverse transcription polymerase chain reaction. Knockdown of peroxisome proliferator-activated receptor gamma coactivator-1 alpha was conducted by RNA interference in the human liver cell line L02, while overexpression of peroxisome proliferator-activated receptor gamma coactivator-1 alpha was conducted by adenovirus encoding peroxisome proliferator-activated receptor gamma coactivator-1 alpha complementary DNA in the human hepatocarcinoma cell line HepG2. Cellular morphological changes were observed via optical and electron microscopy. Cellular apoptosis was determined by Hoechst 33258 staining. In addition, the expression levels of 21,400 genes in tissues and cells were detected by microarray. It was shown that peroxisome proliferator-activated receptor gamma coactivator-1 alpha expression was significantly downregulated in hepatocellular carcinoma compared with normal liver tissues. After knockdown of peroxisome proliferator-activated receptor gamma coactivator-1 alpha expression in L02 cells, cells reverted to immature and dedifferentiated morphology exhibiting cancerous tendency. Apoptosis occurred in the HepG2 cells after transfection by adenovirus encoding peroxisome proliferator-activated receptor gamma coactivator-1 alpha. Microarray analysis showed consistent results. The results suggest that peroxisome proliferator-activated receptor gamma coactivator-1 alpha acts as a tumor suppressor in the formation and development of hepatocellular carcinoma and that peroxisome proliferator-activated receptor gamma coactivator-1 alpha may be a potential therapeutic target for hepatocellular carcinoma.

Mitogen-activated protein kinase inhibitors suppress prostaglandin F(2alpha)-induced myosin-light chain phosphorylation and contraction in iris sphincter smooth muscle.

PubMed

Yousufzai, S Y; Gao, G; Abdel-Latif, A A

2000-10-27

The purpose of this study was to investigate the potential role of mitogen-activated protein (MAP) kinase in contraction by monitoring MAP kinase phosphorylation (activation) and contraction during agonist stimulation of cat iris sphincter smooth muscle. Changes in tension in response to prostaglandin F(2alpha), latanoprost, a prostaglandin F(2alpha) analog used as an anti-glaucoma drug, and carbachol were recorded isometrically, and MAP kinase activation was monitored by Western blot using a phosphospecific p42/p44 MAP kinase antibody. We found that treatment of the muscle with 2'-Amino-3'-methoxyflavone (PD98059) (10 microM), a specific inhibitor of MAP kinase kinase (MEK), inhibited significantly prostaglandin F(2alpha)- and latanoprost-induced phosphorylation and contraction, but had little effect on those evoked by carbachol. Prostaglandin F(2alpha) increased MAP kinase phosphorylation in a concentration-dependent manner with EC(50) value of 1.1 x 10(-8) M and increased contraction with EC(50) of 0.92 x 10(-9) M. The MAP kinase inhibitors PD98059, Apigenin and 1,4-Diamino-2,3-dicyano-1, 4bis(2-aminophenylthio)butadiene (UO126) inhibited prostaglandin F(2alpha)-induced contraction in a concentration-dependent manner with IC(50) values of 2.4, 3.0 and 4.8 microM, respectively. PD98059 had no effect on prostaglandin F(2alpha)- or on carbachol-stimulated inositol-1,4,5-trisphosphate (IP(3)) production. In contrast, the MAP kinase inhibitor inhibited prostaglandin F(2alpha)-induced myosin-light chain (MLC) phosphorylation, but had no effect on that of carbachol. N-[2-(N-(4-Chloro-cinnamyl)-N-methylaminomethyl)phenyl]-N-[2- hydroxyethyl]-4-methoxybenzenesulfonamide (KN-93) (10 microM), a Ca(2+)-calmodulin-dependent protein kinase inhibitor, and Wortmannin (10 microM), an MLC kinase inhibitor, inhibited significantly (by 80%) prostaglandin F(2alpha)- and carbachol-induced contraction. It can be concluded that in this smooth muscle p42/p44 MAP kinases are involved in the mechanism of prostaglandin F(2alpha)-, but not in that of carbachol, induced contraction. In addition, these data clearly indicate that the stimulation of the iris sphincter with prostaglandin F(2alpha) and carbachol activate two distinct pathways, the MAP kinase pathway and the Ca(2+) mobilization pathway.

ATRX induction by mutant huntingtin via Cdx2 modulates heterochromatin condensation and pathology in Huntington's disease

PubMed Central

Lee, J; Hong, Y K; Jeon, G S; Hwang, Y J; Kim, K Y; Seong, K H; Jung, M-K; Picketts, D J; Kowall, N W; Cho, K S; Ryu, H

2012-01-01

Aberrant chromatin remodeling is involved in the pathogenesis of Huntington's disease (HD) but the mechanism is not known. Herein, we report that mutant huntingtin (mtHtt) induces the transcription of alpha thalassemia/mental retardation X linked (ATRX), an ATPase/helicase and SWI/SNF-like chromatin remodeling protein via Cdx-2 activation. ATRX expression was elevated in both a cell line model and transgenic model of HD, and Cdx-2 occupancy of the ATRX promoter was increased in HD. Induction of ATRX expanded the size of promyelocytic leukemia nuclear body (PML-NB) and increased trimethylation of H3K9 (H3K9me3) and condensation of pericentromeric heterochromatin, while knockdown of ATRX decreased PML-NB and H3K9me3 levels. Knockdown of ATRX/dXNP improved the hatch rate of fly embryos expressing mtHtt (Q127). ATRX/dXNP overexpression exacerbated eye degeneration of eye-specific mtHtt (Q127) expressing flies. Our findings suggest that transcriptional alteration of ATRX by mtHtt is involved in pericentromeric heterochromatin condensation and contributes to the pathogenesis of HD. PMID:22240898

The relationship between physical activity and 2-hydroxyestrone, 16alpha-hydroxyestrone, and the 2/16 ratio in premenopausal women (United States).

PubMed

Bentz, Ann T; Schneider, Carole M; Westerlind, Kim C

2005-05-01

Estrogen is metabolized in the body through two mutually exclusive pathways yielding metabolites with different biological activities: the low estrogenic 2-hydroxyestrone (2-OHE1) and the highly estrogenic 16alpha-hydroxyestrone (16alpha-OHE1). The ratio of these metabolites (2/16) may be predictive of risk for developing breast cancer. Early evidence has demonstrated that exercise may alter estrogen metabolism to favor the weak estrogen, 2-OHE1. Seventy-seven eumenorrheic females completed physical activity logs for two weeks prior to providing a luteal phase urine sample. Concentrations of 2-OHE1 and 16alpha-OHE1 were measured and the 2/16 ratio computed. Hierarchical regression, controlling for age and body mass index (BMI), was used to determine relationships between estrogen metabolites and daily physical activity. Regression analyses indicated significant positive relationships between physical activity and 2-OHE1 and the 2/16 ratio (p < 0.05) that appears to be independent of BMI. 16alpha-OHE1 was not significantly related to physical activity. These results indicate that physical activity may modulate estrogen metabolism to favor the weak estrogen, 2-OHE1, thus producing a higher 2/16 ratio. This alteration in estrogen metabolism may represent one of the mechanisms by which increased physical activity reduces breast cancer risk.

Mutagenesis of the C2 domain of protein kinase C-alpha. Differential roles of Ca2+ ligands and membrane binding residues.

PubMed

Medkova, M; Cho, W

1998-07-10

The C2 domains of conventional protein kinase C (PKC) have been implicated in their Ca2+-dependent membrane binding. The C2 domain of PKC-alpha contains several Ca2+ ligands that bind multiple Ca2+ ions and other putative membrane binding residues. To understand the roles of individual Ca2+ ligands and protein-bound Ca2+ ions in the membrane binding and activation of PKC-alpha, we mutated five putative Ca2+ ligands (D187N, D193N, D246N, D248N, and D254N) and measured the effects of mutations on vesicle binding, enzyme activity, and monolayer penetration of PKC-alpha. Altered properties of these mutants indicate that individual Ca2+ ions and their ligands have different roles in the membrane binding and activation of PKC-alpha. The binding of Ca2+ to Asp187, Asp193, and Asp246 of PKC-alpha is important for the initial binding of protein to membrane surfaces. On the other hand, the binding of another Ca2+ to Asp187, Asp246, Asp248, and Asp254 induces the conformational change of PKC-alpha, which in turn triggers its membrane penetration and activation. Among these Ca2+ ligands, Asp246 was shown to be most essential for both membrane binding and activation of PKC-alpha, presumably due to its coordination to multiple Ca2+ ions. Furthermore, to identify the residues in the C2 domain that are involved in membrane binding of PKC-alpha, we mutated four putative membrane binding residues (Trp245, Trp247, Arg249, and Arg252). Membrane binding and enzymatic properties of two double-site mutants (W245A/W247A and R249A/R252A) indicate that Arg249 and Arg252 are involved in electrostatic interactions of PKC-alpha with anionic membranes, whereas Trp245 and Trp247 participate in its penetration into membranes and resulting hydrophobic interactions. Taken together, these studies provide the first experimental evidence for the role of C2 domain of conventional PKC as a membrane docking unit as well as a module that triggers conformational changes to activate the protein.

Effects of prostaglandin F(2alpha)and carbachol on MAP kinases, cytosolic phospholipase A(2)and arachidonic acid release in cat iris sphincter smooth muscle cells.

PubMed

Husain, S; Abdel-Latif, A A

2001-05-01

The signal transduction pathways initiated by Ca(2+)-mobilizing agonists, such as prostaglandin F(2alpha)(PGF(2alpha)) and carbachol (CCh), leading to activation of cytosolic phospholipase A(2)(cPLA(2)) and arachidonic acid (AA) release in a wide variety of tissues remain obscure. To further define the role of protein kinases in receptor mediated stimulation of cPLA(2)and consequently AA release we have investigated the role of mitogen-activated protein (MAP) kinases and protein kinase C (PKC) in PGF(2alpha)- and CCh-induced cPLA(2)phosphorylation and AA release in cat iris sphincter smooth muscle (CISM) cells. The cells were prelabeled with [(3)H]AA for 24 hr and incubated in the absence or presence of the agonist for 5-10 min as indicated. MAP kinases activities and cPLA(2)phosphorylation were determined in immunoprecipitates obtained by using anti-p38 MAP kinase and anti-cPLA(2)antibodies. We found that: (a) PGF(2alpha)and CCh increased p38 MAP kinase activity by 197 and 215%, respectively, and increased p42/p44 MAP kinase activity by 200 and 125%, respectively. (b) SB202190, a p38 MAP kinase specific inhibitor, inhibited PGF(2alpha)- and CCh-induced cPLA(2)phosphorylation by 92 and 85%, respectively, and AA release by 62 and 78%, respectively. (c) PD98059, a p42/p44 MAP kinase inhibitor, inhibited CCh-induced cPLA(2)phosphorylation by 70% and AA release by 71%, but had no effect on that of PGF(2alpha). (d) Inhibition of PKC activity by RO 31-8220 inhibited both PGF(2alpha)- and CCh-stimulation of p38 MAP kinase, p42/p44 MAP kinases and cPLA(2)phosphorylation. We conclude from these results that in CISM cells PGF(2alpha)-induced cPLA(2)phosphorylation and AA release is mediated through p38 MAP kinase, but not through p42/p44 MAP kinases, whereas that of CCh is mediated through both p38 MAP kinase and p42/p44 MAP kinases. These effects of PGF(2alpha)and CCh are regulated by the MAP kinases in a PKC-dependent manner. Studies aimed at elucidating the role of protein kinases in the coupling mechanism between the activation of PGF(2alpha)and muscarinic receptors, and the stimulation of cPLA(2)and AA release in the smooth muscles of the iris-ciliary body will provide important information about the role of protein kinases signaling pathways in smooth muscle function, as well as about the mechanism of the intraocular pressure-lowering effects of PGF(2alpha)and its analog, latanoprost, in glaucoma therapy. Copyright 2001 Academic Press.

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

Szymanska, Ewelina; Korzeniowski, Marek; Raynal, Patrick

Receptor Fc{gamma}IIA (Fc{gamma}RIIA) associates with plasma membrane rafts upon activation to trigger signaling cascades leading to actin polymerization. We examined whether compartmentalization of PI(4,5)P{sub 2} and PI(4,5)P{sub 2}-synthesizing PIP5-kinase I{alpha} to rafts contributes to Fc{gamma}RIIA signaling. A fraction of PIP5-kinase I{alpha} was detected in raft-originating detergent-resistant membranes (DRM) isolated from U937 monocytes and other cells. The DRM of U937 monocytes contained also a major fraction of PI(4,5)P{sub 2}. PIP5-kinase I{alpha} bound PI(4,5)P{sub 2}, and depletion of the lipid displaced PIP5-kinase I{alpha} from the DRM. Activation of Fc{gamma}RIIA in BHK transfectants led to recruitment of the kinase to the plasma membranemore » and enrichment of DRM in PI(4,5)P{sub 2}. Immunofluorescence studies revealed that in resting cells the kinase was associated with the plasma membrane, cytoplasmic vesicles and the nucleus. After Fc{gamma}RIIA activation, PIP5-kinase I{alpha} and PI(4,5)P{sub 2} co-localized transiently with the activated receptor at distinct cellular locations. Immunoelectron microscopy studies revealed that PIP5-kinase I{alpha} and PI(4,5)P{sub 2} were present at the edges of electron-dense assemblies containing activated Fc{gamma}RIIA in their core. The data suggest that activation of Fc{gamma}RIIA leads to membrane rafts coalescing into signaling platforms containing PIP5-kinase I{alpha} and PI(4,5)P{sub 2}.« less

Alpha-lactalbumin unfolding is not sufficient to cause apoptosis, but is required for the conversion to HAMLET (human alpha-lactalbumin made lethal to tumor cells).

PubMed

Svensson, Malin; Fast, Jonas; Mossberg, Ann-Kristin; Düringer, Caroline; Gustafsson, Lotta; Hallgren, Oskar; Brooks, Charles L; Berliner, Lawrence; Linse, Sara; Svanborg, Catharina

2003-12-01

HAMLET (human alpha-lactalbumin made lethal to tumor cells) is a complex of human alpha-lactalbumin and oleic acid (C18:1:9 cis) that kills tumor cells by an apoptosis-like mechanism. Previous studies have shown that a conformational change is required to form HAMLET from alpha-lactalbumin, and that a partially unfolded conformation is maintained in the HAMLET complex. This study examined if unfolding of alpha-lactalbumin is sufficient to induce cell death. We used the bovine alpha-lactalbumin Ca(2+) site mutant D87A, which is unable to bind Ca(2+), and thus remains partially unfolded regardless of solvent conditions. The D87A mutant protein was found to be inactive in the apoptosis assay, but could readily be converted to a HAMLET-like complex in the presence of oleic acid. BAMLET (bovine alpha-lactalbumin made lethal to tumor cells) and D87A-BAMLET complexes were both able to kill tumor cells. This activity was independent of the Ca(2+)site, as HAMLET maintained a high affinity for Ca(2+) but D87A-BAMLET was active with no Ca(2+) bound. We conclude that partial unfolding of alpha-lactalbumin is necessary but not sufficient to trigger cell death, and that the activity of HAMLET is defined both by the protein and the lipid cofactor. Furthermore, a functional Ca(2+)-binding site is not required for conversion of alpha-lactalbumin to the active complex or to cause cell death. This suggests that the lipid cofactor stabilizes the altered fold without interfering with the Ca(2+)site.

Management of acute exacerbations of chronic obstructive pulmonary disease (COPD). Guidelines from the Société de pneumologie de langue française (summary).

PubMed

Jouneau, S; Dres, M; Guerder, A; Bele, N; Bellocq, A; Bernady, A; Berne, G; Bourdin, A; Brinchault, G; Burgel, P R; Carlier, N; Chabot, F; Chavaillon, J M; Cittee, J; Claessens, Y E; Delclaux, B; Deslée, G; Ferré, A; Gacouin, A; Girault, C; Ghasarossian, C; Gouilly, P; Gut-Gobert, C; Gonzalez-Bermejo, J; Jebrak, G; Le Guillou, F; Léveiller, G; Lorenzo, A; Mal, H; Molinari, N; Morel, H; Morel, V; Noel, F; Pégliasco, H; Perotin, J M; Piquet, J; Pontier, S; Rabbat, A; Revest, M; Reychler, G; Stelianides, S; Surpas, P; Tattevin, P; Roche, N

2017-04-01

Chronic obstructive pulmonary disease (COPD) is the chronic respiratory disease with the most important burden on public health in terms of morbidity, mortality and health costs. For patients, COPD is a major source of disability because of dyspnea, restriction in daily activities, exacerbation, risk of chronic respiratory failure and extra-respiratory systemic organ disorders. The previous French Language Respiratory Society (SPLF) guidelines on COPD exacerbations were published in 2003. Using the GRADE methodology, the present document reviews the current knowledge on COPD exacerbation through 4 specific outlines: (1) epidemiology, (2) clinical evaluation, (3) therapeutic management and (4) prevention. Specific aspects of outpatients and inpatients care are discussed, especially regarding assessment of exacerbation severity and pharmacological approach. Copyright © 2017 SPLF. Published by Elsevier Masson SAS. All rights reserved.

Actions of alpha2 adrenoceptor ligands at alpha2A and 5-HT1A receptors: the antagonist, atipamezole, and the agonist, dexmedetomidine, are highly selective for alpha2A adrenoceptors.

PubMed

Newman-Tancredi, A; Nicolas, J P; Audinot, V; Gavaudan, S; Verrièle, L; Touzard, M; Chaput, C; Richard, N; Millan, M J

1998-08-01

This study examined the activity of chemically diverse alpha2 adrenoceptor ligands at recombinant human (h) and native rat (r) alpha2A adrenoceptors compared with 5-HT1A receptors. First, in competition binding experiments at h alpha2A and h5-HT1A receptors expressed in CHO cells, several compounds, including the antagonists 1-(2-pyrimidinyl)piperazine (1-PP), (+/-)-idazoxan, benalfocin (SKF 86466), yohimbine and RX 821,002, displayed preference for h alpha2A versus h5-HT1A receptors of only 1.4-, 3.6-, 4-, 10- and 11-fold, respectively (based on differences in pKi values). Clonidine, brimonidine (UK 14304), the benzopyrrolidine fluparoxan and the guanidines guanfacine and guanabenz exhibited intermediate selectivity (22- to 31-fold) for h alpha2A receptors. Only the antagonist atipamezole and the agonist dexmedetomidine (DMT) displayed high preference for alpha2 adrenoceptors (1290- and 91-fold, respectively). Second, the compounds were tested for their ability to induce h5-HT1A receptor-mediated G-protein activation, as indicated by the stimulation of [35S]GTPgammaS binding. All except atipamezole and RX 821,002 exhibited agonist activity, with potencies which correlated with their affinity for h5-HT1A receptors. Relative efficacies (Emax values) were 25-35% for guanabenz, guanfacine, WB 4101 and benalfocin, 50-65% for 1-PP, (+/-)-idazoxan and clonidine, and over 70% for fluparoxan, oxymetazoline and yohimbine (relative to 5-HT = 100%). Yohimbine-induced [35S]GTPgammaS binding was inhibited by the selective 5-HT1A receptor antagonist WAY 100,635. In contrast, RX 821,002 was the only ligand which exhibited antagonist activity at h5-HT1A receptors, inhibiting 5-HT-stimulated [35S]GTPgammaS binding. Atipamezole, which exhibited negligeable affinity for 5-HT1A receptors, was inactive. Third, the affinities for r alpha2A differed considerably from the affinities for h alpha2A receptors whereas the affinities for r5-HT1A differed much less from the affinities for h5-HT1A receptors. This affected markedly the affinity ratios of certain compounds. For example, (+/-)-idazoxan was only 3.6-fold selective for h alpha2A versus h5-HT1A but 51-fold selective for r alpha2A versus r5-HT1A receptors. Conversely, yohimbine was tenfold selective for h alpha2A versus h5-HT1A adrenoceptors but 4.2-fold selective for r alpha2A versus r5-HT1A receptors. Nevertheless, both atipamezole and DMT were highly selective for both rat and human alpha2A versus rat or human 5-HT1A receptors. In conclusion, these data indicate that: (1) the agonist DMT and the antagonist atipamezole are the ligands of choice to distinguish alpha2-mediated from 5-HT1A-mediated actions, whilst several of the other compounds show only low or modest selectivity for alpha2A over 5-HT1A receptors; (2) caution should be exercised in experimental and clinical interpretation of the actions of traditionally employed alpha2 ligands, such as clonidine, yohimbine and (+/-)-idazoxan, which exhibit marked agonist activity at 5-HT1A receptors.

AtFXG1, an Arabidopsis gene encoding alpha-L-fucosidase active against fucosylated xyloglucan oligosaccharides.

PubMed

de La Torre, Francisco; Sampedro, Javier; Zarra, Ignacio; Revilla, Gloria

2002-01-01

An alpha-L-fucosidase (EC 3.2.1.51) able to release the t-fucosyl residue from the side chain of xyloglucan oligosaccharides has been detected in the leaves of Arabidopsis plants. Moreover, an alpha-L-fucosidase with similar substrate specificity was purified from cabbage (Brassica oleracea) leaves to render a single band on SDS-PAGE. Two peptide sequences were obtained from this protein band, and they were used to identify an Arabidopsis gene coding for an alpha-fucosidase that we propose to call AtFXG1. In addition, an Arabidopsis gene with homology with known alpha-L-fucosidases has been also found, and we proposed to name it as AtFUC1. Both AtFXG1 and ATFUC1 were heterologously expressed in Pichia pastoris cells and the alpha-L-fucosidase activities secreted to the culture medium. The alpha-L-fucosidase encoded by AtFXG1 was active against the oligosaccharides from xyloglucan XXFG as well as against 2'-fucosyl-lactitol but not against p-nitrophenyl-alpha-L-fucopyranoside. However, the AtFUC1 heterologously expressed was active only against 2'-fucosyl-lactitol. Thus, the former must be related to xyloglucan metabolism.

Alpha-2-Macroglobulin Is Acutely Sensitive to Freezing and Lyophilization: Implications for Structural and Functional Studies

PubMed Central

Wyatt, Amy R.; Kumita, Janet R.; Farrawell, Natalie E.; Dobson, Christopher M.; Wilson, Mark R.

2015-01-01

Alpha-2-macroglobulin is an abundant secreted protein that is of particular interest because of its diverse ligand binding profile and multifunctional nature, which includes roles as a protease inhibitor and as a molecular chaperone. The activities of alpha-2-macroglobulin are typically dependent on whether its conformation is native or transformed (i.e. adopts a more compact conformation after interactions with proteases or small nucleophiles), and are also influenced by dissociation of the native alpha-2-macroglobulin tetramer into stable dimers. Alpha-2-macroglobulin is predominately present as the native tetramer in vivo; once purified from human blood plasma, however, alpha-2-macroglobulin can undergo a number of conformational changes during storage, including transformation, aggregation or dissociation. We demonstrate that, particularly in the presence of sodium chloride or amine containing compounds, freezing and/or lyophilization of alpha-2-macroglobulin induces conformational changes with functional consequences. These conformational changes in alpha-2-macroglobulin are not always detected by standard native polyacrylamide gel electrophoresis, but can be measured using bisANS fluorescence assays. Increased surface hydrophobicity of alpha-2-macroglobulin, as assessed by bisANS fluorescence measurements, is accompanied by (i) reduced trypsin binding activity, (ii) increased chaperone activity, and (iii) increased binding to the surfaces of SH-SY5Y neurons, in part, via lipoprotein receptors. We show that sucrose (but not glycine) effectively protects native alpha-2-macroglobulin from denaturation during freezing and/or lyophilization, thereby providing a reproducible method for the handling and long-term storage of this protein. PMID:26103636

Ovine cardiac Na,K-ATPase: isolation by means of selective solubilization in Lubrol and the effect of 1 alpha,2 alpha-epoxyscillirosidin on this enzyme.

PubMed

Venter, P A; Naudé, R J; Oelofsen, W; Swan, G E

1997-01-01

The inhibition of cardiac Na,K-ATPase by 1 alpha,2 alpha-epoxyscillirosidin is the principal cause of poisoning of cattle by the tulip, Homeria pallida. The ultimate goals of this study were to study the interaction between 1 alpha,2 alpha-epoxyscillirosidin and ovine Na,K-ATPase by means of inhibition and displacement binding studies. Ovine cardiac Na,K-ATPase was isolated in membrane-bound form by means of deoxycholate treatment, high-speed ultracentrifugation, NaI treatment and selective solubilization in Lubrol. The inhibition of ovine cardiac and commercial porcine cerebral cortex Na,K-ATPase by 1 alpha,2 alpha-epoxyscilirosidin and ouabain was studied using a discontinuous Na,K-ATPase assay. The binding of 1 alpha,2 alpha-epoxyscillirosidin, ouabain and digoxin to the above enzymes was compared using a displacement binding assay with [3H] oubain. The Lubrol-solubilized ovine cardiac Na,K-ATPase showed a specific activity of 0.3 U/mg with no ouabain insensitive activity. I50 values of 2.1 x 10(-8) and 2.7 x 10(-8) were obtained for the inhibition of this enzyme by 1 alpha,2 alpha-epoxyscillirosidin and ouabain, respectively. 1 alpha,2 alpha-Epoxyscillirosidin has a much higher KD value (1.5 x 10(-7) M), however, than ouabain (9.5 x 10(-9) M) and digoxin (1.7 x 10(-8) M) in displacement binding studies with [3H]ouabain. 1 alpha,2 alpha-Epoxyscillirosidin is a potent inhibitor of ovine cardiac Na,K-ATPase and is a slightly stronger inhibitor of the enzyme than ouabain. The anomalous result for the displacement of 1 alpha,2 alpha-epoxyscillirosidin from its receptor is either a result of different affinities that K+ has for the enzyme ouabain and enzyme-1 alpha,2 alpha-epoxyscillirosidin complexes or because of different complex stabilities of these complexes.

Calcium signaling in brain mitochondria: interplay of malate aspartate NADH shuttle and calcium uniporter/mitochondrial dehydrogenase pathways.

PubMed

Contreras, Laura; Satrústegui, Jorgina

2009-03-13

Ca2+ signaling in mitochondria has been mainly attributed to Ca2+ entry to the matrix through the Ca2+ uniporter and activation of mitochondrial matrix dehydrogenases. However, mitochondria can also sense increases in cytosolic Ca2+ through a mechanism that involves the aspartate-glutamate carriers, extramitochondrial Ca2+ activation of the NADH malate-aspartate shuttle (MAS). Both pathways are linked through the shared substrate alpha-ketoglutarate (alphaKG). Here we have studied the interplay between the two pathways under conditions of Ca2+ activation. We show that alphaKG becomes limiting when Ca2+ enters in brain or heart mitochondria, but not liver mitochondria, resulting in a drop in alphaKG efflux through the oxoglutarate carrier and in a drop in MAS activity. Inhibition of alphaKG efflux and MAS activity by matrix Ca2+ in brain mitochondria was fully reversible upon Ca2+ efflux. Because of their differences in cytosolic calcium concentration requirements, the MAS and Ca2+ uniporter-mitochondrial dehydrogenase pathways are probably sequentially activated during a Ca2+ transient, and the inhibition of MAS at the center of the transient may provide an explanation for part of the increase in lactate observed in the stimulated brain in vivo.

P2X7-regulated protection from exacerbations and loss of control is independent of asthma maintenance therapy.

PubMed

Denlinger, Loren C; Manthei, David M; Seibold, Max A; Ahn, Kwangmi; Bleecker, Eugene; Boushey, Homer A; Calhoun, William J; Castro, Mario; Chinchili, Vernon M; Fahy, John V; Hawkins, Greg A; Icitovic, Nicolina; Israel, Elliot; Jarjour, Nizar N; King, Tonya; Kraft, Monica; Lazarus, Stephen C; Lehman, Erik; Martin, Richard J; Meyers, Deborah A; Peters, Stephen P; Sheerar, Dagna; Shi, Lei; Sutherland, E Rand; Szefler, Stanley J; Wechsler, Michael E; Sorkness, Christine A; Lemanske, Robert F

2013-01-01

The function of the P2X(7) nucleotide receptor protects against exacerbation in people with mild-intermittent asthma during viral illnesses, but the impact of disease severity and maintenance therapy has not been studied. To evaluate the association between P2X(7), asthma exacerbations, and incomplete symptom control in a more diverse population. A matched P2RX7 genetic case-control was performed with samples from Asthma Clinical Research Network trial participants enrolled before July 2006, and P2X(7) pore activity was determined in whole blood samples as an ancillary study to two trials completed subsequently. A total of 187 exacerbations were studied in 742 subjects, and the change in asthma symptom burden was studied in an additional 110 subjects during a trial of inhaled corticosteroids (ICS) dose optimization. African American carriers of the minor G allele of the rs2230911 loss-of-function single nucleotide polymorphism were more likely to have a history of prednisone use in the previous 12 months, with adjustment for ICS and long-acting β(2)-agonists use (odds ratio, 2.7; 95% confidence interval, 1.2-6.2; P = 0.018). Despite medium-dose ICS, attenuated pore function predicted earlier exacerbations in incompletely controlled patients with moderate asthma (hazard ratio, 3.2; confidence interval, 1.1-9.3; P = 0.033). After establishing control with low-dose ICS in patients with mild asthma, those with attenuated pore function had more asthma symptoms, rescue albuterol use, and FEV(1) reversal (P < 0.001, 0.03, and 0.03, respectively) during the ICS adjustment phase. P2X(7) pore function protects against exacerbations of asthma and loss of control, independent of baseline severity and the maintenance therapy.

SH2 domains of the p85 alpha subunit of phosphatidylinositol 3-kinase regulate binding to growth factor receptors.

PubMed Central

McGlade, C J; Ellis, C; Reedijk, M; Anderson, D; Mbamalu, G; Reith, A D; Panayotou, G; End, P; Bernstein, A; Kazlauskas, A

1992-01-01

The binding of cytoplasmic signaling proteins such as phospholipase C-gamma 1 and Ras GTPase-activating protein to autophosphorylated growth factor receptors is directed by their noncatalytic Src homology region 2 (SH2) domains. The p85 alpha regulatory subunit of phosphatidylinositol (PI) 3-kinase, which associates with several receptor protein-tyrosine kinases, also contains two SH2 domains. Both p85 alpha SH2 domains, when expressed individually as fusion proteins in bacteria, bound stably to the activated beta receptor for platelet-derived growth factor (PDGF). Complex formation required PDGF stimulation and was dependent on receptor tyrosine kinase activity. The bacterial p85 alpha SH2 domains recognized activated beta PDGF receptor which had been immobilized on a filter, indicating that SH2 domains contact autophosphorylated receptors directly. Several receptor tyrosine kinases within the PDGF receptor subfamily, including the colony-stimulating factor 1 receptor and the Steel factor receptor (Kit), also associate with PI 3-kinase in vivo. Bacterially expressed SH2 domains derived from the p85 alpha subunit of PI 3-kinase bound in vitro to the activated colony-stimulating factor 1 receptor and to Kit. We infer that the SH2 domains of p85 alpha bind to high-affinity sites on these receptors, whose creation is dependent on receptor autophosphorylation. The SH2 domains of p85 are therefore primarily responsible for the binding of PI 3-kinase to activated growth factor receptors. Images PMID:1372092

Transcriptional regulation by retinoic acid of interleukin-2 alpha receptors in human B cells.

PubMed Central

Bhatti, L; Sidell, N

1994-01-01

In this study, we demonstrated that retinoic acid (RA) up-regulated interleukin-2 receptor-alpha (IL-2R alpha) expression on two human B-cell lines, IE8.6 and SKW6.4. Deleted forms of the human IL-2R alpha promoter linked to the bacterial chloramphenicol acetyltransferase reporter gene were transfected into IE8.6 cells in order to define RA-responsive regulatory domains. Experiments using the -1.6 kb construct, which contains all known regulatory regions in the IL-2R alpha promoter, indicated that RA could induce IL-2R alpha promoter activity. The basal activity of the -471 construct was initially low, but was markedly enhanced by the addition of RA. Deletion of promoter sequences between -471 and -317 resulted in a significant augmentation of basal promoter activity and abolished promoter induction by RA. This finding revealed a requirement for sequences 5' of base -317 for RA-induced promoter activation, raising the possibility of the presence of both a RA response element and a negative regulatory element (NRE) upstream of base -317. Transfection studies with internal deletion mutants with the putative NRE removed resulted in increases in basal promoter activity and unresponsiveness to RA similar to the -317 construct. In contrast, an internal deletion mutant with the NRE intact had low basal activity and was inducible by RA similar to the -471 construct. Taken together, our results suggested that RA-induced activation of the IL-2R alpha promoter was through changes in the function of a NRE present between bases -400 and -368. This 31-base pair element may interact with an adjacent RA-responsive regulatory site as well as being responsible for down-regulation of basal IL-2R alpha expression under certain conditions. Images Figure 3 Figure 4 Figure 5 Figure 6 PMID:8157276

Alpha 2-adrenergic receptor stimulation of phospholipase A2 and of adenylate cyclase in transfected Chinese hamster ovary cells is mediated by different mechanisms

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

Jones, S.B.; Halenda, S.P.; Bylund, D.B.

1991-02-01

The effect of alpha 2-adrenergic receptor activation on adenylate cyclase activity in Chinese hamster ovary cells stably transfected with the alpha 2A-adrenergic receptor gene is biphasic. At lower concentrations of epinephrine forskolin-stimulated cyclic AMP production is inhibited, but at higher concentrations the inhibition is reversed. Both of these effects are blocked by the alpha 2 antagonist yohimbine but not by the alpha 1 antagonist prazosin. Pretreatment with pertussis toxin attenuates inhibition at lower concentrations of epinephrine and greatly potentiates forskolin-stimulated cyclic AMP production at higher concentrations of epinephrine. alpha 2-Adrenergic receptor stimulation also causes arachidonic acid mobilization, presumably via phospholipasemore » A2. This effect is blocked by yohimbine, quinacrine, removal of extracellular Ca2+, and pretreatment with pertussis toxin. Quinacrine and removal of extracellular Ca2+, in contrast, have no effect on the enhanced forskolin-stimulated cyclic AMP production. Thus, it appears that the alpha 2-adrenergic receptor in these cells can simultaneously activate distinct signal transduction systems; inhibition of adenylate cyclase and stimulation of phospholipase A2, both via G1, and potentiation of cyclic AMP production by a different (pertussis toxin-insensitive) mechanism.« less

Synthesis and biological evaluation of 2-heteroarylthioalkanoic acid analogues of clofibric acid as peroxisome proliferator-activated receptor alpha agonists.

PubMed

Giampietro, Letizia; Ammazzalorso, Alessandra; Giancristofaro, Antonella; Lannutti, Fabio; Bettoni, Giancarlo; De Filippis, Barbara; Fantacuzzi, Marialuigia; Maccallini, Cristina; Petruzzelli, Michele; Morgano, Annalisa; Moschetta, Antonio; Amoroso, Rosa

2009-10-22

A series of 2-heteroarylthioalkanoic acids were synthesized through systematic structural modifications of clofibric acid and evaluated for human peroxisome proliferator-activated receptor alpha (PPARalpha) transactivation activity, with the aim of obtaining new hypolipidemic compounds. Some thiophene and benzothiazole derivatives showing a good activation of the receptor alpha were screened for activity against the PPARgamma isoform. The gene induction of selected compounds was also investigated in the human hepatoma cell line.

Stimulation of H(2)O(2) generation by calcium in brain mitochondria respiring on alpha-glycerophosphate.

PubMed

Tretter, Laszlo; Takacs, Katalin; Kövér, Kinga; Adam-Vizi, Vera

2007-11-15

It has been reported recently (Tretter et al., 2007b) that in isolated guinea pig brain mitochondria supported by alpha-glycerophosphate (alpha-GP) reactive oxygen species (ROS) are produced through the reverse electron transport (RET) in the respiratory chain and by alpha-glycerophosphate dehydrogenase (alpha-GPDH). We studied the effect of calcium on the generation of H(2)O(2) as measured by the Amplex Red fluorescent assay in this model. H(2)O(2) production in alpha-GP-supported mitochondria was increased significantly in the presence of 100, 250, and 500 nM Ca(2+), respectively. In addition, Ca(2+) enhanced the membrane potential, the rate of oxygen consumption, and the NAD(P)H autofluorescence in these mitochondria. Direct measurement of alpha-GPDH activity showed that Ca(2+) stimulated the enzyme by decreasing the Km for alpha-GP. In those mitochondria where RET was eliminated by the Complex I inhibitor rotenone (2 microM) or due to depolarization by ADP (1 mM), the rate of H(2)O(2) formation was smaller and the stimulation of H(2)O(2) generation by Ca(2+) was prevented partly, but the stimulatory effect of Ca(2+) was still significant. These data indicate that in alpha-GP-supported mitochondria activation of alpha-GPDH by Ca(2+) leads to an accelerated RET-mediated ROS generation as well as to a stimulated ROS production by alpha-GPDH.

Analysis of PGC-1{alpha} variants Gly482Ser and Thr612Met concerning their PPAR{gamma}2-coactivation function

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

Nitz, Inke; Ewert, Agnes; Klapper, Maja

2007-02-09

Peroxisome proliferator-activated receptor-{gamma} coactivator-1{alpha} (PGC-1{alpha}) is a cofactor involved in adaptive thermogenesis, fatty acid oxidation, and gluconeogenesis. Dysfunctions of this protein are likely to contribute to the development of obesity and the metabolic syndrome. This is in part but not definitely confirmed by results of population studies. The aim of this study was to investigate if common genetic variants rs8192678 (Gly482Ser) and rs3736265 (Thr612Met) in the PGC-1{alpha} gene lead to a functional consequence in cofactor activity using peroxisome proliferator-activated receptor-{gamma} 2 (PPAR{gamma}2) as interacting transcription factor. Reporter gene assays in HepG2 cells with wildtype and mutant proteins of both PGC1{alpha}more » and PPAR{gamma}2 (Pro12Ala, rs1801282) using the acyl-CoA-binding protein (ACBP) promoter showed no difference in coactivator activity. This is First study implicating that the Gly482Ser and Thr612Met polymorphisms in PGC-1{alpha} and Pro12Ala polymorphism in PPAR{gamma}2 do not affect the functional integrity of these proteins.« less

Chronic stress exacerbates neuropathic pain via the integration of stress-affect-related information with nociceptive information in the central nucleus of the amygdala.

PubMed

Li, Ming-Jia; Liu, Ling-Yu; Chen, Lin; Cai, Jie; Wan, You; Xing, Guo-Gang

2017-04-01

Exacerbation of pain by chronic stress and comorbidity of pain with stress-related psychiatric disorders, including anxiety and depression, represent significant clinical challenges. However, the underlying mechanisms still remain unclear. Here, we investigated whether chronic forced swim stress (CFSS)-induced exacerbation of neuropathic pain is mediated by the integration of stress-affect-related information with nociceptive information in the central nucleus of the amygdala (CeA). We first demonstrated that CFSS indeed produces both depressive-like behaviors and exacerbation of spared nerve injury (SNI)-induced mechanical allodynia in rats. Moreover, we revealed that CFSS induces both sensitization of basolateral amygdala (BLA) neurons and augmentation of long-term potentiation (LTP) at the BLA-CeA synapse and meanwhile, exaggerates both SNI-induced sensitization of CeA neurons and LTP at the parabrachial (PB)-CeA synapse. In addition, we discovered that CFSS elevates SNI-induced functional up-regulation of GluN2B-containing NMDA (GluN2B-NMDA) receptors in the CeA, which is proved to be necessary for CFSS-induced augmentation of LTP at the PB-CeA synapse and exacerbation of pain hypersensitivity in SNI rats. Suppression of CFSS-elicited depressive-like behaviors by antidepressants imipramine or ifenprodil inhibits the CFSS-induced exacerbation of neuropathic pain. Collectively, our findings suggest that CFSS potentiates synaptic efficiency of the BLA-CeA pathway, leading to the activation of GluN2B-NMDA receptors and sensitization of CeA neurons, which subsequently facilitate pain-related synaptic plasticity of the PB-CeA pathway, thereby exacerbating SNI-induced neuropathic pain. We conclude that chronic stress exacerbates neuropathic pain via the integration of stress-affect-related information with nociceptive information in the CeA.

Determining the diagnostic value of endogenous carbon monoxide in chronic obstructive pulmonary disease exacerbations.

PubMed

Dogan, Nurettin Özgür; Corbacioglu, Seref Kerem; Bildik, Fikret; Kilicaslan, Isa; Günaydin, Gül Pamukcu; Cevik, Yunsur; Ülker, Volkan; Hakoglu, Onur; Gökcen, Emre

2014-09-01

To determine whether endogenous carbon monoxide levels in exacerbations of Chronic Obstructive Pulmonary Disease patients were higher compared to healthy individuals and to investigate alteration of carbon monoxide levels across the three different severity stages of Global Initiative for Chronic Obstructive Lung Disease criteria related to Chronic Obstructive Pulmonary Disease exacerbations. The prospective study was conducted from January to March 2011 at two medical institutions in Ankara, Turkey, and comprised patients of acute Chronic Obstructive Pulmonary Disease exacerbations. The severity of the exacerbations was based on the Global Initiative for Chronic Obstructive Lung Disease criteria. Patients with active tobacco smoking, suspicious carbon monoxide poisoning and uncertain diagnosis were excluded. healthy control subjects who did not have any comorbid diseases and smoking habitus were also enrolled to compare the differences between carboxyhaemoglobin levels A two-tailed Mann-Whitney U test with Bonferroni correction was done following a Kruskal-Wallis test for statistical purposes. There were 90 patients and 81 controls in the study. Carboxyhaemoglobin levels were higher in the patients than the controls (p < 0.001). As for the three severity stages, Group 1 had a median carboxyhaemoglobin of 1.6 (0.95- 2.00). The corresponding levels in Group 2 (1.8 [1.38-2.20]) and Group 3 (1.9 [1.5-3.0]) were higher than the controls (p < 0.001 and p < 0.005 respectively). No statistically significant difference between Group 1 and the controls (1.30 [1.10-1.55]) was observed (p < 0.434). Carboxyhaemoglobin levels were significantly higher in exacerbations compared with the normal population. Also, in more serious exacerbations, carboxyhaemoglobin levels were significantly increased compared with healthy individuals and mild exacerbations.

Continuous extraovular administration of prostaglandin F2alpha for midtrimester abortion.

PubMed

Lauersen, N H; Wilson, K H

1974-09-15

Midtrimester abortion was successfully induced in 74 of 76 patients by a continuous extraovular administration of (PGF2alpha) prostaglandin F2alpha via a constant-infusion pump. 2 patients in the 13th-14th weeks of gestation failed to abort despite good uterine activity. The mean abortion time for successful inductions was 16.21 hours. Parous patients aborted somewhat faster than nulliparous patients, but the difference was not statistically significant. All patients were monitored throughout the abortion procedure, and uterine activity was calculated and analyzed. Uterine activity developed within 15 minutes of PGF2alpha instillation and showed the characteristic uterine response to PGs with a sharp rise in intrauterine tonus. The gastrointestinal side effects in this series were much less than those reported for intraamniotic instillation of PG, and there was good patient tolerance of the procedure. The main complication of extraovular administration of PGF2alpha for midtrimester abortion was endometritis, which occurred in 7 patients. The patients who developed endometritis had, as a group, longer abortion times (mean=28 hours). 3 patients with severe preeclampsia and intrauterine death in the third trimester also had successfully induced labor with extraovular administration of PGF2alpha. The method of PGF2alpha administration in the series was found to have a high success rate, good patient tolerance, and fewer side effects than when abortion was induced by intraamniotic instillation of PGF2alpha.

alpha-Galactosidase from Bacillus megaterium VHM1 and its application in removal of flatulence-causing factors from soymilk.

PubMed

Patil, Aravind Goud G; K, Praveen Kumar S; Mulimani, Veerappa H; Veeranagouda, Yaligara; Lee, Kyoung

2010-11-01

A bacterial strain capable of producing extracellular alpha-galactosidase was isolated from sugar cane industrial waste soil sample. Microbiological, physiological, and biochemical studies revealed that isolate belonged to Bacillus sp,. Furthermore, 16S rDNA sequence analysis of new isolates was identified as Bacillus megaterium VHM1. The production of alpha-galactosidase was optimized by various physical culture conditions. Guar gum and yeast extract acted as the best carbon and nitrogen source, respectively for the production of alpha-galactosidase. The enzyme showed an optimum pH at 7.5 and was stable over a pH between 5 and 9. The enzyme was optimally active in 55degreesC and the enzyme was thermostable with half life of 120 minutes at 55 degrees C and lost their 90%, residual activity in 120 minutes at 60 degrees C. alpha-Galactosidase was strongly inhibited by Ag2, Cu2, and Hg2+ at 1mM concentration. The metal ions Fe2, Mn2+, and Mg2+ had no effect on alpha-galactosidase activity, Zn2+,Ni2+, and Ca2+ reduced the enzyme activity slightly. The B megaterium VHM1 enzyme treatment completely hydrolyzed flatulence-causing sugars of soymilk within one and half hour.

Transmembrane Na+ and Ca2+ electrochemical gradients in cardiac muscle and their relationship to force development

PubMed Central

1982-01-01

Na+- and CA2+-sensitive microelectrodes were used to measure intracellular Na+ and Ca2+ activities (alpha iCa) of sheep ventricular muscle and Purkinje strands to study the interrelationship between Na+ and Ca2+ electrochemical gradients (delta muNa and delta muCa) under various conditions. In ventricular muscle, alpha iNa was 6.4 +/- 1.2 mM and alpha iCa was 87 +/- 20 nM ([Ca/+] = 272 nM). A graded decrease of external Na+ activity (alpha oNa) resulted in decrease of alpha iNa, and increase of alpha iCa. There was increase of twitch tension in low- alpha oNa solutions, and occasional increase of resting tension in 40% alpha oNa. Increase of external Ca2+ (alpha oCa) resulted in increase of alpha iCa and decrease of alpha iNa. Decrease of alpha oCa resulted in decrease of alpha iCa and increase of alpha iNa. The apparent resting Na-Ca energy ratio (delta muCa/delta muNa) was between 2.43 and 2.63. When the membrane potential (Vm) was depolarized by 50 mM K+ in ventricular muscle, Vm depolarized by 50 mV, alpha iNa decreased, and alpha iCa increased, with the development of a contracture. The apparent energy coupling ratio did not change with depolarization. 5 x 10(-6) M ouabain induced a large increase in alpha iNa ad alpha iCa, accompanied by an increase in twitch and resting tension. Under the conditions we have studied, delta muNa and delta muCa appeared to be coupled and n was nearly constant at 2.5, as would be expected if the Na-Ca exchange system was able to set the steady level of alpha iCa. Tension threshold was about 230 nM alpha iCa. The magnitude of twitch tension was directly related to alpha iCa. PMID:6292328

[Nebulized budesonide in the treatment of exacerbations of chronic obstructive pulmonary disease: Efficacy, safety, and effects on the serum levels of soluble differentiation molecules].

PubMed

Makarova, E V; Varvarina, G N; Menkov, N V; Czapaeva, M Yu; Lazareva, E S; Kazatskaya, Zh A; Novikov, V V; Karaulov, A V

2016-01-01

To investigate the efficacy and safety of nebulized budesonide and systemic glucocorticosteroids (GCS) (SGCS) in the treatment of an exacerbation of chronic obstructive pulmonary disease (COPD) and their effects on the serum concentration of soluble leukocyte differentiation antigens. Seventy-eight hospitalized patients with an acute exacerbation of COPD were randomized into two groups: 1) 37 patients took nebulized budesonide 4 mg/day; 2) 41 patients received intravenous prednisolone. The symptoms of COPD, forced expiratory volume in one second (FEV1) and other spirometric indicators, peripheral blood oxygen saturation (SpO2), and adverse events were studied. The serum levels of the soluble adhesion molecules CD50 (sCD50) and CD54 (sCD54) and the lymphocyte activation molecules CD38 (sCD38) and CD25 (sCD25) were investigated by an enzyme immunoassay. There was a significant resolution of the symptoms of COPD, FEV1, and SpO2 in both groups after treatment. The incidence of hyperglycemia episodes was lower in the budesonide group than in the sGCS group. GCSs caused a decrease in the serum level of soluble interleukin-2 receptor (sCD25) in both groups. A prednisolone cycle, unlike a budesonide one, was found to reduce the concentrations of sCD54, sCD50, and sCD38. Nebulized budesonide is an effective and safe alternative to SGCS in treating an exacerbation of COPD. Inhaled GCSs, unlike SGCSs, exhibit anti-inflammatory activity, but exert no immunosuppressive activity.

Cystathionine β-Synthase Inhibition Is a Potential Therapeutic Approach to Treatment of Ischemic Injury

PubMed Central

Chan, Su Jing; Chai, Chou; Lim, Tze Wei; Yamamoto, Mie; Lo, Eng H; Lai, Mitchell Kim Peng

2015-01-01

Hydrogen sulfide (H2S) has been reported to exacerbate stroke outcome in experimental models. Cystathionine β-synthase (CBS) has been implicated as the predominant H2S-producing enzyme in central nervous system. When SH-SY5Y cells were transfected to overexpress CBS, these cells were able to synthesize H2S when exposed to high levels of enzyme substrates but not substrate concentrations that may reflect normal physiological conditions. At the same time, these cells demonstrated exacerbated cell death when subjected to oxygen and glucose deprivation (OGD) together with high substrate concentrations, indicating that H2S production has a detrimental effect on cell survival. This effect could be abolished by CBS inhibition. The same effect was observed with primary astrocytes exposed to OGD and high substrates or sodium hydrosulfide. In addition, CBS was upregulated and activated by truncation in primary astrocytes subjected to OGD. When rats were subjected to permanent middle cerebral artery occlusion, CBS activation was also observed. These results imply that in acute ischemic conditions, CBS is upregulated and activated by truncation causing an increased production of H2S, which exacerbate the ischemic injuries. Therefore, CBS inhibition may be a viable approach to stroke treatment. PMID:25873304

Macrophage Migration Inhibitory Factor Deletion Exacerbates Pressure Overload-Induced Cardiac Hypertrophy through Mitigating Autophagy

PubMed Central

Xu, Xihui; Hua, Yinan; Nair, Sreejayan; Bucala, Richard; Ren, Jun

2014-01-01

The proinflammatory cytokine macrophage migration inhibitory factor (MIF) has been shown to be cardioprotective in various pathological conditions. However, the underlying mechanisms still remain elusive. In this study, we revealed that MIF deficiency overtly exacerbated abdominal aorta constriction (AAC)-induced cardiac hypertrophy and contractile anomalies. MIF deficiency interrupted myocardial autophagy in hypertrophied hearts. Rapamycin administration mitigated the exacerbated hypertrophic responses in MIF−/− mice. Using the phenylephrine-induced hypertrophy in vitro model in H9C2 myoblasts, we confirmed that MIF governed activation of AMPK-mTOR-autophagy cascade. Confocal microscopic examination demonstrated that MIF depletion prevented phenylephrine-induced mitophagy in H9C2 myoblasts. Myocardial Parkin, an E3 ubiquitin ligase and a marker for mitophagy, was significantly upregulated following sustained pressure overload, the effect of which was prevented by MIF knockout. Moreover, our data exhibited that levels of MIF, AMPK activation and autophagy were elevated concurrently in human failing hearts. These data indicate that endogenous MIF regulates the mTOR signaling to activate autophagy to preserve cardiac geometry and protect against hypertrophic responses. PMID:24366076

Validation of a Quality of Life Questionnaire for Bronchiectasis: psychometric analyses of the Spanish QOL-B-V3.0.

PubMed

Olveira, Casilda; Olveira, Gabriel; Espildora, Francisco; Giron, Rosa-Maria; Muñoz, Gerard; Quittner, Alexandra L; Martinez-Garcia, Miguel-Angel

2014-05-01

Bronchiectasis is a chronic disease, leading to worsening of health-related quality of life. This study evaluated the psychometric properties of a new patient-reported outcome for non-cystic fibrosis bronchiectasis, the Quality of Life Questionnaire Bronchiectasis, translated into Spanish (QOL-B-Sp-V3.0). This prospective study recruited clinically stable patients with non-cystic fibrosis bronchiectasis at 4 Spanish centers. Health status was assessed with multiple indicators (dyspnea, exacerbations, bronchorrhea, etc.), microbiological, radiological, spirometric, and anthropometric parameters plus St-George Respiratory Questionnaire (SGRQ). Psychometric analyses included internal consistency, test-retest reliability, convergent validity, predictive validity, and responsivity to change. The 207 stable patients (mean age 57.2 years) had a Bhalla score of 11.53 ± 7.39 and FEV1% of 68.3 ± 22.2 %. One hundred and sixty-one stable patients repeated the test 2 weeks later, and 80 patients who had an exacerbation within 6 months of the assessment also repeated it. Internal consistency was high across all scales (Cronbach's alpha >0.70). Thirty-six of 37 items correlated more strongly with their assigned scale than a competing scale. Test-retest coefficients were strong (intraclass correlations r = 0.68-0.88). All scales, except Treatment Burden, discriminated significantly between patients with mild, moderate, and severe disease according to FEV1% and other respiratory parameters. Strong convergence was found between the QOL-B-Sp-V3.0 and SGRQ. Significant correlations were found between QOL-B-Sp-V3.0 and various clinical, spirometric, radiological, and anthropometric variables. Significant differences were found on all QOL-B-Sp-V3.0 scales, except emotional functioning, between the baseline responses and onset of an exacerbation; robust sensitivity to change was observed on the Respiratory Symptoms scale. The QOL-B-Sp-V3.0 questionnaire demonstrated strong reliability and validity. Scores were reproducible after 2 weeks, and it discriminated between patients who varied in severity and was responsive to changes related to exacerbation.

SM22{alpha}-induced activation of p16{sup INK4a}/retinoblastoma pathway promotes cellular senescence caused by a subclinical dose of {gamma}-radiation and doxorubicin in HepG2 cells

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

Kim, Tae Rim; Lee, Hee Min; Lee, So Yong

Research highlights: {yields} SM22{alpha} overexpression in HepG2 cells leads cells to a growth arrest state, and the treatment of a subclinical dose of {gamma}-radiation or doxorubicin promotes cellular senescence. {yields} SM22{alpha} overexpression elevates p16{sup INK4a} followed by pRB activation, but there are no effects on p53/p21{sup WAF1/Cip1} pathway. {yields} SM22{alpha}-induced MT-1G activates p16{sup INK4a}/pRB pathway, which promotes cellular senescence by damaging agents. -- Abstract: Smooth muscle protein 22-alpha (SM22{alpha}) is known as a transformation- and shape change-sensitive actin cross-linking protein found in smooth muscle tissue and fibroblasts; however, its functional role remains uncertain. We reported previously that SM22{alpha} overexpression confersmore » resistance against anti-cancer drugs or radiation via induction of metallothionein (MT) isozymes in HepG2 cells. In this study, we demonstrate that SM22{alpha} overexpression leads cells to a growth arrest state and promotes cellular senescence caused by treatment with a subclinical dose of {gamma}-radiation (0.05 and 0.1 Gy) or doxorubicin (0.01 and 0.05 {mu}g/ml), compared to control cells. Senescence growth arrest is known to be controlled by p53 phosphorylation/p21{sup WAF1/Cip1} induction or p16{sup INK4a}/retinoblastoma protein (pRB) activation. SM22{alpha} overexpression in HepG2 cells elevated p16{sup INK4a} followed by pRB activation, but did not activate the p53/p21{sup WAF1/Cip1} pathway. Moreover, MT-1G, which is induced by SM22{alpha} overexpression, was involved in the activation of the p16{sup INK4a}/pRB pathway, which led to a growth arrest state and promoted cellular senescence caused by damaging agents. Our findings provide the first demonstration that SM22{alpha} modulates cellular senescence caused by damaging agents via regulation of the p16{sup INK4a}/pRB pathway in HepG2 cells and that these effects of SM22{alpha} are partially mediated by MT-1G.« less

Tumor cell alpha-N-acetylgalactosaminidase activity and its involvement in GcMAF-related macrophage activation.

PubMed

Mohamad, Saharuddin B; Nagasawa, Hideko; Uto, Yoshihiro; Hori, Hitoshi

2002-05-01

Alpha-N-acetyl galactosaminidase (alpha-NaGalase) has been reported to accumulate in serum of cancer patients and be responsible for deglycosylation of Gc protein, which is a precursor of GcMAF-mediated macrophage activation cascade, finally leading to immunosuppression in advanced cancer patients. We studied the biochemical characterization of alpha-NaGalase from several human tumor cell lines. We also examined its effect on the potency of GcMAF to activate mouse peritoneal macrophage to produce superoxide in GcMAF-mediated macrophage activation cascade. The specific activity of alpha-NaGalases from human colon tumor cell line HCT116, human hepatoma cell line HepG2, and normal human liver cells (Chang liver cell line) were evaluated using two types of substrates; GalNAc-alpha-PNP (exo-type substrate) and Gal-beta-GalNAc-alpha-PNP (endo-type substrate). Tumor-derived alpha-NaGalase having higher activity than normal alpha-NaGalase, had higher substrate specificity to the exo-type substrate than to the endo-type substrate, and still maintained its activity at pH 7. GcMAF enhance superoxide production in mouse macrophage, and pre-treatment of GcMAF with tumor cell lysate reduce the activity. We conclude that tumor-derived alpha-NaGalase is different in biochemical characterization compared to normal alpha-NaGalase from normal Chang liver cells. In addition, tumor cell-derived alpha-NaGalase decreases the potency of GcMAF on macrophage activation.

17{alpha}-Estradiol arrests cell cycle progression at G{sub 2}/M and induces apoptotic cell death in human acute leukemia Jurkat T cells

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

Jun, Do Youn; Park, Hae Sun; Kim, Jun Seok

2008-09-15

A pharmacological dose (2.5-10 {mu}M) of 17{alpha}-estradiol (17{alpha}-E{sub 2}) exerted a cytotoxic effect on human leukemias Jurkat T and U937 cells, which was not suppressed by the estrogen receptor (ER) antagonist ICI 182,780. Along with cytotoxicity in Jurkat T cells, several apoptotic events including mitochondrial cytochrome c release, activation of caspase-9, -3, and -8, PARP degradation, and DNA fragmentation were induced. The cytotoxicity of 17{alpha}-E{sub 2} was not blocked by the anti-Fas neutralizing antibody ZB-4. While undergoing apoptosis, there was a remarkable accumulation of G{sub 2}/M cells with the upregulatoin of cdc2 kinase activity, which was reflected in the Thr56more » phosphorylation of Bcl-2. Dephosphorylation at Tyr15 and phosphorylation at Thr161 of cdc2, and significant increase in the cyclin B1 level were underlying factors for the cdc2 kinase activation. Whereas the 17{alpha}-E{sub 2}-induced apoptosis was completely abrogated by overexpression of Bcl-2 or by pretreatment with the pan-caspase inhibitor z-VAD-fmk, the accumulation of G{sub 2}/M cells significantly increased. The caspase-8 inhibitor z-IETD-fmk failed to influence 17{alpha}-E{sub 2}-mediated caspase-9 activation, but it markedly reduced caspase-3 activation and PARP degradation with the suppression of apoptosis, indicating the contribution of caspase-8; not as an upstream event of the mitochondrial cytochrome c release, but to caspase-3 activation. In the presence of hydroxyurea, which blocked the cell cycle progression at the G{sub 1}/S boundary, 17{alpha}-E{sub 2} failed to induce the G{sub 2}/M arrest as well as apoptosis. These results demonstrate that the cytotoxicity of 17{alpha}-E{sub 2} toward Jurkat T cells is attributable to apoptosis mainly induced in G{sub 2}/M-arrested cells, in an ER-independent manner, via a mitochondria-dependent caspase pathway regulated by Bcl-2.« less

EEG alpha activity and hallucinatory experience during sensory deprivation.

PubMed

Hayashi, M; Morikawa, T; Hori, T

1992-10-01

The relationship between hallucinatory experiences under sensory deprivation and EEG alpha activities was studied. Each of seven male students lived alone in an air conditioned, soundproof dark room for 72 hours. When hallucinatory experiences occurred, the students pressed a button at once. If they could not press the button during the experience, they were required to press it two times when the hallucinatory experience was finished. Spectral analysis was performed on the consecutive EEG samples from just before button-presses to 10 min. before them, and the average alpha band amplitudes were obtained for the four epochs (0-.5, .5-2, 2-5, 5-10 min.). For the single button-presses, the amplitude of alpha band increased 2 min. before the button-presses. Right-hemisphere EEG activation was observed in the occipital area for the double button-presses. The results suggest an association between the hallucinatory experiences under sensory deprivation and the amount of EEG alpha activity.

COPD Exacerbation and Cholinesterase Therapy in Dementia Patients.

PubMed

Mahan, Rebecca J; Blaszczyk, Amie Taggart

2016-04-01

Chronic obstructive pulmonary disease (COPD) is a nonreversible inflammatory condition of the lungs. Acetylcholine is a neurotransmitter involved in autonomic regulation of the airways, resulting in bronchoconstriction and mucous production. Cholinesterase inhibitors (ChEIs), a cornerstone therapy of dementia treatment, increase acetylcholine. Theoretically, ChEI use in patients with COPD can place patients at increased risk of exacerbation secondary to increased acetylcholine activity. A retrospective chart review was performed comparing veterans with dementia and COPD who received ChEIs with those who did not at the Veterans Affairs North Texas Health Care System. Frequency of exacerbation in the first 90 days following ChEI initiation was compared. Secondary outcomes assessed exacerbation severity and a potential protective effect of inhaled anticholinergics. A total of 94 patients were eligible for the study; 52 received a ChEI and 42 did not. The risk of exacerbation over 90 days was higher in the ChEI users with 10 (19%) experiencing an exacerbation compared with 3 (7%) in the nonusers (P = 0.133), showing a clinically significant trend. Of the patients experiencing an exacerbation, 2 patients on ChEIs had multiple exacerbations over the 90 days. The use of inhaled anticholinergics was not found to decrease the risk of exacerbation. The use of ChEIs may increase the risk of COPD exacerbation in the first 90 days of therapy in patients with dementia and COPD. This finding is clinically significant as previous studies have indicated no risk.

[Factors associated with the quality of life in patients with chronic obstructive pulmonary disease].

PubMed

Villar Balboa, Iván; Carrillo Muñoz, Ricard; Regí Bosque, Meritxell; Marzo Castillejo, Mercè; Arcusa Villacampa, Núria; Segundo Yagüe, Marta

2014-04-01

To describe the relationship between individual or combined prognostic factors in the multidimensional classifications (BODE and ADO), and health-related quality of life (HRQOL) in patients with chronic obstructive pulmonary disease (COPD). Cross-sectional descriptive study. Primary care. Systematic random sample of 102 patients diagnosed with COPD, excluding those patients with acute exacerbation, dementia, terminal illness or those who receive home care. Demographics variables, smoking habits, body mass index and number of exacerbations. Comorbidity. Degree of dyspnea. Respiratory function tests. Exercise capacity. The BODE index and the ADO index. The EuroQol-5D questionnaire (EQ-5D), and visual analogue scale (VAS). EQ-5D: mobility: 43.9%; personal care: 13.3%; daily-life activities: 29.6%; pain/discomfort: 55.1%; anxiety/depression: 37.8%, and 34.7% VAS ≤ 60%. Exacerbations: Mobility, OR: 1.85 (95%CI: 1.08-3.20); personal care, OR: 2.12 (95%CI: 1.3-4.76); daily-life activities, OR: 2.35 (95%CI: 1.17-4.71); VAS, regression coefficient: -3.50 (95%CI: 6.31- -0.70). Dyspnea: mobility, OR: 4.47 (95%CI: 1.39-14.42); daily-life activities, OR: 7.71 (95%CI: 2.03-12.34); VAS, regression coefficient: -7.15 (95%CI: 11.71- -2.59). BODE: mobility, OR: 1.53 (95%CI: 1.15-2.02); personal care, OR: 2.08 (95%CI: 1.40-3.11); daily-life activities, OR: 1.97 (95%CI: 1.38-2.80); VAS, regression coefficient: -3.96 (95%CI: -5.51- -2.42). ADO: mobility, OR: 2.42 (95%CI: 1.39-4.20); personal care, OR: 3.21 (95%CI: 1.67-6.18); daily-life activities, OR: 3.17 (95%CI: 1.69-5.93); VAS, regression coefficient: -3.53 (95%CI: -5.57- -1.49). The BODE index and the ADO index showed a significant association with HRQOL. Exacerbations and dyspnea were the best individual factors related to HRQoL. Copyright © 2013 Elsevier España, S.L. All rights reserved.

The effect of early-life stress and chronic high-sucrose diet on metabolic outcomes in female rats.

PubMed

Maniam, Jayanthi; Antoniadis, Christopher P; Morris, Margaret J

2015-01-01

Early-life stress affects metabolic outcomes and choice of diet influences the development of metabolic disease. Here we tested the hypothesis that chronic sugar intake exacerbates metabolic deficits induced by early-life stress. Early-life stress was induced in Sprague-Dawley rats using limited nesting material in early lactation (LN, postnatal days 2-9), and siblings were given chow alone or with additional sucrose post weaning (n = 9-17 per group). Female control and LN siblings had unlimited access to either chow plus water, or chow and water plus 25% sucrose solution (Sucrose), from 3-15 weeks of age. Weekly body weight and food intake were measured. Glucose and insulin tolerance were tested at 13 and 14 weeks of age, respectively. Rats were killed at 15 weeks. Hepatic triglyceride and markers of lipid synthesis - fatty acid synthase, acetyl-CoA carboxylase alpha and oxidation - and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (Pgc-1α) were examined. Mediators of hepatic glucocorticoid metabolism, specifically 11-beta hydroxysteroid dehydrogenase-1 (11βHSD-1), 5-α reductase, and glucocorticoid and mineralocorticoid receptor mRNAs were also measured. Sucrose increased caloric intake in both groups, but overall energy intake was not altered by LN exposure. LN exposure had no further impact on sucrose-induced glucose intolerance and increased plasma and liver triglycerides. Hepatic markers of fat synthesis and oxidation were concomitantly activated and 11βHSD-1 mRNA expression was increased by 53% in LN-Sucrose versus Con-Sucrose rats. Adiposity was increased by 26% in LN-Sucrose versus Con-Sucrose rats. Thus, LN exposure had minimal adverse metabolic effects despite high-sugar diet postweaning.

Effect of pregnant mare's serum gonadotrophin on the activities of delta 4-5 alpha-reductase, aromatase, and other enzymes in the ovaries of immature rats.

PubMed

Suzuki, K; Kawakura, K; Tamaoki, B I

1978-05-01

After incubation of progesterone, 17 alpha-hydroxyprogesterone, androstenedione, and testostrone with an ovarian preparation (supernatant fluid at 10,000 x g) of immature rats (21-23 days of age) in the presence of NADPH, 3 alpha- and 3 beta-hydroxy-5 alpha-reduced steroids were obtained as the major metabolites. Among the enzyme activities relevant to the metabolism, delta 4-5 alpha-reductase and 3 beta-hydroxysteroid dehydrogenase were intracellularly localized to the microsomal fraction (10,000--105,000 x g), and 3 alpha-hydroxysteroid dehydrogenase was detected exclusively in the cytosol fraction (supernatant fluid at 105,000 x g). Within 2 days after a single injection of pregnant mare's serum gonadotrophin (10 IU/rat) to 21-day-old female rats, the following occurred: 1) an enhancement of 17 alpha-hydroxylase and C-17-C-20 lyase activities; 2) a suppression of delta 4-5 alpha-reductase activity; and 3) an increase in aromatizing activity. From the above-mentioned results, it was concluded that the increased secretion of estrogen from ovaries of immature rats stimulated by pregnant mare's serum gonadotrophin administration was caused by a modification of the ovarian enzyme activities relevant to estrogen production.

N-acetylcysteine attenuates TNF-alpha-induced p38 MAP kinase activation and p38 MAP kinase-mediated IL-8 production by human pulmonary vascular endothelial cells.

PubMed

Hashimoto, S; Gon, Y; Matsumoto, K; Takeshita, I; Horie, T

2001-01-01

1. We have previously shown that tumour necrosis factor-alpha (TNF-alpha) activates p38 mitogen-activated protein (MAP) kinase to produce interleukin-8 (IL-8) by human pulmonary vascular endothelial cells. Reactive oxygen species (ROS) including H(2)O(2) generated by TNF-alpha can act as signalling intermediates for cytokine induction; therefore, scavenging ROS by anti-oxidants is important for the regulation of cytokine production. However, the effect of N-acetylcysteine (NAC), which acts as a precursor of glutathione (GSH) synthesis, on TNF-alpha-induced activation of p38 MAP kinase pathway and p38 MAP kinase-mediated IL-8 production by human pulmonary vascular endothelial cells has not been determined. To clarify these issues, we examined the effect of NAC on TNF-alpha-induced activation of p38 MAP kinase, MAP kinase kinase (MKK) 3 and MKK6 which are upstream regulators of p38 MAP kinase, and p38 MAP kinase-mediated IL-8 production. 2. Human pulmonary vascular endothelial cells that had been preincubated with NAC were stimulated with TNF-alpha and then the activation of p38 MAP kinase and MKK3/MKK6 in the cells and IL-8 concentrations in the culture supernatants were determined. 3. Intracellular GSH levels increased in NAC-treated cells. 4. NAC attenuated TNF-alpha-induced activation of p38 MAP kinase and MKK3/MKK6. 5. NAC attenuated p38 MAP kinase-mediated IL-8 production by TNF-alpha-stimulated cells. 6. These results indicate that the cellular reduction and oxidation (redox) regulated by intracellular GSH is critical for TNF-alpha-induced activation of p38 MAP kinase pathway and p38 MAP kinase-mediated IL-8 production by human pulmonary vascular endothelial cells, and we emphasize that anti-oxidant therapy is an important strategy for the treatment of acute lung injury.

Independent modulation of the activity of alpha-ketoglutarate dehydrogenase complex by Ca2+ and Mg2+.

PubMed

Panov, A; Scarpa, A

1996-01-16

The activity of alpha-ketoglutarate dehydrogenase complex (KGDHC), an important enzyme regulating several metabolic pathways, could be regulated by changes in the environment within the mitochondrial matrix. It has been postulated that the activity of this and other dehydrogenases in vivo could be modulated by changes in the intramitochondrial concentrations of Ca2+ or Mg2+. Using a purified alpha-ketoglutarate dehydrogenase from pig hearts, the effect of Ca2+ and/or Mg2+ on the enzyme activity was investigated. Either Ca2+ or Mg2+ increased enzyme activity, and the effects were additive if the concentrations of free divalent cations were below 0.1 and 1 mM for Ca2+ and Mg2+, respectively. In the presence of 1 mM alpha-ketoglutarate and other cofactors, the KM for Mg2+ was 25 microM and less than 1 microM for Ca2+. The KM for alpha-ketoglutarate was a function of the divalent cation(s) present: 4 +/- 1.1 mM in the absence of Ca2+, with or without Mg2+; 2.2 mM in the presence of 1.8 microM Ca2+ alone; and 0.3 mM in the presence of both Ca2+ and Mg2+. Mg2+ increased KGDHC activity only in the presence of thiamine pyrophosphate (TPP) indicating that KGDHC requires both TPP and Mg2+ for enzyme's maximal activity. The affinity of KGDHC for NAD+ is significantly changed by either Mg2+ or Ca2+. The conclusions are that changes in both Ca2+ and Mg2+, in concentrations possibly occurring within mitochondria, could control KGDHC activity and that thiamine pyrophosphate is required for maximal enzyme activity.

Involvement of Sp1 elements in the promoter activity of genes affected in keratoconus.

PubMed

Maruyama, Y; Wang, X; Li, Y; Sugar, J; Yue, B Y

2001-08-01

Keratoconus is a progressive disease that thins and scars the corneal stroma. In keratoconus corneas, levels of degradative enzymes, including lysosomal acid phosphatase (LAP) and cathepsin B, are elevated, and those of the inhibitors alpha1-proteinase inhibitor (alpha 1-PI) and alpha 2-macroglobulin (alpha 2-M) are reduced, especially in the epithelial layer. An increased expression of the transcription factor Sp1 was also demonstrated. The role of Sp1 in regulation of the genes affected in keratoconus was examined in this study. DNA segments, containing 5'-flanking promoter sequences of the alpha 1-PI, LAP, cathepsin B, and alpha 2-M genes were ligated into the secreted alkaline phosphatase (SEAP) reporter gene vector. These constructs, along with the pSV beta-galactosidase control vector, were transfected into cultured human corneal epithelial and stromal cells and skin fibroblasts. Cotransfection with the Sp1 expression vector was performed in parallel. SEAP and beta-galactosidase enzyme activities were assayed. In corneal epithelial cells, as in stromal cells, alpha 1-PI promoter activity was suppressed by cotransfection of pPacSp1. The LAP, cathepsin B, and alpha 2-M promoters were functional in corneal cells, whereas activities of these promoters were much lower in skin fibroblasts. Cotransfection experiments indicated that the up- or downregulation of LAP, cathepsin B, and alpha 2-M observed in keratoconus-affected corneas was not mediated by Sp1. These results support the theory that the corneal epithelium, along with the stroma, is involved in keratoconus. An upstream role of Sp1 is indicated and the Sp1-mediated downregulation of the alpha 1-PI gene may be a key event in the disease development.

Activation of peroxisome proliferator-activated receptor-alpha protects the heart from ischemia/reperfusion injury.

PubMed

Yue, Tian-li; Bao, Weike; Jucker, Beat M; Gu, Juan-li; Romanic, Anne M; Brown, Peter J; Cui, Jianqi; Thudium, Douglas T; Boyce, Rogely; Burns-Kurtis, Cynthia L; Mirabile, Rosanna C; Aravindhan, Karpagam; Ohlstein, Eliot H

2003-11-11

Peroxisome proliferator-activated receptor-alpha (PPAR-alpha) is expressed in the heart and regulates genes involved in myocardial fatty acid oxidation (FAO). The role of PPAR-alpha in acute ischemia/reperfusion myocardial injury remains unclear. The coronary arteries of male mice were ligated for 30 minutes. After reperfusion for 24 hours, ischemic and infarct sizes were determined. A highly selective and potent PPAR-alpha agonist, GW7647, was administered by mouth for 2 days, and the third dose was given 1 hour before ischemia. GW7647 at 1 and 3 mg x kg(-1) x d(-1) reduced infarct size by 28% and 35%, respectively (P<0.01), and myocardial contractile dysfunction was also improved. Cardioprotection by GW7647 was completely abolished in PPAR-alpha-null mice. Ischemia/reperfusion downregulated mRNA expression of cardiac PPAR-alpha and FAO enzyme genes, decreased myocardial FAO enzyme activity and in vivo cardiac fat oxidation, and increased serum levels of free fatty acids. All of these changes were reversed by GW7647. Moreover, GW7647 attenuated ischemia/reperfusion-induced release of multiple proinflammatory cytokines and inhibited neutrophil accumulation and myocardial expression of matrix metalloproteinases-9 and -2. Furthermore, GW7647 inhibited nuclear factor-kappaB activation in the heart, accompanied by enhanced levels of inhibitor-kappaBalpha. Activation of PPAR-alpha protected the heart from reperfusion injury. This cardioprotection might be mediated through metabolic and antiinflammatory mechanisms. This novel effect of the PPAR-alpha agonist could provide an added benefit to patients treated with PPAR-alpha activators for dyslipidemia.

Acetyl-L-carnitine supplementation to old rats partially reverts the age-related mitochondrial decay of soleus muscle by activating peroxisome proliferator-activated receptor gamma coactivator-1alpha-dependent mitochondrial biogenesis.

PubMed

Pesce, Vito; Fracasso, Flavio; Cassano, Pierluigi; Lezza, Angela Maria Serena; Cantatore, Palmiro; Gadaleta, Maria Nicola

2010-01-01

The age-related decay of mitochondrial function is a major contributor to the aging process. We tested the effects of 2-month-daily acetyl-L-carnitine (ALCAR) supplementation on mitochondrial biogenesis in the soleus muscle of aged rats. This muscle is heavily dependent on oxidative metabolism. Mitochondrial (mt) DNA content, citrate synthase activity, transcript levels of some nuclear- and mitochondrial-coded genes (cytochrome c oxidase subunit IV [COX-IV], 16S rRNA, COX-I) and of some factors involved in the mitochondrial biogenesis signaling pathway (peroxisome proliferator-activated receptor gamma [PPARgamma] coactivator-1alpha [PGC-1alpha], mitochondrial transcription factor A mitochondrial [TFAM], mitochondrial transcription factor 2B [TFB2]), as well as the protein content of PGC-1alpha were determined. The results suggest that the ALCAR treatment in old rats activates PGC-1alpha-dependent mitochondrial biogenesis, thus partially reverting the age-related mitochondrial decay.

Phosphorylation of tyrosine 720 in the platelet-derived growth factor alpha receptor is required for binding of Grb2 and SHP-2 but not for activation of Ras or cell proliferation.

PubMed Central

Bazenet, C E; Gelderloos, J A; Kazlauskas, A

1996-01-01

Following binding of platelet-derived growth factor (PDGF), the PDGF alpha receptor (alphaPDGFR) becomes tyrosine phosphorylated and associates with a number of signal transduction molecules, including phospholipase Cgamma-1 (PLCgamma-1), phosphatidylinositol 3-kinase (PI3K), the phosphotyrosine phosphatase SHP-2, Grb2, and Src. Here, we present data identifying a novel phosphorylation site in the kinase insert domain of the alphaPDGFR at tyrosine (Y) 720. We replaced this residue with phenylalanine and expressed the mutated receptor (F720) in Patch fibroblasts that do not express the alphaPDGFR. Characterization of the F720 mutant indicated that binding of two proteins, SHP-2 and Grb2, was severely impaired, whereas PLCgamma-1 and PI3K associated to wild-type levels. In addition, mutating Y720 to phenylalanine dramatically reduced PDGF-dependent tyrosine phosphorylation of SHP-2. Since Y720 was required for recruitment of two proteins, we investigated the mechanism by which these two proteins associated with the alphaPDGFR. SHP-2 bound the alphaPDGFR directly, whereas Grb2 associated indirectly, most probably via SHP-2, as Grb2 and SHP-2 coimmunoprecipitated when SHP-2 was tyrosine phosphorylated. We also compared the ability of the wild-type and F720 alphaPDGFRs to mediate a number of downstream events. Preventing the alphaPDGFR from recruiting SHP-2 and Grb2 did not compromise PDGF-AA-induced activation of Ras, initiation of DNA synthesis, or growth of cells in soft agar. We conclude that phosphorylation of the alphaPDGFR at Y720 is required for association of SHP-2 and Grb2 and tyrosine phosphorylation of SHP-2; however, these events are not required for the alphaPDGFR to activate Ras or initiate a proliferative response. In addition, these findings reveal that while SHP-2 binds to both of the receptors, it binds in different locations: to the carboxy terminus of the betaPDGFR but to the kinase insert of the alphaPDGFR. PMID:8943348

Oxcarbazepine and its active metabolite, (S)-licarbazepine, exacerbate seizures in a mouse model of genetic generalized epilepsy.

PubMed

Kim, Tae Hwan; Reid, Christopher A; Petrou, Steven

2015-01-01

Oxcarbazepine (OXC), widely used to treat focal epilepsy, is reported to exacerbate seizures in patients with generalized epilepsy. OXC is metabolized to monohydroxy derivatives in two enantiomeric forms: (R)-licarbazepine and (S)-licarbazepine. Eslicarbazepine acetate is a recently approved antiepileptic drug that is rapidly metabolized to (S)-licarbazepine. It is not known whether (S)-licarbazepine exacerbates seizures. Here, we test whether OXC or either of its enantiomers exacerbates the number of spike-and-wave discharges (SWDs) in mice harboring the human γ-aminobutyric acid A receptor (GABAA)γ2(R43Q) mutation. OXC (20 mg/kg), (S)-licarbazepine (20 mg/kg), and (R)-licarbazepine (20 mg/kg) all significantly increased the number of SWDs, while their duration was unaffected. The potential for (S)-licarbazepine to exacerbate SWDs suggests that eslicarbazepine acetate should be used with caution in generalized epilepsy. Furthermore, generalized seizure exacerbation for first-, second-, and third-generation carbamazepine-based compounds is likely to occur through a common mechanism. Wiley Periodicals, Inc. © 2014 International League Against Epilepsy.

