Science.gov

Sample records for pathway controls cytoprotection

  1. Radioadaptive Cytoprotective Pathways in the Mouse Retina

    NASA Technical Reports Server (NTRS)

    Zanello, Susana B.; Wotring, V.; Theriot, C.; Ploutz-Snyder, R.; Zhang, Y.; Wu, H.

    2010-01-01

    Exposure to cosmic radiation implies a risk of tissue degeneration. Radiation retinopathy is a complication of radiotherapy and exhibits common features with other retinopathies and neuropathies. Exposure to a low radiation dose elicits protective cellular events (radioadaptive response), reducing the stress of a subsequent higher dose. To assess the risk of radiation-induced retinal changes and the extent to which a small priming dose reduces this risk, we used a mouse model exposed to a source of Cs-137-gamma radiation. Gene expression profiling of retinas from non-irradiated control C57BL/6J mice (C) were compared to retinas from mice treated with a low 50 mGy dose (LD), a high 6 Gy dose (HD), and a combined treatment of 50 mGy (priming) and 6 Gy (challenge) doses (LHD). Whole retina RNA was isolated and expression analysis for selected genes performed by RTqPCR. Relevant target genes associated with cell death/survival, oxidative stress, cellular stress response and inflammation pathways, were analyzed. Cellular stress response genes were upregulated at 4 hr after the challenge dose in LHD retinas (Sirt1: 1.5 fold, Hsf1: 1.7 fold, Hspa1a: 2.5 fold; Hif1a: 1.8 fold, Bag1: 1.7). A similar trend was observed in LD animals. Most antioxidant enzymes (Hmox1, Sod2, Prdx1, Cygb, Cat1) and inflammatory mediators (NF B, Ptgs2 and Tgfb1) were upregulated in LHD and LD retinas. Expression of the pro-survival gene Bcl2 was upregulated in LD (6-fold) and LHD (4-fold) retinas. In conclusion, cytoprotective gene networks activation in the retina suggests a radioadaptive response to a priming irradiation dose, with mitigation of the deleterious effects of a subsequent high dose exposure. The enhancement of these cytoprotective mechanisms has potential value as a countermeasure to ocular alterations caused by radiation alone or in combination with other factors in spaceflight environments.

  2. Cytoprotective pathways in the vascular endothelium. Do they represent a viable therapeutic target?

    PubMed

    Mason, Justin C

    2016-11-01

    The vascular endothelium is a critical interface, which separates the organs from the blood and its contents. The endothelium has a wide variety of functions and maintenance of endothelial homeostasis is a multi-dimensional active process, disruption of which has potentially deleterious consequences if not reversed. Vascular injury predisposes to endothelial apoptosis, dysfunction and development of atherosclerosis. Endothelial dysfunction is an end-point, a central feature of which is increased ROS generation, a reduction in endothelial nitric oxide synthase and increased nitric oxide consumption. A dysfunctional endothelium is a common feature of diseases including rheumatoid arthritis, systemic lupus erythematosus, diabetes mellitus and chronic renal impairment. The endothelium is endowed with a variety of constitutive and inducible mechanisms that act to minimise injury and facilitate repair. Endothelial cytoprotection can be enhanced by exogenous factors such as vascular endothelial growth factor, prostacyclin and laminar shear stress. Target genes include endothelial nitric oxide synthase, heme oxygenase-1, A20 and anti-apoptotic members of the B cell lymphoma protein-2 family. In light of the importance of endothelial function, and the link between its disruption and the risk of atherothrombosis, interest has focused on therapeutic conditioning and reversal of endothelial dysfunction. A detailed understanding of cytoprotective signalling pathways, their regulation and target genes is now required to identify novel therapeutic targets. The ultimate aim is to add vasculoprotection to current therapeutic strategies for systemic inflammatory diseases, in an attempt to reduce vascular injury and prevent or retard atherogenesis. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Characterization of the cancer chemopreventive NRF2-dependent gene battery in human keratinocytes: demonstration that the KEAP1-NRF2 pathway, and not the BACH1-NRF2 pathway, controls cytoprotection against electrophiles as well as redox-cycling compounds.

    PubMed

    MacLeod, A Kenneth; McMahon, Michael; Plummer, Simon M; Higgins, Larry G; Penning, Trevor M; Igarashi, Kazuhiko; Hayes, John D

    2009-09-01

    To better understand the role of transcription factor NF-E2-related factor (NRF) 2 in the human and its contribution to cancer chemoprevention, we have knocked down its negative regulators, Kelch-like ECH-associated protein 1 (KEAP1) and broad-complex, tramtrack and bric à brac and cap'n'collar homology 1 (BACH1), in HaCaT keratinocytes. Whole-genome microarray revealed that knockdown of KEAP1 resulted in 23 messenger RNAs (mRNAs) being up-regulated > or = 2.0-fold. mRNA for aldo-keto reductase (AKR) 1B10, AKR1C1, AKR1C2 and AKR1C3 were induced to the greatest extent, showing increases of between 12- and 16-fold, whereas mRNA for glutamate-cysteine ligase catalytic and modifier subunits, NAD(P)H:quinone oxidoreductase-1 and haem oxygenase-1 (HMOX1) were induced between 2.0- and 4.8-fold. Knockdown of BACH1 increased HMOX1 135-fold but induced the other genes examined to a maximum of only 2.7-fold. Activation of NRF2, by KEAP1 knockdown, caused a 75% increase in the amount of glutathione in HaCaT cells and a 1.4- to 1.6-fold increase in their resistance to the electrophiles acrolein, chlorambucil and cumene hydroperoxide (CuOOH), as well as the redox-cycling agent menadione. Inhibition of glutathione synthesis during KEAP1 knockdown, by treatment with buthionine sulfoximine, abrogated resistance to acrolein, chlorambucil and CuOOH, but not to menadione. In contrast, knockdown of BACH1 did not increase glutathione levels or resistance to xenobiotics. Knockdown of NRF2 in HaCaT cells decreased glutathione to approximately 80% of normal homeostatic levels and similarly reduced their tolerance of electrophiles. Thus, the KEAP1-NRF2 pathway determines resistance to electrophiles and redox-cycling compounds in human keratinocytes through glutathione-dependent and glutathione-independent mechanisms. This study also shows that AKR1B10, AKR1C1 and AKR1C2 proteins have potential utility as biomarkers for NRF2 activation in the human.

  4. H-ferritin ferroxidase induces cytoprotective pathways and inhibits microvascular stasis in transgenic sickle mice.

    PubMed

    Vercellotti, Gregory M; Khan, Fatima B; Nguyen, Julia; Chen, Chunsheng; Bruzzone, Carol M; Bechtel, Heather; Brown, Graham; Nath, Karl A; Steer, Clifford J; Hebbel, Robert P; Belcher, John D

    2014-01-01

    Hemolysis, oxidative stress, inflammation, vaso-occlusion, and organ infarction are hallmarks of sickle cell disease (SCD). We have previously shown that increases in heme oxygenase-1 (HO-1) activity detoxify heme and inhibit vaso-occlusion in transgenic mouse models of SCD. HO-1 releases Fe(2+) from heme, and the ferritin heavy chain (FHC) ferroxidase oxidizes Fe(2+) to catalytically inactive Fe(3+) inside ferritin. FHC overexpression has been shown to be cytoprotective. In this study, we hypothesized that overexpression of FHC and its ferroxidase activity will inhibit inflammation and microvascular stasis in transgenic SCD mice in response to plasma hemoglobin. We utilized a Sleeping Beauty (SB) transposase plasmid to deliver a human wild-type-ferritin heavy chain (wt-hFHC) transposable element by hydrodynamic tail vein injections into NY1DD SCD mice. Control SCD mice were infused with the same volume of lactated Ringer's solution (LRS) or a human triple missense FHC (ms-hFHC) plasmid with no ferroxidase activity. 8 weeks later, LRS-injected mice had ~40% microvascular stasis (% non-flowing venules) 1 h after infusion of stroma-free hemoglobin, while mice overexpressing wt-hFHC had only 5% stasis (p < 0.05), and ms-hFHC mice had 33% stasis suggesting vascular protection by ferroxidase active wt-hFHC. The wt-hFHC SCD mice had marked increases in splenic hFHC mRNA and hepatic hFHC protein, ferritin light chain (FLC), 5-aminolevulinic acid synthase (ALAS), heme content, ferroportin, nuclear factor erythroid 2-related factor 2 (Nrf2), and HO-1 activity and protein. There was also a decrease in hepatic activated nuclear factor-kappa B (NF-κB) phospho-p65 and vascular cell adhesion molecule-1 (VCAM-1). Inhibition of HO-1 activity with tin protoporphyrin demonstrated HO-1 was not essential for the protection by wt-hFHC. We conclude that wt-hFHC ferroxidase activity enhances cytoprotective Nrf2-regulated proteins including HO-1, thereby resulting in decreased NF

  5. H-ferritin ferroxidase induces cytoprotective pathways and inhibits microvascular stasis in transgenic sickle mice

    PubMed Central

    Vercellotti, Gregory M.; Khan, Fatima B.; Nguyen, Julia; Chen, Chunsheng; Bruzzone, Carol M.; Bechtel, Heather; Brown, Graham; Nath, Karl A.; Steer, Clifford J.; Hebbel, Robert P.; Belcher, John D.

    2014-01-01

    Hemolysis, oxidative stress, inflammation, vaso-occlusion, and organ infarction are hallmarks of sickle cell disease (SCD). We have previously shown that increases in heme oxygenase-1 (HO-1) activity detoxify heme and inhibit vaso-occlusion in transgenic mouse models of SCD. HO-1 releases Fe2+ from heme, and the ferritin heavy chain (FHC) ferroxidase oxidizes Fe2+ to catalytically inactive Fe3+ inside ferritin. FHC overexpression has been shown to be cytoprotective. In this study, we hypothesized that overexpression of FHC and its ferroxidase activity will inhibit inflammation and microvascular stasis in transgenic SCD mice in response to plasma hemoglobin. We utilized a Sleeping Beauty (SB) transposase plasmid to deliver a human wild-type-ferritin heavy chain (wt-hFHC) transposable element by hydrodynamic tail vein injections into NY1DD SCD mice. Control SCD mice were infused with the same volume of lactated Ringer’s solution (LRS) or a human triple missense FHC (ms-hFHC) plasmid with no ferroxidase activity. 8 weeks later, LRS-injected mice had ~40% microvascular stasis (% non-flowing venules) 1 h after infusion of stroma-free hemoglobin, while mice overexpressing wt-hFHC had only 5% stasis (p < 0.05), and ms-hFHC mice had 33% stasis suggesting vascular protection by ferroxidase active wt-hFHC. The wt-hFHC SCD mice had marked increases in splenic hFHC mRNA and hepatic hFHC protein, ferritin light chain (FLC), 5-aminolevulinic acid synthase (ALAS), heme content, ferroportin, nuclear factor erythroid 2-related factor 2 (Nrf2), and HO-1 activity and protein. There was also a decrease in hepatic activated nuclear factor-kappa B (NF-κB) phospho-p65 and vascular cell adhesion molecule-1 (VCAM-1). Inhibition of HO-1 activity with tin protoporphyrin demonstrated HO-1 was not essential for the protection by wt-hFHC. We conclude that wt-hFHC ferroxidase activity enhances cytoprotective Nrf2-regulated proteins including HO-1, thereby resulting in decreased NF

  6. Heme oxygenase-1: a provenance for cytoprotective pathways in the kidney and other tissues.

    PubMed

    Nath, K A

    2006-08-01

    Heme oxygenase (HO) is the rate-limiting enzyme in the degradation of heme, converting heme to biliverdin, during which iron is released and carbon monoxide (CO) is emitted; biliverdin is subsequently converted to bilirubin by biliverdin reductase. At least two isozymes possess HO activity: HO-1 represents the isozyme induced by diverse stressors, including ischemia, nephrotoxins, cytokines, endotoxin, oxidants, and vasoactive substances; HO-2 is the constitutive, glucocorticoid-inducible isozyme. HO-1 is upregulated in the kidney in assorted conditions and diseases. Interest in HO is driven by the capacity of this system to protect the kidney against injury, a capacity likely reflecting, at least in part, the cytoprotective properties of its products: in relatively low concentrations, CO exerts vasorelaxant, antiapoptotic, and anti-inflammatory effects while bile pigments are antioxidant and anti-inflammatory metabolites. This article reviews the HO system and the extent to which it influences the function of the healthy kidney; it summarizes conditions and stimuli that elicit HO-1 in the kidney; and it explores the significance of renal expression of HO-1 as induced by ischemia, nephrotoxins, nephritides, transplantation, angiotensin II, and experimental diabetes. This review also points out the tissue specificity of the HO system, and the capacity of HO-1 to induce renal injury in certain settings. Studies of HO in other tissues are discussed insofar as they aid in elucidating the physiologic and pathophysiologic significance of the HO system in the kidney.

  7. Quinone Methide Bioactivation Pathway: Contribution to Toxicity and/or Cytoprotection?

    PubMed Central

    Bolton, Judy L.

    2014-01-01

    The formation of quinone methides (QMs) from either direct 2-electron oxidation of 2- or 4-alkylphenols, isomerization of o-quinones, or elimination of a good leaving group could explain the cytotoxic/cytoprotective effects of several drugs, natural products, as well as endogenous compounds. For example, the antiretroviral drug nevirapine and the antidiabetic agent troglitazone both induce idiosyncratic hepatotoxicity through mechanisms involving quinone methide formation. The anesthetic phencyclidine induces psychological side effects potentially through quinone methide mediated covalent modification of crucial macromolecules in the brain. Selective estrogen receptor modulators (SERMs) such as tamoxifen, toremifene, and raloxifene are metabolized to quinone methides which could potentially contribute to endometrial carcinogenic properties and/or induce detoxification enzymes and enhance the chemopreventive effects of these SERMs. Endogenous estrogens and/or estrogens present in estrogen replacement formulations are also metabolized to catechols and further oxidized to o-quinones which can isomerize to quinone methides. Both estrogen quinoids could cause DNA damage which could enhance hormone dependent cancer risk. Natural products such as the food and flavor agent eugenol can be directly oxidized to a quinone methide which may explain the toxic effects of this natural compound. Oral toxicities associated with chewing areca quid could be the result of exposure to hydroxychavicol through initial oxidation to an o-quinone which isomerizes to a p-quinone methide. Similar o-quinone to p-quinone methide isomerization reactions have been reported for the ubiquitous flavonoid quercetin which needs to be taken into consideration when evaluating risk-benefit assessments of these natural products. The resulting reaction of these quinone methides with proteins, DNA, and/or resulting modulation of gene expression may explain the toxic and/or beneficial effects of the parent

  8. Pathways for ischemic cytoprotection: Role of sirtuins in caloric restriction, resveratrol, and ischemic preconditioning

    PubMed Central

    Morris, Kahlilia C; Lin, Hung Wen; Thompson, John W; Perez-Pinzon, Miguel A

    2011-01-01

    Caloric restriction (CR), resveratrol, and ischemic preconditioning (IPC) have been shown to promote protection against ischemic injury in the heart and brain, as well as in other tissues. The activity of sirtuins, which are enzymes that modulate diverse biologic processes, seems to be vital in the ability of these therapeutic modalities to prevent against cellular dysfunction and death. The protective mechanisms of the yeast Sir2 and the mammalian homolog sirtuin 1 have been extensively studied, but the involvement of other sirtuins in ischemic protection is not yet clear. We examine the roles of mammalian sirtuins in modulating protective pathways against oxidative stress, energy depletion, excitotoxicity, inflammation, DNA damage, and apoptosis. Although many of these sirtuins have not been directly implicated in ischemic protection, they may have unique roles in enhancing function and preventing against stress-mediated cellular damage and death. This review will include in-depth analyses of the roles of CR, resveratrol, and IPC in activating sirtuins and in mediating protection against ischemic damage in the heart and brain. PMID:21224864

  9. A novel shogaol analog suppresses cancer cell invasion and inflammation, and displays cytoprotective effects through modulation of NF-κB and Nrf2-Keap1 signaling pathways

    SciTech Connect

    Gan, Fei-Fei; Ling, Hui; Ang, Xiaohui; Reddy, Shridhivya A.; Lee, Stephanie S-H.; Yang, Hong; Tan, Sock-Hoon; Hayes, John D.; Chui, Wai-Keung; Chew, Eng-Hui

    2013-11-01

    Natural compounds containing vanilloid and Michael acceptor moieties appear to possess anti-cancer and chemopreventive properties. The ginger constituent shogaol represents one such compound. In this study, the anti-cancer potential of a synthetic novel shogaol analog 3-phenyl-3-shogaol (3-Ph-3-SG) was assessed by evaluating its effects on signaling pathways. At non-toxic concentrations, 3-Ph-3-SG suppressed cancer cell invasion in MDA-MB-231 and MCF-7 breast carcinoma cells through inhibition of PMA-activated MMP-9 expression. At similar concentrations, 3-Ph-3-SG reduced expression of the inflammatory mediators nitric oxide (NO), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and prostanglandin-E{sub 2} (PGE{sub 2}) in RAW 264.7 macrophage-like cells. Inhibition of cancer cell invasion and inflammation by 3-Ph-3-SG were mediated through suppression of the nuclear factor-kappaB (NF-κB) signaling pathway. The 3-Ph-3-SG also demonstrated cytoprotective effects by inducing the antioxidant response element (ARE)-driven genes NAD(P)H quinone oxidoreductase-1 (NQO1) and heme oxygenase-1 (HO-1). Cytoprotection by 3-Ph-3-SG was achieved at least partly through modification of cysteine residues in the E3 ubiquitin ligase substrate adaptor Kelch-like ECH-associated protein 1 (Keap1), which resulted in accumulation of transcription factor NF-E2 p45-related factor 2 (Nrf2). The activities of 3-Ph-3-SG were comparable to those of 6-shogaol, the most abundant naturally-occurring shogaol, and stronger than those of 4-hydroxyl-null deshydroxy-3-phenyl-3-shogaol, which attested the importance of the 4-hydroxy substituent in the vanilloid moiety for bioactivity. In summary, 3-Ph-3-SG is shown to possess activities that modulate stress-associated pathways relevant to multiple steps in carcinogenesis. Therefore, it warrants further investigation of this compound as a promising candidate for use in chemotherapeutic and chemopreventive strategies. - Highlights:

  10. Cytoprotective effect of kaempferol against palmitic acid-induced pancreatic β-cell death through modulation of autophagy via AMPK/mTOR signaling pathway.

    PubMed

    Varshney, Ritu; Gupta, Sumeet; Roy, Partha

    2017-02-22

    Lipotoxicity of pancreatic β-cells is the pathological manifestation of obesity-linked type II diabetes. We intended to determine the cytoprotective effect of kaempferol on pancreatic β-cells undergoing apoptosis in palmitic acid (PA)-stressed condition. The data showed that kaempferol treatment increased cell viability and anti-apoptotic activity in PA-stressed RIN-5F cells and murine pancreatic islets. Furthermore, kaempferol's ability to instigate autophagy was illustrated by MDC-LysoTracker red staining and TEM analysis which corroborated well with the observed increase in LC3 puncta and LC3-II protein expressions along with the concomitant decline in p62 expression. Apart from this, the data showed that kaempferol up/down-regulates AMPK/mTOR phosphorylation respectively. Subsequently, upon inhibition of AMPK phosphorylation by AMPK inhibitors, kaempferol mediated autophagy was abolished which further led to the decline in β-cell survival. Such observations collectively lead to the conclusion that, kaempferol exerts its cytoprotective role against lipotoxicity by activation of autophagy via AMPK/mTOR pathway.

  11. The Marburg virus VP24 protein interacts with Keap1 to activate the cytoprotective antioxidant response pathway.

    PubMed

    Edwards, Megan R; Johnson, Britney; Mire, Chad E; Xu, Wei; Shabman, Reed S; Speller, Lauren N; Leung, Daisy W; Geisbert, Thomas W; Amarasinghe, Gaya K; Basler, Christopher F

    2014-03-27

    Kelch-like ECH-associated protein 1 (Keap1) is a ubiquitin E3 ligase specificity factor that targets transcription factor nuclear factor (erythroid-derived 2)-like 2 (Nrf2) for ubiquitination and degradation. Disrupting Keap1-Nrf2 interaction stabilizes Nrf2, resulting in Nrf2 nuclear accumulation, binding to antioxidant response elements (AREs), and transcription of cytoprotective genes. Marburg virus (MARV) is a zoonotic pathogen that likely uses bats as reservoir hosts. We demonstrate that MARV protein VP24 (mVP24) binds the Kelch domain of either human or bat Keap1. This binding is of high affinity and 1:1 stoichiometry and activates Nrf2. Modeling based on the Zaire ebolavirus (EBOV) VP24 (eVP24) structure identified in mVP24 an acidic loop (K-loop) critical for Keap1 interaction. Transfer of the K-loop to eVP24, which otherwise does not bind Keap1, confers Keap1 binding and Nrf2 activation, and infection by MARV, but not EBOV, activates ARE gene expression. Therefore, MARV targets Keap1 to activate Nrf2-induced cytoprotective responses during infection.

  12. Pirarubicin induces an autophagic cytoprotective response through suppression of the mammalian target of rapamycin signaling pathway in human bladder cancer cells

    SciTech Connect

    Li, Kuiqing; Chen, Xu; Liu, Cheng; Gu, Peng; Li, Zhuohang; Wu, Shaoxu; Xu, Kewei; Lin, Tianxin; Huang, Jian

    2015-05-01

    Pirarubicin is widely used in intravesical chemotherapy for bladder cancer, but its efficacy is limited due to drug resistance; the mechanism has not been well studied. Emerging evidence shows that autophagy can be a novel target for cancer therapy. This study aimed to investigate the role of autophagy in pirarubicin-treated bladder cancer cells. Bladder cancer cells EJ and J82 were treated with pirarubicin, siRNA, 3-methyladenine or hydroxychloroquine. Cell proliferation and apoptosis were tested by cell survival assay and flow cytometric analysis, respectively. Autophagy was evaluated by immunoblotting before and after the treatments. The phosphorylated mammalian target of rapamycin, serine/threonine kinase p70 S6 kinase, and eukaryotic translation initiation factor 4E binding protein 1 were also investigated by immunoblotting. We found that pirarubicin could induce autophagy in bladder cancer cells. Inhibition of autophagy by 3-methyladenine, hydroxychloroquine or knockdown of autophagy related gene 3 significantly increased apoptosis in pirarubicin-treated bladder cancer cells. Pirarubicin-induced autophagy was mediated via the mTOR/p70S6K/4E-BP1 signaling pathway. In conclusion, autophagy induced by pirarubicin plays a cytoprotective role in bladder cancer cells, suggesting that inhibition of autophagy may improve efficacy over traditional pirarubicin chemotherapy in bladder cancer patients. - Highlights: • Pirarubicin induced autophagy in bladder cancer cells. • Inhibition of autophagy enhanced pirarubicin-induced apoptosis. • Pirarubicin induced autophagy through inhibition of mTOR signaling pathway.

  13. Epigenetics and cytoprotection with heat acclimation.

    PubMed

    Horowitz, Michal

    2016-03-15

    Studying "phenotypic plasticity" involves comparison of traits expressed in response to environmental fluctuations and aims to understand tolerance and survival in new settings. Reversible phenotypic changes that enable individuals to match their phenotype to environmental demands throughout life can be artificially induced, i.e., acclimation or occur naturally, i.e., acclimatization. The onset and achievement of acclimatory homeostasis are determined by molecular programs that induce the acclimated transcriptome. In heat acclimation, much evidence suggests that epigenetic mechanisms are powerful players in these processes. Epigenetic mechanisms affect the accessibility of the DNA to transcription factors, thereby regulating gene expression and controlling the phenotype. The heat-acclimated phenotype confers cytoprotection against novel stressors via cross-tolerance mechanisms, by attenuation of the initial damage and/or by accelerating spontaneous recovery through the release of help signals. This indispensable acclimatory feature has a memory and can be rapidly reestablished after the loss of acclimation and the return to the physiological preacclimated phenotype. The transcriptional landscape of the deacclimated phenotype includes constitutive transcriptional activation of epigenetic bookmarks. Heat shock protein (HSP) 70/HSP90/heat shock factor 1 memory protocol demonstrated constitutive histone H4 acetylation on hsp70 and hsp90 promotors. Novel players in the heat acclimation setup are poly(ADP-ribose)ribose polymerase 1 affecting chromatin condensation, DNA linker histones from the histone H1 cluster, and transcription factors associated with the P38 pathway. We suggest that these orchestrated responses maintain euchromatin and proteostasis during deacclimation and predispose to rapid reacclimation and cytoprotection. These mechanisms represent within-life epigenetic adaptations and cytoprotective memory. Copyright © 2016 the American Physiological Society.

  14. Cellular metabolic and autophagic pathways: traffic control by redox signaling.

    PubMed

    Dodson, Matthew; Darley-Usmar, Victor; Zhang, Jianhua

    2013-10-01

    It has been established that the key metabolic pathways of glycolysis and oxidative phosphorylation are intimately related to redox biology through control of cell signaling. Under physiological conditions glucose metabolism is linked to control of the NADH/NAD redox couple, as well as providing the major reductant, NADPH, for thiol-dependent antioxidant defenses. Retrograde signaling from the mitochondrion to the nucleus or cytosol controls cell growth and differentiation. Under pathological conditions mitochondria are targets for reactive oxygen and nitrogen species and are critical in controlling apoptotic cell death. At the interface of these metabolic pathways, the autophagy-lysosomal pathway functions to maintain mitochondrial quality and generally serves an important cytoprotective function. In this review we will discuss the autophagic response to reactive oxygen and nitrogen species that are generated from perturbations of cellular glucose metabolism and bioenergetic function. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Cellular Metabolic and Autophagic Pathways: Traffic Control by Redox Signaling

    PubMed Central

    Dodson, Matthew; Darley-Usmar, Victor; Zhang, Jianhua

    2013-01-01

    It has been established that the key metabolic pathways of glycolysis and oxidative phosphorylation are intimately related to redox biology through control of cell signaling. Under physiological conditions glucose metabolism is linked to control of the NADH/NAD redox couple, as well as providing the major reductant, NADPH, for thiol-dependent antioxidant defenses. Retrograde signaling from the mitochondrion to the nucleus or cytosol controls cell growth and differentiation. Under pathological conditions mitochondria are targets for reactive oxygen and nitrogen species and are critical in controlling apoptotic cell death. At the interface of these metabolic pathways, the autophagy-lysosomal pathway functions to maintain mitochondrial quality, and generally serves an important cytoprotective function. In this review we will discuss the autophagic response to reactive oxygen and nitrogen species that are generated from perturbations of cellular glucose metabolism and bioenergetic function. PMID:23702245

  16. SKF-96365 activates cytoprotective autophagy to delay apoptosis in colorectal cancer cells through inhibition of the calcium/CaMKIIγ/AKT-mediated pathway.

    PubMed

    Jing, Zhao; Sui, Xinbing; Yao, Junlin; Xie, Jiansheng; Jiang, Liming; Zhou, Yubin; Pan, Hongming; Han, Weidong

    2016-03-28

    Store-operated Ca(2+) entry (SOCE) inhibitors are emerging as an attractive new generation of anti-cancer drugs. Here, we report that SKF-96365, an SOCE inhibitor, exhibits potent anti-neoplastic activity by inducing cell-cycle arrest and apoptosis in colorectal cancer cells. In the meantime, SKF-96365 also induces cytoprotective autophagy to delay apoptosis by preventing the release of cytochrome c (cyt c) from the mitochondria into the cytoplasm. Mechanistically, SKF-96365 treatment inhibited the calcium/calmodulin-dependent protein kinase IIγ (CaMKIIγ)/AKT signaling cascade in vitro and in vivo. Overexpression of CaMKIIγ or AKT abolished the effects of SKF-96365 on cancer cells, suggesting a critical role of the CaMKIIγ/AKT signaling pathway in SFK-96365-induced biological effects. Moreover, Hydroxychloroquine (HCQ), an FDA-approved drug used to inhibit autophagy, could significantly augment the anti-cancer effect of SFK-96365 in a mouse xenograft model. To our best knowledge, this is the first report to demonstrate that calcium/CaMKIIγ/AKT signaling can regulate apoptosis and autophagy simultaneously in cancer cells, and the combination of the SOCE inhibitor SKF-96365 with autophagy inhibitors represents a promising strategy for treating patients with colorectal cancer. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  17. Seaweed extracts and unsaturated fatty acid constituents from the green alga Ulva lactuca as activators of the cytoprotective Nrf2-ARE pathway.

    PubMed

    Wang, Rui; Paul, Valerie J; Luesch, Hendrik

    2013-04-01

    Increased amounts of reactive oxygen species (ROS) have been implicated in many pathological conditions, including cancer. The major machinery that the cell employs to neutralize excess ROS is through the activation of the antioxidant-response element (ARE) that controls the activation of many phase II detoxification enzymes. The transcription factor that recognizes the ARE, Nrf2, can be activated by a variety of small molecules, most of which contain an α,β-unsaturated carbonyl system. In the pursuit of chemopreventive agents from marine organisms, we built, fractionated, and screened a library of 30 field-collected eukaryotic algae from Florida. An edible green alga, Ulva lactuca, yielded multiple active fractions by ARE-luciferase reporter assay. We isolated three monounsaturated fatty acid (MUFA) derivatives as active components, including a new keto-type C18 fatty acid (1), the corresponding shorter chain C16 acid (2), and an amide derivative (3) of the C18 acid. Their chemical structures were elucidated by NMR and mass spectrometry. All three contain the conjugated enone motif between C7 and C9, which is thought to be responsible for the ARE activity. Subsequent biological studies focused on 1, the most active and abundant ARE activator isolated. C18 acid 1 induced the expression of ARE-regulated cytoprotective genes, including NAD(P)H:quinone oxidoreductase 1, heme oxygenase 1, thioredoxin reductase 1, both subunits of the glutamate-cysteine ligase (catalytic subunit and modifier subunit), and the cystine/glutamate exchange transporter, in IMR-32 human neuroblastoma cells. Its cellular activity requires the presence of Nrf2 and PI3K function, based on RNA interference and pharmacological inhibitor studies, respectively. Treatment with 1 led only to Nrf2 activation, and not the increase in production of NRF2 mRNA. To test its ARE activity and cytoprotective potential in vivo, we treated mice with a single dose of a U. lactuca fraction that was enriched with

  18. [Role of membrane lipids in myocardial cytoprotection

    NASA Technical Reports Server (NTRS)

    Grynberg, A.

    2000-01-01

    The cardiomyocyte capacity to regulate ATP production to face any change in energy demand is a major determinant of cardiac function. This process is based on a balanced fatty acid (FA) metabolism, because FA is the main fuel of the heart, although the most expensive one in oxygen. The pathway is, however, weakly controlled by the cardiac myocyte which can well regulate FA mitochondrial entry but not cell FA uptake. For this reason, several pathological situations often result from either harmful accumulation of FA and derivatives or excess FA-oxidation. Control of the FA/glucose balance by decreased energy production from FA would thus offer an alternative strategy in the treatment of ischaemia, providing the cardiomyocytes weak ability in handling the non-metabolised FA is controlled. The initiation and the regulation of cardiac contraction both result from membrane activity; the other major role of lipids in the heart is their contribution to membrane homeostasis through phospholipid synthesis pathways and phospholipases. The anti-anginal activity of Trimetazidine, reported as a cytoprotective effect without a haemo-dynamic component; is associated with reduced use of FA for energy. However, accumulation of FA and derivatives has never been observed. Trimetazidine is reported to increase significantly the synthesis of phospholipids without influencing the other lipid classes, thus increasing the incorporation of FA in membrane structures. This cytoprotection appears to be based on the redirection of the use of FA to phospholipid synthesis, which would decrease their availability for energy production. This class of compounds, with the same properties as Trimetazidine, offers a metabolic approach to the treatment of ischaemia.

  19. [Role of membrane lipids in myocardial cytoprotection

    NASA Technical Reports Server (NTRS)

    Grynberg, A.

    2000-01-01

    The cardiomyocyte capacity to regulate ATP production to face any change in energy demand is a major determinant of cardiac function. This process is based on a balanced fatty acid (FA) metabolism, because FA is the main fuel of the heart, although the most expensive one in oxygen. The pathway is, however, weakly controlled by the cardiac myocyte which can well regulate FA mitochondrial entry but not cell FA uptake. For this reason, several pathological situations often result from either harmful accumulation of FA and derivatives or excess FA-oxidation. Control of the FA/glucose balance by decreased energy production from FA would thus offer an alternative strategy in the treatment of ischaemia, providing the cardiomyocytes weak ability in handling the non-metabolised FA is controlled. The initiation and the regulation of cardiac contraction both result from membrane activity; the other major role of lipids in the heart is their contribution to membrane homeostasis through phospholipid synthesis pathways and phospholipases. The anti-anginal activity of Trimetazidine, reported as a cytoprotective effect without a haemo-dynamic component; is associated with reduced use of FA for energy. However, accumulation of FA and derivatives has never been observed. Trimetazidine is reported to increase significantly the synthesis of phospholipids without influencing the other lipid classes, thus increasing the incorporation of FA in membrane structures. This cytoprotection appears to be based on the redirection of the use of FA to phospholipid synthesis, which would decrease their availability for energy production. This class of compounds, with the same properties as Trimetazidine, offers a metabolic approach to the treatment of ischaemia.

  20. Tissue-level cytoprotection.

    PubMed

    Hightower, L E; Brown; Renfro, J L; Perdrizet, G A; Rewinski, M; Guidon, P T; Mistry, T; House, S D

    2000-11-01

    In vitro and ex vivo tissue models provide a useful level of biological organization for cytoprotection studies positioned between cultured cells and intact animals. We have used 2 such models, primary tissue cultures of winter flounder renal secretory epithelium and ex vivo preparations of rat intestinal tissues, the latter to access the microcirculation of exposed mesentery tissues. Herein we discuss studies indicating that differentiated functions are altered in thermotolerant or cytoprotected tissues. These functions include transepithelial transport in renal epithelium and attachment and transmigration of leukocytes across vascular endothelium in response to mediators of inflammation. Evidence pointing to inflammation as a major venue for the heat shock response in vertebrates continues to mount. One such venue is wound healing. Heat shock proteins are induced early in wound responses, and some are released into the extracellular wound fluid where they appear to function as proinflammatory cytokines. However, within responding cells in the wound, heat shock proteins contribute to the acquisition of a state of cytoprotection that protects cells from the hostile environment of the wound, an environment created to destroy pathogens and essentially sterilize the wound. We propose that the cytoprotected state is an anti-inflammatory state that contributes to limiting the inflammatory response; that is, it serves as a brake on inflammation.

  1. Tissue-level cytoprotection

    PubMed Central

    Hightower, L.E.; Brown, M.A.; Renfro, J.L.; Perdrizet, G.A.; Rewinski, M.; Guidon, P.T.; Mistry, T.; House, S.D.

    2000-01-01

    In vitro and ex vivo tissue models provide a useful level of biological organization for cytoprotection studies positioned between cultured cells and intact animals. We have used 2 such models, primary tissue cultures of winter flounder renal secretory epithelium and ex vivo preparations of rat intestinal tissues, the latter to access the microcirculation of exposed mesentery tissues. Herein we discuss studies indicating that differentiated functions are altered in thermotolerant or cytoprotected tissues. These functions include transepithelial transport in renal epithelium and attachment and transmigration of leukocytes across vascular endothelium in response to mediators of inflammation. Evidence pointing to inflammation as a major venue for the heat shock response in vertebrates continues to mount. One such venue is wound healing. Heat shock proteins are induced early in wound responses, and some are released into the extracellular wound fluid where they appear to function as proinflammatory cytokines. However, within responding cells in the wound, heat shock proteins contribute to the acquisition of a state of cytoprotection that protects cells from the hostile environment of the wound, an environment created to destroy pathogens and essentially sterilize the wound. We propose that the cytoprotected state is an anti-inflammatory state that contributes to limiting the inflammatory response; that is, it serves as a brake on inflammation. PMID:11189445

  2. Neopterin as a potential cytoprotective brain molecule.

    PubMed

    Ghisoni, Karina; Martins, Roberta de Paula; Barbeito, Luis; Latini, Alexandra

    2015-12-01

    Neopterin, a byproduct of the tetrahydrobiopterin de novo pathway, is found in increased levels in cerebrospinal fluid and plasma and significantly increases upon damage, infection or during immune system activation. The production of this compound seems almost restricted to the monocyte/macrophage linage cells, in response to interferon-γ stimulation. However, it is unclear whether and which nervous cells are able to synthesize neopterin, respond to any stressor applied extracellularly, or even the role of the compound in the central nervous system. Here we propose a potential cytoprotective role of neopterin in the brain, and show evidence that cultured rat astrocytes are responsive to the molecule; the pterin elicited increased hemeoxygenase-1 cellular content and decreased oxidative stress induced by mitochondrial dysfunction. Further studies are needed to clarify neopterin's cytoprotective effects in the central nervous system, and its potential role in different neuroinflammatory diseases. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. PDT: loss of autophagic cytoprotection after lysosomal photodamage

    NASA Astrophysics Data System (ADS)

    Kessel, David; Price, Michael

    2012-02-01

    Photodynamic therapy is known to evoke both autophagy and apoptosis. Apoptosis is an irreversible death pathway while autophagy can serve a cytoprotective function. In this study, we examined two photosensitizing agents that target lysosomes, although they differ in the reactive oxygen species (ROS) formed during irradiation. With both agents, the 'shoulder' on the PDT dose-response curve was substantially attenuated, consistent with loss of a cytoprotective pathway. In contrast, this 'shoulder' is commonly observed when PDT targets mitochondria or the ER. We propose that lysosomal targets may offer the possibility of promoting PDT efficacy by eliminating a potentially protective pathway.

  4. Cytoprotective effect of neuropeptides on cancer stem cells: vasoactive intestinal peptide-induced antiapoptotic signaling.

    PubMed

    Sastry, Konduru S; Chouchane, Aouatef Ismail; Wang, Ena; Kulik, George; Marincola, Francesco M; Chouchane, Lotfi

    2017-06-01

    Cancer stem cells (CSCs) are increasingly considered to be responsible for tumor initiation, metastasis and drug resistance. The drug resistance mechanisms activated in CSCs have not been thoroughly investigated. Although neuropeptides such as vasoactive intestinal peptide (VIP) can promote tumor growth and activate antiapoptotic signaling in differentiated cancer cells, it is not known whether they can activate antiapoptotic mechanisms in CSCs. The objectives of this study are to unravel the cytoprotective effects of neuropeptides and identify antiapoptotic mechanisms activated by neuropeptides in response to anticancer drug treatment in CSCs. We enriched and purified CSCs (CD44(+/high)/CD24(-/low) or CD133(+) population) from breast and prostate cancer cell lines, and demonstrated their stemness phenotype. Of the several neuropeptides tested, only VIP could protect CSCs from drug-induced apoptosis. A functional correlation was found between drug-induced apoptosis and dephosphorylation of proapoptotic Bcl2 family protein BAD. Similarly, VIP-induced cytoprotection correlated with BAD phosphorylation at Ser112 in CSCs. Using pharmacological inhibitors and dominant-negative proteins, we showed that VIP-induced cytoprotection and BAD phosphorylation are mediated via both Ras/MAPK and PKA pathways in CSCs of prostate cancer LNCaP and C4-2 cells, but only PKA signaling was involved in CSCs of DUVIPR (DU145 prostate cancer cells ectopically expressing VIP receptor) and breast cancer MCF7 cells. As each of these pathways partially control BAD phosphorylation at Ser112, both have to be inhibited to block the cytoprotective effects of VIP. Furthermore, VIP is unable to protect CSCs that express phosphorylation-deficient mutant-BAD, suggesting that BAD phosphorylation is essential. Thus, antiapoptotic signaling by VIP could be one of the drug resistance mechanisms by which CSCs escape from anticancer therapies. Our findings suggest the potential usefulness of VIP receptor

  5. The cytoprotective effects of ethanol extract of Ecklonia cava against oxidative stress are associated with upregulation of Nrf2-mediated HO-1 and NQO-1 expression through activation of the MAPK pathway.

    PubMed

    Choi, Yung Hyun

    2016-01-01

    The aim of the present study was to examine the cytoprotective effect of Ecklonia cava against oxidative stress in C2C12 myoblasts. The ethanol extract of E. cava (EEEC) prevented hydrogen peroxide (H₂O₂)-induced inhibition of the growth of C2C12 myoblasts and exhibited scavenging activity against intracellular reactive oxygen species (ROS) induced by H₂O₂. EEEC treatment attenuated H2O2-induced comet tail formation and phospho-histone γH2A.X expression. Furthermore, EEEC treatment enhanced the level of the phosphorylated form of nuclear factor erythroid 2- related factor 2 (Nrf2) and its nuclear translocation, which was associated with the induction of heme oxygenase-1 (HO-1) and NADPH-quinone oxidoreductase 1 (NQO-1). Zinc protoporphyrin IX, a HO-1 competitive inhibitor, significantly abolished the protective effects of EEEC against H₂O₂-induced ROS generation and growth inhibition in C2C12 myoblasts. Transient transfection with Nrf2-specific small interfering RNA restored the elevated HO-1 and NQO-1 expression and the phosphorylation of Nrf2 to near normal levels. The EEEC treatment also induced the activation of mitogen-activated protein kinases (MAPKs), and specific inhibitors of MAPKs abolished upregulated HO-1 and NQO-1, as well as the phosphorylation of Nrf2. Taken together, these data suggest that EEEC attenuates oxidative stress by activating Nrf2-mediated HO-1 and inducing NQO-1 via the activation of MAPK signaling pathways.

  6. Morin exerts cytoprotective effects against oxidative stress in C2C12 myoblasts via the upregulation of Nrf2-dependent HO-1 expression and the activation of the ERK pathway.

    PubMed

    Lee, Moon Hee; Han, Min Ho; Lee, Dae-Sung; Park, Cheol; Hong, Su-Hyun; Kim, Gi-Young; Hong, Sang Hoon; Song, Kyoung Seob; Choi, Il-Whan; Cha, Hee-Jae; Choi, Yung Hyun

    2017-02-01

    In the present study, we investigated the cytoprotective efficacy of morin, a natural flavonoid, against oxidative stress and elucidated the underlying mechanisms in C2C12 myoblasts. Our results indicated that morin treatment prior to hydrogen peroxide (H2O2) exposure significantly increased cell viability and prevented the generation of reactive oxygen species. H2O2-induced comet-like DNA formation and γH2AX phosphorylation were also markedly suppressed by morin with a parallel inhibition of apoptosis in C2C12 myoblasts, suggesting that morin prevented H2O2-induced cellular DNA damage. Furthermore, morin markedly enhanced the expression of heme oxygenase-1 (HO-1) associated with the induction and phosphorylation of nuclear factor-erythroid 2-related factor 2 (Nrf2) and the inhibition of Kelch-like ECH-associated protein 1 (Keap1) expression. Notably, these events were eliminated by transient transfection with Nrf2‑specific small interfering RNA. Additional experiments demonstrated that the activation of the Nrf2/HO-1 pathway by morin was mediated by the extracellular signal‑regulated kinase (ERK) signaling cascade. This phenomenon was confirmed with suppressed Nrf2 phosphorylation and consequently diminished HO-1 expression in cells treated with a pharmacological inhibitor of ERK. Collectively, these results demonstrated that morin augments the cellular antioxidant defense capacity through the activation of Nrf2/HO‑1 signaling, which involves the activation of the ERK pathway, thereby protecting C2C12 myoblasts from H2O2-induced oxidative cytotoxicity.

  7. Geraniin exerts cytoprotective effect against cellular oxidative stress by upregulation of Nrf2-mediated antioxidant enzyme expression via PI3K/AKT and ERK1/2 pathway.

    PubMed

    Wang, Peng; Peng, Xiao; Wei, Zuo-Fu; Wei, Fu-Yao; Wang, Wei; Ma, Wei-Dong; Yao, Li-Ping; Fu, Yu-Jie; Zu, Yuan-Gang

    2015-09-01

    Geraniin, an active compound with remarkable antioxidant activity, was isolated from Geranium sibiricum. The present study aimed to investigate whether geraniin has the ability to activate Nrf2, induce antioxidant enzyme expression and protect cells from oxidative damage. The cells were pretreated with geraniin for 24h and exposed to hydrogen peroxide (H₂O₂) for 4h. Intracellular reactive oxygen species (ROS) levels, mitochondrial membrane potential and apoptosis were measured. We also investigated intracellular glutathione (GSH) levels and changes in nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated signaling cascade in cells treated with geraniin. We investigated the protective effects of geraniin against H₂O₂-induced apoptosis in HepG2 cells. Geraniin significantly reduced H₂O₂-induced oxidative damage in a dose dependent manner. Further, geraniin induced the expression of heme oxygenase-1 (HO-1), NAD(P)H quinone oxidoreductase-1 (NQO1) and level of glutathione (GSH) in a concentration- and time-dependent manner, and increased Nrf2 nuclear translocation. The Nrf2-related cytoprotective effects of geraniin were PI3K/AKT and extracellular signal-regulated protein kinase1/2 (ERK1/2) pathway-dependent. However, inhibitors of PI3K/AKT and ERK1/2 (LY294002 or U0126) not only suppressed geraniin-induced nuclear translocation of Nrf2 but also abolished the expression of HO-1, NQO1 and GSH. These results demonstrated that geraniin induced Nrf2-mediated expression of antioxidant enzymes HO-1 and NQO1, presumably via PI3K/AKT and ERK1/2 signaling pathways, thereby protecting cells from H₂O₂-induced oxidative cell death. Geraniin, at least in part, offers an antioxidant defense capacity to protect cells from the oxidative stress-related diseases. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Antioxidant and cytoprotective properties of partridgeberry polyphenols.

    PubMed

    Bhullar, Khushwant S; Rupasinghe, H P Vasantha

    2015-02-01

    Partridgeberry (Vaccinium vitis-idaea) is a polyphenol-rich berry of the Ericaceous family, grown in Newfoundland and Labrador province of Canada. The aims of this study were to identify extraction solvents for the maximum recovery of polyphenols, to establish fractionation technique for isolation of major sub-classes of polyphenols, and to evaluate antioxidant and cytoprotective properties of the partridgeberry polyphenol preparations. The acidified 70% acetone was identified as the ideal solvent for the maximum recovery of polyphenols from partridgeberry. Further, aqueous two-phase extraction, column chromatography and UPLC-MS/MS were employed to produce three partridgeberry polyphenol fractions, rich in either, anthocyanins, flavan-3-ols or flavonols. All the three PPF were potent antioxidants and displayed cytoprotective activity through the activation of nuclear factor erythroid 2-related factor 2 pathway, scavenging of reactive oxygen species, and inhibition of cellular death. The current study suggests that partridgeberry has numerous potential health implications in both prevention and amelioration of various diseases involving oxidative stress.

  9. CD47 Receptor Globally Regulates Metabolic Pathways That Control Resistance to Ionizing Radiation.

    PubMed

    Miller, Thomas W; Soto-Pantoja, David R; Schwartz, Anthony L; Sipes, John M; DeGraff, William G; Ridnour, Lisa A; Wink, David A; Roberts, David D

    2015-10-09

    Modulating tissue responses to stress is an important therapeutic objective. Oxidative and genotoxic stresses caused by ionizing radiation are detrimental to healthy tissues but beneficial for treatment of cancer. CD47 is a signaling receptor for thrombospondin-1 and an attractive therapeutic target because blocking CD47 signaling protects normal tissues while sensitizing tumors to ionizing radiation. Here we utilized a metabolomic approach to define molecular mechanisms underlying this radioprotective activity. CD47-deficient cells and cd47-null mice exhibited global advantages in preserving metabolite levels after irradiation. Metabolic pathways required for controlling oxidative stress and mediating DNA repair were enhanced. Some cellular energetics pathways differed basally in CD47-deficient cells, and the global declines in the glycolytic and tricarboxylic acid cycle metabolites characteristic of normal cell and tissue responses to irradiation were prevented in the absence of CD47. Thus, CD47 mediates signaling from the extracellular matrix that coordinately regulates basal metabolism and cytoprotective responses to radiation injury.

  10. Antacids: new perspectives in cytoprotection.

    PubMed

    Tarnawski, A; Hollander, D; Gergely, H

    1990-01-01

    There is increasing evidence that aluminum-containing antacids are able to protect the gastric mucosa against various ulcerogenic and necrotizing agents including 0.6 M HCl, 0.2 M NaOH, and absolute alcohol. Since gastric mucosal necrosis produced by alcohol is independent of luminal acid and cannot be reduced by H2-receptor antagonists, the protective action of antacids is accomplished by mechanism(s) other than acid-neutralizing ability. In addition, since acidified antacids can protect the gastric mucosa even better than an antacid with intact neutralizing capacity, it is clear that such action is independent of acid-neutralizing ability and therefore has all the features of cytoprotection. Whereas the cytoprotective action of antacids in experimental conditions is well established, the mechanisms of antacid-induced mucosal protection are not known. The clinical relevance of antacid-induced protection also requires further elucidation. Antacids have advantages over the H2 blockers in protecting the gastric mucosa against alcohol-induced necrosis and in preventing stress-induced ulcers in critically ill patients. Although more work is needed to clarify the mechanisms of cytoprotective action of antacids, the recent experimental findings gave a new life to and new potential clinical applications for antacids.

  11. Notch-Nrf2 Axis: Regulation of Nrf2 Gene Expression and Cytoprotection by Notch Signaling

    PubMed Central

    Skoko, John J.; Chartoumpekis, Dionysios V.; Kimura, Shoko; Slocum, Stephen L.; Noda, Kentaro; Palliyaguru, Dushani L.; Fujimuro, Masahiro; Boley, Patricia A.; Tanaka, Yugo; Shigemura, Norihisa; Biswal, Shyam; Yamamoto, Masayuki; Kensler, Thomas W.

    2014-01-01

    The Notch signaling pathway enables regulation and control of development, differentiation, and homeostasis through cell-cell communication. Our investigation shows that Notch signaling directly activates the Nrf2 stress adaptive response pathway through recruitment of the Notch intracellular domain (NICD) transcriptosome to a conserved Rbpjκ site in the promoter of Nrf2. Stimulation of Notch signaling through Notch ligand expression in cells and by overexpression of the NICD in RosaNICD/−::AlbCre mice in vivo induces expression of Nrf2 and its target genes. Continuous and transient NICD expression in the liver produces a Notch-dependent cytoprotective response through direct transcriptional activation of Nrf2 signaling to rescue mice from acute acetaminophen toxicity. This response can be reversed upon genetic disruption of Nrf2. Morphological studies showed that the characteristic phenotype of high-density intrahepatic bile ducts and enlarged liver in RosaNICD/−::AlbCre mice could be at least partially reversed after Nrf2 disruption. Furthermore, the liver and bile duct phenotypes could be recapitulated with constitutive activation of Nrf2 signaling in Keap1F/F::AlbCre mice. It appears that Notch-to-Nrf2 signaling is another important determinant in liver development and function and promotes cell-cell cytoprotective signaling responses. PMID:24298019

  12. New model of cytoprotection/adaptive cytoprotection in rats: endogenous small irritants, antiulcer agents and indomethacin.

    PubMed

    Sikirić, P; Seiwerth, S; Desković, S; Grabarević, Z; Marović, A; Rucman, R; Petek, M; Konjevoda, P; Jadrijević, S; Sosa, T; Perović, D; Aralica, G; Turković, B

    1999-01-01

    Adaptive cytoprotection in the stomach was originally defined by applying the exogenous irritants only. The contribution of endogenous irritants as inductors of initial lesions was not specially evaluated. No attempt was made to either focus antiulcer agent activity on adaptive cytoprotection, or split their 'cytoprotection' into complex adaptive cytoprotective activity and simple cytoprotective effects. Agents had so far not been applied simultaneously with the second challenge with ethanol (or irritant), when differences between cytoprotection and adaptive cytoprotection appear. Gastrojejunal anastomosis for 24 h in rats was introduced as new model for analyzing cytoprotection/adaptive cytoprotection. The contribution of the up-normal level of endogenous irritants and the endogenous small irritant-induced minor lesions during the adaptive cytoprotection were studied. The effect of late challenge with 96% ethanol in the presence of an up-normal level of endogenous irritants and endogenous small irritant-induced minor lesions was compared with results of classic studies of ethanol-induced gastric lesions in normal rats (1 ml/rat i.g.). Antiulcer agents or a prostaglandins-synthesis inhibitor, indomethacin, given once only in classic studies, were given at several points during injury induction: (i) surgery, (ii) mild ethanol, (iii) strong ethanol, (iv) strong ethanol applied after a suitable period following either mild ethanol or surgery). Their effects were compared in rats treated as follows: exogenous irritant studies (96% or 20% ethanol), exogenous/exogenous irritant studies (20% ethanol 1 h before 96% ethanol), endogenous irritant studies (gastrojejunal anastomosis for 24 h), and endogenous/exogenous irritant studies (gastrojejunal anastomosis for 24 h before 96% ethanol). Characteristic of the various irritants differed: the (preceding) small irritants (exogenous (i.e., mild ethanol in healthy intact rats) (exogenous irritant studies) vs. endogenous (e

  13. Genetic dissection of cardiac growth control pathways

    NASA Technical Reports Server (NTRS)

    MacLellan, W. R.; Schneider, M. D.

    2000-01-01

    Cardiac muscle cells exhibit two related but distinct modes of growth that are highly regulated during development and disease. Cardiac myocytes rapidly proliferate during fetal life but exit the cell cycle irreversibly soon after birth, following which the predominant form of growth shifts from hyperplastic to hypertrophic. Much research has focused on identifying the candidate mitogens, hypertrophic agonists, and signaling pathways that mediate these processes in isolated cells. What drives the proliferative growth of embryonic myocardium in vivo and the mechanisms by which adult cardiac myocytes hypertrophy in vivo are less clear. Efforts to answer these questions have benefited from rapid progress made in techniques to manipulate the murine genome. Complementary technologies for gain- and loss-of-function now permit a mutational analysis of these growth control pathways in vivo in the intact heart. These studies have confirmed the importance of suspected pathways, have implicated unexpected pathways as well, and have led to new paradigms for the control of cardiac growth.

  14. Genetic dissection of cardiac growth control pathways

    NASA Technical Reports Server (NTRS)

    MacLellan, W. R.; Schneider, M. D.