Glutathione regulation of redox-sensitive signals in tumor necrosis factor-{alpha}-induced vascular endothelial dysfunction

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

Tsou, T.-C.; Yeh, S.C.; Tsai, F.-Y.

2007-06-01

We investigated the regulatory role of glutathione in tumor necrosis factor-alpha (TNF-{alpha})-induced vascular endothelial dysfunction as evaluated by using vascular endothelial adhesion molecule expression and monocyte-endothelial monolayer binding. Since TNF-{alpha} induces various biological effects on vascular cells, TNF-{alpha} dosage could be a determinant factor directing vascular cells into different biological fates. Based on the adhesion molecule expression patterns responding to different TNF-{alpha} concentrations, we adopted the lower TNF-{alpha} (0.2 ng/ml) to rule out the possible involvement of other TNF-{alpha}-induced biological effects. Inhibition of glutathione synthesis by L-buthionine-(S,R)-sulfoximine (BSO) resulted in down-regulations of the TNF-{alpha}-induced adhesion molecule expression and monocyte-endothelial monolayermore » binding. BSO attenuated the TNF-{alpha}-induced nuclear factor-kappaB (NF-{kappa}B) activation, however, with no detectable effect on AP-1 and its related mitogen-activated protein kinases (MAPKs). Deletion of an AP-1 binding site in intercellular adhesion molecule-1 (ICAM-1) promoter totally abolished its constitutive promoter activity and its responsiveness to TNF-{alpha}. Inhibition of ERK, JNK, or NF-{kappa}B attenuates TNF-{alpha}-induced ICAM-1 promoter activation and monocyte-endothelial monolayer binding. Our study indicates that TNF-{alpha} induces adhesion molecule expression and monocyte-endothelial monolayer binding mainly via activation of NF-{kappa}B in a glutathione-sensitive manner. We also demonstrated that intracellular glutathione does not modulate the activation of MAPKs and/or their downstream AP-1 induced by lower TNF-{alpha}. Although AP-1 activation by the lower TNF-{alpha} was not detected in our systems, we could not rule out the possible involvement of transiently activated MAPKs/AP-1 in the regulation of TNF-{alpha}-induced adhesion molecule expression.« less

Comparison between testosterone enanthate-induced azoospermia and oligozoospermia in a male contraceptive study. V. Localization of higher 5 alpha-reductase activity to the reproductive tract in oligozoospermic men administered supraphysiological doses of testosterone.

PubMed

Anderson, R A; Kelly, R W; Wu, F C

1997-01-01

Sex steroid contraceptive regimes result in incomplete suppression of spermatogenesis in 30-45% of Caucasian men. The basis for this is unclear, but differences in the activity of 5 alpha-reductase (5 alpha R) have been demonstrated. Two isoforms of 5 alpha R have been described: 5 alpha R1 is found in skin, whereas the predominant from in reproductive tissues is 5 alpha R2. To investigate possible contributions of these isoenzymes, we have investigated androgen-dependent changes in seminal plasma androgens (5 alpha R2) and sebum production (5 alpha 1) during administration of a supraphysiological dose (200 mg IM weekly) of testosterone enanthate (TE) to 33 normal men. Eighteen men rapidly (< 20 weeks treatment) became azoospermic, the remainder having a mean sperm density of 2.0 +/- 0.6 x 10(6) at that time. The concentrations of testosterone and 3 alpha, 17 beta-androstanediol glucuronide (AdiolG) were lower in seminal plasma than in blood but rose by a similar degree (100%) after 16 weeks TE treatment in both groups. There were no differences in seminal-plasma concentration of testosterone or AdiolG between azoospermic and oligozoospermic responders, either pretreatment or after 16 weeks TE treatment. Although the concentrations of dihydrotestosterone (DHT) were similar in seminal plasma and blood pre- and posttreatment, there was a selective increase in seminal plasma DHT concentration in the oligozoospermic responders from 2.12 +/- 0.29 to 2.94 +/- 0.33 nmol/L (P < 0.05), while there was no significant change in the azoospermic responders (2.18 +/- 0.31-2.54 +/- 0.27 nmol/L) after 16 weeks of TE treatment. Dihydrotestosterone in seminal plasma is primarily derived from 5 alpha R activity in the epididymis. The concentration of prostaglandin E2 (PGE2) in seminal plasma was unchanged during TE treatment. Sebum excretion was increased during TE treatment, but there were no difference between azoospermic and oligozoospermic responders pretreatment or after 16 weeks TE treatment. These results are consistent with the hypothesis that incomplete suppression of spermatogenesis during TE treatment is associated with a relatively higher 5 alpha R activity in the reproductive tract (epididymis and/or testis) during TE treatment. As the predominant form of 5 alpha R in the reproductive tract is 5 alpha R2 (type 2), we conclude that the increase in activity derives from this form of the enzyme, rather than the type 1 form (5 alpha R1) predominantly found in nongenital skin.

Heterodimerization with beta2-adrenergic receptors promotes surface expression and functional activity of alpha1D-adrenergic receptors.

PubMed

Uberti, Michelle A; Hague, Chris; Oller, Heide; Minneman, Kenneth P; Hall, Randy A

2005-04-01

The alpha1D-adrenergic receptor (alpha1D-AR) is a G protein-coupled receptor (GPCR) that is poorly trafficked to the cell surface and largely nonfunctional when heterologously expressed by itself in a variety of cell types. We screened a library of approximately 30 other group I GPCRs in a quantitative luminometer assay for the ability to promote alpha1D-AR cell surface expression. Strikingly, these screens revealed only two receptors capable of inducing robust increases in the amount of alpha1D-AR at the cell surface: alpha1B-AR and beta2-AR. Confocal imaging confirmed that coexpression with beta2-AR resulted in translocation of alpha1D-AR from intracellular sites to the plasma membrane. Additionally, coimmunoprecipitation studies demonstrated that alpha1D-AR and beta2-AR specifically interact to form heterodimers when coexpressed in HEK-293 cells. Ligand binding studies revealed an increase in total alpha1D-AR binding sites upon coexpression with beta2-AR, but no apparent effect on the pharmacological properties of the receptors. In functional studies, coexpression with beta2-AR significantly enhanced the coupling of alpha1D-AR to norepinephrine-stimulated Ca2+ mobilization. Heterodimerization of beta2-AR with alpha1D-AR also conferred the ability of alpha1D-AR to cointernalize upon beta2-AR agonist stimulation, revealing a novel mechanism by which these different adrenergic receptor subtypes may regulate each other's activity. These findings demonstrate that the selective association of alpha1D-AR with other receptors is crucial for receptor surface expression and function and also shed light on a novel mechanism of cross talk between alpha1- and beta2-ARs that is mediated through heterodimerization and cross-internalization.

The Effect of Fucoidan from the Brown Alga Fucus evanescence on the Activity of α-N-Acetylgalactosaminidase of Human Colon Carcinoma Cells.

PubMed

Bakunina, Irina; Chadova, Oksana; Malyarenko, Olesya; Ermakova, Svetlana

2018-05-10

α- N -acetylgalactosaminidase (EC 3.2.1.49) (alpha-NaGalase) catalyzes the hydrolysis of N -acetamido-2-deoxy-α-d-galactoside residues from non-reducing ends of various complex carbohydrates and glycoconjugates. It is known that human cancer cells express an alpha-NaGalase, which accumulates in the blood plasma of patients. The enzyme deglycosylates the Gc protein-derived macrophage activating factor (GcMAF) and inhibits macrophage activity acting as an immunosuppressor. The high specific activity 0.033 ± 0.002 μmol mg −1 min −1 of the enzyme was found in human colon carcinoma cells DLD-1. The alpha-NaGalase of DLD-1 cells was isolated and biochemical characterized. The enzyme exhibits maximum activity at pH 5.2 and temperature 55 °C. The K m is 2.15 mM, V max ⁻0.021 μmol min −1 mL −1 , k cat ⁻1.55 min −1 and k cat / K m ⁻0.72 min −1 mM −1 at 37 °C, pH 5.2. The effects of fucoidan from the brown alga Fucus evanescence on the activity of alpha-NaGalase in human colon carcinoma DLD-1 cells and on the biosynthesis of this enzyme were investigated. It was shown that fucoidan did not inhibit free alpha-NaGalase, however, it reduced the expression of the enzyme in the DLD-1 cells at IC 50 73 ± 4 μg mL −1 .

Chondrogenic differentiation of growth factor-stimulated precursor cells in cartilage repair tissue is associated with increased HIF-1alpha activity.

PubMed

Gelse, K; Mühle, C; Knaup, K; Swoboda, B; Wiesener, M; Hennig, F; Olk, A; Schneider, H

2008-12-01

To investigate the chondrogenic potential of growth factor-stimulated periosteal cells with respect to the activity of Hypoxia-inducible Factor 1alpha (HIF-1alpha). Scaffold-bound autologous periosteal cells, which had been activated by Insulin-like Growth Factor 1 (IGF-1) or Bone Morphogenetic Protein 2 (BMP-2) gene transfer using both adeno-associated virus (AAV) and adenoviral (Ad) vectors, were applied to chondral lesions in the knee joints of miniature pigs. Six weeks after transplantation, the repair tissues were investigated for collagen type I and type II content as well as for HIF-1alpha expression. The functional role of phosphatidylinositol 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) and mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK) signaling on BMP-2/IGF-1-induced HIF-1alpha expression was assessed in vitro by employing specific inhibitors. Unstimulated periosteal cells formed a fibrous extracellular matrix in the superficial zone and a fibrocartilaginous matrix in deep zones of the repair tissue. This zonal difference was reflected by the absence of HIF-1alpha staining in superficial areas, but moderate HIF-1alpha expression in deep zones. In contrast, Ad/AAVBMP-2-stimulated periosteal cells, and to a lesser degree Ad/AAVIGF-1-infected cells, adopted a chondrocyte-like phenotype with strong intracellular HIF-1alpha staining throughout all zones of the repair tissue and formed a hyaline-like matrix. In vitro, BMP-2 and IGF-1 supplementation increased HIF-1alpha protein levels in periosteal cells, which was based on posttranscriptional mechanisms rather than de novo mRNA synthesis, involving predominantly the MEK/ERK pathway. This pilot experimental study on a relatively small number of animals indicated that chondrogenesis by precursor cells is facilitated in deeper hypoxic zones of cartilage repair tissue and is stimulated by growth factors which enhance HIF-1alpha activity.

Dynamic properties of biologically active synthetic heparin-like hexasaccharides.

PubMed

Angulo, Jesús; Hricovíni, Milos; Gairi, Margarida; Guerrini, Marco; de Paz, José Luis; Ojeda, Rafael; Martín-Lomas, Manuel; Nieto, Pedro M

2005-10-01

A complete study of the dynamics of two synthetic heparin-like hexasaccharides, D-GlcNHSO3-6-SO4-alpha-(1-->4)-L-IdoA-2-SO4-alpha-(1-->4)-D-GlcNHSO3-6-SO4-alpha-(1-->4)-L-IdoA-2-SO4-alpha-(1-->4)-D-GlcNHSO3-6-SO4-alpha-(1-->4)-L-IdoA-2-SO4-alpha-1-->iPr (1) and -->4)-L-IdoA-2-SO4-alpha-(1-->4)-D-GlcNHAc-6-SO4-alpha-(1-->4)-L-IdoA-alpha-(1-->4)-D-GlcNHSO3-alpha-(1-->4)-L-IdoA-2-SO4-alpha-1-->iPr (2), has been performed using 13C-nuclear magnetic resonance (NMR) relaxation parameters, T1, T2, and heteronuclear nuclear Overhauser effect (NOEs). Compound 1 is constituted from sequences corresponding to the major polysaccharide heparin region, while compound 2 contains a sequence never found in natural heparin. They differ from each other only in sulphation patterns, and are capable of stimulating fibroblast growth factors (FGFs)-1 induced mitogenesis. Both oligosaccharides exhibit a remarkable anisotropic overall motion in solution as revealed by their anisotropic ratios (tau /tau||), 4.0 and 3.0 respectively. This is a characteristic behaviour of natural glycosaminoglycans (GAG) which has also been observed for the antithrombin (AT) binding pentasaccharide D-GlcNHSO3-6-SO4-alpha-(1-->4)-D-GlcA-beta-(1-->4)-D-GlcNHSO3-(3,6-SO4)-alpha-(1-->4)-L-IdoA-2-SO4-alpha-(1-->4)-D-GlcNHSO3-6-SO4-alpha-1-->Me (3) (Hricovíni, M., Guerrini, M., Torri, G., Piani, S., and Ungarelli, F. (1995) Conformational analysis of heparin epoxide in aqueous solution. An NMR relaxation study. Carbohydr. Res., 277, 11-23). The motional properties observed for 1 and 2 provide additional support to the suitability of these compounds as heparin models in agreement with previous structural (de Paz, J.L., Angulo, J., Lassaletta, J.M., Nieto, P.M., Redondo-Horcajo, M., Lozano, R.M., Jiménez-Gallego, G., and Martín-Lomas, M. (2001) The activation of fibroblast growth factors by heparin: synthesis, structure and biological activity of heparin-like oligosaccharides. Chembiochem, 2, 673-685; Ojeda, R., Angulo, J., Nieto, P.M., and Martin-Lomas. M. (2002) The activation of fibroblast growth factors by heparin: synthesis and structural study of rationally modified heparin-like oligosaccharides. Can. J. Chem,. 80, 917-936; Lucas, R., Angulo, J., Nieto, P.M., and Martin-Lomas, M. (2003) Synthesis and structural studies of two new heparin-like hexasaccharides. Org. Biomol. Chem., 1, 2253-2266) and biological data (Angulo, J., Ojeda, R., de Paz, J.L., Lucas, R., Nieto, P.M., Lozano, R.M., Redondo-Horcajo, M., Giménez-Gallego, G., and Martín-Lomas, M. (2004) The activation of fibroblast growth factors (FGFs) by glycosaminoglycans: influence of the sulphation pattern on the biological activity of FGF-1. Chembiochem, 5, 55-61). Fast internal motions observed for the less sulphated compound 2, as compared with 1, may be related to their different behavior in stimulating FGF1-induced mitogenic activity.

Alpha-lipoic acid improves high-fat diet-induced hepatic steatosis by modulating the transcription factors SREBP-1, FoxO1 and Nrf2 via the SIRT1/LKB1/AMPK pathway.

PubMed

Yang, Yi; Li, Wang; Liu, Yang; Sun, Yuning; Li, Yan; Yao, Qing; Li, Jianning; Zhang, Qian; Gao, Yujing; Gao, Ling; Zhao, Jiajun

2014-11-01

Understanding the mechanism by which alpha-lipoic acid supplementation has a protective effect upon nonalcoholic fatty liver disease in vivo and in vitro may lead to targets for preventing hepatic steatosis. Male C57BL/6J mice were fed a normal diet, high-fat diet or high-fat diet supplemented with alpha-lipoic acid for 24 weeks. HepG2 cells were incubated with normal medium, palmitate or alpha-lipoic acid. The lipid-lowering effects were measured. The protein expression and distribution were analyzed by Western blot, immunoprecipitation and immunofluorescence, respectively. We found that alpha-lipoic acid enhanced sirtuin 1 deacetylase activity through liver kinase B1 and stimulated AMP-activated protein kinase. By activating the sirtuin 1/liver kinase B1/AMP-activated protein kinase pathway, the translocation of sterol regulatory element-binding protein-1 into the nucleus and forkhead box O1 into the cytoplasm was prevented. Alpha-lipoic acid increased adipose triacylglycerol lipase expression and decreased fatty acid synthase abundance. In in vivo and in vitro studies, alpha-lipoic acid also increased nuclear NF-E2-related factor 2 levels and downstream target amounts via the sirtuin 1 pathway. Alpha-lipoic acid eventually reduced intrahepatic and serum triglyceride content. The protective effects of alpha-lipoic acid on hepatic steatosis appear to be associated with the transcription factors sterol regulatory element-binding protein-1, forkhead box O1 and NF-E2-related factor 2. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Olfactory Bulb [alpha][subscript 2]-Adrenoceptor Activation Promotes Rat Pup Odor-Preference Learning via a cAMP-Independent Mechanism

ERIC Educational Resources Information Center

Shakhawat, Amin MD.; Harley, Carolyn W.; Yuan, Qi

2012-01-01

In this study, three lines of evidence suggest a role for [alpha][subscript 2]-adrenoreceptors in rat pup odor-preference learning: olfactory bulb infusions of the [alpha][subscript 2]-antagonist, yohimbine, prevents learning; the [alpha][subscript 2]-agonist, clonidine, paired with odor, induces learning; and subthreshold clonidine paired with…

JPRS Report, Science & Technology, USSR: Life Sciences.

DTIC Science & Technology

1987-08-04

alpha 2 preparation, produced by E. coli cells, is described and discussed. Cytokinin activity was determined by inducement of betacyanin synthesis in...the dark by cytokinin in the presence of thyrosine, used as a substrate. Experiments with A. caudatus sprouts showed that IFN alpha 2 produced...of IFN- alpha 2 appeared at concentration of 0.1 unit/ml but increase of concentration reduced cytokinin activity. In control experiments, induction

Naturally occurring disulfide-bound dimers of three-fingered toxins: a paradigm for biological activity diversification.

PubMed

Osipov, Alexey V; Kasheverov, Igor E; Makarova, Yana V; Starkov, Vladislav G; Vorontsova, Olga V; Ziganshin, Rustam Kh; Andreeva, Tatyana V; Serebryakova, Marina V; Benoit, Audrey; Hogg, Ronald C; Bertrand, Daniel; Tsetlin, Victor I; Utkin, Yuri N

2008-05-23

Disulfide-bound dimers of three-fingered toxins have been discovered in the Naja kaouthia cobra venom; that is, the homodimer of alpha-cobratoxin (a long-chain alpha-neurotoxin) and heterodimers formed by alpha-cobratoxin with different cytotoxins. According to circular dichroism measurements, toxins in dimers retain in general their three-fingered folding. The functionally important disulfide 26-30 in polypeptide loop II of alpha-cobratoxin moiety remains intact in both types of dimers. Biological activity studies showed that cytotoxins within dimers completely lose their cytotoxicity. However, the dimers retain most of the alpha-cobratoxin capacity to compete with alpha-bungarotoxin for binding to Torpedo and alpha7 nicotinic acetylcholine receptors (nAChRs) as well as to Lymnea stagnalis acetylcholine-binding protein. Electrophysiological experiments on neuronal nAChRs expressed in Xenopus oocytes have shown that alpha-cobratoxin dimer not only interacts with alpha7 nAChR but, in contrast to alpha-cobratoxin monomer, also blocks alpha3beta2 nAChR. In the latter activity it resembles kappa-bungarotoxin, a dimer with no disulfides between monomers. These results demonstrate that dimerization is essential for the interaction of three-fingered neurotoxins with heteromeric alpha3beta2 nAChRs.

Molecular analysis and functional expression of the human type E neuronal Ca2+ channel alpha 1 subunit.

PubMed

Schneider, T; Wei, X; Olcese, R; Costantin, J L; Neely, A; Palade, P; Perez-Reyes, E; Qin, N; Zhou, J; Crawford, G D

1994-01-01

A human brain alpha 1 Ca2+ channel subunit was cloned and expressed in Xenopus laevis oocytes. The open reading frame, encoding 2,312 amino acids, has high homology to the marine ray doe-1, the rat E-type, and the rabbit brain BII alpha 1 subunits. The amino and carboxy termini of this human.E-type alpha 1 subunit (alpha 1E) are most similar to the rabbit BII-1 splice variant, the remainder being colinear with the BII alpha 1 with the exception of two insertions, one of 43 amino acids in the C-terminus and another of 7 amino acids, found also in the rat alpha 1E, between domains II and III. Two potential Ca2+ binding sites are predicted from its primary structure. The expression of inward Ba2+ currents reveals voltage-dependent activation and inactivation measured by the cut-open oocyte vaseline-gap technique, with kinetics that correspond to that of a high-voltage-activated neuronal Ca2+ channel, and pharmacologic properties that resemble those of some low-voltage-activated neuronal Ca2+ currents. The human alpha 1E currents are insensitive to omega-conotoxin-GVIA (1 microM), omega-agatoxin-IVA (200 nM), a synthetic funnel web spider toxin (FTX, 20 microM), and Bay-K8644 (0.5 microM); they are inhibited 20% by high concentrations of methoxyverapamil and diltiazem, 65% by 0.1% crude funnel web spider venom and 100% by Ni2+ (IC50 = 30 nM). Single-channel records show a complex activity pattern with several apparent conductance states, the largest having a conductance of 14 pS.

Generation of reactive oxygen species in the reaction catalyzed by alpha-ketoglutarate dehydrogenase.

PubMed

Tretter, Laszlo; Adam-Vizi, Vera

2004-09-08

Alpha-ketoglutarate dehydrogenase (alpha-KGDH), a key enzyme in the Krebs' cycle, is a crucial early target of oxidative stress (Tretter and Adam-Vizi, 2000). The present study demonstrates that alpha-KGDH is able to generate H(2)O(2) and, thus, could also be a source of reactive oxygen species (ROS) in mitochondria. Isolated alpha-KGDH with coenzyme A (HS-CoA) and thiamine pyrophosphate started to produce H(2)O(2) after addition of alpha-ketoglutarate in the absence of nicotinamide adenine dinucleotide-oxidized (NAD(+)). NAD(+), which proved to be a powerful inhibitor of alpha-KGDH-mediated H(2)O(2) formation, switched the H(2)O(2) forming mode of the enzyme to the catalytic [nicotinamide adenine dinucleotide-reduced (NADH) forming] mode. In contrast, NADH stimulated H(2)O(2) formation by alpha-KGDH, and for this, neither alpha-ketoglutarate nor HS-CoA were required. When all of the substrates and cofactors of the enzyme were present, the NADH/NAD(+) ratio determined the rate of H(2)O(2) production. The higher the NADH/NAD(+) ratio the higher the rate of H(2)O(2) production. H(2)O(2) production as well as the catalytic function of the enzyme was activated by Ca(2+). In synaptosomes, using alpha-ketoglutarate as respiratory substrate, the rate of H(2)O(2) production increased by 2.5-fold, and aconitase activity decreased, indicating that alpha-KGDH can generate H(2)O(2) in in situ mitochondria. Given the NADH/NAD(+) ratio as a key regulator of H(2)O(2) production by alpha-KGDH, it is suggested that production of ROS could be significant not only in the respiratory chain but also in the Krebs' cycle when oxidation of NADH is impaired. Thus alpha-KGDH is not only a target of ROS but could significantly contribute to generation of oxidative stress in the mitochondria.

HNF4alpha dysfunction as a molecular rational for cyclosporine induced hypertension.

PubMed

Niehof, Monika; Borlak, Jürgen

2011-01-27

Induction of tolerance against grafted organs is achieved by the immunosuppressive agent cyclosporine, a prominent member of the calcineurin inhibitors. Unfortunately, its lifetime use is associated with hypertension and nephrotoxicity. Several mechanism for cyclosporine induced hypertension have been proposed, i.e. activation of the sympathetic nervous system, endothelin-mediated systemic vasoconstriction, impaired vasodilatation secondary to reduction in prostaglandin and nitric oxide, altered cytosolic calcium translocation, and activation of the renin-angiotensin system (RAS). In this regard the molecular basis for undue RAS activation and an increased signaling of the vasoactive oligopeptide angiotensin II (AngII) remain elusive. Notably, angiotensinogen (AGT) is the precursor of AngII and transcriptional regulation of AGT is controlled by the hepatic nuclear factor HNF4alpha. To better understand the molecular events associated with cyclosporine induced hypertension, we investigated the effect of cyclosporine on HNF4alpha expression and activity and searched for novel HNF4alpha target genes among members of the RAS cascade. Using bioinformatic algorithm and EMSA bandshift assays we identified angiotensin II receptor type 1 (AGTR1), angiotensin I converting enzyme (ACE), and angiotensin I converting enzyme 2 (ACE2) as genes targeted by HNF4alpha. Notably, cyclosporine represses HNF4alpha gene and protein expression and its DNA-binding activity at consensus sequences to AGT, AGTR1, ACE, and ACE2. Consequently, the gene expression of AGT, AGTR1, and ACE2 was significantly reduced as evidenced by quantitative real-time RT-PCR. While RAS is composed of a sophisticated interplay between multiple factors we propose a decrease of ACE2 to enforce AngII signaling via AGTR1 to ultimately result in vasoconstriction and hypertension. Taken collectively we demonstrate cyclosporine to repress HNF4alpha activity through calcineurin inhibitor mediated inhibition of nuclear factor of activation of T-cells (NFAT) which in turn represses HNF4alpha that leads to a disturbed balance of RAS.

Low concentration of arsenite exacerbates UVR-induced DNA strand breaks by inhibiting PARP-1 activity

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

Qin Xujun; Department of Toxicology, Fourth Military Medical University, Xi'an, Shaanxi, 710032; Hudson, Laurie G.

2008-10-01

Epidemiological studies have associated arsenic exposure with many types of human cancers. Arsenic has also been shown to act as a co-carcinogen even at low concentrations. However, the precise mechanism of its co-carcinogenic action is unknown. Recent studies indicate that arsenic can interfere with DNA-repair processes. Poly(ADP-ribose) polymerase (PARP)-1 is a zinc-finger DNA-repair protein, which can promptly sense DNA strand breaks and initiate DNA-repair pathways. In the present study, we tested the hypothesis that low concentrations of arsenic could inhibit PAPR-1 activity and so exacerbate levels of ultraviolet radiation (UVR)-induced DNA strand breaks. HaCat cells were treated with arsenite and/ormore » UVR, and then DNA strand breaks were assessed by comet assay. Low concentrations of arsenite ({<=} 2 {mu}M) alone did not induce significant DNA strand breaks, but greatly enhanced the DNA strand breaks induced by UVR. Further studies showed that 2 {mu}M arsenite effectively inhibited PARP-1 activity. Zinc supplementation of arsenite-treated cells restored PARP-1 activity and significantly diminished the exacerbating effect of arsenite on UVR-induced DNA strand breaks. Importantly, neither arsenite treatment, nor zinc supplementation changed UVR-triggered reactive oxygen species (ROS) formation, suggesting that their effects upon UVR-induced DNA strand breaks are not through a direct free radical mechanism. Combination treatments of arsenite with PARP-1 inhibitor 3-aminobenzamide or PARP-1 siRNA demonstrate that PARP-1 is the target of arsenite. Together, these findings show that arsenite at low concentration exacerbates UVR-induced DNA strand breaks by inhibiting PARP-1 activity, which may represent an important mechanism underlying the co-carcinogenicity of arsenic.« less

[CaCO3 stimulates alpha-ketoglutarate accumulation during pyruvate fermentation by Torulopsis glabrata].

PubMed

Liu, Li-Ming; Li, Yin; Du, Guo-Cheng; Chen, Jian

2003-11-01

A large amount of alpha-ketoglutarate (alpha-KG) (6.8 g/L) was accumulated in flask culture when CaCO3 was used as a buffering agent in the production of pyruvate by multi-vitamin auxotrophic yeast Torulopsis glabrata CCTCC M202019. In a 5 L jar-fermentor, less alpha-KG (1.3 g/L) was produced when NaOH was used to adjust the pH, while more alpha-KG (11.5 g/L) detected when CaCO3 was used as the buffer. In the latter case, the molar carbon ratio of pyruvate to alpha-KG (C(PYR)/ CalphaKG) was similar to that obtained in flask culture, suggesting the accumulation of alpha-ketoglutarate was related to the addition of CaCO3. Furthermore, it was found that: (1) delaying the addition time of CaCO3 decreased the a-ketoglutarate formation but increased C(PYR)/ C(alphaKG); and (2) under vitamin limitation conditions increasing the concentration of CaCO3 led to an increased a-KG accumulation at the expenses of pyruvate. To study which ions in CaCO3 was responsible for the accumulation of alpha-KG, the effects of different pH buffers on the a-KG accumulation were studied. The level of alpha-KG was found to correlate with the levels of both Ca2+ and CO3(2-), with Ca2+ played a dominant role and CO3(2-) played a minor role. To find out which pathway was responsible for the accumulation of alpha-KG, the effects of biotin and thiamine on alpha-KG accumulation was investigated. The increase in biotin concentration led to an increase in alpha-KG accumulation and a decrease in C(PYR)/ C(alpha-KG), while the levels of alpha-KG and C(PYR)/C(alphaKG) were not affected by thiamine concentration. The activity of pyruvate carboxylase was increased as much as 40% when the medium was supplemented with Ca2+ . On the other hand, the activity of the pyruvate dehydrogenase complex was unaffected by the presence of Ca2+. To conclude, the higher level of a-KG was caused by higher activity of pyruvate carboxylase stimulated by Ca2+, with CO3(2-) served as the substrate of the reaction.

Nitric oxide production and monoamine oxidase activity in cancer patients during interferon-alpha therapy.

PubMed

Fekkes, Durk; Van Gool, Arthur R; Bannink, Marjolein; Sleijfer, Stefan; Kruit, Wim H J; van der Holt, Bronno; Eggermont, Alexander M M; Hengeveld, Michiel W; Stoter, Gerrit

2009-10-01

Both increased and decreased nitric oxide (NO) synthesis have been reported in patients treated with interferon-alpha (IFN-alpha). Animal studies showed that IFN-alpha administration results in increased levels of biogenic amines, subsequent activation of monoamine oxidases (MAOs), and finally in a change in NO production due to the H(2)O(2) generated by MAOs. We examined the potential relationship between NO production in plasma and MAO-B activity in platelets of 43 cancer patients during 8 weeks of treatment with IFN-alpha. NO synthesis was quantitated by measuring both the ratio of citrulline and arginine (CIT/ARG-ratio) and total nitrite/nitrate (NOx) levels. Compared to baseline, MAO activity and NOx increased, while the CIT/ARG-ratio decreased. No associations were found between NOx, MAO and CIT/ARG-ratio. Only few associations were observed between changes in the biochemical parameters and changes in psychopathology induced by IFN-alpha, of which the association between changes in CIT and lassitude was the most consistent. The results suggest that peripheral NO production and MAO activity are unrelated to each other, and that peripheral changes in these biochemical parameters induced by IFN-alpha are unlikely to contribute to definite psychiatric disturbance.

Construction of promoter-probe shuttle vectors for Escherichia coli and corynebacteria on the basis of promoterless alpha-amylase gene.

PubMed

Ugorcáková, J; Bukovská, G; Timko, J

2000-01-01

We constructed new promoter-probe vectors for E. coli and corynebacteria based on the promoterless alpha-amylase gene originating from Bacillus subtilis. Vectors pJUPAE1 and pJUPAE2 are suitable for isolation of transcriptionally active fragments from plasmids, phages or genomic DNA. alpha-Amylase activity can be easily visually detected on agar plates containing a chromogenic substrate, or by direct measurement of alpha-amylase activity.

Inactivation of chloroplast H(+)-ATPase by modification of Lys beta 359, Lys alpha 176 and Lys alpha 266.

PubMed

Horbach, M; Meyer, H E; Bickel-Sandkötter, S

1991-09-01

Treatment of isolated, latent chloroplast ATPase with pyridoxal-5-phosphate (pyridoxal-P) in presence of Mg2+ causes inhibition of dithiothreitol-activated plus heat-activated ATP hydrolysis. The amount of [3H]pyridoxal-P bound to chloroplast coupling factor 1 (CF1) was estimated to run up to 6 +/- 1 pyridoxal-P/enzyme, almost equally distributed between the alpha- and beta-subunits. Inactivation, however, is complete after binding of 1.5-2 pyridoxal-P/CF1, suggesting that two covalently modified lysines prevent the activation of the enzyme. ADP as well as ATP in presence of Mg2+ protects the enzyme against inactivation and concomittantly prevents incorporation of a part of the 3H-labeled pyridoxal-P into beta- and alpha-subunits. Phosphate prevents labeling of the alpha-subunit, but has only a minor effect on protection against inactivation. The data indicate a binding site at the interface between the alpha- and beta-subunits. Cleavage of the pyridoxal-P-labeled subunits with cyanogen bromide followed by sequence analysis of the labeled peptides led to the detection of Lys beta 359, Lys alpha 176 and Lys alpha 266, which are closely related to proposed nucleotide-binding regions of the alpha- and beta-subunits.

Modulation of the immunogenicity of the Trypanosoma congolense cysteine protease, congopain, through complexation with alpha(2)-macroglobulin.

PubMed

Huson, Laura Elizabeth Joan; Authié, Edith; Boulangé, Alain Francçois; Goldring, James Phillip Dean; Coetzer, Theresa Helen Taillefer

2009-01-01

The protozoan parasite Trypanosoma congolense is the main causative agent of livestock trypanosomosis. Congopain, the major lysosomal cysteine proteinase of T. congolense, contributes to disease pathogenesis, and antibody-mediated inhibition of this enzyme may contribute to mechanisms of trypanotolerance. The potential of different adjuvants to facilitate the production of antibodies that would inhibit congopain activity was evaluated in the present study. Rabbits were immunised with the recombinant catalytic domain of congopain (C2), either without adjuvant, with Freund's adjuvant or complexed with bovine or rabbit alpha(2)-macroglobulin (alpha(2)M). The antibodies were assessed for inhibition of congopain activity. Rabbits immunised with C2 alone produced barely detectable anti-C2 antibody levels and these antibodies had no effect on recombinant C2 or native congopain activity. Rabbits immunised with C2 and Freund's adjuvant produced the highest levels of anti-C2 antibodies. These antibodies either inhibited C2 and native congopain activity to a small degree, or enhanced their activity, depending on time of production after initial immunisation. Rabbits receiving C2-alpha(2)M complexes produced moderate levels of anti-C2 antibodies and these antibodies consistently showed the best inhibition of C2 and native congopain activity of all the antibodies, with maximum inhibition of 65%. Results of this study suggest that antibodies inhibiting congopain activity could be raised in livestock with a congopain catalytic domain-alpha(2)M complex. This approach improves the effectiveness of the antigen as an anti-disease vaccine candidate for African trypanosomosis.

Different patterns of 5{alpha}-reductase expression, cellular distribution, and testosterone metabolism in human follicular dermal papilla cells

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

Liu, Shicheng; Yamauchi, Hitoshi

Androgens regulate hair growth, and 5{alpha}-reductase (5{alpha}R) plays a pivotal role in the action of androgens on target organs. To clarify the molecular mechanisms responsible for controlling hair growth, the present study presents evidence that the human follicular dermal papilla cells (DPCs) from either beard (bDPCs) or scalp hair (sDPCs) possess endogenous 5{alpha}R activity. Real-time RT-PCR revealed that the highest level of 5{alpha}R1 mRNA was found in bDPCs, followed by sDPCs, and a low but detectable level of 5{alpha}R1 mRNA was observed in fibroblasts. Minimally detectable levels of 5{alpha}R2 mRNA were found in all three cell types. A weak bandmore » at 26 kDa corresponding to the human 5{alpha}R1 protein was detected by Western blot in both DPCs, but not in fibroblasts. Immuonofluorescence analysis confirmed that 5{alpha}R1 was localized to the cytoplasm rather than in the nuclei in both DPCs Furthermore, a 5{alpha}R assay using [{sup 14}C]testosterone labeling in intact cells revealed that testosterone was transformed primarily into androstenedione, and in small amounts, into DHT. Our results demonstrate that the 5{alpha}R activities of either bDPCs or sDPCs are stronger than that of dermal fibroblasts, despite the fact that the major steroidogenic activity is attributed to 17{beta}-HSD rather than 5{alpha}R among the three cell types. The 5{alpha}R1 inhibitor MK386 exhibited a more potent inhibitory effect on 5{alpha}R activity than finasteride (5{alpha}R2 inhibitor) in bDPCs.« less

Therapeutic activities of intravenous immunoglobulins in multiple sclerosis involve modulation of chemokine expression.

PubMed

Pigard, Nadine; Elovaara, Irina; Kuusisto, Hanna; Paalavuo, Raija; Dastidar, Prasun; Zimmermann, Klaus; Schwarz, Hans-Peter; Reipert, Birgit

2009-04-30

The objective of this study was to identify genes that are differentially expressed in peripheral T cells of patients with MS exacerbation receiving treatment with IVIG. Using microarray analysis, we identified 360 genes that were at least two-fold up- or down-regulated. The expression of four representative genes (PTGER4, CXCL5, IL11 and CASP2) was confirmed by quantitative PCR. Four of the differentially expressed genes encode chemokines (CXCL3, CXCL5, CCL13 and XCL2) that are involved in directing leukocyte migration. We suggest that the modulation of chemokine expression in peripheral T cells contributes to the beneficial activity of IVIG in patients with MS exacerbation.

Supplementation with mixed tocopherols increases serum and blood cell gamma-tocopherol but does not alter biomarkers of platelet activation in subjects with type 2 diabetes.

PubMed

Clarke, Michael W; Ward, Natalie C; Wu, Jason H Y; Hodgson, Jonathan M; Puddey, Ian B; Croft, Kevin D

2006-01-01

Some studies have shown potential benefit of vitamin E on platelet function, but several clinical trials failed to show improved cardiovascular outcome with alpha-tocopherol supplementation. Gamma-tocopherol, a major dietary form of vitamin E, may have protective properties different from those of alpha-tocopherol. We compared the effects of supplementation with alpha-tocopherol (500 mg) and a gamma-tocopherol-rich compound (500 mg, containing 60% gamma-tocopherol) on serum and cellular tocopherol concentrations, urinary tocopherol metabolite excretion, and in vivo platelet activation in subjects with type 2 diabetes. Fifty-eight subjects were randomly assigned to receive either 500 mg alpha-tocopherol/d, 500 mg mixed tocopherols/d, or matching placebo. Serum, erythrocyte, and platelet tocopherol and urinary metabolite concentrations were measured at baseline and after the 6-wk intervention. Soluble CD40 ligand, urinary 11-dehydro-thromboxane B2, serum thromboxane B2, soluble P-selectin, and von Willebrand factor were measured as biomarkers of in vivo platelet activation. Serum alpha-tocopherol increased with both tocopherol treatments. Serum and cellular gamma-tocopherol increased 4-fold (P < 0.001) in the mixed tocopherol group, whereas red blood cell gamma-tocopherol decreased significantly after alpha-tocopherol supplementation. Excretion of alpha-carboxyethyl-hydroxychroman increased significantly after supplementation with alpha-tocopherol and mixed tocopherols. Excretion of gamma-carboxyethyl-hydroxychroman increased significantly after supplementation with mixed tocopherols and after that with alpha-tocopherol, which may reflect the displacement of gamma-tocopherol by alpha-tocopherol due to incorporation of the latter into lipoproteins in the liver. Neither treatment had any significant effect on markers of platelet activation. Supplementation with alpha-tocopherol decreased red blood cell gamma-tocopherol, whereas mixed tocopherols increased both serum alpha-tocopherol and serum and cellular gamma-tocopherol. Changes in serum tocopherol closely reflect changes in cellular concentrations of tocopherols after supplementation.

Functional properties of an isolated. cap alpha beta. heterodimeric human placenta insulin-like growth factor 1 receptor complex

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

Feltz, S.M.; Swanson, M.L.; Wemmie, J.A.

1988-05-03

Treatment of human placenta membranes at pH 8.5 in the presence of 2.0 mM dithiothreitol (DTT) for 5 min, followed by the simultaneous removal of the DTT and pH adjustment of pH 7.6, resulted in the formation of a functional ..cap alpha beta.. heterodimeric insulin-like growth factor 1 (IGF-1) receptor complex from the native ..cap alpha../sub 2/..beta../sub 2/ heterotetrameric disulfide-linked state. The membrane-bound ..cap alpha beta.. heterodimeric complex displayed similar curvilinear /sup 125/I-IGF-1 equilibrium binding compared to the ..cap alpha../sub 2/..beta../sub 2/ heterotetrameric complex. /sup 125/I-IGF-1 binding to both the isolated ..cap alpha../sub 2/..beta../sub 2/ heterotetrameric and ..cap alpha beta..more » heterodimeric complexes demonstrated a marked straightening of the Scatchard plots, compared to the placenta membrane-bound IGF-1 receptors, with a 2-fold increase in the high-affinity binding component. IGF-1 stimulation of IGF-1 receptor autophosphorylation indicated that the ligand-dependent activation of ..cap alpha beta.. heterodimeric protein kinase activity occurred concomitant with the reassociation into a covalent ..cap alpha../sub 2/..beta../sub 2/ heterotetrameric state. These data demonstrate that (i) a combination of alkaline pH and DTT treatment of human placenta membranes results in the formation of an ..cap alpha beta.. heterodimeric IGF-1 receptor complex, (ii) unlike the insulin receptor, high-affinity homogeneous IGF-1 binding occurs in both the ..cap alpha../sub 2/..beta../sub 2/ heterotetrameric and ..cap alpha beta.. heterodimeric complexes, and (iii) IGF-1-dependent autophosphorylation of the ..cap alpha beta.. heterodimeric IGF-1 receptor complex correlates wit an IGF-1 dependent covalent reassociation into an ..cap alpha../sub 2/..beta../sub 2/ heterotetrameric disulfide-linked state.« less

Ca2+ permeability through rat cloned alpha9-containing nicotinic acetylcholine receptors.

PubMed

Fucile, Sergio; Sucapane, Antonietta; Eusebi, Fabrizio

2006-04-01

We investigated the functional properties of rat alpha9 and alpha9alpha10 nicotinic acetylcholine receptors (nAChRs) expressed by transient transfection in the rat GH4C1 cell line, using both Ca(2+) imaging and whole-cell recording. Acute applications of ACh generated short-delay fast-rising and quick-decaying Ca(2+) transients, suppressed in Ca(2+)-free medium and invariably accompanied by the activation of whole-cell inward currents. The mean amplitude of ACh-induced currents was as small as -16 pA in alpha9 subunit cDNA-transfected GH4C1 cells (alpha9-GH4C1), while they were much larger (range: -150 to -300 pA) in alpha9alpha10 subunit cDNAs-transfected GH4C1 cells (alpha9alpha10-GH4C1). Currents were not activated by nicotine, were blocked by methyllycaconitine and were ACh concentration-dependent. Because the Ca(2+) permeability of alpha9-containing nAChRs has been estimated in immortalized cochlear UB/OC-2 mouse cells, we also characterized the ACh-induced responses in these cells. Unlike alpha9- and alpha9alpha10-GH4C1 cells, UB/OC-2 cells responded to ACh with both long-delay methyllycaconitine-insensitive whole-cell currents and long-lasting Ca(2+) transients, the latter being detected in the absence of Ca(2+) in the extracellular medium and being suppressed by the Ca(2+)-ATPase inhibitor thapsigargin, known to deplete IP(3)-sensitive stores. These results indicated the involvement of muscarinic nAChRs and the lack of functional ACh-gated receptor channels in UB/OC-2 cells. Thus, we measured the fractional Ca(2+) current (P(f), i.e. the percentage of total current carried by Ca(2+) ions) in alpha9alpha10-GH4C1, obtaining a P(f) value of 22 +/- 4%; this is the largest value estimated to date for a ligand-gated receptor channel. The physiological role played by Ca(2+) entry through alpha9-containing nAChRs gated by ACh is discussed.

Effect of salivary gland adenocarcinoma cell-derived alpha-N-acetylgalactosaminidase on the bioactivity of macrophage activating factor.

PubMed

Matsuura, Takashi; Uematsu, Takashi; Yamaoka, Minoru; Furusawa, Kiyofumi

2004-03-01

The aim of this study was to clarify the effects of alpha-N-acetylgalactosaminidase (alpha-NaGalase) produced by human salivary gland adenocarcinoma (SGA) cells on the bioactivity of macrophage-activating factor (GcMAF). High exo-alpha-NaGalase activity was detected in the SGA cell line HSG. HSG alpha-NaGalase had both exo- and endo-enzyme activities, cleaving the Gal-GalNAc and GalNAc residues linked to Thr/Ser but not releasing the [NeuAc2-6]GalNac residue. Furthermore, GcMAF enzymatically prepared from the Gc protein enhanced the superoxide-generation capacity and phagocytic activity of monocytes/macrophages. However, GcMAF treated with purified alpha-NaGalase did not exhibit these effects. Thus, HSG possesses the capacity to produce larger quantities of alpha-NaGalase, which inactivates GcMAF produced from Gc protein, resulting in reduced phagocytic activity and superoxide-generation capacity of monocytes/macrophages. The present data strongly suggest that HSG alpha-NaGalase acts as an immunodeficiency factor in cancer patients.

Analysis of the two-peptide bacteriocins lactococcin G and enterocin 1071 by site-directed mutagenesis.

PubMed

Oppegård, Camilla; Fimland, Gunnar; Thorbaek, Lisbeth; Nissen-Meyer, Jon

2007-05-01

The two peptides (Lcn-alpha and Lcn-beta) of the two-peptide bacteriocin lactococcin G (Lcn) were changed by stepwise site-directed mutagenesis into the corresponding peptides (Ent-alpha and Ent-beta) of the two-peptide bacteriocin enterocin 1071 (Ent), and the potencies and specificities of the various hybrid constructs were determined. Both Lcn and, to a lesser extent, Ent were active against all the tested lactococcal strains, but only Ent was active against the tested enterococcal strains. The two bacteriocins thus differed in their relative potencies to various target cells, despite their sequence similarities. The hybrid combination Lcn-alpha+Ent-beta had low potency against all strains tested, indicating that these two peptides do not interact optimally. The reciprocal hybrid combination (i.e., Ent-alpha+Lcn-beta), in contrast, was highly potent, indicating that these two peptides may form a functional antimicrobial unit. In fact, this hybrid combination (Ent-alpha+Lcn-beta) was more potent against lactococcal strains than wild-type Ent was (i.e., Ent-alpha+Ent-beta), but it was inactive against enterococcal strains (in contrast to Ent but similar to Lcn). The observation that Ent-alpha is more active against lactococci in combination with Lcn-beta and more active against enterococci in combination with Ent-beta suggests that the beta peptide is an important determinant of target cell specificity. Especially the N-terminal residues of the beta peptide seem to be important for specificity, since Ent-alpha combined with an Ent-beta variant with Ent-to-Lcn mutations at positions 1 to 4, 7, 9, and 10 was >150-fold less active against enterococcal strains but one to four times more active against lactococcal strains than Ent-alpha+Ent-beta. Moreover, Ent-to-Lcn single-residue mutations in the region spanning residues 1 to 7 in Ent-beta had a more detrimental effect on the activity against enterococci than on that against lactococcal strains. Of the single-residue mutations made in the N-terminal region of the alpha peptide, the Ent-to-Lcn mutations N8Q and P12R in Ent-alpha influenced specificity, as follows: the N8Q mutation had no effect on activity against tested enterococcal strains but increased the activity 2- to 4-fold against the tested lactococcal strains, and the P12R mutation reduced the activity >150-fold and only approximately 2-fold against enterococcal and lactococcal strains, respectively. Changing residues in the C-terminal half/part of the Lcn peptides (residues 20 to 39 and 25 to 35 in Lcn-alpha and Lcn-beta, respectively) to those found in the corresponding Ent peptides did not have a marked effect on the activity, but there was an approximately 10-fold or greater reduction in the activity upon also introducing Lcn-to-Ent mutations in the mid-region (residues 8 to 19 and 9 to 24 in Lcn-alpha and Lcn-beta, respectively). Interestingly, the Lcn-to-Ent F19L+G20A mutation in an Lcn-Ent-beta hybrid peptide was more detrimental when the altered peptide was combined with Lcn-alpha (>10-fold reduction) than when it was combined with Ent-alpha ( approximately 2-fold reduction), suggesting that residues 19 and 20 (which are part of a GXXXG motif) in the beta peptide may be involved in a specific interaction with the cognate alpha peptide. It is also noteworthy that the K2P and A7P mutations in Lcn-beta reduced the activity only approximately 2-fold, suggesting that the first seven residues in the beta peptides do not form an alpha-helix.

Spontaneous cortical DC-potential shifts: modulation stereotypy; relationships to higher EEG-frequencies.

PubMed

Etlinger, S C; Guttmann, G; Bauer, H

1986-07-01

A description of scalp-recorded, spontaneous, cerebral DC-potential shifts is given independent of other variables (shift stereotypy), in relationship to higher frequencies (theta, alpha 1, alpha 2: 4-13 Hz) and as analyzed pairwise across the median sagittal line (Fz, Cz, Pz) separately according to frequency and condition (relaxation and moderate mental load). Spontaneous DC-shifts are shown to behave unpredictably. Whether measured jointly (up to triads) or as dyad and triad context entropy, the frontal DC-shifts are calculated as being random, whereby their definition as such within the context of the Principle Component Analysis is supported by the analysis of longitudinal registrations. Cross-correlation analysis of the cerebral slow potential's relationship to each of the higher frequencies (theta, alpha 1, alpha 2) reveals it to be highly independent, the highest correlation accounting for merely 11% of the common variance, the average being 9% (R congruent to 0.3). By matching the conjoint activity of the DC-potential between Fz-Cz, Cz-Pz, and Fz-Pz to that of theta, alpha 1, alpha 2 at the same paired sites, the DC-activity is shown to be operating at higher levels of synchronous activity than the higher frequencies, regardless of pairing and/or condition, although the general level of synchronous activity (DC, theta, alpha 1, alpha 2) is remarkably high along the median sagittal line, 75% of the correlation averages of all analysis-pairings being above 0.60.

Lead acetate induces EGFR activation upstream of SFK and PKC{alpha} linkage to the Ras/Raf-1/ERK signaling

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

Wang, C.-Y.; Wang, Y.-T.; Tzeng, D.-W.

2009-03-01

Lead acetate (Pb), a probable human carcinogen, can activate protein kinase C (PKC) upstream of extracellular signal-regulated kinase 1 and 2 (ERK1/2). Yet, it remains unclear whether Pb activation of PKC {yields} ERK1/2 involves receptor/non-receptor tyrosine kinases and the Ras signaling transducer. Here we demonstrate a novel mechanism elicited by Pb for transmitting ERK1/2 signaling in CL3 human non-small-cell lung adenocarcinoma cells. Pb induction of higher steady-state levels of Ras-GTP was essential for increasing phospho-Raf-1{sup S338} and phospho-ERK1/2. Pre-treatment of the cells with a conventional PKC inhibitor Goe6976 or depleting PKC{alpha} using specific small interfering RNA blocked Pb induction ofmore » Ras-GTP. Pb also activated cellular tyrosine kinases. Specific pharmacological inhibitors, PD153035 for epidermal growth factor receptor (EGFR) and SU6656 for Src family tyrosine kinases (SFK), but not AG1296 for platelet-derived growth factor receptor, could suppress the Pb-induced tyrosine kinases, PKC{alpha}, Ras-GTP, phospho-Raf-1{sup S338} and phospho-ERK1/2. Furthermore, phosphorylation of tyrosines on the EGFR multiple autophosphorylation sites and the conserved SFK autophosphorylation site occurred during exposure of cells to Pb for 1-5 min and 5-30 min, respectively. Intriguingly, Pb activation of EGFR required the intrinsic kinase activity but not dimerization of the receptor. Inhibition of SFK or PKC{alpha} activities did not affect EGFR phosphorylation, while knockdown of EGFR blocked SFK phosphorylation and PKC{alpha} activation following Pb. Together, these results indicate that immediate activation of EGFR in response to Pb is obligatory for activation of SFK and PKC{alpha} and subsequent the Ras-Raf-1-MKK1/2-ERK1/2 signaling cascade.« less

Temporal expression of the human alcohol dehydrogenase gene family during liver development correlates with differential promoter activation by hepatocyte nuclear factor 1, CCAAT/enhancer-binding protein alpha, liver activator protein, and D-element-binding protein.

PubMed Central

van Ooij, C; Snyder, R C; Paeper, B W; Duester, G

1992-01-01

The human class I alcohol dehydrogenase (ADH) gene family consists of ADH1, ADH2, and ADH3, which are sequentially activated in early fetal, late fetal, and postnatal liver, respectively. Analysis of ADH promoters revealed differential activation by several factors previously shown to control liver transcription. In cotransfection assays, the ADH1 promoter, but not the ADH2 or ADH3 promoter, was shown to respond to hepatocyte nuclear factor 1 (HNF-1), which has previously been shown to regulate transcription in early liver development. The ADH2 promoter, but not the ADH1 or ADH3 promoter, was shown to respond to CCAAT/enhancer-binding protein alpha (C/EBP alpha), a transcription factor particularly active during late fetal liver and early postnatal liver development. The ADH1, ADH2, and ADH3 promoters all responded to the liver transcription factors liver activator protein (LAP) and D-element-binding protein (DBP), which are most active in postnatal liver. For all three promoters, the activation by LAP or DBP was higher than that seen by HNF-1 or C/EBP alpha, and a significant synergism between C/EBP alpha and LAP was noticed for the ADH2 and ADH3 promoters when both factors were simultaneously cotransfected. A hierarchy of ADH promoter responsiveness to C/EBP alpha and LAP homo- and heterodimers is suggested. In all three ADH genes, LAP bound to the same four sites previously reported for C/EBP alpha (i.e., -160, -120, -40, and -20 bp), but DBP bound strongly only to the site located at -40 bp relative to the transcriptional start. Mutational analysis of ADH2 indicated that the -40 bp element accounts for most of the promoter regulation by the bZIP factors analyzed. These studies suggest that HNF-1 and C/EBP alpha help establish ADH gene family transcription in fetal liver and that LAP and DBP help maintain high-level ADH gene family transcription in postnatal liver. Images PMID:1620113

Activation of the Serotonin Pathway is Associated with Poor Outcome in COPD Exacerbation: Results of a Long-Term Cohort Study.

PubMed

Meier, Marc A; Ottiger, Manuel; Vögeli, Alaadin; Steuer, Christian; Bernasconi, Luca; Thomann, Robert; Christ-Crain, Mirjam; Henzen, Christoph; Hoess, Claus; Zimmerli, Werner; Huber, Andreas; Mueller, Beat; Schuetz, Philipp

2017-06-01

Indoleamine 2,3-dioxygenase (IDO) metabolizes tryptophan to kynurenine. An increase of its activity is associated with severity in patients with pneumonia. In chronic obstructive pulmonary disease (COPD) patients, an elevation of serotonin has been reported. Experimental models showed that cigarette smoke inhibits monoamine oxidase (MAO) leading to higher levels of serotonin. We investigated the prognostic ability of tryptophan, serotonin, kynurenine, IDO, and tryptophan hydroxylase (TPH) to predict short- and long-term outcomes in patients with a COPD exacerbation. We measured tryptophan, serotonin, and kynurenine on admission plasma samples in patients with a COPD exacerbation from a previous trial by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). IDO and TPH were calculated as ratios of kynurenine over tryptophan, and serotonin over tryptophan, respectively. We studied their association with parameters measured in clinical routine at emergency department admission representing inflammation (C-reactive protein [CRP]), infection (procalcitonin [PCT]), oxygenation (SpO 2 ), as well as patients' clinical outcome, confirmed by structured phone interviews. Mortality in the 149 included patients was 53.7% within six years of follow-up. While IDO activity showed strong positive correlations, tryptophan was negatively correlated with CRP and PCT. For 30-day adverse outcome defined as death and/or intensive care unit (ICU) admission, a multivariate regression analysis adjusted for age and comorbidities found strong associations for IDO activity (adjusted odds ratios of 31.4 (95%CI 1.1-857), p = 0.041) and TPH (adjusted odds ratios 27.0 (95%CI 2.2-327), p = 0.010). TPH also showed a significant association with mortality at 18 months, (hazard ratio 2.61 (95%CI 1.2-5.8), p = 0.020). In hospitalized patients with a COPD exacerbation, higher IDO and TPH activities independently predicted adverse short-term outcomes and TPH levels were also predictive of 18-month mortality. Whether therapeutic modulation of the serotonin pathway has positive effects on outcome needs further investigation.

Lack of NG2 exacerbates neurological outcome and modulates glial responses after traumatic brain injury.

PubMed

Huang, Changsheng; Sakry, Dominik; Menzel, Lutz; Dangel, Larissa; Sebastiani, Anne; Krämer, Tobias; Karram, Khalad; Engelhard, Kristin; Trotter, Jacqueline; Schäfer, Michael K E

2016-04-01

Traumatic brain injury (TBI) is a major cause of death and disability. The underlying pathophysiology is characterized by secondary processes including neuronal death and gliosis. To elucidate the role of the NG2 proteoglycan we investigated the response of NG2-knockout mice (NG2-KO) to TBI. Seven days after TBI behavioral analysis, brain damage volumetry and assessment of blood brain barrier integrity demonstrated an exacerbated response of NG2-KO compared to wild-type (WT) mice. Reactive astrocytes and expression of the reactive astrocyte and neurotoxicity marker Lcn2 (Lipocalin-2) were increased in the perilesional brain tissue of NG2-KO mice. In addition, microglia/macrophages with activated morphology were increased in number and mRNA expression of the M2 marker Arg1 (Arginase 1) was enhanced in NG2-KO mice. While TBI-induced expression of pro-inflammatory cytokine genes was unchanged between genotypes, PCR array screening revealed a marked TBI-induced up-regulation of the C-X-C motif chemokine 13 gene Cxcl13 in NG2-KO mice. CXCL13, known to attract immune cells to the inflamed brain, was expressed by activated perilesional microglia/macrophages seven days after TBI. Thirty days after TBI, NG2-KO mice still exhibited more pronounced neurological deficits than WT mice, up-regulation of Cxcl13, enhanced CD45+ leukocyte infiltration and a relative increase of activated Iba-1+/CD45+ microglia/macrophages. Our study demonstrates that lack of NG2 exacerbates the neurological outcome after TBI and associates with abnormal activation of astrocytes, microglia/macrophages and increased leukocyte recruitment to the injured brain. These findings suggest that NG2 may counteract neurological deficits and adverse glial responses in TBI. © 2015 Wiley Periodicals, Inc.

Analysis of protein levels of 24 cytokines in scrapie agent-infected brain and glial cell cultures from mice differing in prion protein expression levels.

PubMed

Tribouillard-Tanvier, Déborah; Striebel, James F; Peterson, Karin E; Chesebro, Bruce

2009-11-01

Activation of microglia and astroglia is seen in many neurodegenerative diseases including prion diseases. Activated glial cells produce cytokines as a protective response against certain pathogens and as part of the host inflammatory response to brain damage. In addition, cytokines might also exacerbate tissue damage initiated by other processes. In the present work using multiplex assays to analyze protein levels of 24 cytokines in scrapie agent-infected C57BL/10 mouse brains, we observed elevation of CCL2, CCL5, CXCL1, CXCL10, granulocyte-macrophage colony-stimulating factor (GM-CSF), gamma interferon (IFN-gamma), interleukin 1alpha (IL-1alpha), IL-1beta, IL-6, and IL-12p40. Scrapie agent-infected wild-type mice and transgenic mice expressing anchorless prion protein (PrP) had similar cytokine responses in spite of extensive differences in neuropathology. Therefore, these responses may be primarily a reaction to brain damage induced by prion infection rather than specific inducers of a particular type of pathology. To study the roles of astroglia and microglia in these cytokine responses, primary glial cultures were exposed to scrapie agent-infected brain homogenates. Microglia produced only IL-12p40 and CXCL10, whereas astroglia produced these cytokines plus CCL2, CCL3, CCL5, CXCL1, G-CSF, IL-1beta, IL-6, IL-12p70, and IL-13. Glial cytokine responses from wild-type mice and transgenic mice expressing anchorless PrP differed only slightly, but glia from PrP-null mice produced only IL-12p40, indicating that PrP expression was required for scrapie agent induction of other cytokines detected. The difference in cytokine response between microglia and astroglia correlated with 20-fold-higher levels of PrP expression in astroglia versus microglia, suggesting that high-level PrP expression on astroglia might be important for induction of certain cytokines.

RORα switches transcriptional mode of ERRγ that results in transcriptional repression of CYP2E1 under ethanol-exposure

PubMed Central

Han, Yong-Hyun; Kim, Don-Kyu; Na, Tae-Young; Ka, Na-Lee; Choi, Hueng-Sik; Lee, Mi-Ock

2016-01-01

Increased cytochrome P450 2E1 (CYP2E1) expression is the main cause of oxidative stress, which exacerbates alcoholic liver diseases (ALDs). Estrogen-related receptor gamma (ERRγ) induces CYP2E1 expression and contributes to enhancing alcohol-induced liver injury. Retinoic acid-related orphan receptor alpha (RORα) has antioxidative functions; however, potential cross-talk between ERRγ and RORα in the regulation of CYP2E1 has not been studied. We report that RORα suppressed ERRγ-mediated CYP2E1 expression. A physical interaction of RORα with ERRγ at the ERRγ−response element in the CYP2E1 promoter was critical in this suppression. At this site, coregulator recruitment of ERRγ was switched from coactivator p300 to the nuclear receptor corepressor 1 in the presence of RORα. Cross-talk between ERRγ and RORα was demonstrated in vivo, in that administration of JC1–40, a RORα activator, significantly decreased both CYP2E1 expression and the signs of liver injury in ethanol-fed mice, and this was accompanied by coregulator switching. Thus, this non-classical RORα pathway switched the transcriptional mode of ERRγ, leading to repression of alcohol-induced CYP2E1 expression, and this finding may provide a new therapeutic strategy against ALDs. PMID:26464440

Influence of thyroid status on hepatic alpha 1-adrenoreceptor responsiveness.

PubMed

Daza, F J; Parrilla, R; Martín-Requero, A

1997-12-01

The present work aimed to elucidate the influence of thyroid functional status on the alpha 1-adrenoreceptor-induced activation of hepatic metabolic functions. The experiments were performed in either a nonrecirculating liver perfusion system featuring continuous monitoring of portal pressure, PO2, pCa, and pH, or isolated hepatocytes from euthyroid, hyperthyroid, and hypothyroid rats. Hypothyroidism decreased the alpha 1-adrenergic stimulation of respiration, glycogen breakdown, and gluconeogenesis. These effects were accompanied by a decreased intracellular Ca2+ mobilization corroborating that those processes are regulated by the Ca(2+)-dependent branch of the alpha 1-adrenoreceptor signaling pathway. Moreover, in hyperthyroid rats the alpha 1-adrenergic-induced increase in cytosolic Ca2+ was enhanced, and glucose synthesis or mobilization was not altered. The thyroid status influenced neither the alpha 1-adrenergic stimulation of vascular smooth muscle contraction nor the alpha 1-agonist-induced intracellular alkalinization and protein kinase C (PKC) activation. Thus the distinct impairment of the Ca(2+)-dependent branch of the alpha 1-adrenoreceptor signaling pathway by thyroid status provides a useful tool to investigate the role played by each signaling pathway, Ca2+ or PKC, in controlling hepatic functions.

Trypanocidal constituents in plants 6. 1) Minor withanolides from the aerial parts of Physalis angulata.

PubMed

Abe, Fumiko; Nagafuji, Shinya; Okawa, Masafumi; Kinjo, Junei

2006-08-01

Further study of the methanol extract of the aerial parts of Physalis angulata (Solanaceae) resulted in the isolation of new withanolides, designated physagulins L, M and N, together with known withanolide, physagulin D and flavonol glycoside, quercetin 3-O-rhamnosyl-(1-->6)-galactoside. The chemical structures of these new withanolides were elucidated by detailed spectroscopic analyses to be (20R,22R)-15alpha-acetoxy-5alpha,6beta,14beta,17beta,27-pentahydroxy-1-oxo-witha-2, 24-dienolide, (20S,22S)-15alpha-acetoxy-5alpha,6beta,14alpha,23beta-tetrahydroxy-1-oxo-witha-2,16,24-trienolide and (20S,22R)-15alpha-acetoxy-5beta,6beta-epoxy-14alpha-hydoxy-3beta-methoxy-1-oxo-witha-16,24-dienolide, respectively. All these compounds showed weak trypanocidal activity against trypomastigotes, an infectious form of Trypanosoma cruzi, the etiologic agent for Chagas' disease. Withanolides obtained in the previous paper showed considerable trypanocidal activity, suggesting the structure-activity relationships.

Pharmacological treatment optimization for stable chronic obstructive pulmonary disease. Proposals from the Société de Pneumologie de Langue Française.

PubMed

Zysman, M; Chabot, F; Devillier, P; Housset, B; Morelot-Panzini, C; Roche, N

2016-12-01

The Société de Pneumologie de Langue Française proposes a decision algorithm on long-term pharmacological COPD treatment. A working group reviewed the literature published between January 2009 and May 2016. This document lays out proposals and not guidelines. It only focuses on pharmacological treatments except vaccinations, smoking cessation treatments and oxygen therapy. Any COPD diagnosis, based on pulmonary function tests, should lead to recommend smoking cessation, vaccinations, physical activity, pulmonary rehabilitation in case of activity limitation, and short-acting bronchodilators. Symptoms like dyspnea and exacerbations determine the therapeutic choices. In case of daily dyspnea and/or exacerbations, a long-acting bronchodilator should be suggested (beta-2 agonist, LABA or anticholinergics, LAMA). A clinical and lung function reevaluation is suggested 1 to 3 months after any treatment modification and every 3-12 months according to the severity of the disease. In case of persisting dyspnea, a fixed dose LABA+LAMA combination improves pulmonary function (FEV1), quality of life, dyspnea and decreases exacerbations without increasing side effects. In case of frequent exacerbations and a FEV1≤70%, a fixed dose long-acting bronchodilator combination or a LABA+ inhaled corticosteroids (ICS) combination can be proposed. A triple combination (LABA+LAMA+ICS) is indicated when exacerbations persist despite one of these combinations. Dyspnea in spite of a bronchodilator combination or exacerbations in spite of a triple combination should lead to consider other pharmacological treatments (theophylline if dyspnea, macrolides if exacerbations, low-dose opioids if refractory dyspnea). Copyright © 2016. Published by Elsevier Masson SAS.

Intermittent hypoxia activates peptidylglycine alpha-amidating monooxygenase in rat brain stem via reactive oxygen species-mediated proteolytic processing.

PubMed

Sharma, Suresh D; Raghuraman, Gayatri; Lee, Myeong-Seon; Prabhakar, Nanduri R; Kumar, Ganesh K

2009-01-01

Intermittent hypoxia (IH) associated with sleep apneas leads to cardiorespiratory abnormalities that may involve altered neuropeptide signaling. The effects of IH on neuropeptide synthesis have not been investigated. Peptidylglycine alpha-amidating monooxygenase (PAM; EC 1.14.17.3) catalyzes the alpha-amidation of neuropeptides, which confers biological activity to a large number of neuropeptides. PAM consists of O(2)-sensitive peptidylglycine alpha-hydroxylating monooxygenase (PHM) and peptidyl-alpha-hydroxyglycine alpha-amidating lyase (PAL) activities. Here, we examined whether IH alters neuropeptide synthesis by affecting PAM activity and, if so, by what mechanisms. Experiments were performed on the brain stem of adult male rats exposed to IH (5% O(2) for 15 s followed by 21% O(2) for 5 min; 8 h/day for up to 10 days) or continuous hypoxia (0.4 atm for 10 days). Analysis of brain stem extracts showed that IH, but not continuous hypoxia, increased PHM, but not PAL, activity of PAM and that the increase of PHM activity was associated with a concomitant elevation in the levels of alpha-amidated forms of substance P and neuropeptide Y. IH increased the relative abundance of 42- and 35-kDa forms of PHM ( approximately 1.6- and 2.7-fold, respectively), suggesting enhanced proteolytic processing of PHM, which appears to be mediated by an IH-induced increase of endoprotease activity. Kinetic analysis showed that IH increases V(max) but has no effect on K(m). IH increased generation of reactive oxygen species in the brain stem, and systemic administration of antioxidant prevented IH-evoked increases of PHM activity, proteolytic processing of PHM, endoprotease activity, and elevations in substance P and neuropeptide Y amide levels. Taken together, these results demonstrate that IH activates PHM in rat brain stem via reactive oxygen species-dependent posttranslational proteolytic processing and further suggest that PAM activation may contribute to IH-mediated peptidergic neurotransmission in rat brain stem.

N-substituted imidazolines and ethylenediamines and their action on alpha- and beta-adrenergic receptors.

PubMed

Hamada, A; Yaden, E L; Horng, J S; Ruffolo, R R; Patil, P N; Miller, D D

1985-09-01

A series of N-substituted imidazolines and ethylenediamines were synthesized and examined for their activity in alpha- and beta-adrenergic systems. The length of the intermediate side chain between the catechol and imidazoline ring or the amine of the ethylenediamine segment was shown to affect the adrenergic activity. N-[2-(3,4-Dihydroxyphenyl)ethyl]imidazoline hydrochloride (2) and N-[2-(3,4-dihydroxyphenyl)ethyl]ethylenediamine dihydrochloride (4), both with two methylene groups between the catechol and amine segment, were found to be somewhat selective for alpha 2-adrenergic receptors while 1-(3,4-dihydroxybenzyl)imidazoline hydrochloride (1) and N-2-(3,4-dihydroxybenzyl)ethylenediamine dihydrochloride (3), both with one methylene group between the catechol and amine segment, were more selective for alpha1-adrenergic receptors in a pithed rat model. Of the four compounds examined, only compound 2 showed significant direct activity on beta1- and beta2-adrenergic receptors.

Alpha-2 adrenergic activity of bromocriptine and quinpirole in chicken pineal gland. Effects on melatonin synthesis and ( sup 3 H)rauwolscine binding

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

Zawilska, J.; Iuvone, P.M.

In the pineal gland and retina of chickens, serotonin N-acetyl-transferase (NAT) activity and melatonin content are modulated by different receptors, alpha-2 adrenergic receptors in pineal gland and D2-dopamine receptors in retina. The effect of two D2-dopamine receptor agonists, bromocriptine and quinpirole (LY 171555), on melatonin synthesis in these tissues was investigated. Systemic administrations of bromocriptine and quinpirole decreased nocturnal NAT activity and melatonin content of both pineal gland and retina. Bromocriptine was equipotent in the two tissues, whereas quinpirole was approximately 100-fold more potent in retina than in pineal gland. In pineal gland, the suppressive effects of bromocriptine and quinpirolemore » on NAT activity were blocked by yohimbine, a selective alpha-2 adrenergic receptor antagonist, but not by spiperone, a D2-dopamine receptor antagonist. In contrast, bromocriptine- and quinpirole-induced decreases of the enzyme activity in retina were antagonized by spiperone, and not affected by yohimbine. The nocturnal increase of NAT activity of pineal glands in vitro was inhibited with an order of potency clonidine greater than bromocriptine greater than quinpirole. Additionally, bromocriptine and quinpirole displaced the specific binding of (3H)rauwolscine, an alpha-2 adrenergic receptor antagonist, to membranes from chicken pineal gland, with potencies comparable to those observed for inhibition of NAT activity in vitro. It is suggested that bromocriptine and quinpirole, in addition to their D2-dopaminergic activity, can stimulate alpha-2 adrenergic receptors in pineal gland of chicken.« less

The liver glucose-6-phosphatase of intact microsomes is inhibited and displays sigmoid kinetics in the presence of alpha-ketoglutarate-magnesium and oxaloacetate-magnesium chelates.

PubMed

Mithieux, G; Vega, F V; Riou, J P

1990-11-25

We have recently shown that the Ca.EGTA and Mg.EDTA complexes, but not free Ca2+ or Mg2+, inhibit the liver glucose-6-phosphatase (Mithieux, G., Vega, F. V., Beylot, M., and Riou, J. P. (1990) J. Biol. Chem. 265, 7257-7259). In this work, we report that, when complexed with Mg2+, two endogenous dicarboxylic keto acids (alpha-ketoglutarate (alpha-KG) and oxaloacetate (OAA] inhibit the glucose-6-phosphatase activity at low concentrations of substrate. This phenomenon is specific for complexes of Mg2+ with alpha-KG and OAA since 1) the complexes of Mg2+ with a number of other di- or tricarboxylic acids having high structural analogy with alpha-KG and OAA (oxalate, malate, succinate, citrate, aspartate, and glutamate) do not inhibit the glucose-6-phosphatase activity and 2) the Ca.alpha-KG and Ca.OAA chelates do not inhibit the glucose-6-phosphatase activity. In the presence of Mg.alpha-KG or Mg.OAA chelates, the enzyme displays sigmoid kinetics; the Hanes plots deviate from linearity, indicating the positive cooperative dependence of the velocity upon the substrate concentration. Hill coefficients (equal to 1 in the absence of the chelates) of 1.23 and 1.33 have been determined in the presence of Mg.alpha-KG and Mg.OAA complexes, respectively. The disruption of microsomal integrity by detergents abolishes the effect of Mg.alpha-KG and Mg.OAA, suggesting that the magnesium chelates inhibit the translocase component of the glucose-6-phosphatase system.

P2X7-Regulated Protection from Exacerbations and Loss of Control Is Independent of Asthma Maintenance Therapy

PubMed Central

Manthei, David M.; Seibold, Max A.; Ahn, Kwangmi; Bleecker, Eugene; Boushey, Homer A.; Calhoun, William J.; Castro, Mario; Chinchili, Vernon M.; Fahy, John V.; Hawkins, Greg A.; Icitovic, Nicolina; Israel, Elliot; Jarjour, Nizar N.; King, Tonya; Kraft, Monica; Lazarus, Stephen C.; Lehman, Erik; Martin, Richard J.; Meyers, Deborah A.; Peters, Stephen P.; Sheerar, Dagna; Shi, Lei; Sutherland, E. Rand; Szefler, Stanley J.; Wechsler, Michael E.; Sorkness, Christine A.; Lemanske, Robert F.

2013-01-01

Rationale: The function of the P2X7 nucleotide receptor protects against exacerbation in people with mild-intermittent asthma during viral illnesses, but the impact of disease severity and maintenance therapy has not been studied. Objectives: To evaluate the association between P2X7, asthma exacerbations, and incomplete symptom control in a more diverse population. Methods: A matched P2RX7 genetic case-control was performed with samples from Asthma Clinical Research Network trial participants enrolled before July 2006, and P2X7 pore activity was determined in whole blood samples as an ancillary study to two trials completed subsequently. Measurements and Main Results: A total of 187 exacerbations were studied in 742 subjects, and the change in asthma symptom burden was studied in an additional 110 subjects during a trial of inhaled corticosteroids (ICS) dose optimization. African American carriers of the minor G allele of the rs2230911 loss-of-function single nucleotide polymorphism were more likely to have a history of prednisone use in the previous 12 months, with adjustment for ICS and long-acting β2-agonists use (odds ratio, 2.7; 95% confidence interval, 1.2–6.2; P = 0.018). Despite medium-dose ICS, attenuated pore function predicted earlier exacerbations in incompletely controlled patients with moderate asthma (hazard ratio, 3.2; confidence interval, 1.1–9.3; P = 0.033). After establishing control with low-dose ICS in patients with mild asthma, those with attenuated pore function had more asthma symptoms, rescue albuterol use, and FEV1 reversal (P < 0.001, 0.03, and 0.03, respectively) during the ICS adjustment phase. Conclusions: P2X7 pore function protects against exacerbations of asthma and loss of control, independent of baseline severity and the maintenance therapy. PMID:23144325

Comparative study on cytogenetic damage induced by homo-aza-steroidal esters in human lymphocytes.

PubMed

Mourelatos, D; Papageorgiou, A; Boutis, L; Catsoulacos, P

1995-02-01

The effect of P[N,N-bis(2-chloroethyl)amino]phenylacetate esters of 3 beta-hydroxy-N-methyl-17 alpha-aza-D-homo-5 alpha-androstan-17-one (compound 3) and 3 beta-hydroxy-17 alpha-aza-D-homo-5 alpha-androstane (compound 2) on sister-chromatid exchange (SCE) frequencies and on human lymphocytes proliferation kinetics was studied. The results are compared with those of the P[N,N-bis(2-chloroethyl)amino]phenylacetate esters of 3 beta-hydroxy-17 alpha-aza-D-homo-5 alpha-androstan-17-one (compound 1). All compounds were found to be active in inducing markedly increased SCE rates and cell division delays. A correlation between potency for SCE induction, effectiveness in cell division delay and previously established antitumour activity of these compounds was observed.

Alpha-7 nicotinic acetylcholine receptor agonist treatment reduces neuroinflammation, oxidative stress, and brain injury in mice with ischemic stroke and bone fracture.

PubMed

Han, Zhenying; Li, Li; Wang, Liang; Degos, Vincent; Maze, Mervyn; Su, Hua

2014-11-01

Bone fracture at the acute stage of stroke exacerbates stroke injury by increasing neuroinflammation. We hypothesize that activation of α-7 nicotinic acetylcholine receptor (α-7 nAchR) attenuates neuroinflammation and oxidative stress, and reduces brain injury in mice with bone fracture and stroke. Permanent middle cerebral artery occlusion (pMCAO) was performed in C57BL/6J mice followed by tibia fracture 1 day later. Mice were treated with 0.8 mg/kg PHA 568487 (PHA, α-7 nAchR-specific agonist), 6 mg/kg methyllycaconitine (α-7 nAchR antagonist), or saline 1 and 2 days after pMCAO. Behavior was tested 3 days after pMCAO. Neuronal injury, CD68(+) , M1 (pro-inflammatory) and M2 (anti-inflammatory) microglia/macrophages, phosphorylated p65 component of nuclear factor kappa b in microglia/macrophages, oxidative and anti-oxidant gene expression were quantified. Compared to saline-treated mice, PHA-treated mice performed better in behavioral tests, had fewer apoptotic neurons (NeuN(+) TUNEL(+) ), fewer CD68(+) and M1 macrophages, and more M2 macrophages. PHA increased anti-oxidant gene expression and decreased oxidative stress and phosphorylation of nuclear factor kappa b p65. Methyllycaconitine had the opposite effects. Our data indicate that α-7 nAchR agonist treatment reduces neuroinflammation and oxidative stress, which are associated with reduced brain injury in mice with ischemic stroke plus tibia fracture. Bone fracture at the acute stage of stroke exacerbates neuroinflammation, oxidative stress, and brain injury, and our study has shown that the α-7 nAchR agonist, PHA (PHA 568487), attenuates neuroinflammation, oxidative stress, and brain injury in mice with stroke and bone fracture. Hence, PHA could provide an opportunity to develop a new strategy to reduce brain injury in patients suffering from stroke and bone fracture. © 2014 International Society for Neurochemistry.

Further studies on the quaternary structure of yeast casein kinase II.

PubMed

Szyszka, R; Lopaczyński, W; Gałasiński, W; Grankowski, N; Gasior, E

1986-01-01

Casein kinase type II were isolated by the same procedure, from rat liver, human placenta, Querin carcinoma and yeast, and characterized. The mammalian enzymes were composed of three subunits alpha, alpha' and beta, whereas yeast kinase was composed of two subunits alpha and alpha'. It was shown that the catalytic activity, substrate and phosphate donor specificity, sensitivity to heparin and spermine were the same for all the kinases tested. The results give additional support to the suggestion [1] that the beta subunit is not required for optimal activity and specificity of yeast casein kinase II. The quaternary structure of the yeast enzyme of a molecular weight of approximately 150 000 is proposed as alpha2 alpha'2.

Proteinase-activated receptor-2 stimulates prostaglandin production in keratinocytes: analysis of prostaglandin receptors on human melanocytes and effects of PGE2 and PGF2alpha on melanocyte dendricity.

PubMed

Scott, Glynis; Leopardi, Sonya; Printup, Stacey; Malhi, Namrita; Seiberg, Miri; Lapoint, Randi

2004-05-01

Prostaglandins (PG) are key mediators of diverse functions in the skin and several reports suggest that PG mediate post-inflammatory pigmentary changes through modulation of melanocyte dendricity and melanin synthesis. The proteinase-activated receptor 2 (PAR-2) is important for skin pigmentation because activation of keratinocyte PAR-2 stimulates uptake of melanosomes through phagocytosis in a Rho-dependent manner. In this report, we show that activation of keratinocyte PAR-2 stimulates release of PGE(2) and PGF(2alpha) and that PGE(2) and PGF(2alpha) act as paracrine factors that stimulate melanocyte dendricity. We characterized the expression of the EP and FP receptors in human melanocytes and show that human melanocytes express EP1 and EP3, and the FP receptor, but not EP2 and EP4. Treatment of melanocytes with EP1 and EP3 receptor agonists resulted in increased melanocyte dendricity, indicating that both EP1 and EP3 receptor signaling contribute to PGE(2)-mediated melanocyte dendricity. Certain EP3 receptor subtypes have been shown to increase adenosine 3',5'-cyclic monophosphate (cAMP) through coupling to Gs, whereas EP1 is known to couple to Gq to activate phospholipase C with elevation in Ca(2+). The cAMP/protein kinase A system is known to modulate melanocyte dendrite formation through modulation of Rac and Rho activity. Neither PGF(2alpha) or PGE(2) elevated cAMP in human melanocytes showing that dendricity observed in response to PGE(2) and PGF(2alpha) is cAMP-independent. Our data suggest that PAR-2 mediates cutaneous pigmentation both through increased uptake of melanosomes by keratinocytes, as well as by release of PGE(2) and PGF(2alpha) that stimulate melanocyte dendricity through EP1, EP3, and FP receptors.

Regulation of bovine kidney alpha-ketoglutarate dehydrogenase complex by calcium ion and adenine nucleotides. Effects on S0.5 for alpha-ketoglutarate.

PubMed

Lawlis, V B; Roche, T E

1981-04-28

Regulation of bovine kidney alpha-ketoglutarate dehydrogenase complex by energy-linked metabolites was investigated. Ca2+, ADP, or inorganic phosphate markedly enhanced the activity of the complex, and ATP or, to a lesser extent, GTP decreased the activity of the complex. Initial velocity studies with alpha-ketoglutarate as the varied substrate demonstrated that these modulators induced large changes in S0.5 for alpha-ketoglutarate (based on analysis in Hill plots) with no change in the maximum velocity (as determined by double-reciprocal plots). For all conditions studied, the Hill coefficients were significantly less than 1.0 with slopes that were linear over wide ranges of alpha-ketoglutarate concentrations, indicating negative cooperativity that probably resulted from multiple site-site interactions. Ca2+ (maintained at 10 muM by a Ca2+ buffer) decreased the S0.5 for alpha-ketoglutarate 63-fold (from 25 to 0.40 mM); even in the presence of a positive effector, ADP or phosphate, Ca2+ decreased the S0.5 for alpha-ketoglutarate 7.8- or 28-fold, respectively. Consistent with a mechanism of action dependent of Ca2+, ADP (1.60 mM) or phosphate (20 mM) reduced the S0.5 for alpha-ketoglutarate in the presence of Ca2+ (i.e., 4.5- or 1.67-fold, respectively); however, these effectors elicited larger decreases in S0.5 in the absence of Ca2+ (i.e., 37- or 3.7-fold, respectively). ATP (1.6 mM) increased the S0.5 for alpha-ketoglutarate, and Ca2+ appreciably reduced the effect, lowering the S0.5 98-fold from 66 to 0.67 mM. Thus the activity of the kidney alpha-ketoglutarate dehydrogenase complex is poised to increase as the energy potential in mitochondria declines, and Ca2+ has a pronounced modulatory effect. Comparative studies on bovine heart alpha-ketoglutarate dehydrogenase complex and the effects of varying the ADP/ATP ratio in the presence or absence of Ca2+ or phosphate are also described.

Inhibition of hypoxia inducible factor-1alpha by dihydroxyphenylethanol, a product from olive oil, blocks microsomal prostaglandin-E synthase-1/vascular endothelial growth factor expression and reduces tumor angiogenesis.

PubMed

Terzuoli, Erika; Donnini, Sandra; Giachetti, Antonio; Iñiguez, Miguel A; Fresno, Manuel; Melillo, Giovanni; Ziche, Marina

2010-08-15

2-(3,4-dihydroxyphenil)-ethanol (DPE), a polyphenol present in olive oil, has been found to attenuate the growth of colon cancer cells, an effect presumably related to its anti-inflammatory activity. To further explore the effects of DPE on angiogenesis and tumor growth we investigated the in vivo efficacy of DPE in a HT-29 xenograft model and in vitro activities in colon cancer cells exposed to interleukin-1beta (IL-1beta) and prostaglandin E-2 (PGE-2). DPE (10 mg/kg/day for 14 days) inhibited tumor growth, reducing vessel lumina and blood perfusion to tumor, and diminished expression of hypoxia inducible factor-1alpha (HIF-1alpha), vascular endothelial growth factor (VEGF), and microsomal prostaglandin-E synthase-1 (mPGEs-1). In vitro, DPE (100 mumol/L) neither affected cell proliferation nor induced apoptosis in HT-29 and WiDr cells. DPE prevented the IL-1beta-mediated increase of mPGEs-1 expression and PGE-2 generation, as it did the silencing of HIF-1alpha. Moreover, DPE blocked mPGEs-1-dependent expression of VEGF and inhibited endothelial sprouting induced by tumor cells in a coculture system. PGE-2 triggers a feed-forward loop involving HIF-1alpha, which impinges on mPGEs-1 and VEGF expression, events prevented by DPE via extracellular signal-related kinase 1/2. The reduction of PGE-2 and VEGF levels, caused by DPE, was invariably associated with a marked decrease in HIF-1alpha expression and activity, independent of proteasome activity, indicating that the DPE effects on tumor growth and angiogenesis are dependent on the inhibition of HIF-1alpha translation. We show that the in vivo DPE antitumor effect is associated with anti-inflammatory and antiangiogenic activities resulting from the downregulation of the HIF-1alpha/mPGEs-1/VEGF axis.

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

Arpiainen, Satu; Jaervenpaeae, Sanna-Mari; Manninen, Aki

The nutritional state of organisms and energy balance related diseases such as diabetes regulate the metabolism of xenobiotics such as drugs, toxins and carcinogens. However, the mechanisms behind this regulation are mostly unknown. The xenobiotic-metabolizing cytochrome P450 (CYP) 2A5 enzyme has been shown to be induced by fasting and by glucagon and cyclic AMP (cAMP), which mediate numerous fasting responses. Peroxisome proliferator-activated receptor {gamma} coactivator (PGC)-1{alpha} triggers many of the important hepatic fasting effects in response to elevated cAMP levels. In the present study, we were able to show that cAMP causes a coordinated induction of PGC-1{alpha} and CYP2A5 mRNAsmore » in murine primary hepatocytes. Furthermore, the elevation of the PGC-1{alpha} expression level by adenovirus mediated gene transfer increased CYP2A5 transcription. Co-transfection of Cyp2a5 5' promoter constructs with the PGC-1{alpha} expression vector demonstrated that PGC-1{alpha} is able to activate Cyp2a5 transcription through the hepatocyte nuclear factor (HNF)-4{alpha} response element in the proximal promoter of the Cyp2a5 gene. Chromatin immunoprecipitation assays showed that PGC-1{alpha} binds, together with HNF-4{alpha}, to the same region at the Cyp2a5 proximal promoter. In conclusion, PGC-1{alpha} mediates the expression of CYP2A5 induced by cAMP in mouse hepatocytes through coactivation of transcription factor HNF-4{alpha}. This strongly suggests that PGC-1{alpha} is the major factor mediating the fasting response of CYP2A5.« less

Activated release of membrane-anchored TGF-alpha in the absence of cytosol

PubMed Central

1993-01-01

The ectodomain of proTGF-alpha, a membrane-anchored growth factor, is converted into soluble TGF-alpha by a regulated cellular proteolytic system that recognizes proTGF-alpha via the C-terminal valine of its cytoplasmic tail. In order to define the biochemical components involved in proTGF-alpha cleavage, we have used cells permeabilized with streptolysin O (SLO) that have been extensively washed to remove cytosol. PMA, acting through a Ca(2+)-independent protein kinase C, activates cleavage as efficiently in permeabilized cells as it does in intact cells. ProTGF-alpha cleavage is also stimulated by GTP gamma S through a mechanism whose pharmacological properties suggest the involvement of a heterotrimeric G protein acting upstream of the PMA- sensitive Ca(2+)-independent protein kinase C. Activated proTGF-alpha cleavage is dependent on ATP hydrolysis, appears not to require vesicular traffic, and acts specifically on proTGF-alpha that has reached the cell surface. These results indicate that proTGF-alpha is cleaved from the cell surface by a regulated system whose signaling, recognition, and proteolytic components are retained in cells devoid of cytosol. PMID:8314849

Mechanical stimulation of skeletal muscle increases prostaglandin F2(alpha) synthesis and cyclooxygenase activity by a pertussis toxin sensitive mechanism

NASA Technical Reports Server (NTRS)

Vandenburgh, Herman H.; Shansky, Janet; Solerssi, Rosa; Chromiak, Joseph

1992-01-01

Repetitive mechanical stimulation of differentiated skeletal muscle in tissue culture increases the production of prostaglandin F(sub 2(alpha)), an anabolic stimulator of myofiber growth. Within 4 h of initiating mechanical activity, the activity of cyclooxygenase, a regulatory enzyme in prostaglandin synthesis, was increased 82% (P is less than .005), and this increase was maintained for at least 24 h. Kinetic analysis of the stretch-activated cyclooxygenase indicated a two to three-fold decrease in the enzyme's K(sub m) with no change in V(sub max). The stretch-induced increase in enzymatic activity was not inhibited by cycloheximide, was independent of cellular electrical activity (tetrodotoxin-insensitive), but was prevented by the G protein inhibitor pertussis toxin. Pertussis toxin also inhibited the stretch-induced increases in PGF(sub 2(alpha)) production, and cell growth. It is concluded that stretch of skeletal muscle increases the synthesis of the anabolic modulator PGF(sub 2(alpha)) by a G protein-dependent process which involves activation of cyclooxygenase by a posttranslational mechanism.

Peroxisome proliferator-activated receptor alpha (PPARalpha) agonists down-regulate alpha2-macroglobulin expression by a PPARalpha-dependent mechanism.

EPA Science Inventory

Peroxisome proliferator-activated receptor alpha (PPARα) regulates transcription of genes involved both in lipid and glucose metabolism as well as inflammation. Fibrates are PPARα ligands used to normalize lipid and glucose parameters and exert anti-inflammatory effects. Fibrates...

Fasting induces basolateral uptake transporters of the SLC family in the liver via HNF4alpha and PGC1alpha.

PubMed

Dietrich, Christoph G; Martin, Ina V; Porn, Anne C; Voigt, Sebastian; Gartung, Carsten; Trautwein, Christian; Geier, Andreas

2007-09-01

Fasting induces numerous adaptive changes in metabolism by several central signaling pathways, the most important represented by the HNF4alpha/PGC-1alpha-pathway. Because HNF4alpha has been identified as central regulator of basolateral bile acid transporters and a previous study reports increased basolateral bile acid uptake into the liver during fasting, we hypothesized that HNF4alpha is involved in fasting-induced bile acid uptake via upregulation of basolateral bile acid transporters. In rats, mRNA of Ntcp, Oatp1, and Oatp2 were significantly increased after 48 h of fasting. Protein expression as determined by Western blot showed significant increases for all three transporters 72 h after the onset of fasting. Whereas binding activity of HNF1alpha in electrophoretic mobility shift assays remained unchanged, HNF4alpha binding activity to the Ntcp promoter was increased significantly. In line with this result, we found significantly increased mRNA expression of HNF4alpha and PGC-1alpha. Functional studies in HepG2 cells revealed an increased endogenous NTCP mRNA expression upon cotransfection with either HNF4alpha, PGC-1alpha, or a combination of both. We conclude that upregulation of the basolateral bile acid transporters Ntcp, Oatp1, and Oatp2 in fasted rats is mediated via the HNF4alpha/PGC-1alpha pathway.

Differences in genotoxic activity of alpha-Ni3S2 on human lymphocytes from nickel-hypersensitized and nickel-unsensitized donors.

PubMed

Arrouijal, F Z; Marzin, D; Hildebrand, H F; Pestel, J; Haguenoer, J M

1992-05-01

The genotoxic activity of alpha-Ni3S2 was assessed on human lymphocytes from nickel-hypersensitized (SSL) and nickel-unsensitized (USL) subjects. Three genotoxicity tests were performed: the sister chromatid exchange (SCE) test, the metaphase analysis test and the micronucleus test. (i) The SCE test (3-100 micrograms/ml) showed a weak but statistically significant increase in the number of SCE in both lymphocyte types with respect to controls, USL presenting a slightly higher SCE incidence but only at one concentration. (ii) The metaphase analysis test demonstrated a high dose-dependent clastogenic activity of alpha-Ni3S2 in both lymphocyte types. The frequency of chromosomal anomalies was significantly higher in USL than in SSL for all concentrations applied. (iii) The micronucleus test confirmed the dose-dependent clastogenic activity of alpha-Ni3S2 and the differences already observed between USL and SSL, i.e. the number of cells with micronuclei was statistically higher in USL. Finally, the incorporation study with alpha-63Ni3S2 showed a higher uptake of its solubilized fraction by USL. This allows an explanation of the different genotoxic action of nickel on the two cell types. In this study we demonstrated that hypersensitivity has an influence on the incorporation of alpha-Ni3S2 and subsequently on the different induction of chromosomal aberrations in human lymphocytes.

Renal histopathology in toxicity and carcinogenicity studies with tert-butyl alcohol administered in drinking water to F344 rats: a pathology working group review and re-evaluation.

PubMed

Hard, Gordon C; Bruner, Richard H; Cohen, Samuel M; Pletcher, John M; Regan, Karen S

2011-04-01

An independent Pathology Working Group (PWG) re-evaluated the kidney changes in National Toxicology Program (NTP) toxicology/carcinogenicity studies of tert-butyl alcohol (TBA) in F344/N rats to determine possible mode(s) of action underlying renal tubule tumors in male rats at 2-years. In the 13-week study, the PWG confirmed that the normal pattern of round hyaline droplets in proximal convoluted tubules was replaced by angular droplet accumulation, and identified precursors of granular casts in the outer medulla, changes typical of alpha(2u)-globulin (α(2u)-g) nephropathy. In the 2-year study, the PWG confirmed the NTP observation of increased renal tubule tumors in treated male groups. Linear papillary mineralization, another hallmark of the α(2u)-g pathway was present only in treated male rats. Chronic progressive nephropathy (CPN) was exacerbated in high-dose males and females, with a relationship between advanced grades of CPN and renal tumor occurrence. Hyperplasia of the papilla lining was a component of CPN in both sexes, but there was no pelvic urothelial hyperplasia. High-dose females showed no TBA-related nephrotoxicity. The PWG concluded that both α(2u)-g nephropathy and exacerbated CPN modes of action were operative in TBA renal tumorigenicity in male rats, neither of which has relevance for human cancer risk. Copyright © 2011 Elsevier Inc. All rights reserved.

Early immune response and regulation of IL-2 receptor subunits

NASA Technical Reports Server (NTRS)

Hughes-Fulford, Millie; Sugano, Eiko; Schopper, Thomas; Li, Chai-Fei; Boonyaratanakornkit, J. B.; Cogoli, Augusto

2005-01-01

Affymetrix oligonucleotide arrays were used to monitor expression of 8796 genes and probe sets in activated T-cells; analysis revealed that 217 genes were significantly upregulated within 4 h. Induced genes included transcription factors, cytokines and their receptor genes. Analysis by semi-quantitative RT-PCR confirmed the significant induction of IL-2, IL-2R(gamma) and IL-2R(alpha). Forty-eight of the 217 induced genes are known to or predicted to be regulated by a CRE promoter/enhancer. We found that T-cell activation caused a significant increase in CREB phosphorylation furthermore, inhibition of the PKC pathway by GF109203 reduced CREB activation by 50% and inhibition of the PKA pathway caused a total block of CREB phosphorylation and significantly reduced IFN(gamma), IL-2 and IL-2R(alpha) gene expression by approximately 40% (p<0.001). PKC(theta) plays a major role in T-cell activation: inhibition of PKC significantly reduced the expression of IFN(gamma), IL-2 and IL-2R(alpha). Since PKC blocked activation of CREB, we studied potential cross-talk between the PKC and the PKA/MAPK pathways, PMA-stimulated Jurkat cells were studied with specific signal pathway inhibitors. Extracellular signal-regulated kinase-2 (ERK2) pathway was found to be significantly activated greater than seven-fold within 30 min; however, there was little activation of ERK-1 and no activation of JNK or p38 MAPK. Inhibition of the PKA pathway, but not the PKC pathway, resulted in inhibition of ERK1/2 activation at all time points, inhibition of MEK1 and 2 significantly blocked expression of IL-2 and IL-2R(alpha). Gene expression of IL-2R(alpha) and IFN(gamma) was dependent on PKA in S49 wt cells but not in kin- mutants. Using gel shift analysis, we found that forskolin activation of T-cells resulted in activation of AP1 sites; this increase in nuclear extract AP1 was significantly blocked by MEK1 inhibitor U0126. Taken together, these results suggest that the PKA in addition to PKC and MAPK pathways plays a role in early T-cell activation and induction of IL-2, IL-2R(alpha) and IFN(gamma) gene expression.

Early immune response and regulation of IL-2 receptor subunits.

PubMed

Hughes-Fulford, Millie; Sugano, Eiko; Schopper, Thomas; Li, Chai-Fei; Boonyaratanakornkit, J B; Cogoli, Augusto

2005-09-01

Affymetrix oligonucleotide arrays were used to monitor expression of 8796 genes and probe sets in activated T-cells; analysis revealed that 217 genes were significantly upregulated within 4 h. Induced genes included transcription factors, cytokines and their receptor genes. Analysis by semi-quantitative RT-PCR confirmed the significant induction of IL-2, IL-2R(gamma) and IL-2R(alpha). Forty-eight of the 217 induced genes are known to or predicted to be regulated by a CRE promoter/enhancer. We found that T-cell activation caused a significant increase in CREB phosphorylation furthermore, inhibition of the PKC pathway by GF109203 reduced CREB activation by 50% and inhibition of the PKA pathway caused a total block of CREB phosphorylation and significantly reduced IFN(gamma), IL-2 and IL-2R(alpha) gene expression by approximately 40% (p<0.001). PKC(theta) plays a major role in T-cell activation: inhibition of PKC significantly reduced the expression of IFN(gamma), IL-2 and IL-2R(alpha). Since PKC blocked activation of CREB, we studied potential cross-talk between the PKC and the PKA/MAPK pathways, PMA-stimulated Jurkat cells were studied with specific signal pathway inhibitors. Extracellular signal-regulated kinase-2 (ERK2) pathway was found to be significantly activated greater than seven-fold within 30 min; however, there was little activation of ERK-1 and no activation of JNK or p38 MAPK. Inhibition of the PKA pathway, but not the PKC pathway, resulted in inhibition of ERK1/2 activation at all time points, inhibition of MEK1 and 2 significantly blocked expression of IL-2 and IL-2R(alpha). Gene expression of IL-2R(alpha) and IFN(gamma) was dependent on PKA in S49 wt cells but not in kin- mutants. Using gel shift analysis, we found that forskolin activation of T-cells resulted in activation of AP1 sites; this increase in nuclear extract AP1 was significantly blocked by MEK1 inhibitor U0126. Taken together, these results suggest that the PKA in addition to PKC and MAPK pathways plays a role in early T-cell activation and induction of IL-2, IL-2R(alpha) and IFN(gamma) gene expression.

Characterization of peroxisome proliferator-activiated receptor alpha (PPARalpha)-independent effects of PPARalpha activators in the rodent liver: Di(2-ethylehexyl) phthalate activates the constitutive activated receptor

EPA Science Inventory

Peroxisome proliferator chemicals (PPC) are thought to mediate their effects in rodents on hepatocyte growth and liver cancer through the nuclear receptor peroxisome proliferator-activated receptor alpha (PPARalpha). Recent studies indicate that the plasticizer di-2-ethylhexyl ph...

Vitamin D and renal outcome: the fourth outcome of CKD-MBD? Oshima Award Address 2015.

PubMed

Hamano, Takayuki

2018-04-01

Bone fracture, cardiovascular events, and mortality are three outcomes of chronic kidney disease-mineral and bone disorder (CKD-MBD), and the umbrella concept originally described for dialysis patients. The reported association of serum phosphorus or fibroblast growth factor 23 (FGF23) levels with renal outcome suggests that the fourth relevant outcome of CKD-MBD in predialysis patients is renal outcome. We found that proteinuria of 2+ or greater with a dipstick test was associated with low vitamin D status due to urinary loss of 25-hydroxyvitamin D (25D). Moreover, active vitamin D or its analogues decrease proteinuria. Given our finding that maxacalcitol does not repress renin, the reduction of proteinuria by this agent is likely due to direct upregulation of the nephrin and podocin in podocytes. Moreover, this agent downregulates the mesenchymal marker desmin in podocytes and blocks transforming growth factor-beta autoinduction, leading to attenuation of renal fibrosis in a unilateral ureteral obstructive (UUO) model. These facts are reminiscent of the suppression of epithelial-mesenchymal transition (EMT) by vitamin D. EMT blockage may explain our finding that vitamin D prescription in renal transplant recipients is associated with a lower incidence of cancer. We also reported that low vitamin D status and high FGF23 levels predict a worse renal outcome. However, administration of massive doses of 25D exacerbates renal fibrosis in UUO kidneys in 1alpha-hydroxylase knockout mice. Moreover, FGF23 inhibits 1alpha-hydroxylase in proximal tubules and monocytes. Taken together, local 1,25(OH) 2 D in the kidney tissue but not 25D seems to protect the kidney.

Distinct roles of beta1 metal ion-dependent adhesion site (MIDAS), adjacent to MIDAS (ADMIDAS), and ligand-associated metal-binding site (LIMBS) cation-binding sites in ligand recognition by integrin alpha2beta1.

PubMed

Valdramidou, Dimitra; Humphries, Martin J; Mould, A Paul

2008-11-21

Integrin-ligand interactions are regulated in a complex manner by divalent cations, and previous studies have identified ligand-competent, stimulatory, and inhibitory cation-binding sites. In collagen-binding integrins, such as alpha2beta1, ligand recognition takes place exclusively at the alpha subunit I domain. However, activation of the alphaI domain depends on its interaction with a structurally similar domain in the beta subunit known as the I-like or betaI domain. The top face of the betaI domain contains three cation-binding sites: the metal-ion dependent adhesion site (MIDAS), the ADMIDAS (adjacent to MIDAS), and LIMBS (ligand-associated metal-binding site). The role of these sites in controlling ligand binding to the alphaI domain has yet to be elucidated. Mutation of the MIDAS or LIMBS completely blocked collagen binding to alpha2beta1; in contrast mutation of the ADMIDAS reduced ligand recognition but this effect could be overcome by the activating monoclonal antibody TS2/16. Hence, the MIDAS and LIMBS appear to be essential for the interaction between alphaI and betaI, whereas occupancy of the ADMIDAS has an allosteric effect on the conformation of betaI. An activating mutation in the alpha2 I domain partially restored ligand binding to the MIDAS and LIMBS mutants. Analysis of the effects of Ca(2+), Mg(2+), and Mn(2+) on ligand binding to these mutants showed that the MIDAS is a ligand-competent site through which Mn(2+) stimulates ligand binding, whereas the LIMBS is a stimulatory Ca(2+)-binding site, occupancy of which increases the affinity of Mg(2+) for the MIDAS.

Cytochrome P4502E1 primes macrophages to increase TNF-alpha production in response to lipopolysaccharide.

PubMed

Cao, Qi; Mak, Ki M; Lieber, Charles S

2005-07-01

Kupffer cells become activated in response to elevated levels of LPS during ethanol feeding, but the role of ethanol in the molecular processes of activation remains unclear. Because cytochrome P4502E1 (CYP2E1) is upregulated in Kupffer cells after ethanol, we hypothesized that this effect primes Kupffer cells, sensitizing them to increase TNF-alpha production in response to LPS. However, cultured Kupffer cells rapidly lose their CYP2E1. This difficulty was overcome by transfecting CYP2E1 to RAW 264.7 macrophages. Macrophages with stable increased CYP2E1 expression (E2) displayed increased levels of CD14/Toll-like receptor 4, NADPH oxidase and H2O2, accompanied by activation of ERK1/2, p38, and NF-kappaB. These increases primed E2 cells, sensitizing them to LPS stimuli, with amplification of LPS signaling, resulting in increased TNF-alpha production. Diphenyleneiodonium, a NADPH oxidase inhibitor, and diallyl sulfide, a CYP2E1 inhibitor, decreased approximately equally H2O2 levels in E2 cells, suggesting that NADPH oxidase and CYP2E1 contribute equally to H2O2 generation. Because CYP2E1 expression also enhanced the levels of the membrane localized NADPH oxidase subunits p47phox and p67phox, thereby contributing to the oxidase activation, it may augment H2O2 generation via this mechanism. H2O2, derived in part from NADPH and CYP2E1, activated ERK1/2 and p38. ERK1/2 stimulated TNF-alpha production via activation of NF-kappaB, whereas p38 promoted TNF-alpha production by stabilizing TNF-alpha mRNA. Oxidant generation after CYP2E1 overexpression appears to be central to macrophage priming and their sensitization to LPS. Accordingly, CYP2E1 priming could explain the sensitization of Kupffer cells to LPS activation by ethanol, a critical early step in alcoholic liver disease.

Unlike PPAR{gamma}, PPAR{alpha} or PPAR{beta}/{delta} activation does not promote human monocyte differentiation toward alternative macrophages

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

Bouhlel, Mohamed Amine; Inserm U545, F-59000 Lille; UDSL, F-59000 Lille

2009-08-28

Macrophages adapt their response to micro-environmental signals. While Th1 cytokines promote pro-inflammatory M1 macrophages, Th2 cytokines promote an 'alternative' anti-inflammatory M2 macrophage phenotype. Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors expressed in macrophages where they control the inflammatory response. It has been shown that PPAR{gamma} promotes the differentiation of monocytes into anti-inflammatory M2 macrophages in humans and mice, while a role for PPAR{beta}/{delta} in this process has been reported only in mice and no data are available for PPAR{alpha}. Here, we show that in contrast to PPAR{gamma}, expression of PPAR{alpha} and PPAR{beta}/{delta} overall does not correlate with the expressionmore » of M2 markers in human atherosclerotic lesions, whereas a positive correlation with genes of lipid metabolism exists. Moreover, unlike PPAR{gamma}, PPAR{alpha} or PPAR{beta}/{delta} activation does not influence human monocyte differentiation into M2 macrophages in vitro. Thus, PPAR{alpha} and PPAR{beta}/{delta} do not appear to modulate the alternative differentiation of human macrophages.« less

Processing of MOPC 315 immunoglobulin A oligosaccharides: evidence for endoplasmic reticulum and trans Golgi alpha 1,2-mannosidase activity

PubMed Central

1984-01-01

The processing of asparagine-linked oligosaccharides on the alpha- chains of an immunoglobulin A (IgA) has been investigated using MOPC 315 murine plasmacytoma cells. These cells secrete IgA containing complex-type oligosaccharides that were not sensitive to endo-beta-N- acetylglucosaminidase H. In contrast, oligosaccharides present on the intracellular alpha-chain precursor were of the high mannose-type, remaining sensitive to endo-beta-N-acetylglucosaminidase H despite a long intracellular half-life of 2-3 h. The major [3H]mannose-labeled alpha-chain oligosaccharides identified after a 20-min pulse were Man8GlcNAc2 and Man9GlcNAc2. Following chase incubations, the major oligosaccharide accumulating intracellularly was Man6GlcNAc2, which was shown to contain a single alpha 1,2-linked mannose residue. Conversion of Man6GlcNAc2 to complex-type oligosaccharides occurred at the time of secretion since appreciable amounts of Man5GlcNAc2 or further processed structures could not be detected intracellularly. The subcellular locations of the alpha 1,2-mannosidase activities were studied using carbonyl cyanide m-chlorophenylhydrazone and monensin. Despite inhibiting the secretion of IgA, these inhibitors of protein migration did not effect the initial processing of Man9GlcNAc2 to Man6GlcNAc2. Furthermore, no large accumulation of Man5GlcNAc2 occurred, indicating the presence of two subcellular locations of alpha 1,2-mannosidase activity involved in oligosaccharide processing in MOPC 315 cells. Thus, the first three alpha 1,2-linked mannose residues were removed shortly after the alpha-chain was glycosylated, most likely in rough endoplasmic reticulum, since this processing occurred in the presence of carbonyl cyanide m-chlorophenylhydrazone. However, the removal of the final alpha 1,2-linked mannose residue as well as subsequent carbohydrate processing occurred just before IgA secretion, most likely in the trans Golgi complex since processing of Man6GlcNAc2 to Man5GlcNAc2 was greatly inhibited in the presence of monensin. PMID:6420419

Processing of MOPC 315 immunoglobulin A oligosaccharides: evidence for endoplasmic reticulum and trans Golgi alpha 1,2-mannosidase activity.

PubMed

Hickman, S; Theodorakis, J L; Greco, J M; Brown, P H

1984-02-01

The processing of asparagine-linked oligosaccharides on the alpha-chains of an immunoglobulin A (IgA) has been investigated using MOPC 315 murine plasmacytoma cells. These cells secrete IgA containing complex-type oligosaccharides that were not sensitive to endo-beta-N-acetylglucosaminidase H. In contrast, oligosaccharides present on the intracellular alpha-chain precursor were of the high mannose-type, remaining sensitive to endo-beta-N-acetylglucosaminidase H despite a long intracellular half-life of 2-3 h. The major [3H]mannose-labeled alpha-chain oligosaccharides identified after a 20-min pulse were Man8GlcNAc2 and Man9GlcNAc2. Following chase incubations, the major oligosaccharide accumulating intracellularly was Man6GlcNAc2, which was shown to contain a single alpha 1,2-linked mannose residue. Conversion of Man6GlcNAc2 to complex-type oligosaccharides occurred at the time of secretion since appreciable amounts of Man5GlcNAc2 or further processed structures could not be detected intracellularly. The subcellular locations of the alpha 1,2-mannosidase activities were studied using carbonyl cyanide m-chlorophenylhydrazone and monensin. Despite inhibiting the secretion of IgA, these inhibitors of protein migration did not effect the initial processing of Man9GlcNAc2 to Man6GlcNAc2. Furthermore, no large accumulation of Man5GlcNAc2 occurred, indicating the presence of two subcellular locations of alpha 1,2-mannosidase activity involved in oligosaccharide processing in MOPC 315 cells. Thus, the first three alpha 1,2-linked mannose residues were removed shortly after the alpha-chain was glycosylated, most likely in rough endoplasmic reticulum, since this processing occurred in the presence of carbonyl cyanide m-chlorophenylhydrazone. However, the removal of the final alpha 1,2-linked mannose residue as well as subsequent carbohydrate processing occurred just before IgA secretion, most likely in the trans Golgi complex since processing of Man6GlcNAc2 to Man5GlcNAc2 was greatly inhibited in the presence of monensin.

Environmental triggers of COPD symptoms: a case cross-over study.

PubMed

Sama, Susan R; Kriebel, David; Gore, Rebecca J; DeVries, Rebecca; Rosiello, Richard

2017-01-01

This study investigated the hypothesis that common environmental chemical exposures with known irritant or sensitising properties trigger exacerbations for patients with chronic obstructive pulmonary disease (COPD). We conducted a case cross-over study in 168 patients with COPD who were members of a disease management group in central Massachusetts. Participants completed a baseline health survey and several short exposure surveys. Exposure surveys were administered by a nurse when a participant telephoned to report an exacerbation (case periods) and at a maximum of three randomly identified control periods when they were not experiencing an exacerbation. We compared exposures in the week preceding an exacerbation with exposures in normal (non-exacerbation) weeks. The questionnaire assessed short-term (1 week) home, community and workplace activities and exposures that may be associated with COPD exacerbation. Self-reported exercise was negatively associated with exacerbation (OR=0.59, 95% CI: 0.35 to 1.00). Among the environmental chemical exposures, car and truck exhaust (OR=4.36, 95% CI: 1.76 to 10.80) and use of scented laundry products (OR=2.69, 95% CI: 1.31 to 5.52) showed strong positive effects. Self-reported respiratory infections were strongly associated with exacerbation (OR=7.90, 95% CI 4.29 to 14.50). Variations in outdoor temperature were associated with COPD exacerbation risk (moderate versus cold temperature OR=1.95, 95% CI 1.09 to 3.49 and warm versus cold OR=0.43, 95% CI: 0.26 to 0.70). These results suggest that some environmental chemical exposures may play a role in triggering COPD exacerbations. If confirmed, they may provide useful guidance for patients with COPD to better manage their disease.

Environmental triggers of COPD symptoms: a case cross-over study

PubMed Central

Sama, Susan R; Kriebel, David; Gore, Rebecca J; DeVries, Rebecca; Rosiello, Richard

2017-01-01

Introduction This study investigated the hypothesis that common environmental chemical exposures with known irritant or sensitising properties trigger exacerbations for patients with chronic obstructive pulmonary disease (COPD). Methods We conducted a case cross-over study in 168 patients with COPD who were members of a disease management group in central Massachusetts. Participants completed a baseline health survey and several short exposure surveys. Exposure surveys were administered by a nurse when a participant telephoned to report an exacerbation (case periods) and at a maximum of three randomly identified control periods when they were not experiencing an exacerbation. We compared exposures in the week preceding an exacerbation with exposures in normal (non-exacerbation) weeks. The questionnaire assessed short-term (1 week) home, community and workplace activities and exposures that may be associated with COPD exacerbation. Results Self-reported exercise was negatively associated with exacerbation (OR=0.59, 95% CI: 0.35 to 1.00). Among the environmental chemical exposures, car and truck exhaust (OR=4.36, 95% CI: 1.76 to 10.80) and use of scented laundry products (OR=2.69, 95% CI: 1.31 to 5.52) showed strong positive effects. Self-reported respiratory infections were strongly associated with exacerbation (OR=7.90, 95% CI 4.29 to 14.50). Variations in outdoor temperature were associated with COPD exacerbation risk (moderate versus cold temperature OR=1.95, 95% CI 1.09 to 3.49 and warm versus cold OR=0.43, 95% CI: 0.26 to 0.70). Conclusions These results suggest that some environmental chemical exposures may play a role in triggering COPD exacerbations. If confirmed, they may provide useful guidance for patients with COPD to better manage their disease. PMID:29071071

Decreased enzyme activity and contents of hepatic branched-chain alpha-keto acid dehydrogenase complex subunits in a rat model for type 2 diabetes mellitus.

PubMed

Bajotto, Gustavo; Murakami, Taro; Nagasaki, Masaru; Sato, Yuzo; Shimomura, Yoshiharu

2009-10-01

The mitochondrial branched-chain alpha-keto acid dehydrogenase complex (BCKDC) is responsible for the committed step in branched-chain amino acid catabolism. In the present study, we examined BCKDC regulation in Otsuka Long-Evans Tokushima Fatty (OLETF) rats both before (8 weeks of age) and after (25 weeks of age) the onset of type 2 diabetes mellitus. Long-Evans Tokushima Otsuka (LETO) rats were used as controls. Plasma branched-chain amino acid and branched-chain alpha-keto acid concentrations were significantly increased in young and middle-aged OLETF rats. Although the hepatic complex was nearly 100% active in all animals, total BCKDC activity and protein abundance of E1alpha, E1beta, and E2 subunits were markedly lower in OLETF than in LETO rats at 8 and 25 weeks of age. In addition, hepatic BCKDC activity and protein amounts were significantly decreased in LETO rats aged 25 weeks than in LETO rats aged 8 weeks. In skeletal muscle, E1beta and E2 proteins were significantly reduced, whereas E1alpha tended to increase in OLETF rats. Taken together, these results suggest that (1) whole-body branched-chain alpha-keto acid oxidation capacity is extremely reduced in OLETF rats independently of diabetes development, (2) the aging process decreases BCKDC activity and protein abundance in the liver of normal rats, and (3) differential posttranscriptional regulation for the subunits of BCKDC may exist in skeletal muscle.

High glucose induces inflammatory cytokine through protein kinase C-induced toll-like receptor 2 pathway in gingival fibroblasts

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

Jiang, Shao-Yun, E-mail: jiangshaoyun@yahoo.com; Wei, Cong-Cong; Shang, Ting-Ting

2012-10-26

Highlights: Black-Right-Pointing-Pointer High glucose significantly induced TLR2 expression in gingival fibroblasts. Black-Right-Pointing-Pointer High glucose increased NF-{kappa}B p65 nuclear activity, IL-1{beta} and TNF-{alpha} levels. Black-Right-Pointing-Pointer PKC-{alpha}/{delta}-TLR2 pathway is involved in periodontal inflammation under high glucose. -- Abstract: Toll-like receptors (TLRs) play a key role in innate immune response and inflammation, especially in periodontitis. Meanwhile, hyperglycemia can induce inflammation in diabetes complications. However, the activity of TLRs in periodontitis complicated with hyperglycemia is still unclear. In the present study, high glucose (25 mmol/l) significantly induced TLR2 expression in gingival fibroblasts (p < 0.05). Also, high glucose increased nuclear factor kappa B (NF-{kappa}B)more » p65 nuclear activity, tumor necrosis factor-{alpha} (TNF-{alpha}) and interleukin-l{beta} (IL-1{beta}) levels. Protein kinase C (PKC)-{alpha} and {delta} knockdown with siRNA significantly decreased TLR2 and NF-{kappa}B p65 expression (p < 0.05), whereas inhibition of PKC-{beta} had no effect on TLR2 and NF-{kappa}B p65 under high glucose (p < 0.05). Additional studies revealed that TLR2 knockdown significantly abrogated high-glucose-induced NF-{kappa}B expression and inflammatory cytokine secretion. Collectively, these data suggest that high glucose stimulates TNF-{alpha} and IL-1{beta} secretion via inducing TLR2 through PKC-{alpha} and PKC-{delta} in human gingival fibroblasts.« less

Doxycycline improves clinical outcomes during cystic fibrosis exacerbations.

PubMed

Xu, Xin; Abdalla, Tarek; Bratcher, Preston E; Jackson, Patricia L; Sabbatini, Gina; Wells, J Michael; Lou, Xiang-Yang; Quinn, Rebecca; Blalock, J Edwin; Clancy, J P; Gaggar, Amit

2017-04-01

Matrix metalloprotease-9 (MMP-9) plays a role in progression of cystic fibrosis, and doxycycline can reduce MMP-9 in vitro Here, we explore the effect of doxycycline during cystic fibrosis exacerbation treatment on MMP-9 related readouts and clinical end-points.This randomised, double-blind, placebo-controlled study enrolled hospitalised patients with cystic fibrosis undergoing exacerbation. In total, 20 participants were given doxycycline and 19 participants were given placebo over an 8-day period during hospitalisation. Biospecimens were collected at the beginning and the end of the study period. Primary end-points were total MMP-9 levels in the sputum and safety/tolerability. Secondary end-points included change in lung function, time to next exacerbation, and markers of MMP-9-related protease activity (active MMP-9 and TIMP-1). Nonparametric testing was used for within-group and between-group analyses.Doxycycline was well tolerated, with no treatment discontinuations or serious adverse events. Doxycycline reduced total sputum MMP-9 levels by 63.2% (p<0.05), and was also associated with a 56.5% reduction in active MMP-9 levels (p<0.05), a 1.6-fold increase in sputum TIMP-1 (p<0.05), improvement in forced expiratory volume in 1 s (p<0.05), and an increase in time to next exacerbation (p<0.01).Adjunctive use of doxycycline improved dysregulated MMP-9 levels in sputum, along with biomarkers consistent with a reduced proteolytic pulmonary environment. Improvement in clinical outcome measures suggests an important therapeutic benefit of doxycycline for individuals with cystic fibrosis. Copyright ©ERS 2017.

Expression of alpha-AR subtypes in T lymphocytes and role of the alpha-ARs in mediating modulation of T cell function.

PubMed

Bao, Jing-Yin; Huang, Yan; Wang, Feng; Peng, Yu-Ping; Qiu, Yi-Hua

2007-01-01

Previous work in our laboratory has shown that alpha-adrenoreceptors (alpha-ARs) and beta-ARs exist on lymphocytes from functional profile, and that the receptors mediate the regulation of lymphocyte function by catecholamines. In the present study, we directly examined the expression of alpha-AR subtypes, alpha(1)-AR and alpha(2)-AR mRNAs, in T lymphocytes and explored the roles of the alpha-AR subtypes and intracellular signal transduction mechanisms linked to the receptors in mediating the modulation of T lymphocyte function. T lymphocytes from mesenteric lymph nodes of rats were purified by using a nylon wool column. Reverse transcription polymerase chain reaction was used to detect the expression of alpha(1)-AR and alpha(2)-AR mRNAs in the freshly isolated T cells and the mitogen concanavalin A (Con A)-activated lymphocytes. Colorimetric methylthiazoletetrazolium assay was employed to measure lymphocyte proliferation induced by Con A. Interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) levels in the Con A-stimulated lymphocyte culture supernatants were examined by enzyme-linked immunosorbent assay. T cells expressed both alpha(1)-AR and alpha(2)-AR mRNAs. The expression of both alpha(1)-AR and alpha(2)-AR mRNAs was significantly higher in the Con A-activated lymphocytes than in the resting lymphocytes. Phenylephrine, a selective alpha(1)-AR agonist, had no evident effect on lymphocyte proliferation nor on IFN-gamma and IL-4 production induced by Con A. However, the selective alpha(2)-AR agonist clonidine attenuated Con A-induced lymphocyte proliferation as well as IFN-gamma and IL-4 production. The inhibited lymphocyte proliferation and IFN-gamma and IL-4 production by clonidine were blocked by yohimbine, an alpha(2)-AR antagonist. Either phospholipase C inhibitor U-73122 or protein kinase C inhibitor chelerythrine partially prevented the suppressive effect of clonidine on Con A-stimulated lymphocyte proliferation and IL-4 production. T lymphocytes express both alpha(1)-ARs and alpha(2)-ARs, but only the alpha(2)-ARs participate in the suppressive modulation of lymphocyte proliferation and cytokine production in vitro. The inhibitory effect of alpha(2)-AR stimulation on lymphocyte function is partially mediated via the phospholipase C-protein kinase C pathway. (c) 2008 S. Karger AG, Basel.

The electrophoretically 'slow' and 'fast' forms of the alpha 2-macroglobulin molecule.

PubMed Central

Barrett, A J; Brown, M A; Sayers, C A

1979-01-01

alpha 2-Macroglobulin (alpha 2M) was isolated from human plasma by a four-step procedure: poly(ethylene glyco) fractionation, gel chromatography, euglobulin precipitation and immunoadsorption. No contaminants were detected in the final preparations by electrophoresis or immunoprecipitation. The protein ran as a single slow band in gel electrophoresis, and was designated 'S-alpha 2M'. S-alpha 2M bound about 2 mol of trypsin/mol. Treatment of S-alpha 2M with a proteinase or ammonium salts produced a form of the molecule more mobile in electrophoresis, and lacking proteinase-binding activity (F-alpha 2M). The electrophoretic mobility of the F-alpha 2M resulting from reaction with NH4+ salts was identical with that of proteinase complexes. We attribute the change in electrophoretic mobility of the alpha 2M to a conformation change, but there was no evidence of a change in pI or Strokes radius. Electrophoresis of S-alpha 2M in the presence of sodium dodecylsulphate gave results consistent with the view that the alpha 2M molecule is a tetramer of identical subunits, assembled as a non-covalent pair of disulphide-linked dimers. Some of the subunits seemed to be 'nicked' into two-thires-length and one-third-length chains, however. This was not apparent with F-alpha 2M produced by ammonium salts. F-alpha 2M produced by trypsin showed two new bands attributable to cleavage of the subunit polypeptide chain near the middle. Immunoassays of F-alpha 2M gave 'rockets' 12-29% lower than those with S-alpha 2M. The nature of the interactions between subunits in S-alpha 2M and F-alpha 2M was investigated by treating each form with glutaraldehyde before electrophoresis in the presence of sodium dodecyl sulphate. A much greater degree of cross-linking was observed with the F-alpha 2M, indicating that the subunits interact most closely in this form of the molecule. Exposure of S-alpha 2M to 3 M-urea or pH3 resulted in dissociation to the disulphide-bonded half-molecules; these did not show the proteinase-binding activity characteristic of the intact alpha 2M. F-alpha 2M was less easily dissociated than was S-alpha 2M. S-alpha 2M was readily dissociated to the quarter-subunits by mild reduction, with the formation of 3-4 new thiol groups per subunit. Inact reactive alpha 2M could then be regenerated in high yield by reoxidation of the subunits. F-alpha 2M formed by reaction with a proteinase or ammonium salts was not dissociated under the same conditions, although the interchain disulphide bonds were reduced. If the thiol groups of the quarter-subunits of S-alpha 2M were blocked by carboxymethylation, oxidative reassociation did not occur. Nevertheless treatment of these subunits with methylammonium salts or a proteinase caused the reassembly of half-molecules and intact (F-) tetramers. It is emphasized that F-alpha 2M does not have the properties of a denatured form of the protein... Images Fig. 3. Fig. 4. Fig. 5. Fig. 6. PMID:91367

The PPARdelta agonist GW501516 suppresses interleukin-6-mediated hepatocyte acute phase reaction via STAT3 inhibition.

PubMed

Kino, T; Rice, K C; Chrousos, G P

2007-05-01

Interleukin-6 and downstream liver effectors acute phase reactants are implicated in the systemic inflammatory reaction. Peroxisome proliferator-activated receptor delta (PPARdelta), which binds to and is activated by a variety of fatty acids, was recently shown to have anti-inflammatory actions. We examined the ability of the synthetic PPARdelta agonist GW501516 to suppress interleukin-6-induced expression of acute phase proteins in human hepatoma HepG2 cells and rat primary hepatocytes. Results GW501516 dose-dependently suppressed interleukin-6-induced mRNA expression of the acute phase protein alpha1-antichymotrypsin in HepG2 cells. The compound also suppressed interleukin-6-induced mRNA expression of alpha2-acid glycoprotein, beta-fibrinogen and alpha2-macroglobulin in and the secretion of C-reactive protein by rat primary hepatocytes. Depletion of the PPARdelta receptor, but not of PPARalpha or gamma, attenuated the suppressive effect of GW501516 on interleukin-6-induced alpha1-antichymotrypsin mRNA expression, indicating that PPARdelta specifically mediated this effect. Since interleukin-6 stimulates the transcriptional activity of the alpha1-antichymotrypsin promoter by activating the signal transducer and activator of transcription (STAT) 3, we examined functional interaction of this transcription factor and PPARdelta on this promoter. Overexpression of PPARdelta enhanced the suppressive effect of GW501516 on STAT3-activated transcriptional activity of the alpha1-antichymotrypsin promoter, while GW501516 suppressed interleukin-6-induced binding of this transcription factor to this promoter. These findings indicate that agonist-activated PPARdelta interferes with interleukin-6-induced acute phase reaction in the liver by inhibiting the transcriptional activity of STAT3. PPARdelta agonists might be useful for the suppression of systemic inflammatory reactions in which IL-6 plays a central role.

Cytotoxic triterpenoid saponins from the fruits of Aesculus pavia L.

PubMed

Zhang, Zhizhen; Li, Shiyou

2007-08-01

Continued chemical investigation on the fruits of North American Aesculus pavia L. resulted in the isolation and identification of 13 polyhydroxyoleanene pentacyclic triterpenoid saponins, named aesculiosides IIe-IIk (1-7), and IIIa-IIIf (8-13), together with 18 known compounds: aesculiosides Ia-Ie (14-18), IIa-IId (19-22), IVa-IVc (23-25), 3-O-[beta-D-galactopyranosyl(1-->2)]-alpha-L-arabinofuranosyl(1-->3)-beta-D-glucuronopyranosyl-21,22-O-diangeloyl-3beta,15 alpha,16 alpha,21 beta,22 alpha,28-hexahydroxyolean-12-ene (26), 3-O-[beta-D-glucopyranosyl(1-->2)]-alpha-L-arabinofuranosyl(1-->3)-beta-D-glucuronopyranosyl-21,22-O-diangeloyl-3beta,16 alpha,21 beta,22 alpha,24 beta,28-hexahydroxyolean-12-ene (27), 3-O-[beta-D-galactopyranosyl(1-->2)]-alpha-L-arabinofuranosyl(1-->3)-beta-D-glucuronopyranosyl-21,22-O-diangeloyl-3beta,16 alpha,21 beta,22 alpha,28-pentahydroxyolean-12-ene (28), R(1)-barrigenol (29), scopolin (30), and 5-methoxyscopolin (31). The structures of these compounds were elucidated by spectroscopic and chemical analyses. Compounds 14-22 and 26-28 were tested in vitro for their activity against 59 cell lines from nine different human cancers including leukemia, non-small cell lung, colon, CNS, melanoma, ovarian, renal, prostate, and breast. It was found that compounds with two-acyl groups at C-21 and C-22 had cytotoxic activity for all cell lines tested with GI(50) 0.175-8.71 microM, while compounds without acyl groups at C-21 and C-22 had weak or no cytotoxic activity. These results suggest that the acyl groups at C-21 and C-22 are essential for their activity.

Differential activation of G-proteins by mu-opioid receptor agonists.

PubMed

Saidak, Zuzana; Blake-Palmer, Katherine; Hay, Debbie L; Northup, John K; Glass, Michelle

2006-03-01

We investigated the ability of the activated mu-opioid receptor (MOR) to differentiate between myristoylated G(alphai1) and G(alphaoA) type G(alpha) proteins, and the maximal activity of a range of synthetic and endogenous agonists to activate each G(alpha) protein. Membranes from HEK293 cells stably expressing transfected MOR were chaotrope extracted to denature endogenous G-proteins and reconstituted with specific purified G-proteins. The G(alpha) subunits were generated in bacteria and were demonstrated to be recognised equivalently to bovine brain purified G(alpha) protein by CB(1) cannabinoid receptors. The ability of agonists to catalyse the MOR-dependent GDP/[(35)S]GTP(gamma)S exchange was then compared for G(alphai1) and G(alphaoA). Activation of MOR by DAMGO produced a high-affinity saturable interaction for G(alphaoA) (K(m)=20+/-1 nM) but a low-affinity interaction with G(alphai1) (K(m)=116+/-12 nM). DAMGO, met-enkephalin and leucine-enkephalin displayed maximal G(alpha) activation among the agonists evaluated. Endomorphins 1 and 2, methadone and beta-endorphin activated both G(alpha) to more than 75% of the maximal response, whereas fentanyl partially activated both G-proteins. Buprenorphine and morphine demonstrated a statistically significant difference between the maximal activities between G(alphai1) and G(alphaoA). Interestingly, DAMGO, morphine, endomorphins 1 and 2, displayed significant differences in the potencies for the activation of the two G(alpha). Differences in maximal activity and potency, for G(alphai1) versus G(alphaoA), are both indicative of agonist selective activation of G-proteins in response to MOR activation. These findings may provide a starting point for the design of drugs that demonstrate greater selectivity between these two G-proteins and therefore produce a more limited range of effects.

Characterization of large area ZnS(Ag) detector for gross alpha and beta activity measurements in tap water plants

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

Lunardon, M.; Cester, D.; Mistura, G.

2015-07-01

In this work we present the characterization of a large area 200 x 200 mm{sup 2} EJ-444 scintillation detector to be used for monitoring gross alpha and beta activity in tap water plants. Specific tests were performed to determine the best setup to readout the light from the detector side in order to have the possibility to stack many detectors and get a compact device with total active area of the order of 1 m{sup 2}. Alpha/Beta discrimination, efficiency and homogeneity tests were carried out with alpha and beta sources. Background from ambient radioactivity was measured as well. Alpha/beta real-timemore » monitoring in drinking water is a goal of the EU project TAWARA{sub R}TM. (authors)« less

Modulation of intracellular Ca(2+) via alpha(1B)-adrenoreceptor signaling molecules, G alpha(h) (transglutaminase II) and phospholipase C-delta 1.

PubMed

Kang, Sung Koo; Kim, Dae Kyong; Damron, Derek S; Baek, Kwang Jin; Im, Mie-Jae

2002-04-26

We characterized the alpha(1B)-adrenoreceptor (alpha(1B)-AR)-mediated intracellular Ca(2+) signaling involving G alpha(h) (transglutaminase II, TGII) and phospholipase C (PLC)-delta 1 using DDT1-MF2 cell. Expression of wild-type TGII and a TGII mutant lacking transglutaminase activity resulted in significant increases in a rapid peak and a sustained level of intracellular Ca(2+) concentration ([Ca(2+)](i)) in response to activation of the alpha(1B)-AR. Expression of a TGII mutant lacking the interaction with the receptor or PLC-delta 1 substantially reduced both the peak and sustained levels of [Ca(2+)](i). Expression of TGII mutants lacking the interaction with PLC-delta 1 resulted in a reduced capacitative Ca(2+) entry. Reduced expression of PLC-delta 1 displayed a transient elevation of [Ca(2+)](i) and a reduction in capacitative Ca(2+) entry. Expression of the C2-domain of PLC-delta 1, which contains the TGII interaction site, resulted in reduction of the alpha(1B)-AR-evoked peak increase in [Ca(2+)](i), while the sustained elevation in [Ca(2+)](i) and capacitative Ca(2+) entry remained unchanged. These findings demonstrate that stimulation of PLC-delta 1 via coupling of the alpha(1B)-AR with TGII evokes both Ca(2+) release and capacitative Ca(2+) entry and that capacitative Ca(2+) entry is mediated by the interaction of TGII with PLC-delta 1.

Gonadotropin-releasing hormone (GnRH) agonist triptorelin inhibits estradiol-induced serum response element (SRE) activation and c-fos expression in human endometrial, ovarian and breast cancer cells.

PubMed

Gründker, Carsten; Günthert, Andreas R; Hellriegel, Martin; Emons, Günter

2004-11-01

The majority of human endometrial (>80%), ovarian (>80%) and breast (>50%) cancers express GnRH receptors. Their spontaneous and epidermal growth-factor-induced proliferation is dose- and time-dependently reduced by treatment with GnRH and its agonists. In this study, we demonstrate that the GnRH agonist triptorelin inhibits estradiol (E2)-induced cancer cell proliferation. The proliferation of quiescent estrogen receptor alpha (ER alpha)-/ER beta-positive, but not of ER alpha-negative/ER beta-positive endometrial, ovarian and breast cancer cell lines, was significantly stimulated (P<0.001) (ANOVA) after treatment with E2 (10(-8) M). This effect was time- and dose-dependently antagonized by simultaneous treatment with triptorelin. The inhibitory effect was maximal at 10(-5) M concentration of triptorelin (P<0.001). In addition, we could show that, in ER alpha-/ER beta-positive cell lines, E2 induces activation of serum response element (SRE) and expression of the immediate early-response gene c-fos. These effects were blocked by triptorelin (P<0.001). E2-induced activation of estrogen-response element (ERE) was not affected by triptorelin. The transcriptional activation of SRE by E2 is due to ER alpha activation of the mitogen-activated protein kinase (MAPK) pathway. This pathway is impeded by GnRH, resulting in a reduction of E2-induced SRE activation and, in consequence, a reduction of E2-induced c-fos expression. This causes downregulation of E2-induced cancer cell proliferation.

Differential interaction of the tyrosine phosphatases PTP-SL, STEP and HePTP with the mitogen-activated protein kinases ERK1/2 and p38alpha is determined by a kinase specificity sequence and influenced by reducing agents.

PubMed Central

Muñoz, Juan José; Tárrega, Céline; Blanco-Aparicio, Carmen; Pulido, Rafael

2003-01-01

The protein tyrosine phosphatases (PTPs) PTP-SL, STEP and HePTP are mitogen-activated protein kinase (MAPK) substrates and regulators that bind to MAPKs through a kinase-interaction motif (KIM) located in their non-catalytic regulatory domains. We have found that the binding of these PTPs to the MAPKs extracellular-signal-regulated kinase 1 and 2 (ERK1/2), and p38alpha is differentially determined by the KIM-adjacent C-terminal regions of the PTPs, which have been termed kinase-specificity sequences, and is influenced by reducing agents. Under control conditions, PTP-SL bound preferentially to ERK1/2, whereas STEP and HePTP bound preferentially to p38alpha. Under reducing conditions, the association of p38alpha with STEP or HePTP was impaired, whereas the association with PTP-SL was unaffected. On the other hand, the association of ERK1/2 with HePTP was increased under reducing conditions, whereas the association with STEP or PTP-SL was unaffected. In intact cells, PTP-SL and STEP distinctively regulated the kinase activity and the nuclear translocation of ERK1/2 and p38alpha. Our results suggest that intracellular redox conditions could modulate the activity and subcellular location of ERK1/2 and p38alpha by controlling their association with their regulatory PTPs. PMID:12583813

Growth-related gene product {alpha}: A chemotactic cytokine for neutrophils in rheumatoid arthritis

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

Koch, A.E.; Pope, R.M.; Shah, M.R.

Leukocyte recruitment is critical in the inflammation seen in rheumatoid arthritis (RA). To determine whether the chemokine growth-related gene product {alpha} (gro{alpha}) plays a role in this process, we examined synovial tissue (ST), synovial fluid (SF), and plasma samples from 102 patients with arthritis. RA SF contained more antigenic gro{alpha} (mean 5.3 {+-} 1.9 ng/ml) than did SFs from either osteoarthritis (OA) or other forms of arthritis (mean 0.1 ng/ml) (p < 0.05). RA plasma contained more gro{alpha} (mean 4.3 {+-} 1.8 ng/ml) than normal plasma (mean 0.1 ng/ml) (p < 0.05). RA ST fibroblasts (1.2 x 10{sup 5}/cells/ml RPMImore » 1640/24 h) produced antigenic gro{alpha} (mean 0.2 {+-} 0.1 ng/ml), and this production was increased significantly upon incubation with TNF-{alpha} (mean 1.3 {+-} 0.3 ng/ml) or IL-1{beta} (mean 2.3 {+-} 0.6 ng/ml) (p < 0.05). Cells from RA SF also produced gro{alpha}: neutrophils (PMNs) (10{sup 7} cells/ml/24 h) produced 3.7 {+-} 0.7 ng/ml. RA SF mononuclear cells produced gro{alpha}, particularly upon incubation with LPS or PHA. Immunoreactive ST gro{alpha} was found in greater numbers of RA compared with either OA or normal lining cells, as well as in RA compared with OA subsynovial macrophages (p < 0.05). IL-8 accounted for a mean of 36% of the RA SF chemotactic activity for PMNs, while epithelial neutrophil-activating peptide-78 accounted for 34%, and gro{alpha} for 28%, of this activity. Combined neutralization of all three chemokines in RA SFs resulted in a mean decrease of 50% of the chemotactic activity for PMNs present in the RA SFs. These results indicate that gro{alpha} plays an important role in the ingress of PMNs into the RA joint. 54 refs., 6 figs., 1 tab.« less

Transformation of arachidonate into 6-oxoprostaglandin F1 alpha, thromboxane B2 and prostaglandin E2 by sheep lung microsomal fraction.

PubMed Central

Tai, H H; Yuan, B; Wu, A T

1978-01-01

In the presence of haemoglobin and isoproterenol, the microsomal fraction of sheep lung catalysed the conversion of arachidonate predominantly into thromboxane B2 and to a lesser extent into 6-oxoprostaglandin F1alpha. Very little prostaglandin E2 and prostaglandin F2alpha were formed. If reduced glutathione was added in combination with haemoglobin and isoproterenol, the synthesis of prostaglandin E2 was favoured over that of thromboxane B2 and 6-oxoprostaglandin F1alpha. The identities of these products were confirmed by t.l.c. and by combined g.l.c.-mass spectrometry. These results indicate that microsomal fraction of sheep lung possesses active prostaglandin synthase, prostacyclin synthase and thromboxane synthase activities. PMID:637853

Characterization of the human pH- and PKA-activated ClC-2G(2 alpha) Cl- channel.

PubMed

Sherry, A M; Stroffekova, K; Knapp, L M; Kupert, E Y; Cuppoletti, J; Malinowska, D H

1997-08-01

A ClC-2G(2 alpha) Cl- channel was identified to be present in human lung and stomach, and a partial cDNA for this Cl- channel was cloned from a human fetal lung library. A full-length expressible human ClC-2G(2 alpha) cDNA was constructed by ligation of mutagenized expressible rabbit ClC-2G(2 alpha) cDNA with the human lung ClC-2G(2 alpha) cDNA, expressed in oocytes, and characterized at the single-channel level. Adenosine 3',5'-cyclic monophosphate-dependent protein kinase (PKA) treatment increased the probability of opening of the channel (Po). After PKA activation, the channel exhibited a linear (r = 0.99) current-voltage curve with a slope conductance of 22.1 +/- 0.8 pS in symmetric 800 mM tetraethylammonium chloride (TEACl; pH 7.4). Under fivefold gradient conditions of TEACl, a reversal potential of +21.5 +/- 2.8 mV was measured demonstrating anion-to-cation discrimination. As previously demonstrated for the rabbit ClC-2G(2 alpha) Cl- channel, the human analog, hClC-2G(2 alpha), was active at pH 7.4 as well as when the pH of the extracellular face of the channel (trans side of the bilayer; pHtrans) was asymmetrically reduced to pH 3.0. The extent of PKA activation was dependent on pHtrans. With PKA treatment, Po increased fourfold with a pHtrans of 7.4 and eightfold with a pHtrans of 3.0. Effects of sequential PKA addition followed by pHtrans reduction on the same channel suggested that the PKA- and pH-dependent increases in channel Po were separable and cumulative. Northern analysis showed ClC-2G(2 alpha) mRNA to be present in human adult and fetal lung and adult stomach, and quantitative reverse transcriptase-polymerase chain reaction showed this channel to be present in the adult human lung and stomach at about one-half the level found in fetal lung. The findings of the present study suggest that the ClC-2G(2 alpha) Cl- channel may play an important role in Cl- transport in the fetal and adult human lung.

Mycophenolic acid induces ATP-binding cassette transporter A1 (ABCA1) expression through the PPAR{gamma}-LXR{alpha}-ABCA1 pathway

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

Xu, Yanni; Lai, Fangfang; Xu, Yang

2011-11-04

Highlights: Black-Right-Pointing-Pointer Using an ABCA1p-LUC HepG2 cell line, we found that MPA upregulated ABCA1 expression. Black-Right-Pointing-Pointer MPA induced ABCA1 and LXR{alpha} protein expression in HepG2 cells. Black-Right-Pointing-Pointer PPAR{gamma} antagonist GW9662 markedly inhibited MPA-induced ABCA1 and LXR{alpha} protein expression. Black-Right-Pointing-Pointer The effect of MPA upregulating ABCA1 was due mainly to activation of the PPAR{gamma}-LXR{alpha}-ABCA1 pathway. -- Abstract: ATP-binding cassette transporter A1 (ABCA1) promotes cholesterol and phospholipid efflux from cells to lipid-poor apolipoprotein A-I and plays an important role in atherosclerosis. In a previous study, we developed a high-throughput screening method using an ABCA1p-LUC HepG2 cell line to find upregulators of ABCA1.more » Using this method in the present study, we found that mycophenolic acid (MPA) upregulated ABCA1 expression (EC50 = 0.09 {mu}M). MPA upregulation of ABCA1 expression was confirmed by real-time quantitative reverse transcription-PCR and Western blot analysis in HepG2 cells. Previous work has indicated that MPA is a potent agonist of peroxisome proliferator-activated receptor gamma (PPAR{gamma}; EC50 = 5.2-9.3 {mu}M). Liver X receptor {alpha} (LXR{alpha}) is a target gene of PPAR{gamma} and may directly regulate ABCA1 expression. Western blot analysis showed that MPA induced LXR{alpha} protein expression in HepG2 cells. Addition of PPAR{gamma} antagonist GW9662 markedly inhibited MPA-induced ABCA1 and LXR{alpha} protein expression. These data suggest that MPA increased ABCA1 expression mainly through activation of PPAR{gamma}. Thus, the effects of MPA on upregulation of ABCA1 expression were due mainly to activation of the PPAR{gamma}-LXR{alpha}-ABCA1 signaling pathway. This is the first report that the antiatherosclerosis activity of MPA is due to this mechanism.« less

The PPAR alpha agonist gemfibrozil is an ineffective treatment for spinal cord injured mice

PubMed Central

Almad, Akshata; Lash, A. Todd; Wei, Ping; Lovett-Racke, Amy E.; McTigue, Dana M.

2017-01-01

Peroxisome Proliferator Activated Receptor (PPAR)-α is a key regulator of lipid metabolism and recent studies reveal it also regulates inflammation in several different disease models. Gemfibrozil, an agonist of PPAR-α, is a FDA approved drug for hyperlipidemia and has been shown to inhibit clinical signs in a rodent model of multiple sclerosis. Since many studies have shown improved outcome from spinal cord injury (SCI) by anti-inflammatory and neuroprotective agents, we tested the efficacy of oral gemfibrozil given before or after SCI for promoting tissue preservation and behavioral recovery after spinal contusion injury in mice. Unfortunately, the results were contrary to our hypothesis; in our first attempt, gemfibrozil treatment exacerbated locomotor deficits and increased tissue pathology after SCI. In subsequent experiments, the behavioral effects were not replicated but histological outcomes again were worse. We also tested the efficacy of a different PPAR-α agonist, fenofibrate, which also modulates immune responses and is beneficial in several neurodegenerative disease models. Fenofibrate treatment did not improve recovery, although there was a slight trend for a modest increase in histological tissue sparing. Based on our results, we conclude that PPAR-α agonists yield either no effect or worsen recovery from spinal cord injury, at least at the doses and the time points of drug delivery tested here. Further, patients sustaining spinal cord injury while taking gemfibrozil might be prone to exacerbated tissue damage. PMID:21963672

Roles of Ca(v) channels and AHNAK1 in T cells: the beauty and the beast.

PubMed

Matza, Didi; Flavell, Richard A

2009-09-01

T lymphocytes require Ca2+ entry though the plasma membrane for their activation and function. Recently, several routes for Ca2+ entry through the T-cell plasma membrane after activation have been described. These include calcium release-activated channels (CRAC), transient receptor potential (TRP) channels, and inositol-1,4,5-trisphosphate receptors (IP3Rs). Herein we review the emergence of a fourth new route for Ca2+ entry, composed of Ca(v) channels (also known as L-type voltage-gated calcium channels) and the scaffold protein AHNAK1 (AHNAK/desmoyokin). Both helper (CD4+) and killer (CD8+) T cells express high levels of Ca(v)1 alpha1 subunits (alpha1S, alpha1C, alpha1D, and alpha1F) and AHNAK1 after their differentiation and require these molecules for Ca2+ entry during an immune response. In this article, we describe the observations and open questions that ultimately suggest the involvement of multiple consecutive routes for Ca2+ entry into lymphocytes, one of which may be mediated by Ca(v) channels and AHNAK1.

Demonstration of 3 alpha(17 beta)-hydroxysteroid dehydrogenase distinct from 3 alpha-hydroxysteroid dehydrogenase in hamster liver.

PubMed Central

Ohmura, M; Hara, A; Nakagawa, M; Sawada, H

1990-01-01

NAD(+)-linked and NADP(+)-linked 3 alpha-hydroxysteroid dehydrogenases were purified to homogeneity from hamster liver cytosol. The two monomeric enzymes, although having similar molecular masses of 38,000, differed from each other in pI values, activation energy and heat stability. The two proteins also gave different fragmentation patterns by gel electrophoresis after digestion with protease. The NADP(+)-linked enzyme catalysed the oxidoreduction of various 3 alpha-hydroxysteroids, whereas the NAD(+)-linked enzyme oxidized the 3 alpha-hydroxy group of pregnanes and some bile acids, and the 17 beta-hydroxy group of testosterone and androstanes. The thermal stabilities of the 3 alpha- and 17 beta-hydroxysteroid dehydrogenase activities of the NAD(+)-linked enzyme were identical, and the two enzyme activities were inhibited by mixing 17 beta- and 3 alpha-hydroxysteroid substrates, respectively. Medroxyprogesterone acetate, hexoestrol and 3 beta-hydroxysteroids competitively inhibited 3 alpha- and 17 beta-hydroxysteroid dehydrogenase activities of the enzyme. These results show that hamster liver contains a 3 alpha(17 beta)-hydroxysteroid dehydrogenase structurally and functionally distinct from 3 alpha-hydroxysteroid dehydrogenase. Images Fig. 1. Fig. 2. PMID:2317205

Relative changes in the abundance of branchial Na(+)/K(+)-ATPase alpha-isoform-like proteins in marine euryhaline milkfish (Chanos chanos) acclimated to environments of different salinities.

PubMed

Tang, Cheng-Hao; Chiu, Yu-Huei; Tsai, Shu-Chuan; Lee, Tsung-Han

2009-08-01

Previous studies revealed that upon salinity challenge, milkfish (Chanos chanos), the euryhaline teleost, exhibited adaptive changes in branchial Na(+)/K(+)-ATPase (NKA) activity with different Na(+) and K(+) affinities. Since alteration of activity and ion-affinity may be influenced by changes in different isoforms of NKA alpha-subunit (i.e., the catalytic subunit), it is, thus, intriguing to compare the patterns of protein abundance of three major NKA alpha-isoform-like proteins (i.e., alpha1, alpha2, and alpha3) in the gills of euryhaline milkfish following salinity challenge. The protein abundance of three NKA alpha-isoform-like proteins in gills of milkfish reared in seawater (SW), fresh water (FW), as well as hypersaline water (HSW, 60 per thousand) were analyzed by immunoblotting. In the acclimation experiments, the SW group revealed significantly higher levels of NKA alpha1- and alpha3-like proteins than the FW or HSW group. Time-course experiments on milkfish that were transferred from SW to HSW revealed the abundance of branchial NKA alpha1-like and alpha3-like proteins decreased significantly after 96 and 12 hr, respectively, and no significant difference was found in NKA alpha2-like protein. Furthermore, when fish were transferred from SW to FW, the amounts of NKA alpha1- and alpha3-like proteins was significantly decreased after 96 hr. Taken together, acute and chronic changes in the abundance of branchial NKA alpha1- and alpha3-like proteins may fulfill the requirements of altering NKA activity with different Na(+) or K(+) affinity for euryhaline milkfish acclimated to environments of various salinities. 2009 Wiley-Liss, Inc.

Pegylated interferon-alpha2b plus ribavirin therapy in patients with hepatitis C and psychiatric disorders: results of a cohort study.

PubMed

Lang, Jean-Philippe; Melin, Pascal; Ouzan, Denis; Rotily, Michel; Fontanges, Thierry; Marcellin, Patrick; Chousterman, Michel; Cacoub, Patrice

2010-01-01

Hepatitis C antiviral therapies have significant psychiatric side effects. It is therefore believed that they might exacerbate mental illness in patients with pre-existing psychiatric disorders, resulting in poor adherence and response to antiviral treatment. We aimed to assess adherence to treatment, virological outcomes and mental safety in psychiatric patients, compared with non-psychiatric patients, treated for hepatitis C. A cohort study involved unselected hepatitis C patients on scheduled therapy with pegylated interferon-alpha2b and ribavirin, between 2002 and 2005 in France, and followed-up until 6 months after the end of treatment. Virological response was reported by the physician according to standard definitions and adverse events were monitored. Adherence to treatment was assessed by patient report. Among 1,860 patients, 403 (22%) had pre-existing psychiatric disorders, mostly depressive and anxiety disorders. Strict adherence was similar in psychiatric and non-psychiatric patients (35% versus 39%; P=0.20) as was the rate of sustained virological response (52% versus 51%; P=0.75). Conversely the rate of mental adverse events was higher in psychiatric patients (78% versus 57%; P<0.001). Baseline characteristics independently associated with the risk of later mental adverse events were history of depression, initial pegylated interferon-alpha2b dose and female gender. Antiviral therapy in hepatitis C patients with associated psychiatric disease appears as effective as in other patients but results in a higher rate of mental adverse events, emphasizing the need for close monitoring of these psychiatric patients.

Negative feedback regulation of human platelets via autocrine activation of the platelet-derived growth factor alpha-receptor.

PubMed

Vassbotn, F S; Havnen, O K; Heldin, C H; Holmsen, H

1994-05-13

Human platelets contain platelet-derived growth factor (PDGF) in their alpha-granules which is released during platelet exocytosis. We show by immunoprecipitation and 125I-PDGF binding experiments that human platelets have functionally active PDGF alpha-receptors, but not beta-receptors. The PDGF alpha-receptor (PDGFR-alpha) was identified as a 170-kDa glycosylated protein-tyrosine kinase as found in other cell types. Stimulation of platelets with 0.1 unit/ml thrombin resulted in a significant increase (2-5-fold) of the tyrosine phosphorylation of the PDGFR-alpha, as determined by immunoprecipitation with phosphotyrosine antiserum as well as with PDGFR-alpha antiserum. The observed thrombin-induced autophosphorylation of the PDGFR-alpha was inhibited by the addition of a neutralizing monoclonal PDGF antibody. Thus, our results suggest that the platelet PDGFR-alpha is stimulated in an autocrine manner by PDGF secreted during platelet activation. Preincubation of platelets with PDGF inhibited thrombin-induced platelet aggregation and secretion of ATP + ADP and beta-hexosaminidase. Thrombin-induced platelet aggregation was also reversed when PDGF was added 30 s after thrombin stimulation. Inhibition of the autocrine PDGF pathway during platelet activation by the PDGF antibody led to a potentiation of thrombin-induced beta-hexosaminidase secretion. Thus, the PDGFR-alpha takes part in a negative feedback regulation during platelet activation. Our demonstration of PDGF alpha-receptors on human platelets and its inhibitory function during platelet activation identifies a new possible role of PDGF in the regulation of thrombosis.

Insulin in UW solution exacerbates hepatic ischemia / reperfusion injury by energy depletion through the IRS-2 / SREBP-1c pathway.

PubMed

Li, Xian Liang; Man, Kwan; Ng, Kevin T; Lee, Terence K; Lo, Chung Mau; Fan, Sheung Tat

2004-09-01

Ischemia / reperfusion (I / R) injury is related to tissue graft energy status. Insulin, which is currently used in the University of Wisconsin (UW) preservation solution with insulin (UWI), is an anabolic hormone and was shown to exacerbate the hepatic I / R injury in our previous study. In this study, the energy status and regulation of metabolism genes by insulin were investigated in liver grafts preserved by UW solution. Insulin could significantly decrease adenosine triphosphate (ATP) level after 3 hours of preservation, as well as total adenine nucleotides (TANs) and energy charge (EC) levels. Energy regeneration deteriorated in the grafts preserved by insulin in terms of ATP and EC levels at 24 hours after transplantation. The insulin signal was transduced through the insulin receptor substrate-2 (IRS-2) pathway and the activity of IRS-2 was decreased gradually at the messenger ribonucleic acid (mRNA) level during cold preservation. Downstream targeting genes such as sterol regulatory element-binding protein-1c (SREBP-1c), glucokinase (GKC), and fatty acid synthase (FAS) genes, as well as phospho-glycogen synthase kinase-3beta (GSK-3beta) were activated and they showed the similar expression profiles during cold preservation. Lipoprotein metabolism was accelerated by insulin through upregulation of the activity of apolipoprotein C-III (Apo C-III) during cold preservation. The insulin-like growth factor-binding protein-1 pathway was inhibited during cold preservation. In conclusion, insulin in UW solution exacerbates hepatic I / R injury by energy depletion as the graft maintains its anabolic activity. The key enzyme activities of the energy-consuming process of glycogen and fatty acid synthesis as well as lipoprotein metabolism were accelerated by insulin through the IRS-2 / SREBP-1c pathway.

Expression of progesterone metabolizing enzyme genes (AKR1C1, AKR1C2, AKR1C3, SRD5A1, SRD5A2) is altered in human breast carcinoma.

PubMed

Lewis, Michael J; Wiebe, John P; Heathcote, J Godfrey

2004-06-22

Recent evidence suggests that progesterone metabolites play important roles in regulating breast cancer. Previous studies have shown that tumorous tissues have higher 5alpha-reductase (5alphaR) and lower 3alpha-hydroxysteroid oxidoreductase (3alpha-HSO) and 20alpha-HSO activities. The resulting higher levels of 5alpha-reduced progesterone metabolites such as 5alpha-pregnane-3,20-dione (5alphaP) in tumorous tissue promote cell proliferation and detachment, whereas the 4-pregnene metabolites, 4-pregnen-3alpha-ol-20-one (3alphaHP) and 4-pregnen-20alpha-ol-3-one (20alphaDHP), more prominent in normal tissue, have the opposite (anti-cancer-like) effects. The aim of this study was to determine if the differences in enzyme activities between tumorous and nontumorous breast tissues are associated with differences in progesterone metabolizing enzyme gene expression. Semi-quantitative RT-PCR was used to compare relative expression (as a ratio of 18S rRNA) of 5alphaR type 1 (SRD5A1), 5alphaR type 2 (SRD5A2), 3alpha-HSO type 2 (AKR1C3), 3alpha-HSO type 3 (AKR1C2) and 20alpha-HSO (AKR1C1) mRNAs in paired (tumorous and nontumorous) breast tissues from 11 patients, and unpaired tumor tissues from 17 patients and normal tissues from 10 reduction mammoplasty samples. Expression of 5alphaR1 and 5alphaR2 in 11/11 patients was higher (mean of 4.9- and 3.5-fold, respectively; p < 0.001) in the tumor as compared to the paired normal tissues. Conversely, expression of 3alpha-HSO2, 3alpha-HSO3 and 20alpha-HSO was higher (2.8-, 3.9- and 4.4-fold, respectively; p < 0.001) in normal than in tumor sample. The mean tumor:normal expression ratios for 5alphaR1 and 5alphaR2 were about 35-85-fold higher than the tumor:normal expression ratios for the HSOs. Similarly, in the unmatched samples, the tumor:normal ratios for 5alphaR were significantly higher than the ratios for the HSOs. The study shows changes in progesterone metabolizing enzyme gene expression in human breast carcinoma. Expression of SRD5A1 (5alphaR1) and SRD5A2 (5alphaR2) is elevated, and expression of AKR1C1 (20alpha-HSO), AKR1C2 (3alpha-HSO3) and AKR1C3 (3alpha-HSO2) is reduced in tumorous as compared to normal breast tissue. The changes in progesterone metabolizing enzyme expression levels help to explain the increases in mitogen/metastasis inducing 5alphaP and decreases in mitogen/metastasis inhibiting 3alphaHP progesterone metabolites found in breast tumor tissues. Understanding what causes these changes in expression could help in designing protocols to prevent or reverse the changes in progesterone metabolism associated with breast cancer.

Functional characterization of recombinant prefoldin complexes from a hyperthermophilic archaeon, Thermococcus sp. strain KS-1.

PubMed

Iizuka, Ryo; Sugano, Yuri; Ide, Naoki; Ohtaki, Akashi; Yoshida, Takao; Fujiwara, Shinsuke; Imanaka, Tadayuki; Yohda, Masafumi

2008-03-28

Prefoldin is a heterohexameric molecular chaperone complex that is found in the eukaryotic cytosol and also in archaea. It captures a nonnative protein and subsequently delivers it to a group II chaperonin for proper folding. Archaeal prefoldin is a heterocomplex containing two alpha subunits and four beta subunits with the structure of a double beta-barrel assembly, with six long coiled coils protruding from it like a jellyfish with six tentacles. We have studied the protein folding mechanism of group II chaperonin using those of Thermococcus sp. strain KS-1 (T. KS-1) because they exhibit high protein folding activity in vitro. We have also demonstrated functional cooperation between T. KS-1 chaperonins and prefoldin from Pyrococcus horikoshii OT3. Recent genome analysis has shown that Thermococcus kodakaraensis KOD1 contains two pairs of prefoldin subunit genes, correlating with the existence of two different chaperonin subunits. In this study, we characterized four different recombinant prefoldin complexes composed of two pairs of prefoldin subunits (alpha1, alpha2, beta1, and beta2) from T. KS-1. All of them (alpha1-beta1, alpha2-beta1, alpha1-beta2, and alpha2-beta2) exist as alpha(2)beta(4) heterohexamers and can protect several proteins from forming aggregates with different activities. We have also compared the collaborative activity between the prefoldin complexes and the cognate chaperonins. Prefoldin complexes containing the beta1 subunit interacted with the chaperonins more strongly than those with the beta2 subunit. The results suggest that Thermococcus spp. express different prefoldins for different substrates or conditions as chaperonins.

The delta-opioid receptor agonist SNC80 [(+)-4-[alpha(R)-alpha-[(2S,5R)-4-allyl-2,5-dimethyl-1-piperazinyl]-(3-methoxybenzyl)-N,N-diethylbenzamide] synergistically enhances the locomotor-activating effects of some psychomotor stimulants, but not direct dopamine agonists, in rats.