    2000-01-01

    Cardiac muscle cells exhibit two related but distinct modes of growth that are highly regulated during development and disease. Cardiac myocytes rapidly proliferate during fetal life but exit the cell cycle irreversibly soon after birth, following which the predominant form of growth shifts from hyperplastic to hypertrophic. Much research has focused on identifying the candidate mitogens, hypertrophic agonists, and signaling pathways that mediate these processes in isolated cells. What drives the proliferative growth of embryonic myocardium in vivo and the mechanisms by which adult cardiac myocytes hypertrophy in vivo are less clear. Efforts to answer these questions have benefited from rapid progress made in techniques to manipulate the murine genome. Complementary technologies for gain- and loss-of-function now permit a mutational analysis of these growth control pathways in vivo in the intact heart. These studies have confirmed the importance of suspected pathways, have implicated unexpected pathways as well, and have led to new paradigms for the control of cardiac growth.

  15. Cytoprotective, antihyperglycemic and phytochemical properties of Cocos nucifera (L.) inflorescence.

    PubMed

    Renjith, R S; Chikku, A M; Rajamohan, T

    2013-10-01

    To analyze the cytoprotective and antidiabetic activities as well as phytochemical composition of the immature inflorescence of Cocos nucifera belonging to the Arecaceae Family. The phytochemical screening of inflorescence was done to determine the major constituents present in Cocos nucifera inflorescence. The free radical scavenging potential of inflorescence extracts were evaluated using in vitro radical scavenging assay models. The phytochemical analyses on inflorescence showed the presence of phenolic compounds, flavonoids, resins and alkaloids. The macronutrient analyses, on the other hand, showed the presence of carbohydrate, proteins and fibers. Administration of the methanol extract of coconut inflorescence to the diabetic rats showed dose dependent reduction in hyperglycemia. The cytoprotective property of coconut inflorescence was evidenced from the acute toxicological evaluation. The levels of serum aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase were significantly decreased in the diabetic rats treated with inflorescence when compared with the diabetic control rats. The results obtained from the present study apparently proved the non-toxic nature and the cytoprotective and antihyperglycemic properties of coconut inflorescence. Copyright © 2013 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

  16. Synthesis of a series of caffeic acid phenethyl amide (CAPA) fluorinated derivatives: comparison of cytoprotective effects to caffeic acid phenethyl ester (CAPE).

    PubMed

    Yang, John; Marriner, Gwendolyn A; Wang, Xinyu; Bowman, Phillip D; Kerwin, Sean M; Stavchansky, Salomon

    2010-07-15

    A series of catechol ring-fluorinated derivatives of caffeic acid phenethyl amide (CAPA) were synthesized and screened for cytoprotective activity against H2O2 induced oxidative stress in human umbilical vein endothelial cells (HUVEC). CAPA and three fluorinated analogs were found to be significantly cytoprotective when compared to control, with no significant difference in cytoprotection between caffeic acid phenethyl ester (CAPE) and CAPA.

  17. An evolutionarily conserved pathway controls proteasome homeostasis

    PubMed Central

    Rousseau, Adrien; Bertolotti, Anne

    2016-01-01

    The proteasome is essential for the selective degradation of most cellular proteins but how cells maintain adequate amounts of proteasome is unclear. Here we found an evolutionarily conserved signalling pathway controlling proteasome homeostasis. Central to this pathway is TORC1 whose inhibition induced all known yeast 19S regulatory particle assembly-chaperones (RACs) as well as proteasome subunits. Downstream of TORC1 inhibition, the yeast mitogen-activated protein kinase, Mpk1, ensured that the supply of RACs and proteasome subunits increased under challenging conditions to maintain proteasomal degradation and cell viability. This adaptive pathway was evolutionarily conserved, with mTOR and Erk5 controlling the levels of the four mammalian RACs and proteasome abundance. Thus, the central growth and stress controllers, TORC1 and Mpk1/Erk5, endow cells with a rapid and vital adaptive response to adjust proteasome abundance to the rising needs. Enhancing this pathway may be a useful therapeutic approach for diseases resulting from impaired proteasomal degradation. PMID:27462806

  18. An evolutionarily conserved pathway controls proteasome homeostasis.

    PubMed

    Rousseau, Adrien; Bertolotti, Anne

    2016-08-11

    The proteasome is essential for the selective degradation of most cellular proteins, but how cells maintain adequate amounts of proteasome is unclear. Here we show that there is an evolutionarily conserved signalling pathway controlling proteasome homeostasis. Central to this pathway is TORC1, the inhibition of which induced all known yeast 19S regulatory particle assembly-chaperones (RACs), as well as proteasome subunits. Downstream of TORC1 inhibition, the yeast mitogen-activated protein kinase, Mpk1, acts to increase the supply of RACs and proteasome subunits under challenging conditions in order to maintain proteasomal degradation and cell viability. This adaptive pathway was evolutionarily conserved, with mTOR and ERK5 controlling the levels of the four mammalian RACs and proteasome abundance. Thus, the central growth and stress controllers, TORC1 and Mpk1/ERK5, endow cells with a rapid and vital adaptive response to adjust proteasome abundance in response to the rising needs of cells. Enhancing this pathway may be a useful therapeutic approach for diseases resulting from impaired proteasomal degradation.

  19. [Experiences with sodium selenite in treatment of acute and late adverse effects of radiochemotherapy of head-neck carcinomas. Cytoprotection Working Group in AK Supportive Measures in Oncology Within the scope of MASCC and DKG].

    PubMed

    Büntzel, J

    1999-10-15

    The principle of cytoprotection became a new supportive strategy in oncology during the last decade. Two principal ways of cytoprotection are well known in practice: the addition of external free thiols (for example amifostine) or the activation of internal detoxification-pathways (for example the activation of glutathione peroxidase) by administration of additional selenium. We report about our experiences in both fields: At first we could show the significant possibilities of cytoprotection to reduce the acute hematological and non hematological toxicities of a simultaneous radiochemotherapy (2 cycles Carboplatin, 2 Gy single dose, 60 Gy total dose) of head and neck cancer patients. After 1 year the survival of amifostine-protected patients was better compared to the control, the rate of severe late complications (xerostomia Grade 3/4) was decreased from 57% to 14%. At second we report about the usage of selenium in the treatment of paravasats (10 patients) and interstitial lymph edema (20 patients). In the acute intervention group 9/10 patients resolved from the paravasats without any necrosis. In the late intervention group 12/20 patients showed reduced edema. Nine of 15 patients with a supraglottic edema and subsequent dyspnoea resolved under treatment without any tracheostomy. On the base of these data we have planned a phase-I/II study to investigate the chances of both cytoprotectants alone and in combination in order to get the most favorable supportive regimen for our basic type of radiochemotherapy.

  20. Signalling Pathways Controlling Cellular Actin Organization.

    PubMed

    Steffen, Anika; Stradal, Theresia E B; Rottner, Klemens

    2017-01-01

    The actin cytoskeleton is essential for morphogenesis and virtually all types of cell shape changes. Reorganization is per definition driven by continuous disassembly and re-assembly of actin filaments, controlled by major, ubiquitously operating machines. These are specifically employed by the cell to tune its activities in accordance with respective environmental conditions or to satisfy specific needs.Here we sketch some fundamental signalling pathways established to contribute to the reorganization of specific actin structures at the plasma membrane. Rho-family GTPases are at the core of these pathways, and dissection of their precise contributions to actin reorganization in different cell types and tissues will thus continue to improve our understanding of these important signalling nodes. Furthermore, we will draw your attention to the emerging theme of actin reorganization on intracellular membranes, its functional relation to Rho-GTPase signalling, and its relevance for the exciting phenomenon autophagy.

  1. Signaling pathways controlling skeletal muscle mass.

    PubMed

    Egerman, Marc A; Glass, David J

    2014-01-01

    The molecular mechanisms underlying skeletal muscle maintenance involve interplay between multiple signaling pathways. Under normal physiological conditions, a network of interconnected signals serves to control and coordinate hypertrophic and atrophic messages, culminating in a delicate balance between muscle protein synthesis and proteolysis. Loss of skeletal muscle mass, termed "atrophy", is a diagnostic feature of cachexia seen in settings of cancer, heart disease, chronic obstructive pulmonary disease, kidney disease, and burns. Cachexia increases the likelihood of death from these already serious diseases. Recent studies have further defined the pathways leading to gain and loss of skeletal muscle as well as the signaling events that induce differentiation and post-injury regeneration, which are also essential for the maintenance of skeletal muscle mass. In this review, we summarize and discuss the relevant recent literature demonstrating these previously undiscovered mediators governing anabolism and catabolism of skeletal muscle.

  2. Signaling pathways controlling skeletal muscle mass

    PubMed Central

    Egerman, Marc A.

    2014-01-01

    The molecular mechanisms underlying skeletal muscle maintenance involve interplay between multiple signaling pathways. Under normal physiological conditions, a network of interconnected signals serves to control and coordinate hypertrophic and atrophic messages, culminating in a delicate balance between muscle protein synthesis and proteolysis. Loss of skeletal muscle mass, termed “atrophy”, is a diagnostic feature of cachexia seen in settings of cancer, heart disease, chronic obstructive pulmonary disease, kidney disease, and burns. Cachexia increases the likelihood of death from these already serious diseases. Recent studies have further defined the pathways leading to gain and loss of skeletal muscle as well as the signaling events that induce differentiation and post-injury regeneration, which are also essential for the maintenance of skeletal muscle mass. In this review, we summarize and discuss the relevant recent literature demonstrating these previously undiscovered mediators governing anabolism and catabolism of skeletal muscle. PMID:24237131

  3. The Role of Mcl-1 in S. aureus-Induced Cytoprotection of Infected Macrophages

    PubMed Central

    Koziel, Joanna; Kmiecik, Katarzyna; Chmiest, Daniela; Maresz, Katarzyna; Mizgalska, Danuta; Maciag-Gudowska, Agnieszka; Mydel, Piotr; Potempa, Jan

    2013-01-01

    As a facultative intracellular pathogen, Staphylococcus aureus invades macrophages and then promotes the cytoprotection of infected cells thus stabilizing safe niche for silent persistence. This process occurs through the upregulation of crucial antiapoptotic genes, in particular, myeloid cell leukemia-1 (MCL-1). Here, we investigated the underlying mechanism and signal transduction pathways leading to increased MCL-1 expression in infected macrophages. Live S. aureus not only stimulated de novo synthesis of Mcl-1, but also prolonged the stability of this antiapoptotic protein. Consistent with this, we proved a crucial role of Mcl-1 in S. aureus-induced cytoprotection, since silencing of MCL1 by siRNA profoundly reversed the cytoprotection of infected cells leading to apoptosis. Increased MCL1 expression in infected cells was associated with enhanced NFκB activation and subsequent IL-6 secretion, since the inhibition of both NFκB and IL-6 signalling pathways abrogated Mcl-1 induction and cytoprotection. Finally, we confirmed our observation in vivo in murine model of septic arthritis showing the association between the severity of arthritis and Mcl-1 expression. Therefore, we propose that S. aureus is hijacking the Mcl-1-dependent inhibition of apoptosis to prevent the elimination of infected host cells, thus allowing the intracellular persistence of the pathogen, its dissemination by infected macrophages, and the progression of staphylococci diseases. PMID:23431241

  4. Induction of cytoprotective autophagy in PC-12 cells by cadmium

    SciTech Connect

    Wang, Qiwen; Zhu, Jiaqiao; Zhang, Kangbao; Jiang, Chenyang; Wang, Yi; Yuan, Yan; Bian, Jianchun; Liu, Xuezhong; Gu, Jianhong; Liu, Zongping

    2013-08-16

    Highlights: •Cadmium can promote early upregulation of autophagy in PC-12 cells. •Autophagy precedes apoptosis in cadmium-treated PC-12 cells. •Cadmium-induced autophagy is cytoprotective in PC-12 cells. •Class III PI3K/beclin-1/Bcl-2 signaling pathway plays a positive role in cadmium-triggered autophagy. -- Abstract: Laboratory data have demonstrated that cadmium (Cd) may induce neuronal apoptosis. However, little is known about the role of autophagy in neurons. In this study, cell viability decreased in a dose- and time-dependent manner after treatment with Cd in PC-12 cells. As cells were exposed to Cd, the levels of LC3-II proteins became elevated, specific punctate distribution of endogenous LC3-II increased, and numerous autophagosomes appeared, which suggest that Cd induced a high level of autophagy. In the late stages of autophagy, an increase in the apoptosis ratio was observed. Likewise, pre-treatment with chloroquine (an autophagic inhibitor) and rapamycin (an autophagic inducer) resulted in an increased and decreased percentage of apoptosis in contrast to other Cd-treated groups, respectively. The results indicate that autophagy delayed apoptosis in Cd-treated PC-12 cells. Furthermore, co-treatment of cells with chloroquine reduced autophagy and cell activity. However, rapamycin had an opposite effect on autophagy and cell activity. Moreover, class III PI3 K/beclin-1/Bcl-2 signaling pathways served a function in Cd-induced autophagy. The findings suggest that Cd can induce cytoprotective autophagy by activating class III PI3 K/beclin-1/Bcl-2 signaling pathways. In sum, this study strongly suggests that autophagy may serve a positive function in the reduction of Cd-induced cytotoxicity.

  5. Revised Robert's cytoprotection and adaptive cytoprotection and stable gastric pentadecapeptide BPC 157. Possible significance and implications for novel mediator.

    PubMed

    Sikiric, Predrag; Seiwerth, Sven; Brcic, Luka; Sever, Marko; Klicek, Robert; Radic, Bozo; Drmic, Domagoj; Ilic, Spomenko; Kolenc, Danijela

    2010-01-01

    The significance of cytoprotection and adaptive cytoprotection and the peptides importance remained to be not completely determined. BPC 157 is an anti-ulcer peptidergic agent, proven in clinical trials to be both safe in inflammatory bowel disease (PL-10, PLD-116, PL 14736) and wound healing, and stable in human gastric juice, with no toxicity being reported. It has a prominent effect on alcohol- lesions (i.e., induced acutely and chronically) and non-steroidal anti-inflammatory drugs-lesions (while interestingly BPC 157 may both prevent and reverse adjuvant arthritis). To review the importance of BPC 157, this review focused on Robert's cytoprotection concept described in rat stomach, reviewing our evidence that may resolve whether the cytoprotection and adaptive cytoprotection is an uniform phenomenon or not; whether the phenomenon or phenomena are endogenous or not, depending on nature of the irritants (mild or strong); whether this may contribute to stomach mucosa defense either when threaten by various ulcerogens or afforded by various antiulcer agents; whether these phenomena are uniform in whole gastrointestinal tract or not; whether they are interrelated or not. Finally, the importance of the cytoprotection phenomena and cytoprotection activity for skin wound healing, and wound healing in general was challenged. Thereby, this review focused on BPC 157 role in cytoprotection and adaptative cytoprotection suggesting that it may be the essential endogenous mediator able to mediate both cytoprotective and adaptive cytoprotective response in stomach and the whole gastrointestinal tract with significant importance in wound healing as well.

  6. Molecular Pathways Controlling Autophagy in Pancreatic Cancer

    PubMed Central

    New, Maria; Van Acker, Tim; Long, Jaclyn S.; Sakamaki, Jun-ichi; Ryan, Kevin M.; Tooze, Sharon A.

    2017-01-01

    Pancreatic ductal adenocarcinoma (PDAC) is one of the few cancer types where the 5-year survival rate shows no improvement. Despite conflicting evidence, the majority of data points to an essential role for autophagy in PDAC growth and survival, in particular constitutively activated autophagy, can provide crucial fuel to PDAC tumor cells in their nutrient-deprived environment. Autophagy, which is required for cell homeostasis, can both suppress and promote tumorigenesis and tumor survival in a context-dependent manner. Protein by protein, the mystery of how PDAC abuses the cell’s homeostasis system for its malignant growth has recently begun to be unraveled. In this review, we focus on how autophagy is responsible for growth and development of PDAC tumors and where autophagy and the mechanisms controlling it fit into PDAC metabolism. Understanding the range of pathways controlling autophagy and their interplay in PDAC could open the way for new therapeutic avenues. PMID:28316954

  7. Molecular Pathways Controlling Autophagy in Pancreatic Cancer.

    PubMed

    New, Maria; Van Acker, Tim; Long, Jaclyn S; Sakamaki, Jun-Ichi; Ryan, Kevin M; Tooze, Sharon A

    2017-01-01

    Pancreatic ductal adenocarcinoma (PDAC) is one of the few cancer types where the 5-year survival rate shows no improvement. Despite conflicting evidence, the majority of data points to an essential role for autophagy in PDAC growth and survival, in particular constitutively activated autophagy, can provide crucial fuel to PDAC tumor cells in their nutrient-deprived environment. Autophagy, which is required for cell homeostasis, can both suppress and promote tumorigenesis and tumor survival in a context-dependent manner. Protein by protein, the mystery of how PDAC abuses the cell's homeostasis system for its malignant growth has recently begun to be unraveled. In this review, we focus on how autophagy is responsible for growth and development of PDAC tumors and where autophagy and the mechanisms controlling it fit into PDAC metabolism. Understanding the range of pathways controlling autophagy and their interplay in PDAC could open the way for new therapeutic avenues.

  8. Cytoprotective agents in experimental small bowel volvulus.

    PubMed

    Goldman, C D; Rudloff, M A; Ternberg, J L

    1987-03-01

    An accepted experimental model for midgut volvulus was used to produce small bowel strangulation obstruction of 48 hours duration in Sprague-Dawley rats. A 93% perioperative mortality rate resulted after release of the volvulus. Treatment with three cytoprotective agents at the time of volvulus release resulted in the following mortality rates: superoxide dismutase, 89%; ibuprofen, 50%; prostaglandin E1 (PGE1, 11%. The predominant cause of death in all treatment groups was bowel infarction, with a smaller number succumbing to either sepsis or circulatory collapse. Concomitant administration of ephedrine or indomethacin to suppress prostaglandin E1's splanchnic vasodilatory activity did not cause any increase in mortality. A trial of aspirin, to simulate PGE's antiplatelet actions, showed no reduction in mortality when compared with detorsion alone. Prostaglandin E1 and, to a lesser extent, ibuprofen, appear to have cytoprotective effects during reperfusion of bowel compromised by volvulus, independent of their influence on the mesenteric vasculature and thrombogenesis.

  9. Hydrogen Sulfide Is a Signaling Molecule and a Cytoprotectant

    PubMed Central

    Shibuya, Norihiro; Kimura, Yuka

    2012-01-01

    Abstract Significance: Accumulating evidence shows that hydrogen sulfide may function as a signaling molecule in processes such as neuromodulation in the brain and smooth muscle relaxation in the vascular system. It also has a cytoprotective effect, since it can protect neurons and cardiac muscle from oxidative stress and ischemia-reperfusion injury, respectively. Hydrogen sulfide can also modulate inflammation, insulin release, and angiogenesis. Recent Advances: The regulation of the activity of 3-mercaptopyruvate sulfur transferase (3MST) along with cysteine aminotransferase (CAT), one of the H2S producing pathways, has been demonstrated. The production of H2S by the pathway, which is regulated by Ca2+ and facilitated by thioredoxin and dihydrolipoic acid, is also involved in H2S signaling as well as cytoprotection. Sulfur hydration of proteins by H2S has been proposed to modulate protein functions. H2S-sensitive fluorescent probes, which enable us to measure the localization of H2S in real time, have been developed. Critical Issues: The basal concentrations of H2S have recently been measured and found to be much lower than those initially reported. However, the concentration of H2S reached in stimulated cells, as well as the regulation of H2S producing enzymes is not well understood. It has been proposed that some of the effects of H2S on the regulation of enzymes and receptors might be explained through the properties of sulfane sulfur (S0), another form of active sulfur. Future Directions: The determination of H2S concentrations in activated cells using new methods including H2S-sensitive fluorescent probes, as well as the investigation of the effects of H2S using specific inhibitors, may provide better understanding of the physiological function of this molecule. Clarifying mechanisms of H2S activity may also facilitate the development of new therapeutic compounds. Antioxid. Redox Signal. 17, 45–57. PMID:22229673

  10. Signaling Pathways that Control Cell Proliferation

    PubMed Central

    Duronio, Robert J.; Xiong, Yue

    2013-01-01

    Cells decide to proliferate or remain quiescent using signaling pathways that link information about the cellular environment to the G1 phase of the cell cycle. Progression through G1 phase is controlled by pRB proteins, which function to repress the activity of E2F transcription factors in cells exiting mitosis and in quiescent cells. Phosphorylation of pRB proteins by the G1 cyclin-dependent kinases (CDKs) releases E2F factors, promoting the transition to S phase. CDK activity is primarily regulated by the binding of CDK catalytic subunits to cyclin partners and CDK inhibitors. Consequently, both mitogenic and antiproliferative signals exert their effects on cell proliferation through the transcriptional regulation and ubiquitin-dependent degradation of cyclins and CDK inhibitors. PMID:23457258

  11. A thermosensory pathway that controls body temperature

    PubMed Central

    Nakamura, Kazuhiro; Morrison, Shaun F.

    2008-01-01

    Defending body temperature against environmental thermal challenges is one of the most fundamental homeostatic functions governed by the nervous system. Here we show a novel somatosensory pathway, which essentially constitutes the afferent arm of the thermoregulatory reflex triggered by cutaneous sensation of environmental temperature changes. Using rat in vivo electrophysiological and anatomical approaches, we revealed that lateral parabrachial neurons play a pivotal role in this pathway by glutamatergically transmitting cutaneous thermosensory signals received from spinal somatosensory neurons directly to the thermoregulatory command center, preoptic area. This feedforward pathway mediates not only sympathetic and shivering thermogenic responses but also metabolic and cardiac responses to skin cooling challenges. Notably, this ‘thermoregulatory afferent’ pathway exists in parallel with the spinothalamocortical somatosensory pathway mediating temperature perception. These findings make an important contribution to our understanding of both the somatosensory system and thermal homeostasis—two mechanisms fundamental to the nervous system and to our survival. PMID:18084288

  12. A thermosensory pathway that controls body temperature.

    PubMed

    Nakamura, Kazuhiro; Morrison, Shaun F

    2008-01-01

    Defending body temperature against environmental thermal challenges is one of the most fundamental homeostatic functions that are governed by the nervous system. Here we describe a somatosensory pathway that essentially constitutes the afferent arm of the thermoregulatory reflex that is triggered by cutaneous sensation of environmental temperature changes. Using in vivo electrophysiological and anatomical approaches in the rat, we found that lateral parabrachial neurons are pivotal in this pathway by glutamatergically transmitting cutaneous thermosensory signals received from spinal somatosensory neurons directly to the thermoregulatory command center, the preoptic area. This feedforward pathway mediates not only sympathetic and shivering thermogenic responses but also metabolic and cardiac responses to skin cooling challenges. Notably, this 'thermoregulatory afferent' pathway exists in parallel with the spinothalamocortical somatosensory pathway that mediates temperature perception. These findings make an important contribution to our understanding of both the somatosensory system and thermal homeostasis -- two mechanisms that are fundamental to the nervous system and to our survival.

  13. Clinical Trials For Cytoprotection In Stroke

    PubMed Central

    Labiche, Lise A.; Grotta, James C.

    2004-01-01

    Summary: To date, many cytoprotective drugs have reached the stage of pivotal phase 3 efficacy trials in acute stroke patients. (Table 1) Unfortunately, throughout the neuroprotective literature, the phrase “failure to demonstrate efficacy” prevails as a common thread among the many neutral or negative trials, despite the largely encouraging results encountered in preclinical studies. The reasons for this discrepancy are multiple, and have been discussed by Dr. Zivin in his review. Many of the recent trials have addressed deficiencies of the previous ones with more rigorous trial design, including more specific patient selection criteria (ensure homogeneity of stroke location and severity), stratified randomization algorithms (time-to-treat), narrowed therapeutic time-window and pharmacokinetic monitoring. Current trials have also incorporated biologic surrogate markers of toxicity and outcome such as drug levels and neuroimaging. Lastly, multi-modal therapies and coupled cytoprotection/reperfusion strategies are being investigated to optimize tissue salvage. This review will focus on individual therapeutic strategies and we will emphasize what we have learned from these trials both in terms of trial design and the biologic effect (or lack thereof) of these agents. PMID:15717007

  14. Pathway Controlled Penetration (PcP)

    SciTech Connect

    Knight, Earl E.; Rougier, Esteban; Zubelewicz, Aleksander

    2012-08-29

    The technical approach employs advanced computational simulation tools to demonstrate how current assets can destroy RWK-RFI-12-0001's HDBT, a tunnel complex with two portals built into the base of a granite mountain. The granite over layer is assumed to be 60 meters thick over both portals and 80 meters over the facility's mission space. Key S&T is the completed development of a highly innovative viscoplastic fracture material model, 3D parallel gas-fracture capabilities into FDEM, and a stochastic handling of the material properties. Phase I - Develop and validate code simulation tools: (1) develop, incorporate and validate AZ-Frac material model for granite; and (2) Develop and incorporate gas-driven-fracture modeling into LANL's FDEM MUNROU code; (3) Develop and incorporate stochastic features into FDEM modeling. Phase II - Conduct PcP analysis on above HDBT: (1) Acquire HDBT design data, develop simulation model; and (2) Evaluate and select most promising defeat alternative. Phase III - Deliver code, train Service target analysts, and conduct simulations against real world HDBTs. PcP uses advanced computer simulations to enhance HDBT functional defeat efforts. Newly developed material models that account for fractural energy coupled with the finite discrete element methodology (FDEM) will provide targeting packages that will create penetration avenues for current or future lethality options. This novel computational approach requires full 3D geologic and structure characterization as well as significant high performance computing capabilities. The goal is to distinctively alter the targeting paradigm by leveraging critical DoD assets along with insitu geologic strata. In other words, assets will utilize underground rock structure to their benefit by creating rubbilization zones that will allow pathway controlled penetration.

  15. Expression of taurine transporter is regulated through the TonE (tonicity-responsive element)/TonEBP (TonE-binding protein) pathway and contributes to cytoprotection in HepG2 cells.

    PubMed

    Ito, Takashi; Fujio, Yasushi; Hirata, Mayo; Takatani, Tomoka; Matsuda, Takahisa; Muraoka, Satoko; Takahashi, Kyoko; Azuma, Junichi

    2004-08-15

    In hypertonic environment, taurine accumulates in cells via activation of TauT (taurine transporter) as an adaptive regulation. Recent studies revealed that TonE (tonicity-responsive element)/TonEBP (TonE-binding protein) pathway regulated the expression of various molecules which protect cells against hypertonic stress. In the present study, we investigated the osmoregulatory mechanisms of TauT expression. TauT was up-regulated at both functional and transcriptional levels in HepG2 under hypertonic condition. The TonE site was identified in the promoter region of TauT gene. Reporter gene assay revealed that promoter activity was increased under hypertonic conditions, whereas deletion or mutation of TonE sequence abolished the induction of the promoter activity in response to hypertonicity. By using the reporter gene plasmids containing a TonE site of TauT promoter (p2xTonE-Luc), it was demonstrated that a TonE site was sufficient for the hypertonicity-mediated activation of TauT promoter. Importantly, co-transfection of TauT promoter gene plasmid with wild-type TonEBP expression vector enhanced promoter activity under isotonic conditions, whereas dominant-negative TonEBP abrogated the TauT promoter activity induced by hypertonicity. Finally, treatment with taurine prevented HepG2 cells from cell death induced by hypertonic medium. These findings suggested that induction of TauT by hypertonicity is mediated by the activation of the TonE/TonEBP pathway and confers resistance to hypertonic stress.

  16. Expression of taurine transporter is regulated through the TonE (tonicity-responsive element)/TonEBP (TonE-binding protein) pathway and contributes to cytoprotection in HepG2 cells

    PubMed Central

    2004-01-01

    In hypertonic environment, taurine accumulates in cells via activation of TauT (taurine transporter) as an adaptive regulation. Recent studies revealed that TonE (tonicity-responsive element)/TonEBP (TonE-binding protein) pathway regulated the expression of various molecules which protect cells against hypertonic stress. In the present study, we investigated the osmoregulatory mechanisms of TauT expression. TauT was up-regulated at both functional and transcriptional levels in HepG2 under hypertonic condition. The TonE site was identified in the promoter region of TauT gene. Reporter gene assay revealed that promoter activity was increased under hypertonic conditions, whereas deletion or mutation of TonE sequence abolished the induction of the promoter activity in response to hypertonicity. By using the reporter gene plasmids containing a TonE site of TauT promoter (p2xTonE-Luc), it was demonstrated that a TonE site was sufficient for the hypertonicity-mediated activation of TauT promoter. Importantly, co-transfection of TauT promoter gene plasmid with wild-type TonEBP expression vector enhanced promoter activity under isotonic conditions, whereas dominant-negative TonEBP abrogated the TauT promoter activity induced by hypertonicity. Finally, treatment with taurine prevented HepG2 cells from cell death induced by hypertonic medium. These findings suggested that induction of TauT by hypertonicity is mediated by the activation of the TonE/TonEBP pathway and confers resistance to hypertonic stress. PMID:15142033

  17. Effects of polyphenol-rich plant products from grape or hop as feed supplements on the expression of inflammatory, antioxidative, cytoprotective and endoplasmic reticulum stress-related genes and the antioxidative status in the liver of piglets.

    PubMed

    Gessner, D K; Bonarius, M; Most, E; Fiesel, A; Eder, K

    2016-08-26

    Recent studies have shown that supplementation of plant products rich in polyphenols exerts anti-inflammatory effects in the small intestine and improves feed conversion in piglets. This study aimed to investigate whether dietary polyphenols have also anti-inflammatory and cytoprotective effects in the liver of piglets. For this end, relative mRNA concentrations of eight genes involved in proinflammatory pathways, eight genes involved in the antioxidative and cytoprotective system, six genes of phase I and phase II metabolism and 15 genes of the unfolded protein response (triggered by stress of the endoplasmic reticulum) in the liver of pigs fed diets supplemented with either 1% of grape seed and grape marc meal extract (GME) or 1% spent hops (SH) as sources of polyphenols were determined. Relative mRNA concentrations of almost all these genes, with few exceptions, in the liver of pigs supplemented with GME or SH did not differ from those in the liver of control piglets. Gene expression data were validated by consideration of concentrations of some selected proteins of these pathways which also did not differ between piglets supplemented with GME or SH and control piglets. Moreover, concentrations of thiobarbituric acid-reactive substances and tocopherols as well as the total antioxidant capacity in liver and plasma did not differ between pigs supplemented with either GME or SH and control piglets. Overall, this study shows that supplementation of GME or SH as sources of polyphenols does not influence hepatic pathways linked to inflammation, the antioxidant and cytoprotective system, stress of the endoplasmic reticulum and the xenobiotic system in healthy piglets. Journal of Animal Physiology and Animal Nutrition © 2016 Blackwell Verlag GmbH.

  18. Hsp27 binding to the 3′UTR of bim mRNA prevents neuronal death during oxidative stress–induced injury: a novel cytoprotective mechanism

    PubMed Central

    Dávila, David; Jiménez-Mateos, Eva M.; Mooney, Claire M.; Velasco, Guillermo; Henshall, David C.; Prehn, Jochen H. M.

    2014-01-01

    Neurons face a changeable microenvironment and therefore need mechanisms that allow rapid switch on/off of their cytoprotective and apoptosis-inducing signaling pathways. Cellular mechanisms that control apoptosis activation include the regulation of pro/antiapoptotic mRNAs through their 3′-untranslated region (UTR). This region holds binding elements for RNA-binding proteins, which can control mRNA translation. Here we demonstrate that heat shock protein 27 (Hsp27) prevents oxidative stress–induced cell death in cerebellar granule neurons by specific regulation of the mRNA for the proapoptotic BH3-only protein, Bim. Hsp27 depletion induced by oxidative stress using hydrogen peroxide (H2O2) correlated with bim gene activation and subsequent neuronal death, whereas enhanced Hsp27 expression prevented these. This effect could not be explained by proteasomal degradation of Bim or bim promoter inhibition; however, it was associated with a specific increase in the levels of bim mRNA and with its binding to Hsp27. Finally, we determined that enhanced Hsp27 expression in neurons exposed to H2O2 or glutamate prevented the translation of a reporter plasmid where bim-3′UTR mRNA sequence was cloned downstream of a luciferase gene. These results suggest that repression of bim mRNA translation through binding to the 3′UTR constitutes a novel cytoprotective mechanism of Hsp27 during stress in neurons. PMID:25187648

  19. Hsp27 binding to the 3'UTR of bim mRNA prevents neuronal death during oxidative stress-induced injury: a novel cytoprotective mechanism.

    PubMed

    Dávila, David; Jiménez-Mateos, Eva M; Mooney, Claire M; Velasco, Guillermo; Henshall, David C; Prehn, Jochen H M

    2014-11-01

    Neurons face a changeable microenvironment and therefore need mechanisms that allow rapid switch on/off of their cytoprotective and apoptosis-inducing signaling pathways. Cellular mechanisms that control apoptosis activation include the regulation of pro/antiapoptotic mRNAs through their 3'-untranslated region (UTR). This region holds binding elements for RNA-binding proteins, which can control mRNA translation. Here we demonstrate that heat shock protein 27 (Hsp27) prevents oxidative stress-induced cell death in cerebellar granule neurons by specific regulation of the mRNA for the proapoptotic BH3-only protein, Bim. Hsp27 depletion induced by oxidative stress using hydrogen peroxide (H2O2) correlated with bim gene activation and subsequent neuronal death, whereas enhanced Hsp27 expression prevented these. This effect could not be explained by proteasomal degradation of Bim or bim promoter inhibition; however, it was associated with a specific increase in the levels of bim mRNA and with its binding to Hsp27. Finally, we determined that enhanced Hsp27 expression in neurons exposed to H2O2 or glutamate prevented the translation of a reporter plasmid where bim-3'UTR mRNA sequence was cloned downstream of a luciferase gene. These results suggest that repression of bim mRNA translation through binding to the 3'UTR constitutes a novel cytoprotective mechanism of Hsp27 during stress in neurons.

  20. Cytoprotective effects of disodium cromoglycate on rat stomach mucosa.

    PubMed Central

    Goossens, J.; Van Reempts, J.; Van Wauwe, J. P.

    1987-01-01

    The cytoprotective effects of the anti-asthmatic drug, disodium cromoglycate (DSCG), on gastric mucosal necrosis induced by ethanol in rats were studied. Subcutaneous, but not oral, DSCG prevented the formation of gastric lesions and this effect was dose-dependent between 1.25 and 40 mg kg-1, with an ED50 value of 6.8 mg kg-1. Maximal cytoprotection occurred 15-30 min after DSCG treatment. Histological examination revealed that DSCG effectively protected the gastric mucosa against ethanol-induced vascular congestion, haemorrhage, epithelial desquamation and mucosal oedema. Enhanced production of endogenous prostaglandins, which are known cytoprotective compounds, could not explain the mucosal protection. At a dose of 40 mg kg-1, DSCG did not change prostaglandin E2 or 6-keto-prostaglandin F1 alpha concentrations in gastric mucosal tissue, although its cytoprotective activity was partially inhibited by prior treatment of the animals with indomethacin. Images Figure 2 PMID:3109535

  1. Novel PI3K/Akt Inhibitors Screened by the Cytoprotective Function of Human Immunodeficiency Virus Type 1 Tat

    PubMed Central

    Kim, Dong-Hyun; Kim, Baek

    2011-01-01

    The PI3K/Akt pathway regulates various stress-related cellular responses such as cell survival, cell proliferation, metabolism and protein synthesis. Many cancer cell types display the activation of this pathway, and compounds inhibiting this cell survival pathway have been extensively evaluated as anti-cancer agents. In addition to cancers, several human viruses, such as HTLV, HPV, HCV and HIV-1, also modulate this pathway, presumably in order to extend the life span of the infected target cells for productive viral replication. The expression of HIV-1 Tat protein exhibited the cytoprotective effect in macrophages and a human microglial cell line by inhibiting the negative regulator of this pathway, PTEN. This cytoprotective effect of HIV-1 appears to contribute to the long-term survival and persistent HIV-1 production in human macrophage reservoirs. In this study we exploited the PI3K/Akt dependent cytoprotective effect of Tat-expressing CHME5 cells. We screened a collection of compounds known to modulate inflammation, and identified three novel compounds: Lancemaside A, Compound K and Arctigenin that abolished the cytoprotective phenotype of Tat-expressing CHME5 cells. All three compounds antagonized the kinase activity of Akt. Further detailed signaling studies revealed that each of these three compounds targeted different steps of the PI3K/Akt pathway. Arctigenin regulates the upstream PI3K enzyme from converting PIP2 to PIP3. Lancemaside A1 inhibited the movement of Akt to the plasma membrane, a critical step for Akt activation. Compound K inhibited Akt phosphorylation. This study supports that Tat-expressing CHME5 cells are an effective model system for screening novel PI3K/Akt inhibitors. PMID:21765914

  2. Erythrocytosis: the HIF pathway in control.

    PubMed

    Franke, Kristin; Gassmann, Max; Wielockx, Ben

    2013-08-15

    Organisms living under aerobic conditions need oxygen for the metabolic conversion of nutrition into energy. With the appearance of increasingly complex animals, a specialized transport system (erythrocytes) arose during evolution to provide oxygen to virtually every single cell in the body. Moreover, in case of low environmental partial pressure of oxygen, the number of erythrocytes automatically increases to preserve sustained oxygen delivery. This process relies predominantly on the cytokine erythropoietin (Epo) and its transcription factor hypoxia inducible factor (HIF), whereas the von Hippel-Lindau (VHL) ubiquitin ligase as well as the oxygen-sensitive prolyl hydroxylases (PHDs) represent essential regulators of this oxygen-sensing system. Deregulation of particular members of this pathway (eg, PHD2, HIF2α, VHL) lead to disorders in blood homeostasis as a result of insufficient (anemia) or excessive (erythrocytosis) red blood cell production.

  3. Constituents from the stem barks of Canarium bengalense with cytoprotective activity against hydrogen peroxide-induced hepatotoxicity.

    PubMed

    Le, Hoang Thi; Ha, Do Thi; Minh, Chau Thi Anh; Kim, Tae Hoon; Van Kiem, Phan; Thuan, Nguyen Duy; Na, Minkyun

    2012-01-01

    Phytochemical investigation of the stem barks of Canarium bengalense (Burseraceace) resulted in the isolation of a new flavone glycoside (5) together with six known compounds (1-4, 6, and 7). The chemical structure of the new compound was elucidated as 3'-hydroxy-7,4'-dimethoxyflavone-5-O-α-L-arabinofuranosyl-(1→6)-β-D-glucopyranoside by means of 1D and 2D NMR ((1)H-(1)H COSY, HMQC, and HMBC) and MS analyses. To evaluate the in vitro cytoprotective effect, the isolates (1-7) were tested against hydrogen peroxide (H(2)O(2))-induced damage in primary cultured hepatocytes. The viability of hepatocytes was increased by treatment with each compound, except compound 1. Compounds 3, 4, and 7 exerted cytoprotective effects comparable to curcumin, the positive control. Our results suggest that the cytoprotective constituents of C. bengalense may contribute to its traditional use in the treatment of tumor and liver damage.

  4. Testing the gonadal regression-cytoprotection hypothesis.

    PubMed

    Crawford, B A; Spaliviero, J A; Simpson, J M; Handelsman, D J

    1998-11-15

    Germinal damage is an almost universal accompaniment of cancer treatment as the result of bystander damage to the testis from cytotoxic drugs and/or irradiation. Cancer treatment for the most common cancers of the reproductive age group in men has improved such that most are now treated with curative intent, and many others are treated with likelihood of prolonged survival, so that the preservation of fertility is an important component of posttreatment quality of life. This has led to the consideration of developing adjuvant treatments that may reduce the gonadal toxicity of cancer therapy. One dominant hypothesis has been based on the supposition that the immature testis was resistant to cytotoxin damage. Hence, if hormonal treatment were able to cause spermatogenic regression to an immature state via an effective withdrawal of gonadotrophin secretion, the testis might be maintained temporarily in a protected state during cytotoxin exposure. However, clinical studies have been disappointing but have also been unable to test the hypothesis definitively thus far, due to the inability to completely suppress gonadotrophin secretion. Similarly, experimental models have also given conflicting results and, at best, a modest cytoprotection. To definitively test this hypothesis experimentally, we used the fact that the functionally hpg mouse has complete gonadotrophin deficiency but can undergo the induction of full spermatogenesis by testosterone. Thus, if complete gonadotrophin deficiency were an advantage during cytotoxin exposure, then the hpg mouse should exhibit some degree of germinal protection against cytotoxin-induced damage. We therefore administered three different cytotoxins (200 mg/kg procarbazine, 9 mg/kg doxorubicin, 8 Gy of X irradiation) to produce a range of severity in testicular damage and mechanism of action to either phenotypically normal or hpg mice. Testis weight and homogenization-resistant spermatid numbers were measured to evaluate the

  5. Preparation and performance evaluation of plain proliposomal systems for cytoprotection.

    PubMed

    Katare, O P; Vyas, S P; Dixit, V K

    1991-01-01

    Plain liposomal systems composed of soyabean lecithin, cholesterol and stearylamine were formulated using various approaches. The prepared products were characterized and evaluated for their cytoprotective performance against the necrotizing NSAID's (i.e. aspirin and phenylbutazone). Liposomes derived from proliposomes (effervescent granules based) demonstrated the best cytoprotective activity and physical and stability characteristics. This system was shown to be superior. An increased availability of regular and small sized liposome born phospholipids to the damaged mucosal systems accounted for its better and enhanced performance.

  6. Gastric cytoprotection and honey intake in albino rats.

    PubMed

    Alagwu, E A; Nneli, R O; Egwurugwu, J N; Osim, E E

    2011-11-23

    Beneficial effect of honey has been widely reported particularly on wound healings, gastrointestinal disorders and as antibacterial agent. However, there is paucity of report on its cytoprotective effect on the gastric mucosa despite its common usage worldwide including Nigeria. This study was therefore carried out to evaluate the effect of this widely consumed substance on gastric mucosa using animal model and also to explore possible mechanism of its action on the gastric mucosa .Twenty male adult albino rats of Wistar strain, weighing between 210-220g were used in the experiment. They were randomly assigned into two groups, the control group and the honey-fed (test) group, each containing ten rats. The Control group was fed on normal rat feed and water while the test group was fed on normal rat feed with honey added to its drinking water (1ml of honey for every initial 10ml of water for each rat daily) for twenty two weeks. After twenty two weeks the rats were weighed after being starved overnight. They were anaesthetized with urethane (0.6ml/100g body weight). Gastric ulceration was induced using 1.5ml acid-alcohol prepared from equivolume of 0.1NHCl and 70% methanol introduced into the stomach via a portex cannula tied and left in place following an incision made on the antral-pyloric junction of the stomach. The acid-alcohol was allowed to stay for 1hr. After 1hr, laparatomy was performed and the stomach isolated, cut open along the greater curvature, rinsed with normal saline and fastened in place with pins on a dissecting board for ulcer examination and scores. The result obtained showed mean ulcer scores of 14.5+/-0.70 for the control group and 1.6+/-0.11 for the test group. The result showed that honey significantly reduced ulcer scores as well as caused scanty haemorrhage in the test group compared with increased ulcer scores and multiple haemorrhage in the control group. It is therefore concluded that honey intake offered cytoprotection on the gastric

  7. Antioxidant and cytoprotective responses to redox stress.

    PubMed

    Mathers, Joanne; Fraser, Jennifer A; McMahon, Michael; Saunders, Robert D C; Hayes, John D; McLellan, Lesley I

    2004-01-01

    Aerobic cells produce reactive oxygen species as a consequence of normal cellular metabolism, and an array of antioxidant systems are in place to maintain the redox balance. When the redox equilibrium of the cell is upset by pro-oxidant environmental stimuli, adaptive responses to the redox stress take place, which can result in up-regulation of antioxidant proteins and detoxification enzymes. Over the past few years, it has become apparent that members of the CNC (cap 'n' collar)-basic leucine zipper family of transcription factors are principal mediators of defensive responses to redox stress. In mammals, the CNC family members nuclear factor-erythroid 2 p45-related factors 1 and 2 (Nrf1 and Nrf2) have been shown to be involved in the transcriptional up-regulation of cytoprotective genes including those encoding glutamate cysteine ligase, NAD(P)H:quinone oxidoreductase, glutathione S-transferases and aldo-keto reductases. An evolutionarily conserved system exists in Caenorhabditis elegans, and it is possible that Drosophila melanogaster may also utilize CNC transcription factors to induce antioxidant genes in response to pro-oxidant chemicals. The advent of microarray and proteomic technologies has advanced our understanding of the gene batteries regulated by oxidative insult, but has highlighted the complexity of gene regulation by environmental factors. This review focuses on the antioxidant response to environmental stress, and the impact that microarrays and proteomics have made in this field.

  8. Targeting Transmission Pathways for Emerging Zoonotic Disease Surveillance and Control

    PubMed Central

    Loh, Elizabeth H.; Zambrana-Torrelio, Carlos; Olival, Kevin J.; Bogich, Tiffany L.; Johnson, Christine K.; Mazet, Jonna A. K.; Karesh, William

    2015-01-01

    Abstract We used literature searches and a database of all reported emerging infectious diseases (EIDs) to analyze the most important transmission pathways (e.g., vector-borne, aerosol droplet transmitted) for emerging zoonoses. Our results suggest that at the broad scale, the likelihood of transmission occurring through any one pathway is approximately equal. However, the major transmission pathways for zoonoses differ widely according to the specific underlying drivers of EID events (e.g., land-use change, agricultural intensification). These results can be used to develop better targeting of surveillance for, and more effective control of newly emerged zoonoses in regions under different underlying pressures that drive disease emergence. PMID:26186515

  9. Control and regulation of pathways via negative feedback

    PubMed Central

    2017-01-01

    The biochemical networks found in living organisms include a huge variety of control mechanisms at multiple levels of organization. While the mechanistic and molecular details of many of these control mechanisms are understood, their exact role in driving cellular behaviour is not. For example, yeast glycolysis has been studied for almost 80 years but it is only recently that we have come to understand the systemic role of the multitude of feedback and feed-forward controls that exist in this pathway. In this article, control theory is discussed as an approach to dissect the control logic of complex pathways. One of the key issues is distinguishing between the terms control and regulation and how these concepts are applied to regulated enzymes such as phosphofructokinase. In doing so, one of the paradoxes in metabolic regulation can be resolved where enzymes such as phosphofructokinase have little control but, nevertheless, possess significant regulatory influence. PMID:28202588

  10. Autophagy mediates epithelial cytoprotection in eosinophilic oesophagitis.

    PubMed

    Whelan, Kelly A; Merves, Jamie F; Giroux, Veronique; Tanaka, Koji; Guo, Andy; Chandramouleeswaran, Prasanna M; Benitez, Alain J; Dods, Kara; Que, Jianwen; Masterson, Joanne C; Fernando, Shahan D; Godwin, Bridget C; Klein-Szanto, Andres J; Chikwava, Kudakwashe; Ruchelli, Eduardo D; Hamilton, Kathryn E; Muir, Amanda B; Wang, Mei-Lun; Furuta, Glenn T; Falk, Gary W; Spergel, Jonathan M; Nakagawa, Hiroshi

    2017-07-01

    The influence of eosinophilic oesophagitis (EoE)-associated inflammation upon oesophageal epithelial biology remains poorly understood. We investigated the functional role of autophagy in oesophageal epithelial cells (keratinocytes) exposed to the inflammatory EoE milieu. Functional consequences of genetic or pharmacological autophagy inhibition were assessed in endoscopic oesophageal biopsies, human oesophageal keratinocytes, single cell-derived ex vivo murine oesophageal organoids as well as a murine model recapitulating EoE-like inflammation and basal cell hyperplasia. Gene expression, morphological and functional characterisation of autophagy and oxidative stress were performed by transmission electron microscopy, immunostaining, immunoblotting, live cell imaging and flow cytometry. EoE-relevant inflammatory conditions promoted autophagy and basal cell hyperplasia in three independent murine EoE models and oesophageal organoids. Inhibition of autophagic flux via chloroquine treatment augmented basal cell hyperplasia in these model systems. Oesophageal keratinocytes stimulated with EoE-relevant cytokines, including tumour necrosis factor-α and interleukin-13 exhibited activation of autophagic flux in a reactive oxygen species-dependent manner. Autophagy inhibition via chloroquine treatment or depletion of Beclin-1 or ATG-7, augmented oxidative stress induced by EoE-relevant stimuli in murine EoE, oesophageal organoids and human oesophageal keratinocytes. Oesophageal epithelia of paediatric EoE patients with active inflammation displayed increased autophagic vesicle content compared with normal and EoE remission subjects. Functional flow cytometric analysis revealed autophagic flux in human oesophageal biopsies. Our findings reveal for the first time that autophagy may function as a cytoprotective mechanism to maintain epithelial redox balance and homeostasis under EoE inflammation-associated stress, providing mechanistic insights into the role of autophagy in

  11. Version control of pathway models using XML patches

    PubMed Central

    Saffrey, Peter; Orton, Richard

    2009-01-01

    Background Computational modelling has become an important tool in understanding biological systems such as signalling pathways. With an increase in size complexity of models comes a need for techniques to manage model versions and their relationship to one another. Model version control for pathway models shares some of the features of software version control but has a number of differences that warrant a specific solution. Results We present a model version control method, along with a prototype implementation, based on XML patches. We show its application to the EGF/RAS/RAF pathway. Conclusion Our method allows quick and convenient storage of a wide range of model variations and enables a thorough explanation of these variations. Trying to produce these results without such methods results in slow and cumbersome development that is prone to frustration and human error. PMID:19292901

  12. Celastrols as inducers of the heat shock response and cytoprotection.

    PubMed

    Westerheide, Sandy D; Bosman, Joshua D; Mbadugha, Bessie N A; Kawahara, Tiara L A; Matsumoto, Gen; Kim, Soojin; Gu, Wenxin; Devlin, John P; Silverman, Richard B; Morimoto, Richard I

    2004-12-31

    Alterations in protein folding and the regulation of conformational states have become increasingly important to the functionality of key molecules in signaling, cell growth, and cell death. Molecular chaperones, because of their properties in protein quality control, afford conformational flexibility to proteins and serve to integrate stress-signaling events that influence aging and a range of diseases including cancer, cystic fibrosis, amyloidoses, and neurodegenerative diseases. We describe here characteristics of celastrol, a quinone methide triterpene and an active component from Chinese herbal medicine identified in a screen of bioactive small molecules that activates the human heat shock response. From a structure/function examination, the celastrol structure is remarkably specific and activates heat shock transcription factor 1 (HSF1) with kinetics similar to those of heat stress, as determined by the induction of HSF1 DNA binding, hyperphosphorylation of HSF1, and expression of chaperone genes. Celastrol can activate heat shock gene transcription synergistically with other stresses and exhibits cytoprotection against subsequent exposures to other forms of lethal cell stress. These results suggest that celastrols exhibit promise as a new class of pharmacologically active regulators of the heat shock response.

  13. Searching for pathways involving dressed states in optimal control theory.

    PubMed

    von den Hoff, Philipp; Kowalewski, Markus; de Vivie-Riedle, Regina

    2011-01-01

    Selective population of dressed states has been proposed as an alternative control pathway in molecular reaction dynamics [Wollenhaupt et al., J. Photochem. Photobiol. A: Chem., 2006, 180, 248]. In this article we investigate if, and under which conditions, this strong field pathway is included in the search space of optimal control theory. For our calculations we used the proposed example of the potassium dimer, in which the different target states can be reached via dressed states by resonant transition. Especially, we investigate whether the optimization algorithm is able to find the route involving the dressed states although the target state lies out of resonance in the bare state picture.

  14. Neurotropic arboviruses induce interferon regulatory factor 3-mediated neuronal responses that are cytoprotective, interferon independent, and inhibited by Western equine encephalitis virus capsid.

    PubMed

    Peltier, Daniel C; Lazear, Helen M; Farmer, Jocelyn R; Diamond, Michael S; Miller, David J

    2013-02-01

    Cell-intrinsic innate immune responses mediated by the transcription factor interferon regulatory factor 3 (IRF-3) are often vital for early pathogen control, and effective responses in neurons may be crucial to prevent the irreversible loss of these critical central nervous system cells after infection with neurotropic pathogens. To investigate this hypothesis, we used targeted molecular and genetic approaches with cultured neurons to study cell-intrinsic host defense pathways primarily using the neurotropic alphavirus western equine encephalitis virus (WEEV). We found that WEEV activated IRF-3-mediated neuronal innate immune pathways in a replication-dependent manner, and abrogation of IRF-3 function enhanced virus-mediated injury by WEEV and the unrelated flavivirus St. Louis encephalitis virus. Furthermore, IRF-3-dependent neuronal protection from virus-mediated cytopathology occurred independently of autocrine or paracrine type I interferon activity. Despite being partially controlled by IRF-3-dependent signals, WEEV also disrupted antiviral responses by inhibiting pattern recognition receptor pathways. This antagonist activity was mapped to the WEEV capsid gene, which disrupted signal transduction downstream of IRF-3 activation and was independent of capsid-mediated inhibition of host macromolecular synthesis. Overall, these results indicate that innate immune pathways have important cytoprotective activity in neurons and contribute to limiting injury associated with infection by neurotropic arboviruses.

  15. A controlled vocabulary for pathway entities and events.

    PubMed

    Jupe, Steve; Jassal, Bijay; Williams, Mark; Wu, Guanming

    2014-01-01

    Entities involved in pathways and the events they participate in require descriptive and unambiguous names that are often not available in the literature or elsewhere. Reactome is a manually curated open-source resource of human pathways. It is accessible via a website, available as downloads in standard reusable formats and via Representational State Transfer (REST)-ful and Simple Object Access Protocol (SOAP) application programming interfaces (APIs). We have devised a controlled vocabulary (CV) that creates concise, unambiguous and unique names for reactions (pathway events) and all the molecular entities they involve. The CV could be reapplied in any situation where names are used for pathway entities and events. Adoption of this CV would significantly improve naming consistency and readability, with consequent benefits for searching and data mining within and between databases. Database URL: http://www.reactome.org. © The Author(s) 2014. Published by Oxford University Press.