PubMed

Jutkiewicz, Emily M; Baladi, Michelle G; Folk, John E; Rice, Kenner C; Woods, James H

2008-02-01

The nonpeptidic delta-opioid agonist SNC80 [(+)-4-[alpha(R)-alpha-[(2S,5R)-4-allyl-2,5-dimethyl-1-piperazinyl]-(3-methoxybenzyl)-N,N-diethylbenzamide] produces many stimulant-like behavioral effects in rodents and monkeys, such as locomotor stimulation, generalization to cocaine in discrimination procedures, and antiparkinsonian effects. Tolerance to the locomotor-stimulating effects of SNC80 develops after a single administration of SNC80 in rats; it is not known whether cross-tolerance develops to the effects of other stimulant compounds. In the initial studies to determine whether SNC80 produced cross-tolerance to other stimulant compounds, it was discovered that amphetamine-stimulated locomotor activity was greatly enhanced in SNC80-pretreated rats. This study evaluated acute cross-tolerance between delta-opioid agonists and other locomotor-stimulating drugs. Locomotor activity was measured in male Sprague-Dawley rats implanted with radiotransmitters, and activity levels were recorded in the home cage environment. Three-hour SNC80 pretreatment produced tolerance to further delta-opioid receptor stimulation but also augmented greatly amphetamine-stimulated locomotor activity in a dose-dependent manner. Pretreatments with other delta-opioid agonists, (+)BW373U86 [(+)-4-[alpha(R)-alpha-[(2S,5R)-4-allyl-2,5-dimethyl-1-piperazinyl]-3-hydroxybenzyl]-N,N-diethylbenzamide] and oxymorphindole (17-methyl-6,7-dehydro-4,5-epoxy-3,14-dihydroxy-6,7,2',3'-indolomorphinan), also modified amphetamine-induced activity levels. SNC80 pretreatment enhanced the stimulatory effects of the dopamine/norepinephrine transporter ligands cocaine and nomifensine (1,2,3,4-tetrahydro-2-methyl-4-phenyl-8-isoquinolinanmine maleate salt), but not the direct dopamine receptor agonists SKF81297 [R-(+)-6-chloro-7,8-dihydroxy-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine hydrobromide] and quinpirole [trans-(-)-(4alphaR)-4,4a, 5,6,7,8,8a,9-octahydro-5-propyl-1H-pyrazolo[3,4-g] quinoline monohydrochloride]. In conclusion, SNC80 enhanced the locomotor-stimulating effects of monoamine transporter ligands suggesting that delta-opioid receptor activation might alter the functional activity of monoamine transporters or presynaptic monoamine terminals.

The effect of prolonged ethanol administration on central alpha 2-adrenoceptors sensitivity.

PubMed

Szmigielski, A; Szmigielska, H; Wejman, I

1989-01-01

The response of an endogenous inhibitor of protein kinases (type II inhibitor) to clonidine was used as an index of sensitivity of central alpha 2-adrenoceptors. Low doses of clonidine (20-50 micrograms/kg) induced an increase in type II inhibitor activity in the nucleus accumbens, hippocampus and in the anterior and posterior hypothalamus by stimulating presynaptic alpha 2-adrenoceptors. Stimulation of postsynaptic alpha 2-adrenoceptors by high doses of clonidine 0.5-1.0 mg/kg resulted in a dose-dependent decrease in type II inhibitor activity. Prolonged treatment with ethanol (5 g/kg/day po for 21 days) greatly reduced the action of high doses of clonidine in all the examined brain areas, suggesting subsensitivity of postsynaptic alpha 2-adrenoceptors lasting for at least 48 h after the last ethanol administration. A single dose of ethanol induced a short lasting subsensitivity of postsynaptic alpha 2-adrenoceptors in the anterior hypothalamus. 12 h after administration of alcohol the response of type II inhibitor to high doses of clonidine in this brain area was the same as in untreated rats.

Adsorption behavior of alpha -cypermethrin on cork and activated carbon.

PubMed

Domingues, Valentina F; Priolo, Giuseppe; Alves, Arminda C; Cabral, Miguel F; Delerue-Matos, Cristina

2007-08-01

Studies were undertaken to determine the adsorption behavior of alpha -cypermethrin [R)-alpha -cyano-3-phenoxybenzyl(1S)-cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate, and (S)-alpha-cyano-3-phenoxybenzyl (1R)-cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate] in solutions on granules of cork and activated carbon (GAC). The adsorption studies were carried out using a batch equilibrium technique. A gas chromatograph with an electron capture detector (GC-ECD) was used to analyze alpha -cypermethrin after solid phase extraction with C18 disks. Physical properties including real density, pore volume, surface area and pore diameter of cork were evaluated by mercury porosimetry. Characterization of cork particles showed variations thereby indicating the highly heterogeneous structure of the material. The average surface area of cork particles was lower than that of GAC. Kinetics adsorption studies allowed the determination of the equilibrium time - 24 hours for both cork (1-2 mm and 3-4 mm) and GAC. For the studied alpha -cypermethrin concentration range, GAC revealed to be a better sorbent. However, adsorption parameters for equilibrium concentrations, obtained through the Langmuir and Freundlich models, showed that granulated cork 1-2 mm have the maximum amount of adsorbed alpha-cypermethrin (q(m)) (303 microg/g); followed by GAC (186 microg/g) and cork 3-4 mm (136 microg/g). The standard deviation (SD) values, demonstrate that Freundlich model better describes the alpha -cypermethrin adsorption phenomena on GAC, while alpha -cypermethrin adsorption on cork (1-2 mm and 3-4 mm) is better described by the Langmuir. In view of the adsorption results obtained in this study it appears that granulated cork may be a better and a cheaper alternative to GAC for removing alpha -cypermethrin from water.

Therapy with proton-pump inhibitors for gastroesophageal reflux disease does not reduce the risk for severe exacerbations in COPD.

PubMed

Baumeler, Luzia; Papakonstantinou, Eleni; Milenkovic, Branislava; Lacoma, Alicia; Louis, Renaud; Aerts, Joachim G; Welte, Tobias; Kostikas, Konstantinos; Blasi, Francesco; Boersma, Wim; Torres, Antoni; Rohde, Gernot G U; Boeck, Lucas; Rakic, Janko; Scherr, Andreas; Tamm, Michael; Stolz, Daiana

2016-07-01

Gastroesophageal reflux disease (GERD) symptoms are associated with a higher risk of chronic obstructive pulmonary disease (COPD) exacerbation. We hypothesize that treatment with proton pump inhibitors reduces the risk of exacerbation in patients with stable COPD. A total of 638 patients with stable COPD for ≥6 weeks, ≥10 pack-years of smoking and Global Initiative for Chronic Obstructive Lung Disease II-IV seeking care in tertiary hospitals in eight European countries in the Predicting Outcome using Systemic Markers in Severe Exacerbations-COPD cohort was prospectively evaluated by us. Comorbidities including associated medical treatment were assessed at baseline, at exacerbation and at biannual visits. Median observation time was 24 months. The primary study outcomes were exacerbation and/or death. A total of 85 (13.3%) of COPD patients were on anti-GERD therapy. These patients had higher annual and higher severe exacerbation rates (P = 0.009 and P = 0.002), decreased quality of life (SF-36: activity score P = 0.004, St. George's Respiratory Questionnaire: physical functioning P = 0.013 and social functioning P = 0.007), higher body mass airflow obstruction, dyspnea and exercise capacity index (P = 0.033) and Modified Medical Research Council scores (P = 0.002), shorter 6-min walking distance (P = 0.0004) and a higher adjusted Charlson score (P < 0.0001). Anti-GERD therapy was associated with a shorter time to severe exacerbation (HR 2.05 95% CI 1.37-3.08). Using three multivariable Cox-regression models, this association was independent of the following: (i) adjusted Charlson score and FEV1% predicted (HR 1.91 95% CI 1.26-2.90); (ii) adjusted Charlson score, body mass, airflow obstruction, dyspnea and exercise capacity index and Modified Medical Research Council (HR 1.62 95% CI 1.04-2.54); and (iii) adjusted Charlson score, FEV1% predicted and nine classes of medication for comorbidities (HR 1.63 95% CI 1.04-2.53). These findings suggest that patients with stable COPD receiving acid-suppressive therapy with proton pump inhibitors remain at high risk of frequent and severe exacerbations. © 2016 Asian Pacific Society of Respirology.

Regulation of the oncodevelopmental expression of type 1 chain ABH and Lewis(b) blood group antigens in human colon by alpha-2-L-fucosylation.

PubMed Central

Orntoft, T F; Greenwell, P; Clausen, H; Watkins, W M

1991-01-01

Blood group antigen expression in the distal human colon is related to the development of the organ and is modified by malignant transformation. To elucidate the biochemical basis for these changes, we have (a) analysed the activity of glycosyltransferases coded for by the H, Se, Le, X, and A genes, in tissue biopsy specimens from normal and malignant proximal and distal human colon; (b) characterised the glycosphingolipids expressed in the various regions of normal and malignant colon by immunostaining of high performance thin layer chromatography plates; and (c) located the antigens on tissue sections from the same subjects by immunohistochemistry. In both secretors and non-secretors we found a significantly higher activity of alpha-2-L-fucosyltransferases in carcinomatous rectal tissue than in tissue from normal subjects, whereas the other transferase activities studied showed no significant differences. The acceptor substrate specificity suggested that both the Se and the H gene dependent alpha-2-L-fucosyltransferases are increased in carcinomas. In non-malignant tissue the only enzyme which showed appreciably higher activity in caecum than in rectum was alpha-2-L-fucosyltransferase. Immunochemistry and immunohistochemistry showed alpha-2-L-fucosylated structures in normal caecum from secretors and in tumour tissue from both secretors and non-secretors. We conclude that the alpha-2-L-fucosyltransferases control the expression of ABH, and Lewis(b) structures in normal and malignant colon. Images Figure 4 PMID:1826491

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

Liebhaber, S.A.; Weiss, I.; Cash, F.E.

Synthesis of normal human hemoglobin A, {alpha}{sub 2}{beta}{sub 2}, is based upon balanced expression of genes in the {alpha}-globin gene cluster on chromosome 15 and the {beta}-globin gene cluster on chromosome 11. Full levels of erythroid-specific activation of the {beta}-globin cluster depend on sequences located at a considerable distance 5{prime} to the {beta}-globin gene, referred to as the locus-activating or dominant control region. The existence of an analogous element(s) upstream of the {alpha}-globin cluster has been suggested from observations on naturally occurring deletions and experimental studies. The authors have identified an individual with {alpha}-thalassemia in whom structurally normal {alpha}-globin genesmore » have been inactivated in cis by a discrete de novo 35-kilobase deletion located {approximately}30 kilobases 5{prime} from the {alpha}-globin gene cluster. They conclude that this deletion inactivates expression of the {alpha}-globin genes by removing one or more of the previously identified upstream regulatory sequences that are critical to expression of the {alpha}-globin genes.« less

A systematic review of the role of vitamin insufficiencies and supplementation in COPD.

PubMed

Tsiligianni, Ioanna G; van der Molen, Thys

2010-12-06

Pulmonary inflammation, oxidants-antioxidants imbalance, as well as innate and adaptive immunity have been proposed as playing a key role in the development of COPD. The role of vitamins, as assessed either by food frequency questionnaires or measured in serum levels, have been reported to improve pulmonary function, reduce exacerbations and improve symptoms. Vitamin supplements have therefore been proposed to be a potentially useful additive to COPD therapy. A systematic literature review was performed on the association of vitamins and COPD. The role of vitamin supplements in COPD was then evaluated. The results of this review showed that various vitamins (vitamin C, D, E, A, beta and alpha carotene) are associated with improvement in features of COPD such as symptoms, exacerbations and pulmonary function. High vitamin intake would probably reduce the annual decline of FEV1. There were no studies that showed benefit from vitamin supplementation in improved symptoms, decreased hospitalization or pulmonary function.

Tyrosine kinase inhibitors suppress prostaglandin F2alpha-induced phosphoinositide hydrolysis, Ca2+ elevation and contraction in iris sphincter smooth muscle.

PubMed

Yousufzai, S Y; Abdel-Latif, A A

1998-11-06

We investigated the effects of the protein tyrosine kinase inhibitors, genistein, tyrphostin 47, and herbimycin on prostaglandin F2alpha- and carbachol-induced inositol-1,4,5-trisphosphate (IP3) production, [Ca2+]i mobilization and contraction in cat iris sphincter smooth muscle. Prostaglandin F2alpha and carbachol induced contraction in a concentration-dependent manner with EC50 values of 0.92 x 10(-9) and 1.75 x 10(-8) M, respectively. The protein tyrosine kinase inhibitors blocked the stimulatory effects of prostaglandin F2alpha, but not those evoked by carbachol, on IP3 accumulation, [Ca2+]i mobilization and contraction, suggesting involvement of protein tyrosine kinase activity in the physiological actions of the prostaglandin. Daidzein and tyrphostin A, inactive negative control compounds for genistein and tyrphostin 47, respectively, were without effect. Latanoprost, a prostaglandin F2alpha analog used as an antiglaucoma drug, induced contraction and this effect was blocked by genistein. Genistein (10 microM) markedly reduced (by 67%) prostaglandin F2alpha-stimulated increase in [Ca2+]i but had little effect on that of carbachol in cat iris sphincter smooth muscle cells. Vanadate, a potent inhibitor of protein tyrosine phosphatase, induced a slow gradual muscle contraction in a concentration-dependent manner with an EC50 of 82 microM and increased IP3 generation in a concentration-dependent manner with an EC50 of 90 microM. The effects of vanadate were abolished by genistein (10 microM). Wortmannin, a myosin light chain kinase inhibitor, reduced prostaglandin F2alpha- and carbachol-induced contraction, suggesting that the involvement of protein tyrosine kinase activity may lie upstream of the increases in [Ca2+]i evoked by prostaglandin F2alpha. Further studies aimed at elucidating the role of protein tyrosine kinase activity in the coupling mechanism between prostaglandin F2alpha receptor activation and increases in intracellular Ca2+ mobilization and identifying the tyrosine-phosphorylated substrates will provide important information about the role of protein tyrosine kinase in the mechanism of smooth muscle contraction, as well as about the mechanism of the intraocular pressure lowering effect of the prostaglandin in glaucoma patients.

Mechanical stimulation of skeletal muscle cells mitigates glucocorticoid-induced decreases in prostaglandin production and prostaglandin synthase activity

NASA Technical Reports Server (NTRS)

Chromiak, J. A.; Vandenburgh, H. H.

1994-01-01

The glucocorticoid dexamethasone (Dex) induces a decline in protein synthesis and protein content in tissue cultured, avian skeletal muscle cells, and this atrophy is attenuated by repetitive mechanical stretch. Since the prostaglandin synthesis inhibitor indomethacin mitigated this stretch attenuation of muscle atrophy, the effects of Dex and mechanical stretch on prostaglandin production and prostaglandin H synthase (PGHS) activity were examined. In static cultures, 10(-8) M Dex reduced PGF2 alpha production 55-65% and PGE2 production 84-90% after 24-72 h of incubation. Repetitive 10% stretch-relaxations of non-Dex-treated cultures increased PGF2 alpha efflux 41% at 24 h and 276% at 72 h, and increased PGE2 production 51% at 24 h and 236% at 72 h. Mechanical stimulation of Dex-treated cultures increased PGF2 alpha production 162% after 24 h, returning PGF2 alpha efflux to the level of non-Dex-treated cultures. At 72 h, stretch increased PGF2 alpha efflux 65% in Dex-treated cultures. Mechanical stimulation of Dex-treated cultures also increased PGE2 production at 24 h, but not at 72 h. Dex reduced PGHS activity in the muscle cultures by 70% after 8-24 h of incubation, and mechanical stimulation of the Dex-treated cultures increased PGHS activity by 98% after 24 h. Repetitive mechanical stimulation attenuates the catabolic effects of Dex on cultured skeletal muscle cells in part by mitigating the Dex-induced declines in PGHS activity and prostaglandin production.

Glucocorticoids suppress tumor necrosis factor-alpha expression by human monocytic THP-1 cells by suppressing transactivation through adjacent NF-kappa B and c-Jun-activating transcription factor-2 binding sites in the promoter.

PubMed

Steer, J H; Kroeger, K M; Abraham, L J; Joyce, D A

2000-06-16

Glucocorticoid drugs suppress tumor necrosis factor-alpha (TNF-alpha) synthesis by activated monocyte/macrophages, contributing to an anti-inflammatory action in vivo. In lipopolysaccharide (LPS)-activated human monocytic THP-1 cells, glucocorticoids acted primarily on the TNF-alpha promoter to suppress a burst of transcriptional activity that occurred between 90 min and 3 h after LPS exposure. LPS increased nuclear c-Jun/ATF-2, NF-kappaB(1)/Rel-A, and Rel-A/C-Rel transcription factor complexes, which bound specifically to oligonucleotide sequences from the -106 to -88 base pair (bp) region of the promoter. The glucocorticoid, dexamethasone, suppressed nuclear binding activity of these complexes prior to and during the critical phase of TNF-alpha transcription. Site-directed mutagenesis in TNF-alpha promoter-luciferase reporter constructs showed that the adjacent c-Jun/ATF-2 (-106 to -99 bp) and NF-kappaB (-97 to -88 bp) binding sites each contributed to the LPS-stimulated expression. Mutating both sites largely prevented dexamethasone from suppressing TNF-alpha promoter-luciferase reporters. LPS exposure also increased nuclear Egr-1 and PU.1 abundance. The Egr-1/Sp1 (-172 to -161 bp) binding sites and the PU.1-binding Ets site (-116 to -110 bp) each contributed to the LPS-stimulated expression but not to glucocorticoid response. Dexamethasone suppressed the abundance of the c-Fos/c-Jun complex in THP-1 cell nuclei, but there was no direct evidence for c-Fos/c-Jun transactivation through sites in the -172 to -52 bp region. Small contributions to glucocorticoid response were attributable to promoter sequences outside the -172 to -88 bp region and to sequences in the TNF-alpha 3'-untranslated region. We conclude that glucocorticoids suppress LPS-stimulated secretion of TNF-alpha from human monocytic cells largely through antagonizing transactivation by c-Jun/ATF-2 and NF-kappaB complexes at binding sites in the -106 to -88 bp region of the TNF-alpha promoter.

Overexpression of {alpha}-catenin increases osteoblastic differentiation in mouse mesenchymal C3H10T1/2 cells

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

Kim, Dohee; Yang, Jae-Yeon; Shin, Chan Soo, E-mail: csshin@snu.ac.kr

2009-05-15

{alpha}- and {beta}-Catenin link cadherins to the actin-based cytoskeleton at adherens junctions and regulate cell-cell adhesion. Although roles of cadherins and canonical Wnt-/{beta}-catenin-signaling in osteoblastic differentiation have been extensively studied, the role of {alpha}-catenin is not known. Murine embryonic mesenchymal stem cells, C3H10T1/2 cells, were transduced with retrovirus encoding {alpha}-catenin (MSCV-{alpha}-catenin-HA-GFP). In the presence of Wnt-3A conditioned medium or osteogenic medium ({beta}-glycerol phosphate and ascorbic acid), cells overexpressing {alpha}-catenin showed enhanced osteoblastic differentiation as measured by alkaline phosphatase (ALP) staining and ALP activity assay compared to cells transduced with empty virus (MSCV-GFP). In addition, mRNA expression of osteocalcin and Runx2more » was significantly increased compared to control. Cell aggregation assay revealed that {alpha}-catenin overexpression has significantly increased cell-cell aggregation. However, cellular {beta}-catenin levels (total, cytoplasmic-nuclear ratio) and {beta}-catenin-TCF/LEF transcriptional activity did not change by overexpression of {alpha}-catenin. Knock-down of {alpha}-catenin using siRNA decreased osteoblastic differentiation as measured by ALP assay. These results suggest that {alpha}-catenin overexpression increases osteoblastic differentiation by increasing cell-cell adhesion rather than Wnt-/{beta}-catenin-signaling.« less

Unique regional distribution of delta 4-3-ketosteroid-5 alpha-oxidoreductase and associated epididymal morphology in the marsupial, Didelphis virginiana.

PubMed

Kelce, W R; Krause, W J; Ganjam, V K

1987-09-01

The epididymal epithelial ultrastructure has been described in the adult male North American opossum, Didelphis virginiana. Morphological results have suggested that absorptive activity is prominent in the proximal epididymal region by virtue of numerous microvilli, an endocytotic complex, dense granules, and multivesicular bodies in the apical cytoplasm. In contrast, the middle and distal epididymal regions exhibit ultrastructural features indicative of protein synthesis such as large invaginated euchromatic nuclei, large nucleoli, and increased amounts of granular endoplasmic reticulum. It is in the middle and distal epididymal regions where sperm head rotation and sperm pairing take place. Epididymal delta 4-3-ketosteroid-5 alpha-oxidoreductase (5 alpha-reductase) activity also has been measured. It has been found that the level of enzyme activity differs significantly (p less than 0.01) between the proximal, middle, and distal epididymal regions. Enzyme-specific activity has been found to be highest in the middle region (47.6 +/- 5.4 picomoles 5 alpha-reduced androgens formed/b/mg protein), lower in the distal region (18.3 +/- 0.7 picomoles 5 alpha-reduced androgens formed/b/mg protein), with little activity (2.4 +/- 1.2 picomoles 5 alpha-reduced androgens formed/h/mg protein) found in the proximal epididymal region. This regional distribution of enzyme activity differs markedly from that reported for eutherian mammals. Both the suggested epididymal protein synthetic and secretory activity and the level of epididymal 5 alpha-reductase activity appear to correlate regionally with the morphological changes that occur in the opossum spermatozoa as they transit the epididymis.

Isolation of a new anti-inflammatory 20, 21, 22, 23, 24, 25, 26, 27-octanorcucurbitacin-type triterpene from Ibervillea sonorae.

PubMed

Jardón-Delgado, Angel; Magos-Guerrero, Gil Alfonso; Martínez-Vázquez, Mariano

2014-01-01

A new cucurbitane-type triterpene, 20, 21, 22, 23, 24, 25, 26, 27-octanorcucurbita-5-ene-3, 11, 16-trione (1), named kinoin D, was isolated from the roots of the medicinal plant Ibervillea sonorae, (wereque). The structure of 1 was established on the basis of extensive NMR and MS studies. In addition, the known kinoins B (3) and C (5) were isolated, as were 16alpha-20,25-trihydroxy-3alpha-(2-O-alpha-L-rhamnopyranosiyl-D-glucopyranosyloxy)-(10alpha)-cucurbit-5-en-11,22-dione (6), (22S)-16alpha,22-diacetoxy-20,25-dihydroxy-3alpha-[3,4,6-tri-O-acetyl-2-O-(2,3,4-tri-O-acetyl-alpha-L-rhamnopyranosyl)-beta-glucopyranosyl]-(10alpha)-cucurbita-5,23t-dien-11-one (7) and 16alpha-acetoxy-20,25-dihydroxy-3alpha-[3,4,6-tri-O-acetyl-2-O-(2,3,4,-tri-O-acetyl-alpha-L-rhamnopyranosyl)-beta-D-glucopyranosyl]-(10alpha)-cucurbita-5-ene-11,22-dione (8). Compound 1 exhibited anti-inflammatory activity in TPA-induced edema in mice.

[Vitamin E activity of some alpha-tocopherol derivatives and their effect on the ubiquinone level in rat liver in vitro].

PubMed

Donchenko, G V; Kovalenko, V N; Zolotashko, O M; Makovetskiĭ, V P; Basalkevich, E D; Sivachek, T E; Svishchuk, A A; Khalmuradov, A G

1979-01-01

An addition of alpha-tocopherol (I) and its synthetic derivatives (alpha-tocopheryl quinone (II), its short-chained analog (III), alpha-tocopherol lactone (IV), and short-chained alpha-tocopheryl acetate (V)) to the homogenized liver of vitamin E deficient rats resulted in a significant increase of ubiquinone after 2 hour incubation. Activity of the above derivatives (II-V) was not associated directly with their transformation into I or with a noticeable increase of the I content. There is a certain correlation between the chemical structure and the level of vitamin E activity of alpha-tocopherol derivatives that led to an increase in the ubiquinone content and prevented the decrease of tissue respiration and termination of pregnancy in rats.

Cytotoxicity of cardenolides and cardenolide glycosides from Asclepias curassavica.

PubMed

Li, Jun-Zhu; Qing, Chen; Chen, Chang-Xiang; Hao, Xiao-Jiang; Liu, Hai-Yang

2009-04-01

A new cardenolide, 12beta,14beta-dihydroxy-3beta,19-epoxy-3alpha-methoxy-5alpha-card-20(22)-enolide (6), and a new doubly linked cardenolide glycoside, 12beta-hydroxycalotropin (13), together with eleven known compounds, coroglaucigenin (1), 12beta-hydroxycoroglaucigenin (2), calotropagenin (3), desglucouzarin (4), 6'-O-feruloyl-desglucouzarin (5), calotropin (7), uscharidin (8), asclepin (9), 16alpha-hydroxyasclepin (10), 16alpha-acetoxycalotropin (11), and 16alpha-acetoxyasclepin (12), were isolated from the aerial part of ornamental milkweed, Asclepias curassavica and chemically elucidated through spectral analyses. All the isolates were evaluated for their cytotoxic activity against HepG2 and Raji cell lines. The results showed that asclepin (9) had the strongest cytotoxic activity with an IC(50) value of 0.02 microM against the two cancer cell lines and the new compound 13 had significant cytotoxic activity with IC(50) values of 0.69 and 1.46 microM, respectively.

Nicotine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone induce cyclooxygenase-2 activity in human gastric cancer cells: Involvement of nicotinic acetylcholine receptor (nAChR) and {beta}-adrenergic receptor signaling pathways

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

Shin, Vivian Yvonne; Jin, H.C.; Ng, Enders K.O.

Induction of cyclooxygenase-2 (COX-2) associates with cigarette smoke exposure in many malignancies. Nicotine and its derivative, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), are the two important components in cigarette smoke that contributes to cancer development. However, the molecular mechanism(s) by which nicotine or NNK promotes gastric carcinogenesis remains largely unknown. We found that nicotine and NNK significantly enhanced cell proliferation in AGS cells that expressed both alpha7 nicotinic acetylcholine receptor ({alpha}7 nAChR) and {beta}-adrenergic receptors. Treatment of cells with {alpha}-bungarotoxin ({alpha}-BTX, {alpha}7nAChR antagonist) or propranolol ({beta}-adrenergic receptor antagonist) blocked NNK-induced COX-2/PGE{sub 2} and cell proliferation, while nicotine-mediated cell growth and COX-2/PGE{sub 2} induction canmore » only be suppressed by propranolol, but not {alpha}-BTX. Moreover, in contrast to the dependence of growth promoting effect of nicotine on Erk activation, inhibitor of p38 mitogen-activated protein kinase (MAPK) repressed NNK-induced COX-2 upregulation and resulted in suppression of cell growth. In addition, nicotine and NNK mediated COX-2 induction via different receptors to modulate several G1/S transition regulatory proteins and promote gastric cancer cell growth. Selective COX-2 inhibitor (SC-236) caused G1 arrest and abrogated nicotine/NNK-induced cell proliferation. Aberrant expression of cyclin D1 and other G1 regulatory proteins are reversed by blockade of COX-2. These results pointed to the importance of adrenergic and nicotinic receptors in gastric tumor growth through MAPK/COX-2 activation, which may perhaps provide a chemoprevention strategy for cigarette smoke-related gastric carcinogenesis.« less

Alpha Air Sample Counting Efficiency Versus Dust Loading: Evaluation of a Large Data Set

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

Hogue, M. G.; Gause-Lott, S. M.; Owensby, B. N.

Dust loading on air sample filters is known to cause a loss of efficiency for direct counting of alpha activity on the filters, but the amount of dust loading and the correction factor needed to account for attenuated alpha particles is difficult to assess. In this paper, correction factors are developed by statistical analysis of a large database of air sample results for a uranium and plutonium processing facility at the Savannah River Site. As is typically the case, dust-loading data is not directly available, but sample volume is found to be a reasonable proxy measure; the amount of dustmore » loading is inferred by a combination of the derived correction factors and a Monte Carlo model. The technique compares the distribution of activity ratios [beta/(beta + alpha)] by volume and applies a range of correction factors on the raw alpha count rate. The best-fit results with this method are compared with MCNP modeling of activity uniformly deposited in the dust and analytical laboratory results of digested filters. Finally, a linear fit is proposed to evenly-deposited alpha activity collected on filters with dust loading over a range of about 2 mg cm -2 to 1,000 mg cm -2.« less

Alpha Air Sample Counting Efficiency Versus Dust Loading: Evaluation of a Large Data Set

DOE PAGES

Hogue, M. G.; Gause-Lott, S. M.; Owensby, B. N.; ...

2018-03-03

Dust loading on air sample filters is known to cause a loss of efficiency for direct counting of alpha activity on the filters, but the amount of dust loading and the correction factor needed to account for attenuated alpha particles is difficult to assess. In this paper, correction factors are developed by statistical analysis of a large database of air sample results for a uranium and plutonium processing facility at the Savannah River Site. As is typically the case, dust-loading data is not directly available, but sample volume is found to be a reasonable proxy measure; the amount of dustmore » loading is inferred by a combination of the derived correction factors and a Monte Carlo model. The technique compares the distribution of activity ratios [beta/(beta + alpha)] by volume and applies a range of correction factors on the raw alpha count rate. The best-fit results with this method are compared with MCNP modeling of activity uniformly deposited in the dust and analytical laboratory results of digested filters. Finally, a linear fit is proposed to evenly-deposited alpha activity collected on filters with dust loading over a range of about 2 mg cm -2 to 1,000 mg cm -2.« less

Reactivation of the chloroplast CF1-ATPase beta subunit by trace amounts of the CF1 alpha subunit suggests a chaperonin-like activity for CF1 alpha.

PubMed

Avni, A; Avital, S; Gromet-Elhanan, Z

1991-04-25

Incubation of tobacco and lettuce thylakoids with 2 M LiCl in the presence of MgATP removes the beta subunit from their CF1-ATPase (CF1 beta) together with varying amounts of the CF1 alpha subunit (CF1 alpha). These 2 M LiCl extracts, as with the one obtained from spinach thylakoids (Avital, S., and Gromet-Elhanan, Z. (1991) J. Biol. Chem. 266, 7067-7072), could form active hybrid ATPases when reconstituted into inactive beta-less Rhodospirillum rubrum chromatophores. Pure CF1 beta fractions that have been isolated from these extracts could not form such active hybrids by themselves, but could do so when supplemented with trace amounts (less than 5%) of CF1 alpha. A mitochondrial F1-ATPase alpha subunit was recently reported to be a heat-shock protein, having two amino acid sequences that show a highly conserved identity with sequences found in molecular chaperones (Luis, A. M., Alconada, A., and Cuezva, J. M. (1990) J. Biol. Chem. 265, 7713-7716). These sequences are also conserved in CF1 alpha isolated from various plants, but not in F1 beta subunits. The above described reactivation of CF1 beta by trace amounts of CF1 alpha could thus be due to a chaperonin-like function of CF1 alpha, which involves the correct, active folding of isolated pure CF1 beta.

Structural elucidation of novel phosphocholine-containing glycosylinositol-phosphoceramides in filamentous fungi and their induction of cell death of cultured rice cells.

PubMed Central

Aoki, Kazuhiro; Uchiyama, Ryosuke; Itonori, Saki; Sugita, Mutsumi; Che, Fang-Sik; Isogai, Akira; Hada, Noriyasu; Hada, Junko; Takeda, Tadahiro; Kumagai, Hidehiko; Yamamoto, Kenji

2004-01-01

Novel ZGLs (zwitterionic glycosphingolipids) have been found in and extracted from the mycelia of filamentous fungi ( Acremonium sp.) isolated from soil. Five ZGLs (ZGL1-ZGL5) were structurally elucidated by sugar compositional analysis, methylation analysis, periodate oxidation, matrix-assisted laser-desorption ionization-time-of-flight MS, (1)H-NMR spectroscopy and fast-atom bombardment MS. Their chemical structures were as follows: GlcN(alpha1-2)Ins1-P-1Cer (ZGL1), Man(alpha1-6)GlcN(alpha1-2)Ins1-P-1Cer (ZGL2), Man(alpha1-6)Man(alpha1-6)GlcN(alpha1-2)Ins1-P-1Cer (ZGL3), PC-->6Man(alpha1-6)GlcN(alpha1-2)Ins1- P -1Cer (ZGL4), and PC-->6Man(alpha1-6)Man(alpha1-6)GlcN(alpha1-2)Ins1-P-1Cer (ZGL5) (where Cer is ceramide and PC is phosphocholine). In addition, one acidic glycosphingolipid, which was the precursor of ZGLs, was also characterized as inositol-phosphoceramide. The core structure of the ZGLs, GlcN(alpha1-2)Ins1- P, is rather different from those found in other fungi, such as Man(alpha1-2)Ins1- P and Man(alpha1-6)Ins1- P. Interestingly, the terminal mannose residue of ZGL4 and ZGL5 was modified further with a PC group. The presence of PC-containing glycosylinositol-phosphoceramides has not been reported previously in any organism. The ceramide constituents of both ZGLs and acidic glycosphingolipid were essentially the same, and consisted of a 4-hydroxyoctadecasphinganine (phytosphingosine) as the sole sphingoid base and 2-hydroxytetracosanoic acid (>90%) as the major fatty acid. ZGLs were found to cause cell death in suspensions of cultured rice cells. The cell death-inducing activity of ZGLs is probably due to the characteristic glycan moiety of Man(alpha1-6)GlcN, and PC-containing ZGLs had high activity. This study is the first to demonstrate that fungal glycosylinositol-phosphoceramides induce cell death in cultured rice cells. PMID:14583095

Calcineurin signaling and PGC-1alpha expression are suppressed during muscle atrophy due to diabetes.

PubMed

Roberts-Wilson, Tiffany K; Reddy, Ramesh N; Bailey, James L; Zheng, Bin; Ordas, Ronald; Gooch, Jennifer L; Price, S Russ

2010-08-01

PGC-1alpha is a transcriptional coactivator that controls energy homeostasis through regulation of glucose and oxidative metabolism. Both PGC-1alpha expression and oxidative capacity are decreased in skeletal muscle of patients and animals undergoing atrophy, suggesting that PGC-1alpha participates in the regulation of muscle mass. PGC-1alpha gene expression is controlled by calcium- and cAMP-sensitive pathways. However, the mechanism regulating PGC-1alpha in skeletal muscle during atrophy remains unclear. Therefore, we examined the mechanism responsible for decreased PGC-1alpha expression using a rodent streptozotocin (STZ) model of chronic diabetes and atrophy. After 21days, the levels of PGC-1alpha protein and mRNA were decreased. We examined the activation state of CREB, a potent activator of PGC-1alpha transcription, and found that phospho-CREB was paradoxically high in muscle of STZ-rats, suggesting that the cAMP pathway was not involved in PGC-1alpha regulation. In contrast, expression of calcineurin (Cn), a calcium-dependent phosphatase, was suppressed in the same muscles. PGC-1alpha expression is regulated by two Cn substrates, MEF2 and NFATc. Therefore, we examined MEF2 and NFATc activity in muscles from STZ-rats. Target genes MRF4 and MCIP1.4 mRNAs were both significantly reduced, consistent with reduced Cn signaling. Moreover, levels of MRF4, MCIP1.4, and PGC-1alpha were also decreased in muscles of CnAalpha-/- and CnAbeta-/- mice without diabetes indicating that decreased Cn signaling, rather than changes in other calcium- or cAMP-sensitive pathways, were responsible for decreased PGC-1alpha expression. These findings demonstrate that Cn activity is a major determinant of PGC-1alpha expression in skeletal muscle during diabetes and possibly other conditions associated with loss of muscle mass.

Anti-endotoxic shock effects of cyproheptadine in rats.

PubMed

Wang, Lizan; Zhang, Qingzhu; Hu, Xiuzhou; Lun, Ning; Wang, Baosheng; Zhu, Fanhe

2002-03-01

To investigate the antagonistic effect and mechanism of the effect of cyproheptadine (Cyp) on endotoxic shock in rats. Endotoxic shock was produced in rats by i.v. injection of lipopolysaccharides (LPS) (5 mg/kg). Tumor necrosis factor (TNF(alpha)) mRNA expression was assessed by Northern blot. Plasma TNF(alpha) content was measured by radioimmunoassay. Plasma superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were measured. The intracellular free calcium concentration ([Ca(2+)](i)) in single endothelial cells was determined by laser scanning confocal microscopy (LSCM). Cyp 5 mg/kg injected immediately after i.v. LPS raised the mean arterial blood pressure (MABP) of shocked rats and improved their 24 h survival rate. Meanwhile, Cyp markedly decreased TNF(alpha) mRNA levels in rat liver (18 +/- 10 vs. LPS + saline 38 +/- 10, P < 0.01) as well as plasma TNF(alpha) content [(7.8 +/- 2.4) microg/L vs. LPS + saline (21.5 +/- 3.2) microg/L, P < 0.01)]. It enhanced plasma SOD activity [(1037.2 +/- 112.8) NU/L vs LPS + saline (615.4 +/- 92.6) NU/L, P < 0.01], reduced the MDA content [(5.2 +/- 1.1) micromol/L vs. LPS + saline (9.8 +/- 1.5) micromol/L, P < 0.01], and inhibited TNF(alpha)-induced [Ca(2+)](i) elevation. Cyp exerts an anti-endotoxic shock effect by inhibiting TNF(alpha) gene expression, enhancing SOD activity, reducing lipid peroxidation, and preventing [Ca(2+)](i) overload.

Network Oscillations Drive Correlated Spiking of ON and OFF Ganglion Cells in the rd1 Mouse Model of Retinal Degeneration

PubMed Central

Margolis, David J.; Gartland, Andrew J.; Singer, Joshua H.; Detwiler, Peter B.

2014-01-01

Following photoreceptor degeneration, ON and OFF retinal ganglion cells (RGCs) in the rd-1/rd-1 mouse receive rhythmic synaptic input that elicits bursts of action potentials at ∼10 Hz. To characterize the properties of this activity, RGCs were targeted for paired recording and morphological classification as either ON alpha, OFF alpha or non-alpha RGCs using two-photon imaging. Identified cell types exhibited rhythmic spike activity. Cross-correlation of spike trains recorded simultaneously from pairs of RGCs revealed that activity was correlated more strongly between alpha RGCs than between alpha and non-alpha cell pairs. Bursts of action potentials in alpha RGC pairs of the same type, i.e. two ON or two OFF cells, were in phase, while bursts in dissimilar alpha cell types, i.e. an ON and an OFF RGC, were 180 degrees out of phase. This result is consistent with RGC activity being driven by an input that provides correlated excitation to ON cells and inhibition to OFF cells. A2 amacrine cells were investigated as a candidate cellular mechanism and found to display 10 Hz oscillations in membrane voltage and current that persisted in the presence of antagonists of fast synaptic transmission and were eliminated by tetrodotoxin. Results support the conclusion that the rhythmic RGC activity originates in a presynaptic network of electrically coupled cells including A2s via a Na+-channel dependent mechanism. Network activity drives out of phase oscillations in ON and OFF cone bipolar cells, entraining similar frequency fluctuations in RGC spike activity over an area of retina that migrates with changes in the spatial locus of the cellular oscillator. PMID:24489706

Effects of the pesticide amitraz and its metabolite BTS 27271 on insulin and glucagon secretion from the perfused rat pancreas: involvement of alpha2D-adrenergic receptors.

PubMed

Abu-Basha, E A; Yibchok-Anun, S; Hopper, D L; Hsu, W H

1999-11-01

The study purpose was to investigate the direct effect of amitraz, a formamidine insecticide/acaricide, and its active metabolite BTS 27271 on insulin and glucagon secretion from the perfused rat pancreas. Amitraz and BTS 27271 (0.01, 0.1, 1, and 10 micromol/L) inhibited insulin secretion in a concentration-dependent manner. Amitraz increased glucagon secretion at 10 micromol/L, whereas BTS 27271 increased glucagon secretion at 1 and 10 micromol/L. Amitraz- and BTS 27271-induced decreases in insulin secretion and increases in glucagon secretion were not abolished during the 10-minute washout period. During the arginine treatment, both amitraz and BTS 27271 groups (0.1, 1, and 10 micromol/L) had lower insulin secretion and higher glucagon secretion than the control group. Idazoxan, an alpha2A/2D-adrenergic receptor (AR) antagonist, prevented the inhibitory effect of amitraz on insulin secretion in a concentration-dependent manner, but prazosin, an alpha1- and alpha2B/2C-AR antagonist, failed to antagonize the effect of amitraz. These results demonstrate that (1) amitraz and BTS 27271 inhibit insulin and stimulate glucagon secretion from the perfused rat pancreas, (2) amitraz inhibits insulin secretion by activation of alpha2D-ARs, since rats have alpha2D- but not alpha2A-ARs, and (3) amitraz and BTS 27271 may have a high binding affinity to the alpha2D-ARs of pancreatic islets.

Regulation by magnesium of potato tuber mitochondrial respiratory activities.

PubMed

Vicente, Joaquim A F; Madeira, Vítor M C; Vercesi, Anibal E

2004-12-01

Dehydrogenase activities of potato tuber mitochondria and corresponding phosphorylation rates were measured for the dependence on external and mitochondrial matrix Mg2+. Magnesium stimulated state 3 and state 4 respiration, with significantly different concentrations of matrix Mg2+ required for optimal activities of the several substrates. Maximal stimulation of respiration with all substrates was obtained at 2-mM external Mg2+. However, respiration of malate, citrate, and alpha-ketoglutarate requires at least 4-mM Mg2+ inside mitochondria for maximization of dehydrogenase activities. The phosphorylation system, requires a low level of internal Mg2+ (0.25 mM) to reach high activity, as judged by succinate-dependent respiration. However, mitochondria respiring on citrate or alpha-ketoglutarate only sustain high levels of phosphorylation with at least 4-mM matrix Mg2+. Respiration of succinate is active without external and matrix Mg2+, although stimulated by the cation. Respiration of alpha-ketoglutarate was strictly dependent on external Mg2+ required for substrate transport into mitochondria, and internal Mg2+ is required for dehydrogenase activity. Respiration of citrate and malate also depend on internal Mg2+ but, unlike alpha-ketoglutarate, some activity still remains without external Mg2+. All the substrates revealed insensitive to external and internal mitochondrial Ca2+, except the exogenous NADH dehydrogenase, which requires either external Ca2+ or Mg2+ for detectable activity. Calcium is more efficient than Mg2+, both having cumulative stimulation. Unlike Ca2+, Mn2+ could substitute for Mg2+, before and after addition of A23, showing its ability to regulate phosphorylation and succinate dehydrogenase activities, with almost the same efficiency as Mg2+.

alpha-Adrenoceptor and opioid receptor modulation of clonidine-induced antinociception.

PubMed Central

Sierralta, F.; Naquira, D.; Pinardi, G.; Miranda, H. F.

1996-01-01

1. The antinociceptive action of clonidine (Clon) and the interactions with alpha 1, alpha 2 adrenoceptor and opioid receptor antagonists was evaluated in mice by use of chemical algesiometric test (acetic acid writhing test). 2. Clon produced a dose-dependent antinociceptive action and the ED50 for intracerebroventricular (i.c.v.) was lower than for intraperitoneal (i.p.) administration (1 ng kg-1 vs 300 ng kg-1). The parallelism of the dose-response curves indicates activation of a common receptor subtype. 3. Systemic administration of prazosin and terazosin displayed antinociceptive activity. Pretreatment with prazosin produced a dual action: i.c.v. Clon effect did not change, and i.p. Clon effect was enhanced. Yohimbine i.c.v. or i.p. did not induce antinonciception, but antagonized Clon-induced activity. These results suggest that alpha 1- and alpha 2-adrenoceptors, either located at the pre- and/or post-synaptic level, are involved in the control of spinal antinociception. 4. Naloxone (NX) and naltrexone (NTX) induced antinociceptive effects at low doses (microgram kg-1 range) and a lower antinociceptive effect at higher doses (mg kg-1 range). Low doses of NX or NTX antagonized Clon antinociception, possibly in relation to a preferential mu opioid receptor antagonism. In contrast, high doses of NX or NTX increased the antinociceptive activity of Clon, which could be due to an enhanced inhibition of the release of substance P. 5. The results obtained in the present work suggest the involvement of alpha 1-, alpha 2-adrenoceptor and opioid receptors in the modulation of the antinociceptive activity of clonidine, which seems to be exerted either at spinal and/or supraspinal level. PMID:8894177

alpha-Adrenoceptor and opioid receptor modulation of clonidine-induced antinociception.

PubMed

Sierralta, F; Naquira, D; Pinardi, G; Miranda, H F

1996-10-01

1. The antinociceptive action of clonidine (Clon) and the interactions with alpha 1, alpha 2 adrenoceptor and opioid receptor antagonists was evaluated in mice by use of chemical algesiometric test (acetic acid writhing test). 2. Clon produced a dose-dependent antinociceptive action and the ED50 for intracerebroventricular (i.c.v.) was lower than for intraperitoneal (i.p.) administration (1 ng kg-1 vs 300 ng kg-1). The parallelism of the dose-response curves indicates activation of a common receptor subtype. 3. Systemic administration of prazosin and terazosin displayed antinociceptive activity. Pretreatment with prazosin produced a dual action: i.c.v. Clon effect did not change, and i.p. Clon effect was enhanced. Yohimbine i.c.v. or i.p. did not induce antinonciception, but antagonized Clon-induced activity. These results suggest that alpha 1- and alpha 2-adrenoceptors, either located at the pre- and/or post-synaptic level, are involved in the control of spinal antinociception. 4. Naloxone (NX) and naltrexone (NTX) induced antinociceptive effects at low doses (microgram kg-1 range) and a lower antinociceptive effect at higher doses (mg kg-1 range). Low doses of NX or NTX antagonized Clon antinociception, possibly in relation to a preferential mu opioid receptor antagonism. In contrast, high doses of NX or NTX increased the antinociceptive activity of Clon, which could be due to an enhanced inhibition of the release of substance P. 5. The results obtained in the present work suggest the involvement of alpha 1-, alpha 2-adrenoceptor and opioid receptors in the modulation of the antinociceptive activity of clonidine, which seems to be exerted either at spinal and/or supraspinal level.

Activation of p42/p44 mitogen-activated protein kinase and contraction by prostaglandin F2alpha, ionomycin, and thapsigargin in cat iris sphincter smooth muscle: inhibition by PD98059, KN-93, and isoproterenol.

PubMed

Ansari, H R; Husain, S; Abdel-Latif, A A

2001-10-01

In the present study we investigated the cross talk between the Ca2+ mobilization pathway and the mitogen-activated protein (MAP) kinase pathway and contraction in the cat iris sphincter smooth muscle. Three Ca2+-mobilizing agonists, namely, prostaglandin F2alpha (PGF2alpha), ionomycin, and thapsigargin, and three specific inhibitors, PD98059, a p42/p44 MAP kinase inhibitor; KN-93, a Ca2+-calmodulin-dependent protein kinase II (CaMKII) blocker; and isoproterenol, a cAMP-elevating agent, were used. Changes in tension in response to the agonists were recorded isometrically and MAP kinase phosphorylation and activation were monitored by Western blotting and by in situ myelin basic protein phosphorylation, respectively. We found that 1) stimulation of the sphincter muscle with PGF2alpha, ionomycin, or thapsigargin resulted in rapid phosphorylation and activation of p42/p44 MAP kinase and contraction; and 2) treatment of the muscles with PD98059, KN-93, or isoproterenol resulted in inhibition of the Ca2+-mobilizing agonist-induced responses. The contractile responses induced by PGF2alpha, ionomycin, and thapsigargin were (mg of tension/mg of wet weight tissue) 15.2, 15.4, and 16.2, respectively; the increases in MAP kinase phosphorylation by these agonists were 228, 203, and 190%, respectively; and the increases in MAP kinase activation by the agonists were 212, 191, and 162%, respectively. The stimulatory effects of the agonists on contraction and on MAP kinase phosphorylation and activation were blocked by preincubation of the muscle with PD98059, KN-93, or isoproterenol. These data demonstrate that in the iris sphincter phosphorylation and activation of p42/p44 MAP kinases by PGF2alpha, ionomycin, or thapsigargin require intracellular Ca2+ either from extracellular sources or from internal stores, that CaMKII plays an important role in the regulation of contraction, that CaMKII acts upstream of MAP kinase to control its activation, and that the MAP kinase signaling pathway can play a significant role in mediating the cellular effects of these Ca2+-mobilizing agonists.

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

Oh, Yohan; Chung, Kwang Chul, E-mail: kchung@yonsei.ac.kr

Highlights: Black-Right-Pointing-Pointer ZNF131 directly interacts with ER{alpha}. Black-Right-Pointing-Pointer The binding affinity of ZNF131 to ER{alpha} increases upon E2 stimulation. Black-Right-Pointing-Pointer ZNF131 inhibits ER{alpha}-mediated trans-activation by suppressing its homo-dimerization. Black-Right-Pointing-Pointer ZNF131 inhibits ER{alpha}-dimerization and E2-induced breast cancer cell proliferation. Black-Right-Pointing-Pointer ZNF131 inhibits estrogen signaling by acting as an ER{alpha}-co-repressor. -- Abstract: Steroid hormone estrogen elicits various physiological functions, many of which are mediated through two structurally and functionally distinct estrogen receptors, ER{alpha} and ER{beta}. The functional role of zinc finger protein 131 (ZNF131) is poorly understood, but it is assumed to possess transcriptional regulation activity due to the presence of amore » DNA binding motif. A few recent reports, including ours, revealed that ZNF131 acts as a negative regulator of ER{alpha} and that SUMO modification potentiates the negative effect of ZNF131 on estrogen signaling. However, its molecular mechanism for ER{alpha} inhibition has not been elucidated in detail. Here, we demonstrate that ZNF131 directly interacts with ER{alpha}, which consequently inhibits ER{alpha}-mediated trans-activation by suppressing its homo-dimerization. Moreover, we show that the C-terminal region of ZNF131 containing the SUMOylation site is necessary for its inhibition of estrogen signaling. Taken together, these data suggest that ZNF131 inhibits estrogen signaling by acting as an ER{alpha}-co-repressor.« less

[Local immune and oxidative status in exacerbated chronic apical periodontitis].

PubMed

Konoplya, A I; Goldobin, D D; Loktionov, A L

The aim of the study was to define local immune and oxidative changes in patients with exacerbated chronic apical periodontitis. These changes were assessed in saliva of 67 patients with the mean age of 31±2.5 before and after treatment. The study revealed disturbances in cytokines and complement system balance and activation of lipids peroxidation. Combination of Gepon or Vobenzim with Essentiale forte H and Kaskatol proved to be the most effective for correction of this imbalance.

[Aromatase activities of endometrial carcinomas and both basic and clinical analyses of endometrial hyperplasia as a premalignant disease].

PubMed

Sasaki, H

1993-08-01

Paraffin-embedded materials obtained from 117 cases of endometrial hyperplasia and 84 cases of carcinoma were used for measurement of both ki-ras and p53 gene mutation and aromatase (ARO) and TGF-alpha immunostaining. The overall incidence of ki-ras mutations in the hyperplasia specimens (16%) was similar to the incidence detected in carcinomas (18%). None of 117 endometrial hyperplasias were found to have mutations in the p53 gene, whereas mutations were seen in 3 (13.3%) endometrial carcinomas. The intensity of both ARO and TGF-alpha immunostaining was increased in glands of both hyperplasia and carcinoma, and also in the interstitium of carcinoma. The positive sites of both ARO and TGF-alpha were almost the same, with an incidence below 40% in both hyperplasias and carcinomas. The cultured cells of endometrial carcinoma showed aromatase activity below MCF-7 cells, because testosterone was converted to estradiol (E2). TGF-alpha induced cell growth with at an optimal concentration. In HEC-59 cells, TGF-alpha increased both ARO-activity and mRNA. Some promoters on ARO-exon 1 in HEC-59 cells were different from those in BeWo cells. Progesterone inhibited the E2-induced excretion of pre TGF-alpha in endometrial carcinoma cells. These findings suggest that endometrial hyperplasia can be a premalignant condition of carcinoma, and can be initiated by both ki-ras codon 12 mutation and abnormal activity of ARO induced by TGF-alpha. In addition, HEC-59 cells may possess autocrine/paracrine properties involving ARO, E2 and TGF-alpha.

Characterisation of exacerbation risk and exacerbator phenotypes in the POET-COPD trial.

PubMed

Beeh, Kai M; Glaab, Thomas; Stowasser, Susanne; Schmidt, Hendrik; Fabbri, Leonardo M; Rabe, Klaus F; Vogelmeier, Claus F

2013-10-29

Data examining the characteristics of patients with frequent exacerbations of chronic obstructive pulmonary disease (COPD) and associated hospitalisations and mortality are scarce. Post-hoc analysis of the Prevention Of Exacerbations with Tiotropium in COPD (POET-COPD) trial, targeting exacerbations as the primary endpoint. Patients were classified as non-, infrequent, and frequent exacerbators (0, 1, or ≥ 2 exacerbations during study treatment), irrespective of study treatment. A multivariate Cox regression model assessed the effect of covariates on time to first exacerbation. In total, 7376 patients were included in the analysis: 63.5% non-exacerbators, 22.9% infrequent, 13.6% frequent exacerbators. Factors significantly associated with exacerbation risk were age, sex, body mass index, COPD duration and severity, smoking history, baseline inhaled corticosteroid use, and preceding antibiotic or systemic corticosteroid courses. Frequent exacerbators had greater severity and duration of COPD, received more pulmonary medication, and ≥ 2 systemic corticosteroid or antibiotic courses in the preceding year, and were more likely to be female and ex-smokers. The small proportion of frequent exacerbators (13.6%) accounted for 56.6% of exacerbation-related hospitalisations, which, overall, were associated with a three-fold increase in mortality. The frequent exacerbator phenotype was closely associated with exacerbation-related hospitalisations, and exacerbation-related hospitalisations were associated with poorer survival. NCT00563381; Study identifier: BI 205.389.

The alpha2-delta protein: an auxiliary subunit of voltage-dependent calcium channels as a recognized drug target.

PubMed

Thorpe, Andrew J; Offord, James

2010-07-01

Currently, there are two drugs on the market, gabapentin (Neurontin) and pregabalin (Lyrica), that are proposed to exert their therapeutic effect through binding to the alpha2-delta subunit of voltage-sensitive calcium channels. This activity was unexpected, as the alpha2-delta subunit had previously been considered not to be a pharmacological target. In this review, the role of the alpha2-delta subunits is discussed and the mechanism of action of the alpha2-delta ligands in vitro and in vivo is summarized. Finally, new insights into the mechanism of drugs that bind to this protein are discussed.

Effects of a alpha 2C-adrenoreceptor gene polymorphism on neural responses to facial expressions in depression.

PubMed

Neumeister, Alexander; Drevets, Wayne C; Belfer, Inna; Luckenbaugh, David A; Henry, Shannan; Bonne, Omer; Herscovitch, Peter; Goldman, David; Charney, Dennis S

2006-08-01

Alterations in processing of emotionally salient information have been reported in individuals with major depressive disorder (MDD). Evidence suggests a role for noradrenaline in the regulation of a cortico-limbic-striatal circuit that has also been implicated in the pathophysiology of MDD. Herein, we studied the physiological consequences of a common coding polymorphism of the gene for the alpha(2C)-adrenoreceptor (AR) subtype--the deletion of four consecutive amino acids at codons 322-325 of the alpha2C-AR (alpha2CDel322-325-AR) in medication-free, remitted individuals with MDD (rMDD), and healthy control subjects. After injection of 10 mCi of H2(15)O, positron emission tomography (PET) measures of neural activity were acquired while subjects were viewing unmasked sad, happy, and fearful faces. The neural responses to sad facial expressions were increased in the amygdala and decreased in the left ventral striatum in rMDD patients relative to healthy control subjects. Furthermore, we report that rMDD carriers of one or two copies of the alpha2CDel322-325-AR exhibit greater amygdala as well as pregenual and subgenual anterior cingulate gyrus neuronal activity in response to sad faces than healthy alpha2CDel322-325-AR carriers and rMDD noncarriers. These results suggest that the alpha2CDel322-325-AR confers a change in brain function implicating this alpha2-AR subtype into the pathophysiology of MDD.

Tumor necrosis factor receptor-1 can function through a G alpha q/11-beta-arrestin-1 signaling complex.

PubMed

Kawamata, Yuji; Imamura, Takeshi; Babendure, Jennie L; Lu, Juu-Chin; Yoshizaki, Takeshi; Olefsky, Jerrold M

2007-09-28

Tumor necrosis factor-alpha (TNFalpha) is a proinflammatory cytokine secreted from macrophages and adipocytes. It is well known that chronic TNFalpha exposure can lead to insulin resistance both in vitro and in vivo and that elevated blood levels of TNFalpha are observed in obese and/or diabetic individuals. TNFalpha has many acute biologic effects, mediated by a complex intracellular signaling pathway. In these studies we have identified new G-protein signaling components to this pathway in 3T3-L1 adipocytes. We found that beta-arrestin-1 is associated with TRAF2 (TNF receptor-associated factor 2), an adaptor protein of TNF receptors, and that TNFalpha acutely stimulates tyrosine phosphorylation of G alpha(q/11) with an increase in G alpha(q/11) activity. Small interfering RNA-mediated knockdown of beta-arrestin-1 inhibits TNFalpha-induced tyrosine phosphorylation of G alpha(q/11) by interruption of Src kinase activation. TNFalpha stimulates lipolysis in 3T3-L1 adipocytes, and beta-arrestin-1 knockdown blocks the effects of TNFalpha to stimulate ERK activation and glycerol release. TNFalpha also led to activation of JNK with increased expression of the proinflammatory gene, monocyte chemoattractant protein-1 and matrix metalloproteinase 3, and beta-arrestin-1 knockdown inhibited both of these effects. Taken together these results reveal novel elements of TNFalpha action; 1) the trimeric G-protein component G alpha(q/11) and the adapter protein beta-arrestin-1 can function as signaling molecules in the TNFalpha action cascade; 2) beta-arrestin-1 can couple TNFalpha stimulation to ERK activation and lipolysis; 3) beta-arrestin-1 and G alpha(q/11) can mediate TNFalpha-induced phosphatidylinositol 3-kinase activation and inflammatory gene expression.

Purinergic signaling is required for fluid shear stress-induced NF-{kappa}B translocation in osteoblasts

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

Genetos, Damian C., E-mail: dgenetos@ucdavis.edu; Karin, Norman J.; Geist, Derik J.

2011-04-01

Fluid shear stress regulates gene expression in osteoblasts, in part by activation of the transcription factor NF-{kappa}B. We examined whether this process was under the control of purinoceptor activation. MC3T3-E1 osteoblasts under static conditions expressed the NF-{kappa}B inhibitory protein I{kappa}B{alpha} and exhibited cytosolic localization of NF-{kappa}B. Under fluid shear stress, I{kappa}B{alpha} levels decreased, and concomitant nuclear localization of NF-{kappa}B was observed. Cells exposed to fluid shear stress in ATP-depleted medium exhibited no significant reduction in I{kappa}B{alpha}, and NF-{kappa}B remained within the cytosol. Similar results were found using oxidized ATP or Brilliant Blue G, P2X{sub 7} receptor antagonists, indicating that themore » P2X{sub 7} receptor is responsible for fluid shear-stress-induced I{kappa}B{alpha} degradation and nuclear accumulation of NF-{kappa}B. Pharmacologic blockage of the P2Y6 receptor also prevented shear-induced I{kappa}B{alpha} degradation. These phenomena involved neither ERK1/2 signaling nor autocrine activation by P2X{sub 7}-generated lysophosphatidic acid. Our results suggest that fluid shear stress regulates NF-{kappa}B activity through the P2Y{sub 6} and P2X{sub 7} receptor.« less

Neuronal Antibody Biomarkers for Sydenham’s Chorea Identify a New Group of Children with Chronic Recurrent Episodic Acute Exacerbations of Tic and Obsessive Compulsive Symptoms Following a Streptococcal Infection

PubMed Central

Singer, Harvey S.; Mascaro-Blanco, Adda; Alvarez, Kathy; Morris-Berry, Christina; Kawikova, Ivana; Ben-Pazi, Hilla; Thompson, Carol B.; Ali, Syed F.; Kaplan, Edward L.; Cunningham, Madeleine W.

2015-01-01

Several autoantibodies (anti-dopamine 1 (D1R) and 2 (D2R) receptors, anti-tubulin, anti-lysoganglioside-GM1) and antibody-mediated activation of calcium calmodulin dependent protein kinase II (CaMKII) signaling activity are elevated in children with Sydenham’s chorea (SC). Recognizing proposed clinical and autoimmune similarities between SC and PANDAS (pediatric autoimmune neuropsychiatric disorder associated with a streptococcal infection), we sought to identify serial biomarker changes in a slightly different population. Antineuronal antibodies were measured in eight children (mean 11.3 years) with chronic, dramatic, recurrent tics and obsessive-compulsive disorder (OCD) associated with a group A β-hemolytic streptococcal (GABHS) respiratory tract infection, but differing because they lacked choreiform movements. Longitudinal serum samples in most subjects included two pre-exacerbation samples, Exac), one midst Exac (abrupt recurrence of tic/OCD; temporally association with a GABHS infection in six of eight subjects), and two post-Exac. Controls included four groups of unaffected children (n = 70; mean 10.8 years) obtained at four different institutions and published controls. Clinical exacerbations were not associated with a significant rise in antineuronal antibody titers. CaMKII activation was increased at the GABHS exacerbation point in 5/6 subjects, exceeded combined and published control’s 95th percentile at least once in 7/8 subjects, and median values were elevated at each time point. Anti-tubulin and anti-D2R titers did not differ from published or combined control group’s 95th percentile or median values. Differences in anti-lysoganglioside-GM1 and anti-D1R titers were dependent on the selected control. Variances in antibody titers and CaMKII activation were identified among the institutional control groups. Based on comparisons to published studies, results identify two groups of PANDAS: 1) a cohort, represented by this study, which lacks choreiform movements and elevated antibodies against D2R; 2) the originally reported group with choreiform movements and elevated anti-D2R antibodies, similar to SC. Increased antibody mediated CaMKII activation was found in both groups and requires further study as a potential biomarker. PMID:25793715

Structure and kinetic investigation of Streptococcus pyogenes family GH38 alpha-mannosidase.

PubMed

Suits, Michael D L; Zhu, Yanping; Taylor, Edward J; Walton, Julia; Zechel, David L; Gilbert, Harry J; Davies, Gideon J

2010-02-03

The enzymatic hydrolysis of alpha-mannosides is catalyzed by glycoside hydrolases (GH), termed alpha-mannosidases. These enzymes are found in different GH sequence-based families. Considerable research has probed the role of higher eukaryotic "GH38" alpha-mannosides that play a key role in the modification and diversification of hybrid N-glycans; processes with strong cellular links to cancer and autoimmune disease. The most extensively studied of these enzymes is the Drosophila GH38 alpha-mannosidase II, which has been shown to be a retaining alpha-mannosidase that targets both alpha-1,3 and alpha-1,6 mannosyl linkages, an activity that enables the enzyme to process GlcNAc(Man)(5)(GlcNAc)(2) hybrid N-glycans to GlcNAc(Man)(3)(GlcNAc)(2). Far less well understood is the observation that many bacterial species, predominantly but not exclusively pathogens and symbionts, also possess putative GH38 alpha-mannosidases whose activity and specificity is unknown. Here we show that the Streptococcus pyogenes (M1 GAS SF370) GH38 enzyme (Spy1604; hereafter SpGH38) is an alpha-mannosidase with specificity for alpha-1,3 mannosidic linkages. The 3D X-ray structure of SpGH38, obtained in native form at 1.9 A resolution and in complex with the inhibitor swainsonine (K(i) 18 microM) at 2.6 A, reveals a canonical GH38 five-domain structure in which the catalytic "-1" subsite shows high similarity with the Drosophila enzyme, including the catalytic Zn(2+) ion. In contrast, the "leaving group" subsites of SpGH38 display considerable differences to the higher eukaryotic GH38s; features that contribute to their apparent specificity. Although the in vivo function of this streptococcal GH38 alpha-mannosidase remains unknown, it is shown to be an alpha-mannosidase active on N-glycans. SpGH38 lies on an operon that also contains the GH84 hexosaminidase (Spy1600) and an additional putative glycosidase. The activity of SpGH38, together with its genomic context, strongly hints at a function in the degradation of host N- or possibly O-glycans. The absence of any classical signal peptide further suggests that SpGH38 may be intracellular, perhaps functioning in the subsequent degradation of extracellular host glycans following their initial digestion by secreted glycosidases.

Validation of the Hong Kong Chinese version of the St. George Respiratory Questionnaire in patients with bronchiectasis.

PubMed

Chan, Shelley L; Chan-Yeung, Moira M; Ooi, Gaik C; Lam, Cindy L; Cheung, Tung F; Lam, Wah K; Tsang, Kenneth W

2002-12-01

To validate the Hong Kong Chinese version of the St. George Respiratory Questionnaire (SGRQ-HK) in patients with bronchiectasis. Outpatients (93 patients; 61 women; mean age [+/- SD], 59.0 +/- 14.2 years) were assessed at baseline by the SGRQ-HK, the Hong Kong Chinese version of the 36-item short form health survey (SF-36-HK), and the hospital anxiety and depression scale (HADS). Forty randomly selected patients also were reassessed at 2 weeks for repeatability. Seventy-two patients were further reassessed at 6 months for responsiveness. Cronbach alpha coefficients, which reflected internal consistency, were > 0.7 for all SGRQ-HK components except for symptoms (alpha = 0.59), and the intraclass correlation coefficients between baseline and the 2-week follow-up visits were between 0.80 and 0.94 (p > 0.05). SGRQ-HK component scores and total scores correlated with all the component scores of the SF-36-HK and the HADS (p < 0.02). SGRQ-HK component scores and total scores correlated with the scores of the SF-36-HK and the HADS, confirming the concurrent validity. All SGRQ-HK scores correlated negatively with FEV(1), FVC, and arterial oxygen saturation (p < 0.005), while the activity score correlated with the Karnofsky performance scale and the number of bronchiectatic lobes (p < 0.001). SGRQ-HK scores positively correlated with Borg scale scores, exacerbation frequency, and 24-h sputum volumes (p < 0.03). Patients with 24-h sputum volumes of > or = 10 mL or < 10 mL had significantly different SQRG-HK component scores and total scores (p < 0.002), although this sensitivity was not displayed by scores on the HADS or the SF-36-HK. Patients with 25% reductions in 24-h sputum volumes had significant improvements in SGRQ-HK activity scores, impact scores, and total scores (p < 0.02), but not in other quality-of-life measures or clinical parameters, indicating the responsiveness of the SGRQ-HK. The SGRQ-HK is a valid and sensitive instrument for determining quality of life in bronchiectasis patients.

Overexpression of protein kinase FA/GSK-3 alpha (a proline-directed protein kinase) correlates with human hepatoma dedifferentiation/progression.

PubMed

Yang, S D; Yu, J S; Yang, C C; Lee, S C; Lee, T T; Ni, M H; Kuan, C Y; Chen, H C

1996-05-01

Computer analysis of protein phosphorylation sites sequence revealed that transcriptional factors and viral oncoproteins are prime targets for regulation of proline-directed protein phosphorylation, suggesting an association of the proline-directed protein kinase (PDPK) family with neoplastic transformation and tumorigenesis. In this report, an immunoprecipitate activity assay of protein kinase FA/glycogen synthase kinase-3 alpha (kinase F(A)/GSK-3 alpha) (a member of PDPK family) has been optimized for human hepatoma and used to demonstrate for the first time significantly increased (P < 0.01) activity in poorly differentiated SK-Hep-1 hepatoma (24.2 +/- 2.8 units/mg) and moderately differentiated Mahlavu hepatoma (14.5 +/- 2.2 units/mg) when compared to well differentiated Hep 3B hepatoma (8.0 +/- 2.4 units/mg). Immunoblotting analysis revealed that increased activity of kinase FA/GSK-3 alpha is due to overexpression of the protein. Elevated kinase FA/GSK-3 alpha expression in human hepatoma biopsies relative to normal liver tissue was found to be even more profound. This kinase appeared to be fivefold overexpressed in well differentiated hepatoma and 13-fold overexpressed in poorly differentiated hepatoma when compared to normal liver tissue. Taken together, the results provide initial evidence that overexpression of kinase FA/GSK-3 alpha is involved in human hepatoma dedifferentiation/progression. Since kinase FA/GSK-3 alpha is a PDPK, the results further support a potential role of this kinase in human liver tumorigenesis, especially in its dedifferentiation/progression.

Regulation of Ca(2+)/calmodulin-dependent protein kinase kinase alpha by cAMP-dependent protein kinase: I. Biochemical analysis.

PubMed

Okuno, S; Kitani, T; Fujisawa, H

2001-10-01

Ca(2+)/calmodulin-dependent protein kinases (CaM-kinases) I and IV are activated upon phosphorylation of their Thr(177) and Thr(196), respectively, by the upstream Ca(2+)/calmodulin-dependent protein kinases CaM-kinase kinase alpha and beta, and deactivated upon dephosphorylation by protein phosphatases such as CaM-kinase phosphatase. Recent studies demonstrated that the activity of CaM-kinase kinase alpha is decreased upon phosphorylation by cAMP-dependent protein kinase (PKA), and the relationship between the inhibition and phosphorylation of CaM-kinase kinase alpha by PKA has been studied. In the present study, we demonstrate that the activity of CaM-kinase kinase alpha toward PKIV peptide, which contains the sequence surrounding Thr(196) of CaM-kinase IV, is increased by incubation with PKA in the presence of Ca(2+)/calmodulin but decreased in its absence, while the activity toward CaM-kinase IV is decreased by incubation with PKA in both the presence and absence of Ca(2+)/calmodulin. Six phosphorylation sites on CaM-kinase kinase alpha, Ser(24) for autophosphorylation, and Ser(52), Ser(74), Thr(108), Ser(458), and Ser(475) for phosphorylation by PKA, were identified by amino acid sequence analysis of the phosphopeptides purified from the tryptic digest of the phosphorylated enzymes. The presence of Ca(2+)/calmodulin suppresses phosphorylation on Ser(52), Ser(74), Thr(108), and Ser(458) by PKA, but accelerates phosphorylation on Ser(475). The changes in the activity of the enzyme upon phosphorylation appear to occur as a result of conformational changes induced by phosphorylation on several sites.

A cross-linking study of the Ca2+, Mg2+-activated adenosine triphosphatase of Escherichia coli.

PubMed

Bragg, P D; Hou, C

1980-05-01

The solubilized Ca2+,Mg2+-activated adenosine triphosphatase of Escherichia coli is composed of five subunits designated alpha, beta, gamma, delta and epsilon in order of decreasing molecular weight. The subunit structure of the enzyme has been investigated by the use of the cleavable cross-linking agents dithiobis(succinimidyl propionate), methyl-4-mercaptobutyrimidate, dimethyl-3,3'-dithiobispropionimidate, disuccinimidyl tartarate, and cupric 1,10-phenanthrolinate. The products of cross-linking were analyzed by two different two-dimensional gel electrophoresis systems. The following cross-linked subunit dimers were observed: alpha 2, beta 2, alpha beta, alpha delta, beta gamma, beta delta, beta epsilon and gamma epsilon. These results, together with other published data, are discussed in relation to a model of the arrangement of the subunits in the ATPase molecule.

[Predictive factors associated with severity of asthma exacerbations].

PubMed

Atiş, Sibel; Kaplan, Eylem Sercan; Ozge, Cengiz; Bayindir, Suzan

2008-01-01

Several factors have been accused for asthma exacerbations, however, very few studies have evaluated whether different factors predict severity of asthma exacerbation. We aimed to determine the predictive factors for severity of asthma exacerbation. Retrospective analysis of data on 93 patients visited our emergency-department because of asthma exacerbation was reviewed. Hospitalization in intensive care unit and/or intubation because of asthma was accepted as the criteria for severe exacerbation. Logistic regression analysis estimated the strength of association of each variable, potentially related to severe asthmatic exacerbation, with severe/very severe as compared to mild/moderate asthmatic exacerbation. Independent variables included in the analysis were age, sex, smoking history, inhaler steroid using, compliance with medication, chronic asthma severity, presence of additional atopic diseases, prick test positivity, provocative factors, number of short-acting beta(2)-agonist using, number of visits to emergency department for asthma over one year period, previous severe exacerbation, pulmonary functions, and blood eosinophil count. 20 were severe/very severe and 73 mild/moderate asthmatic exacerbation. Frequent using of short-acting beta(2)-agonist (OR= 1.5, 95% CI= 1.08-5.3, p= 0.003), noncompliance with medication (OR= 3.6, 95% CI= 1.3-9.9, p= 0.013), previous severe asthmatic exacerbation (OR= 3.8, 95% CI= 1.48-10.01, p= 0.005) and recent admission to hospital (OR= 2.9, 95% CI= 1.07-8.09, p= 0.037) were found to be predictive factors for severe asthmatic exacerbation. Different predictive factors, in particular frequent using of short-acting beta(2)-agonist and noncompliance with medication may be associated with severe asthma exacerbations compared to milder exacerbations. This suggests different mechanisms are responsible for severity of asthma exacerbation.

A defective retroviral vector encoding human interferon-alpha2 can transduce human leukemic cell lines.

PubMed

Austruy, E; Bagnis, C; Carbuccia, N; Maroc, C; Birg, F; Dubreuil, P; Mannoni, P; Chabannon, C

1998-01-01

Using the LXSN backbone, a defective retroviral vector (LISN) was constructed that encodes the human interferon (IFN)-alpha2 (hIFN-alpha2) gene and the neomycin resistance gene; the hIFN-alpha2 gene was cloned from human placental genomic DNA. High titers of the LISN retrovirus were produced by the amphotropic packaging cell line GP+envAM12. LISN is able to infect three human hematopoietic and leukemic cell lines: K562, LAMA-84, and TF-1. G418-resistant cells were detected in a similar proportion after infection with either the LISN retroviral vector or the LnLSN retroviral vector (encoding the nlsLacZ gene instead of hIFN-alpha2), suggesting that hIFN-alpha2 does not inhibit (or only partially inhibits) the production of retroviral particles by the packaging cell line and the infection of human cells. LISN-infected cells express and secrete hIFN-alpha2 as demonstrated by Northern blot analysis of poly(A)+ RNA, detection of the intracellular protein by fluorescence-activated cell sorter analysis, and detection of secreted hIFN-alpha in cell supernatants using an enzyme-linked immunosorbent assay. Retrovirally produced hIFN-alpha2 is biologically active, as demonstrated by the partial inhibition of the growth of K562 and TF-1, the modulation of the expression of cell surface antigens, the induction of the (2'-5') oligoadenylate synthetase, and, for LAMA-84, the down-modulation of the BCR-ABL protein. We conclude that the infection of human leukemic cell lines with a retroviral vector encoding hIFN-alpha2 is feasible and induces the expected biological effects. This experimental model will be useful in investigating the possibility of transducing normal and leukemic cells and hematopoietic progenitors and in determining the consequences of the autocrine production of hIFN-alpha2 on the behavior of these cells.

Antitumor properties of (5E,7E) analogs of vitamin D3.

PubMed

Filip, B; Milczarek, M; Wietrzyk, J; Chodyński, M; Kutner, A

2010-07-01

Geometric isomers (5E,7E) of major active metabolites of vitamin D3 [1alpha,25(OH)2D3 and (24R)-1,24(OH)2D3] were synthesized by a new convenient procedure. Vitamin D triene system of the metabolites was first derivatized as a Diels-Alder adduct. Removal of the triene protecting group, in a key synthetic step, yielded the title compounds PRI-2208 and PRI-2209, respectively. The analogs were examined for their antiproliferative activity in vitro against human breast cancer cells (MCF-7) and promyelocytic leukemia (HL-60) cells. The activity was compared with one of the parent compounds. Both analogs examined revealed similar or higher antiproliferative activity compared to 1alpha,25(OH)2D3 or to (24R)-1,24(OH)2D3. The studies of calcemic activity in vivo showed that analogs PRI-2208 and PRI-2209 did not influence the serum calcium level in doses, in which 1alpha,25(OH)2D3 or (24R)-1,24(OH)2D3 significantly increased this level. The antitumor activity of these analogs in the LLC mice tumor model was studied. Analog PRI-2208 was found to be more active in inhibiting LLC tumor growth than 1alpha,25(OH)2D3, as well as than PRI-2191 and PRI-2209. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Alpha-galactosidase versus active charcoal for improving sonographic visualization of abdominal organs in patients with excessive intestinal gas

PubMed Central

Maconi, G.; Bolzacchini, E.; Radice, E.; Marzocchi, M.; Badini, M.

2012-01-01

Background and aims Intestinal gas is a frequent cause of poor visualization during gastrointestinal ultrasound (US). The enzyme alpha-galactosidase may reduce intestinal gas production, thereby improving abdominal US visualization. We compared the efficacies of alpha-galactosidase and active charcoal in improving US visualization in patients with previous unsatisfactory abdominal US scans caused by excessive intestinal gas. Materials and methods: 45 patients with poor visualization of at least one target organ: pancreas, hepatic lobes (score 0–2) or common bile duct (CBD) (score 0–1) were enrolled in a prospective randomized, crossover, observer-blinded study. The patients received alpha-galactosidase (Sinaire Forte, Promefarm, Milan, Italy) 600 GalU t.i.d. for 2 days before abdominal US plus 900 GalU the morning of exam or active charcoal 448 mg t.i.d., for 2 days before the exam plus 672 mg the morning of the exam. Visualization was graded as follows: 0 = none (complete gas interference); 1 = severe interference, 2 = moderate interference, 3 = mild interference; 4 = complete (no gas interference). Results: 42 patients completed the study. Both alpha-galactosidase and active charcoal improved the visualization of target organs. Visualization of the right hepatic lobe, CBD and pancreatic tail was significantly improved (vs. baseline) only by alpha-galactosidase (p < 0.01). Scores ≥3 for all parts of the pancreas and both hepatic lobes were achieved in only 12.5% of the patients after both treatments. Both products were well tolerated. Conclusion: Alpha-galactosidase and active charcoal can improve US visualization of abdominal organs in patients whose scans are frequently unsatisfactory due to excessive intestinal gas. Visualization of the pancreatic tail and right hepatic lobe was significantly improved only by alpha-galactosidase. However, both treatments allowed adequate visualization of all target organs during the same examination only in a few patients. PMID:23730387

Endosulfan induces CYP2B6 and CYP3A4 by activating the pregnane X receptor

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

Casabar, Richard C.T.; Das, Parikshit C.; DeKrey, Gregory K.

Endosulfan is an organochlorine pesticide commonly used in agriculture. Endosulfan has affects on vertebrate xenobiotic metabolism pathways that may be mediated, in part, by its ability to activate the pregnane X receptor (PXR) and/or the constitutive androstane receptor (CAR) which can elevate expression of cytochrome P450 (CYP) enzymes. This study examined the dose-dependency and receptor specificity of CYP induction in vitro and in vivo. The HepG2 cell line was transiently transfected with CYP2B6- and CYP3A4-luciferase promoter reporter plasmids along with human PXR (hPXR) or hCAR expression vectors. In the presence of hPXR, endosulfan-alpha exposure caused significant induction of CYP2B6 (16-fold)more » and CYP3A4 (11-fold) promoter activities over control at 10 {mu}M. The metabolite endosulfan sulfate also induced CYP2B6 (12-fold) and CYP3A4 (6-fold) promoter activities over control at 10 {mu}M. In the presence of hCAR-3, endosulfan-alpha induced CYP2B6 (2-fold) promoter activity at 10 {mu}M, but not at lower concentrations. These data indicate that endosulfan-alpha significantly activates hPXR strongly and hCAR weakly. Using western blot analysis of human hepatocytes, the lowest concentrations at which CYP2B6 and CYP3A4 protein levels were found to be significantly elevated by endosulfan-alpha were 1.0 {mu}M and 10 {mu}M, respectively. In mPXR-null/hPXR-transgenic mice, endosulfan-alpha exposure (2.5 mg/kg/day) caused a significant reduction of tribromoethanol-induced sleep times by approximately 50%, whereas no significant change in sleep times was observed in PXR-null mice. These data support the role of endosulfan-alpha as a strong activator of PXR and inducer of CYP2B6 and CYP3A4, which may impact metabolism of CYP2B6 or CYP3A4 substrates.« less

Endosulfan induces CYP2B6 and CYP3A4 by activating the pregnane X receptor.