  16. A controlled vocabulary for pathway entities and events

    PubMed Central

    Jupe, Steve; Jassal, Bijay; Williams, Mark; Wu, Guanming

    2014-01-01

    Entities involved in pathways and the events they participate in require descriptive and unambiguous names that are often not available in the literature or elsewhere. Reactome is a manually curated open-source resource of human pathways. It is accessible via a website, available as downloads in standard reusable formats and via Representational State Transfer (REST)-ful and Simple Object Access Protocol (SOAP) application programming interfaces (APIs). We have devised a controlled vocabulary (CV) that creates concise, unambiguous and unique names for reactions (pathway events) and all the molecular entities they involve. The CV could be reapplied in any situation where names are used for pathway entities and events. Adoption of this CV would significantly improve naming consistency and readability, with consequent benefits for searching and data mining within and between databases. Database URL: http://www.reactome.org PMID:24951798

  17. Synthesis of a Series of Caffeic Acid Phenethyl Amide (CAPA) Fluorinated Derivatives: Comparison of Cytoprotective Effects to Caffeic Acid Phenethyl Ester (CAPE)

    DTIC Science & Technology

    2010-06-11

    cDivision of Medicinal Chemistry and Institute for Cellular and Molecular Biology , The University of Texas, Austin, TX 78712, USA a r t i c l e i n f o...centrated in honeybee propolis, has been found to be biologically active in a variety of pathways including cytoprotection against oxidative stress. CAPE

  18. Different sympathetic pathways control the metabolism of distinct bone envelopes.

    PubMed

    Bataille, Caroline; Mauprivez, Cédric; Haÿ, Eric; Baroukh, Brigitte; Brun, Adrian; Chaussain, Catherine; Marie, Pierre J; Saffar, Jean-Louis; Cherruau, Marc

    2012-05-01

    Bone remodeling, the mechanism that modulates bone mass adaptation, is controlled by the sympathetic nervous system through the catecholaminergic pathway. However, resorption in the mandible periosteum envelope is associated with cholinergic Vasoactive Intestinal Peptide (VIP)-positive nerve fibers sensitive to sympathetic neurotoxics, suggesting that different sympathetic pathways may control distinct bone envelopes. In this study, we assessed the role of distinct sympathetic pathways on rat femur and mandible envelopes. To this goal, adult male Wistar rats were chemically sympathectomized or treated with agonists/antagonists of the catecholaminergic and cholinergic pathways; femora and mandibles were sampled. Histomorphometric analysis showed that sympathectomy decreased the number of preosteoclasts and RANKL-expressing osteoblasts in mandible periosteum but had no effect on femur trabecular bone. In contrast, pharmacological stimulation or repression of the catecholaminergic cell receptors impacted the femur trabecular bone and mandible endosteal retromolar zone. VIP treatment of sympathectomized rats rescued the disturbances of the mandible periosteum and alveolar wall whereas the cholinergic pathway had no effect on the catecholaminergic-dependent envelopes. We also found that VIP receptor-1 was weakly expressed in periosteal osteoblasts in the mandible and was increased by VIP treatment, whereas osteoblasts of the retromolar envelope that was innervated only by tyrosine hydroxylase-immunoreactive fibers, constitutively expressed beta-2 adrenergic receptors. These data highlight the complexity of the sympathetic control of bone metabolism. Both the embryological origin of the bone (endochondral for the femur, membranous for the mandibular periosteum and the socket wall) and environmental factors specific to the innervated envelope may influence the phenotype of the sympathetic innervation. We suggest that an origin-dependent imprint of bone cells through

  19. Sonic hedgehog is cytoprotective against oxidative challenge in a cellular model of amyotrophic lateral sclerosis.

    PubMed

    Peterson, Randy; Turnbull, John

    2012-05-01

    We have previously demonstrated that primary cilia on spinal motor neurons are reduced in G93A SOD1 (mSOD) mice, a mouse model of amyotrophic lateral sclerosis (ALS). Sonic hedgehog (Shh) signaling involves the primary cilium and Shh has been shown to be cytoprotective in models of other neurodegenerative diseases. Thus, the Shh signaling pathway may bear further study in ALS. Accordingly, we established that interference with the Shh pathway (with the Shh antagonist cyclopamine or with miRNA 3245p) sensitized HT22 cells, while augmentation of the Shh pathway (with Shh or the Shh agonist purmorphamine) protected cells against hydrogen peroxide (H₂O₂) challenge. We ectopically expressed mSOD, human wild-type SOD1 (wtSOD), or an empty vector in HT22 cells. Compared to empty vector, wtSOD decreased cell death and mSOD increased cell death in response to H₂O₂ challenge. Treatment with cyclopamine or miRNA 3245p sensitized all three transfections to H₂O₂ challenge. Treatment with recombinant human Shh or purmorphamine decreased cell death after H₂O₂ challenge, an effect more pronounced in mSOD cells. Compared with empty vector, overexpression of wtSOD increased Shh and Gli transcript levels and increased activity in a Gli-responsive reporter assay. Overexpression of mSOD did not change Shh transcript levels, but decreased Gli transcript levels, especially Gli3, and reduced activity in a Gli reporter assay. These results suggest that overexpression of mSOD but not wtSOD reduces signaling in the Shh pathway and renders mSOD cells more susceptible to H₂O₂ challenge, and that treatment with Shh or Shh agonists is cytoprotective to mSOD cells. Shh or Shh agonists merit further consideration as potential therapy in ALS.

  20. Engineering Heteromaterials to Control Lithium Ion Transport Pathways

    SciTech Connect

    Liu, Yang; Vishniakou, Siarhei; Yoo, Jinkyoung; Dayeh, Shadi A.

    2015-12-21

    Safe and efficient operation of lithium ion batteries requires precisely directed flow of lithium ions and electrons to control the first directional volume changes in anode and cathode materials. Understanding and controlling the lithium ion transport in battery electrodes becomes crucial to the design of high performance and durable batteries. Recent work revealed that the chemical potential barriers encountered at the surfaces of heteromaterials play an important role in directing lithium ion transport at nanoscale. Here, we utilize in situ transmission electron microscopy to demonstrate that we can switch lithiation pathways from radial to axial to grain-by-grain lithiation through the systematic creation of heteromaterial combinations in the Si-Ge nanowire system. Lastly, our systematic studies show that engineered materials at nanoscale can overcome the intrinsic orientation-dependent lithiation, and open new pathways to aid in the development of compact, safe, and efficient batteries.

  1. Engineering Heteromaterials to Control Lithium Ion Transport Pathways

    DOE PAGES

    Liu, Yang; Vishniakou, Siarhei; Yoo, Jinkyoung; ...

    2015-12-21

    Safe and efficient operation of lithium ion batteries requires precisely directed flow of lithium ions and electrons to control the first directional volume changes in anode and cathode materials. Understanding and controlling the lithium ion transport in battery electrodes becomes crucial to the design of high performance and durable batteries. Recent work revealed that the chemical potential barriers encountered at the surfaces of heteromaterials play an important role in directing lithium ion transport at nanoscale. Here, we utilize in situ transmission electron microscopy to demonstrate that we can switch lithiation pathways from radial to axial to grain-by-grain lithiation through themore » systematic creation of heteromaterial combinations in the Si-Ge nanowire system. Lastly, our systematic studies show that engineered materials at nanoscale can overcome the intrinsic orientation-dependent lithiation, and open new pathways to aid in the development of compact, safe, and efficient batteries.« less

  2. Engineering Heteromaterials to Control Lithium Ion Transport Pathways

    SciTech Connect

    Liu, Yang; Vishniakou, Siarhei; Yoo, Jinkyoung; Dayeh, Shadi A.

    2015-12-21

    Safe and efficient operation of lithium ion batteries requires precisely directed flow of lithium ions and electrons to control the first directional volume changes in anode and cathode materials. Understanding and controlling the lithium ion transport in battery electrodes becomes crucial to the design of high performance and durable batteries. Some recent work revealed that the chemical potential barriers encountered at the surfaces of heteromaterials play an important role in directing lithium ion transport at nanoscale. We utilize in situ transmission electron microscopy to demonstrate that we can switch lithiation pathways from radial to axial to grain-by-grain lithiation through the systematic creation of heteromaterial combinations in the Si-Ge nanowire system. Furthermore, our systematic studies show that engineered materials at nanoscale can overcome the intrinsic orientation-dependent lithiation, and open new pathways to aid in the development of compact, safe, and efficient batteries.

  3. Engineering Heteromaterials to Control Lithium Ion Transport Pathways

    DOE PAGES

    Liu, Yang; Vishniakou, Siarhei; Yoo, Jinkyoung; ...

    2015-12-21

    Safe and efficient operation of lithium ion batteries requires precisely directed flow of lithium ions and electrons to control the first directional volume changes in anode and cathode materials. Understanding and controlling the lithium ion transport in battery electrodes becomes crucial to the design of high performance and durable batteries. Some recent work revealed that the chemical potential barriers encountered at the surfaces of heteromaterials play an important role in directing lithium ion transport at nanoscale. We utilize in situ transmission electron microscopy to demonstrate that we can switch lithiation pathways from radial to axial to grain-by-grain lithiation through themore » systematic creation of heteromaterial combinations in the Si-Ge nanowire system. Furthermore, our systematic studies show that engineered materials at nanoscale can overcome the intrinsic orientation-dependent lithiation, and open new pathways to aid in the development of compact, safe, and efficient batteries.« less

  4. Engineering Heteromaterials to Control Lithium Ion Transport Pathways

    PubMed Central

    Liu, Yang; Vishniakou, Siarhei; Yoo, Jinkyoung; Dayeh, Shadi A.

    2015-01-01

    Safe and efficient operation of lithium ion batteries requires precisely directed flow of lithium ions and electrons to control the first directional volume changes in anode and cathode materials. Understanding and controlling the lithium ion transport in battery electrodes becomes crucial to the design of high performance and durable batteries. Recent work revealed that the chemical potential barriers encountered at the surfaces of heteromaterials play an important role in directing lithium ion transport at nanoscale. Here, we utilize in situ transmission electron microscopy to demonstrate that we can switch lithiation pathways from radial to axial to grain-by-grain lithiation through the systematic creation of heteromaterial combinations in the Si-Ge nanowire system. Our systematic studies show that engineered materials at nanoscale can overcome the intrinsic orientation-dependent lithiation, and open new pathways to aid in the development of compact, safe, and efficient batteries. PMID:26686655

  5. Inhibition of caspase-9 aggravates acute liver injury through suppression of cytoprotective autophagy

    PubMed Central

    Guo, Rui; Lin, Bin; Pan, Jing Fei; Liong, Emily C.; Xu, Ai Min; Youdim, Moussa; Fung, Man Lung; So, Kwok Fai; Tipoe, George L.

    2016-01-01

    Acute liver disease is characterized by inflammation, oxidative stress and necrosis, which can greatly influence the long term clinical outcome and lead to liver failure or cancer. Here, we initially demonstrated the beneficial role of caspase-9-dependent autophagy in acute liver injury. Treatment with caspase-9 inhibitor z-LEHD-FMK in HepG2 cells, AML12 cells and C57BL/b6N mice exacerbated CCl4-induced acute hepatocellular damage, and also down-regulated autophagy markers expression levels, indicating that caspase-9 inhibition may aggravate acute liver damage by suppressing cytoprotective autophagy. CCl4 was used as an acute liver injury inducer which caused oxidative stress and apoptosis through up-regulation of HIF-1α, as well as triggered hepatic inflammation and necroptosis via TLR4/NF-κB pathway. Caspase-9 Thr125 site was firstly phosphorylated by ERK1/2 which subsequently activated the cytoprotective autophagy process to attenuate acute CCl4 injury. Caspase-9 inhibition further aggravated hepatic necroptosis through NF-κB expression, leading to increased pro-inflammatory mediators levels, suggesting a protective role of caspase-9-dependent autophagy in the inflammatory process as well as its possibility being a new therapeutic target for the treatment of acute liver injury. PMID:27580936

  6. The NRF2 transcriptional target, OSGIN1, contributes to monomethyl fumarate-mediated cytoprotection in human astrocytes

    PubMed Central

    Brennan, Melanie S.; Matos, Maria F.; Richter, Karl E.; Li, Bing; Scannevin, Robert H.

    2017-01-01

    Dimethyl fumarate (DMF) is indicated for the treatment of relapsing multiple sclerosis and may exert therapeutic effects via activation of the nuclear factor (erythroid-derived 2)-like 2 (NRF2) pathway. Following oral DMF administration, central nervous system (CNS) tissue is predominantly exposed to monomethyl fumarate (MMF), the bioactive metabolite of DMF, which can stabilize NRF2 and induce antioxidant gene expression; however, the detailed NRF2-dependent mechanisms modulated by MMF that lead to cytoprotection are unknown. Our data identify a mechanism for MMF-mediated cytoprotection in human astrocytes that functions in an OSGIN1-dependent manner, specifically via upregulation of the OSGIN1-61 kDa isoform. NRF2-dependent OSGIN1 expression induced P53 nuclear translocation following MMF administration, leading to cell-cycle inhibition and cell protection against oxidative challenge. This study provides mechanistic insight into MMF-mediated cytoprotection via NRF2, OSGIN1, and P53 in human CNS-derived cells and contributes to our understanding of how DMF may act clinically to ameliorate pathological processes in neurodegenerative disease. PMID:28181536

  7. Striatal direct and indirect pathways control decision-making behavior.

    PubMed

    Macpherson, Tom; Morita, Makiko; Hikida, Takatoshi

    2014-01-01

    Despite our ever-changing environment, animals are remarkably adept at selecting courses of action that are predictive of optimal outcomes. While requiring the contribution of a number of brain regions, a vast body of evidence implicates striatal mechanisms of associative learning and action selection to be critical to this ability. While numerous models of striatal-based decision-making have been developed, it is only recently that we have begun to understand the precise contributions of specific subpopulations of striatal neurons. Studies utilizing contemporary cell-type-specific technologies indicate that striatal output pathways play distinct roles in controlling goal-directed and social behaviors. Here we review current models of striatal-based decision-making, discuss recent developments in defining the functional roles of striatal output pathways, and assess how striatal dysfunction may contribute to the etiology of various neuropathologies.

  8. Control the kinetics and pathway of insulin fibril formation

    NASA Astrophysics Data System (ADS)

    Zheng, Zhongli; Jing, Benxin; Zhu, Y. Elaine

    2012-02-01

    Protein fibrils have been proposed as possible toxic agents for many amyloid related diseases, such as Alzheimer's disease, however the reaction pathway toward the amyloid fibrillation remain inadequately understood. In this work, we examine the conformational transition of human insulin as the model amyloid protein by single-molecule fluorescence spectroscopy and imaging. By controlling the pH cycling, insulin monomer and oligomers are indentified at given pH variation condition. Furthermore, low frequency ac-electric fields are employed to control the insulin aggregation from its monomers in a microchannel. It is observed that lag time to induce insulin fibrillation can be significantly shortened, in compassion to the commonly used cooling and seeding methods, and exhibits a strong dependence on applied ac-field strength. Additionally, the structure of insulin aggregates under ac-electric fields is observed to be drastically different from that under the temperature control.

  9. Sulglycotide displays cytoprotective activity in rat gastric mucosa.

    PubMed

    Niada, R; Mantovani, M; Prino, G; Omini, C; Berti, F

    1983-01-01

    Sulglycotide, a well known antisecretory and antiulcer compound, has been further investigated for its ability to protect rat gastric mucosa against extensive necrosis induced by absolute ethanol, NaOH (0.2N) and NaCl (30%). Sulglycotide, which has been compared with cimetidine, displays a dose-dependent cytoprotective activity against the above necrotizing agents. The results obtained indicate that Sulglycotide requires a normal prostaglandin biosynthetic process in order to manifest its antiulcer activity. In fact gastric mucosa from animals treated with Sulglycotide releases in vitro a greater amount of PGl2-like activity; and furthermore no protection was observed against gastric lesions induced by indomethacin. As far as the mode of action of Sulglycotide is concerned it is tempting to speculate that the compound may interfere with prostaglandin degradation or it may trigger an adaptive cytoprotection which is important in maintaining the cellular integrity of rat gastric mucosa.

  10. Preface: cardiac control pathways: signaling and transport phenomena.

    PubMed

    Sideman, Samuel

    2008-03-01

    Signaling is part of a complex system of communication that governs basic cellular functions and coordinates cellular activity. Transfer of ions and signaling molecules and their interactions with appropriate receptors, transmembrane transport, and the consequent intracellular interactions and functional cellular response represent a complex system of interwoven phenomena of transport, signaling, conformational changes, chemical activation, and/or genetic expression. The well-being of the cell thus depends on a harmonic orchestration of all these events and the existence of control mechanisms that assure the normal behavior of the various parameters involved and their orderly expression. The ability of cells to sustain life by perceiving and responding correctly to their microenvironment is the basis for development, tissue repair, and immunity, as well as normal tissue homeostasis. Natural deviations, or human-induced interference in the signaling pathways and/or inter- and intracellular transport and information transfer, are responsible for the generation, modulation, and control of diseases. The present overview aims to highlight some major topics of the highly complex cellular information transfer processes and their control mechanisms. Our goal is to contribute to the understanding of the normal and pathophysiological phenomena associated with cardiac functions so that more efficient therapeutic modalities can be developed. Our objective in this volume is to identify and enhance the study of some basic passive and active physical and chemical transport phenomena, physiological signaling pathways, and their biological consequences.

  11. Optogenetic control of the Dab1 signaling pathway

    PubMed Central

    Wang, Liang; Cooper, Jonathan A.

    2017-01-01

    The Reelin-Dab1 signaling pathway regulates development of the mammalian brain, including neuron migrations in various brain regions, as well as learning and memory in adults. Extracellular Reelin binds to cell surface receptors and activates phosphorylation of the intracellular Dab1 protein. Dab1 is required for most effects of Reelin, but Dab1-independent pathways may contribute. Here we developed a single-component, photoactivatable Dab1 (opto-Dab1) by using the blue light-sensitive dimerization/oligomerization property of A. thaliana Cryptochrome 2 (Cry2). Opto-Dab1 can activate downstream signals rapidly, locally, and reversibly upon blue light illumination. The high spatiotemporal resolution of the opto-Dab1 probe also allows us to control membrane protrusion, retraction and ruffling by local illumination in both COS7 cells and in primary neurons. This shows that Dab1 activation is sufficient to orient cell movement in the absence of other signals. Opto-Dab1 may be useful to study the biological functions of the Reelin-Dab1 signaling pathway both in vitro and in vivo. PMID:28272509

  12. Nanoparticle hardness controls the internalization pathway for drug delivery

    NASA Astrophysics Data System (ADS)

    Li, Ye; Zhang, Xianren; Cao, Dapeng

    2015-01-01

    Nanoparticle (NP)-based drug delivery systems offer fundamental advantages over current therapeutic agents that commonly display a longer circulation time, lower toxicity, specific targeted release, and greater bioavailability. For successful NP-based drug delivery it is essential that the drug-carrying nanocarriers can be internalized by the target cells and transported to specific sites, and the inefficient internalization of nanocarriers is often one of the major sources for drug resistance. In this work, we use the dissipative particle dynamics simulation to investigate the effect of NP hardness on their internalization efficiency. Three simplified models of NP platforms for drug delivery, including polymeric NP, liposome and solid NP, are designed here to represent increasing nanocarrier hardness. Simulation results indicate that NP hardness controls the internalization pathway for drug delivery. Rigid NPs can enter the cell by a pathway of endocytosis, whereas for soft NPs the endocytosis process can be inhibited or frustrated due to wrapping-induced shape deformation and non-uniform ligand distribution. Instead, soft NPs tend to find one of three penetration pathways to enter the cell membrane via rearranging their hydrophobic and hydrophilic segments. Finally, we show that the interaction between nanocarriers and drug molecules is also essential for effective drug delivery.

  13. Nanoparticle hardness controls the internalization pathway for drug delivery.

    PubMed

    Li, Ye; Zhang, Xianren; Cao, Dapeng

    2015-02-14

    Nanoparticle (NP)-based drug delivery systems offer fundamental advantages over current therapeutic agents that commonly display a longer circulation time, lower toxicity, specific targeted release, and greater bioavailability. For successful NP-based drug delivery it is essential that the drug-carrying nanocarriers can be internalized by the target cells and transported to specific sites, and the inefficient internalization of nanocarriers is often one of the major sources for drug resistance. In this work, we use the dissipative particle dynamics simulation to investigate the effect of NP hardness on their internalization efficiency. Three simplified models of NP platforms for drug delivery, including polymeric NP, liposome and solid NP, are designed here to represent increasing nanocarrier hardness. Simulation results indicate that NP hardness controls the internalization pathway for drug delivery. Rigid NPs can enter the cell by a pathway of endocytosis, whereas for soft NPs the endocytosis process can be inhibited or frustrated due to wrapping-induced shape deformation and non-uniform ligand distribution. Instead, soft NPs tend to find one of three penetration pathways to enter the cell membrane via rearranging their hydrophobic and hydrophilic segments. Finally, we show that the interaction between nanocarriers and drug molecules is also essential for effective drug delivery.

  14. Cytochrome P450 2A5 and bilirubin: Mechanisms of gene regulation and cytoprotection

    SciTech Connect

    Kim, Sangsoo Daniel; Antenos, Monica; Squires, E. James; Kirby, Gordon M.

    2013-07-15

    Bilirubin (BR) has recently been identified as the first endogenous substrate for cytochrome P450 2A5 (CYP2A5) and it has been suggested that CYP2A5 plays a major role in BR clearance as an alternative mechanism to BR conjugation by uridine-diphosphate glucuronyltransferase 1A1. This study investigated the mechanisms of Cyp2a5 gene regulation by BR and the cytoprotective role of CYP2A5 in BR hepatotoxicity. BR induced CYP2A5 expression at the mRNA and protein levels in a dose-dependent manner in primary mouse hepatocytes. BR treatment also caused nuclear translocation of Nuclear factor-E2 p45-related factor 2 (Nrf2) in hepatocytes. In reporter assays, BR treatment of primary hepatocytes transfected with a Cyp2a5 promoter-luciferase reporter construct resulted in a 2-fold induction of Cyp2a5 reporter activity. Furthermore, cotransfection of the hepatocytes with a Nrf2 expression vector without BR treatment resulted in an increase in Cyp2a5 reporter activity of approximately 2-fold and BR treatment of Nrf2 cotransfectants further increased reporter activity by 4-fold. In addition, site-directed mutation of the ARE in the reporter construct completely abolished both the BR- and Nrf2-mediated increases in reporter activity. The cytoprotective role of CYP2A5 against BR-mediated apoptosis was also examined in Hepa 1–6 cells that lack endogenous CYP2A5. Transient overexpression of CYP2A5 partially blocked BR-induced caspase-3 cleavage in Hepa 1–6 cells. Furthermore, in vitro degradation of BR was increased by microsomes from Hepa 1–6 cells overexpressing CYP2A5 compared to control cells transfected with an empty vector. Collectively, these results suggest that Nrf2-mediated CYP2A5 transactivation in response to BR may provide an additional mechanism for adaptive cytoprotection against BR hepatotoxicity. - Highlights: • The mechanism of Cyp2a5 gene regulation by BR was investigated. • The cytoprotective role of CYP2A5 in BR hepatotoxicity was determined. • BR

  15. Thrombomodulin exerts cytoprotective effect on low-dose UVB-irradiated HaCaT cells

    SciTech Connect

    Iwata, Masahiro; Kawahara, Ko-ichi; Kawabata, Hisashi; Ito, Takashi; Mera, Kentaro; Biswas, Kamal Krishna; Tancharoen, Salunya; Higashi, Yuko; Kikuchi, Kiyoshi; Hashiguchi, Teruto

    2008-12-12

    Thrombomodulin (TM) is an endothelial cell surface anticoagulant glycoprotein that performs antimetastatic, angiogenic, adhesive, and anti-inflammatory functions in various tissues. It is also expressed in epidermal keratinocytes. We found that a physiological dose (10 mJ/cm{sup 2}) of mid-wavelength ultraviolet irradiation (UVB) significantly induced TM expression via the p38mitogen-activated protein kinase (MAPK)/cyclic AMP response element (CRE) signaling pathway in the epidermal keratinocyte cell line HaCaT; this shows that TM regulates the survival of HaCaT cells. SB203580, a p38MAPK inhibitor, significantly decreased TM expression and the viability of cells exposed to UVB. Furthermore, overexpression of TM markedly increased cell viability, and it was abrogated by TM small interfering RNA (siRNA), suggesting that TM may play an important role in exerting cytoprotective effect on epidermal keratinocytes against low-dose UVB.

  16. Cytoprotective effects of fisetin against hypoxia-induced cell death in PC12 cells.

    PubMed

    Chen, Pei-Yi; Ho, Yi-Ru; Wu, Ming-Jiuan; Huang, Shun-Ping; Chen, Po-Kong; Tai, Mi-Hsueh; Ho, Chi-Tang; Yen, Jui-Hung

    2015-01-01

    Fisetin (3,7,3',4'-tetrahydroxyflavone), a flavonol compound of flavonoids, exhibits a broad spectrum of biological activities including anti-oxidant, anti-inflammatory, anti-cancer and neuroprotective effects. The aim of this study is to investigate the cytoprotective effect of fisetin and the underlying molecular mechanism against hypoxia-induced cell death in PC12 cells. The results of this study showed that fisetin significantly restored the cell viability of PC12 cells under both cobalt chloride (CoCl₂)- and low oxygen-induced hypoxic conditions. Treatment with fisetin successfully reduced the CoCl₂-mediated reactive oxygen species (ROS) production, which was accompanied by an increase in the cell viability of PC12 cells. Furthermore, we found that treatment of PC12 cells with fisetin markedly upregulated hypoxia-inducible factor 1α (HIF-1α), its nuclear accumulation and the hypoxia-response element (HRE)-driven transcriptional activation. The fisetin-mediated cytoprotection during CoCl₂ exposure was significantly attenuated through the administration of HIF-1α siRNA. Moreover, we demonstrated that MAPK/ERK kinase 1/2 (MEK1/2), p38 MAPK and phosphatidylinositol 3-kinase (PI3 K) inhibitors significantly blocked the increase in cell survival that was induced by fisetin treatment under hypoxic conditions. Consistently, increased phosphorylation of ERK, p38 and Akt proteins was observed in PC12 cells treated with fisetin. However, the fisetin-induced HRE-driven transcription was not affected by inhibition of these kinase signaling pathways. Current results reveal for the first time that fisetin promotes cell survival and protects against hypoxia-induced cell death through ROS scavenging and the activation of HIF1α-, MAPK/ERK-, p38 MAPK- and PI3 K/Akt-dependent signaling pathways in PC12 cells.

  17. Viral Evasion and Manipulation of Host RNA Quality Control Pathways.

    PubMed

    Hogg, J Robert

    2016-08-15

    Viruses have evolved diverse strategies to maximize the functional and coding capacities of their genetic material. Individual viral RNAs are often used as substrates for both replication and translation and can contain multiple, sometimes overlapping open reading frames. Further, viral RNAs engage in a wide variety of interactions with both host and viral proteins to modify the activities of important cellular factors and direct their own trafficking, packaging, localization, stability, and translation. However, adaptations increasing the information density of small viral genomes can have unintended consequences. In particular, viral RNAs have developed features that mark them as potential targets of host RNA quality control pathways. This minireview focuses on ways in which viral RNAs run afoul of the cellular mRNA quality control and decay machinery, as well as on strategies developed by viruses to circumvent or exploit cellular mRNA surveillance.

  18. Viral Evasion and Manipulation of Host RNA Quality Control Pathways

    PubMed Central

    2016-01-01

    Viruses have evolved diverse strategies to maximize the functional and coding capacities of their genetic material. Individual viral RNAs are often used as substrates for both replication and translation and can contain multiple, sometimes overlapping open reading frames. Further, viral RNAs engage in a wide variety of interactions with both host and viral proteins to modify the activities of important cellular factors and direct their own trafficking, packaging, localization, stability, and translation. However, adaptations increasing the information density of small viral genomes can have unintended consequences. In particular, viral RNAs have developed features that mark them as potential targets of host RNA quality control pathways. This minireview focuses on ways in which viral RNAs run afoul of the cellular mRNA quality control and decay machinery, as well as on strategies developed by viruses to circumvent or exploit cellular mRNA surveillance. PMID:27226372

  19. Electrical control of optical emitter relaxation pathways enabled by graphene

    NASA Astrophysics Data System (ADS)

    Tielrooij, K. J.; Orona, L.; Ferrier, A.; Badioli, M.; Navickaite, G.; Coop, S.; Nanot, S.; Kalinic, B.; Cesca, T.; Gaudreau, L.; Ma, Q.; Centeno, A.; Pesquera, A.; Zurutuza, A.; de Riedmatten, H.; Goldner, P.; García de Abajo, F. J.; Jarillo-Herrero, P.; Koppens, F. H. L.

    2015-03-01

    Controlling the energy flow processes and the associated energy relaxation rates of a light emitter is of fundamental interest and has many applications in the fields of quantum optics, photovoltaics, photodetection, biosensing and light emission. Advanced dielectric, semiconductor and metallic systems have been developed to tailor the interaction between an emitter and its environment. However, active control of the energy flow from an emitter into optical, electronic or plasmonic excitations has remained challenging. Here, we demonstrate in situ electrical control of the relaxation pathways of excited erbium ions, which emit light at the technologically relevant telecommunication wavelength of 1.5 μm. By placing the erbium at a few nanometres distance from graphene, we modify the relaxation rate by more than a factor of three, and control whether the emitter decays into electron-hole pairs, emitted photons or graphene near-infrared plasmons, confined to <15 nm from the graphene sheet. These capabilities to dictate optical energy transfer processes through electrical control of the local density of optical states constitute a new paradigm for active (quantum) photonics and can be applied using any combination of light emitters and two-dimensional materials.

  20. Pentadecapeptide BPC 157, cimetidine, ranitidine, bromocriptine, and atropine effect in cysteamine lesions in totally gastrectromized rats: a model for cytoprotective studies.

    PubMed

    Sikirić, P; Mikus, D; Seiwerth, S; Grabarević, Z; Rucman, R; Petek, M; Jagić, V; Turković, B; Rotkvić, I; Mise, S; Zoricić, I; Perić, J; Konjevoda, P; Perović, D; Jurina, L; Hanzevacki, M; Separović, J; Gjurasin, M; Jadrijević, S; Jelovac, N; Miklić, P; Buljat, G; Marović, A

    1997-05-01

    A superior effectiveness in various lesion assays was noted for the novel pentadecapeptide BPC 157, originated from human gastric juice protein (BPC) and claimed to be a cytoprotective agent. From this viewpoint, as a previously untreated experimental improvement to create an acid-free environmental for cytoprotection studies, total gastrectomy was done 24 hr before the ulcerogenic procedure. In the absence of stomach and gastric acid, the damaging effects of cysteamine (400 mg/kg subcutaneously, death 24 hr thereafter), to date thought to be an acid-related duodenal ulcerogen, and the BPC 157 cytoprotective effect (10 microg or 10 ng/kg intraperitoneally) were further challenged. BPC 157 was compared with reference agents [cimetidine (50), ranitidine (10), omeprazole (10), bromocriptine (10) and atropine (10) (mg/kg intraperitoneally, 1 hr before cysteamine] known to be also cytoprotective. In naive rats, with intact stomach, all of them showed a strong beneficial effect. Interestingly, in gastrectomized animals, the application of BPC 157 or the reference agents before cysteamine significantly prevented the otherwise severe duodenal lesion development noted in the control gastrectomized cysteamine rats. In groups without cysteamine, no lesions were noted (laparotomy, gastrectomy only, 24 or 48 hr postsurgical period), nor was lesion potentiation seen in cysteamine-treated laparotomized animals. In summary, these findings--equal damaging effect of cysteamine and equal protection of pentadecapeptide BPC 157 and reference agents in gastrectomized and rats with intact stomach--seem to be particularly relevant for a cytoprotective viewpoint. Without a stomach, the cysteamine damaging effect was convincingly defined as an essential gastric acid-independent injury (analogous to ethanol gastric lesions). Likewise, a high "cytoprotective capacity," apparently acid independent, common for all tested agents (novel pentadecapeptide BPC 157, cimetidine, ranitidine, omeprazole

  1. Cereblon is recruited to aggresome and shows cytoprotective effect against ubiquitin-proteasome system dysfunction.

    PubMed

    Sawamura, Naoya; Wakabayashi, Satoru; Matsumoto, Kodai; Yamada, Haruka; Asahi, Toru

    2015-09-04

    Cereblon (CRBN) is encoded by a candidate gene for autosomal recessive nonsyndromic intellectual disability (ID). The nonsense mutation, R419X, causes deletion of 24 amino acids at the C-terminus of CRBN, leading to mild ID. Although abnormal CRBN function may be associated with ID disease onset, its cellular mechanism is still unclear. Here, we examine the role of CRBN in aggresome formation and cytoprotection. In the presence of a proteasome inhibitor, exogenous CRBN formed perinuclear inclusions and co-localized with aggresome markers. Endogenous CRBN also formed perinuclear inclusions under the same condition. Treatment with a microtubule destabilizer or an inhibitor of the E3 ubiquitin ligase activity of CRBN blocked formation of CRBN inclusions. Biochemical analysis showed CRBN containing inclusions were high-molecular weight, ubiquitin-positive. CRBN overexpression in cultured cells suppressed cell death induced by proteasome inhibitor. Furthermore, knockdown of endogenous CRBN in cultured cells increased cell death induced by proteasome inhibitor, compared with control cells. Our results show CRBN is recruited to aggresome and has functional roles in cytoprotection against ubiquitin-proteasome system impaired condition.

  2. Antioxidant and Cytoprotective Effects of Lotus (Nelumbo nucifera) Leaves Phenolic Fraction.

    PubMed

    Lee, Da-Bin; Kim, Do-Hyung; Je, Jae-Young

    2015-03-01

    Phenolic rich ethyl acetate fraction (EAF) from lotus leaves was prepared and its bioactive components, antioxidant and cytoprotective effects were investigated. EAF showed high total phenolic content and flavonoid content and contained rutin (11,331.3±4.5 mg/100 g EAF), catechin (10,853.8±5.8 mg/100 g EAF), sinapic acid (1,961.3±5.6 mg/100 g EAF), chlorogenic acid (631.9±2.3 mg/100 g EAF), syringic acid (512.3±2.5 mg/100 g EAF), and quercetin (415.0±2.1 mg/100 g EAF). EAF exerted the IC50 of 4.46 μg/mL and 5.35 μg/mL toward DPPH and ABTS cation radicals, respectively, and showed strong reducing power, which was better than that of ascorbic acid, a positive control. Additionally, EAF protected hydroxyl radical-induced DNA damage indicated by the conversion of supercoiled pBR322 plasmid DNA to the open circular form and inhibited lipid peroxidation of polyunsaturated fatty acid in a linoleic acid emulsion. In cultured hepatocytes, EAF exerted a cytoprotective effect against oxidative stress by inhibiting intracellular reactive oxygen species formation and membrane lipid peroxidation. In addition, depletion of glutathione under oxidative stress was remarkably restored by treatment with EAF. The results suggest that EAF have great potential to be used against oxidative stress-induced health conditions.

  3. Neurophysiological Pathways to Obesity: Below Awareness and Beyond Individual Control

    PubMed Central

    Cohen, Deborah A.

    2008-01-01

    A global obesity epidemic is occurring simultaneously with ongoing increases in the availability and salience of food in the environment. Obesity is increasing across all socioeconomic groups and educational levels and occurs even among individuals with the highest levels of education and expertise in nutrition and related fields. Given these circumstances, it is plausible that excessive food consumption occurs in ways that defy personal insight or are below individual awareness. The current food environment stimulates automatic reflexive responses that enhance the desire to eat and increase caloric intake, making it exceedingly difficult for individuals to resist, especially because they may not be aware of these influences. This article identifies 10 neurophysiological pathways that can lead people to make food choices subconsciously or, in some cases, automatically. These pathways include reflexive and uncontrollable neurohormonal responses to food images, cues, and smells; mirror neurons that cause people to imitate the eating behavior of others without awareness; and limited cognitive capacity to make informed decisions about food. Given that people have limited ability to shape the food environment individually and no ability to control automatic responses to food-related cues that are unconsciously perceived, it is incumbent upon society as a whole to regulate the food environment, including the number and types of food-related cues, portion sizes, food availability, and food advertising. PMID:18586908

  4. (Controls of the plant endomembrane-secretory pathway): Performance report

    SciTech Connect

    Not Available

    1987-01-01

    This project has been directed towards an understanding of the cellular and molecular mechanisms by which higher plants control the composition of the plasma membrane, through analysis of the biosynthesis, modification and targeting of plasma membrane proteins and glycoproteins. We have undertaken an identification of molecular markers both for the plasma membrane and for the biosynthetic processes, and the development of techniques for the isolation of conditional-lethal mutants defective at defined stages within the endomembrane-secretory pathway responsible for the biosynthesis, modification and targeting of plasma membrane proteins and glycoproteins. For the identification of molecular markers for the plasma membrane, monoclonal antibodies directed against epitopes present at the plant cell surface have been developed. Novel molecular markers for the plant plasma membrane and for the endomembrane-secretory pathway have been sought. Methods for the analysis of beta-glucuronidase in higher plants have been developed. These technologies have involved the use of flow cytometry and fluorescence-activated cell sorting. In addition, we have been investigating the feasibility of expression of animal plasma membrane marker proteins in plants, specifically the VSV G-protein. 5 refs., 6 figs.

  5. Cytoprotective effect of pirenzepine and palm wine on rats gastric mucosa.

    PubMed

    Ibu, J O; Obuforoibo, A A; Ezeamuzie, I C; Ngeribara, C O

    1986-01-01

    Pirenzepine (Gastrozepin--Boechringer Ingelheim) is selective antimuscarinic blocker (MI-blocker) which has been used in the treatment of peptic ulcer because of its ability to reduce gastric acid secretion. But pirenzepine has also been found to have a cytoprotective effect on gastric mucosa in rats. The aim of the present investigation was to find out if palm wine also has any cytoprotective effect on rat gastric mucosa. Gastric mucosal ulcerations were induced with absolute ethanol. It was found that Pirenzepine induced 57% cytoprotection while palm wine induced 24% cytoprotection in rat gastric mucosa. The protection with the latter substance was not statistically significant, while the effect with pirenzepine was significant.

  6. A Central Neural Pathway Controlling Odor Tracking in Drosophila

    PubMed Central

    Slater, Gemma; Levy, Peter; Chan, K.L. Andrew

    2015-01-01

    Chemotaxis is important for the survival of most animals. How the brain translates sensory input into motor output beyond higher olfactory processing centers is largely unknown. We describe a group of excitatory neurons, termed Odd neurons, which are important for Drosophila larval chemotaxis. Odd neurons receive synaptic input from projection neurons in the calyx of the mushroom body and project axons to the central brain. Functional imaging shows that some of the Odd neurons respond to odor. Larvae in which Odd neurons are silenced are less efficient at odor tracking than controls and sample the odor space more frequently. Larvae in which the excitability of Odd neurons is increased are better at odor intensity discrimination and odor tracking. Thus, the Odd neurons represent a distinct pathway that regulates the sensitivity of the olfactory system to odor concentrations, demonstrating that efficient chemotaxis depends on processing of odor strength downstream of higher olfactory centers. PMID:25653345

  7. A central neural pathway controlling odor tracking in Drosophila.

    PubMed

    Slater, Gemma; Levy, Peter; Chan, K L Andrew; Larsen, Camilla

    2015-02-04

    Chemotaxis is important for the survival of most animals. How the brain translates sensory input into motor output beyond higher olfactory processing centers is largely unknown. We describe a group of excitatory neurons, termed Odd neurons, which are important for Drosophila larval chemotaxis. Odd neurons receive synaptic input from projection neurons in the calyx of the mushroom body and project axons to the central brain. Functional imaging shows that some of the Odd neurons respond to odor. Larvae in which Odd neurons are silenced are less efficient at odor tracking than controls and sample the odor space more frequently. Larvae in which the excitability of Odd neurons is increased are better at odor intensity discrimination and odor tracking. Thus, the Odd neurons represent a distinct pathway that regulates the sensitivity of the olfactory system to odor concentrations, demonstrating that efficient chemotaxis depends on processing of odor strength downstream of higher olfactory centers.

  8. Metabolic control of signalling pathways and metabolic auto-regulation.

    PubMed

    Lorendeau, Doriane; Christen, Stefan; Rinaldi, Gianmarco; Fendt, Sarah-Maria

    2015-08-01

    Metabolic alterations have emerged as an important hallmark in the development of various diseases. Thus, understanding the complex interplay of metabolism with other cellular processes such as cell signalling is critical to rationally control and modulate cellular physiology. Here, we review in the context of mammalian target of rapamycin, AMP-activated protein kinase and p53, the orchestrated interplay between metabolism and cellular signalling as well as transcriptional regulation. Moreover, we discuss recent discoveries in auto-regulation of metabolism (i.e. how metabolic parameters such as metabolite levels activate or inhibit enzymes and thus metabolic pathways). Finally, we review functional consequences of post-translational modification on metabolic enzyme abundance and/or activities.

  9. Fault-controlled hydrocarbon pathways in the Monterey Formation, California

    SciTech Connect

    Dholkakia, S.K.; Aydin, A.; Pollard, D.D.; Zoback, M.D.

    1998-08-01

    Field studies of low-permeability siliceous shale units of the Monterey Formation in the southern San Joaquin Valley and coastal California show evidence for fault control on hydrocarbon transport important for both migration and production. Shearing along preexisting discontinuities, such as bedding planes and joints, locally increases permeability in the sheared zone and surrounding fractured rock. As the rock is subjected to shear, it begins to systematically fragment and subsequently to brecciate, thereby creating interconnected voids for hydrocarbon transport. A outcrop-based conceptual model for the development of hydrocarbon pathways in the Monterey Formation is applied to the subsurface using formation microscanner (FMS) data and core. Bed-parallel breccia zones are identified in the Antelope Shale at Buena Vista Hills oil field.

  10. Novel cytoprotective mechanism of anti-parkinsonian drug deprenyl: PI3K and Nrf2-derived induction of antioxidative proteins

    SciTech Connect

    Nakaso, Kazuhiro . E-mail: kazuhiro@grape.med.tottori-u.ac.jp; Nakamura, Chiharu; Sato, Hiromi; Imamura, Keiko; Takeshima, Takao; Nakashima, Kenji

    2006-01-20

    Neuroprotection has received considerable attention as a strategy for the treatment of Parkinson's disease (PD). Deprenyl (Selegiline) is a promising candidate for neuroprotection; however, its cytoprotective mechanism has not been fully clarified. Here, we report a novel cytoprotective mechanism of deprenyl involving PI3K and Nrf2-mediated induction of oxidative stress-related proteins. Deprenyl increased the expression of HO-1, PrxI, TrxI, TrxRxI, {gamma}GCS, and p62/A170 in SH-SY5Y cells. Deprenyl also induced the nuclear accumulation of Nrf2 and increased the binding activity of Nrf2 to the enhancer region of human genomic HO-1. The Nrf2-mediated induction of antioxidative molecules was controlled by PI3K. Indeed, furthermore, neurotrophin receptor TrkB was identified as an upstream signal for PI3K-Nrf2 activation by deprenyl. These results suggest that the cytoprotective effect of deprenyl is, in part, dependent on Nrf2-mediated induction of antioxidative proteins, suggesting that activation of the PI3K-Nrf2 system may be a useful therapeutic strategy for PD.

  11. Signalling pathways involved in the control of sperm cell volume.

    PubMed

    Petrunkina, A M; Harrison, R A P; Tsolova, M; Jebe, E; Töpfer-Petersen, E

    2007-01-01

    The ability to maintain cellular volume is an important general physiological function, which is achieved by specific molecular mechanisms. Hypotonically induced swelling results in the opening of K+ and Cl- ion channels, through which these ions exit with accompanying water loss. This process is known as regulatory volume decrease (RVD). The molecular mechanisms that control the opening of the ion channels in spermatozoa are as yet poorly understood. The present study investigated pathways of osmo-signalling using boar spermatozoa as a model. Spermatozoa were diluted into isotonic and hypotonic Hepes-buffered saline in the presence or absence of effector drugs, and at predetermined intervals volume measurements were performed electronically. Treatment with protein kinase C (PKC) inhibitors staurosporine, bismaleimide I and bismaleimide X led to dose-dependent increases of both isotonic and hypotonic volumes (P<0.05). However, as the isotonic volume was affected more than the hypotonic volume, the kinase inhibitors appeared to improve RVD, whereas activation of PKC with phorbol dibutyrate blocked RVD. The increase in isotonic cell volume induced by bismaleimide X was observed in chloride-containing medium but not in the medium in which chloride was replaced by sulphate, implying that PKC was involved in the control of chloride channel activity, e.g. by closing the channel after volume adjustment. The protein phosphatase PP1/PP2 inhibitors calyculin and okadaic acid increased the isotonic volume only slightly but they greatly increased the relative cell volume and blocked RVD. The activation of RVD processes was found to be cAMP-dependent; incubation with forskolin and papaverine improved volume regulation. Moreover, papaverine was able to overcome the negative effect of protein phosphatase inhibitors. The mechanism of sperm RVD appears to involve (a) alterations in protein phosphorylation/dephosphorylation balance brought about by PKC and PP1 and (b) a c

  12. Metabolite Valves: Dynamic Control of Metabolic Flux for Pathway Engineering

    NASA Astrophysics Data System (ADS)

    Prather, Kristala

    2015-03-01

    Microbial strains have been successfully engineered to produce a wide variety of chemical compounds, several of which have been commercialized. As new products are targeted for biological synthesis, yield is frequently considered a primary driver towards determining feasibility. Theoretical yields can be calculated, establishing an upper limit on the potential conversion of starting substrates to target compounds. Such yields typically ignore loss of substrate to byproducts, with the assumption that competing reactions can be eliminated, usually by deleting the genes encoding the corresponding enzymes. However, when an enzyme encodes an essential gene, especially one involved in primary metabolism, deletion is not a viable option. Reducing gene expression in a static fashion is possible, but this solution ignores the metabolic demand needed for synthesis of the enzymes required for the desired pathway. We have developed Metabolite valves to address this challenge. The valves are designed to allow high flux through the essential enzyme during an initial period where growth is favored. Following an external perturbation, enzyme activity is then reduced, enabling a higher precursor pool to be diverted towards the pathway of interest. We have designed valves with control at both the transcriptional and post-translational levels. In both cases, key enzymes in glucose metabolism are regulated, and two different compounds are targeted for heterologous production. We have measured increased concentrations of intracellular metabolites once the valve is closed, and have demonstrated that these increased pools lead to increased product yields. These metabolite valves should prove broadly useful for dynamic control of metabolic flux, resulting in improvements in product yields.

  13. Cytoprotection of Human Endothelial Cells Against Oxidative Stress by 1-[2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oyl]imidazole (CDDO-Im): Application of Systems Biology to Understand the Mechanism of Action

    DTIC Science & Technology

    2014-04-03

    and exogenous oxidants, electrophiles , and toxicants. Activation of this pathway was reported to facilitate the induction of HMOX1 (Heiss et al., 2009...cytoprotective effect of caffeic acid phenethyl ester (CAPE) and fluorinated derivatives: effects on heme oxygenase-1 induction and antioxidant

  14. Hormonal signaling and signal pathway crosstalk in the control of myometrial calcium dynamics

    PubMed Central

    Sanborn, Barbara M.

    2007-01-01

    Understanding the basis for the control of myometrial contractant and relaxant signaling pathways is important to understanding how to manage myometrial contractions. Signaling pathways are influenced by the level of expression of the signals and signal pathway components, the location of these components in the appropriate subcellular environment, and covalent modification. Crosstalk between these pathways regulates the effectiveness of signal transduction and represents an important way by which hormones can regulate phenotype. This review deals primarily with signaling pathways that control Ca2+ entry and intracellular release, as well as the interplay between these pathways. PMID:17627855

  15. Cyclic Dinucleotide-Controlled Regulatory Pathways in Streptomyces Species

    PubMed Central

    2015-01-01

    The cyclic dinucleotides cyclic 3′,5′-diguanylate (c-di-GMP) and cyclic 3′,5′-diadenylate (c-di-AMP) have emerged as key components of bacterial signal transduction networks. These closely related second messengers follow the classical general principles of nucleotide signaling by integrating diverse signals into regulatory pathways that control cellular responses to changing environments. They impact distinct cellular processes, with c-di-GMP having an established role in promoting bacterial adhesion and inhibiting motility and c-di-AMP being involved in cell wall metabolism, potassium homeostasis, and DNA repair. The involvement of c-dinucleotides in the physiology of the filamentous, nonmotile streptomycetes remained obscure until recent discoveries showed that c-di-GMP controls the activity of the developmental master regulator BldD and that c-di-AMP determines the level of the resuscitation-promoting factor A(RpfA) cell wall-remodelling enzyme. Here, I summarize our current knowledge of c-dinucleotide signaling in Streptomyces species and highlight the important roles of c-di-GMP and c-di-AMP in the biology of these antibiotic-producing, multicellular bacteria. PMID:26216850

  16. Mechanism of phytoestrogen puerarin-mediated cytoprotection following oxidative injury: Estrogen receptor-dependent up-regulation of PI3K/Akt and HO-1

    SciTech Connect

    Hwang, Yong Pil; Jeong, Hye Gwang

    2008-12-15

    Phytoestrogens are polyphenolic non-steroidal plant compounds with estrogen-like biological activity. The phytoestrogen puerarin, the main isoflavone glycoside found in the root of Pueraria lobata, has been used for various medicinal purposes in traditional Chinese medicines for thousands of years. Recent studies have indicated that the estrogen receptor (ER), through interaction with p85, regulates phosphoinositide 3-kinase (PI3K) activity, revealing a physiologic, non-nuclear function of ER that may be relevant in cytoprotection. In this study, we demonstrate that the phytoestrogen puerarin inhibits tert-butyl hydroperoxide (t-BHP)-induced oxidative injury via an ER-dependent G{beta}1/PI3K/Akt and heme oxygenase-1 (HO-1) pathway. Pretreatment of Hepa1c1c7 and HepG2 cells with puerarin significantly reduced t-BHP-induced caspase-3 activation and subsequent cell death. Also, puerarin up-regulated HO-1 expression and this expression conferred cytoprotection against oxidative injury induced by t-BHP. Moreover, puerarin induced Nrf2 nuclear translocation, which is upstream of puerarin-induced HO-1 expression, and PI3K activation, a pathway that is involved in induced Nrf2 nuclear translocation, HO-1 expression and cytoprotection. Puerarin-induced up-regulation of HO-1 and cytoprotection against t-BHP were abolished by silencing Nrf2 expression with specific siRNA. Also, puerarin-mediated increases in PI3K activation and HO-1 induction were reversed by co-treatment with ICI 182,780 and pertussis toxin. Taken together, these results suggest that puerarin augments cellular antioxidant defense capacity through ER-dependent HO-1 induction via the G{beta}1/PI3K/Akt-Nrf2 signaling pathway, thereby protecting cells from oxidative stress.

  17. Novel Insights Into Hydrogen Sulfide–Mediated Cytoprotection

    PubMed Central

    Calvert, John W.; Coetzee, William A.

    2010-01-01

    Abstract Hydrogen sulfide (H2S) is a colorless, water soluble, flammable gas that has the characteristic smell of rotten eggs. Like other members of the gasotransmitter family (nitric oxide and carbon monoxide), H2S has traditionally been considered to be a highly toxic gas and environmental hazard. However, much like for nitric oxide and carbon monoxide, the initial negative perception of H2S has evolved with the discovery that H2S is produced enzymatically in mammals under normal conditions. As a result of this discovery, there has been a great deal of work to elucidate the physiological role of H2S. H2S is now recognized to be cytoprotective in various models of cellular injury. Specifically, it has been demonstrated that the acute administration of H2S, either prior to ischemia or at reperfusion, significantly ameliorates in vitro or in vivo myocardial and hepatic ischemia-reperfusion injury. These studies have also demonstrated a cardioprotective role for endogenous H2S. This review article summarizes the current body of evidence demonstrating the cytoprotective effects of H2S with an emphasis on the cardioprotective effects. This review also provides a detailed description of the current signaling mechanisms shown to be responsible for these cardioprotective actions. Antioxid. Redox Signal. 12, 1203–1217. PMID:19769484

  18. Implication of Mitochondrial Cytoprotection in Human Islet Isolation and Transplantation

    PubMed Central

    Wang, Yong; Mendoza-Elias, Joshua E.; Qi, Meirigeng; Harvat, Tricia A.; Ahn, Sang Joon; Lee, Dongyoung; Gutierrez, Diana; Jeon, Hyojin; Paushter, Daniel; Oberholzer, José

    2012-01-01

    Islet transplantation is a promising therapy for type 1 diabetes mellitus; however, success rates in achieving both short- and long-term insulin independence are not consistent, due in part to inconsistent islet quality and quantity caused by the complex nature and multistep process of islet isolation and transplantation. Since the introduction of the Edmonton Protocol in 2000, more attention has been placed on preserving mitochondrial function as increasing evidences suggest that impaired mitochondrial integrity can adversely affect clinical outcomes. Some recent studies have demonstrated that it is possible to achieve islet cytoprotection by maintaining mitochondrial function and subsequently to improve islet transplantation outcomes. However, the benefits of mitoprotection in many cases are controversial and the underlying mechanisms are unclear. This article summarizes the recent progress associated with mitochondrial cytoprotection in each step of the islet isolation and transplantation process, as well as islet potency and viability assays based on the measurement of mitochondrial integrity. In addition, we briefly discuss immunosuppression side effects on islet graft function and how transplant site selection affects islet engraftment and clinical outcomes. PMID:22611495

  19. A cytoprotective and degradable metal-polyphenol nanoshell for single-cell encapsulation.

    PubMed

    Park, Ji Hun; Kim, Kyunghwan; Lee, Juno; Choi, Ji Yu; Hong, Daewha; Yang, Sung Ho; Caruso, Frank; Lee, Younghoon; Choi, Insung S

    2014-11-10

    Single-cell encapsulation promises the cytoprotection of the encased cells against lethal stressors, reminiscent of the sporulation process in nature. However, the development of a cytocompatible method for chemically mimicking the germination process (i.e., shell degradation on-demand) has been elusive, despite the shell degradation being pivotal for the practical use of functional cells as well as for single cell-based biology. We report that an artificial shell, composed of tannic acid (TA) and Fe(III) , on individual Saccharomyces cerevisiae controllably degrades on-demand, while protecting the yeast from multiple external aggressors, including UV-C irradiation, lytic enzymes, and silver nanoparticles. Cell division is suppressed by the TA-Fe(III) shell, but restored fully upon shell degradation. The formation of a TA-Fe(III) shell would provide a versatile tool for achieving the chemical version of "sporulation and germination".