PubMed

Casabar, Richard C T; Das, Parikshit C; Dekrey, Gregory K; Gardiner, Catherine S; Cao, Yan; Rose, Randy L; Wallace, Andrew D

2010-06-15

Endosulfan is an organochlorine pesticide commonly used in agriculture. Endosulfan has affects on vertebrate xenobiotic metabolism pathways that may be mediated, in part, by its ability to activate the pregnane X receptor (PXR) and/or the constitutive androstane receptor (CAR) which can elevate expression of cytochrome P450 (CYP) enzymes. This study examined the dose-dependency and receptor specificity of CYP induction in vitro and in vivo. The HepG2 cell line was transiently transfected with CYP2B6- and CYP3A4-luciferase promoter reporter plasmids along with human PXR (hPXR) or hCAR expression vectors. In the presence of hPXR, endosulfan-alpha exposure caused significant induction of CYP2B6 (16-fold) and CYP3A4 (11-fold) promoter activities over control at 10 microM. The metabolite endosulfan sulfate also induced CYP2B6 (12-fold) and CYP3A4 (6-fold) promoter activities over control at 10 microM. In the presence of hCAR-3, endosulfan-alpha induced CYP2B6 (2-fold) promoter activity at 10 microM, but not at lower concentrations. These data indicate that endosulfan-alpha significantly activates hPXR strongly and hCAR weakly. Using western blot analysis of human hepatocytes, the lowest concentrations at which CYP2B6 and CYP3A4 protein levels were found to be significantly elevated by endosulfan-alpha were 1.0 microM and 10 microM, respectively. In mPXR-null/hPXR-transgenic mice, endosulfan-alpha exposure (2.5mg/kg/day) caused a significant reduction of tribromoethanol-induced sleep times by approximately 50%, whereas no significant change in sleep times was observed in PXR-null mice. These data support the role of endosulfan-alpha as a strong activator of PXR and inducer of CYP2B6 and CYP3A4, which may impact metabolism of CYP2B6 or CYP3A4 substrates. Copyright 2010 Elsevier Inc. All rights reserved.

G protein abnormalities in pituitary adenomas.

PubMed

Spada, A; Lania, A; Ballarè, E

1998-07-25

It has been demonstrated that the majority of secreting and nonsecreting adenomas is monoclonal in origin suggesting that these neoplasia arise from the replication of a single mutated cell, in which growth advantage results from either activation of protooncogenes or inactivation of antioncogenes. Although a large number of genes has been screened for mutations, only few genetic abnormalities have been found in pituitary tumors such as allelic deletion of chromosome 11q13 where the MEN-1 gene has been localised, and mutations in the gene encoding the alpha subunit of the stimulatory Gs and Gi2 protein. These mutations constitutively activate the alpha subunit of the Gs and Gi2 protein by inhibiting their intrinsic GTPase activity. Both Gs alpha and Gi2alpha can be considered products of protooncogenes (gsp and gip2, respectively) since gain of function mutations that activate mitogenic signals have been recognized in human tumors. Gsp oncogene is found in 30-40% of GH-secreting adenomas, in a low percentage of nonfunctioning and ACTH-secreting pituitary adenomas, in toxic thyroid adenomas and differentiated thyroid carcinomas. The same mutations, occurred early in embriogenesis, have been also identified in tissues from patients affected with the McCune Albright syndrome. These mutations result in an increased cAMP production and in the subsequent overactivation of specific pathways involved in both cell growth and specific programmes of cell differentiation. By consequence, the endocrine tumors expressing gsp oncogene retain differentiated functions. The gip2 oncogene has been identified in about 10% of nonfunctioning pituitary adenomas, in tumors of the ovary and the adrenal cortex. However, it remains to be established whether Gi proteins activate mitogenic signals in pituitary cells. Since Gi proteins are involved in mediating the effect of inhibitory neurohormones on intracellular effectors, it has been proposed that in pituitary tumors the low expression of these proteins, particularly Gi1-3alpha, may contribute to uncontrolled pituitary cells growth by preventing the transduction of inhibitory signals. While by in vitro mutagenesis it has been demonstrated that activated mutant of Gq alpha, G12alpha, G13alpha and Gz alpha are fully oncogenic, it remains to be proved whether or not these abnormalities might naturally occur in human tumors and, in particular, in pituitary adenomas.

Role of Vitamin D in reducing number of acute exacerbations in Chronic Obstructive Pulmonary Disease (COPD) patients.

PubMed

Khan, Dur Muhammad; Ullah, Aziz; Randhawa, Fawad Ahmad; Iqtadar, Somia; Butt, Nasir Farooq; Waheed, Khadija

2017-01-01

Chronic obstructive pulmonary disease (COPD) is characterized by chronic incompletely reversible poor airflow and air trapping and usually this debilitating disorder limits the outside activities of the patients depriving them of sunlight which is a rich source of Vitamin D. The objective of this study was to determine the effect of vitamin D supplementation in reducing number of acute exacerbation in COPD patients. This randomized control trial was conducted at East Medical Ward Mayo Hospital Lahore from January to December 2015 as exacerbations of COPD are season dependent. Diagnosis was confirmed by performing Pulmonary Function Tests (PFTs). Basic demographical information was obtained and baseline PFTs of the patient was done. Only Group A patients was treated with oral vitamin D intake of 2000 IU daily for 6 months. Vitamin D level was measured at 0, 2, 4, and 6 months and exacerbation of COPD, FEV1 and FVC was measured weekly. Both the groups were given standard treatment for exacerbation of COPD. Spirometry was repeated at each visit. Blood samples were collected every 2 months for vitamin D. Supplementation was stopped if vitamin D level exceeded 100ng/ml. The mean age of the patients was 46.28±8.83 years, the male to female ratio was 1.8:1. The mean 25(OH) level at baseline was 24.08±2.58 and at 6th month was 29.60±8.74. The mean FVC at baseline was 77.83±5.49 and at 6th month was 91.34±5.52. The exacerbation at baseline was present in all 120(100%) patients and at 6th month was reduced to 4(3.3%). Vitamin D supplementation has significant effect in reducing number of acute exacerbation in COPD patients when it is given for prolonged period.

Self absorption of alpha and beta particles in a fiberglass filter.

PubMed

Luetzelschwab, J W; Storey, C; Zraly, K; Dussinger, D

2000-10-01

Environmental air sampling uses fiberglass filters to collect particulate matter from the air and then a gas flow detector to measure the alpha and beta activity on the filter. When counted, the filter is located close to the detector so the alpha and beta particles emerging from the filter travel toward the detector at angles ranging from zero to nearly 90 degrees to the normal to the filter surface. The particles at small angles can readily pass through the filter, but particles at large angles pass through a significant amount of filter material and can be totally absorbed. As a result, counting losses can be great. For 4 MeV alpha particles, the filter used in this experiment absorbs 43% of the alpha particles; for 7.5 MeV alphas, the absorption is 13%. The measured beta activities also can have significant counting losses. Beta particles with maximum energies of 0.2 and 2.0 MeV have absorptions of 44 and 2%, respectively.

Pharmacological characterization of hydrolysis-resistant analogs of oleoylethanolamide with potent anorexiant properties.

PubMed

Astarita, Giuseppe; Di Giacomo, Barbara; Gaetani, Silvana; Oveisi, Fariba; Compton, Timothy R; Rivara, Silvia; Tarzia, Giorgio; Mor, Marco; Piomelli, Daniele

2006-08-01

Oleoylethanolamide (OEA) is an endogenous lipid mediator that reduces food intake, promotes lipolysis, and decreases body weight gain in rodents by activating peroxisome proliferator-activated receptor-alpha (PPAR-alpha). The biological effects of OEA are terminated by two intracellular lipid hydrolase enzymes, fatty-acid amide hydrolase and N-acylethanolamine-hydrolyzing acid amidase. In the present study, we describe OEA analogs that resist enzymatic hydrolysis, activate PPAR-alpha with high potency in vitro, and persistently reduce feeding when administered in vivo either parenterally or orally. The most potent of these compounds, (Z)-(R)-9-octadecenamide,N-(2-hydroxyethyl,1-methyl) (KDS-5104), stimulates transcriptional activity of PPAR-alpha with a half-maximal effective concentration (EC50) of 100 +/- 21 nM (n = 11). Parenteral administration of KDS-5104 in rats produces persistent dose-dependent prolongation of feeding latency and postmeal interval (half-maximal effective dose, ED50 = 2.4 +/- 1.8 mg kg(-1) i.p.; n = 18), as well as increased and protracted tissue exposure compared with OEA. Oral administration of the compound also results in a significant tissue exposure and reduction of food intake in free-feeding rats. These results suggest that the endogenous high-affinity PPAR-alpha agonist OEA may provide a scaffold for the discovery of novel orally active PPAR-alpha ligands.

CXCR4 and SDF1 expression in human meningiomas: a proliferative role in tumoral meningothelial cells in vitro.

PubMed

Bajetto, Adriana; Barbieri, Federica; Pattarozzi, Alessandra; Dorcaratto, Alessandra; Porcile, Carola; Ravetti, Jean Louis; Zona, Gianluigi; Spaziante, Renato; Schettini, Gennaro; Florio, Tullio

2007-01-01

Chemokines participate in cellular processes associated with tumor proliferation, migration, and angiogenesis. We previously demonstrated that stromal cell-derived factor 1 (SDF1) exerts a mitogenic activity in glioblastomas through the activation of its receptor CXCR4. Here we studied the expression of this chemokine in human meningiomas and its possible role in cell proliferation. Reverse transcriptase-PCR analysis for CXCR4 and SDF1 was performed on 55 human meningiomas (47 WHO grade I, 5 WHO II, and 3 WHO III). Immunolabeling for CXCR4 and SDF1 was performed on paraffin-embedded sections of these tumors. [(3)H]Thymidine uptake and Western blot analyses were performed on primary meningeal cell cultures of tumors to evaluate the proliferative activity of human SDF1alpha (hSDF1alpha) in vitro and the involvement of extracellular signal-regulated kinase 1/2 (ERK1/2) activation in this process. CXCR4 mRNA was expressed by 78% of the tumor specimens and SDF1 mRNA by 53%. CXCR4 and SDF1 were often detected in the same tumor tissues and colocalized with epithelial membrane antigen immunostaining. In 9 of 12 primary cultures from meningiomas, hSDF1alpha induced significant cell proliferation that was strongly reduced by the mitogen-activated protein kinase kinase inhibitor PD98059, involving ERK1/2 activation in the proliferative signal of hSDF1alpha. In fact, CXCR4 stimulation led to ERK1/2 phosphorylation/activation. In addition, the hSDF1alpha-induced cell proliferation was significantly correlated with the MIB1 staining index in the corresponding surgical specimen. In conclusion, we found that human meningiomas express CXCR4 and SDF1 and that hSDF1alpha induces proliferation in primary meningioma cell cultures through the activation of ERK1/2.

Identification of an antagonist that selectively blocks the activity of prostamides (prostaglandin-ethanolamides) in the feline iris.

PubMed

Woodward, D F; Krauss, A H; Wang, J W; Protzman, C E; Nieves, A L; Liang, Y; Donde, Y; Burk, R M; Landsverk, K; Struble, C

2007-02-01

The prostamides (prostaglandin-ethanolamides) and prostaglandin (PG) glyceryl esters are biosynthesized by COX-2 from the respective endocannabinoids anandamide and 2-arachidonyl glycerol. Agonist studies suggest that their pharmacologies are unique and unrelated to prostanoid receptors. This concept was further investigated using antagonists. The isolated feline iris was used as a key preparation, where prostanoid FP receptors and prostamide activity co-exist. Activity at human recombinant FP and other prostanoid receptors was determined using stable transfectants. In the feline iris, AGN 204396 produced a rightward shift of the dose-response curves for prostamide F2alpha and the prostamide F2alpha analog bimatoprost but did not block the effects of PGF2alpha and synthetic FP receptor agonists. Studies on human recombinant prostanoid receptors confirmed that AGN 204396 did not behave as a prostanoid FP receptor antagonist. AGN 204396 exhibited no antagonism at DP and EP1-4, but was a highly effective TP receptor antagonist. Contrary to expectation, the FP receptor antagonist AL-8810 efficaciously contracted the cat iris. AGN 204396 did not affect AL-8810 induced contractions, demonstrating that AL-8810 and AGN 204396 are pharmacologically distinct. Unlike AL-8810, the ethylamide derivate of AL-8810 was not an agonist. Al-8810 did not block prostamide F2alpha activity. Finally, AGN 204396 did not block PGE2-glyceryl ester activity. The ability of AGN 204396 to selectively block prostamide responses suggests the existence of prostamide sensitive receptors as entities distinct from receptors recognizing PGF2alpha and PGE2-glyceryl ester.

The Val192Leu mutation in the alpha-subunit of beta-hexosaminidase A is not associated with the B1-variant form of Tay-Sachs disease.

PubMed Central

Hou, Y.; Vavougios, G.; Hinek, A.; Wu, K. K.; Hechtman, P.; Kaplan, F.; Mahuran, D. J.

1996-01-01

Substitution mutations adversely affecting the alpha-subunit of beta-hexosaminidase A (alphabeta) (EC 3.2.1.52) result in Tay-Sachs disease. The majority affect the initial folding of the pro-alpha chain in the endoplasmic reticulum, resulting in its retention and degradation. A much less common occurrence is a mutation that specifically affects an "active-site" residue necessary for substrate binding and/or catalysis. In this case, hexosaminidase A is present in the lysosome, but it lacks all alpha-specific activity. This biochemical phenotype is referred to as the "B1-variant form" of Tay-Sachs disease. Kinetic analysis of suspected B1-variant mutations is complex because hexosaminidase A is heterodimeric and both subunits possess similar active sites. In this report, we examine a previously identified B1-variant mutation, alpha-Val192Leu. Chinese hamster ovary cells were permanently cotransfected with an alpha-cDNA-construct encoding the substitution and a mutant beta-cDNA (beta-Arg211Lys), encoding a beta-subunit that is inactive but normal in all other respects. We were surprised to find that the Val192Leu substitution, produced a pro-alpha chain that did not form alpha-beta dimers and was not transported to the lysosome. Finally, we reexamined the hexosaminidase activity and protein levels in the fibroblasts from the original patient. These data were also not consistent with the biochemical phenotype of the B1 variant of Tay-Sachs disease previously reported to be present. Thus, we conclude that the Val192Leu substitution does not specifically affect the alpha-active site. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:8659543

Biosynthesis of o-succinylbenzoic acid in Bacillus subtilis: identification of menD mutants and evidence against the involvement of the alpha-ketoglutarate dehydrogenase complex.

PubMed Central

Palaniappan, C; Taber, H; Meganathan, R

1994-01-01

The biosynthesis of o-succinylbenzoic acid (OSB), the first aromatic intermediate involved in the biosynthesis of menaquinone (vitamin K2) is demonstrated for the first time in the gram-positive bacterium Bacillus subtilis. Cell extracts were found to contain isochorismate synthase, 2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylic acid (SHCHC) synthase-alpha-ketoglutarate decarboxylase and o-succinylbenzoic acid synthase activities. An odhA mutant which lacks the decarboxylase component (usually termed E1, EC 1.2.4.2, oxoglutarate dehydrogenase [lipoamide]) of the alpha-ketoglutarate dehydrogenase complex was found to synthesize SHCHC and form succinic semialdehyde-thiamine pyrophosphate. Thus, the presence of an alternate alpha-ketoglutarate decarboxylase activity specifically involved in menaquinone biosynthesis is established for B. subtilis. A number of OSB-requiring mutants were also assayed for the presence of the various enzymes involved in the biosynthesis of OSB. All mutants were found to lack only the SHCHC synthase activity. PMID:8169214

Identification of hydrogen peroxide oxidation sites of alpha A- and alpha B-crystallins.

PubMed

Smith, J B; Jiang, X; Abraham, E C

1997-02-01

The alpha-crystallins are the most abundant structural proteins of the lens and, because of their chaperone activity, contribute to the solubility of the other crystallins. With aging, the lens crystallins undergo a variety of modifications which correlate with a loss of solubility and the development of cataract. A recent study demonstrating that alpha-crystallins exposed in vitro to FeCl3 and H2O2 exhibit decreased chaperone activity, implicates metal catalyzed oxidations of alpha-crystallins in this loss of solubility. The present study has determined that alpha-crystallins incubated with FeCl3 and H2O2 are modified by the nearly complete oxidation of all methionine residues to methionine sulfoxide, with no other detectable reaction products. The modifications were identified from the molecular weights of peptides formed by enzymatic digestion of the alpha-crystallins and located by tandem mass spectrometric analysis of the fragmentation pattern of the mass spectra of the fragments from peptides with oxidized methionine is loss of 64 Da, which corresponds to loss of CH3SOH from the methionine sulfoxide. These fragments are useful in identifying peptides that include oxidized methionine residues.

Differential effects of phthalates on the testis and the liver.

PubMed

Bhattacharya, Nandini; Dufour, Jannette M; Vo, My-Nuong; Okita, Janice; Okita, Richard; Kim, Kwan Hee

2005-03-01

Phthalates have been shown to elicit contrasting effects on the testis and the liver, causing testicular degeneration and promoting abnormal hepatocyte proliferation and carcinogenesis. In the present study, we compared the effects of phthalates on testicular and liver cells to better understand the mechanisms by which phthalates cause testicular degeneration. In vivo treatment of rats with di-(2-ethylhexyl) phthalate (DEHP) caused a threefold increase of germ cell apoptosis in the testis, whereas apoptosis was not changed significantly in livers from the same animals. Western blot analyses revealed that peroxisome proliferator-activated receptor (PPAR) alpha is equally abundant in the liver and the testis, whereas PPAR gamma and retinoic acid receptor (RAR) alpha are expressed more in the testis. To determine whether the principal metabolite of DEHP, mono-(2-ethylhexyl) phthalate (MEHP), or a strong peroxisome proliferator, 4-chloro-6(2,3-xylindino)-2-pyrimidinylthioacetic acid (Wy-14,643), have a differential effect in Sertoli and liver cells by altering the function of RAR alpha and PPARs, their nuclear trafficking patterns were compared in Sertoli and liver cells after treatment. Both MEHP and Wy-14,643 increased the nuclear localization of PPAR alpha and PPAR gamma in Sertoli cells, but they decreased the nuclear localization of RAR alpha, as previously shown. Both PPAR alpha and PPAR gamma were in the nucleus and cytoplasm of liver cells, but RAR alpha was predominant in the cytoplasm, regardless of the treatment. At the molecular level, MEHP and Wy-14,643 reduced the amount of phosphorylated mitogen-activated protein kinase (activated MAPK) in Sertoli cells. In comparison, both MEHP and Wy-14,643 increased phosphorylated MAPK in liver cells. These results suggest that phthalates may cause contrasting effects on the testis and the liver by differential activation of the MAPK pathway, RAR alpha, PPAR alpha, and PPAR gamma in these organs.

Discovery of an Oxybenzylglycine Based Peroxisome Proliferator Activated Receptor Alpha Selective

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

Li, J.; Kennedy, L; Shi, Y

2010-01-01

An 1,3-oxybenzylglycine based compound 2 (BMS-687453) was discovered to be a potent and selective peroxisome proliferator activated receptor (PPAR) {alpha} agonist, with an EC{sub 50} of 10 nM for human PPAR{alpha} and {approx}410-fold selectivity vs human PPAR{gamma} in PPAR-GAL4 transactivation assays. Similar potencies and selectivity were also observed in the full length receptor co-transfection assays. Compound 2 has negligible cross-reactivity against a panel of human nuclear hormone receptors including PPAR{delta}. Compound 2 demonstrated an excellent pharmacological and safety profile in preclinical studies and thus was chosen as a development candidate for the treatment of atherosclerosis and dyslipidemia. The X-ray cocrystalmore » structures of the early lead compound 12 and compound 2 in complex with PPAR{alpha} ligand binding domain (LBD) were determined. The role of the crystal structure of compound 12 with PPAR{alpha} in the development of the SAR that ultimately resulted in the discovery of compound 2 is discussed.« less

Brain Ischemia Induces Diversified Neuroantigen-Specific T-Cell Responses That Exacerbate Brain Injury.

PubMed

Jin, Wei-Na; Gonzales, Rayna; Feng, Yan; Wood, Kristofer; Chai, Zhi; Dong, Jing-Fei; La Cava, Antonio; Shi, Fu-Dong; Liu, Qiang

2018-06-01

Autoimmune responses can occur when antigens from the central nervous system are presented to lymphocytes in the periphery or central nervous system in several neurological diseases. However, whether autoimmune responses emerge after brain ischemia and their impact on clinical outcomes remains controversial. We hypothesized that brain ischemia facilitates the genesis of autoimmunity and aggravates ischemic brain injury. Using a mouse strain that harbors a transgenic T-cell receptor to a central nervous system antigen, MOG 35-55 (myelin oligodendrocyte glycoprotein) epitope (2D2), we determined the anatomic location and involvement of antigen-presenting cells in the development of T-cell reactivity after brain ischemia and how T-cell reactivity impacts stroke outcome. Transient middle cerebral artery occlusion and photothrombotic stroke models were used in this study. We also quantified the presence and status of T cells from brain slices of ischemic patients. By coupling transfer of labeled MOG 35-55 -specific (2D2) T cells with tetramer tracking, we show an expansion in reactivity of 2D2 T cells to MOG 91-108 and MOG 103-125 in transient middle cerebral artery occlusion and photothrombotic stroke models. This reactivity and T-cell activation first occur locally in the brain after ischemia. Also, microglia act as antigen-presenting cells that effectively present MOG antigens, and depletion of microglia ablates expansion of 2D2 reactive T cells. Notably, the adoptive transfer of neuroantigen-experienced 2D2 T cells exacerbates Th1/Th17 responses and brain injury. Finally, T-cell activation and MOG-specific T cells are present in the brain of patients with ischemic stroke. Our findings suggest that brain ischemia activates and diversifies T-cell responses locally, which exacerbates ischemic brain injury. © 2018 The Authors.

Functional assessment of recombinant human alpha(2)-adrenoceptor subtypes with cytosensor microphysiometry.

PubMed

Pihlavisto, M; Scheinin, M

1999-12-03

We applied the Cytosensor Microphysiometry system to study the three human alpha(2)-adrenoceptor subtypes, alpha(2A), alpha(2B) and alpha(2C), expressed in Chinese hamster ovary (CHO) cells, and assessed its potential in the quantitative monitoring of agonist activity. The natural full agonist, (-)-noradrenaline, was used to define agonist efficacy. The imidazole derivative dexmedetomidine was a potent full agonist of all three receptor subtypes. The imidazolines clonidine and UK 14,304 (5-bromo-N-(4, 5-dihydro-1H-imidazol-2-yl)-6-quinoxalinamine) appeared to be partial agonists at alpha(2B)-adrenoceptors (E(max) approximately 60% of (-)-noradrenaline) but full agonists at alpha(2A)- and alpha(2C)-adrenoceptors. The responses mediated by all three alpha(2)-adrenoceptor subtypes were partly inhibited by the sodium-hydrogen (Na(+)/H(+)) exchange inhibitor, MIA (5-(N-methyl-N-isobutyl)-amiloride). The agonist responses were totally abolished by pretreatment with pertussis toxin in cells with alpha(2A)- and alpha(2C)-adrenoceptors, and partly abolished in cells with alpha(2B)-adrenoceptors. The residual signal in alpha(2B)-cells was sensitive to the intracellular Ca(2+)chelator, BAPTA (1,2-bis(2-aminophenoxy)ethane-N,N,N,N-tetraacetic acid acetoxymethyl ester). Cholera toxin (which acts on G(s)-proteins) had no effect on the agonist responses. The results suggest that the extracellular acidification responses mediated by all three human alpha(2)-adrenoceptor subtypes are dependent on Na(+)/H(+)exchange and G(i/o) pathways, and that alpha(2B)-adrenoceptors are capable of coupling to another, G(i/o)-independent and Ca(2+)-dependent signaling pathway.

Dissecting the role of matrix metalloproteinases (MMP) and integrin alpha(v)beta3 in angiogenesis in vitro: absence of hemopexin C domain bioactivity, but membrane-Type 1-MMP and alpha(v)beta3 are critical.

PubMed

Nisato, Riccardo E; Hosseini, Ghamartaj; Sirrenberg, Christian; Butler, Georgina S; Crabbe, Thomas; Docherty, Andrew J P; Wiesner, Matthias; Murphy, Gillian; Overall, Christopher M; Goodman, Simon L; Pepper, Michael S

2005-10-15

Matrix metalloproteinase (MMP)-2 and its hemopexin C domain autolytic fragment (also called PEX) have been proposed to be crucial for angiogenesis. Here, we have investigated the dependency of in vitro angiogenesis on MMP-mediated extracellular proteolysis and integrin alpha(v)beta3-mediated cell adhesion in a three-dimensional collagen I model. The hydroxamate-based synthetic inhibitors BB94, CT1399, and CT1847 inhibited endothelial cell invasion, as did neutralizing anti-membrane-type 1-MMP (MT1-MMP) antibodies and tissue inhibitor of MMP (TIMP)-2 and TIMP-3 but not TIMP-1. This confirmed the pivotal importance of MT1-MMP over other MMPs in this model. Invasion was also inhibited by a nonpeptidic antagonist of integrin alpha(v)beta3, EMD 361276. Although PEX strongly inhibited pro-MMP-2 activation, when contaminating lipopolysaccharide was neutralized, PEX neither affected angiogenesis nor bound integrin alpha(v)beta(3). Moreover, no specific binding of pro-MMP-2 to integrin alpha(v)beta3 was found, whereas only one out of four independently prepared enzymatically active MMP-2 preparations could bind integrin alpha(v)beta3 , and this in a PEX-independent manner. Likewise, integrin alpha(v)beta3 -expressing cells did not bind MMP-2-coated surfaces. Hence, these findings show that endothelial cell invasion of collagen I gels is MT1-MMP and alpha(v)beta3 - dependent but MMP-2 independent and does not support a role for PEX in alpha(v)beta3 integrin binding or in modulating angiogenesis in this system.

Mechanistic basis for estrogenic effects in fathead minnow (Pimephales promelas) following exposure to the androgen 17alpha-methyltestosterone: conversion of 17alpha-methyltestosterone to 17alpha-methylestradiol.

PubMed

Hornung, Michael W; Jensen, Kathleen M; Korte, Joseph J; Kahl, Michael D; Durhan, Elizabeth J; Denny, Jeffrey S; Henry, Tala R; Ankley, Gerald T

2004-01-07

Exposure of adult fathead minnows (Pimephales promelas) to the androgen 17alpha-methyltestosterone (MT) produces both androgenic and estrogenic effects, manifested as nuptial tubercle formation in females, and vitellogenin production in males and females, respectively. The present study was conducted to determine if the unanticipated estrogenic effects are produced by conversion of MT via aromatase activity to 17alpha-methylestradiol (ME2). Aromatase activity at the end of a 7-day waterborne MT exposure (20, 200microg/l) was significantly decreased in ovarian microsomes and brain homogenates from exposed fish, to about 30-50% of control activity. Although aromatase activity was decreased by 7 days, it is possible that the conversion of MT to ME2 occurred soon after initial exposure. In support of this, ME2 was detected in plasma samples of the fish following the 7-day exposure, confirming their ability convert the androgen MT to the estrogen ME2. The concentration of ME2 in plasma was within the range of plasma 17ss-estradiol (E2) found in control female fathead minnows (4-5ng/ml). These results, in conjunction with competitive binding assays that indicate ME2 binds to the fathead minnow estrogen receptor with a relative binding affinity of 68.3% of E2, support the hypothesis that aromatization of MT to ME2 contributes to the estrogenic effects in fathead minnows following exposure to this androgen.

Artificial ligand binding within the HIF2[alpha] PAS-B domain of the HIF2 transcription factor

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

Scheuermann, Thomas H.; Tomchick, Diana R.; Machius, Mischa

2009-05-12

The hypoxia-inducible factor (HIF) basic helix-loop-helix Per-aryl hydrocarbon receptor nuclear translocator (ARNT)-Sim (bHLH-PAS) transcription factors are master regulators of the conserved molecular mechanism by which metazoans sense and respond to reductions in local oxygen concentrations. In humans, HIF is critically important for the sustained growth and metastasis of solid tumors. Here, we describe crystal structures of the heterodimer formed by the C-terminal PAS domains from the HIF2{alpha} and ARNT subunits of the HIF2 transcription factor, both in the absence and presence of an artificial ligand. Unexpectedly, the HIF2{alpha} PAS-B domain contains a large internal cavity that accommodates ligands identified frommore » a small-molecule screen. Binding one of these ligands to HIF2{alpha} PAS-B modulates the affinity of the HIF2{alpha}:ARNT PAS-B heterodimer in vitro. Given the essential role of PAS domains in forming active HIF heterodimers, these results suggest a presently uncharacterized ligand-mediated mechanism for regulating HIF2 activity in endogenous and clinical settings.« less

Type-I interferon receptor expression: its circadian rhythm and downregulation after interferon-alpha administration in peripheral blood cells from renal cancer patients.

PubMed

Shiba, Masahiro; Nonomura, Norio; Nakai, Yasutomo; Nakayama, Masashi; Takayama, Hitoshi; Inoue, Hitoshi; Tsujimura, Akira; Nishimura, Kazuo; Okuyama, Akihiko

2009-04-01

To investigate the regulation of interferon-alpha (IFN-alpha) receptor expression in metastatic renal cell carcinoma (RCC) after IFN-alpha administration. Blood sampling was carried out in eight patients with metastatic RCC and six healthy volunteers. Flow-cytometric analysis using a monoclonal antibody against the active subunit of the type-I IFN-alpha receptor (IFNAR2) was carried out to examine the circadian rhythm of IFNAR2 expression in peripheral blood mononuclear cells (PBMC) as well as its downregulation after IFN-alpha administration. According to its circadian rhythm IFNAR2 in PBMC had a peak expression at night. Once IFN-alpha is administered, IFNAR2 levels in PBMC showed downregulation within 48 h and recovered within another 48 h. Our findings might support the establishment of an optimal schedule for IFN-alpha administration.

Effects of a caffeine-free Cola nitida nuts extract on elastase/alpha-1-proteinase inhibitor balance.

PubMed

Daels-Rakotoarison, Dominique A; Kouakou, Gisèle; Gressier, Bernard; Dine, Thierry; Brunet, Claude; Luyckx, Michel; Bailleul, François; Trotin, Francis

2003-11-01

In an infection, polymorphonuclear neutrophils (PMN) become activated and they produce oxidizing compounds and elastase in the extracellular medium. Alpha-1-proteinase inhibitor (alpha1PI), a protease inhibitor which is inactivated by oxidants, is the main endogenous inhibitor of elastase helping to limit excessive elastase activity. This study evaluates the ability of a plant extract, Cola nitida nuts, to protect alpha1PI from inactivation by oxidizing compounds as reactive oxygen species. On the one hand, we have evaluated the direct effect of cola nut extract on neutrophil elastase, and on the H(2)O(2) and myeloperoxidase (MPO)-H(2)O(2) system via cell-free systems. Results showed that cola nut extract scavenges H(2)O(2) and therefore protects alpha1PI from HOCl which is produced from the MPO-H(2)O(2) system. Experiments also showed that cola extract has the capacity to limit elastase activity. On the other hand, we have worked on cellular systems including isolated PMN with the aim to study the effect of cola extract on PMN metabolism. PMN were stimulated with PMA, calcium ionophore or fMLP. Each stimulant possesses its own stimulation pathway. According to the inhibitory concentration obtained at 50%, the results on cellular systems led to the conclusion that cola extract can reduce elastase liberation from PMN. It can then be concluded that cola nut extract can protect alpha1PI from inactivation, and has an effect both on elastase liberation and elastase activity. The cola nut extract effect is rather biased towards a reduction in elastase release, thus limiting the injurious effects caused by this enzyme.

Mouse interleukin-2 structure-function studies: substitutions in the first alpha-helix can specifically inactivate p70 receptor binding and mutations in the fifth alpha-helix can specifically inactivate p55 receptor binding.

PubMed Central

Zurawski, S M; Zurawski, G

1989-01-01

The function of two alpha-helical regions of mouse interleukin-2 were analyzed by saturation substitution analysis. The functional parts of the first alpha-helix (A) was defined as residues 31-39 by the observation that proline substitutions within this region inactivate the protein. Four residues within alpha-helix A, Leu31, Asp34, Leu35 and Leu38, were found to be crucial for biological activity. Structural modeling suggested that these four residues are clustered on one face of alpha-helix A. Residues 31 and 35 had to remain hydrophobic for the molecule to be functional. At residue 38 there was a preference for hydrophobic side chain residues, while at residue 34 some small side chain residues as well as acidic or amide side chain residues were functionally acceptable. Inactivating changes at residue 34 had no effect upon the ability of the protein to interact with the p55 receptor. Disruption of the fifth alpha-helix (E), which had little effect upon biological activity, resulted in an inability of the protein to interact with the p55 receptor. Mutagenesis of the alpha-helix E region demonstrated that alpha-helicity and the nature of the side chain residues in this region were unimportant for biological activity. The region immediately proximal to alpha-helix E was important only for the single intramolecular disulfide linkage. PMID:2583124

Substitutional and Interstitial Diffusion in alpha2-Ti3Al(O)

NASA Technical Reports Server (NTRS)

Copland, Evan; Young, David J.; Gleeson, Brian; Jacobson, Nathan

2007-01-01

The reaction between Al2O3 and alpha2-Ti3Al was studied with a series of Al2O3/alpha2-Ti3Al multiphase diffusion couples annealed at 900, 1000 and 1100 C. The diffusion-paths were found to strongly depend on alpha2- Ti3Al(O) composition. For alloys with low oxygen concentrations the reaction involved the reduction of Al2O3, the formation of a gamma-TiAl reaction-layer and diffusion of Al and O into the alpha2-Ti3Al substrate. Measured concentration profiles across the interaction-zone showed "up-hill" diffusion of O in alpha2-Ti3Al(O) indicating a significant thermodynamic interaction between O and Al, Ti or both. Diffusion coefficients for the interstitial O in alpha2-Ti3Al(O) were determined independently from the interdiffusion of Ti and Al on the substitutional lattice. Diffusion coefficients are reported for alpha2-Ti3Al(O) as well as gamma-TiAl. Interpretation of the results were aided with the subsequent measurement of the activities of Al, Ti and O in alpha 2-Ti3Al(O) by Knudsen effusion-cell mass spectrometry.

Hydrophobic interaction between the SH2 domain and the kinase domain is required for the activation of Csk.

PubMed

Mikkola, Esa T; Gahmberg, Carl G

2010-06-18

The protein tyrosine kinase C-terminal Src kinase (Csk) is activated by the engagement of its Src homology (SH) 2 domain. However, the molecular mechanism required for this is not completely understood. The crystal structure of the active Csk indicates that Csk could be activated by contact between the SH2 domain and the beta3-alphaC loop in the N-terminal lobe of the kinase domain. To study the importance of this interaction for the SH2-domain-mediated activation of Csk, we mutated the amino acid residues forming the contacts between the SH2 domain and the beta3-alphaC loop. The mutation of the beta3-alphaC loop Ala228 to glycine and of the SH2 domain Tyr116, Tyr133, Leu138, and Leu149 to alanine resulted in the inability of the SH2 domain ligand to activate Csk. Furthermore, the overexpressed Csk mutants A228G, Y133A/Y116A, L138A, and L149A were unable to efficiently inactivate endogenous Src in human embryonic kidney 293 cells. The results suggest that the SH2-domain-mediated activation of Csk is dependent on the binding of the beta3-alphaC loop Ala228 to the hydrophobic pocket formed by the side chains of Tyr116, Tyr133, Leu138, and Leu149 on the surface of the SH2 domain. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Importance of agonists in alpha-adrenoceptor classification and localisation of alpha1-adrenoceptors in human prostate.

PubMed

McGrath, J C; Naghadeh, M A; Pediani, J D; Mackenzie, J F; Daly, C J

1999-01-01

alpha-Adrenoceptor blocker drugs are commonly used in the clinical (non-surgical) treatment of BPH. alpha1-adrenoceptors were originally sub-divided using agonists but, subsequently, were sub-divided using only antagonists in ligand-ligand interactions, which did not require agonists at all. Ultimately, proof that adrenoceptors are functional receptors for the natural ligands, noradrenaline and adrenaline, requires that agonists be used. The earlier excitement engendered by finding varying agonist potency series in different tissues has not been revisited to place it in the context of current concepts of alpha1-adrenoceptor subtypes. This review will consider the advantages and limitations of different agonists for the study of alpha1-adrenoceptor subtypes including 'extreme' examples where the archetypal alpha1-adrenoceptor agonist phenylephrine activates alpha2-adrenoceptors and others where UK14304, often the alpha2-adrenoceptor agonist of choice, activates alpha1-adrenoceptors. New work will also be presented showing the interaction between agonists and the fluorescent alpha1-adrenoceptor antagonist QAPB. This introduces the novel point of view of studying the displacement of antagonists by agonists. Possible errors in antagonist classification arising from complexity in the actions of agonists and the recently developed method of fluorescent ligand binding on isolated living human prostatic smooth muscle cells will be discussed.

An Alpha-1A Adrenergic Receptor Agonist Prevents Acute Doxorubicin Cardiomyopathy in Male Mice.

PubMed

Montgomery, Megan D; Chan, Trevor; Swigart, Philip M; Myagmar, Bat-Erdene; Dash, Rajesh; Simpson, Paul C

2017-01-01

Alpha-1 adrenergic receptors mediate adaptive effects in the heart and cardiac myocytes, and a myocyte survival pathway involving the alpha-1A receptor subtype and ERK activation exists in vitro. However, data in vivo are limited. Here we tested A61603 (N-[5-(4,5-dihydro-1H-imidazol-2-yl)-2-hydroxy-5,6,7,8-tetrahydronaphthalen-1-yl]methanesulfonamide), a selective imidazoline agonist for the alpha-1A. A61603 was the most potent alpha-1-agonist in activating ERK in neonatal rat ventricular myocytes. A61603 activated ERK in adult mouse ventricular myocytes and protected the cells from death caused by the anthracycline doxorubicin. A low dose of A61603 (10 ng/kg/d) activated ERK in the mouse heart in vivo, but did not change blood pressure. In male mice, concurrent subcutaneous A61603 infusion at 10 ng/kg/d for 7 days after a single intraperitoneal dose of doxorubicin (25 mg/kg) increased survival, improved cardiac function, heart rate, and cardiac output by echocardiography, and reduced cardiac cell necrosis and apoptosis and myocardial fibrosis. All protective effects were lost in alpha-1A-knockout mice. In female mice, doxorubicin at doses higher than in males (35-40 mg/kg) caused less cardiac toxicity than in males. We conclude that the alpha-1A-selective agonist A61603, via the alpha-1A adrenergic receptor, prevents doxorubicin cardiomyopathy in male mice, supporting the theory that alpha-1A adrenergic receptor agonists have potential as novel heart failure therapies.

LaaA, a novel high-active alkalophilic alpha-amylase from deep-sea bacterium Luteimonas abyssi XH031(T).

PubMed

Song, Qinghao; Wang, Yan; Yin, Chong; Zhang, Xiao-Hua

2016-08-01

Alpha-amylase is a kind of broadly used industrial enzymes, most of which have been exploited from terrestrial organism. Comparatively, alpha-amylase from marine environment was largely undeveloped. In this study, a novel alkalophilic alpha-amylase with high activity, Luteimonas abyssi alpha-amylase (LaaA), was cloned from deep-sea bacterium L. abyssi XH031(T) and expressed in Escherichia coli BL21. The gene has a length of 1428bp and encodes 475 amino acids with a 35-residue signal peptide. The specific activity of LaaA reached 8881U/mg at the optimum pH 9.0, which is obvious higher than other reported alpha-amylase. This enzyme can remain active at pH levels ranging from 6.0 to 11.0 and temperatures below 45°C, retaining high activity even at low temperatures (almost 38% residual activity at 10°C). In addition, 1mM Na(+), K(+), and Mn(2+) enhanced the activity of LaaA. To investigate the function of potential active sites, R227G, D229K, E256Q/H, H327V and D328V mutants were generated, and the results suggested that Arg227, Asp229, Glu256 and Asp328 were total conserved and essential for the activity of alpha-amylase LaaA. This study shows that the alpha-amylase LaaA is an alkali-tolerant and high-active amylase with strong potential for use in detergent industry. Copyright © 2016 Elsevier Inc. All rights reserved.

The effects of 3,4-methylenedioxymethamphetamine (MDMA) on nicotinic receptors: Intracellular calcium increase, calpain/caspase 3 activation, and functional upregulation

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

Garcia-Rates, Sara; Camarasa, Jordi; Sanchez-Garcia, Ana I.

2010-05-01

Previous work by our group demonstrated that homomeric alpha7 nicotinic acetylcholine receptors (nAChR) play a role in the neurotoxicity induced by 3,4-methylenedioxymethamphetamine (MDMA), as well as the binding affinity of this drug to these receptors. Here we studied the effect of MDMA on the activation of nAChR subtypes, the consequent calcium mobilization, and calpain/caspase 3 activation because prolonged Ca{sup 2+} increase could contribute to cytotoxicity. As techniques, we used fluorimetry in Fluo-4-loaded PC12 cells and electrophysiology in Xenopus oocytes. MDMA produced a rapid and sustained increase in calcium without reaching the maximum effect induced by ACh. It also concentration-dependently inhibitedmore » the response induced by ACh, nicotine, and the specific alpha7 agonist PNU 282987 with IC{sub 50} values in the low micromolar range. Similarly, MDMA induced inward currents in Xenopus oocytes transfected with human alpha7 but not with alpha4beta2 nAChR and inhibited ACh-induced currents in both receptors in a concentration-dependent manner. The calcium response was inhibited by methyllycaconitine (MLA) and alpha-bungarotoxin but not by dihydro-beta-erythroidine. These results therefore indicate that MDMA acts as a partial agonist on alpha7 nAChRs and as an antagonist on the heteromeric subtypes. Subsequently, calcium-induced Ca{sup 2+} release from the endoplasmic reticulum and entry through voltage-operated calcium channels are also implicated as proved using specific antagonists. In addition, treatment with MDMA for 24 h significantly increased basal Ca{sup 2+} levels and induced an increase in alpha-spectrin breakdown products, which indicates that calpain and caspase 3 were activated. These effects were inhibited by pretreatment with MLA. Moreover, pretreatment with MDMA induced functional upregulation of calcium responses to specific agonists of both heteromeric and alpha7 nAChR. Sustained calcium entry and calpain activation could favor the activation of Ca{sup 2+}-dependent enzymes such as protein kinase C and nitric oxide synthase, which are involved in the generation of ROS and the blockade of the dopamine transporter. This, together with caspase 3 activation, must play a role in MDMA-induced cytotoxicity.« less

Thermodynamic studies of drug-alpha-cyclodextrin interactions in water at 298.15 K: promazine hydrochloride/chlorpromazine hydrochloride + alpha-cyclodextrin + H(2)O systems.

PubMed

Terdale, Santosh S; Dagade, Dilip H; Patil, Kesharsingh J

2007-12-06

Data on osmotic coefficients have been obtained for a binary aqueous solution of two drugs, namely, promazine hydrochloride (PZ) and chlorpromazine hydrochloride (CPZ) using a vapor pressure osmometer at 298.15 K. The observed critical micelle concentration (cmc) agrees excellently with the available literature data. The measurements are extended to aqueous ternary solutions containing fixed a concentration of alpha-cyclodextrin (alpha-CD) of 0.1 mol kg(-1) and varied concentrations (approximately 0.005-0.2 mol kg(-1)) of drugs at 298.15 K. It has been found that the cmc values increase by the addition of alpha-CD. The mean molal activity coefficients of the ions and the activity coefficient of alpha-CD in binary as well as ternary solutions were obtained, which have been further used to calculate the excess Gibbs free energies and transfer Gibbs free energies. The lowering of the activity coefficients of ions and of alpha-CD is attributed to the existence of host-guest (inclusion)-type complex equilibria. It is suggested that CPZ forms 2:1 and 1:1 complexed species with alpha-CD, while PZ forms only 1:1 complexed species. The salting constant (ks) values are determined at 298.15 K for promazine-alpha-CD and chlorpromazine-alpha-CD complexes, respectively, by following the method based on the application of the McMillan-Mayer theory of virial coefficients to transfer free energy data. It is noted that the presence of chlorine in the drug molecule imparts better complexing capacity, the effect of which gets attenuated as a result of hydrophobic interaction. The results are discussed from the point of view of associative equilibria before the cmc and complexed equilibria for binary and ternary solutions, respectively.

Tumor necrosis factor (cachectin) is an endogenous pyrogen and induces production of interleukin 1.

PubMed

Dinarello, C A; Cannon, J G; Wolff, S M; Bernheim, H A; Beutler, B; Cerami, A; Figari, I S; Palladino, M A; O'Connor, J V

1986-06-01

Recombinant human tumor necrosis factor (rTNF alpha) injected intravenously into rabbits produces a rapid-onset, monophasic fever indistinguishable from the fever produced by rIL-1. On a weight basis (1 microgram/kg) rTNF alpha and rIL-1 produce the same amount of fever and induce comparable levels of PGE2 in rabbit hypothalamic cells in vitro; like IL-1, TNF fever is blocked by drugs that inhibit cyclooxygenase. At higher doses (10 micrograms/kg) rTNF alpha produces biphasic fevers. The first fever reaches peak elevation 45-55 min after bolus injection and likely represents a direct action on the thermoregulatory center. During the second fever peak (3 h later), a circulating endogenous pyrogen can be shown present using passive transfer of plasma into fresh rabbits. This likely represents the in vivo induction of IL-1. In vitro, rTNF alpha induces the release of IL-1 activity from human mononuclear cells with maximal production observed at 50-100 ng/ml of rTNF alpha. In addition, rTNF alpha and rIFN-gamma have a synergistic effect on IL-1 production. The biological activity of rTNF alpha could be distinguished from IL-1 in three ways: the monophasic pyrogenic activity of rIL-1 was destroyed at 70 degrees C, whereas rTNF alpha remained active; anti-IL-1 neutralized IL-1 but did recognize rTNF alpha or natural cachectin nor neutralize its cytotoxic effect; and unlike IL-1, rTNF alpha was not active in the mitogen-stimulated T cell proliferation assay. The possibility that endotoxin was responsible for rTNF alpha fever and/or the induction of IL-1 was ruled-out in several studies: rTNF alpha produced fever in the endotoxin-resistant C3H/HeJ mice; the IL-1-inducing property of rTNF alpha was destroyed either by heat (70 degrees C) or trypsinization, and was unaffected by polymyxin B; pyrogenic tolerance to daily injections of rTNF alpha did not occur; levels of endotoxin, as determined in the Limulus amebocyte lysate, were below the minimum rabbit pyrogen dose; and these levels of endotoxin were confirmed by gas chromatography/mass spectrometry analysis for the presence of beta-hydroxymyristic acid. Although rTNF alpha is not active in T cell proliferation assays, it may mimic IL-1 in a T cell assay, since high concentrations of rTNF alpha induced IL-1 from epithelial or macrophagic cells in the thymocyte preparations. These studies show that TNF (cachectin) is another endogenous pyrogen which, like IL-1 and IFN-alpha, directly stimulate hypothalamic PGE2 synthesis. In addition, rTNF alpha is an endogenous inducer of IL-1.(ABSTRACT TRUNCATED AT 400 WORDS)

Effect of TNF{alpha} on activities of different promoters of human apolipoprotein A-I gene

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

Orlov, Sergey V., E-mail: serge@iem.sp.ru; Department of Embryology, St. Petersburg State University, 199034 St. Petersburg; Mogilenko, Denis A.

2010-07-23

Research highlights: {yields} TNF{alpha} stimulates the distal alternative promoter of human apoA-I gene. {yields} TNF{alpha} acts by weakening of promoter competition within apoA-I gene (promoter switching). {yields} MEK1/2 and nuclear receptors PPAR{alpha} and LXRs take part in apoA-I promoter switching. -- Abstract: Human apolipoprotein A-I (ApoA-I) is a major structural and functional protein component of high-density lipoproteins. The expression of the apolipoprotein A-I gene (apoA-I) in hepatocytes is repressed by pro-inflammatory cytokines such as IL-1{beta} and TNF{alpha}. Recently, two novel additional (alternative) promoters for human apoA-I gene have been identified. Nothing is known about the role of alternative promoters inmore » TNF{alpha}-mediated downregulation of apoA-I gene. In this article we report for the first time about the different effects of TNF{alpha} on two alternative promoters of human apoA-I gene. Stimulation of HepG2 cells by TNF{alpha} leads to activation of the distal alternative apoA-I promoter and downregulation of the proximal alternative and the canonical apoA-I promoters. This effect is mediated by weakening of the promoter competition within human apoA-I 5'-regulatory region (apoA-I promoter switching) in the cells treated by TNF{alpha}. The MEK1/2-ERK1/2 cascade and nuclear receptors PPAR{alpha} and LXRs are important for TNF{alpha}-mediated apoA-I promoter switching.« less

NOD2 and TLR2 ligands trigger the activation of basophils and eosinophils by interacting with dermal fibroblasts in atopic dermatitis-like skin inflammation

PubMed Central

Jiao, Delong; Wong, Chun-Kwok; Qiu, Huai-Na; Dong, Jie; Cai, Zhe; Chu, Man; Hon, Kam-Lun; Tsang, Miranda Sin-Man; Lam, Christopher Wai-Kei

2016-01-01

The skin of patients with atopic dermatitis (AD) has a unique predisposition for colonization by Staphylococcus aureus (S. aureus), which contributes to the inflammation and grim prognosis of AD. Although the mechanism underlying the S. aureus-induced exacerbation of AD remains unclear, recent studies have found a pivotal role for pattern recognition receptors in regulating the inflammatory responses in S. aureus infection. In the present study, we used a typical mouse model of AD-like skin inflammation and found that S. aureus-associated nucleotide-binding oligomerization domain-containing protein 2 (NOD2) and toll-like receptor 2 (TLR2) ligands exacerbated AD-like symptoms, which were further deteriorated by the in vivo expansion of basophils and eosinophils. Subsequent histological analyses revealed that dermal fibroblasts were pervasive in the AD-like skin lesions. Co-culture of human dermal fibroblasts with basophils and eosinophils resulted in a vigorous cytokine/chemokine response to the NOD2/TLR2 ligands and the enhanced expression of intercellular adhesion molecule-1 on the dermal fibroblasts. Basophils and eosinophils were primarily responsible for the AD-related cytokine/chemokine expression in the co-cultures. Direct intercellular contact was necessary for the crosstalk between basophils and dermal fibroblasts, while soluble mediators were sufficient to mediate the eosinophil–fibroblast interactions. Moreover, the intracellular p38 mitogen-activated protein kinase, extracellular signal-regulated kinase, and nuclear factor-kappa B signaling pathways were essential for NOD2/TLR2 ligand-mediated activation of basophils, eosinophils, and dermal fibroblasts in AD-related inflammation. This study provides the evidence of NOD2/TLR2-mediated exacerbation of AD through activation of innate immune cells and therefore sheds light on a novel mechanistic pathway by which S. aureus contributes to the pathophysiology of AD. PMID:26388234

COPD exacerbations associated with the modified Medical Research Council scale and COPD assessment test among Humana Medicare members

PubMed Central

Pasquale, Margaret K; Xu, Yihua; Baker, Christine L; Zou, Kelly H; Teeter, John G; Renda, Andrew M; Davis, Cralen C; Lee, Theodore C; Bobula, Joel

2016-01-01

Background The Global initiative for chronic Obstructive Lung Disease guidelines recommend assessment of COPD severity, which includes symptomatology using the modified Medical Research Council (mMRC) or COPD assessment test (CAT) score in addition to the degree of airflow obstruction and exacerbation history. While there is great interest in incorporating symptomatology, little is known about how patient reported symptoms are associated with future exacerbations and exacerbation-related costs. Methods The mMRC and CAT were mailed to a randomly selected sample of 4,000 Medicare members aged >40 years, diagnosed with COPD (≥2 encounters with International Classification of Dis eases-9th Edition Clinical Modification: 491.xx, 492.xx, 496.xx, ≥30 days apart). The exacerbations and exacerbation-related costs were collected from claims data during 365-day post-survey after exclusion of members lost to follow-up or with cancer, organ transplant, or pregnancy. A logistic regression model estimated the predictive value of exacerbation history and symptomatology on exacerbations during follow-up, and a generalized linear model with log link and gamma distribution estimated the predictive value of exacerbation history and symptomatology on exacerbation-related costs. Results Among a total of 1,159 members who returned the survey, a 66% (765) completion rate was observed. Mean (standard deviation) age among survey completers was 72.0 (8.3), 53.7% female and 91.2% white. Odds ratios for having post-index exacerbations were 3.06, 4.55, and 16.28 times for members with 1, 2, and ≥3 pre-index exacerbations, respectively, relative to members with 0 pre-index exacerbations (P<0.001 for all). The odds ratio for high vs low symptoms using CAT was 2.51 (P<0.001). Similarly, exacerbation-related costs were 73% higher with each incremental pre-index exacerbation, and over four fold higher for high-vs low-symptom patients using CAT (each P<0.001). The symptoms using mMRC were not statistically significant in either model (P>0.10). Conclusion The patient-reported symptoms contribute important information related to future COPD exacerbations and exacerbation-related costs beyond that explained by exacerbation history. PMID:26834468

Role of Fetuin-A in Breast Tumor Cell Growth

DTIC Science & Technology

2009-03-01

UniRef100_Q0IIK2 289 390 1.4 Transferrin UniRef100_Q9GLY6 18 24 1.3 Inter- alpha -trypsin inhibitor heavy chain2 UniRef100_Q3SZ57 25 33 1.3 Alpha - fetoprotein ...the first time that cell attachment is mediated only by fetuin-A and not its major contaminant which is alpha -2-macroglobulin. We also show both...fetuin-A and alpha -2-macroglobulin can activate PI3 kinase/Akt. 15. SUBJECT TERMS Mammary tumors;fetuin-A;Polyoma middle T antigen; genotyping

Chondrocyte heterogeneity: immunohistologically defined variation of integrin expression at different sites in human fetal knees.

PubMed

Salter, D M; Godolphin, J L; Gourlay, M S

1995-04-01

During development and at maturity different forms of cartilage vary in morphology and macromolecular content. This reflects heterogeneity of chondrocyte activity, in part involving differential interactions with the adjacent extracellular matrix via specialized cell surface receptors such as integrins. We undertook an immunohistological study on a series of human fetal knee joints to assess variation in the expression of integrins by chondrocytes and potential matrix ligands in articular, epiphyseal, growth plate, and meniscal cartilage. The results show that articular chondrocytes (beta 1+, beta 5 alpha V+, alpha 1+, alpha 2+/-, alpha 5+, weakly alpha 6+, alpha V+) differed from epiphyseal (beta 1+, beta 5 alpha V+, alpha 1+/-, alpha 2+/-, alpha 5+, alpha 6+, alpha V+) growth plate (beta 1+, beta 5 alpha V+, alpha 1-, alpha 2-, alpha 5+, alpha 6+, alpha V+), and meniscal cells (beta 1+, beta 5 alpha V+, alpha 1+, strongly alpha 2+, alpha 5+, alpha 6+, alpha V+ in expression of integrin subunits. There was no expression of beta 3, beta 4, beta 6, or alpha 3 by chondrocytes. These results differ from previous reports on the expression of integrins by adult articular cartilage, where alpha 2 and alpha 6 are not seen. Variation in distribution of matrix ligands was also seen. Fibronectin, laminin and Type VI collagen were expressed in all cartilages but there was restricted expression of tenascin, ED-A and ED-B fibronectin isoforms (articular cartilage and meniscus), and vitronectin (absent from growth plate cartilage). Regulated expression of integrins by chondrocytes, associated with changes in the pericellular matrix composition, is of potential importance in control of cartilage differentiation and function in health and disease.

Computer modeling of siRNA knockdown effects indicates an essential role of the Ca2+ channel alpha2delta-1 subunit in cardiac excitation-contraction coupling.

PubMed

Tuluc, Petronel; Kern, Georg; Obermair, Gerald J; Flucher, Bernhard E

2007-06-26

L-type Ca(2+) currents determine the shape of cardiac action potentials (AP) and the magnitude of the myoplasmic Ca(2+) signal, which regulates the contraction force. The auxiliary Ca(2+) channel subunits alpha(2)delta-1 and beta(2) are important regulators of membrane expression and current properties of the cardiac Ca(2+) channel (Ca(V)1.2). However, their role in cardiac excitation-contraction coupling is still elusive. Here we addressed this question by combining siRNA knockdown of the alpha(2)delta-1 subunit in a muscle expression system with simulation of APs and Ca(2+) transients by using a quantitative computer model of ventricular myocytes. Reconstitution of dysgenic muscle cells with Ca(V)1.2 (GFP-alpha(1C)) recapitulates key properties of cardiac excitation-contraction coupling. Concomitant depletion of the alpha(2)delta-1 subunit did not perturb membrane expression or targeting of the pore-forming GFP-alpha(1C) subunit into junctions between the outer membrane and the sarcoplasmic reticulum. However, alpha(2)delta-1 depletion shifted the voltage dependence of Ca(2+) current activation by 9 mV to more positive potentials, and it slowed down activation and inactivation kinetics approximately 2-fold. Computer modeling revealed that the altered voltage dependence and current kinetics exert opposing effects on the function of ventricular myocytes that in total cause a 60% prolongation of the AP and a 2-fold increase of the myoplasmic Ca(2+) concentration during each contraction. Thus, the Ca(2+) channel alpha(2)delta-1 subunit is not essential for normal Ca(2+) channel targeting in muscle but is a key determinant of normal excitation and contraction of cardiac muscle cells, and a reduction of alpha(2)delta-1 function is predicted to severely perturb normal heart function.

Effects of epidermal growth factor, interleukin 1 and nitric oxide on prostaglandin production by guinea-pig uterus.

PubMed

Keeble, J E; Poyser, N L

2002-08-01

Initial experiments in the present study investigated the effects of epidermal growth factor (EGF), interleukin 1beta (IL-1beta) and sodium nitroprusside (a nitric oxide donor) on the output of prostaglandins from guinea-pig uterus on day 7 of the oestrous cycle. Superfusion of day 7 guinea-pig uterus in vitro with either EGF or sodium nitroprusside increased the output of PGF(2alpha) and 6-keto-PGF(1alpha), but not of PGE(2). IL-1beta had no effect on the output of these three prostaglandins. EGF still increased the output of PGF(2alpha), but did not increase the output of 6-keto-PGF(1alpha) in a calcium-depleted superfusate. Subsequent experiments investigated the effect of sodium nitroprusside on contractile activity of day 7 guinea-pig uterus. Basal spontaneous activity of both the intact uterus and isolated myometrium superfused in vitro was low. Sodium nitroprusside increased the contractile activity of these tissues two- to fourfold. EGF did not affect the contractile activity of the uterus, indicating that sodium nitroprusside-induced contractions are not due to increased prostaglandin production. Overall, the findings indicate that EGF and nitric oxide may act as mediators in the mechanism by which oestradiol acting on a progesterone-primed uterus stimulates the increase in PGF(2alpha) production by the guinea-pig uterus necessary for luteolysis. Nitric oxide may increase the spontaneous activity of the uterus when this activity is low.

Exploring resting-state EEG brain oscillatory activity in relation to cognitive functioning in multiple sclerosis.

PubMed

Keune, Philipp M; Hansen, Sascha; Weber, Emily; Zapf, Franziska; Habich, Juliane; Muenssinger, Jana; Wolf, Sebastian; Schönenberg, Michael; Oschmann, Patrick

2017-09-01

Neurophysiologic monitoring parameters related to cognition in Multiple Sclerosis (MS) are sparse. Previous work reported an association between magnetoencephalographic (MEG) alpha-1 activity and information processing speed. While this remains to be replicated by more available electroencephalographic (EEG) methods, also other established EEG markers, e.g. the slow-wave/fast-wave ratio (theta/beta ratio), remain to be explored in this context. Performance on standard tests addressing information processing speed and attention (Symbol-Digit Modalities Test, SDMT; Test of Attention Performance, TAP) was examined in relation to resting-state EEG alpha-1 and alpha-2 activity and the theta/beta ratio in 25MS patients. Increased global alpha-1 and alpha-2 activity and an increased frontal theta/beta ratio (pronounced slow-wave relative to fast-wave activity) were associated with lower SDMT processing speed. In an exploratory analysis, clinically impaired attention was associated with a significantly increased frontal theta/beta ratio whereas alpha power did not show sensitivity to clinical impairment. EEG global alpha power and the frontal theta/beta ratio were both associated with attention. The theta/beta ratio involved potential clinical sensitivity. Resting-state EEG recordings can be obtained during the routine clinical process. The examined resting-state measures may represent feasible monitoring parameters in MS. This notion should be explored in future intervention studies. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Separate necdin domains bind ARNT2 and HIF1{alpha} and repress transcription

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

Friedman, Eitan R.; Fan Chenming

2007-11-09

PWS is caused by the loss of expression of a set of maternally imprinted genes including NECDIN (NDN). NDN is expressed in post-mitotic neurons and plays an essential role in PWS as mouse models lacking only the Ndn gene mimic aspects of this disease. Patients haploid for SIM1 develop a PW-like syndrome. Here, we report that NDN directly interacts with ARNT2, a bHLH-PAS protein and dimer partner for SIM1. We also found that NDN can interact with HIF1{alpha}. We showed that NDN can repress transcriptional activation mediated by ARNT2:SIM1 as well as ARNT2:HIF1{alpha}. The N-terminal 115 residues of NDN aremore » sufficient for interaction with the bHLH domains of ARNT2 or HIF1{alpha} but not for transcriptional repression. Using GAL4-NDN fusion proteins, we determined that NDN possesses multiple repression domains. We thus propose that NDN regulates neuronal function and hypoxic response by regulating the activities of the ARNT2:SIM1 and ARNT2:HIF1{alpha} dimers, respectively.« less

Discovery of an Oxybenzylglycine Based Peroxisome Proliferator Activated Receptor [alpha] Selective Agonist 2-((3-((2-(4-Chlorophenyl)-5-methyloxazol-4-yl)methoxy)benzyl)(methoxycarbonyl)amino)acetic Acid (BMS-687453)

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

Li, Jun; Kennedy, Lawrence J.; Shi, Yan

2010-04-12

An 1,3-oxybenzylglycine based compound 2 (BMS-687453) was discovered to be a potent and selective peroxisome proliferator activated receptor (PPAR) {alpha} agonist, with an EC{sub 50} of 10 nM for human PPAR{alpha} and 410-fold selectivity vs human PPAR{gamma} in PPAR-GAL4 transactivation assays. Similar potencies and selectivity were also observed in the full length receptor co-transfection assays. Compound 2 has negligible cross-reactivity against a panel of human nuclear hormone receptors including PPAR{delta}. Compound 2 demonstrated an excellent pharmacological and safety profile in preclinical studies and thus was chosen as a development candidate for the treatment of atherosclerosis and dyslipidemia. The X-ray cocrystalmore » structures of the early lead compound 12 and compound 2 in complex with PPAR{alpha} ligand binding domain (LBD) were determined. The role of the crystal structure of compound 12 with PPAR{alpha} in the development of the SAR that ultimately resulted in the discovery of compound 2 is discussed.« less

Different responses of spontaneous and stimulus-related alpha activity to ambient luminance changes.

PubMed

Benedetto, Alessandro; Lozano-Soldevilla, Diego; VanRullen, Rufin

2017-12-04

Alpha oscillations are particularly important in determining our percepts and have been implicated in fundamental brain functions. Oscillatory activity can be spontaneous or stimulus-related. Furthermore, stimulus-related responses can be phase- or non-phase-locked to the stimulus. Non-phase-locked (induced) activity can be identified as the average amplitude changes in response to a stimulation, while phase-locked activity can be measured via reverse-correlation techniques (echo function). However, the mechanisms and the functional roles of these oscillations are far from clear. Here, we investigated the effect of ambient luminance changes, known to dramatically modulate neural oscillations, on spontaneous and stimulus-related alpha. We investigated the effect of ambient luminance on EEG alpha during spontaneous human brain activity at rest (experiment 1) and during visual stimulation (experiment 2). Results show that spontaneous alpha amplitude increased by decreasing ambient luminance, while alpha frequency remained unaffected. In the second experiment, we found that under low-luminance viewing, the stimulus-related alpha amplitude was lower, and its frequency was slightly faster. These effects were evident in the phase-locked part of the alpha response (echo function), but weaker or absent in the induced (non-phase-locked) alpha responses. Finally, we explored the possible behavioural correlates of these modulations in a monocular critical flicker frequency task (experiment 3), finding that dark adaptation in the left eye decreased the temporal threshold of the right eye. Overall, we found that ambient luminance changes impact differently on spontaneous and stimulus-related alpha expression. We suggest that stimulus-related alpha activity is crucial in determining human temporal segmentation abilities. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Overview of the Impact of Depression and Anxiety in Chronic Obstructive Pulmonary Disease.

PubMed

Montserrat-Capdevila, Josep; Godoy, Pere; Marsal, Josep Ramon; Barbé, Ferran; Pifarré, Josep; Alsedà, Miquel; Ortega, Marta

2017-02-01

Anxiety and depression are common entities in patients diagnosed with COPD. However, the impact that they have on the exacerbation of illness is scarcely studied. To determine if the presence of anxiety and depression is associated with a greater risk of frequent exacerbation (≥2 per year) in patients diagnosed with COPD. A cohort study that analysed frequent exacerbation and associated factors in 512 patients monitored during 2 years. Exacerbations were defined as events that required antibiotic/s and/or systemic corticosteroids (moderate) or hospitalization (serious). Variables of interest were recorded for each patient, including anxiety and depression (Hospital Anxiety and Depression Scale), and we analysed their association with frequent exacerbation through the adjusted odds ratio (aOR) by means of a logistic regression model. The prevalence of anxiety/depression at the start of the study was of 15.6%. During the 2 years of monitoring, 77.9% of the patients suffered at least moderate-to-severe exacerbation. 54.1% were frequent exacerbators. Anxiety/depression were strongly associated with moderate-severe frequent exacerbation in the crude analysis (OR c  = 2.28). In the multivariate analysis, the risk factors also associated with frequent exacerbation were being overweight (aOR 2.78); obesity (aOR 3.02); diabetes (aOR 2.56) and the associated comorbidity (BODEx) (ORa = 1.45). The prevalence of anxiety/depression in COPD patients is high, and they are relevant risk factors in frequent exacerbation although the effect is lower in the multivariate analysis when adjusting for different variables strongly associated with exacerbation.

Radioresistance in murine solid tumors induced by interleukin-1

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

Braunschweiger, P.G.; Basrur, V.; Santos, O.

1996-02-01

Interleukin-1 (IL-1) has radioprotective activity in hematopoietic lineages and in other normal cell renewal systems, but little is known about the effects of IL-1{alpha} on the radiosensitivity of tumor cell populations. The present studies were conducted to investigate the effects of IL-1{alpha} on the radiosensitivity of clonogenic cells in RIF-1 and SCC-7 tumors. Radioresistance was detected within 2-4 h after administration of IL-1{alpha} (0.5 {mu}g/mouse, ip) and characterized by increases in D{sub 0}, D{sub q}, {alpha}/{Beta} and SF2. This radioresistance was similar to that seen in tumors rendered totally hypoxic before X irradiation. Tirapazamine, a hypoxic cell cytotoxin, and IL-1{alpha}more » had synergistic schedule-dependent antitumor activity in vivo, suggesting that IL-1-induced radioresistance in vivo is due to hypoxia. Radioresistance induced by IL-1{alpha} was transient, and the data suggested reoxygenation within 12 h. In vitro, IL-1{alpha} had no direct effect on the radiosensitivity of SCC-7 cells in tissue culture under aerobic conditions. However, an increase in D{sub 0}, {alpha}/{Beta} and SF2 was seen in clonogenic tumor cells from primary cultures treated with IL-1{alpha} under aerobic conditions. Superoxide dismutase and catalase prevented the induction of radioresistance by IL-1{alpha} in vitro, suggesting that oxidative responses from tumor macrophages after administration of IL-1{alpha} may be responsible for induced radioresistance by IL-1 in vitro. Although oxidant stress induced by IL-1 may play an important role in the activity of IL-1{alpha} both in vivo and in vitro in our models, the mechanisms by which such responses modulate tumor radiosensitivity in vivo and in vitro are likely quite different. 32 refs., 6 figs., 1 tab.« less

Glycosidases in Brachionus plicatilis (Rotifera).

PubMed

Kühle, K; Kleinow, W

1990-01-01

1. Tests for glycosidases were performed in homogenates of Brachionus plicatilis. 2. Hydrolytic activity was detected with the following substrates: (a) with synthetic substrates (NP = 4-nitrophenyl): NP-alpha- and NP-beta-D-glucopyranoside, NP-alpha- and NP-beta-D-galactopyranoside, NP-N-acetyl-beta-D-glucosaminide, NP-N-acetyl-beta-D-galactosaminide, NP-alpha- and NP-beta-D-mannopyranoside and NP-alpha-L-fucopyranoside; (b) with disaccharides: sucrose, maltose, trehalose, isomaltose, cellobiose, gentiobiose and lactose; (c) with polysaccharides: laminarine, carboxymethyl-cellulose, avicel, Micrococcus luteus (for lysozyme) and 4-nitrophenyl-alpha-D-maltoheptaoside (for amylase). 3. The pH dependence of the glycosidase activities was determined. 4. The distribution of enzyme activities within fractions from the homogenate was studied in order to localize them within the cell. 5. Proteins from Brachionus homogenate were separated by SDS-gel electrophoresis and the positions of the following glycosidase activities were detected by assays performed on the gels (estimated molecular weights in parentheses): alpha-glucosidase (250,000); beta-glucosidase (200,000); beta-galactosidase (70,000); N-acetyl-beta-glucosaminidase (60,000).

The Role of Prefrontal Dopamine D1 Receptors in the Neural Mechanisms of Associative Learning

PubMed Central

Puig, M. Victoria; Miller, Earl K.

2013-01-01

Summary Dopamine is thought to play a major role in learning. However, while dopamine D1 receptors (D1Rs) in the prefrontal cortex (PFC) have been shown to modulate working memory-related neural activity, their role in the cellular basis of learning is unknown. We recorded activity from multiple electrodes while injecting the D1R antagonist SCH23390 in the lateral PFC as monkeys learned visuomotor associations. Blocking D1Rs impaired learning of novel associations and decreased cognitive flexibility, but spared performance of already familiar associations. This suggests a greater role for prefrontal D1Rs in learning new, than performing familiar, associations. There was a corresponding greater decrease in neural selectivity and increase in alpha and beta oscillations in local field potentials for novel than familiar associations. Our results suggest that weak stimulation of D1Rs observed in aging and psychiatric disorders may impair learning and PFC function by reducing neural selectivity and exacerbating neural oscillations associated with inattention and cognitive deficits. PMID:22681691

The frequency of asthma exacerbations and healthcare utilization in patients with asthma from the UK and USA.

PubMed

Suruki, Robert Y; Daugherty, Jonas B; Boudiaf, Nada; Albers, Frank C

2017-04-27

Asthma exacerbations are frequent in patients with severe disease. This report describes results from two retrospective cohort studies describing exacerbation frequency and risk, emergency department (ED)/hospital re-admissions, and asthma-related costs by asthma severity in the US and UK. Patients with asthma in the US-based Clinformatics™ DataMart Multiplan IMPACT (2010-2011; WEUSKOP7048) and the UK-based Clinical Practice Research Datalink (2009-2011; WEUSKOP7092) databases were categorized by disease severity (Global Initiative for Asthma [GINA]; Step and exacerbation history) during the 12 months pre-asthma medical code (index date). Outcomes included: frequency of exacerbations (asthma-related ED visit, hospitalization, or oral corticosteroid use with an asthma medical code recorded within ±2 weeks) 12 months post-index, asthma-related ED visits/hospitalization, and asthma-related costs 30 days post-index. Risk of a subsequent exacerbation was determined by proportional hazard model. Of the 222,817 and 211,807 patients with asthma included from the US and UK databases, respectively, 12.5 and 8.4% experienced ≥1 exacerbation during the follow-up period. Exacerbation frequency increased with disease severity. Among the 5,167 and 2,904 patients with an asthma-related ED visit/hospitalization in the US and UK databases, respectively, 9.2 and 4.7% had asthma-related re-admissions within 30 days. Asthma-related re-admission rates and costs increased with disease severity, approximately doubling between GINA Step 1 and 5 and in patients with ≥2 versus <2 exacerbations in the previous year. Risk of a subsequent exacerbation increased 32-35% for an exacerbation requiring ED visit/hospitalization versus oral corticosteroids. Increased disease severity was associated with higher exacerbation frequency, ED/hospitalization re-admission, costs and risk of subsequent exacerbation, indicating that these patients require high-intensity post-exacerbation management.

Inflammatory bowel disease exacerbation associated with Epstein-Barr virus infection.

PubMed

Dimitroulia, Evangelia; Pitiriga, Vassiliki C; Piperaki, Evangelia-Theophano; Spanakis, Nicholas E; Tsakris, Athanassios

2013-03-01

Epstein-Barr virus infection is associated with inflammatory bowel disease, but its role as a pathogenetic or exacerbating factor remains unclear. The aim of this study was to evaluate the association between Epstein-Barr virus infection and inflammatory bowel disease, particularly in regard to exacerbation of disease activity. This was a nonrandomized crosssectional study in subgroups of patients with inflammatory bowel disease compared with a control group with noninflammatory disease. Participants were patients treated for ulcerative colitis or Crohn's disease and individuals undergoing evaluation for noninflammatory disease recruited from 2 urban adult gastrointestinal referral centers in Greece. Diagnosis of inflammatory bowel disease was based on standard clinical and endoscopic criteria. Demographic and clinical characteristics of all participants were recorded. Whole blood samples and fresh tissue samples from biopsy of intestinal sites were obtained from each participant. The presence of Epstein-Barr virus was determined by amplifying the LMP1 gene of the virus in blood and intestinal tissue samples. The study comprised 94 patients with inflammatory bowel disease (63 with ulcerative colitis and 31 with Crohn's disease) and 45 controls with noninflammatory disease. Of the 94 patients, 67 (71.3%) had disease exacerbation and 27 (28.7%) were in remission. The prevalence of Epstein-Barr virus genome was significantly higher in patients than in controls for intestinal tissue (44 patients, 46.8% vs 6 controls, 13.3%; p = 0.001), but not for whole blood (24 patients, 25.5% vs 9 controls, 20%; p = 0.3). The viral genome was found significantly more frequently in intestinal samples from patients with disease exacerbation compared with patients in remission (38 patients with exacerbation, 56.7% vs 6 patients in remission, 22.2%; p = 0.001), but no significant difference was found for whole blood (18 patients with exacerbation, 26.8% vs 6 patients in remission, 22.2%; p = 0.79). Neither disease exacerbation nor the presence of virus genome was related to demographic or clinical characteristics. The exact location of Epstein-Barr virus in the intestinal tissues could not be specified because morphological data by immunohistochemistry or in situ hybridization were not available. Although causality could not be determined, the significantly higher prevalence of Epstein-Barr virus in intestinal tissue from patients with inflammatory bowel disease compared with controls and in patients with exacerbation compared with patients in remission suggests a potential viral involvement in the severity of inflammatory bowel disease. These findings merit further investigation in view of a potential for usefulness of antiviral therapy against Epstein-Barr virus infection in patients with exacerbation of inflammatory bowel disease.

Cloning, sequence, and expression of a blood group B active recombinant alpha-D-galactosidase from pinto bean (Phaseolus vulgaris).

PubMed

Davis, M O; Hata, D J; Johnson, S A; Jones, D E; Harmata, M A; Evans, M L; Walker, J C; Smith, D S

1997-07-01

A cDNA encoding pinto bean alpha-D-galactosidase [E.C. 3.2.1.22] was obtained by amplification of cDNA using highly conserved sequences found in eucaryotic alpha-D-galactosidases. Subsequently a full length Phaseolus cDNA clone was obtained that is 1537 nt long and contains untranslated 5' and 3' sequences. The nucleotide sequence of the cDNA has a high degree of homology with other eucaryotic alpha-D-galactosidase genes. The recombinant alpha-D-galactosidase (rGal) was expressed in Escherichia coli and purified by ion exchange and affinity chromatography. Purified rGal was homogeneous by SDS-PAGE and had relative masses of 40.1 and 45.4 kDa under nonreducing and reducing conditions, respectively. The N-terminal sequence of the expressed protein contained the sequence GNGLGQTPPMG corresponding to that deduced from the cDNA sequence. The native molecular weight for rGal was determined to be 32.18 kDa by Sephacryl S-200 chromatography. The specific activity of the rGal was 349 mu moles of PNP-alpha-D-galactopyranoside hydrolyzed per mg of pure rGal per min. rGal was highly specific for alpha-D-galactosyl residues and degraded B oligosaccharide. No detectable hemagglutinin or protease activity was present in the preparations. Furthermore, rGal was active against the blood group B antigen on native human erythrocytes in cell suspension assays. The only detectable RBC phenotypic change was loss of the B and P1 epitopes. Recombinant Phaseolus vulgaris alpha-D-galactosidase may have useful biotechnical applications in the potential mass production of enzymatically converted, universally transfusable type O RBCs. alpha-D-galactosidase [E.C. 3.2.1.22] has been purified from a variety of procaryotic and eucaryotic species. Most alpha-D-galactosidases have similar low molecular weight substrate specificities, but activity against high molecular weight substrates is variable. Terminal alpha-D-galactoside residues are present in glycoproteins and glycolipids. Some alpha-D-galactosidases have activity against alpha-D-galactosyl residues on cell membrane glycoconjugates. Glycosidases with this property are useful for carbohydrate structural studies and biotechnical applications. Enzymes free of other glycosidase activities with activity near neutral pH are particularly useful for membrane modification studies on native cells. Complex sugar chains in glycolipids and glycoproteins have often been implicated in the growth and development of eucaryotes. In particular, complex sugar chains play an important role in the recognition of self in the immune system. Some alpha-D-galactosidases can modify certain carbohydrate membrane epitopes, thereby modulating the immune response. For example, the blood group B epitope expressed on erythrocytes contains a terminal alpha-D-galactosyl residue. Individuals lacking this antigen produce naturally occurring complement fixing antibodies to the B epitope. Hydrolysis of this terminal saccharide destroys the antigenic activity of the B determinant producing H antigen (blood type O) on erythrocytes. Only rare individuals produce clinically significant antibodies to the H antigen, and therefore, type O red blood cells are "universally" compatible and in great demand. Dhar purified alpha-D-galactosidase isozymes from Phaseolus vulgaris and characterized their activity. To our knowledge, our laboratory, in a brief report, is the first to describe the cloning of the gene and the use of recombinant enzyme for seroconverting blood type B to O cells. This paper describes the cloning, sequence, expression, purification, and characterization of recombinant alpha-D-galactosidase. Activity of the recombinant enzyme on the native human erythrocyte blood group B epitope is shown.

Icilin-evoked behavioral stimulation is attenuated by alpha2-adrenoceptor activation

PubMed Central

Kim, Jae; Cowan, Alan; Lisek, Renata; Raymondi, Natalie; Rosenthal, Aaron; Hirsch, Daniel D.; Rawls, Scott M.

2011-01-01

Icilin is a transient receptor potential cation channel subfamily M (TRPM8) agonist that produces behavioral activation in rats and mice. Its hallmark overt pharmacological effect is wet-dog shakes (WDS) in rats. The vigorous shaking associated with icilin is dependent on NMDA receptor activation and nitric oxide production, but little else is known about the biological systems that modulate the behavioral phenomenon. The present study investigated the hypothesis that alpha2-adrenoceptor activation inhibits icilin-induced WDS. Rats injected with icilin (0.5, 1, 2.5, 5 mg/kg, i.p.) displayed dose-related WDS that were inhibited by pretreatment with a fixed dose of clonidine (0.15 mg/kg, s.c.). Shaking behavior caused by a fixed dose (2.5 mg/kg) of icilin was also inhibited in a dose-related manner by clonidine pretreatment (0.03–0.15 mg/kg, s.c.) and reduced by clonidine posttreatment (0.15 mg/kg, s.c.). Pretreatment with a peripherally restricted alpha2-adrenoceptor agonist, ST91 (0.075, 0.15 mg/kg), also decreased the incidence of shaking elicited by 2.5 mg/kg of icilin. Pretreatment with yohimbine (2 mg/kg, i.p.) enhanced the shaking induced by a low dose of icilin (0.5 mg/kg). The imidazoline site agonists, agmatine (150 mg/kg, i.p.) and 2-BFI (7 mg/kg, i.p.), did not affect icilin-evoked shaking. These results suggest that alpha2-adrenoceptor activation inhibits shaking induced by icilin and that increases in peripheral, as well as central, alpha2-adrenoceptor signaling oppose the behavioral stimulant effect of icilin. PMID:21315691

The Val{sup 192}Leu mutation in the {alpha}-subunit of {beta}-hexosaminidase A is not associated with the B1-variant form of Tay-Sachs disease

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

Hou, Y.; Vavougios, G.; Hinek, A.