  20. Sargassum fusiforme polysaccharides activate antioxidant defense by promoting Nrf2-dependent cytoprotection and ameliorate stress insult during aging.

    PubMed

    Chen, Peichao; He, Dan; Zhang, Ya; Yang, Shanshan; Chen, Liujun; Wang, Shengqin; Zou, Huixi; Liao, Zhiyong; Zhang, Xu; Wu, Mingjiang

    2016-11-09

    Aging is a complex issue, which results in a progressive decline process in cellular protection and physiological functions. Illustrating the causes of aging and pharmaceutical interference with the aging process has been a pivotal issue for thousands of years. Sargassum fusiforme (S. fusiforme), a kind of brown alga, is also named the "longevity vegetable" as it is not only a kind of food, but also used as an herb in traditional Chinese Medicine for maintaining health and treatment of thyroid disease, cardiovascular disease and so on. But how S. fusiforme promotes longevity is vastly equivocal. We got clues from S. fusiforme polysaccharides, which exhibited antioxidant activity, but the underlying mechanisms remained unclear. In this study, we evaluated the antioxidant effect and the possible mechanisms that S. fusiforme polysaccharides have against d-galactose-induced aging and chronic aging. We selected the SFPS as the candidate for antioxidant defense evaluation, which is a type of S. fusiforme polysaccharide with strong free radical scavenging activity and non-toxicity. It revealed that the antioxidant defense of the d-galactose-induced mice was markedly recovered when they were intragastrically administrated with the SFPS. However, oxidative damage may not be the only cause of aging. We further evaluated the function of the SFPS in the chronic aging mice. Intriguingly, we even found an obvious aging phenotype in the middle aged male ICR mice, which showed a significant decline in Nrf2-dependent cytoprotection. When 9-month old male ICR mice were treated with the SFPS for 2 months or even 11 months to their mean survival age, experimental measurements showed that the SFPS significantly promoted the antioxidant defense and mitochondrial integrity during aging. Furthermore, we suggest that the SFPS promotes Nrf2-dependent cytoprotection by upregulating the nuclear Nrf2 translocation, which may be mediated by p21 and JNK dependent pathways. These results suggest

  1. 3D co-cultures of keratinocytes and melanocytes and cytoprotective effects on keratinocytes against reactive oxygen species by insect virus-derived protein microcrystals.

    PubMed

    Shimabukuro, Junji; Yamaoka, Ayako; Murata, Ken-Ichi; Kotani, Eiji; Hirano, Tomoko; Nakajima, Yumiko; Matsumoto, Goichi; Mori, Hajime

    2014-09-01

    Stable protein microcrystals called polyhedra are produced by certain insect viruses. Cytokines, such as fibroblast growth factors (FGFs), can be immobilized within polyhedra. Here, we investigated three-dimensional (3D) co-cultures of keratinocytes and melanocytes on collagen gel containing FGF-2 and FGF-7 polyhedra. Melanocytes were observed to reside at the base of the 3D cell culture and melanin was also typically observed in the lower layer. The 3D cell culture model with FGF-2 and FGF-7 polyhedra was a useful in vitro model of the epidermis due to effective melanogenesis, proliferation and differentiation of keratinocytes. FGF-7 polyhedra showed a potent cytoprotective effect when keratinocytes were treated with menadione, which is a generator of reactive oxygen species. The cytoprotective effect was activated by the inositol triphosphate kinase-Akt pathway leading to upregulation of the antioxidant enzymes superoxide dismutase and peroxiredoxin 6.

  2. Cytoprotection of human endothelial cells against oxidative stress by 1-[2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oyl]imidazole (CDDO-Im): application of systems biology to understand the mechanism of action.

    PubMed

    Wang, Xinyu; Bynum, James A; Stavchansky, Solomon; Bowman, Phillip D

    2014-07-05

    Cellular damage from oxidative stress, in particular following ischemic injury, occurs during heart attack, stroke, or traumatic injury, and is potentially reducible with appropriate drug treatment. We previously reported that caffeic acid phenethyl ester (CAPE), a plant-derived polyphenolic compound, protected human umbilical vein endothelial cells (HUVEC) from menadione-induced oxidative stress and that this cytoprotective effect was correlated with the capacity to induce heme oxygenase-1 (HMOX1) and its protein product, a phase II cytoprotective enzyme. To further improve this cytoprotective effect, we studied a synthetic triterpenoid, 1-[2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oyl]imidazole (CDDO-Im), which is known as a potent phase II enzyme inducer with antitumor and anti-inflammatory activities, and compared it to CAPE. CDDO-Im at 200nM provided more protection to HUVEC against oxidative stress than 20μM CAPE. We explored the mechanism of CDDO-Im cytoprotection with gene expression profiling and pathway analysis and compared to that of CAPE. In addition to potent up-regulation of HMOX1, heat shock proteins (HSP) were also found to be highly induced by CDDO-Im in HUVEC. Pathway analysis results showed that transcription factor Nrf2-mediated oxidative stress response was among the top canonical pathways commonly activated by both CDDO-Im and CAPE. Compared to CAPE, CDDO-Im up-regulated more HSP and some of them to a much higher extent. In addition, CDDO-Im treatment affected Nrf2 pathway more significantly. These findings may provide an explanation why CDDO-Im is a more potent cytoprotectant than CAPE against oxidative stress in HUVEC.

  3. Prohibitin confers cytoprotection against ISO-induced hypertrophy in H9c2 cells via attenuation of oxidative stress and modulation of Akt/Gsk-3β signaling.

    PubMed

    Chowdhury, Debabrata; Kumar, Dinesh; Bhadra, Utpal; Devi, Tangutur Anjana; Bhadra, Manika Pal

    2017-01-01

    Numerous hypertrophic stimuli, including β-adrenergic agonists such as isoproterenol (ISO), result in generation of reactive oxygen species (ROS) and alteration in the mitochondrial membrane potential (Δψ) leading to oxidative stress. This process is well associated with phosphorylation of thymoma viral proto-oncogene Akt (Ser473) and glycogen synthase kinase-3β (Gsk-3β) (Ser9), with resultant inactivation of Gsk-3β. In the present study, we found that the protective defensive role of prohibitin (PHB) against ISO-induced hypertrophic response in rat H9c2 cells is via attenuation of oxidative stress-dependent signaling pathways. The intracellular levels of mitochondrial membrane potential along with cellular ROS levels and mitochondrial superoxide generation were determined. In order to understand the regulation of Akt/Gsk-3β signaling pathway, we carried out immmunoblotting for key proteins of the pathway such as PTEN, PI3K, phosphorylated, and unphosphorylated forms of Akt, Gsk-3β, and immunofluorescence experiments of p-Gsk-3β. Enforced expression of PHB in ISO-treated H9c2 cells suppressed cellular ROS production with mitochondrial superoxide generation and enhanced the mitochondrial membrane potential resulting in suppression of oxidative stress which likely offered potent cellular protection, led to the availability of more healthy cells, and also, significant constitutive activation of Gsk-3β via inactivation of Akt was observed. Knockdown of PHB expression using PHB siRNA in control H9c2 cells reversed these effects. Overall, our results demonstrate that PHB confers cytoprotection against oxidative stress in ISO-induced hypertrophy and this process is associated with modulation of Akt/Gsk-3β signaling mechanisms as evident from our PHB overexpression and knockdown experiments.

  4. Induction of cyto-protective autophagy by paramontroseite VO2 nanocrystals

    NASA Astrophysics Data System (ADS)

    Zhou, Wei; Miao, Yanyan; Zhang, Yunjiao; Liu, Liang; Lin, Jun; Yang, James Y.; Xie, Yi; Wen, Longping

    2013-04-01

    A variety of inorganic nanomaterials have been shown to induce autophagy, a cellular degradation process critical for the maintenance of cellular homeostasis. The overwhelming majority of autophagic responses elicited by nanomaterials were detrimental to cell fate and contributed to increased cell death. A widely held view is that the inorganic nanoparticles, when encapsulated and trapped by autophagosomes, may compromise the normal autophagic process due to the inability of the cells to degrade these materials and thus they manifest a detrimental effect on the well-being of a cell. Here we show that, contrary to this notion, nano-sized paramontroseite VO2 nanocrystals (P-VO2) induced cyto-protective, rather than death-promoting, autophagy in cultured HeLa cells. P-VO2 also caused up-regulation of heme oxygenase-1 (HO-1), a cellular protein with a demonstrated role in protecting cells against death under stress situations. The autophagy inhibitor 3-methyladenine significantly inhibited HO-1 up-regulation and increased the rate of cell death in cells treated with P-VO2, while the HO-1 inhibitor protoporphyrin IX zinc (II) (ZnPP) enhanced the occurrence of cell death in the P-VO2-treated cells while having no effect on the autophagic response induced by P-VO2. On the other hand, Y2O3 nanocrystals, a control nanomaterial, induced death-promoting autophagy without affecting the level of expression of HO-1, and the pro-death effect of the autophagy induced by Y2O3. Our results represent the first report on a novel nanomaterial-induced cyto-protective autophagy, probably through up-regulation of HO-1, and may point to new possibilities for exploiting nanomaterial-induced autophagy for therapeutic applications.

  5. Autocrine expression of hepatocyte growth factor and its cytoprotective effect on hepatocyte poisoning

    PubMed Central

    He, Yong; Zhou, Jun; Dou, Ke-Feng; Chen, Yong; Yan, Qing-Guo; Li, Hai-Min

    2004-01-01

    AIM: To construct pEGFP-hepatocyte growth factor (HGF) expression vector, the to detect its expression in transfected human hepatocytes, and to investigate the influence of autocrine HGF expression on the proliferative potential and cytoprotective effects in human hepatocytes. METHODS: Human HGF cDNA was ligated to the pEGFP vector. Recombinant plasmid was transfected into human hepatocyte line QZG with liposome. Expression of HGF protein was observed by fluorescence microscopy and immunohistochemistry. Hepatic cells were collected 24, 48, and 72 h after transfection to detect the number of [3H]-TdR uptake in DNA. DNA synthesis was observed by using PCNA stain immunohistochemistry. Acute liver cell damage was induced by carbon tetrachloride. Cytoprotective effect was observed by examining the survival rate of hepatocytes and leakage of intracellular alanine transaminase (ALT) and potassium ions. RESULTS: HGF identification of pEGFP-HGF by enzyme digestion showed that HGF fragment was cloned into BamH I and Sal I sites of pEGFP-N3. Expression of GFP in transfected hepatocytes was observed with fluorescence microscopy. The [3H]-TdR uptake became 7 times as many as in the control group 96 h after transfection. After HGF transfection, the survival rate of hepatocytes poisoned by CCl4 significantly increased (83% vs 61%, P < 0.05), and the leakage of intracellular alanine transaminase and potassium ions decreased (586 nkat/L vs 1089 nkat/L, P < 0.01; and 5.59 mmol/L vs 6.02 mmol/L, P < 0.01 respectively). Culture of transfected hepatic cells promoted the proliferation of other non-transfected cells. CONCLUSION: Transfected HGF is expressed in hepatic cells and has the activity of promoting cell division and protecting hepatic cells against poisoning. PMID:15334679

  6. Targeted heat shock protein 72 for pulmonary cytoprotection.

    PubMed

    Parseghian, Missag H; Hobson, Stephen T; Richieri, Richard A

    2016-06-01

    Heat shock protein 72 (HSP72) is perhaps the most important member of the HSP70 family of proteins, given that it is induced in a wide variety of tissues and cells to combat stress, particularly oxidative stress. Here, we review independent observations of the critical role this protein plays as a pulmonary cytoprotectant and discuss the merits of developing HSP72 as a therapeutic for rapid delivery to cells and tissues after a traumatic event. We also discuss the fusion of HSP72 to a cell-penetrating single-chain Fv antibody fragment derived from mAb 3E10, referred to as Fv-HSP70. This fusion construct has been validated in vivo in a cerebral infarction model and is currently in testing as a clinical therapeutic to treat ischemic events and as a fieldable medical countermeasure to treat inhalation of toxicants caused by terrorist actions or industrial accidents.

  7. Mitochondrial fission - a drug target for cytoprotection or cytodestruction?

    PubMed

    Rosdah, Ayeshah A; K Holien, Jessica; Delbridge, Lea M D; Dusting, Gregory J; Lim, Shiang Y

    2016-06-01

    Mitochondria are morphologically dynamic organelles constantly undergoing processes of fission and fusion that maintain integrity and bioenergetics of the organelle: these processes are vital for cell survival. Disruption in the balance of mitochondrial fusion and fission is thought to play a role in several pathological conditions including ischemic heart disease. Proteins involved in regulating the processes of mitochondrial fusion and fission are therefore potential targets for pharmacological therapies. Mdivi-1 is a small molecule inhibitor of the mitochondrial fission protein Drp1. Inhibiting mitochondrial fission with Mdivi-1 has proven cytoprotective benefits in several cell types involved in a wide array of cardiovascular injury models. On the other hand, Mdivi-1 can also exert antiproliferative and cytotoxic effects, particularly in hyperproliferative cells. In this review, we discuss these divergent effects of Mdivi-1 on cell survival, as well as the potential and limitations of Mdivi-1 as a therapeutic agent.

  8. Thiosulfate Mediates Cytoprotective Effects of Hydrogen Sulfide Against Neuronal Ischemia.

    PubMed

    Marutani, Eizo; Yamada, Marina; Ida, Tomoaki; Tokuda, Kentaro; Ikeda, Kohei; Kai, Shinichi; Shirozu, Kazuhiro; Hayashida, Kei; Kosugi, Shizuko; Hanaoka, Kenjiro; Kaneki, Masao; Akaike, Takaaki; Ichinose, Fumito

    2015-11-06

    Hydrogen sulfide (H2S) exhibits protective effects in various disease models including cerebral ischemia-reperfusion (I/R) injury. Nonetheless, mechanisms and identity of molecules responsible for neuroprotective effects of H2S remain incompletely defined. In the current study, we observed that thiosulfate, an oxidation product of H2S, mediates protective effects of an H2S donor compound sodium sulfide (Na2S) against neuronal I/R injury. We observed that thiosulfate in cell culture medium is not only required but also sufficient to mediate cytoprotective effects of Na2S against oxygen glucose deprivation and reoxygenation of human neuroblastoma cell line (SH-SY5Y) and murine primary cortical neurons. Systemic administration of sodium thiosulfate (STS) improved survival and neurological function of mice subjected to global cerebral I/R injury. Beneficial effects of STS, as well as Na2S, were associated with marked increase of thiosulfate, but not H2S, in plasma and brain tissues. These results suggest that thiosulfate is a circulating "carrier" molecule of beneficial effects of H2S. Protective effects of thiosulfate were associated with inhibition of caspase-3 activity by persulfidation at Cys163 in caspase-3. We discovered that an SLC13 family protein, sodium sulfate cotransporter 2 (SLC13A4, NaS-2), facilitates transport of thiosulfate, but not sulfide, across the cell membrane, regulating intracellular concentrations and thus mediating cytoprotective effects of Na2S and STS. The protective effects of H2S are mediated by thiosulfate that is transported across cell membrane by NaS-2 and exerts antiapoptotic effects via persulfidation of caspase-3. Given the established safety track record, thiosulfate may be therapeutic against ischemic brain injury. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  9. Formation and Biological Targets of Quinones: Cytotoxic versus Cytoprotective Effects

    PubMed Central

    2016-01-01

    Quinones represent a class of toxicological intermediates, which can create a variety of hazardous effects in vivo including, acute cytotoxicity, immunotoxicity, and carcinogenesis. In contrast, quinones can induce cytoprotection through the induction of detoxification enzymes, anti-inflammatory activities, and modification of redox status. The mechanisms by which quinones cause these effects can be quite complex. The various biological targets of quinones depend on their rate and site of formation and their reactivity. Quinones are formed through a variety of mechanisms from simple oxidation of catechols/hydroquinones catalyzed by a variety of oxidative enzymes and metal ions to more complex mechanisms involving initial P450-catalyzed hydroxylation reactions followed by two-electron oxidation. Quinones are Michael acceptors, and modification of cellular processes could occur through alkylation of crucial cellular proteins and/or DNA. Alternatively, quinones are highly redox active molecules which can redox cycle with their semiquinone radical anions leading to the formation of reactive oxygen species (ROS) including superoxide, hydrogen peroxide, and ultimately the hydroxyl radical. Production of ROS can alter redox balance within cells through the formation of oxidized cellular macromolecules including lipids, proteins, and DNA. This perspective explores the varied biological targets of quinones including GSH, NADPH, protein sulfhydryls [heat shock proteins, P450s, cyclooxygenase-2 (COX-2), glutathione S-transferase (GST), NAD(P)H:quinone oxidoreductase 1, (NQO1), kelch-like ECH-associated protein 1 (Keap1), IκB kinase (IKK), and arylhydrocarbon receptor (AhR)], and DNA. The evidence strongly suggests that the numerous mechanisms of quinone modulations (i.e., alkylation versus oxidative stress) can be correlated with the known pathology/cytoprotection of the parent compound(s) that is best described by an inverse U-shaped dose–response curve. PMID:27617882

  10. Long-lasting cytoprotection after pentadecapeptide BPC 157, ranitidine, sucralfate or cholestyramine application in reflux oesophagitis in rats.

    PubMed

    Sikiric, P; Jadrijevic, S; Seiwerth, S; Sosa, T; Deskovic, S; Perovic, D; Aralica, G; Grabarevic, Z; Rucman, R; Petek, M; Jagic, V; Turkovic, B; Ziger, T; Rotkvic, I; Mise, S; Zoricic, I; Sebecic, B; Patrlj, L; Kocman, B; Sarlija, M; Mikus, D; Separovic, J; Hanzevacki, M; Gjurasin, M; Miklic, P

    1999-12-01

    Recently, the effectiveness of pentadecapeptide BPC 157 and other anti-ulcer agents, called 'direct cytoprotection', was evidenced in totally gastrectomized rats duodenum challenged with cysteamine 24 h after surgery, and sacrificed 24 h after ulcerogen application. The further focus was on the possibility that this effect could be seen over a more prolonged period (1, 2, 4 weeks), and in other parts of the gastrointestinal tract (i.e. oesophagus). After the removal of the stomach, the oesophagus and jejunum were joined by a termino-lateral anastomosis. The animals were euthanized 7, 14 or 28 d after surgery, when oesophagitis was blindly assessed both macroscopically (percentage of ulcerations areas) and microscopically (percentage of areas of ulcers, regeneration and hyperplasia; number of inflammatory cells - polymorphonuclear and mononuclear). Starting 24 h after surgery, the medication was continuously given in the drinking water, in a volume of 12.5 mL/rat daily, until euthanasia at the end of the observation period, i.e. 7, 14, 28 d following surgery. Based on previous experiments, the doses of agents were daily calculated per kg b.w. as follows: BPC 157 125 mg or 125 ng, cholestyramine 2.5 mg, ranitidine 125 mg, sucralfate 725 mg, whereas controls received 72.5 mL x kg(-1) water. In support of these initial findings, and considering gastrectomized acid-free rats as an ideal model for long-term cytoprotective studies as well, pentadecapeptide BPC 157 markedly attenuated termino-lateral oesophagojejunal anastomosis-reflux oesophagitis also over a quite prolonged period. This efficacy was only partly shared by other anti-ulcer agents. After 1-week-old oesophagitis (microscopical assessment), but not after 2 or 4 weeks, less damaged mucosa was noted in rats drinking ranitidine or sucralfate compared to controls. Similar effectiveness was noted for cholestyramine. The obtained results were supported also by inflammatory cell assessment. Compared with control

  11. Chemical sporulation and germination: cytoprotective nanocoating of individual mammalian cells with a degradable tannic acid-FeIII complex.

    PubMed

    Lee, Juno; Cho, Hyeoncheol; Choi, Jinsu; Kim, Doyeon; Hong, Daewha; Park, Ji Hun; Yang, Sung Ho; Choi, Insung S

    2015-12-07

    Individual mammalian cells were coated with cytoprotective and degradable films by cytocompatible processes maintaining the cell viability. Three types of mammalian cells (HeLa, NIH 3T3, and Jurkat cells) were coated with a metal-organic complex of tannic acid (TA) and ferric ion, and the TA-Fe(III) nanocoat effectively protected the coated mammalian cells against UV-C irradiation and a toxic compound. More importantly, the cell proliferation was controlled by programmed formation and degradation of the TA-Fe(III) nanocoat, mimicking the sporulation and germination processes found in nature.

  12. New cell-signaling pathways for controlling cytomegalovirus replication.

    PubMed

    Roy, S; Arav-Boger, R

    2014-06-01

    Cytomegalovirus (CMV) is increasingly recognized as an accomplished modulator of cell-signaling pathways, both directly via interaction between viral and cellular proteins, and indirectly by activating metabolic/energy states of infected cells. Viral genes, as well as captured cellular genes, enable CMV to modify these pathways upon binding to cellular receptors, up until generation of virus progeny. Deregulation of cell-signaling pathways appears to be a well-developed tightly balanced virus strategy to achieve the desired consequences in each infected cell type. Importantly and perhaps surprisingly, identification of new signaling pathways in cancer cells positioned CMV as a sophisticated user and abuser of many such pathways, creating opportunities to develop novel therapeutic strategies for inhibiting CMV replication (in addition to standard of care CMV DNA polymerase inhibitors). Advances in genomics and proteomics allow the identification of CMV products interacting with the cellular machinery. Ultimately, clinical implementation of candidate drugs capable of disrupting the delicate balance between CMV and cell-signaling will depend on the specificity and selectivity index of newly identified targets.

  13. Advanced Sensors and Controls for Building Applications: Market Assessment and Potential R&D Pathways

    SciTech Connect

    Brambley, M. R.; Haves, P.; McDonald, S. C.; Torcellini, P.; Hansen, D.; Holmberg, D. R.; Roth, K. W.

    2005-04-01

    This document provides a market assessment of existing building sensors and controls and presents a range of technology pathways (R&D options) for pursuing advanced sensors and building control strategies.

  14. Cytoprotective nanoparticles by conjugation of a polyhis tagged annexin V to a nanoparticle drug

    NASA Astrophysics Data System (ADS)

    Chen, Howard H.; Yuan, Hushan; Cho, Hoonsung; Sosnovik, David E.; Josephson, Lee

    2015-01-01

    We synthesized a cytoprotective magnetic nanoparticle by reacting a maleimide functionalized Feraheme (FH) with a disulfide linked dimer of a polyhis tagged annexin V. Following reductive cleavage of disulfide, the resulting annexin-nanoparticle (diameter = 28.0 +/- 2.0 nm by laser light scattering, 7.6 annexin's/nanoparticle) was cytoprotective to cells subjected to plasma membrane disrupting chemotherapeutic or mechanical stresses, and significantly more protective than the starting annexin V. Annexin-nanoparticles provide an approach to the design of nanomaterials which antagonize the plasma membrane permeability characteristic of necrosis and which may have applications as cytoprotective agents.

  15. Cytoprotective nanoparticles by conjugation of a polyhis tagged annexin V to a nanoparticle drug.

    PubMed

    Chen, Howard H; Yuan, Hushan; Cho, Hoonsung; Sosnovik, David E; Josephson, Lee

    2015-02-14

    We synthesized a cytoprotective magnetic nanoparticle by reacting a maleimide functionalized Feraheme (FH) with a disulfide linked dimer of a polyhis tagged annexin V. Following reductive cleavage of disulfide, the resulting annexin-nanoparticle (diameter = 28.0 ± 2.0 nm by laser light scattering, 7.6 annexin's/nanoparticle) was cytoprotective to cells subjected to plasma membrane disrupting chemotherapeutic or mechanical stresses, and significantly more protective than the starting annexin V. Annexin-nanoparticles provide an approach to the design of nanomaterials which antagonize the plasma membrane permeability characteristic of necrosis and which may have applications as cytoprotective agents.

  16. Molecular evolution of multiple-level control of heme biosynthesis pathway in animal kingdom.

    PubMed

    Tzou, Wen-Shyong; Chu, Ying; Lin, Tzung-Yi; Hu, Chin-Hwa; Pai, Tun-Wen; Liu, Hsin-Fu; Lin, Han-Jia; Cases, Ildeofonso; Rojas, Ana; Sanchez, Mayka; You, Zong-Ye; Hsu, Ming-Wei

    2014-01-01

    Adaptation of enzymes in a metabolic pathway can occur not only through changes in amino acid sequences but also through variations in transcriptional activation, mRNA splicing and mRNA translation. The heme biosynthesis pathway, a linear pathway comprised of eight consecutive enzymes in animals, provides researchers with ample information for multiple types of evolutionary analyses performed with respect to the position of each enzyme in the pathway. Through bioinformatics analysis, we found that the protein-coding sequences of all enzymes in this pathway are under strong purifying selection, from cnidarians to mammals. However, loose evolutionary constraints are observed for enzymes in which self-catalysis occurs. Through comparative genomics, we found that in animals, the first intron of the enzyme-encoding genes has been co-opted for transcriptional activation of the genes in this pathway. Organisms sense the cellular content of iron, and through iron-responsive elements in the 5' untranslated regions of mRNAs and the intron-exon boundary regions of pathway genes, translational inhibition and exon choice in enzymes may be enabled, respectively. Pathway product (heme)-mediated negative feedback control can affect the transport of pathway enzymes into the mitochondria as well as the ubiquitin-mediated stability of enzymes. Remarkably, the positions of these controls on pathway activity are not ubiquitous but are biased towards the enzymes in the upstream portion of the pathway. We revealed that multiple-level controls on the activity of the heme biosynthesis pathway depend on the linear depth of the enzymes in the pathway, indicating a new strategy for discovering the molecular constraints that shape the evolution of a metabolic pathway.

  17. Cytoprotective role of autophagy during paclitaxel-induced apoptosis in Saos-2 osteosarcoma cells.

    PubMed

    Kim, Hyeon Jun; Lee, Seung Gee; Kim, Yoon-Jae; Park, Ji-Eun; Lee, Kyu Yeol; Yoo, Young Hyun; Kim, Jong-Min

    2013-06-01

    Osteosarcoma (OS) is the most common primary malignant bone cancer in children and adolescents. Although paclitaxel (PCX) has been considered one of the most important cancer chemotherapeutic drugs, the current protocols for OS treatment do not incorporate this agent. Therefore, the purpose of this study was to evaluate the induction of cell death in OS cells after exposure to PCX, to identify the cell death mechanism(s) activated by PCX and to investigate whether autophagy is associated with PCX-induced apoptosis. The results of the present study confirmed that exposure to low PCX concentrations can induce apoptotic cell death in Saos-2 cells; furthermore, caspase-3 activation, PARP degradation and XIAP downregulation were observed in combination with PCX-induced apoptosis. The potential involvement of mitochondrial events (intrinsic apoptotic pathway) in PCX-induced apoptosis in OS cells was verified by the alteration (depolarization) of mitochondrial membrane potential. In addition, pretreatment with 3-methyladenine (3-MA), a specific inhibitor of autophagy, significantly increased PCX-induced apoptotic cell death in Saos-2 cells. The augmentation of PCX-induced apoptosis by 3-MA was accompanied by increase in the cytochrome c release from the mitochondria, caspase-3 activity and XIAP downregulation, which suggests that inhibiting autophagy further stimulates the PCX-induced mitochondrion-related (intrinsic) apoptotic pathway by provoking caspase-3 activation. Thus, autophagy observed during PCX-induced apoptosis in Saos-2 OS cells represents the role of cytoprotection in cellular homeostatic processes. In conclusion, the results of this study revealed that PCX exposure effectively induces OS cell death by apoptosis associated with the mitochondrial-mediated caspase-dependent pathway. PCX can increase autophagic activity and suppressing autophagy enhances PCX-induced apoptosis in OS cells. Therefore, it is suggested that combination treatment involving low

  18. Hydralazine inhibits rapid acrolein-induced protein oligomerization: role of aldehyde scavenging and adduct trapping in cross-link blocking and cytoprotection.

    PubMed

    Burcham, Philip C; Pyke, Simon M

    2006-03-01

    Hydralazine strongly suppresses the toxicity of acrolein, a reactive aldehyde that contributes to numerous health disorders. At least two mechanisms may underlie the cytoprotection, both of which involve the nucleophilic hydrazine possessed by hydralazine. Under the simplest scenario, hydralazine directly scavenges free acrolein, decreasing intracellular acrolein availability and thereby suppressing macromolecular adduction. In a second "adduct-trapping" mechanism, the drug forms hydrazones with acrolein-derived Michael adducts in cell proteins, preventing secondary reactions of adducted proteins that may trigger cell death. To identify the most important mechanism, we explored these two pathways in mouse hepatocytes poisoned with the acrolein precursor allyl alcohol. Intense concentration-dependent adduct-trapping in cell proteins accompanied the suppression of toxicity by hydralazine. However, protective concentrations of hydralazine did not alter extracellular free acrolein levels, cellular glutathione loss, or protein carbonylation, suggesting that the cytoprotection is not due to minimization of intracellular acrolein availability. To explore ways whereby adduct-trapping might confer cytoprotection, the effect of hydralazine on acrolein-induced protein cross-linking was examined. Using bovine pancreas ribonuclease A as a model protein, acrolein caused rapid time- and concentration-dependent cross-linking, with dimerized protein detectable within 45 min of commencing protein modification. Lysine adduction in monomeric protein preceded the appearance of oligomers, whereas reductive methylation of protein amine groups abolished both adduction and oligomerization. Hydralazine inhibited cross-linking if added 30 min after commencing acrolein exposure but was ineffective if added after a 90-min delay. Adduct-trapping closely accompanied the inhibition of cross-linking by hydralazine. These findings suggest that cross-link blocking may contribute to hydralazine

  19. Modulation of transglutaminase 2 activity in H9c2 cells by PKC and PKA signalling: a role for transglutaminase 2 in cytoprotection

    PubMed Central

    Almami, Ibtesam; Dickenson, John M; Hargreaves, Alan J; Bonner, Philip L R

    2014-01-01

    BACKGROUND AND PURPOSE Tissue transglutaminase (TG2) has been shown to mediate cell survival in many cell types. In this study, we investigated whether the role of TG2 in cytoprotection was mediated by the activation of PKA and PKC in cardiomyocyte-like H9c2 cells. EXPERIMENTAL APPROACH H9c2 cells were extracted following stimulation with phorbol-12-myristate-13-acetate (PMA) and forskolin. Transglutaminase activity was determined using an amine incorporating and a protein crosslinking assay. The presence of TG isoforms (TG1, 2, 3) was determined using Western blot analysis. The role of TG2 in PMA- and forskolin-induced cytoprotection was investigated by monitoring H2O2-induced oxidative stress in H9c2 cells. KEY RESULTS Western blotting showed TG2 >> TG1 protein expression but no detectable TG3. The amine incorporating activity of TG2 in H9c2 cells increased in a time and concentration-dependent manner following stimulation with PMA and forskolin. PMA and forskolin-induced TG2 activity was blocked by PKC (Ro 31-8220) and PKA (KT 5720 and Rp-8-Cl-cAMPS) inhibitors respectively. The PMA- and forskolin-induced increases in TG2 activity were attenuated by the TG2 inhibitors Z-DON and R283. Immunocytochemistry revealed TG2-mediated biotin-X-cadaverine incorporation into proteins and proteomic analysis identified known (β-tubulin) and novel (α-actinin) protein substrates for TG2. Pretreatment with PMA and forskolin reversed H2O2-induced decrease in MTT reduction and release of LDH. TG2 inhibitors R283 and Z-DON blocked PMA- and forskolin-induced cytoprotection. CONCLUSIONS AND IMPLICATIONS TG2 activity was stimulated via PKA- and PKC-dependent signalling pathways in H9c2 cells These results suggest a role for TG2 in cytoprotection induced by these kinases. PMID:24821315

  20. Asparaginase induces apoptosis and cytoprotective autophagy in chronic myeloid leukemia cells.

    PubMed

    Song, Ping; Ye, Li; Fan, Jiajun; Li, Yubin; Zeng, Xian; Wang, Ziyu; Wang, Shaofei; Zhang, Guoping; Yang, Ping; Cao, Zhonglian; Ju, Dianwen

    2015-02-28

    The antitumor enzyme asparaginase, which targets essential amino acid L-asparagine and catalyzes it to L-aspartic acid and ammonia, has been used for years in the treatment of acute lymphoblastic leukemia (ALL), subtypes of myeloid leukemia and T-cell lymphomas, whereas the anti-chronic myeloid leukemia (CML) effect of asparaginase and its underlying mechanism has not been completely elucidated. We have shown here that asparaginase induced significant growth inhibition and apoptosis in K562 and KU812 cells. Apart from induction of apoptosis, we reported for the first time that asparaginase induced autophagic response in K562 and KU812 cells as evidenced by the formation of autophagosome, microtubule-associated protein light chain 3 (LC3)-positive autophagy-like vacuoles, and the upregulation of LC3-II. Further study suggested that the Akt/mTOR (mammalian target of rapamycin) and Erk (extracellular signal-regulated kinase) signaling pathway were involved in asparaginase-induced autophagy in K562 cells. Moreover, blocking autophagy using pharmacological inhibitors LY294002, chloroquine (CQ) and quinacrine (QN) enhanced asparaginase-induced cell death and apoptosis, indicating the cytoprotective role of autophagy in asparaginase-treated K562 and KU812 cells. Together, these findings provide a rationale that combination of asparaginase anticancer activity and autophagic inhibition might be a promising new therapeutic strategy for CML.

  1. EGFR tyrosine kinase inhibitors activate autophagy as a cytoprotective response in human lung cancer cells.

    PubMed

    Han, Weidong; Pan, Hongming; Chen, Yan; Sun, Jie; Wang, Yanshan; Li, Jing; Ge, Weiting; Feng, Lifeng; Lin, Xiaoying; Wang, Xiaojia; Wang, Xian; Jin, Hongchuan

    2011-01-01

    Epidermal growth factor receptor tyrosine kinase inhibitors gefitinib and erlotinib have been widely used in patients with non-small-cell lung cancer. Unfortunately, the efficacy of EGFR-TKIs is limited because of natural and acquired resistance. As a novel cytoprotective mechanism for tumor cell to survive under unfavorable conditions, autophagy has been proposed to play a role in drug resistance of tumor cells. Whether autophagy can be activated by gefitinib or erlotinib and thereby impair the sensitivity of targeted therapy to lung cancer cells remains unknown. Here, we first report that gefitinib or erlotinib can induce a high level of autophagy, which was accompanied by the inhibition of the PI3K/Akt/mTOR signaling pathway. Moreover, cytotoxicity induced by gefitinib or erlotinib was greatly enhanced after autophagy inhibition by the pharmacological inhibitor chloroquine (CQ) and siRNAs targeting ATG5 and ATG7, the most important components for the formation of autophagosome. Interestingly, EGFR-TKIs can still induce cell autophagy even after EGFR expression was reduced by EGFR specific siRNAs. In conclusion, we found that autophagy can be activated by EGFR-TKIs in lung cancer cells and inhibition of autophagy augmented the growth inhibitory effect of EGFR-TKIs. Autophagy inhibition thus represents a promising approach to improve the efficacy of EGFR-TKIs in the treatment of patients with advanced non-small-cell lung cancer.

  2. Cytoprotective effects of phenolic acids on methylglyoxal-induced apoptosis in Neuro-2A cells.

    PubMed

    Huang, Shang-Ming; Chuang, Hong-Chih; Wu, Chi-Hao; Yen, Gow-Chin

    2008-08-01

    In the process of glycation, methylglyoxal is a reactive dicarbonyl compound physiologically generated as an intermediate of glycolysis, and is found in high levels in blood or tissue of diabetic models. Biological glycation has been commonly implicated in the development of diabetic microvascular complications of neuropathy. Increasing evidence suggests that neuronal cell cycle regulatory failure followed by apoptosis is an important mechanism in the development of diabetic neuropathy complication. Naturally occurring antioxidants, especially phenolic acids have been recommended as the major bioactive compounds to prevent chronic diseases and promote health benefits. The objective of this study was to investigate the inhibitory abilities of phenolic acids (chlorogenic acid, syringic acid and vanillic acid) on methylglyoxal-induced mouse Neuro-2A neuroblastoma (Neuro-2A) cell apoptosis in the progression of diabetic neuropathy. The data indicated that methylglyoxal induced mouse Neuro-2A neuroblastoma (Neuro-2A) cell apoptosis via alternation of mitochondria membrane potential and Bax/Bcl-2 ratio, activation of caspase-3, and cleavage of poly (ADP-ribose) polymerase. Furthermore, the results demonstrated that activation of mitogen-activated protein kinase signal pathways (JNK and p38) participated in the methylglyoxal-induced Neuro-2A cell apoptosis process. Treatment of Neuro-2A cells with phenolic acids markedly suppresses cell apoptosis induced by methylglyoxal, suggesting that phenolic acids possess cytoprotective ability in the prevention of diabetic neuropathy complication.

  3. Signaling Pathways That Control mRNA Turnover

    PubMed Central

    Thapar, Roopa; Denmon, Andria P.

    2013-01-01

    Cells regulate their genomes mainly at the level of transcription and at the level of mRNA decay. While regulation at the level of transcription is clearly important, the regulation of mRNA turnover by signaling networks is essential for a rapid response to external stimuli. Signaling pathways result in posttranslational modification of RNA binding proteins by phosphorylation, ubiquitination, methylation, acetylation etc. These modifications are important for rapid remodeling of dynamic ribonucleoprotein complexes and triggering mRNA decay. Understanding how these posttranslational modifications alter gene expression is therefore a fundamental question in biology. In this review we highlight recent findings on how signaling pathways and cell cycle checkpoints involving phosphorylation, ubiquitination, and arginine methylation affect mRNA turnover. PMID:23602935

  4. Trophic Status Controls Mercury Methylation Pathways in Northern Peats

    NASA Astrophysics Data System (ADS)

    Hines, M. E.; Zhang, L.; Barkay, T.; Krabbenhoft, D. P.; Schaefer, J.; Hu, H.; Sidelinger, W.; Liu, X.; Wang, Y.

    2015-12-01

    Methyl mercury (MeHg) can be produced by a variety of microbes including syntrophs, methanogens, acetogens, and fermenters, besides sulfate (SO42-, SRB) and iron- reducing bacteria. Many freshwater wetlands are deficient in electron acceptors that support the traditional respiratory pathways of methylation, yet they accumulate high levels of MeHg. To investigate methylation in these wetlands and to connect these pathways with vegetation and microbial communities, incubation experiments were conducted using peats from 26 sites in Alaska. The sites were clustered using multiple factor analysis based on pH, temp, CH4 and volatile fatty acids production rates, and surface vegetation composition. Three clusters were generated and corresponded to three trophic levels that were manifested by three pH levels (3.5, 4.5, and 5). Hg methylation activity in laboratory incubations was determined using the short-lived radioisotope 197Hg. In the low pH, Sphagnum-dominated cluster, methylation rates were less than 1% day-1 and likely conducted by primary fermenters. Conversely, the high pH trophic cluster dominated by Carex aquatilis and active syntrophy exhibited Hg methylation rates as high as 12% day-1. In intermediate sites, rich in Sphagnum magellanicum with less Carex, a gradient in syntrophy and Hg methylation paths was observed. Amendments with process-stimulators and inhibitors revealed no evidence of SO42- reduction, but suggested that SRB, metabolizing either syntrophically with methanogens and/or by fermentation, likely methylated Hg. While on going metatranscriptomics studies are required to verify the role of syntrophs, fermenters, and methanogens as methylators, these results revealed that Hg methylation pathways change greatly along trophic gradients with a dominance of respiratory pathways in mineral-rich sites, syntrophy dominance in intermediate sites, and fermentation dominance in nutrient-poor sites.

  5. Cytoprotective effect of imatinib mesylate in non-BCR-ABL-expressing cells along with autophagosome formation

    SciTech Connect

    Ohtomo, Tadashi; Miyazawa, Keisuke; Naito, Munekazu; Moriya, Shota; Kuroda, Masahiko; Itoh, Masahiro; Tomoda, Akio

    2010-01-01

    Treatment with imatinib mesylate (IM) results in an increased viable cell number of non-BCR-ABL-expressing cell lines by inhibiting spontaneous apoptosis. Electron microscopy revealed an increase of autophagosomes in response to IM. IM attenuated the cytotoxic effect of cytosine arabinoside, as well as inhibiting cell death with serum-deprived culture. Cytoprotection with autophagosome formation by IM was observed in various leukemia and cancer cell lines as well as normal murine embryonic fibroblasts (MEFs). Complete inhibition of autophagy by knockdown of atg5 in the Tet-off atg5{sup -/-} MEF system attenuated the cytoprotective effect of IM, indicating that the effect is partially dependent on autophagy. However, cytoprotection by IM was not mediated through suppression of ROS production via mitophagy, ER stress via ribophagy, or proapoptotic function of ABL kinase. Although the target tyrosine kinase(s) of IM remains unclear, our data provide novel therapeutic possibilities of using IM for cytoprotection.

  6. Sensitive cells: enabling tools for static and dynamic control of microbial metabolic pathways.

    PubMed

    Cress, Brady F; Trantas, Emmanouil A; Ververidis, Filippos; Linhardt, Robert J; Koffas, Mattheos Ag

    2015-12-01

    Natural metabolic pathways are dynamically regulated at the transcriptional, translational, and protein levels. Despite this, traditional pathway engineering has relied on static control strategies to engender changes in metabolism, most likely due to ease of implementation and perceived predictability of design outcome. Increasingly in recent years, however, metabolic engineers have drawn inspiration from natural systems and have begun to harness dynamically controlled regulatory machinery to improve design of engineered microorganisms for production of specialty and commodity chemicals. Here, we review recent enabling technologies for engineering static control over pathway expression levels, and we discuss state-of-the-art dynamic control strategies that have yielded improved outcomes in the field of microbial metabolic engineering. Furthermore, we emphasize design of a novel class of genetically encoded controllers that will facilitate automatic, transient tuning of synthetic and endogenous pathways.

  7. Chemical sporulation and germination: cytoprotective nanocoating of individual mammalian cells with a degradable tannic acid-FeIII complex

    NASA Astrophysics Data System (ADS)

    Lee, Juno; Cho, Hyeoncheol; Choi, Jinsu; Kim, Doyeon; Hong, Daewha; Park, Ji Hun; Yang, Sung Ho; Choi, Insung S.

    2015-11-01

    Individual mammalian cells were coated with cytoprotective and degradable films by cytocompatible processes maintaining the cell viability. Three types of mammalian cells (HeLa, NIH 3T3, and Jurkat cells) were coated with a metal-organic complex of tannic acid (TA) and ferric ion, and the TA-FeIII nanocoat effectively protected the coated mammalian cells against UV-C irradiation and a toxic compound. More importantly, the cell proliferation was controlled by programmed formation and degradation of the TA-FeIII nanocoat, mimicking the sporulation and germination processes found in nature.Individual mammalian cells were coated with cytoprotective and degradable films by cytocompatible processes maintaining the cell viability. Three types of mammalian cells (HeLa, NIH 3T3, and Jurkat cells) were coated with a metal-organic complex of tannic acid (TA) and ferric ion, and the TA-FeIII nanocoat effectively protected the coated mammalian cells against UV-C irradiation and a toxic compound. More importantly, the cell proliferation was controlled by programmed formation and degradation of the TA-FeIII nanocoat, mimicking the sporulation and germination processes found in nature. Electronic supplementary information (ESI) available: Experimental details, LSCM images, and SEM and TEM images. See DOI: 10.1039/c5nr05573c

  8. Evaluation of the antioxidant capacity, furan compounds and cytoprotective/cytotoxic effects upon Caco-2 cells of commercial Colombian coffee.

    PubMed

    Bedoya-Ramírez, Daniel; Cilla, Antonio; Contreras-Calderón, José; Alegría-Torán, Amparo

    2017-03-15

    Antioxidant capacity (AC), total phenolics (TPs), furan compounds (HMF and furfural F) and cytoprotective/cytotoxic effects upon Caco-2 cells (MTT, cell cycle and reactive oxygen species (ROS)) were evaluated in Colombian coffee (2 ground and 4 soluble samples). The AC (ABTS and FRAP), TPs and HMF ranged between 124-722, 95-802μmoles Trolox/g, 21-100mg gallic acid/g and 69-2900mg/kg, respectively. Pretreatment of cells for 24h with lyophilized coffee infusions at the highest dose without cytotoxic effects (500μg/mL) significantly prevented the decrease in cell viability compared to control stress with H2O2 (5mM/2h), recovering viability to values between 34% and 45% and restoring the control values without stress induction in the G1 phase of cell cycle. After exposure to stress, four extracts decreased ROS values significantly to 22.5-24.9%. The coffee samples exerted a cytoprotective effect against oxidative stress, with improvement in cell viability and a reduction of intracellular ROS.

  9. Probing the Pathways and Interactions Controlling Crystallization by Particle Attachment

    NASA Astrophysics Data System (ADS)

    De Yoreo, J. J.; Li, D.; Chun, J.; Schenter, G.; Mundy, C.; Rosso, K. M.

    2016-12-01

    Crystallization by particle attachment appears to be a widespread mechanism of mineralization. Yet many long-standing questions surrounding nucleation and assembly of precursor particles remain unanswered, due in part to a lack of tools to probe mineralization dynamics with adequate spatial and temporal resolution. Here we report results of liquid phase TEM studies of nucleation and particle assembly in a number of mineral systems. We interpret the results within a framework that considers the impact of both the complexity of free energy landscapes and kinetic factors associated with high supersaturation or slow dynamics. In the calcium carbonate system, the need for high supersturations to overcome the high barrier to nucleation of calcite leads to simultaneous occurrence of multiple pathways, including direct formation of all the common ploymorphs, as well as two-step pathways through which initial precursors, particularly ACC, undergo a direct transformation to a more stable phase. Introduction of highly charged polymers that bind calcium inhibits nucleation, but directs the pathway to a metastable amorphous phase that no longer transforms to more stable polymorphs. Experiments in the iron oxide and oxyhydroxide systems show that, when high supersaturations lead to nucleation of many nanoprticles, further growth occurs through a combination of particle aggregation events and Ostwald ripening. In some cases, aggregation occurs only through oriented attachment on lattice matched faces, leading to single crystals with complex topologies and internal twin boundaries, while in others aggregation results initially in poor co-alignment, but over time the particles undergo atomic rearrangements to achieve a single crystal structure. AFM-based measurements of forces between phyllosilicate surfaces reveal the importance of long-range dispersion interactions in driving alignment, as well as the impact of electrolyte concentration and temperature on the competition of those

  10. Control of the innate immune response by the mevalonate pathway

    PubMed Central

    Akula, Murali K.; Shi, Man; Jiang, Zhaozhao; Foster, Celia E.; Miao, David; Li, Annie S.; Zhang, Xiaoman; Gavin, Ruth M.; Forde, Sorcha D.; Germain, Gail; Carpenter, Susan; Rosadini, Charles V.; Gritsman, Kira; Chae, Jae Jin; Hampton, Randolph; Silverman, Neal; Gravallese, Ellen M.; Kagan, Jonathan C.; Fitzgerald, Katherine A.; Kastner, Daniel L.; Golenbock, Douglas T.; Bergo, Martin O.; Wang, Donghai

    2016-01-01

    Deficiency of mevalonate kinase (MVK) causes systemic inflammation. However, the molecular mechanisms linking the mevalonate pathway to inflammation remain obscure. Geranylgeranyl pyrophosphate (GGPP), a non-sterol intermediate of the mevalonate pathway, is the substrate for protein geranylgeranylation, protein post-translational modification catalyzed by protein geranylgeranyl transferase I (GGTase I). Pyrin is an innate immune sensor that forms an active inflammasome in response to bacterial toxins. Mutations in MEFV (encoding human PYRIN) cause autoinflammatory Familial Mediterranean Fever (FMF) syndrome. Here, we show that protein geranylgeranylation enables Toll-like receptor (TLR)-induced phosphatidylinositol-3-OH kinase PI(3)K) activation by promoting the interaction between the small GTPase Kras and the PI(3)K catalytic subunit p110δ. Macrophages deficient for GGTase I or p110δ exhibited constitutive interleukin-1β release that was MEFV-dependent, but NLRP3-, AIM2- and NLRC4- inflammasome independent. In the absence of protein geranylgeranylation, compromised PI(3)K activity allows for an unchecked TLR-induced inflammatory responses and constitutive activation of the Pyrin inflammasome. PMID:27270400

  11. Construction of a controllable β-carotene biosynthetic pathway by decentralized assembly strategy in Saccharomyces cerevisiae.

    PubMed

    Xie, Wenping; Liu, Min; Lv, Xiaomei; Lu, Wenqiang; Gu, Jiali; Yu, Hongwei

    2014-01-01

    Saccharomyces cerevisiae is an important platform organism for the synthesis of a great number of natural products. However, the assembly of controllable and genetically stable heterogeneous biosynthetic pathways in S. cerevisiae still remains a significant challenge. Here, we present a strategy for reconstructing controllable multi-gene pathways by employing the GAL regulatory system. A set of marker recyclable integrative plasmids (pMRI) was designed for decentralized assembly of pathways. As proof-of-principle, a controllable β-carotene biosynthesis pathway (∼16 kb) was reconstructed and optimized by repeatedly using GAL10-GAL1 bidirectional promoters with high efficiency (80-100%). By controling the switch time of the pathway, production of 11 mg/g DCW of total carotenoids (72.57 mg/L) and 7.41 mg/g DCW of β-carotene was achieved in shake-flask culture. In addition, the engineered yeast strain exhibited high genetic stability after 20 generations of subculture. The results demonstrated a controllable and genetically stable biosynthetic pathway capable of increasing the yield of target products. Furthermore, the strategy presented in this study could be extended to construct other pathways in S. cerevisisae.

  12. Modular control of multiple pathways using engineered orthogonal T7 polymerases

    PubMed Central

    Temme, Karsten; Hill, Rena; Segall-Shapiro, Thomas H.; Moser, Felix; Voigt, Christopher A.

    2012-01-01

    Synthetic genetic sensors and circuits enable programmable control over the timing and conditions of gene expression. They are being increasingly incorporated into the control of complex, multigene pathways and cellular functions. Here, we propose a design strategy to genetically separate the sensing/circuitry functions from the pathway to be controlled. This separation is achieved by having the output of the circuit drive the expression of a polymerase, which then activates the pathway from polymerase-specific promoters. The sensors, circuits and polymerase are encoded together on a ‘controller’ plasmid. Variants of T7 RNA polymerase that reduce toxicity were constructed and used as scaffolds for the construction of four orthogonal polymerases identified via part mining that bind to unique promoter sequences. This set is highly orthogonal and induces cognate promoters by 8- to 75-fold more than off-target promoters. These orthogonal polymerases enable four independent channels linking the outputs of circuits to the control of different cellular functions. As a demonstration, we constructed a controller plasmid that integrates two inducible systems, implements an AND logic operation and toggles between metabolic pathways that change Escherichia coli green (deoxychromoviridans) and red (lycopene). The advantages of this organization are that (i) the regulation of the pathway can be changed simply by introducing a different controller plasmid, (ii) transcription is orthogonal to host machinery and (iii) the pathway genes are not transcribed in the absence of a controller and are thus more easily carried without invoking evolutionary pressure. PMID:22743271

  13. Carbon Monoxide Induces Cytoprotection in Rat Orthotopic Lung Transplantation via Anti-Inflammatory and Anti-Apoptotic Effects

    PubMed Central

    Song, Ruiping; Kubo, Masatoshi; Morse, Danielle; Zhou, Zhihong; Zhang, Xuchen; Dauber, James H.; Fabisiak, James; Alber, Sean M.; Watkins, Simon C.; Zuckerbraun, Brian S.; Otterbein, Leo E.; Ning, Wen; Oury, Tim D.; Lee, Patty J.; McCurry, Kenneth R.; Choi, Augustine M.K.

    2003-01-01

    Successful lung transplantation has been limited by the high incidence of acute graft rejection. There is mounting evidence that the stress response gene heme oxygenase-1 (HO-1) and/or its catalytic by-product carbon monoxide (CO) confers cytoprotection against tissue and cellular injury. This led us to hypothesize that CO may protect against lung transplant rejection via its anti-inflammatory and antiapoptotic effects. Orthotopic left lung transplantation was performed in Lewis rat recipients from Brown-Norway rat donors. HO-1 mRNA and protein expression were markedly induced in transplanted rat lungs compared to sham-operated control lungs. Transplanted lungs developed severe intraalveolar hemorrhage, marked infiltration of inflammatory cells, and intravascular coagulation. However, in the presence of CO exposure (500 ppm), the gross anatomy and histology of transplanted lungs showed marked preservation. Furthermore, transplanted lungs displayed increased apoptotic cell death compared with the transplanted lungs of CO-exposed recipients, as assessed by TUNEL and caspase-3 immunostaining. CO exposure inhibited the induction of IL-6 mRNA and protein expression in lung and serum, respectively. Gene array analysis revealed that CO also down-regulated other proinflammatory genes, including MIP-1α and MIF, and growth factors such as platelet-derived growth factor, which were up-regulated by transplantation. These data suggest that the anti-inflammatory and antiapoptotic properties of CO confer potent cytoprotection in a rat model of lung transplantation. PMID:12819027

  14. Synthetic chemically modified mrna-based delivery of cytoprotective factor promotes early cardiomyocyte survival post-acute myocardial infarction.

    PubMed

    Huang, Chien-Ling; Leblond, Anne-Laure; Turner, Elizebeth C; Kumar, Arun Hs; Martin, Kenneth; Whelan, Derek; O'Sullivan, Donnchadh M; Caplice, Noel M

    2015-03-02

    To extend the temporal window for cytoprotection in cardiomyocytes undergoing apoptosis after hypoxia and myocardial infarction (MI), a synthetic chemically modified mRNA (modRNA) was used to drive delivery of insulin-like growth factor-1 (IGF1) within the area at risk in an in vivo murine model of MI. Delivery of IGF1 modRNA, with a polyethylenimine-based nanoparticle, augmented secreted and cell-associated IGF1, promoting cardiomyocyte survival and abrogating cell apoptosis under hypoxia-induced apoptosis conditions. Translation of modRNA-IGF1 was sufficient to induce downstream increases in the levels of Akt and Erk phosphorylation. Downregulation of IGF1 specific miRNA-1 and -133 but not miR-145 expression was also confirmed. As a proof of concept, intramyocardial delivery of modRNA-IGF1 but not control modRNA-GFP significantly decreased the level of TUNEL positive cells, augmented Akt phosphorylation, and decreased caspase-9 activity within the infarct border zone 24 h post-MI. These findings demonstrate the potential for an extended cytoprotective effect of transient IGF1 driven by synthetic modRNA delivery.

  15. Applications of genetically-encoded biosensors for the construction and control of biosynthetic pathways.

    PubMed

    Michener, Joshua K; Thodey, Kate; Liang, Joe C; Smolke, Christina D

    2012-05-01

    Cells are filled with biosensors, molecular systems that measure the state of the cell and respond by regulating host processes. In much the same way that an engineer would monitor a chemical reactor, the cell uses these sensors to monitor changing intracellular environments and produce consistent behavior despite the variable environment. While natural systems derive a clear benefit from pathway regulation, past research efforts in engineering cellular metabolism have focused on introducing new pathways and removing existing pathway regulation. Synthetic biology is a rapidly growing field that focuses on the development of new tools that support the design, construction, and optimization of biological systems. Recent advances have been made in the design of genetically-encoded biosensors and the application of this class of molecular tools for optimizing and regulating heterologous pathways. Biosensors to cellular metabolites can be taken directly from natural systems, engineered from natural sensors, or constructed entirely in vitro. When linked to reporters, such as antibiotic resistance markers, these metabolite sensors can be used to report on pathway productivity, allowing high-throughput screening for pathway optimization. Future directions will focus on the application of biosensors to introduce feedback control into metabolic pathways, providing dynamic control strategies to increase the efficient use of cellular resources and pathway reliability.

  16. Aryl hydrocarbon receptor control of a disease tolerance defence pathway.

    PubMed

    Bessede, Alban; Gargaro, Marco; Pallotta, Maria T; Matino, Davide; Servillo, Giuseppe; Brunacci, Cinzia; Bicciato, Silvio; Mazza, Emilia M C; Macchiarulo, Antonio; Vacca, Carmine; Iannitti, Rossana; Tissi, Luciana; Volpi, Claudia; Belladonna, Maria L; Orabona, Ciriana; Bianchi, Roberta; Lanz, Tobias V; Platten, Michael; Della Fazia, Maria A; Piobbico, Danilo; Zelante, Teresa; Funakoshi, Hiroshi; Nakamura, Toshikazu; Gilot, David; Denison, Michael S; Guillemin, Gilles J; DuHadaway, James B; Prendergast, George C; Metz, Richard; Geffard, Michel; Boon, Louis; Pirro, Matteo; Iorio, Alfonso; Veyret, Bernard; Romani, Luigina; Grohmann, Ursula; Fallarino, Francesca; Puccetti, Paolo

    2014-07-10

    Disease tolerance is the ability of the host to reduce the effect of infection on host fitness. Analysis of disease tolerance pathways could provide new approaches for treating infections and other inflammatory diseases. Typically, an initial exposure to bacterial lipopolysaccharide (LPS) induces a state of refractoriness to further LPS challenge (endotoxin tolerance). We found that a first exposure of mice to LPS activated the ligand-operated transcription factor aryl hydrocarbon receptor (AhR) and the hepatic enzyme tryptophan 2,3-dioxygenase, which provided an activating ligand to the former, to downregulate early inflammatory gene expression. However, on LPS rechallenge, AhR engaged in long-term regulation of systemic inflammation only in the presence of indoleamine 2,3-dioxygenase 1 (IDO1). AhR-complex-associated Src kinase activity promoted IDO1 phosphorylation and signalling ability. The resulting endotoxin-tolerant state was found to protect mice against immunopathology in Gram-negative and Gram-positive infections, pointing to a role for AhR in contributing to host fitness.

  17. Cytotoxicity and cytoprotective activity of naphthalenediols in rat cortical neurons.

    PubMed

    Flueraru, Mihaela; So, Remmick; Willmore, William G; Poulter, Michael O; Durst, Tony; Charron, Martin; Wright, James S

    2006-09-01

    Some members of the naphthalenediol family have been shown in previous work on PC-12 cells to act as effective antioxidants while being relatively nontoxic. In the present work, we extend that study to examine the effect of naphthalenediols on rat primary cortical neurons exposed to AAPH (2,2'-azobis (2-amidinopropane) hydrochloride), a source of peroxyl radicals. Compounds tested included the acetylated forms of 1,2-naphthalenediol, that is, 1,2-ND, as well as 1,4-ND, 2,3-ND, 1,8-ND, and the known highly potent antioxidant (-)-epigallocatechin gallate (EGCG). In cytoxicity studies, cells were exposed to the compounds for 24 h, leading to observed toxicity in the order of 1,4-ND > 1,2 ND > 2,3-ND approximately EGCG > 1,8-ND. In cytoprotection studies, the desired compounds were incubated with neurons prior to AAPH exposure, and live cell counts were determined by trypan blue and/or MTT assays. Excellent protection, superior to EGCG, was provided by 2,3-ND and 1,8-ND. Additional studies using glutamate as a stressor showed that 1,8-ND had a significant protective effect at concentrations as low as 500 nM. The results can be understood on the basis of the tendency (or lack thereof) to form the corresponding quinone, which in turn depends on whether or not there is a loss of aromaticity in the ring adjacent to the quinone moiety. Thus, certain members of the family of naphthalenediols are quite cytotoxic, whereas others show promise as neuroprotective antioxidants.

  18. Critical Roles of the Direct GABAergic Pallido-cortical Pathway in Controlling Absence Seizures

    PubMed Central

    Li, Min; Ma, Tao; Wu, Shengdun; Ma, Jingling; Cui, Yan; Xia, Yang; Xu, Peng; Yao, Dezhong

    2015-01-01

    The basal ganglia (BG), serving as an intermediate bridge between the cerebral cortex and thalamus, are believed to play crucial roles in controlling absence seizure activities generated by the pathological corticothalamic system. Inspired by recent experiments, here we systematically investigate the contribution of a novel identified GABAergic pallido-cortical pathway, projecting from the globus pallidus externa (GPe) in the BG to the cerebral cortex, to the control of absence seizures. By computational modelling, we find that both increasing the activation of GPe neurons and enhancing the coupling strength of the inhibitory pallido-cortical pathway can suppress the bilaterally synchronous 2–4 Hz spike and wave discharges (SWDs) during absence seizures. Appropriate tuning of several GPe-related pathways may also trigger the SWD suppression, through modulating the activation level of GPe neurons. Furthermore, we show that the previously discovered bidirectional control of absence seizures due to the competition between other two BG output pathways also exists in our established model. Importantly, such bidirectional control is shaped by the coupling strength of this direct GABAergic pallido-cortical pathway. Our work suggests that the novel identified pallido-cortical pathway has a functional role in controlling absence seizures and the presented results might provide testable hypotheses for future experimental studies. PMID:26496656

  19. [Various mechanisms of cytoprotective effect of omeprazole and low intensity laser radiation on the gastroduodenal mucosa in the treatment of patients with duodenal ulcer].

    PubMed

    Akhmadkhodzhaev, A M

    2002-01-01

    Clinical studies were made in 130 patients with duodenal ulcer in the phase of exacerbation of the disease. There were 98 men and 32 women who ranged from 17 to 50 years old. Results of examination of 7 essentially healthy subjects were regarded as control. The patients were divided into three groups. Group I patients (n = 48) received a conventional therapy; in group II patients, the adopted therapy was supplemented by omeprazol, 20 mg twice daily, group III patients (n = 43) were (in addition to the above therapeutic regimen) exposed to a session of endoscopic low-intensity laser irradiation (LILI) for 5 min (overall 6 to 8 LILI procedures). It has been ascertained that omeprazol exerts a cytoprotective effect on the mucozal barrier of the gastroduodenal zone brought about by increase in the synthesis of glucoproteins in the mucous membrane, improvement of the water-and-elastic properties, and enhancement of resistance of the mucosal barrier to the action of the aggressive factors. Administration of endoscopic LILI treatments in DU patients has also been found out to have a cytoprotective effect but superior to omeprazol. A protective action of LILI is believed to be caused by stimulation of synthesis of the most important components of glycoproteins. A cytoprotective effect of omeprazol and endoscopic LILI is ccompanied by a significant shortening of time for the clinical symptoms to get dispelled, the ulcer cicatrization frequency increased.

  20. Renin secretion and total body sodium: pathways of integrative control.

    PubMed

    Bie, Peter; Damkjaer, Mads

    2010-02-01

    1. Herein, we review mechanisms of sodium balance operating at constant mean arterial blood pressure (MABP); that is, under conditions where MABP does not provide the primary signal to the kidney. 2. Relative constancy of body fluids requires accurate regulation of total body sodium (TBS). Normally, plenty of sodium is ingested and balance is achieved by control of renal excretion driven by multiple central nervous, cardiovascular, endocrine and renal tubular mechanisms. Subtle changes in sodium balance are associated with parallel changes in extracellular volume (due to fast and precise osmoregulation), but not necessarily in MABP. Therefore, signals other than MABP seem to be the primary link between TBS and kidney function. 3. Renal functions involved in sodium homeostasis include: (i) the rate of glomerular filtration (GFR) determined by renal haemodynamics, including tubuloglomerular feedback (TGF); (ii) proximal tubular reabsorption involving glomerulotubular balance (GTB) and neurohumoral control; (iii) macula densa mechanisms influencing TGF and renin secretion; and (iv) distal tubular reabsorption dominated by the renin-angiotensin-aldosterone system (RAAS). 4. The present review focuses on the interactive, homeostatic operation of TBS, MABP, GTB, TGF and the RAAS. Regulation of sodium balance involves neurohumoral control of tubular sodium reabsorption, including proximal reabsorption. Central nervous system-mediated regulation of the latter modulates renin secretion. Homeostatically, the RAAS-TGF interaction seems analogous to a spring-shock absorber set-up: non-adaptive RAAS functions determine the new steady state position, whereas TGF controls the rate of change. Recruitment of renin-secreting cells during sustained stimulation may be essential for chronic adaptation, although details of this afferent arteriolar cell plasticity are unclear at present.

  1. Controlling Inelastic Light Scattering Quantum Pathways in Graphene

    DTIC Science & Technology

    2011-03-31

    dielectric21,22. Figure 1a displays a diagram of a typical device . The carrier concentration in graphene is controlled by the top gate voltage (Vg). The doping...dependence of electrical transport, optical transmis- sion and inelastic light scattering are measured on the same graphene devices . Figure 1b shows...the electrical resistance curve of a graphene device , which has a charge neutral point (CNP) at 1.2V. The resistance decreases from the CNP value on

  2. Midazolam provides cytoprotective effect during corticosterone-induced damages in rat astrocytes by stimulating steroidogenesis.

    PubMed

    Guo, Wen-Zhi; Miao, Yu-Liang; An, Li-Na; Wang, Xiao-Yun; Pan, Ning-Ling; Ma, Ya-Qun; Chen, Hong-Xia; Zhao, Nan; Zhang, Hong; Li, Yun-Feng; Mi, Wei-Dong

    2013-06-28

    Midazolam is a benzodiazepine derivative drug that has powerful anxiolytic, amnestic, hypnotic, and sedative properties. The cytoprotective effect of midazolam on brain astrocytes is poorly understood. This study aimed to investigate the cytoprotective effect of midazolam on astrocytes exposed to corticosterone, a stress-produced glucocorticoid. We found that midazolam stimulated pregnenolone and progesterone secretion in astrocytes in a dose-dependent manner. Midazolam protected astrocytes from corticosterone-induced damages in a dose-dependent manner. In addition, we demonstrated that progesterone reduced corticosterone-induced damages. Finally, we applied trilostane, an inhibitor of 3β-hydroxysteroid dehydrogenase, to inhibit pregnenolone metabolism and found that pretreatment with trilostane significantly inhibited the cytoprotective effect of midazolam on corticosterone-induced cytotoxicity in rat astrocytes in a dose-dependent manner. Taken together, these results demonstrate that midazolam has cytoprotective effect on astrocytes. This is, at least partially, derived from midazolam-induced steroidogenesis including progesterone and downstream products in astrocytes. Our data provide new insights into the cytoprotective effect of midazolam.

  3. Clinical perspectives for the use of melatonin as a chronobiotic and cytoprotective agent.

    PubMed

    Cardinali, Daniel P; Furio, Analía M; Reyes, María P

    2005-12-01

    The circadian time system involves periodic gene expression at the cellular level, synchronized by a hierarchically superior structure located in the hypothalamic suprachiasmatic nuclei. Treatment of circadian rhythm disorders has led to the development of a new type of agent called "chronobiotics," among which melatonin is the prototype. In elderly insomniacs, melatonin treatment decreased sleep latency and increased sleep efficiency, particularly slow-wave sleep. The effect of melatonin on sleep is the consequence of increasing sleep propensity (by augmenting the amplitude of circadian clock oscillation via MT1 receptors) and of synchronizing the circadian clock via MT2 receptors. Daily melatonin production decreases with age and in several pathologies, attaining its lowest values in Alzheimer's disease (AD) patients. About 45% of AD patients have disruptions in their sleep and "sundowning" agitation. Generally, melatonin treatment decreases sundowning in AD patients and reduced variability of sleep onset time. Both open and controlled studies have indicated a significant decrease of cognitive deterioration in AD patients treated with melatonin. The mechanisms accounting for the possible therapeutic effect of melatonin in AD patients may be manifold. On one hand, melatonin treatment promotes slow-wave sleep in the elderly and could be beneficial by augmenting the restorative phases of sleep. On the other hand, melatonin protects neurons against beta-amyloid toxicity. By its combined chronobiotic and cytoprotective properties melatonin provides an innovative neuroprotective strategy to reduce the cost of lifetime treatment of some neuropsychiatric disorders.

  4. Cytoprotective effect of silymarin against diabetes-induced cardiomyocyte apoptosis in diabetic rats.

    PubMed

    Tuorkey, Muobarak J; El-Desouki, Nabila I; Kamel, Rabab A

    2015-01-01

    The beneficial effects of silymarin have been extensively studied in the context of inflammation and cancer treatment, yet much less is known about its therapeutic effect on diabetes. The present study was aimed to investigate the cytoprotective activity of silymarin against diabetes-induced cardiomyocyte apoptosis. Rats were randomly divided into: control group, untreated diabetes group and diabetes group treated with silymarin (120 mg/kg•d) for 10 d. Rats were sacrificed, and the cardiac muscle specimens and blood samples were collected. The immunoreactivity of caspase-3 and Bcl-2 in the cardiomyocytes was measured. Total proteins, glucose, insulin, creatinine, AST, ALT, cholesterol, and triglycerides levels were estimated. Unlike the treated diabetes group, cardiomyocyte apoptosis increased in the untreated rats, as evidenced by enhanced caspase-3 and declined Bcl-2 activities. The levels of glucose, creatinine, AST, ALT, cholesterol, and triglycerides declined in the treated rats. The declined levels of insulin were enhanced again after treatment of diabetic rats with silymarin, reflecting a restoration of the pancreatic β-cells activity. The findings of this study are of great importance, which confirmed for the first time that treatment of diabetic subjects with silymarin may protect cardiomyocytes against apoptosis and promote survival-restoration of the pancreatic β-cells. Copyright © 2015 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  5. Synthetic Growth Hormone-Releasing Peptides (GHRPs): A Historical Appraisal of the Evidences Supporting Their Cytoprotective Effects

    PubMed Central

    Berlanga-Acosta, Jorge; Abreu-Cruz, Angel; Barco Herrera, Diana García-del; Mendoza-Marí, Yssel; Rodríguez-Ulloa, Arielis; García-Ojalvo, Ariana; Falcón-Cama, Viviana; Hernández-Bernal, Francisco; Beichen, Qu; Guillén-Nieto, Gerardo

    2017-01-01

    Background: Growth hormone-releasing peptides (GHRPs) constitute a group of small synthetic peptides that stimulate the growth hormone secretion and the downstream axis activity. Mounting evidences since the early 1980s delineated unexpected pharmacological cardioprotective and cytoprotective properties for the GHRPs. However, despite intense basic pharmacological research, alternatives to prevent cell and tissue demise before lethal insults have remained as an empty niche in the clinical armamentarium. Here, we have rigorously reviewed the investigational development of GHRPs and their clinical niching perspectives. Methodology: PubMed/MEDLINE databases, including original research and review articles, were explored. The search design was date escalated from 1980 and included articles in English only. Results and Conclusions: GHRPs bind to two different receptors (GHS-R1a and CD36), which redundantly or independently exert relevant biological effects. GHRPs’ binding to CD36 activates prosurvival pathways such as PI-3K/AKT1, thus reducing cellular death. Furthermore, GHRPs decrease reactive oxygen species (ROS) spillover, enhance the antioxidant defenses, and reduce inflammation. These cytoprotective abilities have been revealed in cardiac, neuronal, gastrointestinal, and hepatic cells, representing a comprehensive spectrum of protection of parenchymal organs. Antifibrotic effects have been attributed to some of the GHRPs by counteracting fibrogenic cytokines. In addition, GHRP family members have shown a potent myotropic effect by promoting anabolia and inhibiting catabolia. Finally, GHRPs exhibit a broad safety profile in preclinical and clinical settings. Despite these fragmented lines incite to envision multiple pharmacological uses for GHRPs, especially as a myocardial reperfusion damage-attenuating candidate, this family of “drugable” peptides awaits for a definitive clinical niche. PMID:28469491

  6. Palmitoylation at Cys595 is essential for PECAM-1 localisation into membrane microdomains and for efficient PECAM-1-mediated cytoprotection.

    PubMed

    Sardjono, Caroline T; Harbour, Stacey N; Yip, Jana C; Paddock, Cathy; Tridandapani, Susheela; Newman, Peter J; Jackson, Denise E

    2006-12-01

    The Ig-ITIM superfamily member, PECAM-1 acts as a negative regulator of ITAM-signalling pathways in platelets involving GPVI/FcR gamma chain and Fc?RIIa. This negative feedback loop involves regulation of collagen and GPVI-dependent aggregation events, platelet-thrombus-growth on immobilised collagen under flow and Fc?RIIa-mediated platelet responses. In this study, we show that PECAM-1 is selectively palmitoylated involving a thioester linkage with an unpaired cysteine residue at amino acid position 595 in its cytoplasmic domain. As palmitoylation is known to target proteins to membrane microdomains, we investigated the microdomain localisation for PECAM-1 in platelets and nucleated cells. In unstimulated platelets, approximately 20% of PECAM-1 is localised to Triton-insoluble microdomain fractions and it does not increase with platelet activation by collagen, collagen-related peptide, thrombin- or human-aggregated IgG. PECAM-1 is in close physical proximity with GPVI in platelet microdomains. Removal of platelet cytoskeleton prior to sucrose-density-gradient separation showed that PECAM-1 was associated with both the Triton-soluble and membrane skeleton in microdomain-associated fractions. Disruption of microdomains by membrane-cholesterol depletion resulted in loss of PECAM-1 localisation to membrane microdomains. Mutational analysis of juxtamembrane cysteine residue to alanine (C595A) of human PECAM-1 resulted in loss of palmitoylation and a sixfold decrease in association with membrane microdomains. Functionally, the palmitoylated cysteine 595 residue is required, in part, for efficient PECAM-1-mediated cytoprotection. These results show that cysteine 595 is required for constitutive association of PECAM-1 with membrane microdomains and PECAM-1-mediated cytoprotection, where it may act as a crucial regulator of signaling and apoptosis events.

  7. Functional anatomy of neural pathways contributing to the control of song production in birds.

    PubMed

    Wild, J M

    1997-10-01

    In birds, as in humans, vocal control involves the intricate coordination of three major groups of muscles, namely, those of the vocal organ, the respiratory apparatus, and the vocal tract, including the jaw and tongue. The neural pathways involved in the control of each of these groups of muscles are described for songbirds and compared with those in non-oscine birds and mammals. The pathway in songbirds that controls the syrinx, the bird's vocal organ, originates in the telencephalon and projects via the occipito-mesencephalic tract directly upon vocal motoneurons in the medulla. Activity in this pathway configures the syrinx into phonatory positions for the production of species typical vocalizations. Another component of this pathway mediates control of respiration during vocalization, since it projects upon both expiratory and inspiratory groups of premotor neurons in the ventrolateral medulla, as well as upon several other nuclei en route. This pathway appears to be primarily involved with the control of the temporal pattern of song, but is also importantly involved in the control of vocal intensity, mediated via air sac pressure. There are extensive interconnections between the vocal and respiratory pathways, especially at brainstem levels, and it may be these that ensure the necessary temporal coordination of syringeal and respiratory activity. The pathway mediating control of the jaw appears to be different from those mediating control of the syrinx and respiratory muscles. It originates in a different part of the telencephalon and projects upon premotor neurons in the medulla that, on preliminary analysis, appear to be separate from those projecting upon the syringeal motor nucleus. The separateness of this pathway may reflect the imperfect correlation of jaw movements with the dynamic and acoustic features of song. The brainstem pathways mediating control of vocalization and respiration in songbirds have distinct similarities to those in non-oscine birds

  8. [Controls of the plant endomembrane-secretory pathway]. Final report

    SciTech Connect

    Not Available

    1991-12-31

    These studies are focused on elucidating the molecular structure of plant cell membranes with special reference to cell surface glycoproteins. The studies reported herein include use of monoclonal antibodies to characterize cell surface epitopes, construction of cDNA libraries of cell surface proteins, isolation of plant cell mutants by flow cytometry, detection of beta-glucouronidase marker enzyme systems in plants, expression go VSVG (the major envelope glycoprotein of Vesicular Stomatis Virus) in plant cells, and control of gene expression of cell membrane glycoproteins.(DT)

  9. (Controls of the plant endomembrane-secretory pathway)

    SciTech Connect

    Not Available

    1991-01-01

    These studies are focused on elucidating the molecular structure of plant cell membranes with special reference to cell surface glycoproteins. The studies reported herein include use of monoclonal antibodies to characterize cell surface epitopes, construction of cDNA libraries of cell surface proteins, isolation of plant cell mutants by flow cytometry, detection of beta-glucouronidase marker enzyme systems in plants, expression go VSVG (the major envelope glycoprotein of Vesicular Stomatis Virus) in plant cells, and control of gene expression of cell membrane glycoproteins.(DT)

  10. Control of basal ganglia output by direct and indirect pathway projection neurons.

    PubMed

    Freeze, Benjamin S; Kravitz, Alexxai V; Hammack, Nora; Berke, Joshua D; Kreitzer, Anatol C

    2013-11-20

    The direct and indirect efferent pathways from striatum ultimately reconverge to influence basal ganglia output nuclei, which in turn regulate behavior via thalamocortical and brainstem motor circuits. However, the distinct contributions of these two efferent pathways in shaping basal ganglia output are not well understood. We investigated these processes using selective optogenetic control of the direct and indirect pathways, in combination with single-unit recording in the basal ganglia output nucleus substantia nigra pars reticulata (SNr) in mice. Optogenetic activation of striatal direct and indirect pathway projection neurons produced diverse cellular responses in SNr neurons, with stimulation of each pathway eliciting both excitations and inhibitions. Despite this response heterogeneity, the effectiveness of direct pathway stimulation in producing movement initiation correlated selectively with the subpopulation of inhibited SNr neurons. In contrast, effective indirect pathway-mediated motor suppression was most strongly influenced by excited SNr neurons. Our results support the theory that key basal ganglia output neurons serve as an inhibitory gate over motor output that can be opened or closed by striatal direct and indirect pathways, respectively.

  11. Control of Basal Ganglia Output by Direct and Indirect Pathway Projection Neurons

    PubMed Central

    Freeze, Benjamin S.; Kravitz, Alexxai V.; Hammack, Nora; Berke, Joshua D.

    2013-01-01

    The direct and indirect efferent pathways from striatum ultimately reconverge to influence basal ganglia output nuclei, which in turn regulate behavior via thalamocortical and brainstem motor circuits. However, the distinct contributions of these two efferent pathways in shaping basal ganglia output are not well understood. We investigated these processes using selective optogenetic control of the direct and indirect pathways, in combination with single-unit recording in the basal ganglia output nucleus substantia nigra pars reticulata (SNr) in mice. Optogenetic activation of striatal direct and indirect pathway projection neurons produced diverse cellular responses in SNr neurons, with stimulation of each pathway eliciting both excitations and inhibitions. Despite this response heterogeneity, the effectiveness of direct pathway stimulation in producing movement initiation correlated selectively with the subpopulation of inhibited SNr neurons. In contrast, effective indirect pathway-mediated motor suppression was most strongly influenced by excited SNr neurons. Our results support the theory that key basal ganglia output neurons serve as an inhibitory gate over motor output that can be opened or closed by striatal direct and indirect pathways, respectively. PMID:24259575

  12. Deprivation of asparagine triggers cytoprotective autophagy in laryngeal squamous cell carcinoma.

    PubMed

    Ji, Yunxiang; Li, Li; Tao, Qilei; Zhang, Xuyao; Luan, Jingyun; Zhao, Shuwei; Liu, Huanhai; Ju, Dianwen

    2017-03-28

    Laryngeal squamous cell carcinoma (LSCC), one of the most common malignancies in the head and neck, has poor prognosis and high mortality. The need of novel and effective treatment for LSCC is urgent. Asparaginase, an enzyme-depriving asparagine, has been employed for the treatment of various cancers. In this study, we reported for the first time that asparaginase could induce remarkable cytotoxicity and caspase-dependent apoptosis in human LSCC Tu212 and Tu686 cells. Meanwhile, autophagy was triggered by asparaginase in LSCC cells, which was confirmed by accumulation of autophagosomes and the conversion of light chain 3-I (LC3-I) to LC3-II. Importantly, inhibition of autophagy by chloroquine (CQ) significantly enhanced asparaginase-induced cytotoxicity, indicating that autophagy has a cytoprotective role in asparaginase-treated LSCC cells. Meanwhile, we found that mitochondrial-originated reactive oxygen species (ROS) participated in asparaginase-induced autophagy and cytotoxicity. N-acetyl-L-cysteine (NAC), a common antioxidant, was employed to scavenge ROS, and our results demonstrated that NAC could significantly block asparaginase-induced autophagy and attenuate asparaginase-induced cytotoxicity, indicating that intracellular ROS played a crucial role in asparagine deprivation therapy. Furthermore, western blot analysis showed that asparaginase-induced autophagy was mediated by inactivation of Akt/mTOR and activation of the Erk signaling pathway in Tu212 and Tu686 cells. Therefore, these results indicated the protective role of autophagy in asparaginase-treated LSCC cells and provided a new attractive therapeutic strategy for LSCC by asparaginase alone or in combination with autophagic inhibitors.

  13. Influenza A virus targets a cGAS-independent STING pathway that controls enveloped RNA viruses.

    PubMed

    Holm, Christian K; Rahbek, Stine H; Gad, Hans Henrik; Bak, Rasmus O; Jakobsen, Martin R; Jiang, Zhaozaho; Hansen, Anne Louise; Jensen, Simon K; Sun, Chenglong; Thomsen, Martin K; Laustsen, Anders; Nielsen, Camilla G; Severinsen, Kasper; Xiong, Yingluo; Burdette, Dara L; Hornung, Veit; Lebbink, Robert Jan; Duch, Mogens; Fitzgerald, Katherine A; Bahrami, Shervin; Mikkelsen, Jakob Giehm; Hartmann, Rune; Paludan, Søren R

    2016-02-19

    Stimulator of interferon genes (STING) is known be involved in control of DNA viruses but has an unexplored role in control of RNA viruses. During infection with DNA viruses STING is activated downstream of cGAMP synthase (cGAS) to induce type I interferon. Here we identify a STING-dependent, cGAS-independent pathway important for full interferon production and antiviral control of enveloped RNA viruses, including influenza A virus (IAV). Further, IAV interacts with STING through its conserved hemagglutinin fusion peptide (FP). Interestingly, FP antagonizes interferon production induced by membrane fusion or IAV but not by cGAMP or DNA. Similar to the enveloped RNA viruses, membrane fusion stimulates interferon production in a STING-dependent but cGAS-independent manner. Abolishment of this pathway led to reduced interferon production and impaired control of enveloped RNA viruses. Thus, enveloped RNA viruses stimulate a cGAS-independent STING pathway, which is targeted by IAV.

  14. Influenza A virus targets a cGAS-independent STING pathway that controls enveloped RNA viruses

    PubMed Central

    Holm, Christian K.; Rahbek, Stine H.; Gad, Hans Henrik; Bak, Rasmus O.; Jakobsen, Martin R.; Jiang, Zhaozaho; Hansen, Anne Louise; Jensen, Simon K.; Sun, Chenglong; Thomsen, Martin K.; Laustsen, Anders; Nielsen, Camilla G.; Severinsen, Kasper; Xiong, Yingluo; Burdette, Dara L.; Hornung, Veit; Lebbink, Robert Jan; Duch, Mogens; Fitzgerald, Katherine A.; Bahrami, Shervin; Mikkelsen, Jakob Giehm; Hartmann, Rune; Paludan, Søren R.

    2016-01-01

    Stimulator of interferon genes (STING) is known be involved in control of DNA viruses but has an unexplored role in control of RNA viruses. During infection with DNA viruses STING is activated downstream of cGAMP synthase (cGAS) to induce type I interferon. Here we identify a STING-dependent, cGAS-independent pathway important for full interferon production and antiviral control of enveloped RNA viruses, including influenza A virus (IAV). Further, IAV interacts with STING through its conserved hemagglutinin fusion peptide (FP). Interestingly, FP antagonizes interferon production induced by membrane fusion or IAV but not by cGAMP or DNA. Similar to the enveloped RNA viruses, membrane fusion stimulates interferon production in a STING-dependent but cGAS-independent manner. Abolishment of this pathway led to reduced interferon production and impaired control of enveloped RNA viruses. Thus, enveloped RNA viruses stimulate a cGAS-independent STING pathway, which is targeted by IAV. PMID:26893169

  15. A closed-loop control scheme for steering steady states of glycolysis and glycogenolysis pathway.

    PubMed

    Panja, Surajit; Patra, Sourav; Mukherjee, Anirban; Basu, Madhumita; Sengupta, Sanghamitra; Dutta, Pranab K

    2013-01-01

    Biochemical networks normally operate in the neighborhood of one of its multiple steady states. It may reach from one steady state to other within a finite time span. In this paper, a closed-loop control scheme is proposed to steer states of the glycolysis and glycogenolysis (GG) pathway from one of its steady states to other. The GG pathway is modeled in the synergism and saturation system formalism, known as S-system. This S-system model is linearized into the controllable Brunovsky canonical form using a feedback linearization technique. For closed-loop control, the linear-quadratic regulator (LQR) and the linear-quadratic gaussian (LQG) regulator are invoked to design a controller for tracking prespecified steady states. In the feedback linearization technique, a global diffeomorphism function is proposed that facilitates in achieving the regulation requirement. The robustness of the regulated GG pathway is studied considering input perturbation and with measurement noise.

  16. Structure and Assembly Pathway of the Ribosome Quality Control Complex

    PubMed Central

    Shao, Sichen; Brown, Alan; Santhanam, Balaji; Hegde, Ramanujan S.

    2015-01-01

    Summary During ribosome-associated quality control, stalled ribosomes are split into subunits and the 60S-housed nascent polypeptides are poly-ubiquitinated by Listerin. How this low-abundance ubiquitin ligase targets rare stall-generated 60S among numerous empty 60S is unknown. Here, we show that Listerin specificity for nascent chain-60S complexes depends on nuclear export mediator factor (NEMF). The 3.6 Å cryo-EM structure of a nascent chain-containing 60S-Listerin-NEMF complex revealed that NEMF makes multiple simultaneous contacts with 60S and peptidyl-tRNA to sense nascent chain occupancy. Structural and mutational analyses showed that ribosome-bound NEMF recruits and stabilizes Listerin’s N-terminal domain, while Listerin’s C-terminal RWD domain directly contacts the ribosome to position the adjacent ligase domain near the nascent polypeptide exit tunnel. Thus, highly specific nascent chain targeting by Listerin is imparted by the avidity gained from a multivalent network of context-specific individually weak interactions, highlighting a new principle of client recognition during protein quality control. PMID:25578875

  17. Soluble factors from Lactobacillus GG activate MAPKs and induce cytoprotective heat shock proteins in intestinal epithelial cells.

    PubMed

    Tao, Yun; Drabik, Kenneth A; Waypa, Tonya S; Musch, Mark W; Alverdy, John C; Schneewind, Olaf; Chang, Eugene B; Petrof, Elaine O

    2006-04-01

    Conditioned media from the probiotic Lactobacillus GG (LGG-CM) induce heat shock protein (Hsp) expression in intestinal epithelial cells. LGG-CM induces both Hsp25 and Hsp72 in a time- and concentration-dependent manner. These effects are mediated by a low-molecular-weight peptide that is acid and heat stable. DNA microarray experiments demonstrate that Hsp72 is one of the most highly upregulated genes in response to LGG-CM treatment. Real-time PCR and electrophoretic mobility shift assay confirm that regulation of Hsp induction is at least in part transcriptional in nature, involving heat shock factor-1. Although Hsps are not induced for hours after exposure, transient exposure to LGG-CM is sufficient to initiate the signal for Hsp induction, suggesting that signal transduction pathways may be involved. Experiments confirm that LGG-CM modulates the activity of certain signaling pathways in intestinal epithelial cells by activating MAP kinases. Inhibitors of p38 and JNK block the expression of Hsp72 normally induced by LGG-CM. Functional studies indicate that LGG-CM treatment of gut epithelial cells protects them from oxidant stress, perhaps by preserving cytoskeletal integrity. By inducing the expression of cytoprotective Hsps in gut epithelial cells, and by activating signal transduction pathways, the peptide product(s) secreted by LGG may contribute to the beneficial clinical effects attributed to this probiotic.

  18. Cytoprotective mechanisms of DJ-1 against oxidative stress through modulating ERK1/2 and ASK1 signal transduction.

    PubMed

    Oh, Stephanie E; Mouradian, M Maral

    2017-09-18

    DJ-1 is a highly conserved multifunctional protein linked to both neurodegeneration and neoplasia. Among its various activities is an antioxidant property leading to cytoprotection under oxidative stress conditions. This is associated with the ability to modulate signal transduction events that determine how the cell regulates normal processes such as growth, senescence, apoptosis, and autophagy in order to adapt to environmental stimuli and stresses. Alterations in DJ-1 expression or function can disrupt homeostatic signaling networks and initiate cascades that play a role in the pathogenesis of conditions such as Parkinson's disease and cancer. DJ-1 plays a major role in various signaling pathways. Related to its anti-oxidant properties, it mediates cell survival and proliferation by activating the extracellular signal-regulated kinase (ERK1/2) pathway and attenuates cell death signaling by inhibiting apoptosis signal-regulating kinase 1 (ASK1) activation. Here, we review the ways through which DJ-1 regulates these pathways, focusing on how its regulation of signal transduction contributes to cellular homeostasis and the pathologic states that result from their dysregulation. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  19. Upstream Pathways Controlling Mitochondrial Function in Major Psychosis

    PubMed Central

    Machado, Alencar Kolinski; Pan, Alexander Yongshuai; da Silva, Tatiane Morgana; Duong, Angela

    2016-01-01

    Mitochondrial dysfunction is commonly observed in bipolar disorder (BD) and schizophrenia (SCZ) and may be a central feature of psychosis. These illnesses are complex and heterogeneous, which is reflected by the complexity of the processes regulating mitochondrial function. Mitochondria are typically associated with energy production; however, dysfunction of mitochondria affects not only energy production but also vital cellular processes, including the formation of reactive oxygen species, cell cycle and survival, intracellular Ca2+ homeostasis, and neurotransmission. In this review, we characterize the upstream components controlling mitochondrial function, including 1) mutations in nuclear and mitochondrial DNA, 2) mitochondrial dynamics, and 3) intracellular Ca2+ homeostasis. Characterizing and understanding the upstream factors that regulate mitochondrial function is essential to understand progression of these illnesses and develop biomarkers and therapeutics. PMID:27310240

  20. Global regulatory pathways and cross-talk control pseudomonas aeruginosa environmental lifestyle and virulence phenotype.

    PubMed

    Coggan, Kimberly A; Wolfgang, Matthew C

    2012-01-01

    Pseudomonas aeruginosa is a metabolically versatile environmental bacterium and an opportunistic human pathogen that relies on numerous signaling pathways to sense, respond, and adapt to fluctuating environmental cues. Although the environmental signals sensed by these pathways are poorly understood, they are largely responsible for determining whether P. aeruginosa adopts a planktonic or sessile lifestyle. These environmental lifestyle extremes parallel the acute and chronic infection phenotypes observed in human disease. In this review, we focus on four major pathways (cAMP/Vfr and c-di-GMP signaling, quorum sensing, and the Gac/Rsm pathway) responsible for sensing and integrating external stimuli into coherent regulatory control at the transcriptional, translational, and post-translational level. A common theme among these pathways is the inverse control of factors involved in promoting motility and acute infection and those associated with biofilm formation and chronic infection. In many instances these regulatory pathways influence one another, forming a complex network allowing P. aeruginosa to assimilate numerous external signals into an integrated regulatory circuit that controls a lifestyle continuum.

  1. Control of metabolic flux through the quinate pathway in Aspergillus nidulans.

    PubMed Central

    Wheeler, K A; Lamb, H K; Hawkins, A R

    1996-01-01

    The quinic acid ulitization (qut) pathway in Aspergillus nidulans is a dispensable carbon utilization pathway that catabolizes quinate to protocatechuate via dehydroquinate and dehydroshikimate(DHS). At the usual in vitro growth pH of 6.5, quinate enters the mycelium by means of a specific permease and is converted into PCA by the sequential action of the enzymes quinate dehydrogenase, 3-dehydroquinase and DHS dehydratase. The extent of control on metabolic flux exerted by the permease and the three pathway enzymes was investigated by applying the techniques of Metabolic Control Analysis. The flux control coefficients for each of the three quinate pathway enzymes were determined empirically, and the flux control coefficient of the quinate permease was inferred by use of the summation theorem. There measurements implied that, under the standard growth conditions used, the values for the flux control coefficients of the components of the quinate pathway were: quinate permease, 0.43; quinate dehydrogenase, 0.36; dehydroquinase, 0.18; DHS dehydratase, <0,03. Attempts to partially decouple quinate permease from the control over flux by measuring flux at pH 3.5 (when a significant percentage of the soluble quinate is protonated and able to enter the mycelium without the aid of a permease) led to an increase of approx. 50% in the flux control coefficient for dehydroquinase. Taken together with the fact that A. nidulans has a very efficient pH homeostasis mechanism, these experiments are consistent with the view that quinate permease exerts a high degree of control over pathway flux under the standard laboratory growth conditions at pH 6.5. The enzymes quinate dehydrogenase and 3-dehydroquinase have previously been overproduced in Escherichia coli, and protocols for their purification published. The remaining qut pathway enzyme DHS dehydratase was overproduced in E. coli and a purification protocol established. The purified DHS dehydratase was shown to have a K(m) of 530

  2. Synthesis, antioxidant and cytoprotective evaluation of potential antiatherogenic phenolic hydrazones. A structure-activity relationship insight.

    PubMed

    Vanucci-Bacqué, Corinne; Carayon, Chantal; Bernis, Corinne; Camare, Caroline; Nègre-Salvayre, Anne; Bedos-Belval, Florence; Baltas, Michel

    2014-08-01

    A novel series of hydrazones derived from substituted benzaldehydes have been synthesized as potential antiatherogenic agents. Several methods were used for exploring their antioxidant and cytoprotective properties, such as their scavenging effect on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, the inhibition of superoxide anion (O₂(·-)) generation and the measurement of cell-induced low-density lipoprotein oxidation (monitored by the formation of TBARS). The cytoprotective efficacy was also evaluated by measuring the cell viability (monitored by the MTT assay) in the presence of cytotoxic oxidized LDL. In this report, we discuss the relationship between the chemical structure of phenolic hydrazones and their antioxidant and cytoprotective activities, for subsequent application as antiatherogenic agents. This SAR study confirms that the phenolic frame is not the only prerequisite for antioxidant activity and N-methylbenzothiazole hydrazone moiety magnifies the dual required properties in two most interesting derivatives.

  3. Cytoprotective effect of seaweeds with high antioxidant activity from the Peniche coast (Portugal).

    PubMed

    Pinteus, Susete; Silva, Joana; Alves, Celso; Horta, André; Fino, Nádia; Rodrigues, Ana Inês; Mendes, Susana; Pedrosa, Rui

    2017-03-01

    Screening of antioxidant potential of dichloromethane and methanolic extracts of twenty-seven seaweeds from the Peniche coast was performed by: total phenolic contents (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and oxygen radical absorbance capacity (ORAC). Seaweeds revealing the highest antioxidant activity were screened for cytoprotective potential in MCF-7 cells, including the mitochondrial membrane potential analysis and the caspase-9 activity. High correlation was found between TPC of seaweed extracts and their scavenging capacity on DPPH and peroxyl radicals. The highest antioxidant activity was displayed by the methanolic fraction of brown seaweeds belonging to Fucales, however Ulva compressa presented the highest cytoprotective effect by blunting the apoptosis process. These results suggest that high antioxidant activity may not be directly related with high cytoprotective potential. Thus, seaweeds reveal to be a promising source of compounds with potential against oxidative stress.

  4. Cellular Metabolomics Revealed the Cytoprotection of Amentoflavone, a Natural Compound, in Lipopolysaccharide-Induced Injury of Human Umbilical Vein Endothelial Cells

    PubMed Central

    Yao, Weifeng; Li, Hui; Liu, Qinan; Gao, Ye; Dai, Jin; Bao, Beihua; Zhang, Li; Ding, Anwei

    2016-01-01

    Amentoflavone is one of the important bioactive flavonoids in the ethylacetate extract of “Cebaiye”, which is a blood cooling and hematostatic herb in traditional Chinese medicine. The previous work in our group has demonstrated that the ethylacetate extract of Cebaiye has a notable antagonistic effect on the injury induced by lipopolysaccharide (LPS) to human umbilical vein endothelial cells (HUVECs). The present investigation was designed to assess the effects and possible mechanism of cytoprotection of amentoflavone via metabolomics. Ultra-performance liquid chromatography/quadrupole time of flight-mass spectrometry (UPLC/QTOF-MS) coupled with multivariate data analysis was used to characterize the variations in the metabolites of HUVECs in response to exposure to LPS and amentoflavone treatment. Seven putative metabolites (glycine, argininosuccinic acid, putrescine, ornithine, spermidine, 5-oxoproline and dihydrouracil) were discovered in cells incubated with LPS and/or amentoflavone. Functional pathway analysis uncovered that the changes of these metabolites related to various significant metabolic pathways (glutathione metabolism, arginine and proline metabolism, β-alanine metabolism and glycine, serine and threonine metabolism), which may explain the potential cytoprotection function of amentoflavone. These findings also demonstrate that cellular metabolomics through UPLC/QTOF-MS is a powerful tool for detecting variations in a range of intracellular compounds upon toxin and/or drug exposure. PMID:27618027

  5. Cellular Metabolomics Revealed the Cytoprotection of Amentoflavone, a Natural Compound, in Lipopolysaccharide-Induced Injury of Human Umbilical Vein Endothelial Cells.

    PubMed

    Yao, Weifeng; Li, Hui; Liu, Qinan; Gao, Ye; Dai, Jin; Bao, Beihua; Zhang, Li; Ding, Anwei

    2016-09-09

    Amentoflavone is one of the important bioactive flavonoids in the ethylacetate extract of "Cebaiye", which is a blood cooling and hematostatic herb in traditional Chinese medicine. The previous work in our group has demonstrated that the ethylacetate extract of Cebaiye has a notable antagonistic effect on the injury induced by lipopolysaccharide (LPS) to human umbilical vein endothelial cells (HUVECs). The present investigation was designed to assess the effects and possible mechanism of cytoprotection of amentoflavone via metabolomics. Ultra-performance liquid chromatography/quadrupole time of flight-mass spectrometry (UPLC/QTOF-MS) coupled with multivariate data analysis was used to characterize the variations in the metabolites of HUVECs in response to exposure to LPS and amentoflavone treatment. Seven putative metabolites (glycine, argininosuccinic acid, putrescine, ornithine, spermidine, 5-oxoproline and dihydrouracil) were discovered in cells incubated with LPS and/or amentoflavone. Functional pathway analysis uncovered that the changes of these metabolites related to various significant metabolic pathways (glutathione metabolism, arginine and proline metabolism, β-alanine metabolism and glycine, serine and threonine metabolism), which may explain the potential cytoprotection function of amentoflavone. These findings also demonstrate that cellular metabolomics through UPLC/QTOF-MS is a powerful tool for detecting variations in a range of intracellular compounds upon toxin and/or drug exposure.

  6. Dysferlin mediates the cytoprotective effects of TRAF2 following myocardial ischemia reperfusion injury.

    PubMed

    Tzeng, Huei-Ping; Evans, Sarah; Gao, Feng; Chambers, Kari; Topkara, Veli K; Sivasubramanian, Natarajan; Barger, Philip M; Mann, Douglas L

    2014-02-26

    We have demonstrated that tumor necrosis factor (TNF) receptor-associated factor 2 (TRAF2), a scaffolding protein common to TNF receptors 1 and 2, confers cytoprotection in the heart. However, the mechanisms for the cytoprotective effects of TRAF2 are not known. Mice with cardiac-restricted overexpression of low levels of TRAF2 (MHC-TRAF2LC) and a dominant negative TRAF2 (MHC-TRAF2DN) were subjected to ischemia (30-minute) reperfusion (60-minute) injury (I/R), using a Langendorff apparatus. MHC-TRAF2LC mice were protected against I/R injury as shown by a significant ≈27% greater left ventricular (LV) developed pressure after I/R, whereas mice with impaired TRAF2 signaling had a significantly ≈38% lower LV developed pressure, a ≈41% greater creatine kinase (CK) release, and ≈52% greater Evans blue dye uptake after I/R, compared to LM. Transcriptional profiling of MHC-TRAF2LC and MHC-TRAF2DN mice identified a calcium-triggered exocytotic membrane repair protein, dysferlin, as a potential cytoprotective gene responsible for the cytoprotective effects of TRAF2. Mice lacking dysferlin had a significant ≈39% lower LV developed pressure, a ≈20% greater CK release, and ≈29% greater Evans blue dye uptake after I/R, compared to wild-type mice, thus phenocopying the response to tissue injury in the MHC-TRAF2DN mice. Moreover, breeding MHC-TRAF2LC onto a dysferlin-null background significantly attenuated the cytoprotective effects of TRAF2 after I/R injury. The study shows that dysferlin, a calcium-triggered exocytotic membrane repair protein, is required for the cytoprotective effects of TRAF2-mediated signaling after I/R injury.

  7. Dysferlin Mediates the Cytoprotective Effects of TRAF2 Following Myocardial Ischemia Reperfusion Injury

    PubMed Central

    Tzeng, Huei‐Ping; Evans, Sarah; Gao, Feng; Chambers, Kari; Topkara, Veli K.; Sivasubramanian, Natarajan; Barger, Philip M.; Mann, Douglas L.

    2014-01-01

    Background We have demonstrated that tumor necrosis factor (TNF) receptor‐associated factor 2 (TRAF2), a scaffolding protein common to TNF receptors 1 and 2, confers cytoprotection in the heart. However, the mechanisms for the cytoprotective effects of TRAF2 are not known. Methods/Results Mice with cardiac‐restricted overexpression of low levels of TRAF2 (MHC‐TRAF2LC) and a dominant negative TRAF2 (MHC‐TRAF2DN) were subjected to ischemia (30‐minute) reperfusion (60‐minute) injury (I/R), using a Langendorff apparatus. MHC‐TRAF2LC mice were protected against I/R injury as shown by a significant ≈27% greater left ventricular (LV) developed pressure after I/R, whereas mice with impaired TRAF2 signaling had a significantly ≈38% lower LV developed pressure, a ≈41% greater creatine kinase (CK) release, and ≈52% greater Evans blue dye uptake after I/R, compared to LM. Transcriptional profiling of MHC‐TRAF2LC and MHC‐TRAF2DN mice identified a calcium‐triggered exocytotic membrane repair protein, dysferlin, as a potential cytoprotective gene responsible for the cytoprotective effects of TRAF2. Mice lacking dysferlin had a significant ≈39% lower LV developed pressure, a ≈20% greater CK release, and ≈29% greater Evans blue dye uptake after I/R, compared to wild‐type mice, thus phenocopying the response to tissue injury in the MHC‐TRAF2DN mice. Moreover, breeding MHC‐TRAF2LC onto a dysferlin‐null background significantly attenuated the cytoprotective effects of TRAF2 after I/R injury. Conclusion The study shows that dysferlin, a calcium‐triggered exocytotic membrane repair protein, is required for the cytoprotective effects of TRAF2‐mediated signaling after I/R injury. PMID:24572254

  8. The microRNA pathway controls germ cell proliferation and differentiation in C. elegans

    PubMed Central

    Bukhari, Syed Irfan Ahmad; Vasquez-Rifo, Alejandro; Gagné, Dominic; Paquet, Eric R; Zetka, Monique; Robert, Claude; Masson, Jean-Yves; Simard, Martin J

    2012-01-01

    The discovery of the miRNA pathway revealed a new layer of molecular control of biological processes. To uncover new functions of this gene regulatory pathway, we undertook the characterization of the two miRNA-specific Argonaute proteins in Caenorhabditis elegans, ALG-1 and ALG-2. We first observed that the loss-of-function of alg-1 and alg-2 genes resulted in reduced progeny number. An extensive analysis of the germline of these mutants revealed a reduced mitotic region, indicating fewer proliferating germ cells. We also observed an early entry into meiosis in alg-1 and alg-2 mutant animals. We detected ALG-1 and ALG-2 protein expressions in the distal tip cell (DTC), a specialized cell located at the tip of both C. elegans gonadal arms that regulates mitosis-meiosis transition. Re-establishing the expression of alg-1 specifically in the DTC of mutant animals partially rescued the observed germline defects. Further analyses also support the implication of the miRNA pathway in gametogenesis. Interestingly, we observed that disruption of five miRNAs expressed in the DTC led to similar phenotypes. Finally, gene expression analysis of alg-1 mutant gonads suggests that the miRNA pathway is involved in the regulation of different pathways important for germline proliferation and differentiation. Collectively, our data indicate that the miRNA pathway plays a crucial role in the control of germ cell biogenesis in C. elegans. PMID:22370633

  9. The microRNA pathway controls germ cell proliferation and differentiation in C. elegans.

    PubMed

    Bukhari, Syed Irfan Ahmad; Vasquez-Rifo, Alejandro; Gagné, Dominic; Paquet, Eric R; Zetka, Monique; Robert, Claude; Masson, Jean-Yves; Simard, Martin J

    2012-06-01

    The discovery of the miRNA pathway revealed a new layer of molecular control of biological processes. To uncover new functions of this gene regulatory pathway, we undertook the characterization of the two miRNA-specific Argonaute proteins in Caenorhabditis elegans, ALG-1 and ALG-2. We first observed that the loss-of-function of alg-1 and alg-2 genes resulted in reduced progeny number. An extensive analysis of the germline of these mutants revealed a reduced mitotic region, indicating fewer proliferating germ cells. We also observed an early entry into meiosis in alg-1 and alg-2 mutant animals. We detected ALG-1 and ALG-2 protein expressions in the distal tip cell (DTC), a specialized cell located at the tip of both C. elegans gonadal arms that regulates mitosis-meiosis transition. Re-establishing the expression of alg-1 specifically in the DTC of mutant animals partially rescued the observed germline defects. Further analyses also support the implication of the miRNA pathway in gametogenesis. Interestingly, we observed that disruption of five miRNAs expressed in the DTC led to similar phenotypes. Finally, gene expression analysis of alg-1 mutant gonads suggests that the miRNA pathway is involved in the regulation of different pathways important for germline proliferation and differentiation. Collectively, our data indicate that the miRNA pathway plays a crucial role in the control of germ cell biogenesis in C. elegans.

  10. [From endoplasmic reticulum to Golgi apparatus: a secretory pathway controlled by signal molecules].

    PubMed

    Wang, Jiasheng; Luo, Jianhong; Zhang, Xiaomin

    2013-07-01

    Protein transport from endoplasmic reticulum (ER) to Golgi apparatus has long been known to be a central process for protein quality control and sorting. Recent studies have revealed that a large number of signal molecules are involved in regulation of membrane trafficking through ER, ER-Golgi intermediate compartment and Golgi apparatus. These molecules can significantly change the transport rate of proteins by regulating vesicle budding and fusion. Protein transport from ER to Golgi apparatus is not only controlled by signal pathways triggered from outside the cell, it is also regulated by feedback signals from the transport pathway.

  11. Endoplasmic Reticulum Stress-Induced Autophagy Provides Cytoprotection from Chemical Hypoxia and Oxidant Injury and Ameliorates Renal Ischemia-Reperfusion Injury

    PubMed Central

    Chandrika, Bhavya B.; Yang, Cheng; Ou, Yang; Feng, Xiaoke; Muhoza, Djamali; Holmes, Alexandrea F.; Theus, Sue; Deshmukh, Sarika; Haun, Randy S.; Kaushal, Gur P.

    2015-01-01

    We examined whether endoplasmic reticulum (ER) stress-induced autophagy provides cytoprotection from renal tubular epithelial cell injury due to oxidants and chemical hypoxia in vitro, as well as from ischemia-reperfusion (IR) injury in vivo. We demonstrate that the ER stress inducer tunicamycin triggers an unfolded protein response, upregulates ER chaperone Grp78, and activates the autophagy pathway in renal tubular epithelial cells in culture. Inhibition of ER stress-induced autophagy accelerated caspase–3 activation and cell death suggesting a pro-survival role of ER stress-induced autophagy. Compared to wild-type cells, autophagy-deficient MEFs subjected to ER stress had enhanced caspase–3 activation and cell death, a finding that further supports the cytoprotective role of ER stress-induced autophagy. Induction of autophagy by ER stress markedly afforded cytoprotection from oxidants H2O2 and tert-Butyl hydroperoxide and from chemical hypoxia induced by antimycin A. In contrast, inhibition of ER stress-induced autophagy or autophagy-deficient cells markedly enhanced cell death in response to oxidant injury and chemical hypoxia. In mouse kidney, similarly to renal epithelial cells in culture, tunicamycin triggered ER stress, markedly upregulated Grp78, and activated autophagy without impairing the autophagic flux. In addition, ER stress-induced autophagy markedly ameliorated renal IR injury as evident from significant improvement in renal function and histology. Inhibition of autophagy by chloroquine markedly increased renal IR injury. These studies highlight beneficial impact of ER stress-induced autophagy in renal ischemia-reperfusion injury both in vitro and in vivo. PMID:26444017

  12. Endoplasmic Reticulum Stress-Induced Autophagy Provides Cytoprotection from Chemical Hypoxia and Oxidant Injury and Ameliorates Renal Ischemia-Reperfusion Injury.