1996-07-01

Substitution mutations adversely affecting the {alpha}-subunit of {beta}-hexosaminidase A ({alpha}{beta}) (EC 3.2.1.52) result in Tay-Sachs disease. The majority affect the initial folding of the pro-{alpha} chain in the endoplasmic reticulum, resulting in its retention and degradation. A much less common occurrence is a mutation that specifically affects an {open_quotes}active-site{close_quotes} residue necessary for substrate binding and/or catalysis. In this case, hexosaminidase A is present in the lysosome, but it lacks all {alpha}-specific activity. This biochemical phenotype is referred to as the {open_quotes}B1-variant form{close_quotes} of Tay-Sachs disease. Kinetic analysis of suspected B1-variant mutations is complex because hexosaminidase A is heterodimeric and bothmore » subunits possess similar active sites. In this report, we examine a previously identified B1-variant mutation, {alpha}-Val{sup 192}Leu. Chinese hamster ovary cells were permanently cotransfected with an {alpha}-cDNA-construct encoding the substitution and a mutant {beta}-cDNA ({beta}-Arg{sup 211}Lys), encoding a {beta}-subunit that is inactive but normal in all other respects. We were surprised to find that the Val{sup 192}Leu substitution produced a pro-{alpha} chain that did not form {alpha}-{beta} dimers and was not transported to the lysosome. Finally, we reexamined the hexosaminidase activity and protein levels in the fibroblasts from the original patient. These data were also not consistent with the biochemical phenotype of the B1 variant of Tay-Sachs disease previously reported to be present. Thus, we conclude that the Val{sup 192}Leu substitution does not specifically affect the {alpha}-active site. 23 refs., 4 figs., 2 tabs.« less

Induced expression of mRNA for IL-5, IL-6, TNF-alpha, MIP-2 and IFN-gamma in immunologically activated rat peritoneal mast cells: inhibition by dexamethasone and cyclosporin A.

PubMed Central

Williams, C M; Coleman, J W

1995-01-01

We examined the capacity of purified rat peritoneal connective tissue-type mast cells (PMC) to express mRNA for several cytokines. Stimulation of PMC with anti-IgE for 4 hr induced the expression of mRNA encoding interleukin-5 (IL-5), IL-6, tumour necrosis factor-alpha (TNF-alpha), macrophage inflammatory protein-2 (MIP-2) and interferon-gamma (IFN-gamma). Unstimulated PMC expressed detectable mRNA for TNF-alpha but not for the other four cytokines. Incubation of PMC with cyclosporin A (CsA) or dexamethasone (DEX), each at 10(-6) M for 24 hr, significantly inhibited the induced expression of mRNA for each of the five cytokines, and also inhibited release of biologically active TNF-alpha. Throughout these experiments mRNA levels of the housekeeping gene G3PDH were not altered by stimulation with anti-IgE or incubation with CsA or DEX. We conclude that immunological activation of rat PMC induces gene expression of several cytokines and that expression of these genes can be inhibited by immunosuppressive drugs. Images Figure 1 Figure 2 Figure 3 PMID:7490125

Potential antiradical and alpha-glucosidase inhibitors from Ecklonia maxima (Osbeck) Papenfuss.

PubMed

Rengasamy, Kannan R R; Aderogba, Mutalib A; Amoo, Stephen O; Stirk, Wendy A; Van Staden, Johannes

2013-11-15

Alpha-glucosidase inhibitors play a potential role in the treatment of type 2 diabetes by delaying glucose absorption in the small intestine. Ecklonia maxima, a brown alga which grows abundantly on the west coast of South Africa, is used to produce alginate, animal feed, nutritional supplements and fertilizer. The crude aqueous methanol extract, four solvent fractions and three phlorotannins: 1,3,5-trihydroxybenezene (phloroglucinol) (1), dibenzo [1,4] dioxine-2,4,7,9-tetraol (2) and hexahydroxyphenoxydibenzo [1,4] dioxine (eckol) (3) isolated from E. maxima were evaluated for antiradical and alpha-glucosidase inhibitory activities. All the phlorotannins tested had strong antioxidant activities on DPPH free radicals with EC50 values ranging from 0.008 to 0.128μM. Compounds 2 and 3 demonstrated stronger antioxidant activity and an alpha-glucosidase inhibitory property than positive controls. These results suggest that E. maxima could be a natural source of potent antioxidants and alpha-glucosidase inhibitors. This study could facilitate effective utilization of E. maxima as an oral antidiabetic drug or functional food ingredient with a promising role in the formulation of medicines and nutrition supplements. Copyright © 2013 Elsevier Ltd. All rights reserved.

Hemolytic activity of Fusobacterium necrophorum culture supernatants due to presence of phospholipase A and lysophospholipase.

PubMed

Abe, P M; Kendall, C J; Stauffer, L R; Holland, J W

1979-01-01

Culture supernatants of Fusobacterium necrophorum demonstrated hemolytic activity. The hemolysin(s), which was partially purified by ammonium sulfate precipitation, was temperature-dependent and heat labile. The spectrum of hemolytic activity against various erythrocytes included rabbit, human, and dog erythrocytes. Goats, sheep, and bovine erythrocytes showed only trace hemolysis. According to results of thin-layer chromatography, the hemolysin hydrolyzed rabbit erythrocyte phosphatidyl choline, phosphatidyl ethanolamine, lysophosphatidyl choline, and bovine phosphatidyl choline. Hydrolysis of egg yolk phosphatidyl choline, bovine phosphatidyl ethanolamine, cholesterol, 1,2-dipalmitin, 1,3-dipalmitin, sphingomyelin, or triolein was not detected by thin layer chromatography. A more sensitive procedure utilizing gas-liquid chromatography revealed that, of the substrates tested, the following were bein hydrolyzed: bovine and egg yolk phosphatidyl choline, lysophosphatidyl choline, alpha-palmito-beta-eleoyl-L-alpha lecithin and alpha-oleoyl-betal-palmitoyl-L-alpha lecithin. Substrates which were weakly hydrolyzed were bovine phosphatidyl ethanolamine, DL-alpha-hosphatidyl ethanolamine dipalmitoyl, 1,2-dipalmitin, 1,3-dipalmitin, and triolein.

Structural Basis for Hormone Recognition by the Human CRFR2[alpha] G Protein-coupled Receptor

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

Pal, Kuntal; Swaminathan, Kunchithapadam; Xu, H. Eric

2012-05-09

The mammalian corticotropin releasing factor (CRF)/urocortin (Ucn) peptide hormones include four structurally similar peptides, CRF, Ucn1, Ucn2, and Ucn3, that regulate stress responses, metabolism, and cardiovascular function by activating either of two related class B G protein-coupled receptors, CRFR1 and CRFR2. CRF and Ucn1 activate both receptors, whereas Ucn2 and Ucn3 are CRFR2-selective. The molecular basis for selectivity is unclear. Here, we show that the purified N-terminal extracellular domains (ECDs) of human CRFR1 and the CRFR2{alpha} isoform are sufficient to discriminate the peptides, and we present three crystal structures of the CRFR2{alpha} ECD bound to each of the Ucn peptides.more » The CRFR2{alpha} ECD forms the same fold observed for the CRFR1 and mouse CRFR2{beta} ECDs but contains a unique N-terminal {alpha}-helix formed by its pseudo signal peptide. The CRFR2{alpha} ECD peptide-binding site architecture is similar to that of CRFR1, and binding of the {alpha}-helical Ucn peptides closely resembles CRF binding to CRFR1. Comparing the electrostatic surface potentials of the ECDs suggests a charge compatibility mechanism for ligand discrimination involving a single amino acid difference in the receptors (CRFR1 Glu104/CRFR2{alpha} Pro-100) at a site proximate to peptide residue 35 (Arg in CRF/Ucn1, Ala in Ucn2/3). CRFR1 Glu-104 acts as a selectivity filter preventing Ucn2/3 binding because the nonpolar Ala-35 is incompatible with the negatively charged Glu-104. The structures explain the mechanisms of ligand recognition and discrimination and provide a molecular template for the rational design of therapeutic agents selectively targeting these receptors.« less

The alpha(2a)-adrenergic receptor plays a protective role in mouse behavioral models of depression and anxiety.

PubMed

Schramm, N L; McDonald, M P; Limbird, L E

2001-07-01

The noradrenergic system is involved in the regulation of many physiological and psychological processes, including the modulation of mood. The alpha(2)-adrenergic receptors (alpha(2)-ARs) modulate norepinephrine release, as well as the release of serotonin and other neurotransmitters, and are therefore potential targets for antidepressant and anxiolytic drug development. The current studies were undertaken to examine the role of the alpha(2A) subtype of alpha(2)-AR in mouse behavioral models of depression and anxiety. We have observed that the genetic knock-out of the alpha(2A)-AR makes mice less active in a modified version of Porsolt's forced swim test and insensitive to the antidepressant effects of the tricyclic drug imipramine in this paradigm. Furthermore, alpha(2A)-AR knock-out mice appear more anxious than wild-type C57 Bl/6 mice in the rearing and light-dark models of anxiety after injection stress. These findings suggest that the alpha(2A)-AR may play a protective role in some forms of depression and anxiety and that the antidepressant effects of imipramine may be mediated by the alpha(2A)-AR.

Analysis of the specificity of sialyltransferases toward mucin core 2, globo, and related structures. identification of the sialylation sequence and the effects of sulfate, fucose, methyl, and fluoro substituents of the carbohydrate chain in the biosynthesis of selectin and siglec ligands, and novel sialylation by cloned alpha2,3(O)sialyltransferase.

PubMed

Chandrasekaran, E V; Xue, Jun; Xia, Jie; Chawda, Ram; Piskorz, Conrad; Locke, Robert D; Neelamegham, Sriram; Matta, Khushi L

2005-11-29

Sialic acids are key determinants in many carbohydrates involved in biological recognition. We studied the acceptor specificities of three cloned sialyltransferases (STs) [alpha2,3(N)ST, alpha2,3(O)ST, and alpha2,6(N)ST] and another alpha2,3(O)ST present in prostate cancer cell LNCaP toward mucin core 2 tetrasaccharide [Galbeta1,4GlcNAcbeta1,6(Galbeta1,3)GalNAcalpha-O-Bn] and Globo [Galbeta1,3GalNAcbeta1,3Galalpha-O-Me] structures containing sialyl, fucosyl, sulfo, methyl, or fluoro substituents by identifying the products by electrospray ionization tandem mass spectral analysis and other biochemical methods. The Globo precursor was an efficient acceptor for both alpha2,3(N)ST and alpha2,3(O)ST, whereas only alpha2,3(O)ST used its deoxy analogue (d-Fucbeta1,3GalNAcbeta1,3-Gal-alpha-O-Me); 2-O-MeGalbeta1,3GlcNAc and 4-OMeGalbeta1,4GlcNAc were specific acceptors for alpha2,3(N)ST. Other major findings of this study include: (i) alpha2,3 sialylation of beta1,3Gal in mucin core 2 can proceed even after alpha1,3 fucosylation of beta1,6-linked LacNAc. (ii) Sialylation of beta1,3Gal must precede the sialylation of beta1,4Gal for favorable biosynthesis of mucin core 2 compounds. (iii) alpha2,3 sialylation of the 6-O-sulfoLacNAc moiety in mucin core 2 (e.g., GlyCAM-1) is facilitated when beta1,3Gal has already been alpha2,3 sialylated. (iv) alpha2,6(N)ST was absolutely specific for the beta1,4Gal in mucin core 2. Either alpha1,3 fucosylation or 6-O-sulfation of the GlcNAc moiety reduced the activity. Sialylation of beta1,3Gal in addition to 6-O-sulfation of GlcNAc moiety abolished the activity. (v) Prior alpha2,3 sialylation or 3-O-sulfation of beta1,3Gal would not affect alpha2,6 sialylation of Galbeta1,4GlcNAc of mucin core 2. (vi) A 3- or 4-fluoro substituent in beta1,4Gal resulted in poor acceptors for the cloned alpha2,6(N)ST and alpha2,3(N)ST, whereas 4-fluoro- or 4-OMe-Galbeta1,3GalNAcalpha was a good acceptor for cloned alpha2,3(O)ST. (vii) 4-O-Methylation of beta1,4Gal abolished the acceptor ability toward alpha2,6(N)ST but increased the acceptor efficiency considerably toward alpha2,3(N)ST. (viii) Just like LNCaPalpha1,2-FT and Gal-3-O-sulfotransferase T2, the cloned alpha2,3(N)ST which modifies terminal Gal in Galbeta1,4GlcNAc also efficiently utilizes the terminal beta1,3Gal in the Globo backbone. Utilization of C-3 blocked compounds such as 3-O-sulfo-Galbeta1,3GalNAcbeta1,3Galalpha-OMe as acceptors by cloned alpha2,3(O)ST and analyses of the resulting products by lectin chromatography and mass spectrometry indicate that alpha2,3(O)ST is capable of attaching NeuAc to another position in C-3-substituted beta1,3Gal.

Constituents of Senecio chionophilus with potential antitubercular activity.

PubMed

Gu, Jian-Qiao; Wang, Yuehong; Franzblau, Scott G; Montenegro, Gloria; Timmermann, Barbara N

2004-09-01

Two new sesquiterpenoids, (1S,4S,5R,10R)-1-hydroxy-6-isobutyryloxy-10H-9-oxofuranoeremophilane (1) and 1alpha-hydroxy-6beta-(2xi-methylbutyryloxy)-10alphaH-9-oxofuranoeremophilane (2), along with 21 known constituents, were isolated from the n-hexane and dichloromethane extracts of the above-ground biomass and roots of Senecio chionophilus. The structures of 1 and 2 were elucidated on the basis of spectroscopic evidence and chemical transformation methods. The absolute configuration of 1 was determined by Mosher ester methodology. All of the isolates were evaluated for their antitubercular potential against Mycobacterium tuberculosis in a microplate Alamar Blue assay. Compound 2, 6beta-angeloyloxy-1alpha-hydroxy-10alphaH-9-oxofuranoeremophilane (3), and 4'-hydroxyacetophenone (6) exhibited mild antitubercular activity at minimum inhibitory concentrations of 119, 114, and 121 microg/mL, respectively.

The effect of Al2O3, CaO, Cr2O3 and MgO on devitrification of silica

NASA Technical Reports Server (NTRS)

Zaplatynsky, Isidor

1988-01-01

The effect of doping on devitrification of vitreous silica was studied at 1100, 1200, and 1300 C. Dispersion of dopants on a molecular scale was accomplished via a sol-gel technique. All dopants accelerated the devitrification of silica but to different degrees. The most active was CaO followed by MgO, Al2O3, and Cr2O3. Pure silica and silica containing Cr2O3 and Al2O3 devitrified to alpha-cristobalite only, whereas silica doped with CaO and MgO produced alpha-quartz and alpha-cristobalite. It appears that prolonged heat treatment would cause alpha-quartz to transform to alpha-cristobalite.

Discovery of Ecopladib, an indole inhibitor of cytosolic phospholipase A2alpha.

PubMed

Lee, Katherine L; Foley, Megan A; Chen, Lihren; Behnke, Mark L; Lovering, Frank E; Kirincich, Steven J; Wang, Weiheng; Shim, Jaechul; Tam, Steve; Shen, Marina W H; Khor, Soopeang; Xu, Xin; Goodwin, Debra G; Ramarao, Manjunath K; Nickerson-Nutter, Cheryl; Donahue, Frances; Ku, M Sherry; Clark, James D; McKew, John C

2007-03-22

The synthesis and structure-activity relationship of a series of indole inhibitors of cytosolic phospholipase A2alpha (cPLA2alpha, type IVA phospholipase) are described. Inhibitors of cPLA2alpha are predicted to be efficacious in treating asthma as well as the signs and symptoms of osteoarthritis, rheumatoid arthritis, and pain. The introduction of a benzyl sulfonamide substituent at C2 was found to impart improved potency of these inhibitors, and the SAR of these sulfonamide analogues is disclosed. Compound 123 (Ecopladib) is a sub-micromolar inhibitor of cPLA2alpha in the GLU micelle and rat whole blood assays. Compound 123 displayed oral efficacy in the rat carrageenan air pouch and rat carrageenan-induced paw edema models.

Autism-Like Behaviours and Memory Deficits Result from a Western Diet in Mice.

PubMed

Veniaminova, Ekaterina; Cespuglio, Raymond; Cheung, Chi Wai; Umriukhin, Alexei; Markova, Nataliia; Shevtsova, Elena; Lesch, Klaus-Peter; Anthony, Daniel C; Strekalova, Tatyana

2017-01-01

Nonalcoholic fatty liver disease, induced by a Western diet (WD), evokes central and peripheral inflammation that is accompanied by altered emotionality. These changes can be associated with abnormalities in social behaviour, hippocampus-dependent cognitive functions, and metabolism. Female C57BL/6J mice were fed with a regular chow or with a WD containing 0.2% of cholesterol and 21% of saturated fat for three weeks. WD-treated mice exhibited increased social avoidance, crawl-over and digging behaviours, decreased body-body contacts, and hyperlocomotion. The WD-fed group also displayed deficits in hippocampal-dependent performance such as contextual memory in a fear conditioning and pellet displacement paradigms. A reduction in glucose tolerance and elevated levels of serum cholesterol and leptin were also associated with the WD. The peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PPARGC1a) mRNA, a marker of mitochondrial activity, was decreased in the prefrontal cortex, hippocampus, hypothalamus, and dorsal raphe, suggesting suppressed brain mitochondrial functions, but not in the liver. This is the first report to show that a WD can profoundly suppress social interactions and induce dominant-like behaviours in naïve adult mice. The spectrum of behaviours that were found to be induced are reminiscent of symptoms associated with autism, and, if paralleled in humans, suggest that a WD might exacerbate autism spectrum disorder.

Autism-Like Behaviours and Memory Deficits Result from a Western Diet in Mice

PubMed Central

Cespuglio, Raymond; Umriukhin, Alexei

2017-01-01

Nonalcoholic fatty liver disease, induced by a Western diet (WD), evokes central and peripheral inflammation that is accompanied by altered emotionality. These changes can be associated with abnormalities in social behaviour, hippocampus-dependent cognitive functions, and metabolism. Female C57BL/6J mice were fed with a regular chow or with a WD containing 0.2% of cholesterol and 21% of saturated fat for three weeks. WD-treated mice exhibited increased social avoidance, crawl-over and digging behaviours, decreased body-body contacts, and hyperlocomotion. The WD-fed group also displayed deficits in hippocampal-dependent performance such as contextual memory in a fear conditioning and pellet displacement paradigms. A reduction in glucose tolerance and elevated levels of serum cholesterol and leptin were also associated with the WD. The peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PPARGC1a) mRNA, a marker of mitochondrial activity, was decreased in the prefrontal cortex, hippocampus, hypothalamus, and dorsal raphe, suggesting suppressed brain mitochondrial functions, but not in the liver. This is the first report to show that a WD can profoundly suppress social interactions and induce dominant-like behaviours in naïve adult mice. The spectrum of behaviours that were found to be induced are reminiscent of symptoms associated with autism, and, if paralleled in humans, suggest that a WD might exacerbate autism spectrum disorder. PMID:28685102

Tumor necrosis factor-alpha activates signal transduction in hypothalamus and modulates the expression of pro-inflammatory proteins and orexigenic/anorexigenic neurotransmitters.

PubMed

Amaral, Maria E; Barbuio, Raquel; Milanski, Marciane; Romanatto, Talita; Barbosa, Helena C; Nadruz, Wilson; Bertolo, Manoel B; Boschero, Antonio C; Saad, Mario J A; Franchini, Kleber G; Velloso, Licio A

2006-07-01

Tumor necrosis factor-alpha (TNF-alpha) is known to participate in the wastage syndrome that accompanies cancer and severe infectious diseases. More recently, a role for TNF-alpha in the pathogenesis of type 2 diabetes mellitus and obesity has been shown. Much of the regulatory action exerted by TNF-alpha upon the control of energy stores depends on its action on the hypothalamus. In this study, we show that TNF-alpha activates canonical pro-inflammatory signal transduction pathways in the hypothalamus of rats. These signaling events lead to the transcriptional activation of an early responsive gene and to the induction of expression of cytokines and a cytokine responsive protein such as interleukin-1beta, interleukin-6, interleukin-10 and suppressor of cytokine signalling-3, respectively. In addition, TNF-alpha induces the expression of neurotransmitters involved in the control of feeding and thermogenesis. Thus, TNF-alpha may act directly in the hypothalamus inducing a pro-inflammatory response and the modulation of expression of neurotransmitters involved in energy homeostasis.

An immunocapture/scintillation proximity analysis of G alpha q/11 activation by native serotonin (5-HT)2A receptors in rat cortex: blockade by clozapine and mirtazapine.

PubMed

Mannoury La Cour, C; Chaput, C; Touzard, M; Millan, M J

2009-02-01

Though transduction mechanisms recruited by heterologously expressed 5-HT(2A) receptors have been extensively studied, their interaction with specific subtypes of G-protein remains to be directly evaluated in cerebral tissue. Herein, as shown by an immunocapture/scintillation proximity analysis, 5-HT, the prototypical 5-HT(2A) agonist, DOI, and Ro60,0175 all enhanced [(35)S]GTPgammaS binding to G alpha q/11 in rat cortex with pEC(50) values of 6.22, 7.24 and 6.35, respectively. No activation of G o or G s/olf was seen at equivalent concentrations of DOI. Stimulation of G alpha q/11 by 5-HT (30 microM) and DOI (30 microM) was abolished by the selective 5-HT(2A) vs. 5-HT(2C)/5-HT(2B) antagonists, ketanserin (pK(B) values of 9.11 and 8.88, respectively) and MDL100,907 (9.82 and 9.68). By contrast, 5-HT-induced [(35)S]GTPgammaS binding to G alpha q/11 was only weakly inhibited by the preferential 5-HT(2C) receptor antagonists, RS102,221 (6.94) and SB242,084 (7.39), and the preferential 5-HT(2B) receptor antagonist, LY266,097 (6.66). The antipsychotic, clozapine, which had marked affinity for 5-HT(2A) receptors, blocked the recruitment of G alpha q/11 by 5-HT and DOI with pK(B) values of 8.54 and 8.14, respectively. Its actions were mimicked by the "atypical" antidepressant and 5-HT(2A) receptor antagonist, mirtazapine, which likewise blocked 5-HT and DOI-induced G alpha q/11 protein activation with pK(B) values of 7.90 and 7.76, respectively. In conclusion, by use of an immunocapture/scintillation proximity strategy, this study shows that native 5-HT(2A) receptors in rat frontal cortex specifically recruit G alpha q/11 and that this action is blocked by clozapine and mirtazapine. Quantification of 5-HT(2A) receptor-mediated G alpha q/11 activation in frontal cortex should prove instructive in characterizing the actions of diverse classes of psychotropic agent. 2008 Wiley-Liss, Inc.

Activation of the serotonergic system by pedaling exercise changes anterior cingulate cortex activity and improves negative emotion.

PubMed

Ohmatsu, Satoko; Nakano, Hideki; Tominaga, Takanori; Terakawa, Yuzo; Murata, Takaho; Morioka, Shu

2014-08-15

Pedaling exercise (PE) of moderate intensity has been shown to ease anxiety and discomfort; however, little is known of the changes that occur in brain activities and in the serotonergic (5-HT) system after PE. Therefore, this study was conducted for the following reasons: (1) to localize the changes in the brain activities induced by PE using a distributed source localization algorithm, (2) to examine the changes in frontal asymmetry, as used in the Davidson model, with electroencephalography (EEG) activity, and (3) to examine the effect of PE on the 5-HT system. A 32-channel EEG was used to record before and after PE. Profile of Mood States tests indicated that there was a significant decrease in tension-anxiety and a significant increase in vigor after PE. A standardized low-resolution brain electromagnetic tomography analysis showed a significant decrease in brain activities after PE in the alpha-2 band (10-12.5 Hz) in the anterior cingulate cortex (ACC). Moreover, a significant increase in frontal EEG asymmetry was observed after PE in the alpha-1 band (7.5-10 Hz). Urine 5-HT levels significantly increased after PE. Urine 5-HT levels positively correlated with the degree of frontal EEG asymmetry in the alpha-1 band and negatively correlated with brain activity in ACC. Our results suggested that PE activates the 5-HT system and consequently induces increases in frontal EEG asymmetry in the alpha-1 band and reductions of brain activity in the alpha-2 band in the ACC region. Copyright © 2014 Elsevier B.V. All rights reserved.

Triterpene glycosides from the tubers of Anemone coronaria.

PubMed

Mimaki, Yoshihiro; Watanabe, Kazuki; Matsuo, Yukiko; Sakagami, Hiroshi

2009-07-01

Six new triterpene glycosides (1-6), together with 11 known ones (7-17), have been isolated from a glycoside-enriched fraction prepared from the tubers of Anemone coronaria L. (Ranunculaceae). On the basis of extensive spectroscopic analysis, including 2D NMR data, and the results of hydrolytic cleavage, the structures of 1-6 were determined to be 3beta-[(O-beta-D-glucopyranosyl-(1-->4)-O-[alpha-L-rhamnopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl)oxy]-2beta,23-dihydroxyolean-12-en-28-oic acid (1), 3beta-[(O-beta-D-glucopyranosyl-(1-->3)-O-alpha-L-rhamnopyranosyl-(1-->2)-O-[beta-D-glucopyranosyl-(1-->4)]-alpha-L-arabinopyranosyl)oxy]-23-hydroxyolean-12-en-28-oic acid (2), 3beta-[(O-beta-D-glucopyranosyl-(1-->4)-O-[alpha-L-rhamnopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl)oxy]-23-hydroxyolean-12-en-28-oic acid O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester (3), 3beta-[(O-beta-D-glucopyranosyl-(1-->4)-O-[alpha-L-rhamnopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl)oxy]-2beta,23-dihydroxyolean-12-en-28-oic acid O-alpha-L-rhamnopyranosyl-(1-->4)-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester (4), 3beta-[(O-beta-D-glucopyranosyl-(1-->4)-O-[alpha-L-rhamnopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl)oxy]-2beta-hydroxyolean-12-en-28-oic acid O-alpha-L-rhamnopyranosyl-(1-->4)-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester (5), and 3beta-[(O-beta-D-glucopyranosyl-(1-->4)-O-[alpha-L-rhamnopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl)oxy]-23-hydroxyolean-18-en-28-oic acid O-alpha-L-rhamnopyranosyl-(1-->4)-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester (6), respectively. Furthermore, the isolated compounds were evaluated for their cytotoxic activity against HSC-2 cells.

Induction of autocrine factor inhibiting cell motility from murine B16-BL6 melanoma cells by alpha-melanocyte stimulating hormone.

PubMed

Murata, J; Ayukawa, K; Ogasawara, M; Watanabe, H; Saiki, I

1999-03-15

We have previously reported that neuropeptide alpha-melanocyte stimulating hormone (alpha-MSH) successfully inhibited Matrigel invasion and haptotactic migration of B16-BL6 melanoma cells towards both fibronectin and laminin without affecting their growth. In the present study, we investigated the inhibitory mechanism of tumor cell motility by alpha-MSH. Alpha-MSH significantly blocked the autocrine motility factor (AMF)-enhanced cell motility. However, alpha-MSH did neither prevent the secretion of AMF from B16-BL6 cells nor alter the expression level of AMF receptor (gp78). On the other hand, alpha-MSH induced the secretion of the motility inhibitory factor(s) from B16-BL6 cells in a concentration- and time-dependent manner. The induction of the motility inhibitor(s) was proportional to increasing levels of intracellular cAMP induced by alpha-MSH as well as forskolin, and the activity was abolished by an adenylate cyclase inhibitor, 2',5'-dideoxyadenosine (DDA). The motility-inhibiting activity in conditioned medium (CM) from alpha-MSH-treated B16-BL6 cells was found to have a m.w. below 3 kDa after fractionation. This activity was abolished by boiling but insensitive to trypsin. The treatment of tumor cells with cycloheximide reduced the activity in alpha-MSH-stimulated CM. Our results suggest that alpha-MSH inhibited the motility of B16-BL6 cells through induction of autocrine factor(s).

Structural characterization of novel L-galactose-containing oligosaccharide subunits of jojoba seed xyloglucans.

PubMed

Hantus, S; Pauly, M; Darvill, A G; Albersheim, P; York, W S

1997-10-28

Jojoba seed xyloglucan was shown to be a convenient source of biologically active xyloglucan oligosaccharides that contain both L- and D-galactosyl residues [E. Zablackis et al., Science, 272 (1996) 1808-1810]. Oligosaccharides were isolated by liquid chromatography of the mixture of oligosaccharides generated by treating jojoba seed xyloglucan with a beta-(1-->4)-endoglucanase. The purified oligosaccharides were reduced with NaBH4, converting them to oligoglycosyl alditol derivatives that were structurally characterized by a combination of mass spectrometry and 2-dimensional NMR spectroscopy. This analysis established that jojoba xyloglucan oligosaccharides contain the novel side-chain [alpha-L-Gal p-(1-->2)-beta-D-Galp-(1-->2)-alpha-D-Xyl p-(1-->6)-], which is structurally homologous to the fucose-containing side-chain [alpha-L-Fucp-(1-->2)-beta-D-Galp-(1-->2)-alpha-D-Xyl p-(1-->6)-] found in other biologically active xyloglucan oligosaccharides.

Characterization of the primary interaction between the mating pheromone, alpha-factor, and its receptor in Saccharomyces cerevisiae

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

Raths, S.K.

1987-01-01

Alpha-factor is a peptide of thirteen amino acids which is required for mating between the haploid mating types, a and ..cap alpha.., in Saccharomyces cerevisiae. An analogue of alpha-factor, DHP/sup 8/ DHP/sup 11/ Nle/sup 12/ tridecapeptide, was catalytically reduced in the presence of /sup 3/H gas for production of a radiolabeled pheromone suitable for use in binding studies. Incorporation of tritium resulted in /sup 3/H-alpha-factor with high specific activity, purity, biological activity and long shelf-life. Binding studies revealed that alpha-factor interacts with its receptor via a simple, reversible process which obeys the law of mass action. Association and dissociation kineticsmore » indicate values of 2.92 x 10/sup 6/ M/sup /minus/1/ min/sup -1/ for k/sub 1/ and between 4 and 7 x 10/sup /minus/2/ min/sup /minus/1/ for k/sub /minus/1/. Saturation binding studies reveal an equilibrium dissociation constant equal to 2.32 x 10/sup /minus/8/ M which approximate the kinetically-derived K/sub D/ of 2.12 x 10/sup /minus/8/ M. Scatchard and Hill analyses as well as dissociation behavior in the presence of excess unlabeled ligand indicate alpha-factor interacts with a homogeneous population of binding sites which do not interact and exhibit one affinity for the alpha-factor pheromone.« less

Different roles of protein kinase C alpha and delta isoforms in the regulation of neutral sphingomyelinase activity in HL-60 cells.

PubMed Central

Visnjić, D; Batinić, D; Banfić, H

1999-01-01

The signalling mechanisms responsible for the hydrolysis of sphingomyelin mediated by 1,25-dihydroxyvitamin D(3) [1, 25(OH)(2)D(3)] and interferon gamma (IFN-gamma) in HL-60 cells were investigated. IFN-gamma was found to increase selectively the activity of cytosolic, Mg(2+)-independent, neutral sphingomyelinase. The treatment of HL-60 cells with the combination of 1,25(OH)(2)D(3) and IFN-gamma had an additive effect on sphingomyelin hydrolysis, ceramide release and the activity of cytosolic, Mg(2+)-independent, neutral sphingomyelinase. The pretreatment of HL-60 cells with staurosporine, chelerythrine chloride and bisindolylmaleimide abolished the activity of sphingomyelinase in response to 1,25(OH)(2)D(3) and IFN-gamma. Calphostin C, which acts on the regulatory site of protein kinase C (PKC), and Gö 6976, a selective inhibitor of Ca(2+)-dependent PKC isoforms, inhibited the effect of 1,25(OH)(2)D(3) but had no effect on the IFN-gamma-mediated increase in activity of sphingomyelinase. Isoform-specific antibodies were used to deplete different PKC isoforms from cytosol before the treatment of the cytosolic fraction with 1,25(OH)(2)D(3), arachidonic acid (AA) and PMA. The depletion of PKC isoforms beta(1), beta(2), epsilon, eta, mu, zeta and lambda had no effect on the activation of sphingomyelinase induced by 1,25(OH)(2)D(3) or by AA. The depletion of PKC alpha from the cytosol completely abolished the effect of 1,25(OH)(2)D(3) on sphingomyelinase activity but had no effect on the AA-induced activity of sphingomyelinase. PMA had no effect on the activity of sphingomyelinase in either untreated or alpha-depleted cytosol but significantly increased the activity of sphingomyelinase when added to cytosol depleted of PKC delta. Moreover, PMA inhibited the effect of 1,25(OH)(2)D(3) on sphingomyelinase activation but the inhibitory effect was abolished by prior depletion of PKC delta from the cytosol. These studies demonstrate that 1,25(OH)(2)D(3)-induced activation of sphingomyelinase is mediated by PKC alpha. Furthermore, PKC delta had an inhibitory effect on sphingomyelinase, suggesting that the difference between the 1,25(OH)(2)D(3)- and PMA-mediated effects on sphingomyelin turnover depends on the specific regulation of the PKC alpha and PKC delta isoforms. PMID:10585882

Sputum-to-serum hydrogen sulfide ratio as a novel biomarker of predicting future risks of asthma exacerbation.

PubMed

Suzuki, Yasuhito; Saito, Junpei; Kikuchi, Masami; Uematsu, Manabu; Fukuhara, Atsuro; Sato, Suguru; Munakata, Mitsuru

2018-05-14

Increased level of hydrogen sulfide (H 2 S) in sputum is reported to be a new biomarker of neutrophilic airway inflammation in chronic airway disorders. However, the relationship between H 2 S and disease activity remains unclear. We investigated whether H 2 S levels could vary during different conditions in asthma. H 2 S levels in sputum and serum were measured using a sulfide-sensitive electrode in 47 stable asthmatic subjects (S-BA), 21 uncontrolled asthmatic subjects (UC-BA), 26 asthmatic subjects with acute exacerbation (AE-BA), and 15 healthy subjects. Of these, H 2 S levels during stable, as well as exacerbation states were obtained in 13 asthmatic subjects. Sputum H 2 S levels were significantly higher in the AE-BA subjects compared to the UC-BA and healthy subjects (p<0.05). However, serum H 2 S levels in the AE-BA subjects were lower than in the S-BA subjects (p<0.001) and similar to those in healthy subjects. Thus, the sputum-to-serum ratio of H 2 S (H 2 S ratio) in the AE-BA subjects was significantly higher than in the S-BA, UC-BA and healthy subjects (p<0.05). Among all subjects, sputum H 2 S levels showed a trend to decrease with FEV 1% predicted, and significantly positive correlations with sputum neutrophils (%), sputum IL-8, and serum IL-8. A multiple linear regression analysis showed that sputum H 2 S was independently associated with increased sputum neutrophils (%) and decreased FEV 1% predicted (p<0.05) The cut-off level of H 2 S ratio to indicate an exacerbation was ≥0.34 (area under the curve; 0.88, with a sensitivity of 81.8% and specificity of 72.7%, p<0.001). Furthermore, half of the asthmatic subjects with H 2 S ratios higher than the cutoff level experienced asthma exacerbations over the following 3 months after enrollment. The H 2 S ratio may provide useful information on predicting future risks of asthma exacerbation, as well as on obstructive neutrophilic airway inflammation as one of the non-Th2 biomarkers, in asthma. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Flavocoxid counteracts muscle necrosis and improves functional properties in mdx mice: a comparison study with methylprednisolone.

PubMed

Messina, Sonia; Bitto, Alessandra; Aguennouz, M'hammed; Mazzeo, Anna; Migliorato, Alba; Polito, Francesca; Irrera, Natasha; Altavilla, Domenica; Vita, Gian Luca; Russo, Massimo; Naro, Antonino; De Pasquale, Maria Grazia; Rizzuto, Emanuele; Musarò, Antonio; Squadrito, Francesco; Vita, Giuseppe

2009-12-01

Muscle degeneration in dystrophic muscle is exacerbated by the endogenous inflammatory response and increased oxidative stress. A key role is played by nuclear factor(NF)-kappaB. We showed that NF-kappaB inhibition through compounds with also antioxidant properties has beneficial effects in mdx mice, the murine model of Duchenne muscular dystrophy (DMD), but these drugs are not available for clinical studies. We evaluated whether flavocoxid, a mixed flavonoid extract with anti-inflammatory, antioxidant and NF-kappaB inhibiting properties, has beneficial effects in mdx mice in comparison with methylprednisolone, the gold standard treatment for DMD patients. Five-week-old mdx mice were treated for 5 weeks with flavocoxid, methylprednisolone or vehicle. The evaluation of in vivo and ex vivo functional properties and morphological parameters was performed. Serum samples were assayed for oxidative stress markers, creatine-kinase (CK) and leukotriene B-4. Cyclooxygenase-2 (COX-2), 5-lipoxygenase (5-LOX), tumor necrosis factor-alpha, p-38, JNK1 expression was evaluated in muscle by western blot analysis. NF-kappaB binding activity was investigated by electrophoresis mobility shift assay. The administration of flavocoxid: (1) ameliorated functional properties in vivo and ex vivo; (2) reduced CK; (3) reduced the expression of oxidative stress markers and of inflammatory mediators; (4) inhibited NF-kappaB and mitogen-activated protein kinases (MAPKs) signal pathways; (5) reduced muscle necrosis and enhanced regeneration. Our results highlight the detrimental effects of oxidative stress and NF-kappaB, MAPKs and COX/5-LOX pathways in the dystrophic process and show that flavocoxid is more effective in mdx mice than methylprednisolone.

Deleterious effect of oltipraz on extrahepatic cholestasis in bile duct-ligated mice

PubMed Central

Weerachayaphorn, Jittima; Luo, Yuhuan; Mennone, Albert; Soroka, Carol J.; Harry, Kathy; Boyer, James L.

2014-01-01

Background & Aims Oltipraz (4-methyl-5(pyrazinyl-2)-1-2-dithiole-3-thione), a promising cancer preventive agent, has an anti-oxidative activity and ability to enhance glutathione biosynthesis, phase II detoxification enzymes and multidrug resistance-associated protein-mediated efflux transporters. Oltipraz can protect against hepatotoxicity caused by carbon tetrachloride, acetaminophen and alpha-naphthylisothiocyanate. Whether oltipraz has hepato-protective effects on obstructive cholestasis is unknown. Methods We administered oltipraz to mice for 5 days prior to bile duct ligation (BDL) for 3 days. Liver histology, liver function markers, bile flow rates and hepatic expression of profibrogenic genes were evaluated. Results Mice pretreated with oltipraz prior to BDL demonstrated higher levels of serum aminotransferases and more severe liver damage than in control mice. Higher bile flow and glutathione secretion rates were observed in unoperated mice treated with oltipraz than in control mice, suggesting that liver necrosis in oltipraz-treated BDL mice may be related partially to increased bile-acid independent flow and biliary pressure. Oltipraz treatment in BDL mice enhanced -smooth muscle actin expression, consistent with activation of hepatic stellate cells and portal fibroblasts. Matrix metalloproteinases (MMP) 9 and 13 and tissue inhibitors of metalloproteinases (TIMP) 1 and 2 levels were increased in the oltipraz -treated BDL group, suggesting that the secondary phase of liver injury induced by oltipraz might be due to excessive MMP and TIMP secretions which induce remodeling of the extracellular matrix. Conclusions Oltipraz treatment exacerbates the severity of liver injury following BDL and should be avoided as therapy for extrahepatic cholestatic disorders due to bile duct obstruction. PMID:23978715

Altered expression and activation of signal transducers and activators of transcription (STATs) in hepatitis C virus infection: in vivo and in vitro studies.

PubMed

Larrea, E; Aldabe, R; Molano, E; Fernandez-Rodriguez, C M; Ametzazurra, A; Civeira, M P; Prieto, J

2006-08-01

Signal transducers and activators of transcription (STATs) play a critical role in antiviral defence. STAT3 is also important in cell protection against inflammatory damage. STAT proteins are activated by interferons and by hepatoprotective cytokines of the interleukin 6 superfamily, including cardiotrophin 1. We analysed the status of STATs in hepatitis C virus (HCV) infected livers and the relationship between expression and activation of STATs and HCV replication in Huh7 cells transfected with HCV genomic replicon. STAT3alpha expression was reduced in HCV infected livers showing an inverse correlation with serum alanine aminotransferase. In patients with HCV infection, nuclear staining for phosphorylated STAT3 was faint in parenchymal cells (although conspicuous in infiltrating leucocytes), in contrast with strong nuclear staining in hepatocytes from control livers. Expression and activation of STAT1 (a factor activated by both interferon (IFN)-alpha and IFN-gamma) were increased in HCV infected livers, particularly in those with high inflammatory activity. Conversely, phosphorylated STAT2 (a factor selectively activated by IFN-alpha) was undetectable in livers with HCV infection, a finding that was associated with marked downregulation of the two functional subunits of the IFN-alpha receptor. HCV replication in Huh7 cells caused STAT3alpha downregulation and blocked STAT3 phosphorylation by either IFN-alpha or cardiotrophin 1. HCV replication in Huh7 cells also inhibited STAT1 and STAT2 activation by IFN-alpha while there was no impairment of STAT1 phosphorylation by the proinflammatory cytokine IFN-gamma. STAT3 is downregulated in HCV infected livers and in Huh7 cells bearing the full length HCV replicon. HCV replication is associated with impaired Jak-STAT signalling by antiviral and cytoprotective cytokines. These effects may favour viral replication while facilitating the progression of liver disease.

Monocarboxylate and alpha-ketoglutarate carriers from bovine heart mitochondria. Purification by affinity chromatography on immobilized 2-cyano-4-hydroxycinnamate.

PubMed

Bolli, R; Nałecz, K A; Azzi, A

1989-10-25

2-Cyano-4-hydroxycinnamate was covalently linked, through a diazo bond, to Sepharose 4B, which had been elongated with a hydrophobic spacer. A Triton X-100 extract from bovine heart mitochondria was pre-purified by hydroxylapatite chromatography and passed through the 2-cyano-4-hydroxycinnamate affinity resin in the presence of 0.7% deoxycholate. At pH 6 and in the presence of 0.2 M sodium chloride, a single polypeptide with an Mr of 34,000 was eluted. Subsequently, at pH 8 and in the presence of 2-cyano-4-hydroxycinnamate, another single protein with an Mr of 31,500 was released. Both proteins were reconstituted into phospholipid vesicles and their transport activities were measured. High, delta pH-dependent, 2-cyanocinnamate-sensitive pyruvate uptake was measured in vesicles containing only the 34-kDa protein. alpha-Ketobutyrate and other alpha-ketomonocarboxylic acids were competitive inhibitors of the pyruvate uptake, whereas di- and tricarboxylates had only small effects. alpha-Ketoglutarate-alpha-ketoglutarate exchange could only be measured in vesicles containing the 31.5-kDa protein. The molecular weight of this protein and its functional properties were similar to those of the alpha-ketoglutarate carrier isolated by a different method (Bisaccia, Indiveri, C., and Palmieri, F. (1985) Biochim. Biophys. Acta 810, 362-369). 2-Cyano-4-hydroxycinnamate inhibited the alpha-ketoglutarate exchange in a noncompetitive manner with an apparent Ki of 0.7 mM. It is concluded that by the described affinity chromatography procedure, two mitochondrial carriers transporting alpha-ketoacids, i.e. the monocarboxylate and the alpha-ketoglutarate carrier, could be purified in a functionally active state.

The PPAR alpha agonist gemfibrozil is an ineffective treatment for spinal cord injured mice.

PubMed

Almad, Akshata; Lash, A Todd; Wei, Ping; Lovett-Racke, Amy E; McTigue, Dana M

2011-12-01

Peroxisome Proliferator Activated Receptor (PPAR)-α is a key regulator of lipid metabolism and recent studies reveal it also regulates inflammation in several different disease models. Gemfibrozil, an agonist of PPAR-α, is a FDA approved drug for hyperlipidemia and has been shown to inhibit clinical signs in a rodent model of multiple sclerosis. Since many studies have shown improved outcome from spinal cord injury (SCI) by anti-inflammatory and neuroprotective agents, we tested the efficacy of oral gemfibrozil given before or after SCI for promoting tissue preservation and behavioral recovery after spinal contusion injury in mice. Unfortunately, the results were contrary to our hypothesis; in our first attempt, gemfibrozil treatment exacerbated locomotor deficits and increased tissue pathology after SCI. In subsequent experiments, the behavioral effects were not replicated but histological outcomes again were worse. We also tested the efficacy of a different PPAR-α agonist, fenofibrate, which also modulates immune responses and is beneficial in several neurodegenerative disease models. Fenofibrate treatment did not improve recovery, although there was a slight trend for a modest increase in histological tissue sparing. Based on our results, we conclude that PPAR-α agonists yield either no effect or worsen recovery from spinal cord injury, at least at the doses and the time points of drug delivery tested here. Further, patients sustaining spinal cord injury while taking gemfibrozil might be prone to exacerbated tissue damage. Copyright © 2011 Elsevier Inc. All rights reserved.

Antibacterial properties of (2,3)-alpha- and (2,3)-beta-methylene analogs of penicillin G.

PubMed Central

Christenson, J G; Pruess, D L; Talbot, M K; Keith, D D

1988-01-01

The penam nucleus can assume two conformations; these are designated open and closed. The synthetic (2,3)-alpha- and (2,3)-beta-methylenepenams can be regarded as analogs of the open and closed conformations, respectively. It has been shown that the beta-methylenepenams are essentially inactive, suggesting that the closed conformation of penams is also inactive. In this study, we investigated a series of beta-lactams, all of which contained phenylacetamido side chains: penicillin G, the (2,3)-alpha- and (2,3)-beta-methylenepenams, and the 3-acetoxymethyl- and 3-methylcephalosporins. The alpha-methylenepenam and penicillin G were the most active compounds, while the beta-methylene isomer was only poorly active. Results with permeability mutants suggested that the alpha-methylene compound penetrated the outer membrane somewhat more readily than penicillin G did. The intrinsic potency of the alpha-methylenepenam appeared to be similar to that of penicillin G, on the basis of their affinities for penicillin-binding proteins and their abilities to inhibit peptidoglycan synthesis in ether-permeabilized Escherichia coli, while the beta-methylene analog had very poor intrinsic potency. The alpha-methylene analog was about 10-fold more efficient (Vmax/Km) than penicillin G as a substrate for the cephalosporinases from Enterobacter cloacae and Proteus vulgaris, but it was about 40-fold less efficient with penicillinase from Staphylococcus aureus. These results strongly support the hypothesis that the active conformation of penams is the open conformation and suggest that the position in space of the carboxyl group relative to the beta-lactam carbonyl is an important determinant of cephalosporinlike character, as distinct from penicillinlike character. Images PMID:3190190

Identification and characterization of an alternative promoter of the human PGC-1{alpha} gene

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

Yoshioka, Toyo; Inagaki, Kenjiro; Noguchi, Tetsuya, E-mail: noguchi@med.kobe-u.ac.jp

2009-04-17

The transcriptional regulator peroxisome proliferator-activated receptor-{gamma} coactivator-1{alpha} (PGC-1{alpha}) controls mitochondrial biogenesis and energy homeostasis. Although physical exercise induces PGC-1{alpha} expression in muscle, the underlying mechanism of this effect has remained incompletely understood. We recently identified a novel muscle-enriched isoform of PGC-1{alpha} transcript (designated PGC-1{alpha}-b) that is derived from a previously unidentified first exon. We have now cloned and characterized the human PGC-1{alpha}-b promoter. The muscle-specific transcription factors MyoD and MRF4 transactivated this promoter through interaction with a proximal E-box motif. Furthermore, either forced expression of Ca{sup 2+}- and calmodulin-dependent protein kinase IV (CaMKIV), calcineurin A, or the p38 mitogen-activated proteinmore » kinase (p38 MAPK) kinase MKK6 or the intracellular accumulation of cAMP activated the PGC-1{alpha}-b promoter in cultured myoblasts through recruitment of cAMP response element (CRE)-binding protein (CREB) to a putative CRE located downstream of the E-box. Our results thus reveal a potential molecular basis for isoform-specific regulation of PGC-1{alpha} expression in contracting muscle.« less

Antioxidant activities of tocopherols on Fe2+-ascorbate-induced lipid peroxidation in lecithin liposomes.

PubMed

Fukuzawa, K; Tokumura, A; Ouchi, S; Tsukatani, H

1982-07-01

The antioxidant activities of 4 tocopherols, tocol, and a water-soluble model analog of alpha-tocopherol were compared. Egg lecithin liposomes were used and oxidation was catalyzed by Fe2+-ascorbate. The activities decreased in the order alpha greater than beta greater than gamma greater than delta-tocopherol greater than tocol, in agreement with their potencies in vivo. The water-soluble analog was the least effective. Activity depended on the molar ratio of antioxidant to unsaturated lipid, with one molecule each of the alpha-, beta-, gamma-, delta-tocopherol and tocol capable of protecting, respectively, 220, 120, 100, 30 and 20 molecules of polyunsaturated fatty acid. The mechanism of possible antioxidant effect of the compounds used is discussed.

PGC-1{alpha} accelerates cytosolic Ca{sup 2+} clearance without disturbing Ca{sup 2+} homeostasis in cardiac myocytes

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

Chen, Min, E-mail: chenminyx@gmail.com; Yunnan Centers for Diseases Prevention and Control, Kunming 650022; Wang, Yanru

2010-06-11

Energy metabolism and Ca{sup 2+} handling serve critical roles in cardiac physiology and pathophysiology. Peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1{alpha}) is a multi-functional coactivator that is involved in the regulation of cardiac mitochondrial functional capacity and cellular energy metabolism. However, the regulation of PGC-1{alpha} in cardiac Ca{sup 2+} signaling has not been fully elucidated. To address this issue, we combined confocal line-scan imaging with off-line imaging processing to characterize calcium signaling in cultured adult rat ventricular myocytes expressing PGC-1{alpha} via adenoviral transduction. Our data shows that overexpressing PGC-1{alpha} improved myocyte contractility without increasing the amplitude of Ca{sup 2+}more » transients, suggesting that myofilament sensitivity to Ca{sup 2+} increased. Interestingly, the decay kinetics of global Ca{sup 2+} transients and Ca{sup 2+} waves accelerated in PGC-1{alpha}-expressing cells, but the decay rate of caffeine-elicited Ca{sup 2+} transients showed no significant change. This suggests that sarcoplasmic reticulum (SR) Ca{sup 2+}-ATPase (SERCA2a), but not Na{sup +}/Ca{sup 2+} exchange (NCX) contribute to PGC-1{alpha}-induced cytosolic Ca{sup 2+} clearance. Furthermore, PGC-1{alpha} induced the expression of SERCA2a in cultured cardiac myocytes. Importantly, overexpressing PGC-1{alpha} did not disturb cardiac Ca{sup 2+} homeostasis, because SR Ca{sup 2+} load and the propensity for Ca{sup 2+} waves remained unchanged. These data suggest that PGC-1{alpha} can ameliorate cardiac Ca{sup 2+} cycling and improve cardiac work output in response to physiological stress. Unraveling the PGC-1{alpha}-calcium handing pathway sheds new light on the role of PGC-1{alpha} in the therapy of cardiac diseases.« less

CP-25, a Novel Anti-inflammatory and Immunomodulatory Drug, Inhibits the Functions of Activated Human B Cells through Regulating BAFF and TNF-alpha Signaling and Comparative Efficacy with Biological Agents.

PubMed

Zhang, Feng; Shu, Jin-Ling; Li, Ying; Wu, Yu-Jing; Zhang, Xian-Zheng; Han, Le; Tang, Xiao-Yu; Wang, Chen; Wang, Qing-Tong; Chen, Jing-Yu; Chang, Yan; Wu, Hua-Xun; Zhang, Ling-Ling; Wei, Wei

2017-01-01

Paeoniflorin-6'- O -benzene sulfonate (code: CP-25) was the chemistry structural modifications of Paeoniflorin (Pae). CP-25 inhibited B cells proliferation stimulated by B cell activating factor belonging to the TNF family (BAFF) or Tumor necrosis factor alpha (TNF-alpha). CP-25, Rituximab and Etanercept reduced the percentage and numbers of CD19 + B cells, CD19 + CD20 + B cells, CD19 + CD27 + B cells and CD19 + CD20 + CD27 + B cells induced by BAFF or TNF-alpha. There was significant difference between CP-25 and Rituximab or CP-25 and Etanercept. CP-25 down-regulated the high expression of BAFFR, BCMA, and TACI stimulated by BAFF or TNF-alpha. The effects of Rituximab and Etanercept on BAFFR or BCMA were stronger than that of CP-25. CP-25, Rituximab and Etanercept down-regulated significantly the expression of TNFR1 and TNFR2 on B cell stimulated by BAFF or TNF-alpha. CP-25, Rituximab and Etanercept down-regulated the expression of MKK3, P-p38, P-p65, TRAF2, and p52 in B cells stimulated by BAFF and the expression of TRAF2 and P-p65 in B cells stimulated by TNF-alpha. These results suggest that CP-25 regulated moderately activated B cells function by regulating the classical and alternative NF-κB signaling pathway mediated by BAFF and TNF-alpha-TRAF2-NF-κB signaling pathway. This study suggests that CP-25 may be a promising anti-inflammatory immune and soft regulation drug.

Elastase, alpha2-macroglobulin and alkaline phosphatase in crevicular fluid from implants with and without periimplantitis.

PubMed

Plagnat, Dominique; Giannopoulou, Catherine; Carrel, Anne; Bernard, Jean-Pierre; Mombelli, Andrea; Belser, Urs C

2002-06-01

The aim of this investigation was to determine the presence of selected enzymes and enzyme inhibitors in crevicular fluid collected from implants with and without clinical, radiographic and microbiological signs of periimplantitis. Eleven implants with symptoms of periimplantitis in eight patients (four men and four women) were compared to eleven implants in seven subjects (one man and six women) without periimplantitis. Periimplant crevicular fluid (PICF) was collected at the mesial and distal sites of each implant. Alkaline phosphatase activity (ALP) was measured by using p-nitrophenyl-phosphate as substrate, elastase activity (EA) by the use of a low molecular weight fluorogenic substrate, and the inhibitor alpha2-macroglobulin (alpha2M) by ELISA. ALP, EA and alpha2M were detected in the majority of samples in both groups. In comparison to the clinically healthy implants, total amounts of each of these substances were significantly higher in PICF collected around implants with periimplantitis. The mean total amounts of EA, alpha2M and ALP in the healthy group were: EA: 1.8 ng, alpha2M: 3.1 ng, ALP: 24.1 U, and in the periimplantitis group EA: 23.1 ng, alpha2M: 25.2 ng and ALP: 142.3 U. In addition, all three mediators were correlated with the clinical parameters. The results confirm the similarity of the inflammatory response of tissues surrounding implants and natural teeth, and suggest that ALP and EA could be promising markers of bone loss around dental implants.

Dietary vitamin D3 deficiency exacerbates sinonasal inflammation and alters local 25(OH)D3 metabolism.

PubMed

Mulligan, Jennifer K; Pasquini, Whitney N; Carroll, William W; Williamson, Tucker; Reaves, Nicholas; Patel, Kunal J; Mappus, Elliott; Schlosser, Rodney J; Atkinson, Carl

2017-01-01

Patients with chronic rhinosinusitis with nasal polyps (CRSwNP) have been shown to be vitamin D3 (VD3) deficient, which is associated with more severe disease and increased polyp size. To gain mechanistic insights into these observational studies, we examined the impact of VD3 deficiency on inflammation and VD3 metabolism in an Aspergillus fumigatus (Af) mouse model of chronic rhinosinusitis (Af-CRS). Balb/c mice were fed control or VD3 deficient diet for 4 weeks. Mice were then sensitized with intraperitoneal Af, and one week later given Af intranasally every three days for four weeks while being maintained on control or VD3 deficient diet. Airway function, sinonasal immune cell infiltrate and sinonasal VD3 metabolism profiles were then examined. Mice with VD3 deficiency had increased Penh and sRaw values as compared to controls as well as exacerbated changes in sRaw when coupled with Af-CRS. As compared to controls, VD3 deficient and Af-CRS mice had reduced sinonasal 1α-hydroxylase and the active VD3 metabolite, 1,25(OH)2D3. Differential analysis of nasal lavage samples showed that VD3 deficiency alone and in combination with Af-CRS profoundly upregulated eosinophil, neutrophil and lymphocyte numbers. VD3 deficiency exacerbated increases in monocyte-derived dendritic cell (DC) associated with Af-CRS. Conversely, T-regulatory cells were decreased in both Af-CRS mice and VD3 deficient mice, though coupling VD3 deficiency with Af-CRS did not exacerbate CD4 or T-regulatory cells numbers. Lastly, VD3 deficiency had a modifying or exacerbating impact on nasal lavage levels of IFN-γ, IL-6, IL-10 and TNF-α, but had no impact on IL-17A. VD3 deficiency causes changes in sinonasal immunity, which in many ways mirrors the changes observed in Af-CRS mice, while selectively exacerbating inflammation. Furthermore, both VD3 deficiency and Af-CRS were associated with altered sinonasal VD3 metabolism causing reductions in local levels of the active VD3 metabolite, 1,25(OH)2D3, even with adequate circulating levels.

Identification of functional domains within the alpha and beta subunits of beta-hexosaminidase A through the expression of alpha-beta fusion proteins.

PubMed

Tse, R; Wu, Y J; Vavougios, G; Hou, Y; Hinek, A; Mahuran, D J

1996-08-20

There are three human beta-hexosaminidase isozymes which are composed of all possible dimeric combinations of an alpha and/or a beta subunit; A (alpha beta), and B (beta beta), and S (alpha alpha). The amino acid sequences of the two subunits are 60% identical. The homology between the two chains varies with the middle > the carboxy-terminal > > the amino-terminal portions. Although dimerization is required for activity, each subunit contains its own active site and differs in its substrate specificity and thermal stability. The presence of the beta subunit in hexosaminidase A also influences the substrate specificity of the alpha subunit; e.g., in vivo only the A heterodimer can hydrolyze GM2 ganglioside. In this report, we localize functional regions in the two subunits by cellular expression of alpha/beta fusion proteins joined at adjacently aligned residues. First, a chimeric alpha/beta chain was made by replacing the least well-conserved amino-terminal section of the beta chain with the corresponding alpha section. The biochemical characteristics of this protein were nearly identical to hexosaminidase B. Therefore, the most dissimilar regions in the subunits are not responsible for their dissimilar biochemical properties. A second fusion protein was made that also included the more homologous middle section of the alpha chain. This protein expressed the substrate specificity unique to isozymes containing an alpha subunit (A and S). We conclude that the region responsible for the ability of the alpha subunit to bind negatively charged substrates is located within residues alpha 132-283. Interestingly, the remaining carboxy-terminal section from the beta chain, beta 316-556, was sufficient to allow this chimera to hydrolyze GM2 ganglioside with 10% the specific activity of heterodimeric hexosaminidase A. Thus, the carboxy-terminal section of each subunit is likely involved in subunit-subunit interactions.

Determinants of change in physical activity during moderate-to-severe COPD exacerbation

PubMed Central

Esteban, Cristóbal; Quintana, José M; Garcia-Gutierrez, Susana; Anton-Ladislao, Ane; Gonzalez, Nerea; Baré, Marisa; Fernández de Larrea, Nerea; Rivas-Ruiz, Francisco

2016-01-01

Background Data are scarce on patient physical activity (PA) level during exacerbations of chronic obstructive pulmonary disease (eCOPD). The objective of the study was to evaluate the level and determinants of change in PA during an eCOPD. Materials and methods We conducted a prospective cohort study with recruitment from emergency departments (EDs) of 16 participating hospitals from June 2008 to September 2010. Data were recorded on socioeconomic characteristics, dyspnea, forced expiratory volume in 1 second (FEV1%), comorbidities, health-related quality of life, factors related to exacerbation, and PA in a stable clinical condition and during the eCOPD episode. Results We evaluated 2,487 patients. Common factors related to the change in PA during hospital admission or 7 days after discharge to home from the ED were lower PA at baseline and during the first 24 hours after the index evaluation. Age, quality of life, living alone, length of hospital stay, and use of anticholinergic or systemic corticosteroids in treating the exacerbation were associated with the change in PA among hospitalized patients. Predictors of change among patients not admitted to hospital were baseline FEV1% and dyspnea at rest on ED arrival. Conclusion Among the patients evaluated in an ED for an eCOPD, the level and change in PA was markedly variable. Factors associated with exacerbation (PA 24 hours after admission, medication during admission, and length of hospital stay) and variables reflecting patients’ stable clinical condition (low level of PA, age, quality of life, FEV1%) are predictors of the change in PA during a moderate-to-severe eCOPD. PMID:26893555

Alpha Rhythms in Audition: Cognitive and Clinical Perspectives

PubMed Central

Weisz, Nathan; Hartmann, Thomas; Müller, Nadia; Lorenz, Isabel; Obleser, Jonas

2011-01-01

Like the visual and the sensorimotor systems, the auditory system exhibits pronounced alpha-like resting oscillatory activity. Due to the relatively small spatial extent of auditory cortical areas, this rhythmic activity is less obvious and frequently masked by non-auditory alpha-generators when recording non-invasively using magnetoencephalography (MEG) or electroencephalography (EEG). Following stimulation with sounds, marked desynchronizations can be observed between 6 and 12 Hz, which can be localized to the auditory cortex. However knowledge about the functional relevance of the auditory alpha rhythm has remained scarce so far. Results from the visual and sensorimotor system have fuelled the hypothesis of alpha activity reflecting a state of functional inhibition. The current article pursues several intentions: (1) Firstly we review and present own evidence (MEG, EEG, sEEG) for the existence of an auditory alpha-like rhythm independent of visual or motor generators, something that is occasionally met with skepticism. (2) In a second part we will discuss tinnitus and how this audiological symptom may relate to reduced background alpha. The clinical part will give an introduction into a method which aims to modulate neurophysiological activity hypothesized to underlie this distressing disorder. Using neurofeedback, one is able to directly target relevant oscillatory activity. Preliminary data point to a high potential of this approach for treating tinnitus. (3) Finally, in a cognitive neuroscientific part we will show that auditory alpha is modulated by anticipation/expectations with and without auditory stimulation. We will also introduce ideas and initial evidence that alpha oscillations are involved in the most complex capability of the auditory system, namely speech perception. The evidence presented in this article corroborates findings from other modalities, indicating that alpha-like activity functionally has an universal inhibitory role across sensory modalities. PMID:21687444

Rapid activation of ERK1/2 and AKT in human breast cancer cells by cadmium

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

Liu Zhiwei; Yu Xinyuan; Shaikh, Zahir A.

2008-05-01

Cadmium (Cd), an endocrine disruptor, can induce a variety of signaling events including the activation of ERK1/2 and AKT. In this study, the involvement of estrogen receptors (ER) in these events was evaluated in three human breast caner cell lines, MCF-7, MDA-MB-231, and SK-BR-3. The Cd-induced signal activation patterns in the three cell lines mimicked those exhibited in response to 17{beta}-estradiol. Specifically, treatment of MCF-7 cells, that express ER{alpha}, ER{beta} and GPR30, to 0.5-10 {mu}M Cd for only 2.5 min resulted in transient phosphorylation of ERK1/2. Cd also triggered a gradual increase and sustained activation of AKT during the 60more » min treatment period. In SK-BR-3 cells, that express only GPR30, Cd also caused a transient activation of ERK1/2, but not of AKT. In contrast, in MDA-MB-231 cells, that express only ER{beta}, Cd was unable to cause rapid activation of either ERK1/2 or AKT. A transient phosphorylation of ER{alpha} was also observed within 2.5 min of Cd exposure in the MCF-7 cells. While the estrogen receptor antagonist, ICI 182,780, did not prevent the effect of Cd on these signals, specific siRNA against hER{alpha} significantly reduced Cd-induced activation of ERK1/2 and completely blocked the activation of AKT. It is concluded that Cd, like estradiol, can cause rapid activation of ERK1/2 and AKT and that these signaling events are mediated by possible interaction with membrane ER{alpha} and GPR30, but not ER{beta}.« less

Transforming growth factor-{beta} inhibits CCAAT/enhancer-binding protein expression and PPAR{gamma} activity in unloaded bone marrow stromal cells

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

Ahdjoudj, S.; Kaabeche, K.; Holy, X.

2005-02-01

The molecular mechanisms regulating the adipogenic differentiation of bone marrow stromal cells in vivo remain largely unknown. In this study, we investigated the regulatory effects of transforming growth factor beta-2 (TGF-{beta}2) on transcription factors involved in adipogenic differentiation induced by hind limb suspension in rat bone marrow stromal cells in vivo. Time course real-time quantitative reverse-transcription polymerase chain reaction (RT-PCR) analysis of gene expression showed that skeletal unloading progressively increases the expression of CCAAT/enhancer-binding protein (C/EBP){alpha} and C/EBP{beta} {alpha} at 5 days in bone marrow stromal cells resulting in increased peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}2) transcripts at 7 days. TGF-{beta}2more » administration in unloaded rats corrected the rise in C/EBP{alpha} and C/EBP{beta} transcripts induced by unloading in bone marrow stromal cells. This resulted in inhibition of PPAR{gamma}2 expression that was associated with increased Runx2 expression. Additionally, the inhibition of C/EBP{alpha} and C/EBP{beta} expression by TGF-{beta}2 was associated with increased PPAR{gamma} serine phosphorylation in bone marrow stromal cells, a mechanism that inhibits PPAR{gamma} transactivating activity. The sequential inhibitory effect of TGF-{beta}2 on C/EBP{alpha}, C/EBP{beta}, and PPAR{gamma}2 resulted in reduced LPL expression and abolition of bone marrow stromal cell adipogenic differentiation, which contributed to prevent bone loss induced by skeletal unloading. We conclude that TGF-{beta}2 inhibits the excessive adipogenic differentiation of bone marrow stromal cells induced by skeletal unloading by inhibiting C/EBP{alpha}, C/EBP{beta}, and PPAR{gamma} expression and activity, which provides a sequential mechanism by which TGF-{beta}2 regulates adipogenic differentiation of bone marrow stromal cells in vivo.« less

Choline exposure reduces potentiation of N-methyl-D-aspartate toxicity by corticosterone in the developing hippocampus.

PubMed

Mulholland, Patrick J; Self, Rachel L; Harris, Barton R; Littleton, John M; Prendergast, Mark A

2004-11-25

Exposure to high levels of glucocorticoids (GCs) may adversely affect neuronal viability, particularly in the developing hippocampus, via increased function or sensitivity of N-methyl-D-aspartate (NMDA)-type glutamate receptors. Conversely, choline supplementation in the developing brain may reduce the severity of subsequent insult. The present studies aimed to examine the extent to which short-term exposure to high concentrations of corticosterone would produce neuronal injury mediated by NMDA receptor activity. These studies also assessed the ability of choline to prevent this form of injury via interactions with nicotinic acetylcholine receptors (nAChRs) expressing the alpha7 subunit. Organotypic hippocampal slice cultures derived from neonatal rat were pre-treated for 72 h with corticosterone (100 nM) alone or with choline (0.1-10 mM), prior to a brief (1 h) NMDA exposure (5 microM). NMDA exposure produced significant cellular damage, reflected as increased fluorescence of the non-vital marker propidium iodide, in the CA1 region. While exposure to corticosterone alone did not produce damage, pre-treatment of cultures with corticosterone markedly exacerbated NMDA-induced toxicity. Pre-treatment with choline (> or =1 mM) alone or in combination with corticosterone markedly reduced subsequent NMDA toxicity, effects blocked by co-exposure to methyllycaconitine (100 nM), an antagonist active at nAChRs expressing the alpha7 subunit. These data suggest that even short-term exposure to high concentrations of GCs may adversely affect neuronal viability and that choline supplementation protects the brain from NMDA receptor-mediated damage, including that associated with hypercortisolemia.

Cow's milk increases the activities of human nuclear receptors peroxisome proliferator-activated receptors alpha and delta and retinoid X receptor alpha involved in the regulation of energy homeostasis, obesity, and inflammation.

PubMed

Suhara, W; Koide, H; Okuzawa, T; Hayashi, D; Hashimoto, T; Kojo, H

2009-09-01

The nuclear peroxisome proliferator-activated receptors (PPAR) have been shown to play crucial roles in regulating energy homeostasis including lipid and carbohydrate metabolism, inflammatory responses, and cell proliferation, differentiation, and survival. Because PPAR agonists have the potential to prevent or ameliorate diseases such as hyperlipidemia, diabetes, atherosclerosis, and obesity, we have explored new natural agonists for PPAR. For this purpose, cow's milk was tested for agonistic activity toward human PPAR subtypes using a reporter gene assay. Milk increased human PPARalpha activity in a dose-dependent manner with a 3.2-fold increase at 0.5% (vol/vol). It also enhanced human PPARdelta activity in a dose-dependent manner with an 11.5-fold increase at 0.5%. However, it only slightly affected human PPARgamma activity. Ice cream, butter, and yogurt also increased the activities of PPARalpha and PPARdelta, whereas vegetable cream affected activity of PPARdelta but not PPARalpha. Skim milk enhanced the activity of PPAR to a lesser degree than regular milk. Milk and fresh cream increased the activity of human retinoid X receptor (RXR)alpha as well as PPARalpha and PPARdelta, whereas neither affected vitamin D3 receptor, estrogen receptors alpha and beta, or thyroid receptors alpha and beta. Both milk and fresh cream were shown by quantitative real-time PCR to increase the quantity of mRNA for uncoupling protein 2 (UCP2), an energy expenditure gene, in a dose-dependent manner. The increase in UCP2 mRNA was found to be reduced by treatment with PPARdelta-short interfering (si)RNA. This study unambiguously clarified at the cellular level that cow's milk increased the activities of human PPARalpha, PPARdelta, and RXRalpha. The possible role in enhancing the activities of PPARalpha, PPARdelta, and RXRalpha, and the health benefits of cow's milk were discussed.

Treatment of lung disease in alpha-1 antitrypsin deficiency: a systematic review.

PubMed

Edgar, Ross G; Patel, Mitesh; Bayliss, Susan; Crossley, Diana; Sapey, Elizabeth; Turner, Alice M

2017-01-01

Alpha-1 antitrypsin deficiency (AATD) is a rare genetic condition predisposing individuals to chronic obstructive pulmonary disease (COPD). The treatment is generally extrapolated from COPD unrelated to AATD; however, most COPD trials exclude AATD patients; thus, this study sought to systematically review AATD-specific literature to assist evidence-based patient management. Standard review methodology was used with meta-analysis and narrative synthesis (PROSPERO-CRD42015019354). Eligible studies were those of any treatment used in severe AATD. Randomized controlled trials (RCTs) were the primary focus; however, case series and uncontrolled studies were eligible. All studies had ≥10 participants receiving treatment or usual care, with baseline and follow-up data (>3 months). Risk of bias was assessed appropriately according to study methodology. In all, 7,296 studies were retrieved from searches; 52 trials with 5,632 participants met the inclusion criteria, of which 26 studies involved alpha-1 antitrypsin augmentation and 17 concerned surgical treatments (largely transplantation). Studies were grouped into four management themes: COPD medical, COPD surgical, AATD specific, and other treatments. Computed tomography (CT) density, forced expiratory volume in 1 s, diffusing capacity of the lungs for carbon monoxide, health status, and exacerbation rates were frequently used as outcomes. Meta-analyses were only possible for RCTs of intravenous augmentation, which slowed progression of emphysema measured by CT density change, 0.79 g/L/year versus placebo ( P =0.002), and associated with a small increase in exacerbations 0.29/year ( P =0.02). Mortality following lung transplant was comparable between AATD- and non-AATD-related COPD. Surgical reduction of lung volume demonstrated inferior outcomes compared with non-AATD-related emphysema. Intravenous augmentation remains the only disease-specific therapy in AATD and there is evidence that this slows decline in emphysema determined by CT density. There is paucity of data around other treatments in AATD. Treatments for usual COPD may not be as efficacious in AATD, and further studies may be required for this disease group.

Predominant Improvement of Alpha Cell Function after Steroid Therapy in a Patient with Autoimmune Pancreatitis: Case Report.

PubMed

Takeshima, Ken; Ariyasu, Hiroyuki; Iwakura, Hiroshi; Kawai, Shintaro; Uraki, Shinsuke; Inaba, Hidefumi; Furuta, Machi; Warigaya, Kenji; Murata, Shin-Ichi; Akamizu, Takashi

2018-06-01

Autoimmune pancreatitis (AIP) is a subset of inflammatory pancreatic disease, responsive to corticosteroid therapy. It is prone to being affected by diabetes mellitus, but the effectiveness of steroid therapy on pancreatic endocrine function is still controversial. We present a case of AIP, focusing on pancreatic endocrine function after steroid therapy. The patient was referred to our hospital with exacerbation of diabetic control and pancreatic swelling. By admission, the insulin secretory capacity was severely impaired. The patient was diagnosed with AIP and treated with prednisolone, resulting in marked improvement of the pancreatic swelling. Glycemic control worsened transiently after initiation of steroid therapy, but insulin requirements decreased along with tapering prednisolone dosage. Pancreatic cytology showed that the acinar structure had been destroyed, and the islets had disappeared. Insulin and glucagon immunostaining revealed slightly scattered alpha and beta cells within the fibrotic stroma. The patient notably showed improved pancreatic alpha cell function predominantly after steroid therapy, despite partial improvement of beta cell function. An imbalance between alpha and beta cell function may contribute to insufficient diabetic control in some patients with AIP. The pancreatic endocrine function test in combination with pancreatic cytology could be helpful when considering the treatment strategy for diabetic control in patients with AIP.

Inhibition of ribosome recruitment induces stress granule formation independently of eukaryotic initiation factor 2alpha phosphorylation.

PubMed

Mazroui, Rachid; Sukarieh, Rami; Bordeleau, Marie-Eve; Kaufman, Randal J; Northcote, Peter; Tanaka, Junichi; Gallouzi, Imed; Pelletier, Jerry

2006-10-01

Cytoplasmic aggregates known as stress granules (SGs) arise as a consequence of cellular stress and contain stalled translation preinitiation complexes. These foci are thought to serve as sites of mRNA storage or triage during the cell stress response. SG formation has been shown to require induction of eukaryotic initiation factor (eIF)2alpha phosphorylation. Herein, we investigate the potential role of other initiation factors in this process and demonstrate that interfering with eIF4A activity, an RNA helicase required for the ribosome recruitment phase of translation initiation, induces SG formation and that this event is not dependent on eIF2alpha phosphorylation. We also show that inhibition of eIF4A activity does not impair the ability of eIF2alpha to be phosphorylated under stress conditions. Furthermore, we observed SG assembly upon inhibition of cap-dependent translation after poliovirus infection. We propose that SG modeling can occur via both eIF2alpha phosphorylation-dependent and -independent pathways that target translation initiation.

The radioprotective activities of turpentine-induced inflammation and alpha2-macroglobulin: the effect of dexamethasone on the radioprotective efficacy of the inflammation.

PubMed

Sevaljević, Ljiljana; Dobrić, Silva; Bogojević, Desanka; Petrović, Miodrag; Koricanać, Goran; Vulović, Mojca; Kanazir, Dusan; Ribarac-Stepić, Nevena

2003-03-01

This work was aimed at the radioprotective efficacy of turpentine oil (TO), alpha2-Macroglobulin (alpha2-M), Amifostine (Ami) and/or dexamethasone (Dex). These agents were administrated, alone or in combination, prior to irradiation of rats with 6.7 Gy (LD(50/30)). The survival was recorded daily for 4 weeks after irradiation and body weight, peripheral leukocytes and thrombocytes were measured. The plasma concentration of alpha2-M and other acute phase proteins were determined by crossed immunoelectrophoresis. All rats receiving alpha2-M and Ami alone or in combination survived the radiation injury, whereas the rate of survival of TO-treated rats was 90%. Radiation and therapy-induced changes in the expression of acute phase protein genes were atypical for the acute phase reaction. Dex alone was lethal for 45% and 55% of control and irradiated rats, respectively. Pretreatment with 1mg Dex reduced radioprotective efficacy of TO and Ami to 30% and 40%, respectively. Given together TO and Ami provided 70% protection to rats receiving Dex. The TO and alpha2-M enhanced the rate of survival from 50% to 90% and 100%, respectively. In the presence of 1mg Dex the TO-induced radioprotectors and Ami exhibited radiosensitizing rather than radioprotecting activities.

DNA-binding activity of TNF-{alpha} inducing protein from Helicobacter pylori

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

Kuzuhara, T.; Suganuma, M.; Oka, K.

2007-11-03

Tumor necrosis factor-{alpha} (TNF-{alpha}) inducing protein (Tip{alpha}) is a carcinogenic factor secreted from Helicobacter pylori (H. pylori), mediated through both enhanced expression of TNF-{alpha} and chemokine genes and activation of nuclear factor-{kappa}B. Since Tip{alpha} enters gastric cancer cells, the Tip{alpha} binding molecules in the cells should be investigated. The direct DNA-binding activity of Tip{alpha} was observed by pull down assay using single- and double-stranded genomic DNA cellulose. The surface plasmon resonance assay, indicating an association between Tip{alpha} and DNA, revealed that the affinity of Tip{alpha} for (dGdC)10 is 2400 times stronger than that of del-Tip{alpha}, an inactive Tip{alpha}. This suggestsmore » a strong correlation between DNA-binding activity and carcinogenic activity of Tip{alpha}. And the DNA-binding activity of Tip{alpha} was first demonstrated with a molecule secreted from H. pylori.« less

Incidence and impact of painful exacerbations in a cohort with post-treatment persistent endodontic lesions.

PubMed

Yu, Victoria Soo Hoon; Messer, Harold H; Yee, Robert; Shen, Liang

2012-01-01

Painful exacerbations of persistent periapical lesions have unknown incidence and impact on quality of life. This study examined the incidence and impact of painful exacerbations and evaluated potential predictive factors of pain associated with root-filled teeth with persistent lesions after root canal treatment. Patients from a university hospital clinic were screened to identify root-filled teeth with periapical lesions at time of treatment and not resolved at least 4 years later. A clinical and radiographic examination and questionnaire survey were conducted. Patient and treatment characteristics and details of pain experience were studied. Statistical analysis was carried out by using SPSS (version 18). One hundred twenty-seven patients with 185 persistent lesions were recruited. Median age of patients at recruitment was 56 years (range, 21-82 years). Median time since treatment was 5 years (range, 4-38 years). Overall incidence of flare-up (requiring an unscheduled dental visit) was only 5.8% 20 years after treatment. Less severe pain was more frequent, with a combined incidence of 45% pain at 20 years after treatment. Female patients (odds ratio [OR], 2.6; 95% confidence interval [CI], 1.2-6.0; P < .05), treatment involving a mandibular molar or maxillary premolar (OR, 3.7; 95% CI, 1.6-8.6; P < .05), and preoperative pain (OR, 2.9; 95% CI, 1.3-6.7; P < .05) were significantly associated with pain after treatment. The most commonly affected activities during painful exacerbations were eating and tooth brushing, with minimal impact on daily living. The risk of flare-up among persistent lesions was very low. A lower degree of pain was more common, but generally with minimal impact on daily activities. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

High fractional exhaled nitric oxide and sputum eosinophils are associated with an increased risk of future virus-induced exacerbations: A prospective cohort study.