    PubMed

    Chandrika, Bhavya B; Yang, Cheng; Ou, Yang; Feng, Xiaoke; Muhoza, Djamali; Holmes, Alexandrea F; Theus, Sue; Deshmukh, Sarika; Haun, Randy S; Kaushal, Gur P

    2015-01-01

    We examined whether endoplasmic reticulum (ER) stress-induced autophagy provides cytoprotection from renal tubular epithelial cell injury due to oxidants and chemical hypoxia in vitro, as well as from ischemia-reperfusion (IR) injury in vivo. We demonstrate that the ER stress inducer tunicamycin triggers an unfolded protein response, upregulates ER chaperone Grp78, and activates the autophagy pathway in renal tubular epithelial cells in culture. Inhibition of ER stress-induced autophagy accelerated caspase-3 activation and cell death suggesting a pro-survival role of ER stress-induced autophagy. Compared to wild-type cells, autophagy-deficient MEFs subjected to ER stress had enhanced caspase-3 activation and cell death, a finding that further supports the cytoprotective role of ER stress-induced autophagy. Induction of autophagy by ER stress markedly afforded cytoprotection from oxidants H2O2 and tert-Butyl hydroperoxide and from chemical hypoxia induced by antimycin A. In contrast, inhibition of ER stress-induced autophagy or autophagy-deficient cells markedly enhanced cell death in response to oxidant injury and chemical hypoxia. In mouse kidney, similarly to renal epithelial cells in culture, tunicamycin triggered ER stress, markedly upregulated Grp78, and activated autophagy without impairing the autophagic flux. In addition, ER stress-induced autophagy markedly ameliorated renal IR injury as evident from significant improvement in renal function and histology. Inhibition of autophagy by chloroquine markedly increased renal IR injury. These studies highlight beneficial impact of ER stress-induced autophagy in renal ischemia-reperfusion injury both in vitro and in vivo.

  13. The Hippo pathway is controlled by Angiotensin II signaling and its reactivation induces apoptosis in podocytes

    PubMed Central

    Wennmann, D O; Vollenbröker, B; Eckart, A K; Bonse, J; Erdmann, F; Wolters, D A; Schenk, L K; Schulze, U; Kremerskothen, J; Weide, T; Pavenstädt, H

    2014-01-01

    The Hippo pathway fulfills a crucial function in controlling the balance between proliferation, differentiation and apoptosis in cells. Recent studies showed that G protein-coupled receptors (GPCRs) serve as upstream regulators of Hippo signaling, that either activate or inactivate the Hippo pathway via the large tumor suppressor kinase (LATS) and its substrate, the co-transcription factor Yes-associated protein (YAP). In this study, we focused on the Angiotensin II type 1 receptor (AT1R), which belongs to the GPCR family and has an essential role in the control of blood pressure and water homeostasis. We found that Angiotensin II (Ang II) inactivates the pathway by decreasing the activity of LATS kinase; therefore, leading to an enhanced nuclear shuttling of unphosphorylated YAP in HEK293T cells. This shuttling of YAP is actin-dependent as disruption of the actin cytoskeleton inhibited dephosphorylation of LATS and YAP. Interestingly, in contrast to HEK293T cells, podocytes, which are a crucial component of the glomerular filtration barrier, display a predominant nuclear YAP localization in vivo and in vitro. Moreover, stimulation with Ang II did not alter Hippo pathway activity in podocytes, which show a deactivated pathway. Reactivation of the LATS kinase activity in podocytes resulted in an increased cytoplasmic YAP localization accompanied by a strong induction of apoptosis. Thus, our work indicates that the control of LATS activation and subsequent YAP localization is important for podocyte homeostasis and survival. PMID:25393475

  14. The molecular choreography of protein synthesis: translational control, regulation, and pathways.

    PubMed

    Chen, Jin; Choi, Junhong; O'Leary, Seán E; Prabhakar, Arjun; Petrov, Alexey; Grosely, Rosslyn; Puglisi, Elisabetta Viani; Puglisi, Joseph D

    2016-01-01

    Translation of proteins by the ribosome regulates gene expression, with recent results underscoring the importance of translational control. Misregulation of translation underlies many diseases, including cancer and many genetic diseases. Decades of biochemical and structural studies have delineated many of the mechanistic details in prokaryotic translation, and sketched the outlines of eukaryotic translation. However, translation may not proceed linearly through a single mechanistic pathway, but likely involves multiple pathways and branchpoints. The stochastic nature of biological processes would allow different pathways to occur during translation that are biased by the interaction of the ribosome with other translation factors, with many of the steps kinetically controlled. These multiple pathways and branchpoints are potential regulatory nexus, allowing gene expression to be tuned at the translational level. As research focus shifts toward eukaryotic translation, certain themes will be echoed from studies on prokaryotic translation. This review provides a general overview of the dynamic data related to prokaryotic and eukaryotic translation, in particular recent findings with single-molecule methods, complemented by biochemical, kinetic, and structural findings. We will underscore the importance of viewing the process through the viewpoints of regulation, translational control, and heterogeneous pathways.

  15. Structure-Activity Relationships in the Cytoprotective Effect of Caffeic Acid Phenethyl Ester (CAPE) and Fluorinated Derivatives: Effects on Heme Oxygenase-1 Induction and Antioxidant Activities

    DTIC Science & Technology

    2010-03-09

    fluorinated derivatives: Effects on heme oxygenase-1 induction and antioxidant activities Xinyu Wang a,b, Salomon Stavchansky a, Sean M. Kerwin c, Phillip D...February 2010 Available online 9 March 2010 Keywords: Caffeic acid phenethyl ester Fluorinated derivative Cytoprotection Oxidative stress Human...acid phenethyl ester (CAPE) as a cytoprotective agent, six catechol ring fluorinated CAPE derivatives were evaluated for their cytoprotective

  16. Role of mitochondria in paricalcitol-mediated cytoprotection during obstructive nephropathy

    PubMed Central

    García, Isabel Mercedes; Altamirano, Liliana; Mazzei, Luciana; Fornés, Miguel; Molina, Marisa Nile; Ferder, León

    2012-01-01

    Vitamin D slows the progression of chronic kidney disease. Furthermore, activators of vitamin D receptors (VDR) have suppressant effects on the renin-angiotensin system, as well as anti-inflammatory and antifibrotic actions. This study aimed to evaluate the cytoprotective effects of paricalcitol, a VDR activator, at the mitochondrial level using an obstructive nephropathy model [unilateral ureteral obstruction (UUO)]. Rats subjected to UUO and controls were treated daily with vehicle or paricalcitol. The control group underwent a sham surgery. The treatment was done for 15 days (30 ng/kg). The following were determined: biochemical parameters; fibrosis; apoptosis; mitochondrial morphology; VDR, AT1 receptor, and NADPH oxidase 4 expression; and NADPH oxidase activity (in total and in mitochondrial fractions from the renal cortex). VDR activation prevented fibrosis (20 ± 5 vs. 60 ± 10%) and the number of TUNEL-positive apoptotic cells (10 ± 3 vs. 25 ± 4) in UUO. Biochemical, histological, and molecular studies suggest mitochondrial injury. Electron microscopy revealed in UUO electronically luminous material in the nucleus. Some mitochondria were increased in size and contained dilated crests and larger than normal spaces in their interiors. These changes were not present with paricalcitol treatment. Additionally, high AT1-receptor mRNA and NADPH activity was reverted in mitochondrial fractions from obstructed paricalcitol-treated animals (0.58 ± 0.06 vs. 0.95 ± 0.05 relative densitometry units and 9,000 ± 800 vs. 15,000 ± 1,000 relative fluorescence units·μg protein−1·min−1, respectively). These changes were consistent with an improvement in VDR expression (0.75 ± 0.05 vs. 0.35 ± 0.04 relative densitometry units). These results suggest that paricalcitol confers a protective effect and reveal, as well, a possible AT1 receptor-dependent protective effect that occurs at the mitochondrial level. PMID:22492946

  17. Adaptive Control Model Reveals Systematic Feedback and Key Molecules in Metabolic Pathway Regulation

    PubMed Central

    Moffitt, Richard A.; Merrill, Alfred H.; Wang, May D.

    2011-01-01

    Abstract Robust behavior in metabolic pathways resembles stabilized performance in systems under autonomous control. This suggests we can apply control theory to study existing regulation in these cellular networks. Here, we use model-reference adaptive control (MRAC) to investigate the dynamics of de novo sphingolipid synthesis regulation in a combined theoretical and experimental case study. The effects of serine palmitoyltransferase over-expression on this pathway are studied in vitro using human embryonic kidney cells. We report two key results from comparing numerical simulations with observed data. First, MRAC simulations of pathway dynamics are comparable to simulations from a standard model using mass action kinetics. The root-sum-square (RSS) between data and simulations in both cases differ by less than 5%. Second, MRAC simulations suggest systematic pathway regulation in terms of adaptive feedback from individual molecules. In response to increased metabolite levels available for de novo sphingolipid synthesis, feedback from molecules along the main artery of the pathway is regulated more frequently and with greater amplitude than from other molecules along the branches. These biological insights are consistent with current knowledge while being new that they may guide future research in sphingolipid biology. In summary, we report a novel approach to study regulation in cellular networks by applying control theory in the context of robust metabolic pathways. We do this to uncover potential insight into the dynamics of regulation and the reverse engineering of cellular networks for systems biology. This new modeling approach and the implementation routines designed for this case study may be extended to other systems. Supplementary Material is available at www.liebertonline.com/cmb. PMID:21314456

  18. Endoplasmic reticulum stress pathway required for immune homeostasis is neurally controlled by arrestin-1.

    PubMed

    Singh, Varsha; Aballay, Alejandro

    2012-09-28

    In response to pathogen infection, the host innate immune system activates microbial killing pathways and cellular stress pathways that need to be balanced because insufficient or excessive immune responses have deleterious consequences. Recent studies demonstrate that two G protein-coupled receptors (GPCRs) in the nervous system of Caenorhabditis elegans control immune homeostasis. To investigate further how GPCR signaling controls immune homeostasis at the organismal level, we studied arrestin-1 (ARR-1), which is the only GPCR adaptor protein in C. elegans. The results indicate that ARR-1 is required for GPCR signaling in ASH, ASI, AQR, PQR, and URX neurons, which control the unfolded protein response and a p38 mitogen-activated protein kinase signaling pathway required for innate immunity. ARR-1 activity also controlled immunity through ADF chemosensory and AFD thermosensory neurons that regulate longevity. Furthermore, we found that although ARR-1 played a key role in the control of immunity by AFD thermosensory neurons, it did not control longevity through these cells. However, ARR-1 partially controlled longevity through ADF neurons.

  19. Major Autonomic Neuroregulatory Pathways Underlying Short- and Long-Term Control of Cardiovascular Function.

    PubMed

    Salman, Ibrahim M

    2016-03-01

    Short-term and long-term blood pressure (BP) regulation and its maintenance at levels adequate to perfuse tissue organs involve an integrated action of multiple neural, cardiovascular, renal, endocrine and local tissue control systems. In the recent year, there has been a growing interest in the understanding of neural pathways key to BP control. For instance, through major advances in studies using both anesthetized and conscious animals, our knowledge of the essential neural mechanisms that subserve the baroreceptor, cardiopulmonary and chemoreceptor reflexes, and those evoked by the activation of stress pathways has dramatically increased. While the importance of these neural pathways in the maintenance of cardiovascular homeostasis is well established, the recognition of the central processing nuclei that integrate various afferent inputs to produce synchronous adjustments of autonomic outflows is still progressively expanding. Based on the literature provided thus far, the present review provides an overview in relation to the important neural determinants of BP control and later offers a concise description of major neuronal pathways that control autonomic outflows to the cardiovascular system in the short and long term.

  20. Salivary Cytoprotective Proteins in Inflammation and Resolution during Experimental Gingivitis--A Pilot Study.

    PubMed

    Aboodi, Guy M; Sima, Corneliu; Moffa, Eduardo B; Crosara, Karla T B; Xiao, Yizhi; Siqueira, Walter L; Glogauer, Michael

    2015-01-01

    The protective mechanisms that maintain periodontal homeostasis in gingivitis and prevent periodontal tissue destruction are poorly understood. The aim of this study was to identify changes in the salivary proteome during experimental gingivitis. We used oral neutrophil quantification and whole saliva (WS) proteomics to assess changes that occur in the inflammatory and resolution phases of gingivitis in healthy individuals. Oral neutrophils and WS samples were collected and clinical parameters measured on days 0, 7, 14, 21, 28, and 35. Increased oral neutrophil recruitment and salivary cytoprotective proteins increased progressively during inflammation and decreased in resolution. Oral neutrophil numbers in gingival inflammation and resolution correlated moderately with salivary β-globin, thioredoxin, and albumin and strongly with collagen alpha-1 and G-protein coupled receptor 98. Our results indicate that changes in salivary cytoprotective proteins in gingivitis are associated with a similar trend in oral neutrophil recruitment and clinical parameters. We found moderate to strong correlations between oral neutrophil numbers and levels of several salivary cytoprotective proteins both in the development of the inflammation and in the resolution of gingivitis. Our proteomics approach identified and relatively quantified specific cytoprotective proteins in this pilot study of experimental gingivitis; however, future and more comprehensive studies are needed to clearly identify and validate those protein biomarkers when gingivitis is active.

  1. Salivary Cytoprotective Proteins in Inflammation and Resolution during Experimental Gingivitis—A Pilot Study

    PubMed Central

    Aboodi, Guy M.; Sima, Corneliu; Moffa, Eduardo B.; Crosara, Karla T. B.; Xiao, Yizhi; Siqueira, Walter L.; Glogauer, Michael

    2016-01-01

    Objective: The protective mechanisms that maintain periodontal homeostasis in gingivitis and prevent periodontal tissue destruction are poorly understood. The aim of this study was to identify changes in the salivary proteome during experimental gingivitis. Study design: We used oral neutrophil quantification and whole saliva (WS) proteomics to assess changes that occur in the inflammatory and resolution phases of gingivitis in healthy individuals. Oral neutrophils and WS samples were collected and clinical parameters measured on days 0, 7, 14, 21, 28, and 35. Results: Increased oral neutrophil recruitment and salivary cytoprotective proteins increased progressively during inflammation and decreased in resolution. Oral neutrophil numbers in gingival inflammation and resolution correlated moderately with salivary β-globin, thioredoxin, and albumin and strongly with collagen alpha-1 and G-protein coupled receptor 98. Conclusions: Our results indicate that changes in salivary cytoprotective proteins in gingivitis are associated with a similar trend in oral neutrophil recruitment and clinical parameters. Clinical relevance: We found moderate to strong correlations between oral neutrophil numbers and levels of several salivary cytoprotective proteins both in the development of the inflammation and in the resolution of gingivitis. Our proteomics approach identified and relatively quantified specific cytoprotective proteins in this pilot study of experimental gingivitis; however, future and more comprehensive studies are needed to clearly identify and validate those protein biomarkers when gingivitis is active. PMID:26779447

  2. A GO-Se nanocomposite as an antioxidant nanozyme for cytoprotection.

    PubMed

    Huang, Yanyan; Liu, Chaoqun; Pu, Fang; Liu, Zhen; Ren, Jinsong; Qu, Xiaogang

    2017-03-09

    GO-Se nanocomposites are fabricated with excellent glutathione peroxidase (GPx)-like properties to protect cells against oxidative stress. Compared with SeNPs, the GO-Se nanozymes exhibit higher GPx-mimic catalytic efficiency. Cell experiments further confirm their excellent cytoprotection capacity.

  3. Antioxidant and cytoprotective properties of infusions from leaves and inflorescences of Achillea collina Becker ex Rchb.

    PubMed

    Giorgi, Annamaria; Bombelli, Raffaella; Luini, Alessandra; Speranza, Giovanna; Cosentino, Marco; Lecchini, Sergio; Cocucci, Maurizio

    2009-04-01

    Plants are the main source of molecules with antioxidant and radical scavenging properties that aid the natural defence systems of cells and may be involved in the preservation of human health, particularly preventing all the physiopathological conditions where oxidative damage is a hallmark. Achillea collina Becker ex Rchb. is a medicinal plant of the Achillea millefolium aggregate (yarrow) traditionally used, particularly in mountain areas, as an infusion or alcohol extract for its digestive, antiinflammatory, analgesic, antipyretic and wound healing properties. The aim of this study was to investigate the antioxidant capacity and cytoprotective activity against oxidative stress of infusions obtained from the leaves and inflorescences of Achillea collina Becker ex Rchb., assessed by chemical (free radical scavenging activity by DPPH and Folin Ciocalteu assay) and biological assays (in vitro model of cytotoxicity and lipid peroxidation in PC12 cells line). Infusions of leaves had the highest antioxidant properties and cytoprotective activity. The antioxidant capacity was significantly correlated with the total phenolic content but not with the cytoprotective profile. Achillea collina Becker ex Rchb. has good antioxidant and cytoprotective properties, suggesting further investigations on its chemical composition and potential health value, particularly for traditionally prepared infusions of leaves. (c) 2008 John Wiley & Sons, Ltd.

  4. Advanced Sensors and Controls for Building Applications: Market Assessment and Potential R&D Pathways

    SciTech Connect

    Brambley, Michael R.; Haves, Philip; McDonald, Sean C.; Torcellini, Paul; Hansen, David G.; Holmberg, David; Roth, Kurt

    2005-04-13

    Significant energy savings can be achieved in commercial building operation, along with increased comfort and control for occupants, through the implementation of advanced technologies. This document provides a market assessment of existing building sensors and controls and presents a range of technology pathways (R&D options) for pursuing advanced sensors and building control strategies. This paper is actually a synthesis of five other white papers: the first describes the market assessment including estimates of market potential and energy savings for sensors and control strategies currently on the market as well as a discussion of market barriers to these technologies. The other four cover technology pathways: (1) current applications and strategies for new applications, (2) sensors and controls, (3) networking, security, and protocols and standards, and (4) automated diagnostics, performance monitoring, commissioning, optimal control and tools. Each technology pathway chapter gives an overview of the technology or application. This is followed by a discussion of needs and the current status of the technology. Finally, a series of research topics is proposed.

  5. Induced peroxidase and cytoprotective enzyme expressions support adaptation of HUVECs to sustain subsequent H2O2 exposure.

    PubMed

    Patel, Hemang; Chen, Juan; Kavdia, Mahendra

    2016-01-01

    H2O2 mediates autocrine and paracrine signaling in the vasculature and can propagate endothelial dysfunction. However, it is not clear how endothelial cells withstand H2O2 exposure and promote H2O2-induced vascular remodeling. To understand the innate ability of endothelial cells for sustaining excess H2O2 exposure, we investigated the genotypic and functional regulation of redox systems in primary HUVECs following an H2O2 treatment. Primary HUVECs were exposed to transient H2O2 exposure and consistent H2O2 exposure. Following H2O2 treatments for 24, 48 and 72 h, we measured O2(-) production, mitochondrial membrane polarization (MMP), and gene expressions of pro-oxidative enzymes, peroxidase enzymes, and cytoprotective intermediates. Our results showed that the 24 h H2O2 exposure significantly increased O2(-) levels, hyperpolarized MMP, and downregulated CAT, GPX1, TXNRD1, NFE2L2, ASK1, and ATF2 gene expression in HUVECs. At 72 h, HUVECs in both treatment conditions were shown to adapt to reduce O2(-) levels and normalize MMP. An upregulation of GPX1, TXNRD1, and HMOX1 gene expression and a recovery of NFE2L2 and PRDX1 gene expression to control levels were observed in both consistent and transient treatments at 48 and 72 h. The response of endothelial cells to excess levels of H2O2 involves a complex interaction amongst O2(-) levels, mitochondrial membrane polarization and anti- and pro-oxidant gene regulation. As a part of this response, HUVECs induce cytoprotective mechanisms including the expression of peroxidase and antioxidant enzymes along with the downregulation of pro-apoptotic genes. This adaptation assists HUVECs to withstand subsequent exposures to H2O2. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Hypofractionated and accelerated radiotherapy with subcutaneous amifostine cytoprotection as short adjuvant regimen after breast-conserving surgery: interim report.

    PubMed

    Koukourakis, Michael I; Tsoutsou, Pelagia G; Abatzoglou, Ioannis M; Sismanidou, Kyriaki; Giatromanolaki, Alexandra; Sivridis, Efthimios

    2009-07-15

    Short radiotherapy schedules might be more convenient for patients and overloaded radiotherapy departments, provided late toxicity is not increased. We evaluated the efficacy and toxicity of a hypofractionated and highly accelerated radiotherapy regimen supported with cytoprotection provided by amifostine in breast cancer patients treated with breast-conserving surgery. A total of 92 patients received 12 consecutive fractions of radiotherapy (3.5 Gy/fraction for 10 fractions) to the breast and/or axillary/supraclavicular area and 4 Gy/fraction for 2 fractions to the tumor bed). Amifostine at a dose of 1,000 mg/d was administered subcutaneously. The follow-up of patients was 30-60 months (median, 39). Using a dose individualization algorithm, 77.1% of patients received 1,000 mg and 16.3% received 750 mg of amifostine daily. Of the 92 patients, 13% interrupted amifostine because of fever/rash symptoms. Acute Grade 2 breast toxicity developed in 6.5% of patients receiving 1,000 mg of amifostine compared with 46.6% of the rest of the patients (p < .0001). The incidence of Grade 2 late sequelae was less frequent in the high amifostine dose group (3.2% vs. 6.6%; p = NS). Grade 1 lung fibrosis was infrequent (3.3%). The in-field relapse rate was 3.3%, and an additional 2.2% of patients developed a relapse in the nonirradiated supraclavicular area. c-erbB-2 overexpression was linked to local control failure (p = .01). Distant metastasis appeared in 13% of patients, and this was marginally related to more advanced T/N stage (p = .06). Within a minimal follow-up of 2.5 years after therapy, hypofractionated and accelerated radiotherapy with subcutaneous amifostine cytoprotection has proved a well-tolerated and effective regimen. Longer follow-up is required to assess the long-term late sequelae.

  7. Characterizing the cytoprotective activity of Sarracenia purpurea L., a medicinal plant that inhibits glucotoxicity in PC12 cells.

    PubMed

    Harris, Cory S; Asim, Muhammad; Saleem, Ammar; Haddad, Pierre S; Arnason, John T; Bennett, Steffany A L

    2012-12-05

    The purple pitcher plant, Sarracenia purpurea L., is a widely distributed species in North America with a history of use as both a marketed pain therapy and a traditional medicine in many aboriginal communities. Among the Cree of Eeyou Istchee in northern Québec, the plant is employed to treat symptoms of diabetes and the leaf extract demonstrates multiple anti-diabetic activities including cytoprotection in an in vitro model of diabetic neuropathy. The current study aimed to further investigate this activity by identifying the plant parts and secondary metabolites that contribute to these cytoprotective effects. Ethanolic extracts of S. purpurea leaves and roots were separately administered to PC12 cells exposed to glucose toxicity with subsequent assessment by two cell viability assays. Assay-guided fractionation of the active extract and fractions was then conducted to identify active principles. Using high pressure liquid chromatography together with mass spectrometry, the presence of identified actives in both leaf and root extracts were determined. The leaf extract, but not that of the root, prevented glucose-mediated cell loss in a concentration-dependent manner. Several fractions elicited protective effects, indicative of multiple active metabolites, and, following subfractionation of the polar fraction, hyperoside (quercetin-3-O-galactoside) and morroniside were isolated as active constituents. Phytochemical analysis confirmed the presence of hyperoside in the leaf but not root extract and, although morroniside was detected in both organs, its concentration was seven times higher in the leaf. Our results not only support further study into the therapeutic potential and safety of S. purpurea as an alternative and complementary treatment for diabetic complications associated with glucose toxicity but also identify active principles that can be used for purposes of standardization and quality control.

  8. Hypofractionated and Accelerated Radiotherapy With Subcutaneous Amifostine Cytoprotection as Short Adjuvant Regimen After Breast-Conserving Surgery: Interim Report

    SciTech Connect

    Koukourakis, Michael I.

    2009-07-15

    Purpose: Short radiotherapy schedules might be more convenient for patients and overloaded radiotherapy departments, provided late toxicity is not increased. We evaluated the efficacy and toxicity of a hypofractionated and highly accelerated radiotherapy regimen supported with cytoprotection provided by amifostine in breast cancer patients treated with breast-conserving surgery. Methods and Materials: A total of 92 patients received 12 consecutive fractions of radiotherapy (3.5 Gy/fraction for 10 fractions) to the breast and/or axillary/supraclavicular area and 4 Gy/fraction for 2 fractions to the tumor bed). Amifostine at a dose of 1,000 mg/d was administered subcutaneously. The follow-up of patients was 30-60 months (median, 39). Results: Using a dose individualization algorithm, 77.1% of patients received 1,000 mg and 16.3% received 750 mg of amifostine daily. Of the 92 patients, 13% interrupted amifostine because of fever/rash symptoms. Acute Grade 2 breast toxicity developed in 6.5% of patients receiving 1,000 mg of amifostine compared with 46.6% of the rest of the patients (p < .0001). The incidence of Grade 2 late sequelae was less frequent in the high amifostine dose group (3.2% vs. 6.6%; p = NS). Grade 1 lung fibrosis was infrequent (3.3%). The in-field relapse rate was 3.3%, and an additional 2.2% of patients developed a relapse in the nonirradiated supraclavicular area. c-erbB-2 overexpression was linked to local control failure (p = .01). Distant metastasis appeared in 13% of patients, and this was marginally related to more advanced T/N stage (p = .06). Conclusion: Within a minimal follow-up of 2.5 years after therapy, hypofractionated and accelerated radiotherapy with subcutaneous amifostine cytoprotection has proved a well-tolerated and effective regimen. Longer follow-up is required to assess the long-term late sequelae.

  9. Chemical Characterization and Cytoprotective Effect of the Hydroethanol Extract from Annona coriacea Mart. (Araticum)

    PubMed Central

    Júnior, José G. A. S.; Coutinho, Henrique D. M.; Boris, Ticiana C. C.; Cristo, Janyketchuly S.; Pereira, Nara L. F.; Figueiredo, Fernando G.; Cunha, Francisco A. B.; Aquino, Pedro E. A.; Nascimento, Polyana A. C.; Mesquita, Francisco J. C.; Moreira, Paulo H. F.; Coutinho, Sáskia T. B.; Souza, Ivon T.; Teixeira, Gabriela C.; Ferreira, Najla M. N.; Farina, Eleonora O.; Torres, Cícero M. G.; Holanda, Vanderlan N.; Pereira, Vandbergue S.; Guedes, Maria I. F.

    2016-01-01

    Introduction: Annona coriacea Mart. (araticum) is a widely distributed tree in the cerrado. Its value is attributed principally to the consumption of its fruit which possesses a large nutritive potential. The objective was to identify the chemical profile and evaluate the antimicrobial and cytoprotective activity of the hydroethanol extract of A. coriacea Mart. (HEAC) leaves against the toxicity of mercury chloride. Materials and Methods: The characterization of components was carried out using high-performance liquid chromatography (HPLC). The minimum inhibitory concentration (MIC) was determined by microdilution method in broth with strains of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. For evaluation of the modulatory and cytoprotective activity of aminoglycoside antibiotics (gentamicin and amikacin) and mercury chloride (HgCl2), the substances were associated with the HEAC at subinhibitory concentrations (MIC/8). Results and Discussion: The HPLC analysis revealed the presence of flavonoids such as Luteolin (1.84%) and Quercetin (1.19%) in elevated concentrations. The HEAC presented an MIC ≥512 μg/mL and significant antagonistic action in aminoglycosides modulation, and it also showed cytoprotective activity to S. aureus (significance P < 0.0001) and E. coli (significance P < 0.05) bacteria against the mercury chloride heavy metal with significance, this action being attributed to the chelating properties of the flavonoids found in the chemical identification. Conclusions: The results acquired in this study show that the HEAC presents cytoprotective activity over the tested strains in vitro and can also present antagonistic effect when associated with aminoglycosides, reinforcing the necessity of taking caution when combining natural and pharmaceutical products. SUMMARY The hydroalcoholic extract of A. coriacea Mart. presents in vitro cytoprotective activity against the toxic effect of Hg. Abbreviations Used: HPLC-DAD: High

  10. The LKB1-AMPK pathway: metabolism and growth control in tumor suppression

    PubMed Central

    Shackelford, David B.; Shaw, Reuben J.

    2009-01-01

    In the past decade, studies of the human tumor suppressor LKB1 have uncovered a novel signaling pathway that links cell metabolism to growth control and cell polarity. LKB1 encodes a serine/threonine kinase that directly phosphorylates and activates AMPK, a central metabolic sensor. AMPK regulates lipid, cholesterol and glucose metabolism in specialized metabolic tissues such as liver, muscle, and adipose, a function that has made it a key therapeutic target in patients with diabetes. The connection of AMPK with several tumor suppressors suggests that therapeutic manipulation of this pathway with established diabetes drugs warrants further investigation in patients with cancer. PMID:19629071

  11. The LKB1-AMPK pathway: metabolism and growth control in tumour suppression.

    PubMed

    Shackelford, David B; Shaw, Reuben J

    2009-08-01

    In the past decade, studies of the human tumour suppressor LKB1 have uncovered a novel signalling pathway that links cell metabolism to growth control and cell polarity. LKB1 encodes a serine-threonine kinase that directly phosphorylates and activates AMPK, a central metabolic sensor. AMPK regulates lipid, cholesterol and glucose metabolism in specialized metabolic tissues, such as liver, muscle and adipose tissue. This function has made AMPK a key therapeutic target in patients with diabetes. The connection of AMPK with several tumour suppressors suggests that therapeutic manipulation of this pathway using established diabetes drugs warrants further investigation in patients with cancer.

  12. Suicide by people in a community justice pathway: population-based nested case–control study

    PubMed Central

    King, Carlene; Senior, Jane; Webb, Roger T.; Millar, Tim; Piper, Mary; Pearsall, Alison; Humber, Naomi; Appleby, Louis; Shaw, Jenny

    2015-01-01

    The elevated risk of suicide in prison and after release is a well-recognised and serious problem. Despite this, evidence concerning community-based offenders' suicide risk is sparse. We conducted a population-based nested case–control study of all people in a community justice pathway in England and Wales. Our data show 13% of general population suicides were in community justice pathways before death. Suicide risks were highest among individuals receiving police cautions, and those having recent, or impending prosecution for sexual offences. Findings have implications for the training and practice of clinicians identifying and assessing suicidality, and offering support to those at elevated risk. PMID:26159602

  13. Cytoprotective effect of lacritin on human corneal epithelial cells exposed to benzalkonium chloride in vitro

    PubMed Central

    Feng, Mary M.; Baryla, Julia; Liu, Hong; Laurie, Gordon W.; McKown, Robert L.; Ashki, Negin; Bhayana, Dinesh

    2015-01-01

    Purpose Benzalkonium chloride (BAK) is the most commonly found preservative in eye drops, and has been shown to cause ocular surface inflammation and toxicity. Lacritin is a human tear glycoprotein secreted from the lacrimal glands that has been found to be cytoprotective. This study was designed to determine if the presence of lacritin confers protection to a cultured human corneal epithelial (HCE) cell line, CRL-11515, and primary HCE cells after exposure to the ocular preservative agent BAK. Materials and Methods Recombinant human lacritin was cloned into intein fusion vectors, expressed in E. coli, and purified on chitin beads and DEAE Sepharose. Metabolic curves were established using the MTT assay after exposure of subconfluent CRL-11515 cells to BAK or lacritin. Western blot analysis of lipidated LC3 (LC3-II) provided a measure of autophagy in CRL-11515 cells exposed to lacritin and/or BAK. Results BAK reduced CRL-11515 cellular metabolic activity in a time and dose dependent manner. BAK-induced cellular stress was evident by elevated autophagy that increased with rising concentrations of BAK compared to control (P < 0.05). Lacritin increased HCE cell proliferation at an optimal dose of 1 nM. Preconditioning HCE cells with 1 nM lacritin for 24 hours prior to BAK exposure significantly dampened levels of LC3-II (P < 0.05) and promoted a significant increase in cellular metabolic activity (P < 0.01) compared to BAK alone. Conclusions These results suggest lacritin protects cultured HCE cells stressed with BAK. Lacritin may have the potential to be used as a topical adjunctive therapy in eyes chronically exposed to BAK. PMID:24401093

  14. Quinone formation as a chemoprevention strategy for hybrid drugs: balancing cytotoxicity and cytoprotection.

    PubMed

    Dunlap, Tareisha; Chandrasena, R Esala P; Wang, Zhiqiang; Sinha, Vaishali; Wang, Zhican; Thatcher, Gregory R J

    2007-12-01

    Cellular defense mechanisms that respond to damage from oxidative and electrophilic stress, such as from quinones, represent a target for chemopreventive agents. Drugs bioactivated to quinones have the potential to activate antioxidant/electrophile responsive element (ARE) transcription of genes for cytoprotective phase 2 enzymes such as NAD(P)H-dependent quinone oxidoreductase (NQO1) but can also cause cellular damage. Two isomeric families of compounds were prepared, including the NO-NSAIDs (NO-donating nonsteroidal anti-inflammatory drugs) NCX 4040 and NCX 4016; one family was postulated to release a quinone methide on esterase bioactivation. The study of reactivity and GSH conjugation in model and cell systems confirmed the postulate. The quinone-forming family, including NCX 4040 and conisogenic bromides and mesylate, was rapidly bioactivated to a quinone, which gave activation of ARE and consequent induction of NQO1 in liver cells. Although the control family, including NCX 4016 and conisogenic bromides and mesylates, cannot form a quinone, ARE activation and NQO1 induction were observed, compatible with slower SN2 reactions with thiol sensor proteins, and consequent ARE-luciferase and NQO1 induction. Using a Chemoprevention Index estimate, the quinone-forming compounds suffered because of high cytoxicity and were more compatible with cancer therapy than chemoprevention. In the Comet assay, NCX 4040 was highly genotoxic relative to NCX 4016. There was no evidence that NO contributes to the observed biological activity and no evidence that NCX 4040 is an NO donor, instead, rapidly releasing NO3- and quinone. These results indicate a strategy for studying the quinone biological activity and reinforce the therapeutic attributes of NO-ASA through structural elements other than NO and ASA.

  15. Selective cytoprotective effect of histamine on doxorubicin-induced hepatic and cardiac toxicity in animal models

    PubMed Central

    Lamas, DJMartinel; Nicoud, MB; Sterle, HA; Carabajal, E; Tesan, F; Perazzo, JC; Cremaschi, GA; Rivera, ES; Medina, VA

    2015-01-01

    The aim of the present work was to evaluate the potential protective effect of histamine on Doxorubicin (Dox)-induced hepatic and cardiac toxicity in different rodent species and in a triple-negative breast tumor-bearing mice model. Male Sprague Dawley rats and Balb/c mice were divided into four groups: control (received saline), histamine (5 mg/kg for rats and 1 mg/kg for mice, daily subcutaneous injection starting 24 h before treatment with Dox), Dox (2 mg/kg, intraperitoneally injected three times a week for 2 weeks) and Dox+histamine (received both treatments). Tissue toxicity was evaluated by histopathological studies and oxidative stress and biochemical parameters. The combined effect of histamine and Dox was also investigated in vitro and in vivo in human MDA-MB-231 triple-negative breast cancer model. Heart and liver of Dox-treated animals displayed severe histological damage, loss of tissue weight, increased TBARS levels and DNA damage along with an augment in serum creatine kinase-myocardial band. Pretreatment with histamine prevented Dox-induced tissue events producing a significant preservation of the integrity of both rat and mouse myocardium and liver, through the reduction of Dox-induced oxidative stress and apoptosis. Histamine treatment preserved anti-tumor activity of Dox, exhibiting differential cytotoxicity and increasing the Dox-induced inhibition of breast tumor growth. Findings provide preclinical evidence indicating that histamine could be a promising candidate as a selective cytoprotective agent for the treatment of Dox-induced cardiac and hepatic toxicity, and encourage the translation to clinical practice. PMID:27551485

  16. Honokiol activates reactive oxygen species-mediated cytoprotective autophagy in human prostate cancer cells.

    PubMed

    Hahm, Eun-Ryeong; Sakao, Kozue; Singh, Shivendra V

    2014-09-01

    Honokiol (HNK), derived from the bark of an oriental medicinal plant (Magnolia officinalis), is a promising anticancer agent with preclinical in vitro (PC-3 and LNCaP cells) and in vivo (PC-3 xenografts) efficacy against prostate cancer. However, the mechanisms affecting anticancer response to HNK are not fully understood. Human (androgen-independent PC-3 and androgen-responsive LNCaP) and murine (Myc-CaP) prostate cancer cells, and PC-3 tumor xenografts were used for various assays. Autophagy was assessed by transmission electron microscopy, immunofluorescence (LC3 puncta), and immunoblotting (LC3BII detection). Cell viability was determined by trypan blue assay. Apoptosis was quantitated by DNA fragmentation detection and Annexin V/propidium iodide assay. Reactive oxygen species (ROS) were detected by electron paramagnetic resonance spectrometry and flow cytometric/microscopic analysis of MitoSOX red fluorescence. Exposure of PC-3, LNCaP, and Myc-CaP cells to pharmacologic doses of HNK resulted in autophagy induction. The PC-3 tumor xenografts from HNK-treated mice contained higher levels of LC3BII protein compared with control tumors. Cell viability inhibition and apoptosis induction resulting from HNK exposure were significantly augmented by pharmacological inhibition of autophagy using 3-methyladenine as well as RNA interference of autophagy regulator ATG5. HNK-mediated increase in levels of LC3BII protein was partially but markedly diminished in the presence of antioxidants, including N-acetylcysteine, polyethylene glycol-conjugated (PEG)-superoxide dismutase, and PEG-catalase. On the other hand, antioxidants had no impact on HNK-induced apoptosis. In conclusion, the present study demonstrates, for the first time, that HNK induces ROS-mediated cytoprotective autophagy in prostate cancer cells. © 2014 Wiley Periodicals, Inc.

  17. Myogenic differentiation induces taurine transporter in association with taurine-mediated cytoprotection in skeletal muscles.

    PubMed

    Uozumi, Yoriko; Ito, Takashi; Hoshino, Yuki; Mohri, Tomomi; Maeda, Makiko; Takahashi, Kyoko; Fujio, Yasushi; Azuma, Junichi

    2006-03-15

    Skeletal muscle homoeostasis is maintained by a variety of cytoprotective mechanisms. Since ablation of the TauT (taurine transporter) gene results in susceptibility to exercise-induced muscle weakness in vivo, it has been suggested that TauT is essential for skeletal muscle function. However, the regulatory mechanisms of TauT expression remain to be elucidated. In the present study, we demonstrated that TauT was up-regulated during myogenesis in C2C12 cells. Treatment with bFGF (basic fibroblast growth factor), which inhibited muscle differentiation, abrogated myogenic induction of TauT. The promoter activities of TauT were up-regulated during muscle differentiation in C2C12 cells. Database analyses identified an MEF2 (myocyte enhancer binding factor 2) consensus sequence at -844 in the rat TauT gene. Truncation of the promoter region containing the MEF2 site significantly reduced the promoter activity, demonstrating the functional importance of the MEF2 site. Electrophoretic mobility-shift assays confirmed that MEF2 bound to the MEF2 consensus sequence and that DNA-protein complex levels were increased during differentiation. Promoter analyses using mutated promoter-reporter plasmids demonstrated that this site was functional. Importantly, transfection with a MyoD expression vector markedly enhanced TauT promoter activity in the (non-myogenic) 10T1/2 cells. Moreover, co-transfection with an MEF2 expression vector augmented MyoD-induced TauT promoter activity, suggesting that MEF2 is required for full activation of TauT expression. Finally, we examined the effects of taurine on myotube atrophy to clarify the biological significance of the up-regulation of TauT, and demonstrated that taurine attenuated muscle atrophy induced by dexamethasone. TauT expression is regulated under the control of the myogenic programme, and we propose that this is the mechanism for taurine-mediated resistance to muscle atrophy.

  18. Relationship between energetic stress and pro-apoptotic/cytoprotective kinase mechanisms in intestinal preservation.

    PubMed

    Salehi, Payam; Walker, John; Madsen, Karen L; Sigurdson, Grant T; Strand, Berit L; Christensen, Bjørn E; Jewell, Laurence D; Churchill, Thomas A

    2007-06-01

    A recent study from our laboratory documented significant improvements in post-transplant viability in an experimental model of intestinal transplantation when a novel, nutrient-rich preservation solution was used during cold storage. The current study investigated the relationship between energetic/oxidative stress responses and fundamental kinase signaling events during the period of organ storage. This relationship may be a key factor contributing to improved graft viability after storage in a nutrient-rich preservation solution. Rat small intestine was harvested and flushed intraluminally with University of Wisconsin (UW) solution or an amino acid-rich (AA) solution as follows: Group 1, no luminal flush (clinical control); Group 2, luminal UW solution; Group 3, luminal AA solution. Energetics (ATP, total adenylates), oxidative stress (malondialdehyde), histology, and MAPK (P38, JNK, ERK)/AMPK/Caspase-3 were assessed throughout 12-hour cold storage. P38 and JNK were upregulated strongly in Group 2 after 1- and 12-hour storage. Group 3 exhibited a delayed activation and subsequent downregulation of these pre-apoptotic signals. Between 6 to 12 hours, a strong upregulation of ERK was observed in Group 3. AMPK downregulation correlated with a reduction in AMP/ATP ratio, ERK upregulation, and P38/JNK downregulation in Group 3. After 12-hour storage, histology indicated superior preservation of mucosal architecture in Group 3 tissues. A nutrient-rich preservation solution abrogates pre-apoptotic signaling (JNK and P38) and upregulates cytoprotective signals (ERK). Our data support the concept of a concerted effort facilitating cellular protection in response to ischemic stress.

  19. Control of absence seizures induced by the pathways connected to SRN in corticothalamic system.

    PubMed

    Hu, Bing; Guo, Daqing; Wang, Qingyun

    2015-06-01

    The cerebral cortex, thalamus and basal ganglia together form an important network in the brain, which is closely related to several nerve diseases, such as parkinson disease, epilepsy seizure and so on. Absence seizure can be characterized by 2-4 Hz oscillatory activity, and it can be induced by abnormal interactions between the cerebral cortex and thalamus. Many experimental results have also shown that basal ganglia are a key neural structure, which closely links the corticothalamic system in the brain. Presently, we use a corticothalamic-basal ganglia model to study which pathways in corticothalamic system can induce absence seizures and how these oscillatory activities can be controlled by projections from the substantia nigra pars reticulata (SNr) to the thalamic reticular nucleus (TRN) or the specific relay nuclei (SRN) of the thalamus. By tuning the projection strength of the pathway "Excitatory pyramidal cortex-SRN", "SRN-Excitatory pyramidal cortex" and "SRN-TRN" respectively, different firing states including absence seizures can appear. This indicates that absence seizures can be induced by tuning the connection strength of the considered pathway. In addition, typical absence epilepsy seizure state "spike-and-slow wave discharges" can be controlled by adjusting the activation level of the SNr as the pathways SNr-SRN and SNr-TRN open independently or together. Our results emphasize the importance of basal ganglia in controlling absence seizures in the corticothalamic system, and can provide a potential idea for the clinical treatment.

  20. Ventral Fronto-Temporal Pathway Supporting Cognitive Control of Episodic Memory Retrieval

    PubMed Central

    Barredo, Jennifer; Öztekin, Ilke; Badre, David

    2015-01-01

    Achieving our goals often requires guiding access to relevant information from memory. Such goal-directed retrieval requires interactions between systems supporting cognitive control, including ventrolateral prefrontal cortex (VLPFC), and those supporting declarative memory, such as the medial temporal lobes (MTL). However, the pathways by which VLPFC interacts with MTL during retrieval are underspecified. Prior neuroanatomical evidence suggests that a polysynaptic ventral fronto-temporal pathway may support VLPFC–MTL interactions. To test this hypothesis, human participants were scanned using fMRI during performance of a source-monitoring task. The strength of source information was varied via repetition during encoding. Single encoding events should produce a weaker memory trace, thus recovering source information about these items should demand greater cognitive control. Results demonstrated that cortical targets along the ventral path—anterior VLPFC, temporal pole, anterior parahippocampus, and hippocampus—exhibited increases in univariate BOLD response correlated with increases in controlled retrieval demand, independent of factors related to response selection. Further, a functional connectivity analysis indicated that these regions functionally couple and are distinguishable from a dorsal pathway related to response selection demands. These data support a ventral retrieval pathway linking PFC and MTL. PMID:24177990

  1. Improving fatty acids production by engineering dynamic pathway regulation and metabolic control

    PubMed Central

    Xu, Peng; Li, Lingyun; Zhang, Fuming; Stephanopoulos, Gregory; Koffas, Mattheos

    2014-01-01

    Global energy demand and environmental concerns have stimulated increasing efforts to produce carbon-neutral fuels directly from renewable resources. Microbially derived aliphatic hydrocarbons, the petroleum-replica fuels, have emerged as promising alternatives to meet this goal. However, engineering metabolic pathways with high productivity and yield requires dynamic redistribution of cellular resources and optimal control of pathway expression. Here we report a genetically encoded metabolic switch that enables dynamic regulation of fatty acids (FA) biosynthesis in Escherichia coli. The engineered strains were able to dynamically compensate the critical enzymes involved in the supply and consumption of malonyl-CoA and efficiently redirect carbon flux toward FA biosynthesis. Implementation of this metabolic control resulted in an oscillatory malonyl-CoA pattern and a balanced metabolism between cell growth and product formation, yielding 15.7- and 2.1-fold improvement in FA titer compared with the wild-type strain and the strain carrying the uncontrolled metabolic pathway. This study provides a new paradigm in metabolic engineering to control and optimize metabolic pathways facilitating the high-yield production of other malonyl-CoA–derived compounds. PMID:25049420

  2. The Secret Life of NAD+: An Old Metabolite Controlling New Metabolic Signaling Pathways

    PubMed Central

    Houtkooper, Riekelt H.; Cantó, Carles; Wanders, Ronald J.; Auwerx, Johan

    2010-01-01

    A century after the identification of a coenzymatic activity for NAD+, NAD+ metabolism has come into the spotlight again due to the potential therapeutic relevance of a set of enzymes whose activity is tightly regulated by the balance between the oxidized and reduced forms of this metabolite. In fact, the actions of NAD+ have been extended from being an oxidoreductase cofactor for single enzymatic activities to acting as substrate for a wide range of proteins. These include NAD+-dependent protein deacetylases, poly(ADP-ribose) polymerases, and transcription factors that affect a large array of cellular functions. Through these effects, NAD+ provides a direct link between the cellular redox status and the control of signaling and transcriptional events. Of particular interest within the metabolic/endocrine arena are the recent results, which indicate that the regulation of these NAD+-dependent pathways may have a major contribution to oxidative metabolism and life span extension. In this review, we will provide an integrated view on: 1) the pathways that control NAD+ production and cycling, as well as its cellular compartmentalization; 2) the signaling and transcriptional pathways controlled by NAD+; and 3) novel data that show how modulation of NAD+-producing and -consuming pathways have a major physiological impact and hold promise for the prevention and treatment of metabolic disease. PMID:20007326

  3. Improving fatty acids production by engineering dynamic pathway regulation and metabolic control.

    PubMed

    Xu, Peng; Li, Lingyun; Zhang, Fuming; Stephanopoulos, Gregory; Koffas, Mattheos

    2014-08-05

    Global energy demand and environmental concerns have stimulated increasing efforts to produce carbon-neutral fuels directly from renewable resources. Microbially derived aliphatic hydrocarbons, the petroleum-replica fuels, have emerged as promising alternatives to meet this goal. However, engineering metabolic pathways with high productivity and yield requires dynamic redistribution of cellular resources and optimal control of pathway expression. Here we report a genetically encoded metabolic switch that enables dynamic regulation of fatty acids (FA) biosynthesis in Escherichia coli. The engineered strains were able to dynamically compensate the critical enzymes involved in the supply and consumption of malonyl-CoA and efficiently redirect carbon flux toward FA biosynthesis. Implementation of this metabolic control resulted in an oscillatory malonyl-CoA pattern and a balanced metabolism between cell growth and product formation, yielding 15.7- and 2.1-fold improvement in FA titer compared with the wild-type strain and the strain carrying the uncontrolled metabolic pathway. This study provides a new paradigm in metabolic engineering to control and optimize metabolic pathways facilitating the high-yield production of other malonyl-CoA-derived compounds.

  4. Nucleic acid sensing and innate immunity: signaling pathways controlling viral pathogenesis and autoimmunity

    PubMed Central

    Ahlers, Laura R. H.; Goodman, Alan G.

    2016-01-01

    Innate immunity refers to the body’s initial response to curb infection upon exposure to invading organisms. While the detection of pathogen-associated molecules is an ancient form of host defense, if dysfunctional, autoimmune disease may result. The innate immune response during pathogenic infection is initiated through the activation of receptors recognizing conserved molecular patterns, such as nucleic acids from a virus’ genome or replicative cycle. Additionally, the host’s own nucleic acids are capable of activating an immune response. Therefore, it follows that the nucleic acid-sensing pathways must be tightly controlled to avoid an autoimmune response from recognition of self, yet still be unimpeded to respond to viral infections. In this review, we will describe the nucleic acid sensing pathways and how they respond to virus infection. Moreover, we will discuss autoimmune diseases that develop when these pathways fail to signal properly and identify knowledge gaps that are prime for interrogation. PMID:27857881

  5. TFAP2C controls hormone response in breast cancer cells through multiple pathways of estrogen signaling.

    PubMed

    Woodfield, George W; Horan, Annamarie D; Chen, Yizhen; Weigel, Ronald J

    2007-09-15

    Breast cancers expressing estrogen receptor-alpha (ERalpha) are associated with a favorable biology and are more likely to respond to hormonal therapy. In addition to ERalpha, other pathways of estrogen response have been identified including ERbeta and GPR30, a membrane receptor for estrogen, and the key mechanisms regulating expression of ERs and hormone response remain controversial. Herein, we show that TFAP2C is the key regulator of hormone responsiveness in breast carcinoma cells through the control of multiple pathways of estrogen signaling. TFAP2C regulates the expression of ERalpha directly by binding to the ERalpha promoter and indirectly via regulation of FoxM1. In so doing, TFAP2C controls the expression of ERalpha target genes, including pS2, MYB, and RERG. Furthermore, TFAP2C controlled the expression of GPR30. In distinct contrast, TFAP2A, a related factor expressed in breast cancer, was not involved in estrogen-mediated pathways but regulated expression of genes controlling cell cycle arrest and apoptosis including p21(CIP1) and IGFBP-3. Knockdown of TFAP2C abrogated the mitogenic response to estrogen exposure and decreased hormone-responsive tumor growth of breast cancer xenografts. We conclude that TFAP2C is a central control gene of hormone response and is a novel therapeutic target in the design of new drug treatments for breast cancer.

  6. The cytoprotective effects of oleoylethanolamide in insulin-secreting cells do not require activation of GPR119.

    PubMed

    Stone, Virginia M; Dhayal, Shalinee; Smith, David M; Lenaghan, Carol; Brocklehurst, Katy J; Morgan, Noel G

    2012-04-01

    β-cells express a range of fatty acid-responsive G protein-coupled receptors, including GPR119, which regulates insulin secretion and is seen as a potential therapeutic target in type 2 diabetes. The long-chain unsaturated fatty acid derivative oleoylethanolamide (OEA) is an endogenous agonist of GPR119 and, under certain conditions, some long-chain unsaturated fatty acids can promote β-cell cytoprotection. It is not known, however, if OEA is cytoprotective in β-cells. The present study has examined this and determined whether GPR119 is involved. Clonal rat insulin-secreting cell lines, BRIN-BD11 or INS-1E, were exposed to fatty acids complexed with BSA. cAMP levels, insulin release and cell viability were measured. Protein expression was studied by Western blotting and receptor expression by RT-PCR. GPR119 was expressed in both BRIN-BD11 and INS-1E cells and OEA was cytoprotective in these cells. However, cytoprotection was not reproduced by any of a range of selective, synthetic ligands of GPR119. The cytoprotective response to OEA was lost during exposure to inhibitors of fatty acid amide hydrolase (FAAH) suggesting that OEA per se is not the cytoprotective species but that release of free oleate is required. Similar data were obtained with anandamide, which was cytoprotective only under conditions favouring release of free arachidonate. Activation of GPR119 is not required to mediate the cytoprotective actions of OEA in BRIN-BD11 or INS-1E cells. Rather, OEA is internalised and subjected to hydrolysis by FAAH to release free oleate, which then mediates the cytoprotection. © 2011 The Authors. British Journal of Pharmacology © 2011 The British Pharmacological Society.

  7. The cytoprotective effects of oleoylethanolamide in insulin-secreting cells do not require activation of GPR119

    PubMed Central

    Stone, Virginia M; Dhayal, Shalinee; Smith, David M; Lenaghan, Carol; Brocklehurst, Katy J; Morgan, Noel G

    2012-01-01

    BACKGROUND AND PURPOSE β-cells express a range of fatty acid-responsive G protein-coupled receptors, including GPR119, which regulates insulin secretion and is seen as a potential therapeutic target in type 2 diabetes. The long-chain unsaturated fatty acid derivative oleoylethanolamide (OEA) is an endogenous agonist of GPR119 and, under certain conditions, some long-chain unsaturated fatty acids can promote β-cell cytoprotection. It is not known, however, if OEA is cytoprotective in β-cells. The present study has examined this and determined whether GPR119 is involved. METHODS Clonal rat insulin-secreting cell lines, BRIN-BD11 or INS-1E, were exposed to fatty acids complexed with BSA. cAMP levels, insulin release and cell viability were measured. Protein expression was studied by Western blotting and receptor expression by RT-PCR. KEY RESULTS GPR119 was expressed in both BRIN-BD11 and INS-1E cells and OEA was cytoprotective in these cells. However, cytoprotection was not reproduced by any of a range of selective, synthetic ligands of GPR119. The cytoprotective response to OEA was lost during exposure to inhibitors of fatty acid amide hydrolase (FAAH) suggesting that OEA per se is not the cytoprotective species but that release of free oleate is required. Similar data were obtained with anandamide, which was cytoprotective only under conditions favouring release of free arachidonate. CONCLUSIONS AND IMPLICATIONS Activation of GPR119 is not required to mediate the cytoprotective actions of OEA in BRIN-BD11 or INS-1E cells. Rather, OEA is internalised and subjected to hydrolysis by FAAH to release free oleate, which then mediates the cytoprotection. PMID:22029844

  8. Signal transduction pathways, intrinsic regulators, and the control of cell fate choice

    PubMed Central

    Fossett, Nancy

    2012-01-01

    Background Information regarding changes in organismal status is transmitted to the stem cell regulatory machinery by a limited number of signal transduction pathways. Consequently, these pathways derive their functional specificity through interactions with stem cell intrinsic master regulators, notably transcription factors. Identifying the molecular underpinnings of these interactions is critical to understanding stem cell function. Scope of review This review focuses on studies in Drosophila that identify the gene regulatory basis for interactions between three different signal transduction pathways and an intrinsic master transcriptional regulator in the context of hematopoietic stem-like cell fate choice. Specifically, the interface between the GATA:FOG regulatory complex and the JAK/STAT, BMP, and Hedgehog pathways is examined. Major conclusions The GATA:FOG complex coordinates information transmitted by at least three different signal transduction pathways as a means to control stem-like cell fate choice. This illustrates emerging principles concerning regulation of stem cell function and describes a gene regulatory link between changes in organismal status and stem cell response. General significance The Drosophila model system offers a powerful approach to identify the molecular basis of how stem cells receive, interpret, and then respond to changes in organismal status. PMID:22705942

  9. Dynamics and Design Principles of a Basic Regulatory Architecture Controlling Metabolic Pathways

    PubMed Central

    Jolly, Emmitt R; DeRisi, Joe; Li, Hao

    2008-01-01

    The dynamic features of a genetic network's response to environmental fluctuations represent essential functional specifications and thus may constrain the possible choices of network architecture and kinetic parameters. To explore the connection between dynamics and network design, we have analyzed a general regulatory architecture that is commonly found in many metabolic pathways. Such architecture is characterized by a dual control mechanism, with end product feedback inhibition and transcriptional regulation mediated by an intermediate metabolite. As a case study, we measured with high temporal resolution the induction profiles of the enzymes in the leucine biosynthetic pathway in response to leucine depletion, using an automated system for monitoring protein expression levels in single cells. All the genes in the pathway are known to be coregulated by the same transcription factors, but we observed drastically different dynamic responses for enzymes upstream and immediately downstream of the key control point—the intermediate metabolite α-isopropylmalate (αIPM), which couples metabolic activity to transcriptional regulation. Analysis based on genetic perturbations suggests that the observed dynamics are due to differential regulation by the leucine branch-specific transcription factor Leu3, and that the downstream enzymes are strictly controlled and highly expressed only when αIPM is available. These observations allow us to build a simplified mathematical model that accounts for the observed dynamics and can correctly predict the pathway's response to new perturbations. Our model also suggests that transient dynamics and steady state can be separately tuned and that the high induction levels of the downstream enzymes are necessary for fast leucine recovery. It is likely that principles emerging from this work can reveal how gene regulation has evolved to optimize performance in other metabolic pathways with similar architecture. PMID:18563967

  10. Automated genome annotation and pathway identification using the KEGG Orthology (KO) as a controlled vocabulary.

    PubMed

    Mao, Xizeng; Cai, Tao; Olyarchuk, John G; Wei, Liping

    2005-10-01

    High-throughput technologies such as DNA sequencing and microarrays have created the need for automated annotation of large sets of genes, including whole genomes, and automated identification of pathways. Ontologies, such as the popular Gene Ontology (GO), provide a common controlled vocabulary for these types of automated analysis. Yet, while GO offers tremendous value, it also has certain limitations such as the lack of direct association with pathways. We demonstrated the use of the KEGG Orthology (KO), part of the KEGG suite of resources, as an alternative controlled vocabulary for automated annotation and pathway identification. We developed a KO-Based Annotation System (KOBAS) that can automatically annotate a set of sequences with KO terms and identify both the most frequent and the statistically significantly enriched pathways. Results from both whole genome and microarray gene cluster annotations with KOBAS are comparable and complementary to known annotations. KOBAS is a freely available stand-alone Python program that can contribute significantly to genome annotation and microarray analysis.

  11. A Golgi-based KDELR-dependent signalling pathway controls extracellular matrix degradation.

    PubMed

    Ruggiero, Carmen; Fragassi, Giorgia; Grossi, Mauro; Picciani, Benedetta; Di Martino, Rosaria; Capitani, Mirco; Buccione, Roberto; Luini, Alberto; Sallese, Michele

    2015-02-20

    We recently identified an endomembrane-based signalling cascade that is activated by the KDEL receptor (KDELR) on the Golgi complex. At the Golgi, the KDELR acts as a traffic sensor (presumably via binding to chaperones that leave the ER) and triggers signalling pathways that balance membrane fluxes between ER and Golgi. One such pathway relies on Gq and Src. Here, we examine if KDELR might control other cellular modules through this pathway. Given the central role of Src in extracellular matrix (ECM) degradation, we investigated the impact of the KDELR-Src pathway on the ability of cancer cells to degrade the ECM. We find that activation of the KDELR controls ECM degradation by increasing the number of the degradative structures known as invadopodia. The KDELR induces Src activation at the invadopodia and leads to phosphorylation of the Src substrates cortactin and ASAP1, which are required for basal and KDELR-stimulated ECM degradation. This study furthers our understanding of the regulatory circuitry underlying invadopodia-dependent ECM degradation, a key phase in metastases formation and invasive growth.

  12. Genetic control of the alternative pathway of complement in humans and age-related macular degeneration.

    PubMed

    Hecker, Laura A; Edwards, Albert O; Ryu, Euijung; Tosakulwong, Nirubol; Baratz, Keith H; Brown, William L; Charbel Issa, Peter; Scholl, Hendrik P; Pollok-Kopp, Beatrix; Schmid-Kubista, Katharina E; Bailey, Kent R; Oppermann, Martin

    2010-01-01

    Activation of the alternative pathway of complement is implicated in common neurodegenerative diseases including age-related macular degeneration (AMD). We explored the impact of common variation in genes encoding proteins of the alternative pathway on complement activation in human blood and in AMD. Genetic variation across the genes encoding complement factor H (CFH), factor B (CFB) and component 3 (C3) was determined. The influence of common haplotypes defining transcriptional and translational units on complement activation in blood was determined in a quantitative genomic association study. Individual haplotypes in CFH and CFB were associated with distinct and novel effects on plasma levels of precursors, regulators and activation products of the alternative pathway of complement in human blood. Further, genetic variation in CFH thought to influence cell surface regulation of complement did not alter plasma complement levels in human blood. Plasma markers of chronic activation (split-products Ba and C3d) and an activating enzyme (factor D) were elevated in AMD subjects. Most of the elevation in AMD was accounted for by the genetic variation controlling complement activation in human blood. Activation of the alternative pathway of complement in blood is under genetic control and increases with age. The genetic variation associated with increased activation of complement in human blood also increased the risk of AMD. Our data are consistent with a disease model in which genetic variation in the complement system increases the risk of AMD by a combination of systemic complement activation and abnormal regulation of complement activation in local tissues.

  13. Quantum control via a genetic algorithm of the field ionization pathway of a Rydberg electron

    NASA Astrophysics Data System (ADS)

    Gregoric, Vincent C.; Kang, Xinyue; Liu, Zhimin Cheryl; Rowley, Zoe A.; Carroll, Thomas J.; Noel, Michael W.

    2017-08-01

    Quantum control of the pathway along which a Rydberg electron field ionizes is experimentally and computationally demonstrated. Selective field ionization is typically done with a slowly rising electric field pulse. The (1/n*)4 scaling of the classical ionization threshold leads to a rough mapping between arrival time of the electron signal and principal quantum number of the Rydberg electron. This is complicated by the many avoided level crossings that the electron must traverse on the way to ionization, which in general leads to broadening of the time-resolved field ionization signal. In order to control the ionization pathway, thus directing the signal to the desired arrival time, a perturbing electric field produced by an arbitrary wave-form generator is added to a slowly rising electric field. A genetic algorithm evolves the perturbing field in an effort to achieve the target time-resolved field ionization signal.

  14. Cytoprotection against Hypoxic and/or MPP+ Injury: Effect of δ–Opioid Receptor Activation on Caspase 3

    PubMed Central

    Xu, Yuan; Zhi, Feng; Shao, Naiyuan; Wang, Rong; Yang, Yilin; Xia, Ying

    2016-01-01

    The pathological changes of Parkinson’s disease (PD) are, at least partially, associated with the dysregulation of PTEN-induced putative kinase 1 (PINK1) and caspase 3. Since hypoxic and neurotoxic insults are underlying causes of PD, and since δ-opioid receptor (DOR) is neuroprotective against hypoxic/ischemic insults, we sought to determine whether DOR activation could protect the cells from damage induced by hypoxia and/or MPP+ by regulating PINK1 and caspase 3 expressions. We exposed PC12 cells to either severe hypoxia (0.5%–1% O2) for 24–48 h or to MPP+ at different concentrations (0.5, 1, 2 mM) and then detected the levels of PINK1 and cleaved caspase 3. Both hypoxia and MPP+ reduced cell viability, progressively suppressed the expression of PINK1 and increased the cleaved caspase 3. DOR activation using UFP-512, effectively protected the cells from hypoxia and/or MPP+ induced injury, reversed the reduction in PINK1 protein and significantly attenuated the increase in the cleaved caspase 3. On the other hand, the application of DOR antagonist, naltrindole, greatly decreased cell viability and increased cleaved caspase 3. These findings suggest that DOR is cytoprotective against both hypoxia and MPP+ through the regulation of PINK1 and caspase 3 pathways. PMID:27517901

  15. IRE1-RACK1 axis orchestrates ER stress preconditioning-elicited cytoprotection from ischemia/reperfusion injury in liver.

    PubMed

    Liu, Dong; Liu, Xing; Zhou, Ti; Yao, William; Zhao, Jun; Zheng, Zhigang; Jiang, Wei; Wang, Fengsong; Aikhionbare, Felix O; Hill, Donald L; Emmett, Nerimah; Guo, Zhen; Wang, Dongmei; Yao, Xuebiao; Chen, Yong

    2016-04-01

    Endoplasmic reticulum (ER) stress is involved in ischemic preconditioning that protects various organs from ischemia/reperfusion (I/R) injury. We established an in vivo ER stress preconditioning model in which tunicamycin was injected into rats before hepatic I/R. The hepatic I/R injury, demonstrated by serum aminotransferase level and the ultra-structure of the liver, was alleviated by administration of tunicamycin, which induced ER stress in rat liver by activating inositol-requiring enzyme 1 (IRE1) and upregulating 78 kDa glucose-regulated protein (GRP78). The proteomic identification for IRE1 binders revealed interaction and cooperation among receptor for activated C kinase 1 (RACK1), phosphorylated AMPK, and IRE1 under ER stress conditions in a spatiotemporal manner. Furthermore, in vitro ER stress preconditioning was induced by thapsigargin and tunicamycin in L02 and HepG2 cells. Surprisingly, BCL2 was found to be phosphorylated by IRE1 under ER stress conditions to prevent apoptotic process by activation of autophagy. In conclusion, ER stress preconditioning protects against hepatic I/R injury, which is orchestrated by IRE1-RACK1 axis through the activation of BCL2. Our findings provide novel insights into the molecular pathways underlying ER stress preconditioning-elicited cytoprotective effect against hepatic I/R injury. © The Author (2015). Published by Oxford University Press on behalf of Journal of Molecular Cell Biology, IBCB, SIBS, CAS. All rights reserved.

  16. The cytoprotective effect of Rumex Aquaticus Herba extract against hydrogen peroxide-induced oxidative stress in AGS cells.

    PubMed

    Cho, Eun Jeong; Um, Seung In; Han, Jeong Hoon; Kim, Byeonghee; Han, Sang Beom; Jeong, Ji Hoon; Kim, Hak Rim; Kim, Inkyeom; Whang, Wan Kyun; Lee, Eunhwa; Sohn, Uy Dong

    2016-12-01

    The Rumex Aquaticus Herba extract containing quercetin-3-β-D-glucuronopyranoside (ECQ) has been reported to exhibit various pharmacological activities, including anti-inflammatory and anti-oxidative effects. This plant has been traditionally used for the treatment of diarrhea, disinfestation, edema and jaundice, and as an antipyretic drug. The aim of the present study was to investigate the ability of ECQ to protect against oxidative damage and to determine its signaling mechanism in AGS cells. The protein expressions of heme oxygenase-1 (HO-1) and nuclear factor-erythroid 2 related factor 2 (Nrf2) were measured by Western blots. Cell viability was measured by MTT assay. Intracellular reactive oxygen species (ROS) levels were measured using 2',7'-dichlorofluorescein diacetate. Glutathione peroxidase levels were measured using kits. The protein expressions of HO-1 and its upstream mediator, Nrf2, increased after ECQ treatment. The HO-1 inhibitor, ZnPP, repressed the protective effect of ECQ on H2O2-induced cell damage. We found that LY294002, a specific PI3 K/Akt inhibitor, suppressed ECQ-induced HO-1 expression. ECQ significantly attenuated H2O2-induced cytotoxicity and ROS generation. Also, ECQ enhanced the antioxidant enzyme activities of glutathione peroxidase. These results suggest that ECQ exerts a cytoprotective effect against H2O2-induced oxidative stress by upregulation of Nrf2/HO-1 via the PI3 K/Akt pathway.

  17. Improvement of anti-tumor activity of photodynamic therapy through inhibition of cytoprotective mechanism in tumor cells

    NASA Astrophysics Data System (ADS)

    Nowis, Dominika; Szokalska, Angelika; Makowski, Marcin; Winiarska, Magdalena; Golab, Jakub

    2009-06-01

    Photodynamic therapy (PDT) leads to oxidative damage of cellular macromolecules, including numerous proteins that undergo multiple modifications such as fragmentation, cross-linking and carbonylation that result in protein unfolding and aggregation. Several mechanisms are involved in the protective responses to PDT that include activation of transcription factors, heat shock proteins, antioxidant enzymes and antiapoptotic pathways. Identification of these cytoprotective mechanisms might result in the design of more effective combination strategies to improve the antitumor efficacy of PDT. By using various molecular biology approaches, including microarray-based technologies we have identified genes that are up-regulated following PDT. Subsequent experiments revealed that some of these gene products can become targets for the combined therapeutic regimens encompassing PDT and selective small-molecule inhibitors. These include superoxide dismutase (SOD-2), cyclooxygenase 2 (COX-2), heme oxygenase 1 (HO-1), and proteins engaged in signaling endoplasmatic reticulum (ER) stress and unfolded protein response (UPR). Since a major mechanism for elimination of carbonylated proteins is their degradation by proteasomes, we hypothesized that a combination of PDT with proteasome inhibitors might lead to accumulation of carbonylated proteins in ER, aggravated ER stress and potentiated cytotoxicity towards tumor cells. Indeed, we observed that incubation of tumor cells with three different proteasome inhibitors, including bortezomib, MG132 and PSI gave increased accumulation of carbonylated and ubiquitinated proteins in PDT-treated cells. Proteasome inhibitors effectively sensitized tumor cells to PDT-mediated cytotoxicity and augmented antitumor effects of PDT in vivo.

  18. Cytoprotective effects of Glycyrrhizae radix extract and its active component liquiritigenin against cadmium-induced toxicity (effects on bad translocation and cytochrome c-mediated PARP cleavage).

    PubMed

    Kim, Sang Chan; Byun, Sung Hui; Yang, Chae Ha; Kim, Chul Young; Kim, Jin Woong; Kim, Sang Geon

    2004-05-03

    Glycyrrhizae radix has been popularly used as one of the oldest and most frequently employed botanicals in herbal medicine in Asian countries, and currently occupies an important place in food products. Cadmium (Cd) induces both apoptotic and non-apoptotic cell death, in which alterations in cellular sulfhydryls participate. In the present study, we determined the effects of G. radix extract (GRE) and its representative active components on cell death induced by Cd and explored the mechanistic basis of cytoprotective effects of G. radix. Incubation of H4IIE cells with GRE inhibited cell death induced by 10 microM Cd. Also, GRE effectively blocked Cd (1 microM)-induced cell death potentiated by buthionine sulfoximine (BSO) without restoration of cellular GSH. GRE prevented both apoptotic and non-apoptotic cell injury induced by Cd (10 microM) or Cd (0.3-1 microM) + BSO. Inhibition of Cd-induced cell injury by pretreatment of cells with GRE suggested that the cytoprotective effect result from alterations in the levels of the protein(s) responsible for cell viability. GRE inhibited mitochondrial Bad translocation by Cd or CD+BSO, and caused restoration of mitochondrial Bcl(xL) and cytochrome c levels. Cd-induced poly(ADP-ribose)polymerase cleavage in control cells or in cells deprived of sulfhydryls was prevented by GRE treatment. Among the major components present in GRE, liquiritigenin, but not liquiritin, isoliquiritigenin or glycyrrhizin, exerted cytoprotective effect. These results demonstrated that GRE blocked Cd-induced cell death by inhibiting the apoptotic processes involving translocation of Bad into mitochondria, decreases in mitochondrial Bcl(xL) and cytochrome c, and poly(ADP-ribose)polymerase cleavage.

  19. IL-10 restricts dendritic cell (DC) growth at the monocyte-to-monocyte-derived DC interface by disrupting anti-apoptotic and cytoprotective autophagic molecular machinery.

    PubMed

    Martin, Carla; Espaillat, Mel Pilar; Santiago-Schwarz, Frances

    2015-12-01

    An evolving premise is that cytoprotective autophagy responses are essential to monocyte-macrophage differentiation. Whether autophagy functions similarly during the monocyte-to-dendritic cell (DC) transition is unclear. IL-10, which induces apoptosis in maturing human DCs, has been shown to inhibit starvation-induced autophagy in murine macrophage cell lines. Based on the strict requirement that Bcl-2-mediated anti-apoptotic processes are implemented during the monocyte-to-DC transition, we hypothesized that cytoprotective autophagy responses also operate at the monocyte-DC interface and that IL-10 inhibits both anti-apoptotic and cytoprotective autophagy responses at this critical juncture. In support of our premise, we show that levels of anti-apoptotic Bcl-2 and autophagy-associated LC3 and Beclin-1 proteins are coincidentally upregulated during the monocyte-to-DC transition. Autophagy was substantiated by increased autophagosome visualization after bafilomycin treatment. Moreover, the autophagy inhibitor 3-MA restricted DC differentiation by prompting apoptosis. IL-10 implemented apoptosis that was coincidentally associated with reduced levels of Bcl-2 and widespread disruption of the autophagic flux. During peak apoptosis, IL-10 produced the death of newly committed DCs. However, cells surviving the IL-10 apoptotic schedule were highly phagocytic macrophage-like cells displaying reduced capacity to stimulate allogeneic naïve T cells in a mixed leukocyte reaction, increased levels of LC3, and mature autophagosomes. Thus, IL-10's negative control of DC-driven adaptive immunity at the monocyte-DC interface includes disruption of coordinately regulated molecular networks involved in pro-survival autophagy and anti-apoptotic responses.

  20. Metabolic Pathway Signatures Associated with Urinary Metabolite Biomarkers Differentiate Bladder Cancer Patients from Healthy Controls

    PubMed Central

    Kim, Won Tae; Yun, Seok Joong; Yan, Chunri; Jeong, Pildu; Kim, Ye Hwan; Lee, Il-Seok; Kang, Ho-Won; Park, Sunghyouk; Moon, Sung-Kwon; Choi, Yung-Hyun; Choi, Young Deuk; Kim, Isaac Yi

    2016-01-01

    Purpose Our previous high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry study identified bladder cancer (BCA)-specific urine metabolites, including carnitine, acylcarnitines, and melatonin. The objective of the current study was to determine which metabolic pathways are perturbed in BCA, based on our previously identified urinary metabolome. Materials and Methods A total of 135 primary BCA samples and 26 control tissue samples from healthy volunteers were analyzed. The association between specific urinary metabolites and their related encoding genes was analyzed. Results Significant alterations in the carnitine-acylcarnitine and tryptophan metabolic pathways were detected in urine specimens from BCA patients compared to those of healthy controls. The expression of eight genes involved in the carnitine-acylcarnitine metabolic pathway (CPT1A, CPT1B, CPT1C, CPT2, SLC25A20, and CRAT) or tryptophan metabolism (TPH1 and IDO1) was assessed by RT-PCR in our BCA cohort (n=135). CPT1B, CPT1C, SLC25A20, CRAT, TPH1, and IOD1 were significantly downregulated in tumor tissues compared to normal bladder tissues (p<0.05 all) of patients with non-muscle invasive BCA, whereas CPT1B, CPT1C, CRAT, and TPH1 were downregulated in those with muscle invasive BCA (p<0.05), with no changes in IDO1 expression. Conclusion Alterations in the expression of genes associated with the carnitine-acylcarnitine and tryptophan metabolic pathways, which were the most perturbed pathways in BCA, were determined. PMID:27189278

  1. Gradual implementation of the meiotic recombination program via checkpoint pathways controlled by global DSB levels.

    PubMed

    Joshi, Neeraj; Brown, M Scott; Bishop, Douglas K; Börner, G Valentin

    2015-03-05

    During meiosis, Spo11-induced double-strand breaks (DSBs) are processed into crossovers, ensuring segregation of homologous chromosomes (homologs). Meiotic DSB processing entails 5' end resection and preferred strand exchange with the homolog rather than the sister chromatid (homolog bias). In many organisms, DSBs appear gradually along the genome. Here we report unexpected effects of global DSB levels on local recombination events. Early-occurring, low-abundance "scout" DSBs lack homolog bias. Their resection and interhomolog processing are controlled by the conserved checkpoint proteins Tel1(ATM) kinase and Pch2(TRIP13) ATPase. Processing pathways controlled by Mec1(ATR) kinase take over these functions only above a distinct DSB threshold, resulting in progressive strengthening of the homolog bias. We conclude that Tel1(ATM)/Pch2 and Mec1(ATR) DNA damage response pathways are sequentially activated during wild-type meiosis because of their distinct sensitivities to global DSB levels. Moreover, relative DSB order controls the DSB repair pathway choice and, ultimately, recombination outcome.

  2. A conserved quality-control pathway that mediates degradation of unassembled ribosomal proteins

    PubMed Central

    Sung, Min-Kyung; Porras-Yakushi, Tanya R; Reitsma, Justin M; Huber, Ferdinand M; Sweredoski, Michael J; Hoelz, André; Hess, Sonja; Deshaies, Raymond J

    2016-01-01

    Overproduced yeast ribosomal protein (RP) Rpl26 fails to assemble into ribosomes and is degraded in the nucleus/nucleolus by a ubiquitin-proteasome system quality control pathway comprising the E2 enzymes Ubc4/Ubc5 and the ubiquitin ligase Tom1. tom1 cells show reduced ubiquitination of multiple RPs, exceptional accumulation of detergent-insoluble proteins including multiple RPs, and hypersensitivity to imbalances in production of RPs and rRNA, indicative of a profound perturbation to proteostasis. Tom1 directly ubiquitinates unassembled RPs primarily via residues that are concealed in mature ribosomes. Together, these data point to an important role for Tom1 in normal physiology and prompt us to refer to this pathway as ERISQ, for excess ribosomal protein quality control. A similar pathway, mediated by the Tom1 homolog Huwe1, restricts accumulation of overexpressed hRpl26 in human cells. We propose that ERISQ is a key element of the quality control machinery that sustains protein homeostasis and cellular fitness in eukaryotes. DOI: http://dx.doi.org/10.7554/eLife.19105.001 PMID:27552055

  3. Disentangling puberty: novel neuroendocrine pathways and mechanisms for the control of mammalian puberty.

    PubMed

    Avendaño, M S; Vazquez, M J; Tena-Sempere, M

    2017-08-30

    Puberty is a complex developmental event, controlled by sophisticated regulatory networks that integrate peripheral and internal cues and impinge at the brain centers driving the reproductive axis. The tempo of puberty is genetically determined but is also sensitive to numerous modifiers, from metabolic and sex steroid signals to environmental factors. Recent epidemiological evidence suggests that the onset of puberty is advancing in humans, through as yet unknown mechanisms. In fact, while much knowledge has been gleaned recently on the mechanisms responsible for the control of mammalian puberty, fundamental questions regarding the intimate molecular and neuroendocrine pathways responsible for the precise timing of puberty and its deviations remain unsolved. By combining data from suitable model species and humans, we aim to provide a comprehensive summary of our current understanding of the neuroendocrine mechanisms governing puberty, with particular focus on its central regulatory pathways, underlying molecular basis and mechanisms for metabolic control. A comprehensive MEDLINE search of articles published mostly from 2003 to 2017 has been carried out. Data from cellular and animal models (including our own results) as well as clinical studies focusing on the pathophysiology of puberty in mammals were considered and cross-referenced with terms related with central neuroendocrine mechanisms, metabolic control and epigenetic/miRNA regulation. Studies conducted during the last decade have revealed the essential role of novel central neuroendocrine pathways in the control of puberty, with a prominent role of kisspeptins in the precise regulation of the pubertal activation of GnRH neurosecretory activity. In addition, different transmitters, including neurokinin-B (NKB) and, possibly, melanocortins, have been shown to interplay with kisspeptins in tuning puberty onset. Alike, recent studies have documented the role of epigenetic mechanisms, involving mainly

  4. [Binding of epirubicin to human plasma protein and erythrocytes: interaction with the cytoprotective amifostine].

    PubMed

    Pernkopf, I; Tesch, G; Dempe, K; Kletzl, H; Schüller, J; Czejka, M

    1996-11-01

    The in vitro binding rate of epirubicin (EPR) to different plasma proteins, control serum, red blood cells and whole blood was investigated without and with the cytoprotective agent amifostine. The binding rate of EPR to plasma proteins fractions and red blood cells dependend on the concentration of the matrix components. EPR was bound more than 90% to human serum alpha-globulin (alpha-HSG), to human serum albumine (HSA) and human serum beta-globuline (beta-HSG) at 80 to 90%, in the case of human serum gamma-globulin (gamma-HSG) the binding rate amounted 75%. The binding rate of EPR to RBCs in whole blood samples reached 38%. Within the observed concentration range of proteins (1-40 micrograms/ml, depending on the protein concentration) AMI caused a reduction of the protein-bound amount of EPR in the range from 2 to 19% of HSA, 4 to 20 in the case of beta-HSG, 2 to 32% in the case of alpha-HSG and 17 to 21% for gamma-HSG. In the whole blood samples the binding of EPR to proteins dropped from 45 to 32% and RBC-partitioning from 38 to 32%. Two compounds with free thiol groups, cystein and glutathione, were compared with AMI in regard to lowering the binding rate of EPR to HSA: the effect was exactly in the same order of magnitude: -17% for AMI, -21.0% for cystein and -20.8% for glutahion (p < 0.002). For a negative control, cystin and phenylalanin were tested, too: both compounds showed no influence on the protein binding of EPR: 63.8% binding rate in the control group, 65.2% in the presence of cystin and 64.6% in the presence of phenylalanin (statistically not significant). The present results indicate, that binding of EPR to serum proteins is reduced in the presence of AMI by interaction of the thiol-group with the protein and that the thiophosphoric ester bond in the test solution must cleave rapidly.

  5. Observing and Controlling the Folding Pathway of DNA Origami at the Nanoscale.

    PubMed

    Wah, Jonathan Lee Tin; David, Christophe; Rudiuk, Sergii; Baigl, Damien; Estevez-Torres, André

    2016-02-23

    DNA origami is a powerful method to fold DNA into rationally designed nanostructures that holds great promise for bionanotechnology. However, the folding mechanism has yet to be fully resolved, principally due to a lack of data with single molecule resolution. To address this issue, we have investigated in detail, using atomic force microscopy, the morphological evolution of hundreds of individual rectangular origamis in solution as a function of temperature. Significant structural changes were observed between 65 and 55 °C both for folding and melting, and six structural intermediates were identified. Under standard conditions, folding was initiated at the edges of the rectangle and progressed toward the center. Melting occurred through the reverse pathway until the structures were significantly disrupted but ended through a different pathway involving out-of-equilibrium chainlike structures. Increasing the relative concentration of center to edge staples dramatically modified the folding pathway to a mechanism progressing from the center toward the edges. These results indicate that the folding pathway is determined by thermodynamics and suggest a way of controlling it.

  6. Low direct cytotoxicity and cytoprotective effects of nitric oxide releasing indomethacin.

    PubMed

    Tomisato, Wataru; Tanaka, Ken-Ichiro; Tsutsumi, Shinji; Hoshino, Tatsuya; Yokomizo, Kazumi; Suzuki, Keitarou; Katsu, Takashi; Mizushima, Tohru; Mizushima, Tohru

    2005-10-01

    Nitric oxide (NO) releasing non-steroidal anti-inflammatory drugs (NSAIDs) have shown a marked reduction of gastrointestinal side effects and we here examined the cytotoxicity of NCX 530 (NO-indomethacin). Under conditions where indomethacin clearly induced both necrosis and apoptosis, NCX 530 induced neither. NCX 530 protected cells from celecoxib-induced necrosis and apoptosis. NCX 530 partially suppressed celecoxib-dependent membrane permeabilization and an inhibitor for guanylate cyclase suppressed the cytoprotective effect of NCX 530 against celecoxib. In vivo, NCX 530 alone produced fewer gastric lesions in rats than did indomethacin. A combination of the oral administration of celecoxib together with the intraperitoneal administration of indomethacin, but not of NCX 530, clearly resulted in the production of gastric lesions. The low direct cytotoxicity and the cytoprotective effect of NCX 530 observed in vitro may also act in vivo, thus ensuring that NCX 530 is safe for use on the gastric mucosa.

  7. Role of mucosal prostaglandins and DNA synthesis in gastric cytoprotection by luminal epidermal growth factor.

    PubMed Central

    Konturek, S J; Brzozowski, T; Piastucki, I; Dembinski, A; Radecki, T; Dembinska-Kiec, A; Zmuda, A; Gregory, H

    1981-01-01

    This study compares the effect of epidermal growth factor and prostaglandins (PGE2 or PGI2), applied topically to gastric mucosa, on gastric secretion and formation of ASA-induced gastric ulcerations in rats. Epidermal growth factor given topically in non-antisecretory doses prevented dose-dependently the formation of ASA-induced ulcers without affecting prostaglandin generation but with a significant rise in DNA synthesis in the oxyntic mucosa. The anti-ulcer effect of topical prostaglandins was also accompanied by an increase in DNA synthesis. This study indicates that topical epidermal growth factor, like PGE2 or PGI2, is cytoprotective and that this cytoprotection is not mediated by the inhibition of gastric secretion or prostaglandin formation but related to the increase in DNA synthesis in oxyntic mucosa. PMID:7030877

  8. Antiradical and cytoprotective activities of several C-geranyl-substituted flavanones from Paulownia tomentosa fruit.

    PubMed

    Zima, Ales; Hosek, Jan; Treml, Jakub; Muselík, Jan; Suchý, Pavel; Prazanová, Gabriela; Lopes, Ana; Zemlicka, Milan

    2010-08-31

    Antiradical and cytoprotective activities of several flavanones isolated from Paulownia tomentosa (Thunb.) Steud. (Scrophulariaceae) have been evaluated using different in vitro and in vivo methods. The capacity of flavanones to scavenge radicals was measured in vitro by means of DPPH and ABTS assays, the inhibition of hydroxyl radicals produced in Fenton reactions, FRAP, scavenging superoxide radicals using enzymatic and nonenzymatic assays and the inhibition of peroxynitrite-induced nitration of tyrosine. The in vivo testing involved measuring the cytoprotective effect of chosen flavanones against alloxan-induced diabetes in mice. The activity of tested compounds was expressed either as a Trolox® equivalent or was compared with rutin or morine as known antioxidant compounds. The highest activity in most tests was observed for diplacone and 3´-O-methyl-5´-hydroxydiplacone, and the structure vs. the antioxidant activity relationship of geranyl or prenyl-substituted flavonoids with different substitutions at the B and C ring was discussed.

  9. Cytoprotective alginate/polydopamine core/shell microcapsules in microbial encapsulation.

    PubMed

    Kim, Beom Jin; Park, Taegyun; Moon, Hee Chul; Park, So-Young; Hong, Daewha; Ko, Eun Hyea; Kim, Ji Yup; Hong, Jong Wook; Han, Sang Woo; Kim, Yang-Gyun; Choi, Insung S

    2014-12-22

    Chemical encapsulation of microbes in threedimensional polymeric microcapsules promises various applications, such as cell therapy and biosensors, and provides a basic platform for studying microbial communications. However, the cytoprotection of microbes in the microcapsules against external aggressors has been a major challenge in the field of microbial microencapsulation, because ionotropic hydrogels widely used for microencapsulation swell uncontrollably, and are physicochemically labile. Herein, we developed a simple polydopamine coating for obtaining cytoprotective capability of the alginate capsule that encapsulated Saccharomyces cerevisiae. The resulting alginate/ polydopamine core/shell capsule was mechanically tough, prevented gel swelling and cell leakage, and increased resistance against enzymatic attack and UV-C irradiation. We believe that this multifunctional core/shell structure will provide a practical tool for manipulating microorganisms inside the microcapsules. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Gastric cytoprotection of the non-steroidal anti-inflammatory sesquiterpene, beta-caryophyllene.

    PubMed

    Tambe, Y; Tsujiuchi, H; Honda, G; Ikeshiro, Y; Tanaka, S

    1996-10-01

    The gastric cytoprotective effect of beta-caryophyllene, an anti-inflammatory sesquiterpene, was investigated in rats. The oral administration of beta-caryophyllene to rats significantly inhibited gastric mucosal injuries induced by necrotizing agents such as absolute ethanol and 0.6 N HCl, although it failed to prevent water immersion stress- and indomethacin-induced gastric lesions. In addition, this compound hardly affected the secretion of gastric acid and pepsin. Thus, beta-caryophyllene elicited anti-inflammatory effects without any indication of gastric mucosal damage typical of non-steroidal anti-inflammatory agents. Furthermore, this compound manifested cytoprotective effects, rendering the two-dimensional efficacious beta-caryophyllene to be a clinically safe and potentially useful agent.

  11. Approaches to gastrointestinal cytoprotection: from isolated cells, via animal experiments to healthy human subjects and patients with different gastrointestinal disorders.

    PubMed

    Mózsik, Gyula; Szabó, Imre L; Czimmer, József

    2011-01-01

    Our clinical observations proved that the the duodenal ulcer in patients healed without any inhibition of gastric acid secretion (1965), and the healing rates of atropine vs cimetidine vs Carbenoxolone were equal and superior to that of placebo in randomized, prospective and multiclinical study of DU patients (1978). The phenomenon of gastric cytoprotection was defined by André Robert in rats (1979). The essential point of this phenomenon is that the prostaglandins prevent the chemical-induced gastric mucosal damage without affecting gastric acid secretion, this being originally suggested as a reaction specific to prostaglandins. Since then gastrointestinal cytoprotection has been shown with various agents (anticholinergic agents, H(2)RA, growth factors, body protecting compound, BPC) and retinoids in animals; the latter differing from the actions of vitamin A. In examining the various components of gastrointestinal cytoprotection , different studies have performed in isolated cells, stable cell lines, animal experiments, healthy human subjects, in patients chronic gastric and duodenal ulcers, and with different gastrointestinal disorders. Our attention has focused on the effects of cytoprotective agents on cellular viability, mitochondrial and DNA damage, oxygen free radicals, natural antioxidant systems, mucosal biochemistry, vascular events, gastrointestinal mucosal protection as well as in their prevention of different human diseases. This paper gives an overview on the different approaches for the exploring gastrointestinal cytoprotection (at the level of isolated cells, animal experiments, healthy human beings and patients with different gastrointestinal disorders). It has been indicated that the gastric cytoprotection exists in animals, human healthy subjects, patients with different gastrointestinal disorders. The our human observation in patients with duodenal ulcer healed without any changes of gastric acid secretion, there were no significant

  12. Nurse-Driven Clinical Pathway for Inpatient Asthma: A Randomized Controlled Trial.

    PubMed

    Pound, Catherine M; Gelt, Victoria; Akiki, Salwa; Eady, Kaylee; Moreau, Katherine; Momoli, Franco; Murchison, Barbara; Zemek, Roger; Mulholland, Brett; Kovesi, Tom

    2017-04-01

    We examined the impact of a nurse-driven clinical pathway on length of stay (LOS) for children hospitalized with asthma. We conducted a randomized controlled trial involving children hospitalized with asthma. Nurses of children in the intervention group weaned salbutamol frequency using an asthma scoring tool, whereas physicians weaned salbutamol frequency for the control group patients as per standard care. The primary outcome was LOS in hours. Secondary outcomes included number of salbutamol treatments administered, ICU transfers, unplanned medical visits postdischarge, and stakeholders' pathway satisfaction. Research staff, investigators, and statisticians were blinded to group assignment, except for research assistants enrolling participants. Qualitative interviews were done to assess acceptability of intervention by physicians, nurses, residents, and patients. We recruited 113 participants (mean age 4.9 years, 62% boys) between May 2012 and September 2015. Median LOS was 49 hours (21-243 hours) and 47 hours (22-188 hours) (P = .11), for the control and intervention groups, respectively. A post hoc analysis designed to deal with highly skewed LOS data resulted in a relative 18% (95% confidence interval 0.68-0.99) LOS reduction for the intervention group. There was no difference in secondary outcomes. No significant adverse events resulted from the intervention. The 14 participants included in the qualitative component reported a positive experience with the pathway. This nurse-driven pathway led to increased efficiency as evidenced by a modest LOS reduction. It allowed for care standardization, improved utilization of nursing resources, and high stakeholder satisfaction. Copyright © 2017 by the American Academy of Pediatrics.

  13. Roles of Hippo signaling pathway in size control of organ regeneration.

    PubMed

    Hayashi, Shinichi; Yokoyama, Hitoshi; Tamura, Koji

    2015-05-01

    Animals have an intrinsic regeneration ability for injured tissues and organs. Species that have high regeneration ability such as newts can regenerate an organ with exactly the same size and shape as those of the original one. It has been unclear how a regenerating organ grows and ceases growth at an appropriate size. Organ size control in regeneration is seen in various organs of various species that have high regeneration ability. In animal species that do not have sufficient regeneration ability, a wound heals (the injury is closed, but lost parts are not regenerated), but an organ cannot be restored to its original size. On the other hand, perturbation of regeneration sometimes results in oversized or extra structures. In this sense, organ size control plays essential roles in proper regeneration. In this article, we introduce the concept of size control in organ regeneration regulated by the Hippo signaling pathway. We focused on the transcriptional regulator Yap, which shuttles between the nuclei and cytoplasm to exert a regulatory function in a context-dependent manner. The Yap-mediated Hippo pathway is thought to sense cell density, extracellular matrix (ECM) contact and cell position and to regulate gene expression for control of organ size. This mechanism can reasonably explain size control of organ regeneration.

  14. Differential cytoprotection by glycine against oxidant damage to proximal tubule cells.

    PubMed

    Sogabe, K; Roeser, N F; Venkatachalam, M A; Weinberg, J M

    1996-09-01

    Tert-butyl hydroperoxide (tBHP) injured freshly isolated proximal tubules in an Fe-dependent fashion that was ameliorated by a lipophilic antioxidant, diphenyl-p-phenylenediamine (DPPD), but was only minimally affected by glycine. Menadione-induced injury was Fe-independent and was unaffected by DPPD, but was strongly blocked by glycine. Fe was highly toxic when intracellular loading was facilitated by concomitant treatment with hydroxyquinoline (HQ). This toxicity was blocked by DPPD or chelating the Fe, but not by glycine. All of the lesions were characterized by severe depletion of glutathione and other soluble thiols. Menadione induced large increases in protein associated with the Triton-insoluble cytoskeleton and decreases in protein thiol content, consistent with extensive cross linking, but did not increase thiobarbituric acid reactive substances (TBARS). tBHP and HQ + Fe had either no effect or only moderate, delayed effects on cytoskeletal proteins, but induced substantial increases of TBARS. Glycine did not the alter changes in cytoskeletal proteins, thiols, or TBARS produced by any of the agents. Protection against tBHP toxicity by deferoxamine and DPPD was accompanied by substantial suppression of TBARS accumulation. Superimposition of hypoxia during tBHP exposure reduced TBARS accumulation and restored cytoprotective activity to glycine. Thus, in contrast to its consistently strong cytoprotection against a number of other insults, glycine is only variably cytoprotective against oxidant lesions in freshly isolated proximal tubules. Extensive oxidative crosslinking of proteins is compatible with maintenance of glycine cytoprotection against lethal membrane damage. Fe-induced injury to proximal tubules associated with lipid peroxidation as manifested by TBARS formation is a relatively glycine-insensitive insult.

  15. Radioprotective and cytoprotective activity of Tinospora cordifolia stem enriched extract containing cordifolioside-A

    PubMed Central

    Patel, Arti; Bigoniya, Papiya; Singh, Chandra Shekhar; Patel, Narayan Singh

    2013-01-01

    Objectives: The present study was undertaken to evaluate the radioprotective and cytoprotective potential of cordifolioside-A, a primary active constituent of n-butanol fraction of Tinospora Cordifolia (NBTC) against 4 Gy-γ radiation in mice and cyclophosphamide induced genotoxicity. Materials and Methods: Presence of cordifolioside-A in NBTC stem ethanolic extract was confirmed by high performance thin layer chromatography (HPTLC) analysis. Radioprotective activity was evaluated at 80 and 120 mg/kg, intraperitoneal (i.p.) dose of NBTC administered 15 days prior to whole body radiation exposure by observing survival rate, change in body weight, hematology, spleen colony forming unit (CFU), and micronucleus (MN) expression. Cytoprotective activity of NBTC was evaluated at 5, 10, and 15 mg/ml concentrations on Allium cepa root meristem growth against cyclophosphamide. Results: HPTLC analysis of standard cordifolioside A, and NBTC confirmed the presence of cordifolioside-A in NBTC with the retention factor value of 0.86. Administration of NBTC (120 mg/kg, i.p.) produced significant protection against radiation in terms of increased survival rate, body weight retention, hematological parameters, spleen CFU assay (P < 0.01), and decreased MN expression (P < 0.01). Cytoprotectivity was observed maximally at 10 mg/ml NBTC concentration with significant increase in root growth (P < 0.01), non-toxic mitotic index (MI) (65.9%) and lesser chromosomal aberrations (15.4%). NBTC at 10 mg/ml concentration showed very few C-anaphase compared to aberrations like fragmentation, C-anaphase, multipolarity and sticky chromosome in cyclophosphamide alone. Conclusion: The results suggest that enriched NBTC containing cordifolioside-A has a potential in vivo radioprotective effect as well as in vitro cytoprotective activity. PMID:23833365

  16. The cytoprotective role of taurine in exercise-induced muscle injury.

    PubMed

    Dawson, R; Biasetti, M; Messina, S; Dominy, J

    2002-06-01

    Intense exercise is thought to increase oxidative stress and damage muscle tissue. Taurine is present in high concentration in skeletal muscle and may play a role in cellular defenses against free radical-mediated damage. The aim of this study was to determine if manipulating muscle levels of taurine would alter markers of free radical damage after exercise-induced injury. Adult male Sprague-Dawley rats were supplemented via the drinking water with either 3% (w/v) taurine (n = 10) or the competitive taurine transport inhibitor, beta-alanine (n = 10), for one month. Controls (n = 20) drank tap water containing 0.02% taurine and all rats were placed on a taurine free diet. All the rats except one group of sedentary controls (n = 10) were subjected to 90 minutes of downhill treadmill running. Markers of cellular injury and free radical damage were determined along with tissue amino acid content. The 3% taurine treatment raised plasma levels about 2-fold and 3% beta-alanine reduced plasma taurine levels about 50%. Taurine supplementation (TS) significantly increased plasma glutamate levels in exercised rats. Exercise reduced plasma methionine levels and taurine prevented its decline. Taurine supplementation increased muscle taurine content significantly in all muscles except the soleus. beta-alanine decreased muscle taurine content about 50% in all the muscles examined. Lipid peroxidation (TBARS) was significantly increased by exercise in the extensor digitorium longus (EDL) and gastrocnemius (GAST) muscles. Both taurine and beta-alanine completely blocked the increase in TBARs in the EDL, but had no effect in the GAST. Muscle content of the cytosolic enzyme, lactate dehydrogenase (LDH) was significantly decreased by exercise in the GAST muscle and this effect was attenuated by both taurine and beta-alanine. Muscle myeloperoxidase (MPO) activity was significantly elevated in the gastrocnemius muscle, but diet had no effect. MPO activity was significantly increased by

  17. Synthesis of novel tetrahydrobenzazepine derivatives and their cytoprotective effect on human lymphocytes.

    PubMed

    Simic, Milena R; Stankovic, Miroslava; Mandic, Boris M; Tesevic, Vele V; Savic, Vladimir M

    2015-02-01

    Cytoprotective compounds such as amifostine play an important role in chemo- and radiotherapy due to their ability to reduce the side effects of these treatments. Our work was initiated with the intention to design, synthesise and test a new class of heterocyclic compounds that would have an antioxidative profile with the potential to be further developed as cytoprotective agents. The design was based on the privileged tetrahydrobenzazepine scaffold found in many natural products with a wide range of biological properties. This structure was further functionalised with moieties known to possess antioxidative features such as tertiary amine and styrene double bond. A series of eight tetrahydrobenzazepine derivatives of isoquinoline, 3,4-dihydro-β-carboline and pyridine were synthesised employing the Heck reaction as a key transformation. Some of the prepared compounds were tested for their in vitro effects on chromosome aberrations in peripheral human lymphocytes using the cytochalasin-B blocked micronucleus (MN) assay. Three tetrahydrobenzoazepine derivatives showed significant cytoprotective properties, comparable or even better to those of the radioprotective agent amifostine. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Oncostatic-Cytoprotective Effect of Melatonin and Other Bioactive Molecules: A Common Target in Mitochondrial Respiration

    PubMed Central

    Pacini, Nicola; Borziani, Fabio

    2016-01-01

    For several years, oncostatic and antiproliferative properties, as well as thoses of cell death induction through 5-methoxy-N-acetiltryptamine or melatonin treatment, have been known. Paradoxically, its remarkable scavenger, cytoprotective and anti-apoptotic characteristics in neurodegeneration models, such as Alzheimer’s disease and Parkinson’s disease are known too. Analogous results have been confirmed by a large literature to be associated to the use of many other bioactive molecules such as resveratrol, tocopherol derivatives or vitamin E and others. It is interesting to note that the two opposite situations, namely the neoplastic pathology and the neurodegeneration, are characterized by deep alterations of the metabolome, of mitochondrial function and of oxygen consumption, so that the oncostatic and cytoprotective action can find a potential rationalization because of the different metabolic and mitochondrial situations, and in the effect that these molecules exercise on the mitochondrial function. In this review we discuss historical and general aspects of melatonin, relations between cancers and the metabolome and between neurodegeneration and the metabolome, and the possible effects of melatonin and of other bioactive molecules on metabolic and mitochondrial dynamics. Finally, we suggest a common general mechanism as responsible for the oncostatic/cytoprotective effect of melatonin and of other molecules examined. PMID:26959015

  19. Spin Trapping and Cytoprotective Properties of Fluorinated Amphiphilic Carrier Conjugates of Cyclic versus Linear Nitrones

    PubMed Central

    Durand, Grégory; Prosak, Robert A.; Han, Yongbin; Ortial, Stéphanie; Rockenbauer, Antal; Pucci, Bernard; Villamena, Frederick A.

    2009-01-01

    Nitrone spin traps have been employed as pharmacological agent against neurodegenerative diseases and ischemia-reperfusion induced injury. The structure-activity relationship was explored for the two types of nitrones, i.e., cyclic (DMPO) and linear (PBN), which are conjugated to a fluorinated amphiphilic carrier (FAC) for their cytoprotective properties against hydrogen peroxide (H2O2), 3-morpholinosynonimine hydrochloride (SIN-1) and 4-hydroxynonenal (HNE) induced cell death on bovine aortic endothelial cells. The compound FAMPO was synthesized and characterized, and its physical-chemical and spin trapping properties were explored. Cytotoxicity and cytoprotective properties of various nitrones either conjugated and non-conjugated to FAC (i.e., AMPO, FAMPO, PBN and FAPBN) were assessed using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium (MTT) reduction assay. Results show that of all the nitrones tested, FAPBN is the most protective against H2O2, but FAMPO and to a lesser extent its unconjugated form, AMPO, are more protective against SIN-1 induced cytotoxicity. However, none of the nitrones used protect the cells from HNE-induced cell death. The difference in the cytoprotective properties observed between the cyclic and linear nitrones may arise from the differences in their intrinsic antioxidant properties and localization in the cell. PMID:19678661

  20. Antioxidant, cytoprotective and antibacterial effects of Sea buckthorn (Hippophae rhamnoides L.) leaves.

    PubMed

    Upadhyay, Nitin K; Kumar, M S Yogendra; Gupta, Asheesh

    2010-12-01

    The present study was carried out to investigate the antioxidant, cytoprotective and antibacterial effects of aqueous and hydroalcoholic extracts of Hippophae rhamnoides L. (Sea buckthorn) (SBT) leaves by using various in vitro systems and analysis of marker compounds by reverse phase-high performance liquid chromatography (RP-HPLC). The chemical composition of the leaf extracts was quantified by colorimetric reaction in terms of total phenol and flavonoids contents. Further, some of its bioactive phenolic constituents, such as quercetin-3-O-galactoside, quercetin-3-O-glucoside, kaempferol and isorhamnetin were also quantified in both SBT leaf extracts by RP-HPLC. The SBT leaf extracts exhibited potent antioxidant activity determined by 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. Further, both extracts were observed to have cytoprotective activity against hydrogen peroxide and hypoxanthine-xanthine oxidase induced damage to BHK-21 cell line. The SBT leaf extracts showed growth inhibiting effect against Bacillus cereus, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus faecalis. These observations suggest that aqueous and hydroalcoholic extracts of Sea buckthorn leaves have marked antioxidant, cytoprotective and antibacterial activities.

  1. Cytoprotective effects of fucoidan, an algae-derived polysaccharide on 5-fluorouracil-treated dendritic cells.

    PubMed

    Jeong, Bo-Eun; Ko, Eun-Ju; Joo, Hong-Gu

    2012-05-01

    Although chemotherapeutic anticancer agents are effective, they also attack normal immune cells due to a lack of selectivity. 5-Fluorouracil (5-FU) is a representative anticancer agent that induces immunosuppression in cancer patients as a side effect. Fucoidan is an algae-derived sulfated polysaccharide that has recently been recognized as a hematopoietic mobilizer and immunomodulator. In this study, we investigated the cytoprotective effect of fucoidan on dendritic cells (DCs) against 5-FU-induced cellular damage. Several kinds of assays including flow cytometric analysis demonstrated the cytoprotective efficacy of fucoidan. In addition, fucoidan increased the expression of immune-related surface markers on and the alloproliferative capacity of DCs exposed to 5-FU. For investigating action mechanism, the expression levels of apoptosis-related molecules were measured. Taken together, the results of this study suggest that fucoidan, a marine-derived polysaccharide, has cytoprotective effects on DCs, the most potent antigen-presenting cell type, against 5-FU-induced cellular damage. These results provide valuable information to use fucoidan as an immunostimulatory agent for the chemotherapy of cancer patients.

  2. Spray-dried Eudragit® L100 microparticles containing ferulic acid: Formulation, in vitro cytoprotection and in vivo anti-platelet effect.

    PubMed

    Nadal, Jessica Mendes; Gomes, Mona Lisa Simionatto; Borsato, Débora Maria; Almeida, Martinha Antunes; Barboza, Fernanda Malaquias; Zawadzki, Sônia Faria; Kanunfre, Carla Cristine; Farago, Paulo Vitor; Zanin, Sandra Maria Warumby

    2016-07-01

    This paper aimed to obtain new spray-dried microparticles containing ferulic acid (FA) prepared by using a methacrylic polymer (Eudragit® L100). Microparticles were intended for oral use in order to provide a controlled release, and improved in vitro and in vivo biological effects. FA-loaded Eudragit® L100 microparticles were obtained by spray-drying. Physicochemical properties, in vitro cell-based effects, and in vivo platelet aggregation were investigated. FA-loaded Eudragit® L100 microparticles were successfully prepared by spray-drying. Formulations showed suitable encapsulation efficiency, i.e. close to 100%. Microparticles were of spherical and almost-spherical shape with a smooth surface and a mean diameter between 2 and 3μm. Fourier-transformed infrared spectra demonstrated no chemical bond between FA and polymer. X-ray diffraction and differential scanning calorimetry analyses indicated that microencapsulation led to drug amorphization. FA-loaded microparticles showed a slower dissolution rate than pure drug. The chosen formulation demonstrated higher in vitro cytoprotection, anti-inflammatory and immunomodulatory potential and also improved in vivo anti-platelet effect. These results support an experimental basis for the use of FA spray-dried microparticles as a feasible oral drug delivery carrier for the controlled release of FA and improved cytoprotective and anti-platelet effects.