PubMed

Bjerregaard, A; Laing, I A; Backer, V; Sverrild, A; Khoo, S-K; Chidlow, G; Sikazwe, C; Smith, D W; Le Souëf, P; Porsbjerg, C

2017-08-01

The major trigger of asthma exacerbations is infection with a respiratory virus, most commonly rhinovirus. Type 2 inflammation is known to be associated with an increased risk of exacerbations in general. Whether type 2 inflammation at baseline increases the risk of future virus-induced exacerbations is unknown. To assess whether type 2 inflammation is associated with an increased risk of virus-induced exacerbations of asthma. Stable asthmatics had spirometry, skin prick test, measurement of FeNO and sputum induced for differential cell counts. Patients were followed up for 18 months, during which they were assessed at the research unit when they had symptoms of an exacerbation. Nasal swabs collected at these assessments underwent viral detection by PCR. A total of 81 asthma patients were recruited, of which 22 (27%) experienced an exacerbation during the follow-up period. Of these, 15 (68%) had a respiratory virus detected at exacerbation. Sputum eosinophils >1% at baseline increased the risk of having a subsequent virus-induced exacerbation (HR 7.6 95% CI: 1.6-35.2, P=.010) as did having FeNO >25 ppb (HR 3.4 95% CI: 1.1-10.4, P=.033). Established type 2 inflammation during stable disease is a risk factor for virus-induced exacerbations in a real-life setting. Measures of type 2 inflammation, such as sputum eosinophils and FeNO, could be included in the risk assessment of patients with asthma in future studies. © 2017 John Wiley & Sons Ltd.

Tumor necrosis factor-{alpha} induces MMP-9 expression via p42/p44 MAPK, JNK, and nuclear factor-{kappa}B in A549 cells

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

Lin, C.-C.; Tseng, Hsiao-Wei; Hsieh, Hsi-Lung

2008-06-15

Matrix metalloproteinases (MMPs), in particular MMP-9, have been shown to be induced by cytokines including tumor necrosis factor-{alpha} (TNF-{alpha}) and contributes to airway inflammation. However, the mechanisms underlying MMP-9 expression induced by TNF-{alpha} in human A549 cells remain unclear. Here, we showed that TNF-{alpha} induced production of MMP-9 protein and mRNA is determined by zymographic, Western blotting, RT-PCR and ELISA assay, which were attenuated by inhibitors of MEK1/2 (U0126), JNK (SP600125), and NF-{kappa}B (helenalin), and transfection with dominant negative mutants of ERK2 ({delta}ERK) and JNK ({delta}JNK), and siRNAs for MEK1, p42 and JNK2. TNF-{alpha}-stimulated phosphorylation of p42/p44 MAPK and JNKmore » were attenuated by pretreatment with the inhibitors U0126 and SP600125 or transfection with dominant negative mutants of {delta}ERK and {delta}JNK. Furthermore, the involvement of NF-{kappa}B in TNF-{alpha}-induced MMP-9 production was consistent with that TNF-{alpha}-stimulated degradation of I{kappa}B-{alpha} and translocation of NF-{kappa}B into the nucleus which were blocked by helenalin, but not by U0126 and SP600125, revealed by immunofluorescence staining. The regulation of MMP-9 gene transcription by MAPKs and NF-{kappa}B was further confirmed by gene luciferase activity assay. MMP-9 promoter activity was enhanced by TNF-{alpha} in A549 cells transfected with wild-type MMP-9-Luc, which was inhibited by helenalin, U0126, or SP600125. In contrast, TNF-{alpha}-stimulated MMP-9 luciferase activity was totally lost in cells transfected with mutant-NF-{kappa}B MMP-9-luc. Moreover, pretreatment with actinomycin D and cycloheximide attenuated TNF-{alpha}-induced MMP-9 expression. These results suggest that in A549 cells, phosphorylation of p42/p44 MAPK, JNK, and transactivation of NF-{kappa}B are essential for TNF-{alpha}-induced MMP-9 gene expression.« less

Lamina-associated polypeptide 2alpha loss impairs heart function and stress response in mice.

PubMed

Gotic, Ivana; Leschnik, Michael; Kolm, Ursula; Markovic, Mato; Haubner, Bernhard J; Biadasiewicz, Katarzyna; Metzler, Bernhard; Stewart, Colin L; Foisner, Roland

2010-02-05

Lamina-associated polypeptide (LAP)2alpha is a mammalian chromatin-binding protein that interacts with a fraction of A-type lamins in the nuclear interior. Because mutations in lamins and LAP2alpha lead to cardiac disorders in humans, we hypothesized that these factors may play important roles in heart development and adult tissue homeostasis. We asked whether the presence of LAP2alpha was required for normal cardiac function. To study the molecular mechanisms of the disease, we analyzed heart structure and function in complete and conditional Lap2alpha(-/-) mice as well as Lap2alpha(-/-)/Mdx mutants. Unlike conditional deletion of LAP2alpha in late embryonic striated muscle, its complete knockout caused systolic dysfunction in young mice, accompanied by sporadic fibrosis in old animals, as well as deregulation of major cardiac transcription factors GATA4 and myocyte enhancer factor 2c. Activation of compensatory pathways, including downregulation of beta-adrenergic receptor signaling, resulted in reduced responsiveness of the myocardium to chronic beta-adrenergic stimulation and stalled the progression of LAP2alpha-deficient hearts from hypertrophy toward cardiac failure. Dystrophin deficiency in an Mdx background resulted in a transient rescue of the Lap2alpha(-/-) phenotype. Our data suggest a novel role of LAP2alpha in the maintenance of cardiac function under normal and stress conditions.

Selective blockade by nicergoline of vascular responses elicited by stimulation of alpha 1A-adrenoceptor subtype in the rat.

PubMed

Alvarez-Guerra, M; Bertholom, N; Garay, R P

1999-01-01

The alpha 1-adrenergic blocking activity of nicergoline was re-examined in rats, with a particular emphasis on alpha 1-adrenoceptor subtypes. In pithed rats, nicergoline and prazosin infused at a single small dose (0.5 microgram/kg/min i.v.) produced a substantial and identical shift to the right of the control dose pressor response curve to the specific alpha 1-agonist cirazoline (ED50 = 4.0 +/- 0.1, 4.0 +/- 0.1 and 0.9 +/- 0.01 microgram/kg i.v. for nicergoline, prazosin and vehicle respectively). In the isolated perfused mesenteric vascular bed, nicergoline strongly inhibited the pressor responses elicited by cirazoline, with approximately 40-fold higher potency (pA2 = 11.1 +/- 0.3) than prazosin (pA2 = 9.5 +/- 0.3). Conversely, nicergoline was 20-fold less potent than prazosin to antagonize the contractile effects of cirazoline in isolated endothelium-denuded aorta (pA2 = 8.6 +/- 0.2 and 9.9 +/- 0.2 for nicergoline and prazosin respectively). Pretreatment of mesenteric vascular beds with chloroethylclonidine did not significantly modify nicergoline antagonistic potency (pA2 = 10.6 +/- 0.2). Nicergoline displaced [3H]-prazosin bound to rat forebrain membranes pretreated with chloroethylclonidine (pKi = 9.9 +/- 0.2) at concentrations 60-fold lower than in rat liver membranes (pKi = 8.1 +/- 0.2). Finally, of the nicergoline metabolites studied, lumilysergol acted as a modest alpha 1 antagonist (bromonicotinic acid was devoid of alpha 1 antagonist activity). In conclusion, nicergoline is a potent and selective alpha 1A-adrenoceptor subtype antagonist, an alpha 1-adrenoceptor subtype which is mainly represented in resistance arteries.

Sympathetic activation of cat spinal neurons responsive to noxious stimulation of deep tissues in the low back.

PubMed

Gillette, R G; Kramis, R C; Roberts, W J

1994-01-01

Prior findings from diverse studies have indicated that activity in axons located in the lumbar sympathetic chains contributes to the activation of spinal pain pathways and to low back pain; these studies have utilized sympathetic blocks in patients, electrical stimulation of the chain in conscious humans, and neuroanatomical mapping of afferent fiber projections. In the present study, dorsal horn neurons receiving nociceptor input from lumbar paraspinal tissues were tested for activation by electrical stimulation of the lumbar sympathetic chain in anesthetized cats. Of 83 neurons tested, 70% were responsive to sympathetic trunk stimulation. Excitatory responses, observed in both nociceptive specific and wide-dynamic-range neurons, were differentiable into two classes: non-entrained and entrained responses. Non-entrained responses were attenuated or blocked by systemic administration of the alpha-adrenergic antagonist phentolamine and are thought to result from sympathetic efferent activation of primary afferents in the units' receptive fields. Entrained responses were unaffected by phentolamine and are thought to result from electrical activation of somatic and/or visceral afferent fibers ascending through the sympathetic trunk into the dorsal horn. These findings from nocireceptive neurons serving lumbar paraspinal tissues suggest that low back pain may be exacerbated by activity in both efferent and afferent fibers located in the lumbar sympathetic chain, the efferent actions being mediated indirectly through sympathetic-sensory interactions in somatic and/or visceral tissues.

On the Efficiency of Individualized Theta/Beta Ratio Neurofeedback Combined with Forehead EMG Training in ADHD Children.

PubMed

Bazanova, Olga M; Auer, Tibor; Sapina, Elena A

2018-01-01

Background: Neurofeedback training (NFT) to decrease the theta/beta ratio (TBR) has been used for treating hyperactivity and impulsivity in attention deficit hyperactivity disorder (ADHD); however, often with low efficiency. Individual variance in EEG profile can confound NFT, because it may lead to influencing non-relevant activity, if ignored. More importantly, it may lead to influencing ADHD-related activities adversely, which may even result in worsening ADHD symptoms. Electromyogenic (EMG) signal resulted from forehead muscles can also explain the low efficiency of the NFT in ADHD from both practical and psychological point-of-view. The first aim of this study was to determine EEG and EMG biomarkers most related to the main ADHD characteristics, such as impulsivity and hyperactivity. The second aim was to confirm our hypothesis that the efficiency of the TBR NFT can be increased by individual adjustment of the frequency bands and simultaneous training on forehead muscle tension. Methods: We recruited 94 children diagnosed with ADHD (ADHD) and 23 healthy controls (HC). All participants were male and aged between six and nine. Impulsivity and attention were assessed with Go/no-Go task and delayed gratification task, respectively; and 19-channel EEG and forehead EMG were recorded. Then, the ADHD group was randomly subdivided into (1) standard, (2) individualized, (3) individualized+EMG, and (4) sham NFT (control) groups. The groups were compared based on TBR and EEG alpha activity, as well as hyperactivity and impulsivity three times: pre-NFT, post-NFT and 6 months after the NFT (follow-up). Results: ADHD children were characterized with decreased individual alpha peak frequency, alpha bandwidth and alpha amplitude suppression magnitude, as well as with increased alpha1/alpha2 (a1/a2) ratio and scalp muscle tension when c (η 2 ≥ 0.212). All contingent TBR NFT groups exhibited significant NFT-related decrease in TBR not evident in the control group. Moreover, we detected a higher overall alpha activity in the individualized but not in the standard NFT group. Mixed MANOVA considering between-subject factor GROUP and within-subject factor TIME showed that the individualized+EMG group exhibited the highest level of clinical improvement, which was associated with increase in the individual alpha activity at the 6 months follow-up when comparing with the other approaches (post hoc t = 3.456, p = 0.011). Conclusions: This study identified various (adjusted) alpha activity metrics as biomarkers with close relationship with ADHD symptoms, and demonstrated that TBR NFT individually adjusted for variances in alpha activity is more successful and clinically more efficient than standard, non-individualized NFT. Moreover, these training effects of the individualized TBR NFT lasted longer when combined with EMG.

Crystallographic structure of human beta-hexosaminidase A: interpretation of Tay-Sachs mutations and loss of GM2 ganglioside hydrolysis.

PubMed

Lemieux, M Joanne; Mark, Brian L; Cherney, Maia M; Withers, Stephen G; Mahuran, Don J; James, Michael N G

2006-06-16

Lysosomal beta-hexosaminidase A (Hex A) is essential for the degradation of GM2 gangliosides in the central and peripheral nervous system. Accumulation of GM2 leads to severely debilitating neurodegeneration associated with Tay-Sachs disease (TSD), Sandoff disease (SD) and AB variant. Here, we present the X-ray crystallographic structure of Hex A to 2.8 A resolution and the structure of Hex A in complex with NAG-thiazoline, (NGT) to 3.25 A resolution. NGT, a mechanism-based inhibitor, has been shown to act as a chemical chaperone that, to some extent, prevents misfolding of a Hex A mutant associated with adult onset Tay Sachs disease and, as a result, increases the residual activity of Hex A to a level above the critical threshold for disease. The crystal structure of Hex A reveals an alphabeta heterodimer, with each subunit having a functional active site. Only the alpha-subunit active site can hydrolyze GM2 gangliosides due to a flexible loop structure that is removed post-translationally from beta, and to the presence of alphaAsn423 and alphaArg424. The loop structure is involved in binding the GM2 activator protein, while alphaArg424 is critical for binding the carboxylate group of the N-acetyl-neuraminic acid residue of GM2. The beta-subunit lacks these key residues and has betaAsp452 and betaLeu453 in their place; the beta-subunit therefore cleaves only neutral substrates efficiently. Mutations in the alpha-subunit, associated with TSD, and those in the beta-subunit, associated with SD are discussed. The effect of NGT binding in the active site of a mutant Hex A and its effect on protein function is discussed.

RESPIRE 2: a phase III placebo-controlled randomised trial of ciprofloxacin dry powder for inhalation in non-cystic fibrosis bronchiectasis.

PubMed

Aksamit, Timothy; De Soyza, Anthony; Bandel, Tiemo-Joerg; Criollo, Margarita; Elborn, J Stuart; Operschall, Elisabeth; Polverino, Eva; Roth, Katrin; Winthrop, Kevin L; Wilson, Robert

2018-01-01

We evaluated the efficacy and safety of ciprofloxacin dry powder for inhalation (DPI) in patients with non-cystic fibrosis bronchiectasis, two or more exacerbations in the previous year and predefined sputum bacteria.Patients were randomised 2:1 to twice-daily ciprofloxacin DPI 32.5 mg or placebo in 14- or 28-day on/off treatment cycles for 48 weeks. Primary end-points were time to first exacerbation and frequency of exacerbations. Enrolling countries and α level split (0.049 and 0.001 for 14- and 28-day cycles, respectively) differed from RESPIRE 1.Patients were randomised to ciprofloxacin DPI (14 days on/off (n=176) or 28 days on/off (n=171)) or placebo (14 days on/off (n=88) or 28 days on/off (n=86)). The exacerbation rate was low across treatment arms (mean±sd 0.6±0.9). Active treatment showed trends to prolonged time to first exacerbation (ciprofloxacin DPI 14 days on/off: hazard ratio 0.87, 95.1% CI 0.62-1.21; p=0.3965; ciprofloxacin DPI 28 days on/off: hazard ratio 0.71, 99.9% CI 0.39-1.27; p=0.0511) and reduced frequency of exacerbations (ciprofloxacin DPI 14 days on/off: incidence rate ratio 0.83, 95.1% CI 0.59-1.17; p=0.2862; ciprofloxacin DPI 28 days on/off: incidence rate ratio 0.55, 99.9% CI 0.30-1.02; p=0.0014), although neither achieved statistical significance. Ciprofloxacin DPI was well tolerated.Trends towards clinical benefit were seen with ciprofloxacin DPI, but primary end-points were not met. Copyright ©ERS 2018.

Pavietin, a coumarin from Aesculus pavia with antifungal activity.

PubMed

Curir, Paolo; Galeotti, Francesco; Dolci, Marcello; Barile, Elisa; Lanzotti, Virginia

2007-10-01

A new prenylated coumarin, S-6-[2-(hydroxymethyl)butoxy]-7-hydroxy-4-methyl-2 H-chromen-2-one ( 1), named pavietin, has been isolated from the leaves of an Aesculus pavia genotype along with three known flavonol glycosides, quercetin 3- O-alpha-rhamnoside (quercitrin, 2), quercetin 3- O-alpha-arabinoside ( 3), and isorhamnetin 3- O-alpha-arabinoside (distichin, 4). The chemical structure of compound 1 was determined by chemical and spectroscopic methods, inclusive of UV, MS, and 1D and 2D NMR experiments. It showed appreciable antimicrobial properties against several pathogens, displaying a significant antifungal activity toward one of the main fungal parasites of Aesculus species, Guignardia aesculi. The same biological tests performed with a mixture of flavonoids 2- 4 resulted in weak or no activity. Compound 1 was undetectable in Aesculus hippocastanum, a closely related species lacking resistance to fungal pathogens. The possible role of 1 in plant resistance is discussed.

[Motivation effect on power changes in the brain biopotentials in the figurative and verbal creativity tasks].

PubMed

Razumnikova, O M; Vol'f, N V; Tarasova, I V

2007-01-01

Effect of extrinsic motivation stimulating the most original problem solving during verbal and figurative divergent thinking was studied by EEG mapping. The righthanded university students (27 males and 26 females) participated in the experiments. An instruction "to create the most original solution" as compared to condition with an instruction "to create any solution" induced an increase in the baseline power of the alpha 1 and alpha 2 rhythms most pronounced in the posterior cortex. Task-related desynchronization of the alpha rhythms was higher but the beta-2 synchronization was lower after the former than after the latter instruction. Differences in the asymmetry of the alpha 1 and alpha 2 rhythms in the parietal and temporal regions of hemispheres suggested the right hemisphere dominance in intrinsic alertness and evoked activation related to divergent thinking. The findings were common and gender-independent in both figurative and verbal tasks suggesting a generalized influence of extrinsic motivation on creative activity.

Anti-inflammatory effects of polyunsaturated fatty acids in THP-1 cells

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

Zhao Guixiang; Etherton, Terry D.; Department of Dairy and Animal Science, Pennsylvania State University, University Park, PA

2005-10-28

The effects of linoleic acid (LA), {alpha}-linolenic acid (ALA), and docosahexaenoic acid (DHA) were compared to that of palmitic acid (PA), on inflammatory responses in human monocytic THP-1 cells. When cells were pre-incubated with fatty acids for 2-h and then stimulated with lipopolysaccharide for 24-h in the presence of fatty acids, secretion of interleukin (IL)-6, IL-1{beta}, and tumor necrosis factor-{alpha} (TNF{alpha}) was significantly decreased after treatment with LA, ALA, and DHA versus PA (P < 0.01 for all); ALA and DHA elicited more favorable effects. These effects were comparable to those for 15-deoxy-{delta}{sup 12,14}-prostaglandin J2 (15d-PGJ2) and were dose-dependent. Inmore » addition, LA, ALA, and DHA decreased IL-6, IL-1{beta}, and TNF{alpha} gene expression (P < 0.05 for all) and nuclear factor (NF)-{kappa}B DNA-binding activity, whereas peroxisome proliferator-activated receptor-{gamma} (PPAR{gamma}) DNA-binding activity was increased. The results indicate that the anti-inflammatory effects of polyunsaturated fatty acids may be, in part, due to the inhibition of NF-{kappa}B activation via activation of PPAR{gamma}.« less

Alpha-mannosidase activity in goats fed with Sida carpinifolia.

PubMed

Bedin, Marisete; Moleta Colodel, Edson; Viapiana, Marli; Matte, Ursula; Driemeier, David; Giugliani, Roberto

2010-03-01

Human alpha-mannosidosis results from alpha-mannosidase deficiency and progressive accumulation of mannose-rich oligosaccharides in lysosomes. Two days before Saanen goats were fed with Sida carpinifolia, alpha-mannosidase activity in leukocytes was 128+/-28 nmoles4-MU/h/mgprotein (first trial) and 104+/-6 nmoles4-MU/h/mgprotein (second trial). At day 5, after the introduction of S. carpinifolia diet, the alpha-mannosidase activity in leukocytes was significantly increased, both in the first (288+/-13 nmoles4-MU/h/mgprotein) and in the second trial (303+/-45 nmoles4-MU/h/mgprotein), and it returned to normal levels 2 days after the withdrawal of the plant from the diet (114+/-7 nmoles4-MU/h/mgprotein in first trial, and 108+/-25 nmoles4-MU/h/mgprotein in the second one). Plasma alpha-mannosidase activity decreased significantly 4 days after animal exposure to the S. carpinifolia diet (769+/-167 nmoles4-MU/h/ml) and returned to normal values 10 days after the withdrawal of the plant from the diet (1289+/-163 nmoles4-MU/h/ml). Thin-layer chromatography showed an abnormal excretion of oligosaccharides in urine as of day 2 after diet exposure, which persisted until one day after the withdrawal of the plant. Animals presented neurological clinical signs beginning at day 37 (in the first trial) and at day 25 (in the second trial) after being fed with the plant. The results obtained herein suggest that oligosaccharides observed in urine are a result of a decrease in alpha-mannosidase activity in plasma. S. carpinifolia seems to have other compounds that act on alpha-mannosidase enzyme in leukocytes in a competitive manner with swainsonine. The increase in alpha-mannosidase enzyme in leukocytes could be attributed to one of these compounds present in S. carpinifolia. Copyright 2009 Elsevier GmbH. All rights reserved.

Lung function, symptoms and inflammation during exacerbations of non-cystic fibrosis bronchiectasis: a prospective observational cohort study.

PubMed

Brill, Simon E; Patel, Anant R C; Singh, Richa; Mackay, Alexander J; Brown, Jeremy S; Hurst, John R

2015-02-07

Exacerbations of non-cystic fibrosis bronchiectasis cause significant morbidity but there are few detailed data on their clinical course and associated physiological changes. The biology of an exacerbation has not been previously described. This was a prospective observational cohort study of 32 outpatients with non-cystic fibrosis bronchiectasis conducted between August 2010 and August 2012. Patients completed a symptom diary card and measured their peak expiratory flow rate (PEFR) daily. Exacerbations were defined as oral antibiotic treatment taken for a worsening of respiratory symptoms. Symptoms and peak flow at exacerbation were analysed, and further measurements including the COPD Assessment Test (CAT) and inflammatory markers were also compared to baseline values. At baseline, health status was significantly related to lung function, prognostic severity and systemic inflammation. 51 exacerbations occurred in 22 patients. Exacerbation symptoms began a median (interquartile range) of 4 (2, 7) days before treatment started and the median exacerbation duration was 16 (10, 29) days. 16% had not recovered by 35 days. At exacerbation, mean PEFR dropped by 10.6% (95% confidence interval 6.9-14.2, p < 0.001) and mean CAT score increased by 6.3 units (3.6-9.1, p = 0.001), median symptom count by 4 (2.25, 6, p < 0.001), and mean CRP by 9.0mg/L (2.3-15.8, p = 0.011). Exacerbations where PEFR fell by ≥10% were longer with more symptoms at onset. Exacerbations of non-CF bronchiectasis are inflammatory events, with worsened symptoms, lung function and health status, and a prolonged recovery period. Symptom diary cards, PEFR and CAT scores are responsive to changes at exacerbation and may be useful tools for their detection and monitoring.

Respiratory effect of beta-blockers in people with asthma and cardiovascular disease: population-based nested case control study.

PubMed

Morales, Daniel R; Lipworth, Brian J; Donnan, Peter T; Jackson, Cathy; Guthrie, Bruce

2017-01-27

Cardiovascular disease (CVD) is a common comorbidity in people with asthma. However, safety concerns have caused heterogeneity in clinical guideline recommendations over the use of cardioselective beta-blockers in people with asthma and CVD, partly because risk in the general population has been poorly quantified. The aim of this study was to measure the risk of asthma exacerbations with beta-blockers prescribed to a general population with asthma and CVD. Linked data from the UK Clinical Practice Research Datalink was used to perform nested case-control studies among people with asthma and CVD matched on age, sex and calendar time. Adjusted incidence rate ratios (IRR) were calculated for the association between oral beta-blocker use and moderate asthma exacerbations (rescue oral steroids) or severe asthma exacerbations (hospitalisation or death) using conditional logistic regression. The cohort consisted of 35,502 people identified with active asthma and CVD, of which 14.1% and 1.2% were prescribed cardioselective and non-selective beta-blockers, respectively, during follow-up. Cardioselective beta-blocker use was not associated with a significantly increased risk of moderate or severe asthma exacerbations. Consistent results were obtained following sensitivity analyses and a self-controlled case series approach. In contrast, non-selective beta-blockers were associated with a significantly increased risk of moderate asthma exacerbations when initiated at low to moderate doses (IRR 5.16, 95% CI 1.83-14.54, P = 0.002), and both moderate and severe exacerbations when prescribed chronically at high dose (IRR 2.68, 95% CI 1.08-6.64, P = 0.033 and IRR 12.11, 95% CI 1.02-144.11, P = 0.048, respectively). Cardioselective beta-blockers prescribed to people with asthma and CVD were not associated with a significantly increased risk of moderate or severe asthma exacerbations and potentially could be used more widely when strongly indicated.

Reversal of behavioral depression by infusion of an alpha-2 adrenergic agonist into the locus coeruleus.

PubMed

Simson, P G; Weiss, J M; Hoffman, L J; Ambrose, M J

1986-04-01

This experiment demonstrated that behavioral depression produced by exposure of rats to strong uncontrollable shocks could be reversed by infusion of the alpha-2 adrenergic agonist clonidine into the region of the locus coeruleus (LC). A 20-min infusion, through bilateral cannulae, into the locus coeruleus of clonidine, piperoxane (alpha-2 antagonist) or inactive vehicle (0.85% saline), was given beginning 70 min after the animals were removed from the stress situation. The dose and volume of drug given in the infusion (0.16 microgram/microliter, 0.1 microliter/min) had been previously shown to produce effects specific to the locus coeruleus (Weiss, Simson, Hoffman, Ambrose, Cooper and Webster, 1986; Neuropharmacology 25: 367-384). At the conclusion of the infusion, active behavior of animals was measured in a 15-min swim test. Results showed that stressed animals infused with vehicle exhibited significantly less active behavior in the swim test than did non-stressed animals infused with vehicle, thereby showing the usual behavioral depression seen after exposure to an uncontrollable stress. Stressed animals infused with clonidine showed no difference in active behavior in comparison to non-stressed animals infused with vehicle and showed significantly more activity than did the stressed animals infused with vehicle. Stressed animals infused with piperoxane showed no significant difference in activity in comparison to the stressed animals infused with vehicle and were significantly less active than either the non-stressed animals infused with vehicle or the stressed animals infused with clonidine. Thus, infusion into the locus coeruleus of the alpha-2 agonist clonidine, but not the alpha-2 antagonist piperoxane, eliminated behavioral depression.(ABSTRACT TRUNCATED AT 250 WORDS)

PPAR-α, a lipid-sensing transcription factor, regulates blood–brain barrier efflux transporter expression

PubMed Central

More, Vijay R; Campos, Christopher R; Evans, Rebecca A; Oliver, Keith D; Chan, Gary NY; Miller, David S

2016-01-01

Lipid sensor peroxisome proliferator-activated receptor alpha (PPAR-α) is the master regulator of lipid metabolism. Dietary release of endogenous free fatty acids, fibrates, and certain persistent environmental pollutants, e.g. perfluoroalkyl fire-fighting foam components, are peroxisome proliferator-activated receptor alpha ligands. Here, we define a role for peroxisome proliferator-activated receptor alpha in regulating the expression of three ATP-driven drug efflux transporters at the rat and mouse blood–brain barriers: P-glycoprotein (Abcb1), breast cancer resistance protein (Bcrp/Abcg2), and multidrug resistance-associated protein 2 (Mrp2/Abcc2). Exposing isolated rat brain capillaries to linoleic acid, clofibrate, or PKAs increased the transport activity and protein expression of the three ABC transporters. These effects were blocked by the PPAR-α antagonist, GW6471. Dosing rats with 20 mg/kg or 200 mg/kg of clofibrate decreased the brain accumulation of the P-glycoprotein substrate, verapamil, by 50% (in situ brain perfusion; effects blocked by GW6471) and increased P-glycoprotein expression and activity in capillaries ex vivo. Fasting C57Bl/6 wild-type mice for 24 h increased both serum lipids and brain capillary P-glycoprotein transport activity. Fasting did not alter P-glycoprotein activity in PPAR-α knockout mice. These results indicate that hyperlipidemia, lipid-lowering fibrates and exposure to certain fire-fighting foam components activate blood–brain barrier peroxisome proliferator-activated receptor alpha, increase drug efflux transporter expression and reduce drug delivery to the brain. PMID:27193034

Antinociceptive synergism of MD-354 and clonidine. Part II. The alpha-adrenoceptor component.

PubMed

Young, Shawquia; Vainio, Minna; Scheinin, Mika; Dukat, Małgorzata

2010-08-01

Previously, we reported that antinociceptive synergism of a 5-HT(3)/alpha(2)-adrenoceptor ligand MD-354 (m-chlorophenylguanidine) and clonidine combination occurs, in part, through a 5-HT(3) receptor antagonist mechanism. In the present investigation, a possible role for alpha(2)-adrenoceptors was examined. Mechanistic studies using yohimbine (a subtype non-selective alpha(2)-adrenoceptor antagonist), BRL 44408 (a preferential alpha(2A)-adrenoceptor antagonist) and imiloxan (a preferential alpha(2B/C)-adrenoceptor antagonist) on the antinociceptive actions of a MD-354/clonidine combination were conducted. Subcutaneous pre-treatment with all three antagonists inhibited the antinociceptive synergism of MD-354 and clonidine in the mouse tail-flick assay in a dose-dependent manner (AD(50) = 0.33, 2.1, and 0.17 mg/kg, respectively). Enhancement of clonidine antinociception by MD-354 did not potentiate clonidine's locomotor suppressant activity in a mouse locomotor assay. When [ethyl-3H]RS-79948-197 was used as radioligand, MD-354 displayed almost equal affinity to alpha(2A)- and alpha(2B)-adrenoceptors (K(i) = 110 and 220 nM) and showed lower affinity at alpha(2C)-adrenoceptors (K(i) = 4,700 nM). MD-354 had no subtype-selectivity for the alpha(2)-adrenoceptor subtypes as an antagonist in functional [35S]GTPgammaS binding assays. MD-354 was a weak partial agonist at alpha(2A)-adrenoceptors. Overall, in addition to the 5-HT(3) receptor component, the present investigation found MD-354 to be a weak partial alpha(2A)-adrenoceptor agonist that enhances clonidine's thermal antinociceptive actions through an alpha(2)-adrenoceptor-mediated mechanism without augmenting sedation.

The characteristics of the (alpha V371C)3(beta R337C)3 gamma double mutant subcomplex of the TF1-ATPase indicate that the catalytic site at the alpha TP-beta TP interface with bound MgADP in crystal structures of MF1 represents a catalytic site containing inhibitory MgADP.

PubMed

Bandyopadhyay, Sanjay; Muneyuki, Eiro; Allison, William S

2005-02-22

In the MF(1) crystal structure with the MgADP-fluoroaluminate complex bound to two catalytic sites [Menz, R. I., Walker, J. E., and Leslie, A. G. W. (2001) Cell 106, 331-341], the guanidinium of betaR(337) is within 2.9 A of the alpha-oxygen of alphaS(370) and 3.7 A of a methyl group of alphaV(371) at the alpha(E)-beta(HC) interface. To examine the functional role of this contact, the (alphaV(371)C)(3)(betaR(337)C)(3)gamma subcomplex of the TF(1)-ATPase was prepared and characterized. Steady state ATPase activity of the reduced double-mutant is 30% of that of the wild type. Inactivation of the double mutant containing empty catalytic sites or MgADP bound to one catalytic site with CuCl(2) cross-linked two alpha-beta pairs, whereas a single alpha-beta pair cross-linked when at least two catalytic sites contained MgADP. The reduced double mutant hydrolyzed substoichiometric ATP 100-fold more rapidly than the enzyme containing two cross-linked alpha-beta pairs. Addition of AlCl(3) and NaF to the reduced double mutant after incubation with stoichiometric MgADP or 200 microM MgADP irreversibly inactivated the steady state ATPase activity with rate constants of 1.5 x10(-2) and 4.1 x 10(-2) min(-1), respectively. In contrast, addition of AlCl(3) and NaF to the cross-linked enzyme after incubation with stoichiometric or 200 microM MgADP irreversibly inactivated ATPase activity with a common rate constant of approximately 10(-4) min(-1). Correlation of these results with crystal structures of MF(1) suggests that the catalytic site at the alpha(TP)-beta(TP) interface is loaded first upon addition of nucleotides to nucleotide-depleted F(1)-ATPases and that the catalytic site at the alpha(TP)-beta(TP) interface with bound MgADP in crystal structures represents a catalytic site containing inhibitory MgADP.

Organocatalysed asymmetric beta-amination and multicomponent syn-selective diamination of alpha,beta-unsaturated aldehydes.

PubMed

Jiang, Hao; Nielsen, Johanne B; Nielsen, Martin; Jørgensen, Karl Anker

2007-01-01

An easy and affordable route for obtaining chiral beta-aminated- and alpha,beta-diaminated aldehydes, 1,3-aminoalcohols, and related compounds by using organocatalysis is presented. The chiral secondary amine (S)-2-[bis(3,5-bistrifluoromethylphenyl)trimethylsilanyloxymethyl]pyrrolidine is used as the catalyst to activate alpha,beta-unsaturated aldehydes, which allows succinimide to add in a 1,4-regio- and stereoselective fashion thereby forming N-protected 1,3-aminoaldehydes in good yields and enantioselectivities. This is followed by two easy transformations giving rise to optically active 1,3-aminoalcohols, a common motif in many biologically active compounds, for example, fibrinogen receptor antagonists. Furthermore, optically active alpha,beta-syn-diaminated aldehydes were obtained by the addition of diethyl azodicarboxylate in a one-pot reaction.

Induced expression of mRNA for IL-5, IL-6, TNF-alpha, MIP-2 and IFN-gamma in immunologically activated rat peritoneal mast cells: inhibition by dexamethasone and cyclosporin A.

PubMed

Williams, C M; Coleman, J W

1995-10-01

We examined the capacity of purified rat peritoneal connective tissue-type mast cells (PMC) to express mRNA for several cytokines. Stimulation of PMC with anti-IgE for 4 hr induced the expression of mRNA encoding interleukin-5 (IL-5), IL-6, tumour necrosis factor-alpha (TNF-alpha), macrophage inflammatory protein-2 (MIP-2) and interferon-gamma (IFN-gamma). Unstimulated PMC expressed detectable mRNA for TNF-alpha but not for the other four cytokines. Incubation of PMC with cyclosporin A (CsA) or dexamethasone (DEX), each at 10(-6) M for 24 hr, significantly inhibited the induced expression of mRNA for each of the five cytokines, and also inhibited release of biologically active TNF-alpha. Throughout these experiments mRNA levels of the housekeeping gene G3PDH were not altered by stimulation with anti-IgE or incubation with CsA or DEX. We conclude that immunological activation of rat PMC induces gene expression of several cytokines and that expression of these genes can be inhibited by immunosuppressive drugs.

Neurospora crassa alpha-ketoglutarate dehydrogenase complex: description, resolution of components and catalytic properties.

PubMed

Bessam, H; Mareck, A M; Foucher, B

1989-01-27

A method is proposed for the purification of the Neurospora crassa alpha-ketoglutarate dehydrogenase complex, and the main points for preserving its activity, which seems to be particularly fragile in fungus, are discussed. Resolution of the constitutive enzymes was attempted and permitted the identification of the three protein bands resolved on SDS-polyacrylamide gel electrophoresis as E3, E1 and E2 with respective Mr values of 54,000, 53,000 and 49,000. Catalytic properties of the purified complex were established showing the importance of divalent cations in regulating the activity level. The role of Ca2+ in particular was investigated. It was shown that Ca2+ diminishes the Km value of the N. crassa alpha-ketoglutarate dehydrogenase complex for alpha-ketoglutarate in the physiological concentration range, as previously observed for the mammalian complexes.

Measurement of natural radioactivity in chemical fertilizer and agricultural soil: evidence of high alpha activity.

PubMed

Ghosh, Dipak; Deb, Argha; Bera, Sukumar; Sengupta, Rosalima; Patra, Kanchan Kumar

2008-02-01

People are exposed to ionizing radiation from the radionuclides that are present in different types of natural sources, of which phosphate fertilizer is one of the most important sources. Radionuclides in phosphate fertilizer belonging to 232Th and 238U series as well as radioisotope of potassium (40K) are the major contributors of outdoor terrestrial natural radiation. The study of alpha activity in fertilizers, which is the first ever in West Bengal, has been performed in order to determine the effect of the use of phosphate fertilizers on human health. The data have been compared with the alpha activity of different types of chemical fertilizers. The measurement of alpha activity in surface soil samples collected from the cultivated land was also performed. The sampling sites were randomly selected in the cultivated land in the Midnapore district, which is the largest district in West Bengal. The phosphate fertilizer is widely used for large agricultural production, mainly potatoes. The alpha activities have been measured using solid-state nuclear track detectors (SSNTD), a very sensitive detector for alpha particles. The results show that alpha activity of those fertilizer and soil samples varies from 141 Bq/kg to 2,589 Bq/kg and from 109 Bq/kg to 660 Bq/kg, respectively. These results were used to estimate environmental radiation exposure on human health contributed by the direct application of fertilizers.

A systematic review of the role of vitamin insufficiencies and supplementation in COPD

PubMed Central

2010-01-01

Background Pulmonary inflammation, oxidants-antioxidants imbalance, as well as innate and adaptive immunity have been proposed as playing a key role in the development of COPD. The role of vitamins, as assessed either by food frequency questionnaires or measured in serum levels, have been reported to improve pulmonary function, reduce exacerbations and improve symptoms. Vitamin supplements have therefore been proposed to be a potentially useful additive to COPD therapy. Methods A systematic literature review was performed on the association of vitamins and COPD. The role of vitamin supplements in COPD was then evaluated. Conclusions The results of this review showed that various vitamins (vitamin C, D, E, A, beta and alpha carotene) are associated with improvement in features of COPD such as symptoms, exacerbations and pulmonary function. High vitamin intake would probably reduce the annual decline of FEV1. There were no studies that showed benefit from vitamin supplementation in improved symptoms, decreased hospitalization or pulmonary function. PMID:21134250

Mechanical stimulation of skeletal muscle mitigates glucocorticoid induced decreases in prostaglandin synthesis

NASA Technical Reports Server (NTRS)

Chromiak, Joseph A.; Vandenburgh, Herman H.

1993-01-01

The glucocorticoid dexamethasone (Dex) induces a decline in protein synthesis and protein content of tissue cultured, avian skeletal muscle cells, and this atrophy is attenuated by repetitive mechanical stretch. Since the prostaglandin synthesis inhibitor indomethacin mitigated this stretch attenuation of muscle atrophy, the role of prostaglandins as growth modulators in these processes was examined. Dex at 10(exp -8) M reduced PGF(sub 2(alpha)) production 55 percent - 65 percent and PGE(sub 2) production 84 - 90 percent after 24 - 72 h of incubation in static cultures. Repetitive 10 percent stretch-relaxations of the non-Dex treated cultures increased PGF(sub 2(alpha)) efflux 41 percent at 24 h and 276 percent at 72 h and increased PGE(sub 2) production 51 percent at 24 h and 236 percent at 72 h. Mechanical stimulation of Dex treated cultures increased PGF(sub 2(alpha)) production 162 percent after 24 h, thus returning PGF(sub 2(alpha)) efflux to the level of non-Dex treated cultures. At 72 h, stretch increased PGF(sub 2(alpha)) efflux 65 percent in Dex treated cultures, but PGF(sub 2(alpha)) production was 45-84 percent less than non-Dex treated cultures. Mechanical stimulation of Dex treated cultures increased PGE(sub 2) production at 24 h, but not at 72 h. Dex reduced prostaglandin H synthase (PGHS) activity in the muscle cultures by 70 percent after 8 - 24 h of incubation, and mechanical stimulation increased PGHS activity of the Dex treated cultures by 98 percent. It is concluded that repetitive mechanical stimulation attenuates the catabolic effects of Dex on cultured skeletal muscle cells in part by reversing the Dex-induced declines in PGHS activity and prostaglandin production.

Virus/allergen interactions in asthma.

PubMed

Gavala, Monica L; Bashir, Hiba; Gern, James E

2013-06-01

Understanding the underlying mechanisms that cause and exacerbate allergic asthmatic disease is of great clinical interest. Clinical studies have revealed that allergies and viral respiratory illnesses are strongly linked to the inception and exacerbation of asthma, and suggest the possibility that there are interactive inflammatory mechanisms. Recent work has revealed a number of mechanisms of virus and allergen cross-talk that may play a role in the pathophysiology of allergic asthma, including (1) deficiency in virus-induced interferon responses, (2) defective epithelial barrier function, (3) increased release of epithelium-derived cytokines (e.g., thymic stromal lymphopoietin (TSLP), interleukin (IL)-25, IL-33), (4) dysregulation of lymphocytes [e.g., innate lymphoid cells (ILCs), regulatory T cells (Tregs)], and (5) altered activation of purinergic receptors. One or more of these processes may provide targets for new therapeutics to treat allergic asthma and prevent disease exacerbation.

The influence of tumour necrosis factor-alpha on the cardiovascular system of anaesthetized rats.

PubMed

Tabrizchi, R

2001-03-01

The effects of two vasoactive agents (adenosine A2A agonist, CGS 21680, and adrenoceptor agonist, noradrenaline) were examined on cardiac output (CO), heart rate (HR), blood pressure (BP), mean circulatory filling pressure (Pmcf), resistance to venous return, arterial resistance, dP/dt, plasma levels of NO2-/NO3-, and inducible nitric oxide synthase (iNOS) activity in lungs ex vivo, following treatment with tumour necrosis factor-alpha (TNF-alpha; 30 microg/kg) in anaesthetized rats. Treatment with TNF-alpha produced significant reduction in CO (41+/-2%), dP/dt (26+/-3%), BP (26+/-2%) and Pmcf (27+/-4%; n=6; mean+/-SEM), but increased arterial resistance. There were no significant changes in the plasma levels of NO2-/NO3-levels over time following treatment with TNF-alpha, but there was a significant increase (approximately twofold) in the activity of the iNOS in the lungs of animals treated with TNF-alpha. Administration of CGS 21680 (1.0 microg/kg per min) significantly increased CO (44+/-6%), HR (12+/-2%), Pmcf (24+/-4%) and dP/dt (24+/-5%) in TNF-alpha-treated rats. CGS 21680 also significantly reduced arterial resistance (33+/-2%) without altering resistance to venous return in TNF-alpha-treated rats. While noradrenaline (1.0 microg/kg per min) infusion did not significantly increase CO, it did significantly increase HR (12+/-1%), BP (55+/-9%), Pmcf (47+/-5%), dP/dt (65+/-7%), resistance to venous return (64+/-20%), and arterial resistance (41+/-16%) in TNF-alpha-treated animals. The reduction in BP due to administration of TNF-alpha is the result of significant reduction in CO. Consequently, the decline in CO can be attributed to a combination of a negative inotropic effect as well as a reduction in Pmcf. It is evident that infusion with CGS 21680 could reverse the negative impact of TNF-alpha on CO by increasing dP/dt, Pmcf and HR as well as a reduction in arterial resistance. The fact that noradrenaline did not significantly increase CO in TNF-alpha-treated rats can be attributed to increased arterial resistance as well increase in resistance to venous return.

Effects of 2G and 3G mobile phones on human alpha rhythms: Resting EEG in adolescents, young adults, and the elderly.

PubMed

Croft, R J; Leung, S; McKenzie, R J; Loughran, S P; Iskra, S; Hamblin, D L; Cooper, N R

2010-09-01

The present study was conducted to determine whether adolescents and/or the elderly are more sensitive to mobile phone (MP)-related bioeffects than young adults, and to determine this for both 2nd generation (2G) GSM, and 3rd generation (3G) W-CDMA exposures. To test this, resting alpha activity (8-12 Hz band of the electroencephalogram) was assessed because numerous studies have now reported it to be enhanced by MP exposure. Forty-one 13-15 year olds, forty-two 19-40 year olds, and twenty 55-70 year olds were tested using a double-blind crossover design, where each participant received Sham, 2G and 3G exposures, separated by at least 4 days. Alpha activity, during exposure relative to baseline, was recorded and compared between conditions. Consistent with previous research, the young adults' alpha was greater in the 2G compared to Sham condition, however, no effect was seen in the adolescent or the elderly groups, and no effect of 3G exposures was found in any group. The results provide further support for an effect of 2G exposures on resting alpha activity in young adults, but fail to support a similar enhancement in adolescents or the elderly, or in any age group as a function of 3G exposure. 2010 Wiley-Liss, Inc.

Regulation of PGE2 signaling pathways and TNF-alpha signaling pathways on the function of bone marrow-derived dendritic cells and the effects of CP-25.

PubMed

Li, Ying; Sheng, Kangliang; Chen, Jingyu; Wu, Yujing; Zhang, Feng; Chang, Yan; Wu, Huaxun; Fu, Jingjing; Zhang, Lingling; Wei, Wei

2015-12-15

This study was to investigate PGE2 and TNF-alpha signaling pathway involving in the maturation and activation of bone marrow dendritic cells (DCs) and the effect of CP-25. Bone marrow DCs were isolated and stimulated by PGE2 and TNF-alpha respectively. The markers of maturation and activation expressed on DCs, such as CD40, CD80, CD83, CD86, MHC-II, and the ability of antigen uptake of DCs were analyzed by flow cytometry. The proliferation of T cells co-cultured with DCs, the signaling pathways of PGE2-EP4-cAMP and TNF-alpha-TRADD-TRAF2-NF-κB in DCs were analyzed. The results showed that both PGE2 and TNF-alpha up-regulated the expressions of CD40, CD80, CD83, CD86, and MHC-II, decreased the antigen uptake of DCs, and DCs stimulated by PGE2 or TNF-alpha could increase T cell proliferation. CP-25 (10(-5), 10(-6), and 10(-7)mol/l) decreased significantly the expressions of CD40, CD80, CD83, CD86 and MHC-II, increased the antigen uptake of DCs, and suppressed T cell proliferation induced by DCs. PGE2 increased the expressions of EP4, NF-κB and down-regulated cAMP level of DCs. TNF-alpha could also up-regulate TNFR1, TRADD, TRAF2, and NF-κB expression of DCs. CP-25 (10(-5), 10(-6), and 10(-7)mol/l) decreased the expressions of EP4 and NF-κB, increased cAMP level in DCs stimulated by PGE2. CP-25 (10(-5), 10(-6), and 10(-7)mol/l) also could down-regulate significantly TNFR1, TRADD, TRAF2, and NF-κB expression in DCs stimulated by TNF-alpha. These results demonstrate that PGE2 and TNF-alpha could enhance DCs functions by mediating PGE2-EP4-cAMP pathway, TNF-alpha-TNFR1-TRADD-TRAF2-NF-κB pathway respectively. CP-25 might inhibit the function of DCs through regulating PGE2-EP4-cAMP and TNF-alpha-TNFR1-TRADD-TRAF2-NF-κB pathways. Copyright © 2015 Elsevier B.V. All rights reserved.

Structure of isocitrate dehydrogenase with alpha-ketoglutarate at 2.7-A resolution: conformational changes induced by decarboxylation of isocitrate.

PubMed

Stoddard, B L; Koshland, D E

1993-09-14

The structure of the isocitrate dehydrogenase (IDH) complex with bound alpha-ketoglutarate, Ca2+, and NADPH was solved at 2.7-A resolution. The alpha-ketoglutarate binds in the active site at the same position and orientation as isocitrate, with a difference between the two bound molecules of about 0.8 A. The Ca2+ metal is coordinated by alpha-ketoglutarate, three conserved aspartate residues, and a pair of water molecules. The largest motion in the active site relative to the isocitrate enzyme complex is observed for tyrosine 160, which originally forms a hydrogen bond to the labile carboxyl group of isocitrate and moves to form a new hydrogen bond to Asp 307 in the complex with alpha-ketoglutarate. This triggers a number of significant movements among several short loops and adjoining secondary structural elements in the enzyme, most of which participate in dimer stabilization and formation of the active-site cleft. These rearrangements are similar to the ligand-binding-induced movements observed in globins and insulin and serve as a model for an enzymatic mechanism which involves local shifts of secondary structural elements during turnover, rather than large-scale domain closures or loop transitions induced by substrate binding such as those observed in hexokinase or triosephosphate isomerase.

Generalised pustular psoriasis induced by cyclosporin a withdrawal responding to the tumour necrosis factor alpha inhibitor etanercept.

PubMed

Kamarashev, J; Lor, P; Forster, A; Heinzerling, L; Burg, G; Nestle, F O

2002-01-01

We report a 50-year-old male patient with a 15-year history of psoriasis including mutilating psoriatic arthritis, in whom the withdrawal of cyclosporin A induced a generalised pustular exacerbation and a aggravation of the joint condition. Two weekly injections of 25 mg of the tumour necrosis factor alpha inhibitor etanercept led to a rapid improvement of his psoriatic arthritis, as well as regression of the pustular eruption, while residual erythema was still present. The clinical response was reflected by an increase in circulating interleukin (IL) 10 and a decrease in IL-6 and IL-8 serum levels during treatment. We conclude that etanercept may be a safe and effective therapy not only in severe psoriatic arthritis, but also in cases of pustular rebound after withdrawal of immunosuppressive agents. Copyright 2002 S. Karger AG, Basel

Thiols in the alphaIIbbeta3 integrin are necessary for platelet aggregation.

PubMed

Manickam, Nagaraj; Sun, Xiuhua; Hakala, Kevin W; Weintraub, Susan T; Essex, David W

2008-07-01

Sulfhydryl groups of platelet surface proteins are important in platelet aggregation. While p-chloromercuribenzene sulphonate (pCMBS) has been used in most studies on platelet surface thiols, the specific thiol-proteins that pCMBS reacts with to inhibit aggregation have not been well defined. Since the thiol-containing P2Y(12) ADP receptor is involved in most types of platelet aggregation, we used the ADP scavenger apyrase and the P2Y(12) receptor antagonist 2-MeSAMP to examine thiol-dependent reactions in the absence of contributions from this receptor. We provide evidence for a non-P2Y(12) thiol-dependent reaction near the final alphaIIbbeta3-dependent events of aggregation. We then used 3-(N-maleimidylpropionyl)biocytin (MPB) and pCMBS to study thiols in alphaIIbbeta3. As previously reported, disruption of the receptor was required to obtain labelling of thiols with MPB. Specificity of labelling for thiols in the alphaIIb and beta3 subunits was confirmed by identification of the purified proteins by mass spectrometry and by inhibition of labelling with 5,5'-dithiobis-(2-nitrobenzoic acid). In contrast to MPB, pCMBS preferentially reacted with thiols in alphaIIbbeta3 and blocked aggregation under physiological conditions. Similarly, pCMBS preferentially inhibited signalling-independent activation of alphaIIbbeta3 by Mn(2+). Our results suggest that the thiols in alphaIIbbeta3 that are blocked by pCMBS are important in the activation of this integrin.

TNF-{alpha} mediates the stimulation of sclerostin expression in an estrogen-deficient condition

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

Kim, Beom-Jun; Bae, Sung Jin; Lee, Sun-Young

Highlights: Black-Right-Pointing-Pointer Estrogen deprivation stimulates the bony sclerostin levels with reversal by estrogen. Black-Right-Pointing-Pointer TNF-{alpha} increases the activity and expression of MEF2 in UMR-106 cells. Black-Right-Pointing-Pointer TNF-{alpha} blocker prevents the stimulation of bony sclerostin expression by ovariectomy. Black-Right-Pointing-Pointer No difference in bony sclerostin expression between sham-operated and ovariectomized nude mice. -- Abstract: Although recent clinical studies have suggested a possible role for sclerostin, a secreted Wnt antagonist, in the pathogenesis of postmenopausal osteoporosis, the detailed mechanisms how estrogen deficiency regulates sclerostin expression have not been well-elucidated. Bilateral ovariectomy or a sham operation in female C57BL/6 mice and BALB/c nude micemore » was performed when they were seven weeks of age. The C57BL/6 mice were intraperitoneally injected with phosphate-buffered serum (PBS), 5 {mu}g/kg {beta}-estradiol five times per week for three weeks, or 10 mg/kg TNF-{alpha} blocker three times per week for three weeks. Bony sclerostin expression was assessed by immunohistochemistry staining in their femurs. The activity and expression of myocyte enhancer factors 2 (MEF2), which is essential for the transcriptional activation of sclerostin, in rat UMR-106 osteosarcoma cells were determined by luciferase reporter assay and western blot analysis, respectively. Bony sclerostin expression was stimulated by estrogen deficiency and it was reversed by estradiol supplementation. When the UMR-106 cells were treated with well-known, estrogen-regulated cytokines, only TNF-{alpha}, but not IL-1 and IL-6, increased the MEF2 activity. Consistently, TNF-{alpha} also increased the nuclear MEF2 expression. Furthermore, the TNF-{alpha} blocker prevented the stimulation of bony sclerostin expression by ovariectomy. We also found that there was no difference in sclerostin expression between ovariectomized nude mice and sham-operated nude mice. In conclusion, these results suggest that TNF-{alpha} originating from T cells may be at least in part responsible for stimulating the sclerostin expression observed in an estrogen-deficient condition.« less

Induction of hypoxia-inducible factor-1alpha and activation of caspase-3 in hypoxia-reoxygenated bone marrow stroma is negatively regulated by the delayed production of substance P.

PubMed

Qian, J; Ramroop, K; McLeod, A; Bandari, P; Livingston, D H; Harrison, J S; Rameshwar, P

2001-10-15

The bone marrow (BM), which is the major site of immune cell development in the adult, responds to different stimuli such as inflammation and hemorrhagic shock. Substance P (SP) is the major peptide encoded by the immune/hemopoietic modulator gene, preprotachykinin-1 (PPT-I). Differential gene expression using a microarray showed that SP reduced hypoxia-inducible factor-1alpha (HIF-1alpha) mRNA levels in BM stroma. Because long-term hypoxia induced the expression of PPT-I in BM mononuclear cells, we used timeline studies to determine whether PPT-I is central to the biologic responses of BM stroma subjected to 30-min hypoxia (pO(2) = 35 mm Hg) followed by reoxygenation. HIF-1alpha mRNA and protein levels were increased up to 12 h. At this time, beta-PPT-I mRNA was detected with the release of SP at 16 h. SP release correlated with down-regulation of HIF-1alpha to baseline. A direct role for SP in HIF-1alpha expression was demonstrated as follows: 1) transient knockout of beta-PPT-I showed an increase in HIF-1alpha expression up to 48 h of reoxygenation; and 2) HIF-1alpha expression remained baseline during reoxygenation when stroma was subjected to hypoxia in the presence of SP. Reoxygenation activated the PPT-I promoter with concomitant nuclear translocation of HIF-1alpha that can bind to the respective consensus sequences within the PPT-I promoter. SP reversed active caspase-3, an indicator of apoptosis and erythropoiesis, to homeostasis level after reoxygenation of hypoxic stroma. The results show that during reoxgenation the PPT-I gene acts as a negative regulator on the expression of HIF-1alpha and active caspase-3 in BM stroma subjected to reoxygenation.

The TWIST1 oncogene is a direct target of hypoxia-inducible factor-2alpha.

PubMed

Gort, E H; van Haaften, G; Verlaan, I; Groot, A J; Plasterk, R H A; Shvarts, A; Suijkerbuijk, K P M; van Laar, T; van der Wall, E; Raman, V; van Diest, P J; Tijsterman, M; Vooijs, M

2008-03-06

Hypoxia-inducible factors (HIFs) are highly conserved transcription factors that play a crucial role in oxygen homeostasis. Intratumoral hypoxia and genetic alterations lead to HIF activity, which is a hallmark of solid cancer and is associated with poor clinical outcome. HIF activity is regulated by an evolutionary conserved mechanism involving oxygen-dependent HIFalpha protein degradation. To identify novel components of the HIF pathway, we performed a genome-wide RNA interference screen in Caenorhabditis elegans, to suppress HIF-dependent phenotypes, like egg-laying defects and hypoxia survival. In addition to hif-1 (HIFalpha) and aha-1 (HIFbeta), we identified hlh-8, gska-3 and spe-8. The hlh-8 gene is homologous to the human oncogene TWIST1. We show that TWIST1 expression in human cancer cells is enhanced by hypoxia in a HIF-2alpha-dependent manner. Furthermore, intronic hypoxia response elements of TWIST1 are regulated by HIF-2alpha, but not HIF-1alpha. These results identify TWIST1 as a direct target gene of HIF-2alpha, which may provide insight into the acquired metastatic capacity of hypoxic tumors.

RACK1 binds to Smad3 to modulate transforming growth factor-beta1-stimulated alpha2(I) collagen transcription in renal tubular epithelial cells.

PubMed

Okano, Kazuhiro; Schnaper, H William; Bomsztyk, Karol; Hayashida, Tomoko

2006-09-08

Although it is clear that transforming growth factor-beta1 (TGF-beta1) is critical for renal fibrogenesis, the complexity of the involved mechanisms is increasingly apparent. TGF-beta1 stimulates phosphorylation of Smad2/3 and activates other signaling molecules as well. The molecular link between these other kinases and Smads is not known. We sought new binding partners for Smad3 in renal cells and identified receptor for activated protein kinase C 1 (RACK1) as a novel binding partner of Smad3. The linker region of Smad3 and the tryptophan-aspartic acid repeat 6 and 7 of RACK1 are sufficient for the association. RACK1 also interacts with Smad3 in the human kidney epithelial cell line, HKC. Silencing RACK1 increases transcriptional activity of TGF-beta1-responsive promoter sequences of the Smad binding element (SBE), p3TP-Lux, and alpha2(I) collagen. Conversely, overexpressed RACK1 negatively modulates alpha2(I) collagen transcriptional activity in TGF-beta1-stimulated cells. RACK1 did not affect phosphorylation of Smad3 at the C terminus or in the linker region. However, RACK1 reduced direct binding of Smad3 to the SBE motif. Mutating a RACK1 tyrosine at residue 246, but not at 228, decreased the inhibitory effect of RACK1 on both alpha2(I) collagen promoter activity and Smad binding to SBE induced by TGF-beta1. These results suggest that RACK1 modulates transcription of alpha2(I) collagen by TGF-beta1 through interference with Smad3 binding to the gene promoter.

Transcriptional co-activator PGC-1 alpha drives the formation of slow-twitch muscle fibres.

PubMed

Lin, Jiandie; Wu, Hai; Tarr, Paul T; Zhang, Chen-Yu; Wu, Zhidan; Boss, Olivier; Michael, Laura F; Puigserver, Pere; Isotani, Eiji; Olson, Eric N; Lowell, Bradford B; Bassel-Duby, Rhonda; Spiegelman, Bruce M

2002-08-15

The biochemical basis for the regulation of fibre-type determination in skeletal muscle is not well understood. In addition to the expression of particular myofibrillar proteins, type I (slow-twitch) fibres are much higher in mitochondrial content and are more dependent on oxidative metabolism than type II (fast-twitch) fibres. We have previously identified a transcriptional co-activator, peroxisome-proliferator-activated receptor-gamma co-activator-1 (PGC-1 alpha), which is expressed in several tissues including brown fat and skeletal muscle, and that activates mitochondrial biogenesis and oxidative metabolism. We show here that PGC-1 alpha is expressed preferentially in muscle enriched in type I fibres. When PGC-1 alpha is expressed at physiological levels in transgenic mice driven by a muscle creatine kinase (MCK) promoter, a fibre type conversion is observed: muscles normally rich in type II fibres are redder and activate genes of mitochondrial oxidative metabolism. Notably, putative type II muscles from PGC-1 alpha transgenic mice also express proteins characteristic of type I fibres, such as troponin I (slow) and myoglobin, and show a much greater resistance to electrically stimulated fatigue. Using fibre-type-specific promoters, we show in cultured muscle cells that PGC-1 alpha activates transcription in cooperation with Mef2 proteins and serves as a target for calcineurin signalling, which has been implicated in slow fibre gene expression. These data indicate that PGC-1 alpha is a principal factor regulating muscle fibre type determination.

Antioxidative characteristics and inhibition of alpha-melanocyte-stimulating hormone-stimulated melanogenesis of vanillin and vanillic acid from Origanum vulgare.

PubMed

Chou, Tzung-Han; Ding, Hsiou-Yu; Hung, Wei Jing; Liang, Chia-Hua

2010-08-01

The antioxidant activities of vanillin and vanillic acid isolated from Origanum vulgare are investigated. These compounds may serve as agents for antimelanogenesis. Vanillic acid is a stronger antioxidant than vanillin, in terms of free radical scavenging activity, reducing power and inhibition of lipid peroxidation. The inhibition of cellular reactive oxygen species (ROS) in H(2)O(2)-treated BNLCL2 cells by vanillic acid exceeds that of ascorbic acid (AA) or trolox. In B16F0 cells stimulated with alpha-melanocyte-stimulating hormone (alpha-MSH), vanillic acid reduced cellular tyrosinase activity, DOPA oxidase and melanin contents, as well as down-regulated expressions of melanocortin-1 receptor (MC1R), microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related proteins 2 (TRP-2) and TRP-1. Vanillin did not express inhibition of tyrosinase activity. These results supported that vanillic acid is a significantly stronger antioxidant than vanillin and exhibited stronger antimelanogenesis performance because of the structural presence of the carboxyl group.

The development of a modified human IFN-alpha2b linked to the Fc portion of human IgG1 as a novel potential therapeutic for the treatment of hepatitis C virus infection.

PubMed

Jones, Tim D; Hanlon, Marian; Smith, Beverley J; Heise, Charles T; Nayee, Prakash D; Sanders, Deborah A; Hamilton, Anita; Sweet, Clive; Unitt, Esther; Alexander, Graeme; Lo, Kin-Ming; Gillies, Stephen D; Carr, Frank J; Baker, Matthew P

2004-09-01

Interferon-alpha (IFN-alpha), in conjunction with ribavirin, is the current standard for the treatment of chronic hepatitis C virus (HCV) infection. This treatment requires frequent dosing, with a significant risk of the development of anti-IFN-alpha neutralizing antibodies that correlates with lack of efficacy or relapse. We have developed an IFN-alpha linked to the Fc region of human IgG1 for improved half-life and less frequent dosing. We have also identified, using a human T cell proliferation assay, three regions of IFN-alpha2b that are potentially immunogenic, and a variant containing a total of six mutations within these regions was made. This variant was made as a fusion to Fc either with or without a flexible linker between the fusion partners. Both configurations of the variant were less active than native IFN-alpha alone, although the variant containing the flexible linker had in vitro antiviral activity within the range of other modified IFN-alphas currently in clinical use. Peptides spanning the modified regions were tested in T cell proliferation assays and found to be less immunogenic than native controls when using peripheral blood mononuclear cells (PBMCs) from both healthy individuals and HCV-infected patients who had been treated previously with IFN-alpha2b. Copyright Mary Ann Liebert, Inc.

TNF-alpha-induced c-Fos generation in the nucleus of the solitary tract is blocked by NBQX and MK-801.

PubMed

Emch, G S; Hermann, G E; Rogers, R C

2001-11-01

Previous studies have shown that identified neurons of the nucleus of the solitary tract (NST) are excited by the cytokine tumor necrosis factor-alpha (TNF-alpha). Vagal afferent connections with the NST are predominantly glutaminergic. Therefore, we hypothesized that TNF-alpha effects on NST neurons may be via modulation of glutamate neurotransmission. The present study used activation of the immediate early gene product c-Fos as a marker for neuronal activation in the NST. c-Fos expression was evaluated after microinjections of TNF-alpha in the presence or absence of either the alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor antagonist 1,2,3,4-tetrahydro-6-nitro-2,3-dioxo-benzo[f]quinoxaline-7-sulfonamide disodium (NBQX) or the N-methyl-D- aspartate (NMDA) antagonist MK-801. To assess the specificity of the interaction between TNF-alpha and glutamate, c-Fos expression was also evaluated after injection of oxytocin (OT) (which has a direct excitatory effect in this area of the brain stem) in the presence and absence of NBQX or MK-801. c-Fos labeling was significantly increased in the NST after TNF-alpha exposure. Coinjection of either NBQX or MK-801 with TNF-alpha prevented significant c-Fos induction in the NST. Microinjections of OT also induced significant NST c-Fos elevation, but this expression was unaffected by coinjection of either antagonist with OT. These data lead us to conclude that TNF-alpha activation of NST neurons depends on glutamate and such an interaction is not generalized to all agonists that act on the NST.

Intracellular signaling required for CCL25-stimulated T cell adhesion mediated by the integrin alpha4beta1.

PubMed

Parmo-Cabañas, Marisa; García-Bernal, David; García-Verdugo, Rosa; Kremer, Leonor; Márquez, Gabriel; Teixidó, Joaquin

2007-08-01

The alpha4beta1 integrin is expressed on thymocytes and mediates cell attachment to its ligands CS-1/fibronectin (CS-1/FN) and VCAM-1 in the thymus. The chemokine CCL25 is highly expressed in the thymus, where it binds to its receptor CCR9 on thymocytes promoting migration and activation. We show here that alpha4beta1 and CCR9 are coexpressed mainly on double- and single-positive thymocytes and that CCL25 strongly stimulates CD4(+)CD8(+) and CD4(+)CD8(-) adhesion to CS-1/FN and VCAM-1. CCL25 rapidly activated the GTPases Rac and Rap1 on thymocytes, and this activation was required for stimulation of adhesion, as detected using the CCR9(+)/alpha4beta1(+) human T cell line Molt-4. To study the role on CCL25-stimulated adhesion of the Rac downstream effector Wiskott-Aldrich syndrome protein family verproline-homologous protein 2 (WAVE2) as well as of Rap1-GTP-interacting proteins, regulator of adhesion and cell polarization enriched in lymphoid tissues (RAPL) and Rap1-GTP-interacting adapter molecule (RIAM), we knocked down their expression and tested transfectant attachment to alpha4beta1 ligands. We found that WAVE2 and RAPL but not RIAM were required for efficient triggering by CCL25 of T cell adhesion to CS-1/FN and VCAM-1. Although Rac and Rap1 activation was required during early steps of T cell adhesion stimulated by CCL25, WAVE2 was needed for the development of actin-dependent T cell spreading subsequent to adhesion strengthening but not during initial alpha4beta1-ligand interactions. These results suggest that regulation by CCL25 of adhesion of thymocyte subpopulations mediated by alpha4beta1 could contribute to control their trafficking in the thymus during maturation, and identify Rac-WAVE2 and Rap1-RAPL as pathways whose activation is required in inside-out signaling, leading to stimulated adhesion.

Effects of estradiol, estrogen receptor subtype-selective agonists and genistein on glucose metabolism in leptin resistant female Zucker diabetic fatty (ZDF) rats.

PubMed

Weigt, Carmen; Hertrampf, Torsten; Flenker, Ulrich; Hülsemann, Frank; Kurnaz, Pinar; Fritzemeier, Karl Heinrich; Diel, Patrick

2015-11-01

The leptin resistant Zucker diabetic fatty (ZDF) rats are hyperphagic and become obese, but whereas the males develop type 2 diabetes mellitus (T2DM), the females remain euglycaemic. As estrogen deficiency is known to increase the risk of developing T2DM, we evaluated the role of ER subtypes alpha and beta in the development of glucose tolerance in leptin resistant ovariectomized (OVX) ZDF rats. At least six rats per group were treated with either vehicle (OVX), 17β-estradiol (E2), ER subtype-selective agonists (Alpha and Beta), or genistein (Gen) for 17 weeks. At the end of the treatment period a glucose tolerance assay was performed and the metabolic flux of (13)C-glucose for the E2 group was investigated. OVX ZDF rats treated with E2, Alpha, Beta, and Gen tolerated the glucose significantly better than untreated controls. E2 treatment increased absorbance/flux of (13)C-glucose to metabolic relevant tissues such liver, adipose tissue, gastrocnemius, and soleus muscle. Moreover, whereas Alpha treatment markedly increased mRNA expression of GLUT4 in gastrocnemius muscle, Beta treatment resulted in the largest fiber sizes of the soleus muscle. Treatment with Gen increased both the mRNA expression of GLUT 4 and the fiber sizes in the skeletal muscle. In addition, E2 and Alpha treatment decreased food intake and body weight gain. In summary, estrogen-improved glucose absorption is mediated via different molecular mechanisms: while activation of ER alpha seems to stimulate muscular GLUT4 functionality, activation of ER beta results in a hypertrophy of muscle fibers. In addition, selective activation of ER alpha decreased food intake and body weight gain. Our data further indicate that ER subtype-selective agonists and genistein improve systemic glucose tolerance also in the absence of a functional leptin signaling pathway. Copyright © 2015 Elsevier Ltd. All rights reserved.

Function of Several Critical Amino Acids in Human Pyruvate Dehydrogenase Revealed by Its Structure

NASA Technical Reports Server (NTRS)

Korotchkina, Lioubov G.; Ciszak, E.; Patel, M.

2004-01-01

Pyruvate dehydrogenase (E1), an alpha 2 beta 2 tetramer, catalyzes the oxidative decarboxylation of pyruvate and reductive acetylation of lipoyl moieties of the dihydrolipoamide acetyltransferase. The roles of beta W135, alpha P188, alpha M181, alpha H15 and alpha R349 of E1 determined by kinetic analysis were reassessed by analyzing the three-dimensional structure of human E1. The residues identified above are found to play a structural role rather than being directly involved in catalysis: beta W135 is the center residue in the hydrophobic interaction between beta and beta' subunits; alpha P188 and alpha M181 are critical for the conformation of the TPP-binding motif and interaction between alpha and beta subunits; alpha H15, is necessary for the organization of the N-terminus of alpha and alpha'; subunits and alpha R349 supports the interaction of the C-terminus of the alpha subunits with the beta subunits. Analysis of several critical E1 residues confirms the importance of residues distant from the active site for subunit interactions and enzyme function.

Caplacizumab reduces the frequency of major thromboembolic events, exacerbations and death in patients with acquired thrombotic thrombocytopenic purpura.

PubMed

Peyvandi, F; Scully, M; Kremer Hovinga, J A; Knöbl, P; Cataland, S; De Beuf, K; Callewaert, F; De Winter, H; Zeldin, R K

2017-07-01

Essentials Acquired thrombotic thrombocytopenic purpura (aTTP) is linked with significant morbidity/mortality. Caplacizumab's effect on major thromboembolic (TE) events, exacerbations and death was studied. Fewer caplacizumab-treated patients had a major TE event, an exacerbation, or died versus placebo. Caplacizumab has the potential to reduce the acute morbidity and mortality associated with aTTP. Background Acquired thrombotic thrombocytopenic purpura (aTTP) is a life-threatening autoimmune thrombotic microangiopathy. In spite of treatment with plasma exchange and immunosuppression, patients remain at risk for thrombotic complications, exacerbations, and death. In the phase II TITAN study, treatment with caplacizumab, an anti-von Willebrand factor Nanobody ® was shown to reduce the time to confirmed platelet count normalization and exacerbations during treatment. Objective The clinical benefit of caplacizumab was further investigated in a post hoc analysis of the incidence of major thromboembolic events and exacerbations during the study drug treatment period and thrombotic thrombocytopenic purpura-related death during the study. Methods The Standardized Medical Dictionary for Regulatory Activities (MedDRA) Query (SMQ) for 'embolic and thrombotic events' was run to investigate the occurrence of major thromboembolic events and exacerbations in the safety population of the TITAN study, which consisted of 72 patients, of whom 35 received caplacizumab and 37 received placebo. Results Four events (one pulmonary embolism and three aTTP exacerbations) were reported in four patients in the caplacizumab group, and 20 such events were reported in 14 patients in the placebo group (two acute myocardial infarctions, one ischemic stroke, one hemorrhagic stroke, one pulmonary embolism, one deep vein thrombosis, one venous thrombosis, and 13 aTTP exacerbations). Two of the placebo-treated patients died from aTTP during the study. Conclusion In total, 11.4% of caplacizumab-treated patients and 43.2% of placebo-treated patients experienced one or more major thromboembolic events, experienced an exacerbation, or died. This analysis shows the potential for caplacizumab to reduce the risk of major thromboembolic morbidities and mortality associated with aTTP. © 2017 The Authors. Journal of Thrombosis and Haemostasis published by Wiley Periodicals, Inc. on behalf of International Society on Thrombosis and Haemostasis.

Measuring Disease Exacerbation and Flares in Rheumatoid Arthritis: Comparison of Commonly Used Disease Activity Indices and Individual Measures.

PubMed

Voshaar, Martijn A H Oude; Moghadam, Marjan Ghiti; Vonkeman, Harald E; Ten Klooster, Peter M; van Schaardenburg, Dirkjan; Tekstra, Janneke; Visser, Henk; van de Laar, Mart A F J; Jansen, Tim L

2017-08-01

To evaluate and compare the utility of commonly used outcome measures for assessing disease exacerbation or flare in patients with rheumatoid arthritis (RA). Data from the Dutch Potential Optimalisation of (Expediency) and Effectiveness of Tumor necrosis factor-α blockers (POET) study, in which 462 patients discontinued their tumor necrosis factor-α inhibitor, were used. The ability of different measures to discriminate between those with and without physician-reported flare or medication escalation at the 3-month visit (T2) was evaluated by calculating effect size (ES) statistics. Responsiveness to increased disease activity was compared between measures by standardizing change scores (SCS) from baseline to the 3-month visit. Finally, the incremental validity of individual outcome measures beyond the Simplified Disease Activity Score was evaluated using logistic regression analysis. The SCS were greater for disease activity indices than for any of the individual measures. The 28-joint Disease Activity Score, Clinical Disease Activity Index, and Simplified Disease Activity Index performed similarly. Pain and physician's (PGA) and patient's global assessment (PtGA) of disease activity were the most responsive individual measures. Similar results were obtained for discriminative ability, with greatest ES for disease activity indices followed by pain, PGA, and PtGA. Pain was the only measure to demonstrate incremental validity beyond SDAI in predicting 3-month flare status. These results support the use of composite disease activity indices, patient-reported pain and disease activity, and physician-reported disease activity for measuring disease exacerbation or identifying flares of RA. Physical function, acute-phase response, and the auxiliary measures fatigue, participation, and emotional well-being performed poorly.

Alpha 2-adrenoceptor blockade, pituitary-adrenal hormones, and agonistic interactions in rats.

PubMed

Haller, J; Barna, I; Kovács, J L

1994-08-01

The effects of adrenergic activation on aggressiveness and the aggression induced endocrine changes were tested in rats. Alpha 2 adrenoceptor blockers were used for enhancing activation of the adrenergic system, and changes in aggressiveness were tested in resident-intruder contests. Three experiments were conducted. In experiment 1, saline injected rats responded to the presence of an opponent by aggression and the increase in plasma ACTH and corticosterone. Intraperitoneal administration of 1 mg/kg CH-38083 (an alpha 2 adrenoceptor antagonist) produced a several fold increase in clinch fighting and mutual upright scores, and also further enhanced the plasma ACTH and corticosterone response. In experiment 2, the effect of three doses (0.5, 1 and 2 mg/kg) of three different alpha 2 adrenoceptor blockers CH-38083, idazoxan and yohimbine were tested. All the substances increased aggression at 0.5 and 1 mg/kg; at 2 mg/kg the effect of idazoxan and yohimbine disappeared, while with CH-38083 an additional increase was obtained. In yohimbine treated animals the enhancement of aggression was reduced already at 1 mg/kg. In experiment 3, indomethacin, a potent inhibitor of the catecholamine-induced ACTH release completely abolished the effects of the alpha 2 adrenoceptor antagonist CH-38083: the intensity of agonistic interactions, as well as ACTH and corticosterone plasma concentrations, returned to control levels. The possible role of catecholamines and the stress hormones in the activation of aggression is discussed.

Regulation of G-protein coupled receptor traffic by an evolutionary conserved hydrophobic signal.

PubMed

Angelotti, Tim; Daunt, David; Shcherbakova, Olga G; Kobilka, Brian; Hurt, Carl M

2010-04-01

Plasma membrane (PM) expression of G-protein coupled receptors (GPCRs) is required for activation by extracellular ligands; however, mechanisms that regulate PM expression of GPCRs are poorly understood. For some GPCRs, such as alpha2c-adrenergic receptors (alpha(2c)-ARs), heterologous expression in non-native cells results in limited PM expression and extensive endoplasmic reticulum (ER) retention. Recently, ER export/retentions signals have been proposed to regulate cellular trafficking of several GPCRs. By utilizing a chimeric alpha(2a)/alpha(2c)-AR strategy, we identified an evolutionary conserved hydrophobic sequence (ALAAALAAAAA) in the extracellular amino terminal region that is responsible in part for alpha(2c)-AR subtype-specific trafficking. To our knowledge, this is the first luminal ER retention signal reported for a GPCR. Removal or disruption of the ER retention signal dramatically increased PM expression and decreased ER retention. Conversely, transplantation of this hydrophobic sequence into alpha(2a)-ARs reduced their PM expression and increased ER retention. This evolutionary conserved hydrophobic trafficking signal within alpha(2c)-ARs serves as a regulator of GPCR trafficking.

Hepatic effects of a methionine-choline-deficient diet in hepatocyte RXR{alpha}-null mice

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

Gyamfi, Maxwell Afari; Tanaka, Yuji; He Lin

Retinoid X receptor-{alpha} (RXR{alpha}) is an obligate partner for several nuclear hormone receptors that regulate important physiological processes in the liver. In this study the impact of hepatocyte RXR{alpha} deficiency on methionine and choline deficient (MCD) diet-induced steatosis, oxidative stress, inflammation, and hepatic transporters gene expression were examined. The mRNA of sterol regulatory element-binding protein (SREBP)-regulated genes, important for lipid synthesis, were not altered in wild type (WT) mice, but were increased 2.0- to 5.4-fold in hepatocyte RXR{alpha}-null (H-RXR{alpha}-null) mice fed a MCD diet for 14 days. Furthermore, hepatic mRNAs and proteins essential for fatty acid {beta}-oxidation were not alteredmore » in WT mice, but were decreased in the MCD diet-fed H-RXR{alpha}-null mice, resulting in increased hepatic free fatty acid levels. Cyp2e1 enzyme activity and lipid peroxide levels were induced only in MCD-fed WT mice. In contrast, hepatic mRNA levels of pro-inflammatory factors were increased only in H-RXR{alpha}-null mice fed the MCD diet. Hepatic uptake transporters Oatp1a1 and Oatp1b2 mRNA levels were decreased in WT mice fed the MCD diet, whereas the efflux transporter Mrp4 was increased. However, in the H-RXR{alpha}-null mice, the MCD diet only moderately decreased Oatp1a1 and induced both Oatp1a4 and Mrp4 gene expression. Whereas the MCD diet increased serum bile acid levels and alkaline phosphatase activity in both WT and H-RXR{alpha}-null mice, serum ALT levels were induced (2.9-fold) only in the H-RXR{alpha}-null mice. In conclusion, these data suggest a critical role for RXR{alpha} in hepatic fatty acid homeostasis and protection against MCD-induced hepatocyte injury.« less

The role of heme oxygenase-1 in drug metabolizing dysfunction in the alcoholic fatty liver exposed to ischemic injury

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

Park, Sang Won; Kang, Jung-Woo; Lee, Sun-Mee, E-mail: sunmee@skku.edu

This study was designed to investigate the role of heme oxygenase-1 (HO-1) in hepatic drug metabolizing dysfunction after ischemia/reperfusion (IR) in alcoholic fatty liver (AFL). Rats were fed a Lieber–DeCarli diet for five weeks to allow for development of AFL and were then subjected to 90 min of hepatic ischemia and 5 h of reperfusion. Rats were pretreated with hemin (HO-1 inducer) or ZnPP (HO-1 inhibitor) for 16 h and 3 h before hepatic ischemia. After hepatic IR, ethanol diet (ED)-fed rats had higher serum aminotransferase activities and more severe hepatic necrosis compared to the control diet (CD)-fed rats. Thesemore » changes were attenuated by hemin and exacerbated by ZnPP. The activity and gene expression of HO-1 and its transcription factor (Nrf2) level increased significantly after 5 h of reperfusion in CD-fed rats but not in ED-fed rats. After reperfusion, cytochrome P450 (CYP) 1A1, 1A2, and 2B1 activities were reduced to levels lower than those observed in sham group, whereas CYP2E1 activity increased. The decrease in CYP2B1 activity and the increase in CYP2E1 activity were augmented after hepatic IR in ED-fed animals. These changes were significantly attenuated by hemin but aggravated by ZnPP. Finally, CHOP expression and PERK phosphorylation, microsomal lipid peroxidation, and levels of proinflammatory mediators increased in ED-fed rats compared to CD-fed rats after reperfusion. These increases were attenuated by hemin. Our results suggest that AFL exacerbates hepatic drug metabolizing dysfunction during hepatic IR via endoplasmic reticulum stress and lipid peroxidation and this is associated with impaired HO-1 induction. - Highlights: • Endogenous HO-1 is generated in insufficient quantities in steatotic ischemic injury. • Impaired HO-1 induction leads to excessive ER stress response and lipid peroxidation. • Alcoholic steatosis exacerbates IR-induced hepatic drug-metabolizing dysfunction. • HO-1 induction is required for appropriate medication in patients with steatosis.« less

Cyclooxygenase-2 promotes pulmonary intravascular macrophage accumulation by exacerbating BMP signaling in rat experimental hepatopulmonary syndrome.

PubMed

Liu, Chang; Gao, Jing; Chen, Bing; Chen, Lin; Belguise, Karine; Yu, Weifeng; Lu, Kaizhi; Wang, Xiaobo; Yi, Bin

2017-08-15

One central factor in hepatopulmonary syndrome (HPS) pathogenesis is intravascular accumulation of activated macrophages in small pulmonary arteries. However, molecular mechanism underlying the macrophage accumulation in HPS is unknown. In this study, we aimed to explore whether elevated COX-2 induces the Bone morphogenic protein-2 (BMP-2)/Crossveinless-2 (CV-2) imbalance and then activation of BMP signaling pathway promotes the macrophage accumulation in Common Bile Duct Ligation (CBDL) rat lung. The COX-2/PGE2 signaling activation, the BMP-2/CV-2 imbalance and the activation of Smad1 were evaluated in CBDL rat lung and in cultured pulmonary microvascular endothelial cells (PMVECs) under the HPS serum stimulation. The effects of Parecoxib (COX-2 inhibitor), BMP-2 and CV-2 recombinant proteins on 4-week CBDL rat lung were determined, respectively. The COX-2/PGE2 signaling pathway was activated in CBDL rat lung in vivo and PMVECs in vitro, which was due to the activation of NF-κB P65. The inhibition of COX-2 by Parecoxib reduced macrophage accumulation, decreased lung angiogenesis and improved HPS. Meanwhile, the CBDL rat lung secreted more BMP-2 but less CV-2, and the imbalance between BMP-2 and CV-2 exacerbated the BMP signaling activation thus promoting the macrophage accumulation and lung angiogenesis. The BMP-2/CV-2 imbalance is dependent on the COX-2/PGE2 signaling pathway, and thus the effects of this imbalance can be reversed by adminstration of Parecoxib. Our findings indicate that inhibition of COX-2 by parecoxib can improve the HPS through the repression of BMP signaling and macrophage accumulation. Copyright © 2017 Elsevier Inc. All rights reserved.

Temporal profile of prolonged, night-time driving performance: breaks from driving temporarily reduce time-on-task fatigue but not sleepiness.

PubMed

Phipps-Nelson, Jo; Redman, Jennifer R; Rajaratnam, Shantha M W

2011-09-01

Breaks are often used by drivers to counteract sleepiness and time-on-task fatigue during prolonged driving. We examined the temporal profile of changes in driving performance, electroencephalogram (EEG) activity and subjective measures of sleepiness and fatigue during prolonged nocturnal driving in a car simulator. In addition, the study examined the impact of regular breaks from driving on performance, sleepiness and fatigue. Healthy volunteers (n=12, 23-45 years) maintained a regular sleep-wake pattern for 14 days and were then in a laboratory from 21:00 to 08:30 hours. The driving simulator scene was designed to simulate monotonous night-time rural driving. Participants drove 4 × 2-h test sessions, with a break from driving of 1 h between each session. During the break participants performed tests assessing sleepiness and fatigue, and psychomotor performance (~30 mins), and then were permitted to sit quietly. They were monitored for wakefulness, and not permitted to nap or ingest caffeine. EEG was recorded during the driving task, and subjective assessments of sleepiness and fatigue were obtained at the start and completion of each session. We found that driving performance deteriorated (2.5-fold), EEG delta, theta and alpha activity increased, and subjective sleepiness and fatigue ratings increased across the testing period. Driving performance and fatigue ratings improved following the scheduled breaks from driving, while the breaks did not affect EEG activity and subjective sleepiness. Time-on-task effects increased through the testing period, indicating that these effects are exacerbated by increasing sleepiness. Breaks from driving without sleep temporarily ameliorate time-on-task fatigue, but provide little benefit to the sleepy driver. © 2010 European Sleep Research Society.

Alpha lipoic acid protects the heart against myocardial post ischemia-reperfusion arrhythmias via KATP channel activation in isolated rat hearts.

PubMed

Dudek, Magdalena; Knutelska, Joanna; Bednarski, Marek; Nowiński, Leszek; Zygmunt, Małgorzata; Bilska-Wilkosz, Anna; Iciek, Małgorzata; Otto, Monika; Żytka, Iwona; Sapa, Jacek; Włodek, Lidia; Filipek, Barbara

2014-06-01

The cardiovascular effects of alpha lipoic acid were evaluated in isolated rat hearts exposed to ischemia-reperfusion injury in vitro. Alpha-lipoic acid raised the level of sulfane sulfur playing an important role in the release of hydrogen sulfide. H2S was shown to prevent the post-reperfusion arrhythmias and to protect the cardiomyocytes from death caused by hypoxia. The activation of potassium ATP-sensitive channels (K(ATP) channels) is one of the most important mechanisms of action of hydrogen sulfide in the cardiovascular system. The aim of this study was to investigate whether alpha lipoic acid can prevent the occurrence of post-reperfusion arrhythmias in vitro using a Langendorff model of ischemia-reperfusion in rats affecting the K(ATP) channels. Alpha lipoic acid significantly improved post-reperfusion cardiac function (reducing incidence of arrhythmias), especially in a dose of 10(-7)M. These cardiovascular effects of this compound on the measured parameters were reversed by glibenclamide, a selective K(ATP) blocker. Alpha lipoic acid increased the level of sulfane sulfur in the hearts. This may suggest that the positive effects caused by alpha lipoic acid in the cardiovascular system are not only related to its strong antioxidant activity, and the influence on the activity of such enzymes as aldehyde dehydrogenase 2, as previously suggested, but this compound can affect K(ATP) channels. It is possible that this indirect effect of alpha lipoic acid is connected with changes in the release of sulfane sulfur and hydrogen sulfide. Copyright © 2014 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Difference in luteal and placental P450(17) alpha: substrate preference and hormonal regulation in the rat.

PubMed

Eckstein, B; Khan, I; Gibori, G

1987-12-01

The purpose of this study was to assess the substrate specificity of P450(17) alpha in both the corpus luteum and placenta of pregnant rats, and to analyse the site at which LH/human chorionic gonadotrophin (hCG) regulates the activities of this enzyme. To distinguish the substrate preference, placentas and corpora lutea were obtained from rats on day 15 of pregnancy. Tissues were homogenized and the 10,000 g supernatants incubated in the presence of equimolar concentrations of [14C]progesterone and [3H]17 alpha-hydroxyprogesterone as substrate with either NADH or NADPH as cofactors for 2, 8, 16 and 24 min. The labelling pattern of both 17 alpha-hydroxyprogesterone and testosterone indicated that the corpus luteum produced testosterone preferentially from progesterone, whereas the placenta principally used 17 alpha-hydroxyprogesterone and synthesized six times as much testosterone from 17 alpha-hydroxyprogesterone than from progesterone. Addition of either NADPH or NADH as cofactors had no effect on substrate preference. The products of the two enzymatic activities were identified by recrystallization to constant 14C/3H ratios. The ratio of 14C/3H in testosterone produced by the corpus luteum was 16-fold higher than in that produced by the placenta. To explore which of the two activities of P450(17) alpha is regulated by the gonadotrophin, rats were treated with either 1.5 IU hCG or vehicle between days 13 and 15 of pregnancy. Hydroxylase and lyase activities were determined on day 15 after incubation for 2, 8, 16 or 24 min in the presence of either NADH or NADPH. Administration of hCG significantly inhibited NADH-dependent 17 alpha-hydroxylase in the placenta at each time-point studied.(ABSTRACT TRUNCATED AT 250 WORDS)

Evidence that N-acetylcysteine inhibits TNF-alpha-induced cerebrovascular endothelin-1 upregulation via inhibition of mitogen- and stress-activated protein kinase.

PubMed

Sury, Matthias D; Frese-Schaper, Manuela; Mühlemann, Miranda K; Schulthess, Fabienne T; Blasig, Ingolf E; Täuber, Martin G; Shaw, Sidney G; Christen, Stephan

2006-11-01

N-acetylcysteine (NAC) is neuroprotective in animal models of acute brain injury such as caused by bacterial meningitis. However, the mechanism(s) by which NAC exerts neuroprotection is unclear. Gene expression of endothelin-1 (ET-1), which contributes to cerebral blood flow decline in acute brain injury, is partially regulated by reactive oxygen species, and thus a potential target of NAC. We therefore examined the effect of NAC on tumor necrosis factor (TNF)-alpha-induced ET-1 production in cerebrovascular endothelial cells. NAC dose dependently inhibited TNF-alpha-induced preproET-1 mRNA upregulation and ET-1 protein secretion, while upregulation of inducible nitric oxide synthase (iNOS) was unaffected. Intriguingly, NAC had no effect on the initial activation (i.e., IkappaB degradation, nuclear p65 translocation, and Ser536 phosphorylation) of NF-kappaB by TNF-alpha. However, transient inhibition of NF-kappaB DNA binding suggested that NAC may inhibit ET-1 upregulation by inhibiting (a) parallel pathway(s) necessary for full transcriptional activation of NF-kappaB-mediated ET-1 gene expression. Similar to NAC, the MEK1/2 inhibitor U0126, the p38 inhibitor SB203580, and the protein kinase inhibitor H-89 selectively inhibited ET-1 upregulation without affecting nuclear p65 translocation, suggesting that NAC inhibits ET-1 upregulation via inhibition of mitogen- and stress-activated protein kinase (MSK). Supporting this notion, cotreatment with NAC inhibited the TNF-alpha-induced rise in MSK1 and MSK2 kinase activity, while siRNA knock-down experiments showed that MSK2 is the predominant isoform involved in TNF-alpha-induced ET-1 upregulation.

Topographical characteristics and principal component structure of the hypnagogic EEG.

PubMed

Tanaka, H; Hayashi, M; Hori, T

1997-07-01

The purpose of the present study was to identify the dominant topographic components of electroencephalographs (EEG) and their behavior during the waking-sleeping transition period. Somnography of nocturnal sleep was recorded on 10 male subjects. Each recording, from "lights-off" to 5 minutes after the appearance of the first sleep spindle, was analyzed. The typical EEG patterns during hypnagogic period were classified into nine EEG stages. Topographic maps demonstrated that the dominant areas of alpha-band activity moved from the posterior areas to anterior areas along the midline of the scalp. In delta-, theta-, and sigma-band activities, the differences of EEG amplitude between the focus areas (the dominant areas) and the surrounding areas increased as a function of EEG stage. To identify the dominant topographic components, a principal component analysis was carried out on a 12-channel EEG data set for each of six frequency bands. The dominant areas of alpha 2- (9.6-11.4 Hz) and alpha 3- (11.6-13.4 Hz) band activities moved from the posterior to anterior areas, respectively. The distribution of alpha 2-band activity on the scalp clearly changed just after EEG stage 3 (alpha intermittent, < 50%). On the other hand, alpha 3-band activity became dominant in anterior areas after the appearance of vertex sharp-wave bursts (EEG stage 7). For the sigma band, the amplitude of extensive areas from the frontal pole to the parietal showed a rapid rise after the onset of stage 7 (the appearance of vertex sharp-wave bursts). Based on the results, sleep onset process probably started before the onset of sleep stage 1 in standard criteria. On the other hand, the basic sleep process may start before the onset of sleep stage 2 or the manually scored spindles.

Alpha-adrenoceptor blockade modifies neurally induced atrial arrhythmias.

PubMed

Richer, Louis-Philippe; Vinet, Alain; Kus, Teresa; Cardinal, René; Ardell, Jeffrey L; Armour, John Andrew

2008-10-01

Our objective was to determine whether neuronally induced atrial arrhythmias can be modified by alpha-adrenergic receptor blockade. In 30 anesthetized dogs, trains of five electrical stimuli (1 mA; 1 ms) were delivered immediately after the P wave of the ECG to mediastinal nerves associated with the superior vena cava. Regional atrial electrical events were monitored with 191 atrial unipolar electrodes. Mediastinal nerve sites were identified that reproducibly initiated atrial arrhythmias. These sites were then restimulated following 1 h (time control, n = 6), or the intravenous administration of naftopidil (alpha(1)-adrenergic blocker: 0.2 mg/kg, n = 6), yohimbine (alpha(2)-adrenergic blocker: 1 mg/kg, n = 6) or both (n = 8). A ganglionic blocker (hexamethonium: 1 mg/kg) was tested in four dogs. Stimulation of mediastinal nerves sites consistently elicited atrial tachyarrhythmias. Repeat stimulation after 1 h in the time-control group exerted a 19% decrease of the sites still able to induce atrial tachyarrhythmias. Hexamethonium inactivated 78% of the previously active sites. Combined alpha-adrenoceptor blockade inactivated 72% of the previously active sites. Bradycardia responses induced by mediastinal nerve stimulation were blunted by hexamethonium, but not by alpha(1,2)-adrenergic blockade. Naftopidil or yohimbine alone eliminated atrial arrhythmia induction from 31% and 34% of the sites (similar to time control). We conclude that heterogeneous activation of the intrinsic cardiac nervous system results in atrial arrhythmias that involve intrinsic cardiac neuronal alpha-adrenoceptors. In contrast to the global suppression exerted by hexamethonium, we conclude that alpha-adrenoceptor blockade targets intrinsic cardiac local circuit neurons involved in arrhythmia formation and not the flow-through efferent projections of the cardiac nervous system.

The X-ray Crystal Structures of Human {alpha}-Phosphomannomutase 1 Reveal the Structural Basis of Congenital Disorder of Glycosylation Type 1a

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

Silvaggi,N.; Zhang, C.; Lu, Z.

2006-01-01

Carbohydrate-deficient glycoprotein syndrome type 1a (CDG-1a) is a congenital disease characterized by severe defects in nervous system development. It is caused by mutations in alpha -phosphomannomutase (of which there are two isozymes, {alpha}-PMM1 and {alpha}-PPM2). Here we report the X-ray crystal structures of human {alpha}-PMM1 in the open conformation, with and without the bound substrate, {alpha}-D-mannose 1-phosphate. {alpha}-PMM1, like most Haloalkanoic Acid Dehalogenase Superfamily (HADSF) members, consists of two domains, the cap and core, which open to bind substrate and then close to provide a solvent exclusive environment for catalysis. The substrate phosphate group is observed at a positively chargedmore » site of the cap domain, rather than at the core domain phosphoryl-transfer site defined by the D19 nucleophile and Mg{sup 2+} cofactor. This suggests that substrate binds first to the cap and then is swept into the active site upon cap closure. The orientation of the acid/base residue D21 suggests that {alpha}-PMM uses a different method of protecting the aspartylphosphate from hydrolysis than the HADSF member {beta}-phosphoglucomutase. It is hypothesized that the electrostatic repulsion of positive charges at the interface of the cap and core domains stabilizes {alpha}-PMM1 in the open conformation, and that the negatively charged substrate binds to the cap, thereby facilitating its closure over the core domain. The two isozymes {alpha}-PMM1 and {alpha}-PMM2 are shown to have a conserved active-site structure and to display similar kinetic properties. Analysis of the known mutation sites in the context of the structures reveals the genotype-phenotype relationship underlying CDG-1a.« less

Ubiquitin conjugation by the N-end rule pathway and mRNAs for its components increase in muscles of diabetic rats.

PubMed

Lecker, S H; Solomon, V; Price, S R; Kwon, Y T; Mitch, W E; Goldberg, A L

1999-11-01

Insulin deficiency (e.g., in acute diabetes or fasting) is associated with enhanced protein breakdown in skeletal muscle leading to muscle wasting. Because recent studies have suggested that this increased proteolysis is due to activation of the ubiquitin-proteasome (Ub-proteasome) pathway, we investigated whether diabetes is associated with an increased rate of Ub conjugation to muscle protein. Muscle extracts from streptozotocin-induced insulin-deficient rats contained greater amounts of Ub-conjugated proteins than extracts from control animals and also 40-50% greater rates of conjugation of (125)I-Ub to endogenous muscle proteins. This enhanced Ub-conjugation occurred mainly through the N-end rule pathway that involves E2(14k) and E3alpha. A specific substrate of this pathway, alpha-lactalbumin, was ubiquitinated faster in the diabetic extracts, and a dominant negative form of E2(14k) inhibited this increase in ubiquitination rates. Both E2(14k) and E3alpha were shown to be rate-limiting for Ub conjugation because adding small amounts of either to extracts stimulated Ub conjugation. Furthermore, mRNA for E2(14k) and E3alpha (but not E1) were elevated 2-fold in muscles from diabetic rats, although no significant increase in E2(14k) and E3alpha content could be detected by immunoblot or activity assays. The simplest interpretation of these results is that small increases in both E2(14k) and E3alpha in muscles of insulin-deficient animals together accelerate Ub conjugation and protein degradation by the N-end rule pathway, the same pathway activated in cancer cachexia, sepsis, and hyperthyroidism.

An experimental study on amelioration of dyslipidemia-induced atherosclesis by Clematichinenoside through regulating Peroxisome proliferator-activated receptor-α mediated apolipoprotein A-I, A-II and C-III.

PubMed

Liu, Chao; Guo, Qianqian; Lu, Mengchen; Li, Yunman

2015-08-15

Prevention or amelioration the prevalence of atherosclerosis has been an effective strategy in the management of cardiovascular diseases. The aim of the study was to scrutinize the effect of Clematichinenoside (AR) on dyslipidemia-induced atherosclerosis and explore its capability on expression of Peroxisome proliferator-activated receptor-α (PPAR-alpha), apolipoprotein A-I (APOA1) and A-II (APOA2), and suppression of apolipoprotein C-III (APOC3) genes and proteins. In the present study, we investigated atherosclerosis effect of AR using a combination of high-fat diet and balloon injury model in rabbits. The levels of biochemical indicators were evaluated in plasma, liver and HepG2 cells using immunoassay technology. In order to expose the underlying mechanism, we evaluated the regulation of PPAR-alpha, APOA1, APOA2 and APOC3 expressions by AR, and we further evaluated the interactions between them after transfection with shRNA (shPPAR-alpha) and, the action of PPAR-alpha in HepG2 cells. We could find that AR markedly promoted the PPAR-alpha transfer from cytoplasm to nucleus which resulted in the alteration of APOA1, APOA2 and APOC3 expressions in HepG2 cells. Moreover, AR significantly reduced total cholesterol, triglycerides and low-density lipoprotein cholesterol (LDL-C) levels, and elevated high-density lipoprotein cholesterol (HDL-C) level, which play an important role in dyslipidemia-induced atherosclerosis. In conclusion, AR ameliorated atherosclerosis via the regulation of hepatic lipid metabolism, and AR also contributed to the activation of PPAR-alpha, APOA1, APOA2 and APOC3. Therefore, AR could be a potential therapeutic agent in the treatment of atherosclerosis. Copyright © 2015 Elsevier B.V. All rights reserved.

Ubiquitin conjugation by the N-end rule pathway and mRNAs for its components increase in muscles of diabetic rats

NASA Technical Reports Server (NTRS)

Lecker, S. H.; Solomon, V.; Price, S. R.; Kwon, Y. T.; Mitch, W. E.; Goldberg, A. L.

1999-01-01

Insulin deficiency (e.g., in acute diabetes or fasting) is associated with enhanced protein breakdown in skeletal muscle leading to muscle wasting. Because recent studies have suggested that this increased proteolysis is due to activation of the ubiquitin-proteasome (Ub-proteasome) pathway, we investigated whether diabetes is associated with an increased rate of Ub conjugation to muscle protein. Muscle extracts from streptozotocin-induced insulin-deficient rats contained greater amounts of Ub-conjugated proteins than extracts from control animals and also 40-50% greater rates of conjugation of (125)I-Ub to endogenous muscle proteins. This enhanced Ub-conjugation occurred mainly through the N-end rule pathway that involves E2(14k) and E3alpha. A specific substrate of this pathway, alpha-lactalbumin, was ubiquitinated faster in the diabetic extracts, and a dominant negative form of E2(14k) inhibited this increase in ubiquitination rates. Both E2(14k) and E3alpha were shown to be rate-limiting for Ub conjugation because adding small amounts of either to extracts stimulated Ub conjugation. Furthermore, mRNA for E2(14k) and E3alpha (but not E1) were elevated 2-fold in muscles from diabetic rats, although no significant increase in E2(14k) and E3alpha content could be detected by immunoblot or activity assays. The simplest interpretation of these results is that small increases in both E2(14k) and E3alpha in muscles of insulin-deficient animals together accelerate Ub conjugation and protein degradation by the N-end rule pathway, the same pathway activated in cancer cachexia, sepsis, and hyperthyroidism.

Augmentation of the noradrenergic system in alpha-2 adrenergic receptor deficient mice: anatomical changes associated with enhanced fear memory.

PubMed

Davies, M Frances; Tsui, Janet Y; Flannery, Judy A; Li, Xiangqi; DeLorey, Timothy M; Hoffman, Brian B

2003-10-03

We have investigated sensitivity to the conditioned fear procedure of mice is influenced by the genetic deletion of alpha2A adrenoceptors (ARs). We observed a heightened freezing response in the discrete cue memory test in alpha2A AR knockout (alpha2A AR KO) mice and in D79N mice, a transgenic mouse strain with functionally impaired alpha2A ARs. No significant differences in contextual memory were observed between control and alpha2A AR KO or D79N mice suggesting a minimal role for the noradrenergic system in contextual memory. We speculated that the increased freezing response of the alpha2A AR KO and D79N mice in the discrete cue setting was due to increased release of norepinephrine evoked by the unconditioned footshock stimulus. In alpha2A AR KO mice we measured a doubling in the number of noradrenergic neurons in the locus coeruleus (LC) and a large increase in the cell volume of tyrosine hydroxylase positive neurons, likely due to selective preservation of large, multipolar neurons in the subcoeruleus. Hyperplasia of the noradrenergic neurons in the nucleus tractus solitarius, A5 and A7, was also observed. Alpha2A AR KO mice exhibit greater c-Fos expression in the LC compared to wild type mice suggesting that the LC neurons in the alpha2A AR KO mice were spontaneously more active. This study suggests that alpha2A ARs are involved in the development of the central noradrenergic system and raises the possibility that alterations in alpha2A AR expression may contribute to variations in fear and stress responses.

Effect of micromolar Ca2+ on NADH inhibition of bovine kidney alpha-ketoglutarate dehydrogenase complex and possible role of Ca2+ in signal amplification.

PubMed

Lawlis, V B; Roche, T E

1980-11-20

NADH inhibition of bovine kidney alpha-ketoglutarate dehydrogenase complex was compared at 10 microM free Ca2+ or in the absence of Ca2+ (i.e., less than 1.0 nM free Ca2+). In the presence of Ca2+, NADH inhibition was appreciably decreased for a wide range of NADH:NAD+ ratios. A half-maximal decrease in NADH inhibition occurred at slightly less than 1 microM free Ca/+ (as determined with EGTA-Ca buffers). Of necessity this was observed on top of an effect of Ca2+ on the S0.5 for alpha-ketoglutarate which was decreased by Ca2+ with a half-maximal effect at a similar concentration. The effect of Ca2+ on NADH inhibition was not observed in assays of the dihydrolipoyl dehydrogenase component (using dihydrolipoamide as a substrate) or in assays of bovine kidney pyruvate dehydrogenase complex. This indicates that the overall reaction catalyzed by the alpha-ketoglutarate dehydrogenase complex is required to elicit the effect of Ca2+ on NADH inhibition. At a fixed alpha-ketoglutarate concentration (50 microM), removal of Ca2+ reduced the activity of the alpha-ketoglutarate dehydrogenase complex by 8.5-fold (due to an increase in S0.5 for alpha-ketoglutarate) and, in the presence of different NADH:NAD+ ratios, decreased the activity of the complex by 50 to 100-fold. Effects of the phosphate potential (ATP/ADPxPi) or a combination of the phosphate potential and NADH:NAD+ ratio are also described. The possibility that the level of intramitochondrial free Ca/+ serves as a signal amplifier normally coupled to the energy state of mitochondria is discussed.

TNF-alpha suppresses the expression of clock genes by interfering with E-box-mediated transcription.

PubMed

Cavadini, Gionata; Petrzilka, Saskia; Kohler, Philipp; Jud, Corinne; Tobler, Irene; Birchler, Thomas; Fontana, Adriano

2007-07-31

Production of TNF-alpha and IL-1 in infectious and autoimmune diseases is associated with fever, fatigue, and sleep disturbances, which are collectively referred to as sickness behavior syndrome. In mice TNF-alpha and IL-1 increase nonrapid eye movement sleep. Because clock genes regulate the circadian rhythm and thereby locomotor activity and may alter sleep architecture we assessed the influence of TNF-alpha on the circadian timing system. TNF-alpha is shown here to suppress the expression of the PAR bZip clock-controlled genes Dbp, Tef, and Hlf and of the period genes Per1, Per2, and Per3 in fibroblasts in vitro and in vivo in the liver of mice infused with the cytokine. The effect of TNF-alpha on clock genes is shared by IL-1beta, but not by IFN-alpha, and IL-6. Furthermore, TNF-alpha interferes with the expression of Dbp in the suprachiasmatic nucleus and causes prolonged rest periods in the dark when mice show spontaneous locomotor activity. Using clock reporter genes TNF-alpha is found here to inhibit CLOCK-BMAL1-induced activation of E-box regulatory elements-dependent clock gene promoters. We suggest that the increase of TNF-alpha and IL-1beta, as seen in infectious and autoimmune diseases, impairs clock gene functions and causes fatigue.

Membrane-derived second messenger regulates x-ray-mediated tumor necrosis factor alpha gene induction.

PubMed Central

Hallahan, D E; Virudachalam, S; Kuchibhotla, J; Kufe, D W; Weichselbaum, R R

1994-01-01

Cells adapt to adverse environmental conditions through a wide range of responses that are conserved throughout evolution. Physical agents such as ionizing radiation are known to initiate a stress response that is triggered by the recognition of DNA damage. We have identified a signaling pathway involving the activation of phospholipase A2 and protein kinase C in human cells that confers x-ray induction of the tumor necrosis factor alpha gene. Treatment of human cells with ionizing radiation or H2O2 was associated with the production of arachidonic acid. Inhibition of phospholipase A2 abolished radiation-mediated arachidonate production as well as the subsequent activation of protein kinase C and tumor necrosis factor alpha gene expression. These findings demonstrate that ionizing radiation-mediated gene expression in human cells is regulated in part by extranuclear signal transduction. One practical application of phospholipase A2 inhibitors is to ameliorate the adverse effects of radiotherapy associated with tumor necrosis factor alpha production. Images PMID:8197153

Variability of antibiotic prescribing in patients with chronic obstructive pulmonary disease exacerbations: a cohort study.

PubMed

Boggon, Rachael; Hubbard, Richard; Smeeth, Liam; Gulliford, Martin; Cassell, Jackie; Eaton, Susan; Pirmohamed, Munir; van Staa, Tjeerd-Pieter

2013-05-31

The role of antibiotics in treating mild or moderate exacerbations in patients with acute chronic obstructive pulmonary disease (COPD) is unclear. The aims were to: (i) describe patient characteristics associated with acute exacerbations amongst a representative COPD population, (ii) explore the relationship between COPD severity and outcomes amongst patients with exacerbations, and (iii) quantify variability by general practice in prescribing of antibiotics for COPD exacerbations. A cohort of 62,747 patients with COPD was identified from primary care general practices (GP) in England, and linked to hospital admission and death certificate data. Exacerbation cases were matched to three controls and characteristics compared using conditional logistic regression. Outcomes were compared using incidence rates and Cox regression, stratified by disease severity. Variability of prescribing at the GP level was evaluated graphically and by using multilevel models. COPD severity was found to be associated with exacerbation and subsequent mortality (very severe vs. mild, odds ratio for exacerbation 2.12 [95%CI 19.5-2.32]), hazard ratio for mortality 2.14 [95%CI 1.59-2.88]). Whilst 61% of exacerbation cases were prescribed antibiotics, this proportion varied considerably between GP practices (interquartile range, 48-73%). This variation is greater than can be explained by patient characteristics alone. There is significant variability between GP practices in the prescribing of antibiotics to COPD patients experiencing exacerbations. Combined with a lack of evidence on the effects of treatment, this supports the need and opportunity for a large scale pragmatic randomised trial of the prescribing of antibiotics for COPD patients with exacerbations, in order to clarify their effectiveness and long term outcomes whilst ensuring the representativeness of subjects.

Variability of antibiotic prescribing in patients with chronic obstructive pulmonary disease exacerbations: a cohort study

PubMed Central

2013-01-01

Background The role of antibiotics in treating mild or moderate exacerbations in patients with acute chronic obstructive pulmonary disease (COPD) is unclear. The aims were to: (i) describe patient characteristics associated with acute exacerbations amongst a representative COPD population, (ii) explore the relationship between COPD severity and outcomes amongst patients with exacerbations, and (iii) quantify variability by general practice in prescribing of antibiotics for COPD exacerbations. Method A cohort of 62,747 patients with COPD was identified from primary care general practices (GP) in England, and linked to hospital admission and death certificate data. Exacerbation cases were matched to three controls and characteristics compared using conditional logistic regression. Outcomes were compared using incidence rates and Cox regression, stratified by disease severity. Variability of prescribing at the GP level was evaluated graphically and by using multilevel models. Results COPD severity was found to be associated with exacerbation and subsequent mortality (very severe vs. mild, odds ratio for exacerbation 2.12 [95%CI 19.5–2.32]), hazard ratio for mortality 2.14 [95%CI 1.59–2.88]). Whilst 61% of exacerbation cases were prescribed antibiotics, this proportion varied considerably between GP practices (interquartile range, 48–73%). This variation is greater than can be explained by patient characteristics alone. Conclusions There is significant variability between GP practices in the prescribing of antibiotics to COPD patients experiencing exacerbations. Combined with a lack of evidence on the effects of treatment, this supports the need and opportunity for a large scale pragmatic randomised trial of the prescribing of antibiotics for COPD patients with exacerbations, in order to clarify their effectiveness and long term outcomes whilst ensuring the representativeness of subjects. PMID:23724907

Models for the action of barley alpha-amylase isozymes on linear substrates.

PubMed

MacGregor, E A; MacGregor, A W; Macri, L J; Morgan, J E

1994-05-05

The formation of maltodextrins, G1 to G12, during the hydrolysis of amylose by alpha-amylases 1 and 2 from barley malt was followed by HPLC. Similar, but not identical, distributions of products were obtained with the two alpha-amylase components. Maltose, G6, and G7 were major products, but G7 was degraded as hydrolysis proceeded. alpha-Amylase 1 produced more G1 and G3 than did alpha-amylase 2 at all stages of hydrolysis. Products formed during the hydrolysis of G9, G10, G11, and G12 by the two alpha-amylases were also determined. A different spectrum of products was observed with each substrate and small differences were observed in the action pattern of the two alpha-amylases, e.g., G3 and G7 were the major products formed during the hydrolysis of G10 by alpha-amylase 1, whereas G2 and G8 were the major products formed by alpha-amylase 2 on the same substrate. These results were used to develop a model of the active site of barley malt alpha-amylases. This site contains ten contiguous subsites with the catalytic site situated between subsites 7 and 8. The model can be used to predict hydrolysis patterns of amylose and maltodextrins by cereal alpha-amylases.

PPAR{alpha} is a potential therapeutic target of drugs to treat circadian rhythm sleep disorders

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

Shirai, Hidenori; Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8502; Oishi, Katsutaka

Recent progress at the molecular level has revealed that nuclear receptors play an important role in the generation of mammalian circadian rhythms. To examine whether peroxisome proliferator-activated receptor alpha (PPAR{alpha}) is involved in the regulation of circadian behavioral rhythms in mammals, we evaluated the locomotor activity of mice administered with the hypolipidemic PPAR{alpha} ligand, bezafibrate. Circadian locomotor activity was phase-advanced about 3 h in mice given bezafibrate under light-dark (LD) conditions. Transfer from LD to constant darkness did not change the onset of activity in these mice, suggesting that bezafibrate advanced the phase of the endogenous clock. Surprisingly, bezafibrate alsomore » advanced the phase in mice with lesions of the suprachiasmatic nucleus (SCN; the central clock in mammals). The circadian expression of clock genes such as period2, BMAL1, and Rev-erb{alpha} was also phase-advanced in various tissues (cortex, liver, and fat) without affecting the SCN. Bezafibrate also phase-advanced the activity phase that is delayed in model mice with delayed sleep phase syndrome (DSPS) due to a Clock gene mutation. Our results indicated that PPAR{alpha} is involved in circadian clock control independently of the SCN and that PPAR{alpha} could be a potent target of drugs to treat circadian rhythm sleep disorders including DSPS.« less

Connection between integrins and cell activation in rat adrenal glomerulosa cells: a role for Arg-Gly-Asp peptide in the activation of the p42/p44(mapk) pathway and intracellular calcium.

PubMed

Campbell, Shirley; Otis, Melissa; Côté, Mylène; Gallo-Payet, Nicole; Payet, Marcel Daniel

2003-04-01

Integrins are responsible for adhesion and activation of several intracellular cascades. The present study was aimed at determining whether the interaction between fibronectin and integrins could generate pathways involved in physiological functions of rat adrenal glomerulosa cells. Immunofluorescence studies and adhesion assays showed that fibronectin was the best matrix in promoting the formation of focal adhesion. Binding of glomerulosa cells to fibronectin, but not to collagen I or poly-L-lysine, involved the integrin-binding sequence Arg-Gly-Asp (RGD). Activation of glomerulosa cells with Arg-Gly-Asp-Ser (RGDS) induced an increase in [Ca(2+)](i), whereas fibronectin triggered a release of Ca(2+) from InsP(3)-sensitive Ca(2+) stores. Aldosterone secretion induced by ACTH, angiotensin II, and RGDS and proliferation were improved on fibronectin, compared with poly-L-lysine. The RGDS peptide induced a transient increase in the activity of the p42/p44(mapk), independent of phosphatidylinositol-3 kinase and protein kinase C. Integrins alpha(5) and alpha(V) as well as their fibronectin receptor partners beta(1) and beta(3), were identified. These results suggest that in rat adrenal glomerulosa cells, binding of the alpha(5)beta(1), alpha(v)beta(1), or alpha(v)beta(3) integrins to fibronectin is involved in the generation of two important signaling events, increase in intracellular calcium, and activation of the p42/p44(mapk) cascade, leading to cell proliferation and aldosterone secretion.

Vitamin C attenuation of the development of type I diabetes mellitus by interferon-alpha.

PubMed

al-Zuhair, H; Mohamed, H E

1998-07-01

Interferon alpha (IFN-alpha) inhibits insulin release and may be cytotoxic to pancreatic islets. Increased free radical activity may be implicated in the cytotoxic action of IFN-alpha and development of diabetes mellitus. Therefore we measured markers of free radical activity (lipid peroxides and the non-peroxide-conjugated diene isomer of linoleic acid [PL-9,11-LA']) along with some pancreatic variables in male albino rats treated with IFN-alpha, as well as the possible protective effect of two antioxidants, vitamin C and mannitol. Compared to untreated rats, it was shown that IFN-alpha induced an increase in plasma glucose. Pancreatic and serum insulin, as well as serum C-peptide, were increased after 1 week, then their levels were reduced after 2 weeks. Plasma lipids peroxides and (PL-9,11-LA') were markedly elevated, while linoleic acid was reduced. These changes in the studied parameters were attributed, in part, to the superoxide and free radical generation during IFN-alpha treatment. Plasma glucagon was increased after 2 weeks. Administration of vitamin C along with IFN-alpha succeeded in modulating most of the altered parameters affected during IFN-alpha. The hyperglycaemic effect of IFN-alpha was greatly ameliorated and the negative effect on pancreatic and serum insulin and serum C-peptide were nearly abolished. The elevated levels of lipid peroxide and (PL-9,11-LA') and the reduction in linoleic acid being normalised. The only persistent effect was the increase in plasma glucagon. Concurrent administration of mannitol with IFN-alpha caused no changes in the parameters studied compared to that induced by treatment with IFN-alpha alone.

De-phosphorylation of TR{alpha}-1 by p44/42 MAPK inhibition enhances T{sub 3}-mediated GLUT5 gene expression in the intestinal cell line Caco-2 cells

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

Mochizuki, Kazuki; Sakaguchi, Naomi; Takabe, Satsuki

2007-08-10

Thyroid hormone and p44/42 MAPK inactivation are important in intestinal differentiation. We demonstrated not only that treatment with p44/42 MAPK inhibitor U0126 in intestinal cell line Caco-2 cells reduced the phosphorylation of serine and threonine residues of TR{alpha}-1, but also that T{sub 3} and U0126 synergistically induced GLUT5 gene expression. EMSA demonstrated that the binding activity of TR{alpha}-1-RXR heterodimer on GLUT5-TRE in nuclear proteins of Caco-2 cells was synergistically enhanced by co-incubation in vitro with T{sub 3} and CIAP, which strongly de-phosphorylates proteins. ChIP and transfection assays revealed that co-treatment of T{sub 3} and U0126 induces TR{alpha}-1-RXR binding to GLUT5-TREmore » on the human GLUT5 enhancer region, and recruitment of the transcriptional complex in cells. These results suggest that inactivation of p44/42 MAPK enhances T{sub 3}-induced GLUT5 gene expression in Caco-2 cells through increasing TR{alpha}-1 transactivity and binding activity to the GLUT5-TRE, probably due to de-phosphorylation of TR{alpha}-1.« less

Activation of protein kinase C by mycobacterial cord factor, trehalose 6-monomycolate, resulting in tumor necrosis factor-alpha release in mouse lung tissues.

PubMed

Sueoka, E; Nishiwaki, S; Okabe, S; Iida, N; Suganuma, M; Yano, I; Aoki, K; Fujiki, H

1995-08-01

Cord factors are mycoloyl glycolipids in cell walls of bacteria belonging to Actinomycetales, such as Mycobacterium, Nocardia and Rhodococcus. They induce granuloma formation in the lung and interstitial pneumonitis, associated with production of macrophage-derived cytokines. We studied how cord factors induce biological activities in the cells. Cord factors isolated from M. tuberculosis, trehalose 6-monomycolate (mTMM) and trehalose 6,6'-dimycolate (mTDM), enhanced protein kinase C (PKC) activation in the presence of phosphatidylserine (PtdSer), diacylglycerol and Ca2+, and mTMM activated PKC alpha more strongly than PKC beta or gamma under the same assay conditions. Kinetic studies of mTMM in response to PKC activation revealed that mTMM increased the apparent affinity of PKC to Ca2+ in the presence of both PtdSer and diolein. Although this is similar to observations with unsaturated fatty acids, such as arachidonic acid, mTMM was synergistic with PtdSer for PKC activation, but arachidonic acid was not. mTMM was also different as regards PKC activation, as phorbol ester was. A single i.p. administration of mTMM to mouse induced tumor necrosis factor-alpha (TNF-alpha) in serum and in the lung, which is a unique target tissue of cord factors. Based on our recent finding that TNF-alpha is an endogenous tumor promoter, the correlation between lung cancer and pulmonary tuberculosis is discussed.

Antibody deficiency in patients with frequent exacerbations of Chronic Obstructive Pulmonary Disease (COPD).

PubMed

McCullagh, Brian N; Comellas, Alejandro P; Ballas, Zuhair K; Newell, John D; Zimmerman, M Bridget; Azar, Antoine E

2017-01-01

Chronic Obstructive Pulmonary Disease is the third leading cause of death in the US, and is associated with periodic exacerbations, which account for the largest proportion of health care utilization, and lead to significant morbidity, mortality, and worsening lung function. A subset of patients with COPD have frequent exacerbations, occurring 2 or more times per year. Despite many interventions to reduce COPD exacerbations, there is a significant lack of knowledge in regards to their mechanisms and predisposing factors. We describe here an important observation that defines antibody deficiency as a potential risk factor for frequent COPD exacerbations. We report a case series of patients who have frequent COPD exacerbations, and who were found to have an underlying primary antibody deficiency syndrome. We also report on the outcome of COPD exacerbations following treatment in a subset with of these patients with antibody deficiency. We identified patients with COPD who had 2 or more moderate to severe exacerbations per year; immune evaluation including serum immunoglobulin levels and pneumococcal IgG titers was performed. Patients diagnosed with an antibody deficiency syndrome were treated with either immunoglobulin replacement therapy or prophylactic antibiotics, and their COPD exacerbations were monitored over time. A total of 42 patients were identified who had 2 or more moderate to severe COPD exacerbations per year. Twenty-nine patients had an underlying antibody deficiency syndrome: common variable immunodeficiency (8), specific antibody deficiency (20), and selective IgA deficiency (1). Twenty-two patients had a follow-up for at least 1 year after treatment of their antibody deficiency, which resulted in a significant reduction of COPD exacerbations, courses of oral corticosteroid use and cumulative annual dose of oral corticosteroid use, rescue antibiotic use, and hospitalizations for COPD exacerbations. This case series identifies antibody deficiency as a potentially treatable risk factor for frequent COPD exacerbations; testing for antibody deficiency should be considered in difficult to manage frequently exacerbating COPD patients. Further prospective studies are warranted to further test this hypothesis.

Antibody deficiency in patients with frequent exacerbations of Chronic Obstructive Pulmonary Disease (COPD)

PubMed Central

McCullagh, Brian N.; Comellas, Alejandro P.; Ballas, Zuhair K.; Newell, John D.; Zimmerman, M. Bridget

2017-01-01

Chronic Obstructive Pulmonary Disease is the third leading cause of death in the US, and is associated with periodic exacerbations, which account for the largest proportion of health care utilization, and lead to significant morbidity, mortality, and worsening lung function. A subset of patients with COPD have frequent exacerbations, occurring 2 or more times per year. Despite many interventions to reduce COPD exacerbations, there is a significant lack of knowledge in regards to their mechanisms and predisposing factors. We describe here an important observation that defines antibody deficiency as a potential risk factor for frequent COPD exacerbations. We report a case series of patients who have frequent COPD exacerbations, and who were found to have an underlying primary antibody deficiency syndrome. We also report on the outcome of COPD exacerbations following treatment in a subset with of these patients with antibody deficiency. We identified patients with COPD who had 2 or more moderate to severe exacerbations per year; immune evaluation including serum immunoglobulin levels and pneumococcal IgG titers was performed. Patients diagnosed with an antibody deficiency syndrome were treated with either immunoglobulin replacement therapy or prophylactic antibiotics, and their COPD exacerbations were monitored over time. A total of 42 patients were identified who had 2 or more moderate to severe COPD exacerbations per year. Twenty-nine patients had an underlying antibody deficiency syndrome: common variable immunodeficiency (8), specific antibody deficiency (20), and selective IgA deficiency (1). Twenty-two patients had a follow-up for at least 1 year after treatment of their antibody deficiency, which resulted in a significant reduction of COPD exacerbations, courses of oral corticosteroid use and cumulative annual dose of oral corticosteroid use, rescue antibiotic use, and hospitalizations for COPD exacerbations. This case series identifies antibody deficiency as a potentially treatable risk factor for frequent COPD exacerbations; testing for antibody deficiency should be considered in difficult to manage frequently exacerbating COPD patients. Further prospective studies are warranted to further test this hypothesis. PMID:28212436

Involvement of activated leukocytes in the regulation of plasma levels of acute phase proteins in microgravity simulation experiments

NASA Astrophysics Data System (ADS)

Larina, Olga; Bekker, Anna; Turin-Kuzmin, Alexey

2016-07-01

Earth-based studies of microgravity effects showed the induction of the mechanisms of acute phase reaction (APR). APR comprises the transition of stress-sensitive protein kinases of macrophages and other responsive cells into the active state and the phosphorylation of transcription factors which in turn stimulate the production of acute-phase reaction cytokines. Leukocyte activation is accompanied by the acceleration of the formation of oxygen radicals which can serve a functional indice of leukocyte cell state. The series of events at acute phase response result in selective changes in the synthesis of a number of secretory blood proteins (acute phase proteins, APPs) in liver cells thus contributing the recovery of homeostasis state in the organism. Earlier experiment with head-down tilt showed the increase in plasma concentrations of two cytokine mediators of acute phase response, tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) being the outcome of the activation of producer cells, foremost, leukocytes. In experiment with 4-day dry immersion chemiluminescent (ChL) reply of the whole blood samples to a test stimulus were studied along with the measurements of plasma levels of APPs, namely, alpha1-antitrypsin (alpha1-AT), alpha1-acid glycoprotein (alpha1-AGP), alpha2-macroglobulin (alpha2-M), ceruloplasmin (Cer), haptoglobin (Hp), C3-complement component (C3), C-reactive protein (CRP). Eight individuals aged 21.2 ± 3.2 years were the test subjects in the investigation. Protein studies showed a noticeable increase in the mean plasma levels of all APPs measured in experiment thus producing the evidence of the activation of acute phase response mechanisms while individual patterns revealed variability during the immersion period. The overall trends were similar to these in the previous immersion series. The augment in the strength of signal in stimulated light emission tests was higher after 1- and 2-day of immersion exposure than before the experiment. The effects obtained in this survey suggest the enhancement of the synthesis of active oxygen species by blood phagocytes at the initial stages of adaptation to immersion conditions. The gain of chemiluminescence signal correlated with maximal augment in APP concentrations registered in the course of 4-day immersion. Moreover, in the only case with zero effects in chemiluminescent reply stable APP levels were obtained. The data from functional studies performed with phagocytic cells in the experiment with dry immersion corroborate their implication in acute phase mechanisms participating in the adaptation to simulated microgravity conditions.

Binding of [alpha, alpha]-Disubstituted Amino Acids to Arginase Suggests New Avenues for Inhibitor Design

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

Ilies, Monica; Di Costanzo, Luigi; Dowling, Daniel P.

Arginase is a binuclear manganese metalloenzyme that hydrolyzes L-arginine to form L-ornithine and urea, and aberrant arginase activity is implicated in various diseases such as erectile dysfunction, asthma, atherosclerosis, and cerebral malaria. Accordingly, arginase inhibitors may be therapeutically useful. Continuing our efforts to expand the chemical space of arginase inhibitor design and inspired by the binding of 2-(difluoromethyl)-L-ornithine to human arginase I, we now report the first study of the binding of {alpha},{alpha}-disubstituted amino acids to arginase. Specifically, we report the design, synthesis, and assay of racemic 2-amino-6-borono-2-methylhexanoic acid and racemic 2-amino-6-borono-2-(difluoromethyl)hexanoic acid. X-ray crystal structures of human arginase Imore » and Plasmodium falciparum arginase complexed with these inhibitors reveal the exclusive binding of the L-stereoisomer; the additional {alpha}-substituent of each inhibitor is readily accommodated and makes new intermolecular interactions in the outer active site of each enzyme. Therefore, this work highlights a new region of the protein surface that can be targeted for additional affinity interactions, as well as the first comparative structural insights on inhibitor discrimination between a human and a parasitic arginase.« less

Influence of major structural features of tocopherols and tocotrienols on their omega-oxidation by tocopherol-omega-hydroxylase.

PubMed

Sontag, Timothy J; Parker, Robert S

2007-05-01

Human cytochrome P450 4F2 (CYP4F2) catalyzes the initial omega-hydroxylation reaction in the metabolism of tocopherols and tocotrienols to carboxychromanols and is, to date, the only enzyme shown to metabolize vitamin E. The objective of this study was to characterize this activity, particularly the influence of key features of tocochromanol substrate structure. The influence of the number and positions of methyl groups on the chromanol ring, and of stereochemistry and saturation of the side chain, were explored using HepG2 cultures and microsomal reaction systems. Human liver microsomes and microsomes selectively expressing recombinant human CYP4F2 exhibited substrate activity patterns similar to those of HepG2 cells. Although activity was strongly associated with substrate accumulation by cells or microsomes, substantial differences in specific activities between substrates remained under conditions of similar microsomal membrane substrate concentration. Methylation at C5 of the chromanol ring was associated with markedly low activity. Tocotrienols exhibited much higher Vmax values than their tocopherol counterparts. Side chain stereochemistry had no effect on omega-hydroxylation of alpha-tocopherol (alpha-TOH) by any system. Kinetic analysis of microsomal CYP4F2 activity revealed Michaelis-Menten kinetics for alpha-TOH but allosteric cooperativity for other vitamers, especially tocotrienols. Additionally, alpha-TOH was a positive effector of omega-hydroxylation of other vitamers. These results indicate that CYP4F2-mediated tocopherol-omega-hydroxylation is a central feature underlying the different biological half-lives, and therefore biopotencies, of the tocopherols and tocotrienols.

In vitro anti-inflammatory effects of arctigenin, a lignan from Arctium lappa L., through inhibition on iNOS pathway.

PubMed

Zhao, Feng; Wang, Lu; Liu, Ke

2009-04-21

Arctigenin, a bioactive constituent from dried seeds of Arctium lappa L. (Compositae) which has been widely used as a Traditional Chinese Medicine for dispelling wind and heat included in Chinese Pharmacophere, was found to exhibit anti-inflammatory activities but its molecular mechanism remains unknown yet. To investigate the anti-inflammatory mechanism of arctigenin. Cultured macrophage RAW 264.7 cells and THP-1 cells were used for the experiments. Griess assay was used to evaluate the inhibitory effect of arctigenin on the overproduction of nitric oxide (NO). ELISA was used to determine the level of pro-inflammatory cytokines including tumor necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6). The inhibitory effect on the enzymatic activity of cyclooxygenase-2 (COX-2) was tested by colorimetric method. Western blot was used to detect the expression of inducible nitric oxide synthase (iNOS) and COX-2. Arctigenin suppressed lipopolysaccharide (LPS)-stimulated NO production and pro-inflammatory cytokines secretion, including TNF-alpha and IL-6 in a dose-dependent manner. Arctigenin also strongly inhibited the expression of iNOS and iNOS enzymatic activity, whereas the expression of COX-2 and COX-2 enzymatic activity were not affected by arctigenin. These results indicated that potent inhibition on NO, TNF-alpha and IL-6, but not COX-2 expression and COX-2 activity, might constitute the anti-inflammatory mechanism of arctigenin. Arctigenin suppressed the overproduction of NO through down-regulation of iNOS expression and iNOS enzymatic activity in LPS-stimulated macrophage.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) increases necroinflammation and hepatic stellate cell activation but does not exacerbate experimental liver fibrosis in mice

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

Lamb, Cheri L.; Cholico, Giovan N.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a persistent environmental contaminant and high-affinity ligand for the aryl hydrocarbon receptor (AhR). Increasing evidence indicates that AhR signaling contributes to wound healing, which involves the coordinated deposition and remodeling of the extracellular matrix. In the liver, wound healing is attributed to the activation of hepatic stellate cells (HSCs), which mediate fibrogenesis through the production of soluble mediators and collagen type I. We recently reported that TCDD treatment increases the activation of human HSCs in vitro. The goal of this study was to determine how TCDD impacts HSC activation in vivo using a mouse model of experimentalmore » liver fibrosis. To elicit fibrosis, C57BL6/male mice were treated twice weekly for 8 weeks with 0.5 ml/kg carbon tetrachloride (CCl{sub 4}). TCDD (20 μg/kg) or peanut oil (vehicle) was administered once a week during the last 2 weeks. Results indicate that TCDD increased liver-body-weight ratios, serum alanine aminotransferase activity, and hepatic necroinflammation in CCl{sub 4}-treated mice. Likewise, TCDD treatment increased mRNA expression of HSC activation and fibrogenesis genes, namely α-smooth muscle actin, desmin, delta-like homolog-1, TGF-β1, and collagen type I. However, TCDD treatment did not exacerbate fibrosis, nor did it increase the collagen content of the liver. Instead, TCDD increased hepatic collagenase activity and increased expression of matrix metalloproteinase (MMP)-13 and the matrix regulatory proteins, TIMP-1 and PAI-1. These results support the conclusion that TCDD increases CCl{sub 4}-induced liver damage and exacerbates HSC activation, yet collagen deposition and the development of fibrosis may be limited by TCDD-mediated changes in extracellular matrix remodeling. - Highlights: • TCDD increased liver damage and inflammation in mice treated with CCl{sub 4}. • TCDD treatment enhanced markers of hepatic stellate cell activation and fibrogenesis. • TCDD did not increase the deposition of collagen type I or the severity of liver fibrosis. • TCDD increased hepatic collagenase activity and expression of matrix metalloproteinase-13.« less

Anti-inflammatory activity of methylene chloride fraction from Glehnia littoralis extract via suppression of NF-kappa B and mitogen-activated protein kinase activity.

PubMed

Yoon, Taesook; Cheon, Myeong Sook; Lee, A Yeong; Lee, Do Yeon; Moon, Byeong Cheol; Chun, Jin Mi; Choo, Byung Kil; Kim, Ho Kyoung

2010-01-01

Glehnia littoralis (Umbelliferae) has been used traditionally in Korean, Japanese, and Chinese medicine for the treatment of immune-related diseases; however, its anti-inflammatory activity and underlying mechanism remain to be defined. We investigated the anti-inflammatory effect and inhibitory mechanism on inflammation by the methylene chloride fraction from Glehnia littoralis extract (MCF-GLE), which was more effective than Glehnia littoralis extract (GLE). MCF-GLE inhibited 12-O-Tetradecanoyl-phorbol-13-acetate (TPA)-induced inflammation in an inflammatory edema mouse model. Also, MCF-GLE strongly inhibited the releases of nitric oxide (NO), prostaglandin E(2) (PGE(2)), tumor necrosis factor-alpha (TNF-alpha), and interleukin-1beta (IL-1beta) and significantly suppressed the mRNA and protein expression of inducible nitric oxide synthase and cyclooxygenase-2 in lipopolysaccharide-stimulated RAW 264.7 macrophage cells in a dose-dependent manner. Furthermore, MCF-GLE suppressed NF-kappaB activation and IkappaB-alpha degradation. MCF-GLE also attenuated the activation of ERK and JNK in a dose-dependent manner. These results indicate that MCF-GLE has an inhibitory effect on the in vivo and in vitro inflammatory reaction and is a possible therapeutic agent. Our results suggest that the anti-inflammatory properties of MCF-GLE may result from the inhibition of pro-inflammatory mediators, such as NO, PGE(2), TNF-alpha, and IL-1beta via suppression of NF-kappaB- and mitogen-activated protein kinases-dependent pathways.

Association of protein kinase FA/GSK-3alpha (a proline-directed kinase and a regulator of protooncogenes) with human cervical carcinoma dedifferentiation/progression.

PubMed

Yang, S D; Yu, J S; Lee, T T; Ni, M H; Yang, C C; Ho, Y S; Tsen, T Z

1995-10-01

Computer analysis of protein phosphorylation-sites sequence revealed that most transcriptional factors and viral oncoproteins are prime targets for regulation of proline-directed protein phosphorylation, suggesting an association of proline-directed protein kinase (PDPK) family with neoplastic transformation and tumorigenesis. In this report, an immunoprecipitate activity assay of protein kinase FA/glycogen synthase kinase-3alpha (kinase FA/GSK-3alpha) (a particular member of PDPK family) has been optimized for human cervical tissue and used to demonstrate for the first time significantly increased (P < 0.001) activity in poorly differentiated cervical carcinoma (82.8 +/- 6.6 U/mg of protein), moderately differentiated carcinoma (36.2 +/- 3.4 U/mg of protein), and well-differentiated carcinoma (18.3 +/- 2.4 U/mg of protein) from 36 human cervical carcinoma samples when compared to 12 normal controls (4.9 +/- 0.6 U/mg of protein). Immunoblotting analysis further revealed that increased activity of kinase FA/GSK-3alpha in cervical carcinoma is due to overexpression of protein synthesis of the kinase. Taken together, the results provide initial evidence that overexpression of protein synthesis and cellular activity of kinase FA/GSK-3alpha may be involved in human cervical carcinoma dedifferentiation/progression, supporting an association of proline-directed protein kinase with neoplastic transformation and tumorigenesis. Since protein kinase FA/GSK-3alpha may function as a possible regulator of transcription factors/proto-oncogenes, the results further suggest that kinase FA/GSK-3alpha may play a potential role in human cervical carcinogenesis, especially in its dedifferentiation and progression.

Evolution and Activity in the Solar Corona: A Comparison of Coronal and Chromospheric Structures Seen in Soft X-Rays, White Light and H-Alpha Emission

NASA Technical Reports Server (NTRS)

Bagenal, Fran

2001-01-01

The work completed under this project, 'Evolution and Activity in the Solar Corona: A Comparison of Coronal and Chromospheric Structures Seen in Soft X-Rays, White Light and H-Alpha Emission', includes the following presentations: (1) Analysis of H-alpha Observations of High-altitude Coronal Condensations; (2) Multi-spectral Imaging of Coronal Activity; (3) Measurement and Modeling of Soft X-ray Loop Arcades; (4) A Study of the Origin and Dynamics of CMEs; and various poster presentations and thesis dissertations.

Neural control of renal function: role of renal alpha adrenoceptors.

PubMed

DiBona, G F

1985-01-01

Adrenoceptors of various subtypes mediate the renal functional responses to alterations in efferent renal sympathetic nerve activity, the neural component, and renal arterial plasma catecholamine concentrations, the humoral component, of the sympathoadrenergic nervous system. Under normal physiologic as well as hypertensive conditions, the influence of the renal sympathetic nerves predominates over that of circulating plasma catecholamines. In most mammalian species, increases in efferent renal sympathetic nerve activity elicit renal vasoconstrictor responses mediated predominantly by renal vascular alpha-1 adrenoceptors, increases in renin release mediated largely by renal juxtaglomerular granular cell beta-1 adrenoceptors with involvement of renal vascular alpha-1 adrenoceptors only when renal vasoconstriction occurs, and direct increases in renal tubular sodium and water reabsorption mediated predominantly by renal tubular alpha-1 adrenoceptors. In most mammalian species, alpha-2 adrenoceptors do not play a significant role in the renal vascular or renin release responses to renal sympathoadrenergic stimulation. Although renal tubular alpha-2 adrenoceptors do not mediate the increases in renal tubular sodium and water reabsorption produced by increases in efferent renal sympathetic nerve activity, they may be involved through their inhibitory effect on adenylate cyclase in modulating the response to other hormonal agents that influence renal tubular sodium and water reabsorption via stimulation of adenylate cyclase.

Increased choline kinase activity in 1,2-dimethylhydrazine-induced rat colon cancer.

PubMed

Nakagami, K; Uchida, T; Ohwada, S; Koibuchi, Y; Morishita, Y

1999-11-01

Cancer cells acquire particular characteristics that benefit their proliferation. We previously reported that human colon cancers examined had increased choline kinase activity and phosphocholine levels. The elevated phosphocholine levels were in part due to both activation of choline kinase and increased choline kinase alpha protein levels. In this report, we analyzed choline kinase, which catalyzes the phosphorylation of choline to produce phosphocholine, in rat 1,2-dimethylhydrazine (DMH)-induced colon cancer. This study is the first to demonstrate increased choline kinase alpha enzymatic activity, protein levels, and mRNA levels in DMH-induced colon cancer as well as human colon cancer, although phosphocholine was not increased in DMH-induced rat cancer. The increase in the mRNA level was partly due to an increase in the transcription of the choline kinase alpha gene. The increased choline kinase activity may be a specific characteristic acquired by cancer cells that benefits their proliferation.

Targeting deficiencies in mitochondrial respiratory complex I and functional uncoupling exerts anti-seizure effects in a genetic model of temporal lobe epilepsy and in a model of acute temporal lobe seizures.

PubMed

Simeone, Kristina A; Matthews, Stephanie A; Samson, Kaeli K; Simeone, Timothy A

2014-01-01

Mitochondria actively participate in neurotransmission by providing energy (ATP) and maintaining normative concentrations of reactive oxygen species (ROS) in both presynaptic and postsynaptic elements. In human and animal epilepsies, ATP-producing respiratory rates driven by mitochondrial respiratory complex (MRC) I are reduced, antioxidant systems are attenuated and oxidative damage is increased. We report that MRCI-driven respiration and functional uncoupling (an inducible antioxidant mechanism) are reduced and levels of H2O2 are elevated in mitochondria isolated from KO mice. Experimental impairment of MRCI in WT hippocampal slices via rotenone reduces paired-pulse ratios (PPRs) at mossy fiber-CA3 synapses (resembling KO PPRs), and exacerbates seizure-like events in vitro. Daily treatment with AATP [a combination therapy composed of ascorbic acid (AA), alpha-tocopherol (T), sodium pyruvate (P) designed to synergistically target mitochondrial impairments] improved mitochondrial functions, mossy fiber PPRs, and reduced seizure burden index (SBI) scores and seizure incidence in KO mice. AATP pretreatment reduced severity of KA-induced seizures resulting in 100% protection from the severe tonic-clonic seizures in WT mice. These data suggest that restoration of bioenergetic homeostasis in the brain may represent a viable anti-seizure target for temporal lobe epilepsy. Copyright © 2013 Elsevier Inc. All rights reserved.

Identification of protective components that prevent the exacerbation of goose fatty liver: Characterization, expression and regulation of adiponectin receptors.

PubMed

Geng, Tuoyu; Yang, Biao; Li, Fuyuan; Xia, Lili; Wang, Qianqian; Zhao, Xing; Gong, Daoqing

2016-01-01

Fat accumulation in the liver is a natural process in goose, which prepares goose for long-distance migration. In contrast to mammalian fatty liver that usually progresses into an irreversible status, steatohepatitis, goose fatty liver can return to normal without obvious pathological damage, suggesting a protective system exists in goose liver. This study was to identify the components of this system. We first focused on goose adiponectin receptor 1 and 2 (Adipor1/2) as they have ceramidase activity, and can cleave ceramide, a group of proinflammatory signaling lipid species. Quantitative analysis indicated that tumor necrosis factor alpha (Tnfα), a key proinflammatory cytokine, was down-regulated in goose fatty liver by overfeeding. This inhibition of Tnfα was accompanied with reduced adiponectin and increased Adipor1/2 in the adipose tissues and in the livers of the overfed geese, respectively. To investigate the regulation of goose Adipor2 in the context of fatty liver, we treated goose primary hepatocytes with fatty liver associated factors. Data indicated that Adipor2 was upregulated by glucose and oleate but not palmitate. Its expression was even suppressed by high level of insulin. The regulation of Adipor1 by these factors was quite similar to that of Adipor2 except that glucose did not induce Adipor1. Together, these findings suggest the upregulation of Adipor1/2 may, at least partially, contribute to the inhibition of inflammation in goose fatty liver, and the expression of Adipor1/2 can be regulated by fatty liver-associated factors. Copyright © 2016 Elsevier Inc. All rights reserved.

Purification and characterization of an alpha-amylase of Pichia burtonii isolated from the traditional starter "murcha" in Nepal.

PubMed

Takeuchi, Akiko; Shimizu-Ibuka, Akiko; Nishiyama, Yoshitaka; Mura, Kiyoshi; Okada, Sanae; Tokue, Chiyoko; Arai, Soichi

2006-12-01

Among more than 20 yeast strains isolated from the traditional starter "murcha" in Nepal, we characterized a yeast that might be involved in saccharification. This strain, identified as Pichia burtonii, produced an extracellular amylolytic enzyme when cultured in the presence of starch in the medium. Since no amylase secreted by P. burtonii has yet been reported, we purified the enzyme and determined its N-terminal amino acid sequence. Together with the results of a hydrolyzing activity assay toward various substrates, it was found to be an alpha-amylase. The purified enzyme, named Pichia burtonii alpha-amylase (PBA), was a glycoprotein with an apparent molecular mass of 51 kDa. Enzyme activity was optimal at pH 5.0 at 40 degrees C. The enzyme retained 80% of its original activity after incubation under the optimal pH condition at 50 degrees C for 30 min. The activity was inhibited by metal ions such as Cd(2+), Cu(2+), Hg(2+), Al(3+), and Zn(2+).

Preparation and catalytic activities of LaFeO3 and Fe2O3 for HMX thermal decomposition.

PubMed

Wei, Zhi-Xian; Xu, Yan-Qing; Liu, Hai-Yan; Hu, Chang-Wen

2009-06-15

Perovskite-type LaFeO(3) and alpha-Fe(2)O(3) with high specific surface areas were directly prepared with appropriate stearic acid-nitrates ratios by a novel stearic acid solution combustion method. The obtained powders were characterized by XRD, FT-IR and XPS techniques. The catalytic activities of perovskite-type LaFeO(3) and alpha-Fe(2)O(3) for the thermal decomposition of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) were investigated by TG and TG-EGA techniques. The experimental results show that the catalytic activity of perovskite-type LaFeO(3) was much higher than that of alpha-Fe(2)O(3) because of higher concentration of surface-adsorbed oxygen (O(ad)) and hydroxyl of LaFeO(3). The study points out a potential way to develop new and more active perovskite-type catalysts for the HMX thermal decomposition.

Expression of biologically active human interferon alpha 2 in aloe vera

USDA-ARS?s Scientific Manuscript database

We have developed a system for transgenic expression of proteins in Aloe Vera. Using this approach we have generated plants expressing the human gene interferon alpha 2, IFNa2. IFNa2 is a small secreted cytokine that plays a vital role in regulating the body’s immune response to viral infections a...

Sports Dermatology: Part 1 of 2 Traumatic or Mechanical Injuries, Inflammatory Conditions, and Exacerbations of Pre-existing Conditions

PubMed Central

Sivek, Rachel; Marciniak, Brian

2015-01-01

Competitive athletes endure extreme bodily stress when participating in sports-related activities. An athlete’s skin is particularly susceptible to a wide array of repetitive physical and environmental stressors that challenge the skin’s protective function. Many unique dermatoses are well-known to the serious athlete due to countless hours of intense physical training, but are frequently unrecognized by many healthcare professionals. Sports dermatology is a distinctive, budding field of dermatology that focuses on dermatoses frequently encountered in athletes. Athletic skin problems are notoriously infectious in nature due to the inherent environment of close-contact physical activity. Nonetheless, other skin conditions can manifest or worsen with recurring mechanical or traumatic injury or exposure to environmental hazards. Additionally, sports-related activities may exacerbate other pre-existing dermatological conditions that may possibly be unknown to the athlete or clinician. The objective of this two-part review is to arm the astute physician with the fundamental knowledge of the range of dermatological conditions distinct to the competitive athlete. Knowledge of these cutaneous conditions in the context of specific sporting events will permit the clinician to manage these unique patients most effectively. Part one will focus on traumatic or mechanical injuries, inflammatory conditions, and exacerbations of pre-existing conditions frequently seen in athletes. PMID:26060516

[Role of central alpha-adrenoreceptors in the mechanism of the hyperthermic action of prostaglandin E2].

PubMed

Gurin, V N; Vismont, F I; Tsariuk, V V

1984-01-01

It has been demonstrated in rat experiments that the central action of PGE2 results in body temperature rise associated with a reduction in the functional activity of hypothalamic adrenergic systems. In contrast to PGE2 and the beta-adrenomimetic isoproterenol, the alpha-adrenomimetics noradrenaline, mezaton and clonidine were shown to lower body temperature. In the rabbit, clonidine and PGE2 were found to have opposing effects on the neuronal activity of the anterior hypothalamus.

Mechanisms of intracellular calcium homeostasis in developing and mature bovine corpora lutea.

PubMed

Wright, Marietta F; Bowdridge, Elizabeth; McDermott, Erica L; Richardson, Samuel; Scheidler, James; Syed, Qaisar; Bush, Taylor; Inskeep, E Keith; Flores, Jorge A

2014-03-01

Although calcium (Ca(2+)) is accepted as an intracellular mediator of prostaglandin F2 alpha (PGF2alpha) actions on luteal cells, studies defining mechanisms of Ca(2+) homeostasis in bovine corpora lutea (CL) are lacking. The increase in intracellular Ca(2+) concentration ([Ca(2+)]i) induced by PGF2alpha in steroidogenic cells from mature CL is greater than in those isolated from developing CL. Our hypothesis is that differences in signal transduction associated with developing and mature CL contribute to the increased efficacy of PGF2alpha to induce a Ca(2+) signal capable of inducing regression in mature CL. To test this hypothesis, major genes participating in Ca(2+) homeostasis in the bovine CL were identified, and expression of mRNA, protein, or activity, in the case of phospholipase Cbeta (PLCbeta), in developing and mature bovine CL was compared. In addition, we examined the contribution of external and internal Ca(2+) to the PGF2alpha stimulated rise in [Ca(2+)]i in LLCs isolated from developing and mature bovine CL. Three differences were identified in mechanisms of calcium homeostasis between developing and mature CL, which could account for the lesser increase in [Ca(2+)]i in response to PGF2alpha in developing than in mature CL. First, there were lower concentrations of inositol 1,4,5-trisphosphate (IP3) after similar PGF2alpha challenge, indicating reduced phospholipase C beta (PLCbeta) activity, in developing than mature CL. Second, there was an increased expression of sorcin (SRI) in developing than in mature CL. This cytoplasmic Ca(2+) binding protein modulates the endoplasmic reticulum (ER) Ca(2+) release channel, ryanodine receptor (RyR), to be in the closed configuration. Third, there was greater expression of ATP2A2 or SERCA, which causes calcium reuptake into the ER, in developing than in mature CL. Developmental differences in expression detected in whole CL were confirmed by Western blots using protein samples from steroidogenic cells isolated from developing and mature CL. Localization of these genes in steroidogenic luteal cells was confirmed by immunohistochemistry. Therefore, it is concluded that the cellular mechanisms that allow PGF2alpha to induce a calcium signal of greater magnitude in mature than in developing CL involve 1) greater PLCbeta activity with enhanced generation of IP3, 2) an enhanced Ca(2+) release from the ER via unrestrained RYR2 due to a decrease in SRI expression, and 3) a reduction in calcium reuptake to the ER due to lower expression of ATP2A2. Accordingly, the increase in [Ca(2+)]i induced by PGF2alpha in mature large steroidogenic cells had less dependency from extracellular calcium than in those isolated from immature CL.

Flavonoid characterization and in vitro antioxidant activity of Aconitum anthora L. (Ranunculaceae).

PubMed

Mariani, Cristina; Braca, Alessandra; Vitalini, Sara; De Tommasi, Nunziatina; Visioli, Francesco; Fico, Gelsomina

2008-03-01

In this paper, we report studies on morphological, phytochemical, and biological aspects of a population belonging to Aconitum anthora L. Two compounds, quercetin 3-O-((beta-D-glucopyranosyl-(1-->3)-(4-O-(E-p-coumaroyl))-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-galactopyranoside))-7-O-alpha-L-rhamnopyranoside (1) and kaempferol 3-O-((beta-D-glucopyranosyl-(1-->3)-(4-O-(E-p-coumaroyl))-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-galactopyranoside))-7-O-alpha-L-rhamnopyranoside (2), together with two known flavonol glycosides (3-4) were isolated and identified from A. anthora. The antioxidant activity of the four identified flavonoids was screened by three in vitro tests.

The Jak-STAT pathway stimulated by interferon alpha or interferon beta.

PubMed

Horvath, Curt M

2004-11-23

Type I interferons, such as interferon alpha and interferon beta (IFN-alpha and beta), signal through a Janus kinase (Jak) to signal transduction and activator of transcription (STAT) pathway to stimulate gene expression. In response to ligand binding, the receptors dimerize, Jaks phosphorylate STAT1 and STAT2, which then dimerize and interact with a third transcriptional regulator IFN regulatory factor 9 (IRF9) to stimulate gene expression. IFN-alpha is the main innate antiviral cytokine and is essential for effective immune response to viral infection. The animation shows activation of STAT-responsive gene expression in response to type I IFNs.

Essential role of protein kinase C delta in platelet signaling, alpha IIb beta 3 activation, and thromboxane A2 release.

PubMed

Yacoub, Daniel; Théorêt, Jean-François; Villeneuve, Louis; Abou-Saleh, Haissam; Mourad, Walid; Allen, Bruce G; Merhi, Yahye

2006-10-06

The protein kinase C (PKC) family is an essential signaling mediator in platelet activation and aggregation. However, the relative importance of the major platelet PKC isoforms and their downstream effectors in platelet signaling and function remain unclear. Using isolated human platelets, we report that PKCdelta, but not PKCalpha or PKCbeta, is required for collagen-induced phospholipase C-dependent signaling, activation of alpha(IIb)beta(3), and platelet aggregation. Analysis of PKCdelta phosphorylation and translocation to the membrane following activation by both collagen and thrombin indicates that it is positively regulated by alpha(IIb)beta(3) outside-in signaling. Moreover, PKCdelta triggers activation of the mitogen-activated protein kinase-kinase (MEK)/extracellular-signal regulated kinase (ERK) and the p38 MAPK signaling. This leads to the subsequent release of thromboxane A(2), which is essential for collagen-induced but not thrombin-induced platelet activation and aggregation. This study adds new insight to the role of PKCs in platelet function, where PKCdelta signaling, via the MEK/ERK and p38 MAPK pathways, is required for the secretion of thromboxane A(2).

Syntheses and biological activities of 13-substituted avermectin aglycons.

PubMed

Mrozik, H; Linn, B O; Eskola, P; Lusi, A; Matzuk, A; Preiser, F A; Ostlind, D A; Schaeffer, J M; Fisher, M H

1989-02-01

The reactions of sulfonate esters of the allylic/homoallylic 13-alcohol of 5-O-(tert-butyldimethylsilyl)-22,23-dihydroavermectin B1a aglycon (1a) were investigated. Nucleophilic substitution gave 13 beta-chloro and 13 beta-iodo derivatives, while solvolytic reaction conditions yielded 13 alpha-methoxy, 13 alpha-fluoro, and 13 alpha-chloro products. A mixture of 13 alpha- and 13 beta-fluorides was obtained upon reaction with DAST. The 13 beta-iodide gave, upon elimination with lutidine, the 8(9),10(11),12(13),14(15)-tetraene. The 13 beta-alcohol and the rearranged 15-ol 13(14)-ene and 15-amino 13(14)-ene derivatives were obtained by substitution via the allylic carbonium ion. MEM ethers 11 and 12 of the two epimeric 13-ols were prepared by alkylation with MEM chloride. In contrast, methylation of 1a with MeI and Ag2O in CH2Cl2 occurred exclusively at the tertiary 7-hydroxy group and not at the secondary 13 alpha-ol. Oxidation of the allylic alcohol 1a proceeded under Swern conditions but not with MnO2 to the 13-oxo aglycon, which was reduced by NaBH4 exclusively to the natural 13 alpha-ol, while reductive amination with NaCNBH3-NH4OAc gave the 13 alpha-amine. The methoxime derivative was obtained in the form of the two geometric isomers. Anthelmintic activities against the sheep nematode Trichostrongylus colubriformis, miticidal activities against the two-spotted spider mite (Tetranychus urticae), and insecticidal activities against the southern armyworm (Spodoptera eridania) as well as the binding constants to a free living nematode (Caenorhabditis elegans) derived receptor assay were obtained and compared to avermectin B1a, 22,23-dihydroavermectin B1a, and the 13-deoxy-22,23-dihydroavermectin B1 aglycon related to the milbemycins. None of the newly prepared derivatives exceeded the potency of the three reference compounds. Lipophilic 13-substituents such as halogen, alkoxy, and methoxime retained high biological activities in all assays, while the more polar substituents hydroxy and amino had weaker activities. Rearranged 15-substituted 13(14)-ene derivatives were completely inactive. The 13-oxo and the 12,13-dehydro analogues were only weakly active in vivo despite having good binding affinity to the receptor, possibly due to instability or poor absorption.

The Role of Airborne Proteins in Atopic Dermatitis

PubMed Central

Hostetler, Sarah Grim; Kaffenberger, Benjamin; Hostetler, Todd

2010-01-01

Atopic dermatitis is a common, chronic skin condition. A subpopulation of patients may have cutaneous exposure to common airborne proteins exacerbating their disease through direct proteolytic activity, direct activation of proteinase-activated receptor-2 itch receptors, and immunoglobulin E binding. The most common airborne proteins significant in atopic dermatitis include house dust mites, cockroach, pet dander, and multiple pollens. The literature on atopy patch testing, skin-prick testing, and specific IgE is mixed, with greater support for the use of atopy patch test. Patients with airborne proteins contributing to their disease typically have lesions predominately on air-exposed skin surfaces including the face, neck, and arms; a history of exacerbations after exposure to airborne proteins; severe disease resistant to conventional therapies; and concurrent asthma. Treatment strategies include airborne protein avoidance, removal of airborne proteins from the skin, and barrier repair. Further research is needed to establish the benefit of allergen-specific immunotherapy. PMID:20725535

KIR2DL4 differentially signals downstream functions in human NK cells through distinct structural modules.

PubMed

Miah, S M Shahjahan; Hughes, Tracey L; Campbell, Kerry S

2008-03-01

KIR2DL4 (2DL4) is a member of the killer cell Ig-like receptor (KIR) family in human NK cells. It can stimulate potent cytokine production and weak cytolytic activity in resting NK cells, but the mechanism for 2DL4-mediated signaling remains unclear. In this study we characterized the signaling pathways stimulated by 2DL4 engagement. In a human NK-like cell line, KHYG-1, cross-linking of 2DL4 activated MAPKs including JNK, ERK, and p38. Furthermore, 2DL4 cross-linking resulted in phosphorylation of IkappaB kinase beta (IKKbeta) and the phosphorylation and degradation of IkappaBalpha, which indicate activation of the classical NF-kappaB pathway. Engagement of 2DL4 was also shown to activate the transcription and translation of a variety of cytokine genes, including TNF-alpha, IFN-gamma, MIP1alpha, MIP1beta, and IL-8. Pharmacological inhibitors of JNK, MEK1/2 and p38, blocked IFN-gamma, IL-8, and MIP1alpha production, suggesting that MAPKs are regulating 2DL4-mediated cytokine production in a nonredundant manner. Activation of both p38 and ERK appear to be upstream of the stimulation of NF-kappaB. Mutation of a transmembrane arginine in 2DL4 to glycine (R/G mutant) abrogated FcepsilonRI-gamma association, as well as receptor-mediated cytolytic activity and calcium responses. Surprisingly, the R/G mutant still activated MAPKs and the NF-kappaB pathway and selectively stimulated the production of MIP1alpha, but not that of IFN-gamma or IL-8. In conclusion, we provide evidence that the activating functions of 2DL4 can be compartmentalized into two distinct structural modules: 1) through transmembrane association with FcepsilonRI-gamma; and 2) through another receptor domain independent of the transmembrane arginine.

Detrimental effects of nicotine on thioacetamide-induced liver injury in mice.

PubMed

Zhou, Zixiong; Park, Surim; Kim, Jong Won; Zhao, Jing; Lee, Moo-Yeol; Choi, Kyung Chul; Lim, Chae Woong; Kim, Bumseok

2017-09-01

Nicotine exerts a number of physiological effects. The purpose of this study was to determine the effects of nicotine on thioacetamide (TAA)-induced liver fibrosis in mice. For in vivo experiments, hepatic fibrosis was induced by TAA (0.25 g/kg, i.p.) three times a week for 6 weeks. Mice of TAA treated groups were administered daily with distilled water and nicotine (50 or 100 μg/mL) via gastrogavage throughout the experimental period. For in vitro experiments, HepG2 (human liver cancer cell line) and LX-2 (human hepatic stellate cell line) were used to determine oxidative stress and fibrosis, respectively. Compared to control groups, TAA treated groups had significantly differences in serum alanine transferase and aspartate aminotransferase levels and nicotine accentuated liver injury. Moreover, nicotine increased the mRNA levels of TAA-induced transforming growth factor-β (TGF-β) and collagen type I alpha 1 in the liver. Nicotine also increased TAA-induced oxidative stress. Histological examination confirmed that nicotine aggravated the degree of fibrosis caused by TAA treatment. Additionally, nicotine enhanced hepatic stellate cell activation via promoting the expression of α-smooth muscle actin. Oral administration of nicotine significantly aggravated TAA-induced hepatic fibrosis in mice through enhancing TGF-β secretion and TAA-induced oxidative stress. The increase in TGF-β levels might be associated with the strengthening of oxidative processes, subsequently leading to increased hepatic stellate cell activation and extracellular matrix deposition. These results suggest that patients with liver disease should be advised to abandon smoking since nicotine may exacerbate hepatic fibrosis.