  3. Parallel pathways from motor and somatosensory cortex for controlling whisker movements in mice

    PubMed Central

    Sreenivasan, Varun; Karmakar, Kajari; Rijli, Filippo M; Petersen, Carl C H

    2015-01-01

    Mice can gather tactile sensory information by actively moving their whiskers to palpate objects in their immediate surroundings. Whisker sensory perception therefore requires integration of sensory and motor information, which occurs prominently in the neocortex. The signalling pathways from the neocortex for controlling whisker movements are currently poorly understood in mice. Here, we delineate two pathways, one originating from primary whisker somatosensory cortex (wS1) and the other from whisker motor cortex (wM1), that control qualitatively distinct movements of contralateral whiskers. Optogenetic stimulation of wS1 drove retraction of contralateral whiskers while stimulation of wM1 drove rhythmic whisker protraction. To map brainstem pathways connecting these cortical areas to whisker motor neurons, we used a combination of anterograde tracing using adenoassociated virus injected into neocortex and retrograde tracing using monosynaptic rabies virus injected into whisker muscles. Our data are consistent with wS1 driving whisker retraction by exciting glutamatergic premotor neurons in the rostral spinal trigeminal interpolaris nucleus, which in turn activate the motor neurons innervating the extrinsic retractor muscle nasolabialis. The rhythmic whisker protraction evoked by wM1 stimulation might be driven by excitation of excitatory and inhibitory premotor neurons in the brainstem reticular formation innervating both intrinsic and extrinsic muscles. Our data therefore begin to unravel the neuronal circuits linking the neocortex to whisker motor neurons. PMID:25476605

  4. A proposed model for the flowering signaling pathway of sugarcane under photoperiodic control.

    PubMed

    Coelho, C P; Costa Netto, A P; Colasanti, J; Chalfun-Júnior, A

    2013-04-25

    Molecular analysis of floral induction in Arabidopsis has identified several flowering time genes related to 4 response networks defined by the autonomous, gibberellin, photoperiod, and vernalization pathways. Although grass flowering processes include ancestral functions shared by both mono- and dicots, they have developed their own mechanisms to transmit floral induction signals. Despite its high production capacity and its important role in biofuel production, almost no information is available about the flowering process in sugarcane. We searched the Sugarcane Expressed Sequence Tags database to look for elements of the flowering signaling pathway under photoperiodic control. Sequences showing significant similarity to flowering time genes of other species were clustered, annotated, and analyzed for conserved domains. Multiple alignments comparing the sequences found in the sugarcane database and those from other species were performed and their phylogenetic relationship assessed using the MEGA 4.0 software. Electronic Northerns were run with Cluster and TreeView programs, allowing us to identify putative members of the photoperiod-controlled flowering pathway of sugarcane.

  5. Adipocyte Metabolic Pathways Regulated by Diet Control the Female Germline Stem Cell Lineage in Drosophila melanogaster.

    PubMed

    Matsuoka, Shinya; Armstrong, Alissa R; Sampson, Leesa L; Laws, Kaitlin M; Drummond-Barbosa, Daniela

    2017-06-01

    Nutrients affect adult stem cells through complex mechanisms involving multiple organs. Adipocytes are highly sensitive to diet and have key metabolic roles, and obesity increases the risk for many cancers. How diet-regulated adipocyte metabolic pathways influence normal stem cell lineages, however, remains unclear. Drosophila melanogaster has highly conserved adipocyte metabolism and a well-characterized female germline stem cell (GSC) lineage response to diet. Here, we conducted an isobaric tags for relative and absolute quantification (iTRAQ) proteomic analysis to identify diet-regulated adipocyte metabolic pathways that control the female GSC lineage. On a rich (relative to poor) diet, adipocyte Hexokinase-C and metabolic enzymes involved in pyruvate/acetyl-CoA production are upregulated, promoting a shift of glucose metabolism toward macromolecule biosynthesis. Adipocyte-specific knockdown shows that these enzymes support early GSC progeny survival. Further, enzymes catalyzing fatty acid oxidation and phosphatidylethanolamine synthesis in adipocytes promote GSC maintenance, whereas lipid and iron transport from adipocytes controls vitellogenesis and GSC number, respectively. These results show a functional relationship between specific metabolic pathways in adipocytes and distinct processes in the GSC lineage, suggesting the adipocyte metabolism-stem cell link as an important area of investigation in other stem cell systems. Copyright © 2017 by the Genetics Society of America.

  6. Parallel pathways from motor and somatosensory cortex for controlling whisker movements in mice.

    PubMed

    Sreenivasan, Varun; Karmakar, Kajari; Rijli, Filippo M; Petersen, Carl C H

    2015-02-01

    Mice can gather tactile sensory information by actively moving their whiskers to palpate objects in their immediate surroundings. Whisker sensory perception therefore requires integration of sensory and motor information, which occurs prominently in the neocortex. The signalling pathways from the neocortex for controlling whisker movements are currently poorly understood in mice. Here, we delineate two pathways, one originating from primary whisker somatosensory cortex (wS1) and the other from whisker motor cortex (wM1), that control qualitatively distinct movements of contralateral whiskers. Optogenetic stimulation of wS1 drove retraction of contralateral whiskers while stimulation of wM1 drove rhythmic whisker protraction. To map brainstem pathways connecting these cortical areas to whisker motor neurons, we used a combination of anterograde tracing using adenoassociated virus injected into neocortex and retrograde tracing using monosynaptic rabies virus injected into whisker muscles. Our data are consistent with wS1 driving whisker retraction by exciting glutamatergic premotor neurons in the rostral spinal trigeminal interpolaris nucleus, which in turn activate the motor neurons innervating the extrinsic retractor muscle nasolabialis. The rhythmic whisker protraction evoked by wM1 stimulation might be driven by excitation of excitatory and inhibitory premotor neurons in the brainstem reticular formation innervating both intrinsic and extrinsic muscles. Our data therefore begin to unravel the neuronal circuits linking the neocortex to whisker motor neurons.

  7. Mechanism-oriented controllability of intracellular quantum dots formation: the role of glutathione metabolic pathway.

    PubMed

    Li, Yong; Cui, Ran; Zhang, Peng; Chen, Bei-Bei; Tian, Zhi-Quan; Li, Li; Hu, Bin; Pang, Dai-Wen; Xie, Zhi-Xiong

    2013-03-26

    Microbial cells have shown a great potential to biosynthesize inorganic nanoparticles within their orderly regulated intracellular environment. However, very little is known about the mechanism of nanoparticle biosynthesis. Therefore, it is difficult to control intracellular synthesis through the manipulation of biological processes. Here, we present a mechanism-oriented strategy for controlling the biosynthesis of fluorescent CdSe quantum dots (QDs) by means of metabolic engineering in yeast cells. Using genetic techniques, we demonstrated that the glutathione metabolic pathway controls the intracellular CdSe QD formation. Inspired from this mechanism, the controllability of CdSe QD yield was realized through engineering the glutathione metabolism in genetically modified yeast cells. The yeast cells were homogeneously transformed into more efficient cell-factories at the single-cell level, providing a specific way to direct the cellular metabolism toward CdSe QD formation. This work could provide the foundation for the future development of nanomaterial biosynthesis.

  8. Physical Property Control on the Cellular Uptake Pathway and Spatial Distribution of Nanoparticles in Cells.

    PubMed

    Ahn, Sungsook; Seo, Eunseok; Kim, Ki Hean; Lee, Sang Joon

    2015-06-01

    Nanoparticles have been developed in broad biomedical research in terms of effective cellular interactions to treat and visualize diseased cells. Considering the charge and polar functional groups of proteins that are embedded in cellular membranes, charged nanoparticles have been strategically developed to enhance electrostatic cellular interactions. In this study, we show that cellular uptake efficiency, pathway, and spatial distribution of gold nanoparticles in a cell are significantly modulated based on the surface condition of gold nanoparticles and human cancer cells that were tuned by controlling the pH of the medium and by introducing an electron beam. Cellular uptake efficiency is increased when electrostatic attraction is induced between the cells and the gold nanoparticles. Cell surface modification changes the cellular uptake pathways of the gold nanoparticles and concentrates the gold nanoparticles at the membrane region. Surface modification of the gold nanoparticles also contributes to deep penetration and homogeneous spatial distributions in a cell.

  9. Optical switching of electric charge transfer pathways in porphyrin: a light-controlled nanoscale current router.

    PubMed

    Thanopulos, Ioannis; Paspalakis, Emmanuel; Yannopapas, Vassilios

    2008-11-05

    We introduce a novel molecular junction based on a thiol-functionalized porphyrin derivative with two almost energetically degenerate equilibrium configurations. We show that each equilibrium structure defines a pathway of maximal electric charge transfer through the molecular junction and that these two conduction pathways are spatially orthogonal. We further demonstrate computationally how to switch between the two equilibrium structures of the compound by coherent light. The optical switching mechanism is presented in the relevant configuration subspace of the compound, and the corresponding potential and electric dipole surfaces are obtained by ab initio methods. The laser-induced isomerization takes place in two steps in tandem, while each step is induced by a two-photon process. The effect of metallic electrodes on the electromagnetic irradiation driving the optical switching is also investigated. Our study demonstrates the potential for using thiol-functionalized porphyrin derivatives for the development of a light-controlled nanoscale current router.

  10. Transcriptional regulators in the Hippo signaling pathway control organ growth in Xenopus tadpole tail regeneration.

    PubMed

    Hayashi, Shinichi; Ochi, Haruki; Ogino, Hajime; Kawasumi, Aiko; Kamei, Yasuhiro; Tamura, Koji; Yokoyama, Hitoshi

    2014-12-01

    The size and shape of tissues are tightly controlled by synchronized processes among cells and tissues to produce an integrated organ. The Hippo signaling pathway controls both cell proliferation and apoptosis by dual signal-transduction states regulated through a repressive kinase cascade. Yap1 and Tead, transcriptional regulators that act downstream of the Hippo signaling kinase cascade, have essential roles in regulating cell proliferation. In amphibian limb or tail regeneration, the local tissue outgrowth terminates when the correct size is reached, suggesting that organ size is strictly controlled during epimorphic organ-level regeneration. We recently demonstrated that Yap1 is required for the regeneration of Xenopus tadpole limb buds (Hayashi et al., 2014, Dev. Biol. 388, 57-67), but the molecular link between the Hippo pathway and organ size control in vertebrate epimorphic regeneration is not fully understood. To examine the requirement of Hippo pathway transcriptional regulators in epimorphic regeneration, including organ size control, we inhibited these regulators during Xenopus tadpole tail regeneration by overexpressing a dominant-negative form of Yap (dnYap) or Tead4 (dnTead4) under a heat-shock promoter in transgenic animal lines. Each inhibition resulted in regeneration defects accompanied by reduced cell mitosis and increased apoptosis. Single-cell gene manipulation experiments indicated that Tead4 cell-autonomously regulates the survival of neural progenitor cells in the regenerating tail. In amphibians, amputation at the proximal level of the tail (deep amputation) results in faster regeneration than that at the distal level (shallow amputation), to restore the original-sized tail with similar timing. However, dnTead4 overexpression abolished the position-dependent differential growth rate of tail regeneration. These results suggest that the transcriptional regulators in the Hippo pathway, Tead4 and Yap1, are required for general vertebrate

  11. Frizzled3 Controls Axonal Polarity and Intermediate Target Entry during Striatal Pathway Development.

    PubMed

    Morello, Francesca; Prasad, Asheeta A; Rehberg, Kati; Vieira de Sá, Renata; Antón-Bolaños, Noelia; Leyva-Diaz, Eduardo; Adolfs, Youri; Tissir, Fadel; López-Bendito, Guillermina; Pasterkamp, R Jeroen

    2015-10-21

    The striatum is a large brain nucleus with an important role in the control of movement and emotions. Medium spiny neurons (MSNs) are striatal output neurons forming prominent descending axon tracts that target different brain nuclei. However, how MSN axon tracts in the forebrain develop remains poorly understood. Here, we implicate the Wnt binding receptor Frizzled3 in several uncharacterized aspects of MSN pathway formation [i.e., anterior-posterior guidance of MSN axons in the striatum and their subsequent growth into the globus pallidus (GP), an important (intermediate) target]. In Frizzled3 knock-out mice, MSN axons fail to extend along the anterior-posterior axis of the striatum, and many do not reach the GP. Wnt5a acts as an attractant for MSN axons in vitro, is expressed in a posterior high, anterior low gradient in the striatum, and Wnt5a knock-out mice phenocopy striatal anterior-posterior defects observed in Frizzled3 mutants. This suggests that Wnt5a controls anterior-posterior guidance of MSN axons through Frizzled3. Axons that reach the GP in Frizzled3 knock-out mice fail to enter this structure. Surprisingly, entry of MSN axons into the GP non-cell-autonomously requires Frizzled3, and our data suggest that GP entry may be contingent on the correct positioning of "corridor" guidepost cells for thalamocortical axons by Frizzled3. Together, these data dissect MSN pathway development and reveal (non)cell-autonomous roles for Frizzled3 in MSN axon guidance. Further, they are the first to identify a gene that provides anterior-posterior axon guidance in a large brain nucleus and link Frizzled3 to corridor cell development. Striatal axon pathways mediate complex physiological functions and are an important therapeutic target, underscoring the need to define how these connections are established. Remarkably, the molecular programs regulating striatal pathway development remain poorly characterized. Here, we determine the embryonic ontogeny of the two main

  12. I1 Imidazoline Receptor: Novel Potential Cytoprotective Target of TVP1022, the S-Enantiomer of Rasagiline

    PubMed Central

    Frolov, Luba; Ovcharenko, Elena; Angel, Itzchak; Youdim, Moussa B. H.; Binah, Ofer

    2012-01-01

    TVP1022, the S-enantiomer of rasagiline (Azilect®) (N-propargyl-1R-aminoindan), exerts cyto/cardio-protective effects in a variety of experimental cardiac and neuronal models. Previous studies have demonstrated that the protective activity of TVP1022 and other propargyl derivatives involve the activation of p42/44 mitogen-activated protein kinase (MAPK) signaling pathway. In the current study, we further investigated the molecular mechanism of action and signaling pathways of TVP1022 which may account for the cyto/cardio-protective efficacy of the drug. Using specific receptor binding and enzyme assays, we demonstrated that the imidazoline 1 and 2 binding sites (I1 & I2) are potential targets for TVP1022 (IC50 = 9.5E-08 M and IC50 = 1.4E-07 M, respectively). Western blotting analysis showed that TVP1022 (1–20 µM) dose-dependently increased the immunoreactivity of phosphorylated p42 and p44 MAPK in rat pheochromocytoma PC12 cells and in neonatal rat ventricular myocytes (NRVM). This effect of TVP1022 was significantly attenuated by efaroxan, a selective I1 imidazoline receptor antagonist. In addition, the cytoprotective effect of TVP1022 demonstrated in NRVM against serum deprivation-induced toxicity was markedly inhibited by efaroxan, thus suggesting the importance of I1imidazoline receptor in mediating the cardioprotective activity of the drug. Our findings suggest that the I1imidazoline receptor represents a novel site of action for the cyto/cardio-protective efficacy of TVP1022. PMID:23166584

  13. Pathways from maternal effortful control to child self-regulation: The role of maternal emotional support.

    PubMed

    Zeytinoglu, Selin; Calkins, Susan D; Swingler, Margaret M; Leerkes, Esther M

    2017-03-01

    This study examined the direct and indirect pathways from maternal effortful control to 2 aspects of children's self-regulation-executive functioning and behavioral regulation-via maternal emotional support. Two hundred seventy-eight children and their primary caregivers (96% mothers) participated in laboratory visits when children were 4 and 5 years, and teachers reported on children's behavior at kindergarten. At the 4-year assessment, maternal effortful control was measured using the Adult Temperament Questionnaire (Evans & Rothbart, 2007) and maternal emotional support was observed during a semistructured mother-child problem-solving task. At the 5-year assessment, children's executive functioning was measured using laboratory tasks designed to assess updating/working memory, inhibitory control, and cognitive flexibility, whereas behavioral regulation was assessed via teacher-report questionnaires on children's attention control, discipline and persistence, and work habits. Results from structural equation modeling indicated that, after controlling for child gender and minority status, and maternal education, maternal effortful control was indirectly associated with both child executive functioning and behavioral regulation through maternal emotional support. Maternal effortful control had a direct association with children's teacher-reported behavioral regulation but not observed executive functioning. These findings suggest that maternal effortful control may be a key contributing factor to the development of children's self-regulatory competencies through its impact on maternal emotional support. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  14. Design of pathway-level bioprocess monitoring and control strategies supported by metabolic networks.

    PubMed

    Isidro, Inês A; Ferreira, Ana R; Clemente, João J; Cunha, António E; Dias, João M L; Oliveira, Rui

    2013-01-01

    In this chapter we explore the basic tools for the design of bioprocess monitoring, optimization, and control algorithms that incorporate a priori knowledge of metabolic networks. The main advantage is that this ultimately enables the targeting of intracellular control variables such as metabolic reactions or metabolic pathways directly linked with productivity and product quality. We analyze in particular design methods that target elementary modes of metabolic networks. The topics covered include the analysis of the structure of metabolic networks, computation and reduction of elementary modes, measurement methods for the envirome, envirome-guided metabolic reconstruction, and macroscopic dynamic modeling and control. These topics are illustrated with applications to a cultivation process of a recombinant Pichia pastoris X33 strain expressing a single-chain antibody fragment (scFv).

  15. The exocyst subunit Sec3 is regulated by a protein quality control pathway.

    PubMed

    Kampmeyer, Caroline; Karakostova, Antonina; Schenstrøm, Signe M; Abildgaard, Amanda B; Lauridsen, Anne-Marie; Jourdain, Isabelle; Hartmann-Petersen, Rasmus

    2017-09-15

    Exocytosis involves fusion of secretory vesicles with the plasma membrane, thereby delivering membrane proteins to the cell surface and releasing material into the extracellular space. The tethering of the secretory vesicles before membrane fusion is mediated by the exocyst, an essential phylogenetically conserved octameric protein complex. Exocyst biogenesis is regulated by several processes, but the mechanisms by which the exocyst is degraded are unknown. Here, to unravel the components of the exocyst degradation pathway, we screened for extragenic suppressors of a temperature-sensitive fission yeast strain mutated in the exocyst subunit Sec3 (sec3-913). One of the suppressing DNAs encoded a truncated dominant-negative variant of the 26S proteasome subunit, Rpt2, indicating that exocyst degradation is controlled by the ubiquitin-proteasome system. The temperature-dependent growth defect of the sec3-913 strain was gene dosage-dependent and suppressed by blocking the proteasome, Hsp70-type molecular chaperones, the Pib1 E3 ubiquitin-protein ligase, and the deubiquitylating enzyme Ubp3. Moreover, defects in cell septation, exocytosis, and endocytosis in sec3 mutant strains were similarly alleviated by mutation of components in this pathway. We also found that, particularly under stress conditions, wild-type Sec3 degradation is regulated by Pib1 and the 26S proteasome. In conclusion, our results suggest that a cytosolic protein quality control pathway monitors folding and proteasome-dependent turnover of an exocyst subunit and, thereby, controls exocytosis in fission yeast. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  16. Design, implementation, and quality control in the Pathways American-Indian multicenter trial

    PubMed Central

    Stone, Elaine J.; Norman, James E.; Davis, Sally M.; Stewart, Dawn; Clay, Theresa E.; Caballero, Ben; Lohman, Timothy G.; Murray, David M.

    2016-01-01

    Background Pathways was the first multicenter American-Indian school-based study to test the effectiveness of an obesity prevention program promoting healthy eating and physical activity. Methods Pathways employed a nested cohort design in which 41 schools were randomized to intervention or control conditions and students within these schools were followed as a cohort (1,704 third graders at baseline). The study’s primary endpoint was percent body fat. Secondary endpoints were levels of fat in school lunches; time spent in physical activity; and knowledge, attitudes, and behaviors regarding diet and exercise. Quality control (QC) included design of data management systems which provided standardization and quality assurance of data collection and processing. Data QC procedures at study centers included manuals of operation, training and certification, and monitoring of performance. Process evaluation was conducted to monitor dose and fidelity of the interventions. Registration and tracking systems were used for students and schools. Results No difference in mean percent body fat at fifth grade was found between the intervention and control schools. Percent of calories from fat and saturated fat in school lunches was significantly reduced in the intervention schools as was total energy intake from 24-hour recalls. Significant increases in self-reported physical activity levels and knowledge of healthy behaviors were found for the intervention school students. Conclusions The Pathways study results provide evidence demonstrating the role schools can play in public health promotion. Its study design and QC systems and procedures provide useful models for other similar school based multi- or single-site studies. PMID:14636805

  17. Brain acetylcholinesterase activity controls systemic cytokine levels through the cholinergic anti-inflammatory pathway

    PubMed Central

    Pavlov, Valentin A.; Parrish, William R.; Rosas-Ballina, Mauricio; Ochani, Mahendar; Puerta, Margot; Ochani, Kanta; Chavan, Sangeeta; Al-Abed, Yousef; Tracey, Kevin J.

    2015-01-01

    The excessive release of cytokines by the immune system contributes importantly to the pathogenesis of inflammatory diseases. Recent advances in understanding the biology of cytokine toxicity led to the discovery of the “cholinergic anti-inflammatory pathway,” defined as neural signals transmitted via the vagus nerve that inhibit cytokine release through a mechanism that requires the alpha7 subunit-containing nicotinic acetylcholine receptor (α7nAChR). Vagus nerve regulation of peripheral functions is controlled by brain nuclei and neural networks, but despite considerable importance, little is known about the molecular basis for central regulation of the vagus nerve-based cholinergic anti-inflammatory pathway. Here we report that brain acetylcholinesterase activity controls systemic and organ specific TNF production during endotoxemia. Peripheral administration of the acetylcholinesterase inhibitor galantamine significantly reduced serum TNF levels through vagus nerve signaling, and protected against lethality during murine endotoxemia. Administration of a centrally-acting muscarinic receptor antagonist abolished the suppression of TNF by galantamine, indicating that suppressing acetylcholinesterase activity, coupled with central muscarinic receptors, controls peripheral cytokine responses. Administration of galantamine to α7nAChR knockout mice failed to suppress TNF levels, indicating that the α7nAChR-mediated cholinergic anti-inflammatory pathway is required for the anti-inflammatory effect of galantamine. These findings show that inhibition of brain acetylcholinesterase suppresses systemic inflammation through a central muscarinic receptor-mediated and vagal- and α7nAChR-dependent mechanism. Our data also indicate that a clinically used centrally-acting acetylcholinesterase inhibitor can be utilized to suppress abnormal inflammation to therapeutic advantage. PMID:18639629

  18. The pathways of mitophagy for quality control and clearance of mitochondria.

    PubMed

    Ashrafi, G; Schwarz, T L

    2013-01-01

    Selective autophagy of mitochondria, known as mitophagy, is an important mitochondrial quality control mechanism that eliminates damaged mitochondria. Mitophagy also mediates removal of mitochondria from developing erythrocytes, and contributes to maternal inheritance of mitochondrial DNA through the elimination of sperm-derived mitochondria. Recent studies have identified specific regulators of mitophagy that ensure selective sequestration of mitochondria as cargo. In yeast, the mitochondrial outer membrane protein autophagy-related gene 32 (ATG32) recruits the autophagic machinery to mitochondria, while mammalian Nix is required for degradation of erythrocyte mitochondria. The elimination of damaged mitochondria in mammals is mediated by a pathway comprised of PTEN-induced putative protein kinase 1 (PINK1) and the E3 ubiquitin ligase Parkin. PINK1 and Parkin accumulate on damaged mitochondria, promote their segregation from the mitochondrial network, and target these organelles for autophagic degradation in a process that requires Parkin-dependent ubiquitination of mitochondrial proteins. Here we will review recent advances in our understanding of the different pathways of mitophagy. In addition, we will discuss the relevance of these pathways in neurons where defects in mitophagy have been implicated in neurodegeneration.

  19. Conserved Genetic Pathways Controlling the Development of the Diffuse Endocrine System in Vertebrates and Drosophila

    PubMed Central

    Hartenstein, Volker; Takashima, Shigeo; Adams, Katrina

    2014-01-01

    The midgut epithelium is formed by absorptive enterocytes, secretory cells and endocrine cells. Each of these lineages is derived from the pluripotent progenitors that constitute the embryonic endoderm; the mature midgut retains pools of self-renewing stem cells that continue to produce all lineages. Recent findings in vertebrates and Drosophila shed light on the genetic mechanism that specifies the fate of the different lineages. A pivotal role is played by the Notch signaling pathway that, in a manner that appears to be very similar to the way in which Notch signaling selects neural progenitors within the neurectoderm, distinguishes the fate of secretory/endocrine cells and enterocytes. Proneural genes encoding bHLH transcription factors are expressed and required in prospective endocrine cells; activation of the Notch pathways restricts the number of these cells and promotes enterocyte development. In this review we compare the development of the intestinal endocrine cells in vertebrates and insects and summarize recent findings dealing with genetic pathways controlling this cell type. PMID:20005229

  20. Integrated protein quality-control pathways regulate free α-globin in murine β-thalassemia

    PubMed Central

    Khandros, Eugene; Thom, Christopher S.; D'Souza, Janine

    2012-01-01

    Cells remove unstable polypeptides through protein quality-control (PQC) pathways such as ubiquitin-mediated proteolysis and autophagy. In the present study, we investigated how these pathways are used in β-thalassemia, a common hemoglobinopathy in which β-globin gene mutations cause the accumulation and precipitation of cytotoxic α-globin subunits. In β-thalassemic erythrocyte precursors, free α-globin was polyubiquitinated and degraded by the proteasome. These cells exhibited enhanced proteasome activity, and transcriptional profiling revealed coordinated induction of most proteasome subunits that was mediated by the stress-response transcription factor Nrf1. In isolated thalassemic cells, short-term proteasome inhibition blocked the degradation of free α-globin. In contrast, prolonged in vivo treatment of β-thalassemic mice with the proteasome inhibitor bortezomib did not enhance the accumulation of free α-globin. Rather, systemic proteasome inhibition activated compensatory proteotoxic stress-response mechanisms, including autophagy, which cooperated with ubiquitin-mediated proteolysis to degrade free α-globin in erythroid cells. Our findings show that multiple interregulated PQC responses degrade excess α-globin. Therefore, β-thalassemia fits into the broader framework of protein-aggregation disorders that use PQC pathways as cell-protective mechanisms. PMID:22427201

  1. Conserved genetic pathways controlling the development of the diffuse endocrine system in vertebrates and Drosophila.

    PubMed

    Hartenstein, Volker; Takashima, Shigeo; Adams, Katrina L

    2010-05-01

    The midgut epithelium is formed by absorptive enterocytes, secretory cells and endocrine cells. Each of these lineages is derived from the pluripotent progenitors that constitute the embryonic endoderm; the mature midgut retains pools of self-renewing stem cells that continue to produce all lineages. Recent findings in vertebrates and Drosophila shed light on the genetic mechanism that specifies the fate of the different lineages. A pivotal role is played by the Notch signaling pathway that, in a manner that appears to be very similar to the way in which Notch signaling selects neural progenitors within the neurectoderm, distinguishes the fate of secretory/endocrine cells and enterocytes. Proneural genes encoding bHLH transcription factors are expressed and required in prospective endocrine cells; activation of the Notch pathways restricts the number of these cells and promotes enterocyte development. In this review we compare the development of the intestinal endocrine cells in vertebrates and insects and summarize recent findings dealing with genetic pathways controlling this cell type. Copyright 2009. Published by Elsevier Inc.

  2. Control of cell number by Drosophila FOXO: downstream and feedback regulation of the insulin receptor pathway

    PubMed Central

    Puig, Oscar; Marr, Michael T.; Ruhf, M. Laure; Tjian, Robert

    2003-01-01

    The Drosophila insulin receptor (dInR) regulates cell growth and proliferation through the dPI3K/dAkt pathway, which is conserved in metazoan organisms. Here we report the identification and functional characterization of the Drosophila forkhead-related transcription factor dFOXO, a key component of the insulin signaling cascade. dFOXO is phosphorylated by dAkt upon insulin treatment, leading to cytoplasmic retention and inhibition of its transcriptional activity. Mutant dFOXO lacking dAkt phosphorylation sites no longer responds to insulin inhibition, remains in the nucleus, and is constitutively active. dFOXO activation in S2 cells induces growth arrest and activates two key players of the dInR/dPI3K/dAkt pathway: the translational regulator d4EBP and the dInR itself. Induction of d4EBP likely leads to growth inhibition by dFOXO, whereas activation of dInR provides a novel transcriptionally induced feedback control mechanism. Targeted expression of dFOXO in fly tissues regulates organ size by specifying cell number with no effect on cell size. Our results establish dFOXO as a key transcriptional regulator of the insulin pathway that modulates growth and proliferation. PMID:12893776

  3. The Fanconi anemia protein FANCM is controlled by FANCD2 and the ATR/ATM pathways.

    PubMed

    Sobeck, Alexandra; Stone, Stacie; Landais, Igor; de Graaf, Bendert; Hoatlin, Maureen E

    2009-09-18

    Genomic stability requires a functional Fanconi anemia (FA) pathway composed of an upstream "core complex" (FA proteins A/B/C/E/F/G/L/M) that mediates monoubiquitination of the downstream targets FANCD2 and FANCI. Unique among FA core complex members, FANCM has processing activities toward replication-associated DNA structures, suggesting a vital role for FANCM during replication. Using Xenopus egg extracts, we analyzed the functions of FANCM in replication and the DNA damage response. xFANCM binds chromatin in a replication-dependent manner and is phosphorylated in response to DNA damage structures. Chromatin binding and DNA damage-induced phosphorylation of xFANCM are mediated in part by the downstream FA pathway protein FANCD2. Moreover, phosphorylation and chromatin recruitment of FANCM is regulated by two mayor players in the DNA damage response: the cell cycle checkpoint kinases ATR and ATM. Our results indicate that functions of FANCM are controlled by FA- and non-FA pathways in the DNA damage response.

  4. The ribosome quality control pathway can access nascent polypeptides stalled at the Sec61 translocon.

    PubMed

    von der Malsburg, Karina; Shao, Sichen; Hegde, Ramanujan S

    2015-06-15

    Cytosolic ribosomes that stall during translation are split into subunits, and nascent polypeptides trapped in the 60S subunit are ubiquitinated by the ribosome quality control (RQC) pathway. Whether the RQC pathway can also target stalls during cotranslational translocation into the ER is not known. Here we report that listerin and NEMF, core RQC components, are bound to translocon-engaged 60S subunits on native ER membranes. RQC recruitment to the ER in cultured cells is stimulated by translation stalling. Biochemical analyses demonstrated that translocon-targeted nascent polypeptides that subsequently stall are polyubiquitinated in 60S complexes. Ubiquitination at the translocon requires cytosolic exposure of the polypeptide at the ribosome-Sec61 junction. This exposure can result from either failed insertion into the Sec61 channel or partial backsliding of translocating nascent chains. Only Sec61-engaged nascent chains early in their biogenesis were relatively refractory to ubiquitination. Modeling based on recent 60S-RQC and 80S-Sec61 structures suggests that the E3 ligase listerin accesses nascent polypeptides via a gap in the ribosome-translocon junction near the Sec61 lateral gate. Thus the RQC pathway can target stalled translocation intermediates for degradation from the Sec61 channel.

  5. The ribosome quality control pathway can access nascent polypeptides stalled at the Sec61 translocon

    PubMed Central

    von der Malsburg, Karina; Shao, Sichen; Hegde, Ramanujan S.

    2015-01-01

    Cytosolic ribosomes that stall during translation are split into subunits, and nascent polypeptides trapped in the 60S subunit are ubiquitinated by the ribosome quality control (RQC) pathway. Whether the RQC pathway can also target stalls during cotranslational translocation into the ER is not known. Here we report that listerin and NEMF, core RQC components, are bound to translocon-engaged 60S subunits on native ER membranes. RQC recruitment to the ER in cultured cells is stimulated by translation stalling. Biochemical analyses demonstrated that translocon-targeted nascent polypeptides that subsequently stall are polyubiquitinated in 60S complexes. Ubiquitination at the translocon requires cytosolic exposure of the polypeptide at the ribosome–Sec61 junction. This exposure can result from either failed insertion into the Sec61 channel or partial backsliding of translocating nascent chains. Only Sec61-engaged nascent chains early in their biogenesis were relatively refractory to ubiquitination. Modeling based on recent 60S–RQC and 80S–Sec61 structures suggests that the E3 ligase listerin accesses nascent polypeptides via a gap in the ribosome–translocon junction near the Sec61 lateral gate. Thus the RQC pathway can target stalled translocation intermediates for degradation from the Sec61 channel. PMID:25877867

  6. Advanced Instrumentation, Information, and Control Systems Technologies Pathway: FY 2016 External Review

    SciTech Connect

    Thomas, Kenneth David; Hallbert, Bruce Perry

    2016-11-01

    This report describes an External Review conducted by the LWRS Program Advanced Instrumentation, Information, and Control (II&C) Systems Technologies Pathway to solicit feedback on the topics and results of the ongoing II&C research program. This review was held in conjunction with the Nuclear Energy Institute (NEI) Digital I&C Working Group meeting that was held at Idaho National Laboratory (INL) on August 9-10, 2016. Given the opportunity to visit INL and see the pathway research projects, NEI agreed that the Working Group would serve as the External Review panel for the purpose of obtaining expert input on the value and timing of the research projects. This consisted of demonstrations in the Human Systems Simulation Laboratory followed by presentations on the II&C research program in general as well as the five technology development areas. Following the meeting, the presentations were sent to each of the attendees so they could review them in more detail and refer to them in completing the feedback form. Follow-up activities were conducted with the attendees following the meeting to obtain the completed feedback forms. A total of 13 forms were returned. The feedback forms were reviewed by the pathway to compile the data and comments received, which are documented in the report. In all, the feedback provided by the External Review participants is taken to be a strong endorsement of the types of projects being conducted by the pathway, the value they hold for the nuclear plants, and the general timing of need. The feedback aligns well with the priorities, levels of efforts allocated for the research projects, and project schedules. The feedback also represents realistic observations on the practicality of some aspects of implementing these technologies. In some cases, the participants provided thoughtful challenges to certain assumptions in the formulation of the technologies or in deployment plans. These deserve further review and revision of plans if warranted

  7. Integrative neuro-endocrine pathways in the control of reproduction in lamprey: a brief review.

    PubMed

    Freamat, Mihael; Sower, Stacia A

    2013-10-18

    The gonadotropin-releasing hormone (GnRH) system is well known as the main regulator of reproductive physiology in vertebrates. It is also part of a network of brain structures and pathways that integrate information from the internal and external milieu and coordinate the adaptive behavioral and physiological responses to social and reproductive survival needs. In this paper we review the state of knowledge of the GnRH system in relation to the behavior, external, and internal factors that control reproduction in one of the oldest lineage of vertebrates, the lampreys.

  8. Integrative Neuro-Endocrine Pathways in the Control of Reproduction in Lamprey: A Brief Review

    PubMed Central

    Freamat, Mihael; Sower, Stacia A.

    2013-01-01

    The gonadotropin-releasing hormone (GnRH) system is well known as the main regulator of reproductive physiology in vertebrates. It is also part of a network of brain structures and pathways that integrate information from the internal and external milieu and coordinate the adaptive behavioral and physiological responses to social and reproductive survival needs. In this paper we review the state of knowledge of the GnRH system in relation to the behavior, external, and internal factors that control reproduction in one of the oldest lineage of vertebrates, the lampreys. PMID:24151489

  9. Tim-3 pathway controls regulatory and effector T cell balance during hepatitis C virus infection.

    PubMed

    Moorman, Jonathan P; Wang, Jia M; Zhang, Ying; Ji, Xiao J; Ma, Cheng J; Wu, Xiao Y; Jia, Zhan S; Wang, Ke S; Yao, Zhi Q

    2012-07-15

    Hepatitis C virus (HCV) is remarkable at disrupting human immunity to establish chronic infection. Upregulation of inhibitory signaling pathways (such as T cell Ig and mucin domain protein-3 [Tim-3]) and accumulation of regulatory T cells (Tregs) play pivotal roles in suppressing antiviral effector T cell (Teff) responses that are essential for viral clearance. Although the Tim-3 pathway has been shown to negatively regulate Teffs, its role in regulating Foxp3(+) Tregs is poorly explored. In this study, we investigated whether and how the Tim-3 pathway alters Foxp3(+) Treg development and function in patients with chronic HCV infection. We found that Tim-3 was upregulated, not only on IL-2-producing CD4(+)CD25(+)Foxp3(-) Teffs, but also on CD4(+)CD25(+)Foxp3(+) Tregs, which accumulate in the peripheral blood of chronically HCV-infected individuals when compared with healthy subjects. Tim-3 expression on Foxp3(+) Tregs positively correlated with expression of the proliferation marker Ki67 on Tregs, but it was inversely associated with proliferation of IL-2-producing Teffs. Moreover, Foxp3(+) Tregs were found to be more resistant to, and Foxp3(-) Teffs more sensitive to, TCR activation-induced cell apoptosis, which was reversible by blocking Tim-3 signaling. Consistent with its role in T cell proliferation and apoptosis, blockade of Tim-3 on CD4(+)CD25(+) T cells promoted expansion of Teffs more substantially than Tregs through improving STAT-5 signaling, thus correcting the imbalance of Foxp3(+) Tregs/Foxp3(-) Teffs that was induced by HCV infection. Taken together, the Tim-3 pathway appears to control Treg and Teff balance through altering cell proliferation and apoptosis during HCV infection.

  10. Cytoprotective regulation of the mitochondrial permeability transition pore is impaired in type 2 diabetic Goto-Kakizaki rat hearts.

    PubMed

    Itoh, Takahito; Kouzu, Hidemichi; Miki, Takayuki; Tanno, Masaya; Kuno, Atsushi; Sato, Tatsuya; Sunaga, Daisuke; Murase, Hiromichi; Miura, Tetsuji

    2012-12-01

    Our recent studies indicated that up-regulation of calcineurin activity and unfolded protein responses (UPRs) disrupt cytoprotective Akt- and ERK-signaling in OLETF, a model of obese type 2 diabetes (T2DM). To determine whether the mechanisms can be generalized, we used Goto-Kakizaki rats (GK), a model of non-obese T2DM, in this study. Infarct sizes after 20-min ischemia/2-h reperfusion were similar in GK and non-diabetic controls, Wistar rats (Wistar). However, erythropoietin (EPO) limited infarct size in Wistar (64.0±5.3% vs. 45.7±4.4%, p<0.05) but not in GK (56.2±2.2% vs. 52.6±2.3%). Levels of calcineurin activity and EPO-induced phosphorylation of Akt and ERK were similar in GK and Wistar, though cytosolic HSP70 level was 50% lower and mitochondrial HSP60 level was 60% higher in GK. EPO preserved mitochondrial calcium retention capacity (CRC), an index of the threshold for opening of the mitochondrial permeability transition pore (mPTP), after ischemia/reperfusion in Wistar but not in GK. Interaction of cyclophilin D (CypD) with mitochondrial inorganic phosphate carrier (PiC), which sensitizes the mPTP, was enhanced in GK. There was a negative exponential relationship between CypD-PiC interaction and CRC upon reperfusion, indicating that increase in CRC by reduction of CypD-PiC interaction is smaller when CypD-PiC interaction level is at a higher range. A chemical chaperone, 4-phenylbutyric acid, attenuated the changes in HSPs and CypD-PiC interaction and restored responses of CRC and infarct size to EPO in GK. These results suggest that cytoprotective regulation of the mPTP is impaired in GK by enhanced CypD-PiC interaction in which UPRs are involved. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. [Cytoprotection of gastric mucosa induced by tripotassium-dicitrato bismuthate against ethanol stress. Dependent mechanisms of sulfhydryl, dopaminergic and endogenous prostaglandin].

    PubMed

    Laudanno, O M; Bodini, O A; San Miguel, P; Cesolari, J A; Capdopon, E

    1986-01-01

    In groups of white Wistar rats, the cytoprotective effect induced by TDB on the gastric mucosa against the ethanol injury, was studied; where macroscopic protection and histologic cytoprotection in gastric corpus was found, and no in antrum mucosa. The cytoprotective mechanism give by TDB, were studied by the test of Indomethacin, Cl2Hg, Domperidone, Chlorpromazine and Acetazolamide, where each drug was given as pretreatment. Was conclude that TDB give gastric cytoprotection by the mechanism of the nonprotein sulfhydryl, by to be one peripheral agonist of the neuronal dopamine receptors, by increase of endogenous prostaglandin, by little increment of cAMP and no participate the gastric bicarbonate secretion.

  12. The prefrontal cortex achieves inhibitory control by facilitating subcortical motor pathway connectivity.

    PubMed

    Rae, Charlotte L; Hughes, Laura E; Anderson, Michael C; Rowe, James B

    2015-01-14

    Communication between the prefrontal cortex and subcortical nuclei underpins the control and inhibition of behavior. However, the interactions in such pathways remain controversial. Using a stop-signal response inhibition task and functional imaging with analysis of effective connectivity, we show that the lateral prefrontal cortex influences the strength of communication between regions in the frontostriatal motor system. We compared 20 generative models that represented alternative interactions between the inferior frontal gyrus, presupplementary motor area (preSMA), subthalamic nucleus (STN), and primary motor cortex during response inhibition. Bayesian model selection revealed that during successful response inhibition, the inferior frontal gyrus modulates an excitatory influence of the preSMA on the STN, thereby amplifying the downstream polysynaptic inhibition from the STN to the motor cortex. Critically, the strength of the interaction between preSMA and STN, and the degree of modulation by the inferior frontal gyrus, predicted individual differences in participants' stopping performance (stop-signal reaction time). We then used diffusion-weighted imaging with tractography to assess white matter structure in the pathways connecting these three regions. The mean diffusivity in tracts between preSMA and the STN, and between the inferior frontal gyrus and STN, also predicted individual differences in stopping efficiency. Finally, we found that white matter structure in the tract between preSMA and STN correlated with effective connectivity of the same pathway, providing important cross-modal validation of the effective connectivity measures. Together, the results demonstrate the network dynamics and modulatory role of the prefrontal cortex that underpin individual differences in inhibitory control.

  13. The Prefrontal Cortex Achieves Inhibitory Control by Facilitating Subcortical Motor Pathway Connectivity

    PubMed Central

    Hughes, Laura E.; Anderson, Michael C.; Rowe, James B.

    2015-01-01

    Communication between the prefrontal cortex and subcortical nuclei underpins the control and inhibition of behavior. However, the interactions in such pathways remain controversial. Using a stop-signal response inhibition task and functional imaging with analysis of effective connectivity, we show that the lateral prefrontal cortex influences the strength of communication between regions in the frontostriatal motor system. We compared 20 generative models that represented alternative interactions between the inferior frontal gyrus, presupplementary motor area (preSMA), subthalamic nucleus (STN), and primary motor cortex during response inhibition. Bayesian model selection revealed that during successful response inhibition, the inferior frontal gyrus modulates an excitatory influence of the preSMA on the STN, thereby amplifying the downstream polysynaptic inhibition from the STN to the motor cortex. Critically, the strength of the interaction between preSMA and STN, and the degree of modulation by the inferior frontal gyrus, predicted individual differences in participants' stopping performance (stop-signal reaction time). We then used diffusion-weighted imaging with tractography to assess white matter structure in the pathways connecting these three regions. The mean diffusivity in tracts between preSMA and the STN, and between the inferior frontal gyrus and STN, also predicted individual differences in stopping efficiency. Finally, we found that white matter structure in the tract between preSMA and STN correlated with effective connectivity of the same pathway, providing important cross-modal validation of the effective connectivity measures. Together, the results demonstrate the network dynamics and modulatory role of the prefrontal cortex that underpin individual differences in inhibitory control. PMID:25589771

  14. A novel Drosophila Girdin-like protein is involved in Akt pathway control of cell size

    SciTech Connect

    Puseenam, Aekkachai; Yoshioka, Yasuhide; Nagai, Rika; Hashimoto, Reina; Suyari, Osamu; Itoh, Masanobu; Enomoto, Atsushi; Takahashi, Masahide; Yamaguchi, Masamitsu

    2009-11-15

    The Akt signaling pathway is well known to regulate cell proliferation and growth. Girdin, a novel substrate of Akt, plays a crucial role in organization of the actin cytoskeleton and cell motility under the control of Akt. We here identified a novel Girdin-like protein in Drosophila (dGirdin), which has two isoforms, dGirdin PA and dGirdin PB. dGirdin shows high homology with human Girdin in the N-terminal and coiled-coil domains, while diverging at the C-terminal domain. On establishment of transgenic fly lines, featuring knockdown or overexpression of dGirdin in vivo, overexpression in the wing disc cells induced ectopic apoptosis, implying a role in directing apoptosis. Knockdown of dGirdin in the Drosophila wing imaginal disc cells resulted in reduction of cell size. Furthermore, this was enhanced by half reduction of the Akt gene dose, suggesting that Akt positively regulates dGirdin. In the wing disc, cells in which dGirdin was knocked down exhibited disruption of actin filaments. From these in vivo analyses, we conclude that dGirdin is required for actin organization and regulation of appropriate cell size under control of the Akt signaling pathway.

  15. Bile acid homeostasis controls CAR signaling pathways in mouse testis through FXRalpha

    PubMed Central

    Martinot, Emmanuelle; Baptissart, Marine; Véga, Aurélie; Sèdes, Lauriane; Rouaisnel, Betty; Vaz, Fred; Saru, Jean-Paul; de Haze, Angélique; Baron, Silvère; Caira, Françoise; Beaudoin, Claude; Volle, David H.

    2017-01-01

    Bile acids (BAs) are molecules with endocrine activities controlling several physiological functions such as immunity, glucose homeostasis, testicular physiology and male fertility. The role of the nuclear BA receptor FXRα in the control of BA homeostasis has been well characterized. The present study shows that testis synthetize BAs. We demonstrate that mice invalidated for the gene encoding FXRα have altered BA homeostasis in both liver and testis. In the absence of FXRα, BA exposure differently alters hepatic and testicular expression of genes involved in BA synthesis. Interestingly, Fxrα-/- males fed a diet supplemented with BAs show alterations of testicular physiology and sperm production. This phenotype was correlated with the altered testicular BA homeostasis and the production of intermediate metabolites of BAs which led to the modulation of CAR signaling pathways within the testis. The role of the CAR signaling pathways within testis was validated using specific CAR agonist (TCPOBOP) and inverse agonist (androstanol) that respectively inhibited or reproduced the phenotype observed in Fxrα-/- males fed BA-diet. These data open interesting perspectives to better define how BA homeostasis contributes to physiological or pathophysiological conditions via the modulation of CAR activity. PMID:28181583

  16. Plant cysteine oxidases control the oxygen-dependent branch of the N-end-rule pathway

    PubMed Central

    Weits, Daan A.; Giuntoli, Beatrice; Kosmacz, Monika; Parlanti, Sandro; Hubberten, Hans-Michael; Riegler, Heike; Hoefgen, Rainer; Perata, Pierdomenico; van Dongen, Joost T.; Licausi, Francesco

    2014-01-01

    In plant and animal cells, amino-terminal cysteine oxidation controls selective proteolysis via an oxygen-dependent branch of the N-end rule pathway. It remains unknown how the N-terminal cysteine is specifically oxidized. Here we identify plant cysteine oxidase (PCO) enzymes that oxidize the penultimate cysteine of ERF-VII transcription factors by using oxygen as a co-substrate, thereby controlling the lifetime of these proteins. Consequently, ERF-VII proteins are stabilized under hypoxia and activate the molecular response to low oxygen while the expression of anaerobic genes is repressed in air. Members of the PCO family are themselves targets of ERF-VII transcription factors, generating a feedback loop that adapts the stress response according to the extent of the hypoxic condition. Our results reveal that PCOs act as sensor proteins for oxygen in plants and provide an example of how proactive regulation of the N-end rule pathway balances stress response to optimal growth and development in plants. PMID:24599061

  17. Inositol phosphate pathway controls transcription of telomeric expression sites in trypanosomes.

    PubMed

    Cestari, Igor; Stuart, Ken

    2015-05-26

    African trypanosomes evade clearance by host antibodies by periodically changing their variant surface glycoprotein (VSG) coat. They transcribe only one VSG gene at a time from 1 of about 20 telomeric expression sites (ESs). They undergo antigenic variation by switching transcription between telomeric ESs or by recombination of the VSG gene expressed. We show that the inositol phosphate (IP) pathway controls transcription of telomeric ESs and VSG antigenic switching in Trypanosoma brucei. Conditional knockdown of phosphatidylinositol 5-kinase (TbPIP5K) or phosphatidylinositol 5-phosphatase (TbPIP5Pase) or overexpression of phospholipase C (TbPLC) derepresses numerous silent ESs in T. brucei bloodstream forms. The derepression is specific to telomeric ESs, and it coincides with an increase in the number of colocalizing telomeric and RNA polymerase I foci in the nucleus. Monoallelic VSG transcription resumes after reexpression of TbPIP5K; however, most of the resultant cells switched the VSG gene expressed. TbPIP5K, TbPLC, their substrates, and products localize to the plasma membrane, whereas TbPIP5Pase localizes to the nucleus proximal to telomeres. TbPIP5Pase associates with repressor/activator protein 1 (TbRAP1), and their telomeric silencing function is altered by TbPIP5K knockdown. These results show that specific steps in the IP pathway control ES transcription and antigenic switching in T. brucei by epigenetic regulation of telomere silencing.

  18. Bile acid homeostasis controls CAR signaling pathways in mouse testis through FXRalpha.

    PubMed

    Martinot, Emmanuelle; Baptissart, Marine; Véga, Aurélie; Sèdes, Lauriane; Rouaisnel, Betty; Vaz, Fred; Saru, Jean-Paul; de Haze, Angélique; Baron, Silvère; Caira, Françoise; Beaudoin, Claude; Volle, David H

    2017-02-09

    Bile acids (BAs) are molecules with endocrine activities controlling several physiological functions such as immunity, glucose homeostasis, testicular physiology and male fertility. The role of the nuclear BA receptor FXRα in the control of BA homeostasis has been well characterized. The present study shows that testis synthetize BAs. We demonstrate that mice invalidated for the gene encoding FXRα have altered BA homeostasis in both liver and testis. In the absence of FXRα, BA exposure differently alters hepatic and testicular expression of genes involved in BA synthesis. Interestingly, Fxrα-/- males fed a diet supplemented with BAs show alterations of testicular physiology and sperm production. This phenotype was correlated with the altered testicular BA homeostasis and the production of intermediate metabolites of BAs which led to the modulation of CAR signaling pathways within the testis. The role of the CAR signaling pathways within testis was validated using specific CAR agonist (TCPOBOP) and inverse agonist (androstanol) that respectively inhibited or reproduced the phenotype observed in Fxrα-/- males fed BA-diet. These data open interesting perspectives to better define how BA homeostasis contributes to physiological or pathophysiological conditions via the modulation of CAR activity.

  19. Control of Neuropeptide Expression by Parallel Activity-dependent Pathways in Caenorhabditis elegans

    PubMed Central

    Rojo Romanos, Teresa; Petersen, Jakob Gramstrup; Pocock, Roger

    2017-01-01

    Monitoring of neuronal activity within circuits facilitates integrated responses and rapid changes in behavior. We have identified a system in Caenorhabditis elegans where neuropeptide expression is dependent on the ability of the BAG neurons to sense carbon dioxide. In C. elegans, CO2 sensing is predominantly coordinated by the BAG-expressed receptor-type guanylate cyclase GCY-9. GCY-9 binding to CO2 causes accumulation of cyclic GMP and opening of the cGMP-gated TAX-2/TAX-4 cation channels; provoking an integrated downstream cascade that enables C. elegans to avoid high CO2. Here we show that cGMP regulation by GCY-9 and the PDE-1 phosphodiesterase controls BAG expression of a FMRFamide-related neuropeptide FLP-19 reporter (flp-19::GFP). This regulation is specific for CO2-sensing function of the BAG neurons, as loss of oxygen sensing function does not affect flp-19::GFP expression. We also found that expression of flp-19::GFP is controlled in parallel to GCY-9 by the activity-dependent transcription factor CREB (CRH-1) and the cAMP-dependent protein kinase (KIN-2) signaling pathway. We therefore show that two parallel pathways regulate neuropeptide gene expression in the BAG sensory neurons: the ability to sense changes in carbon dioxide and CREB transcription factor. Such regulation may be required in particular environmental conditions to enable sophisticated behavioral decisions to be performed. PMID:28139692

  20. Inositol phosphate pathway controls transcription of telomeric expression sites in trypanosomes

    PubMed Central

    Cestari, Igor; Stuart, Ken

    2015-01-01

    African trypanosomes evade clearance by host antibodies by periodically changing their variant surface glycoprotein (VSG) coat. They transcribe only one VSG gene at a time from 1 of about 20 telomeric expression sites (ESs). They undergo antigenic variation by switching transcription between telomeric ESs or by recombination of the VSG gene expressed. We show that the inositol phosphate (IP) pathway controls transcription of telomeric ESs and VSG antigenic switching in Trypanosoma brucei. Conditional knockdown of phosphatidylinositol 5-kinase (TbPIP5K) or phosphatidylinositol 5-phosphatase (TbPIP5Pase) or overexpression of phospholipase C (TbPLC) derepresses numerous silent ESs in T. brucei bloodstream forms. The derepression is specific to telomeric ESs, and it coincides with an increase in the number of colocalizing telomeric and RNA polymerase I foci in the nucleus. Monoallelic VSG transcription resumes after reexpression of TbPIP5K; however, most of the resultant cells switched the VSG gene expressed. TbPIP5K, TbPLC, their substrates, and products localize to the plasma membrane, whereas TbPIP5Pase localizes to the nucleus proximal to telomeres. TbPIP5Pase associates with repressor/activator protein 1 (TbRAP1), and their telomeric silencing function is altered by TbPIP5K knockdown. These results show that specific steps in the IP pathway control ES transcription and antigenic switching in T. brucei by epigenetic regulation of telomere silencing. PMID:25964327

  1. Quality Control Pathways for Nucleus-Encoded Eukaryotic tRNA Biosynthesis and Subcellular Trafficking

    PubMed Central

    Huang, Hsiao-Yun

    2015-01-01

    tRNAs perform an essential role in translating the genetic code. They are long-lived RNAs that are generated via numerous posttranscriptional steps. Eukaryotic cells have evolved numerous layers of quality control mechanisms to ensure that the tRNAs are appropriately structured, processed, and modified. We describe the known tRNA quality control processes that check tRNAs and correct or destroy aberrant tRNAs. These mechanisms employ two types of exonucleases, CCA end addition, tRNA nuclear aminoacylation, and tRNA subcellular traffic. We arrange these processes in order of the steps that occur from generation of precursor tRNAs by RNA polymerase (Pol) III transcription to end maturation and modification in the nucleus to splicing and additional modifications in the cytoplasm. Finally, we discuss the tRNA retrograde pathway, which allows tRNA reimport into the nucleus for degradation or repair. PMID:25848089

  2. From Stimulation to Undulation: A Neuronal Pathway for the Control of Swimming in the Leech

    NASA Astrophysics Data System (ADS)

    Brodfuehrer, Peter D.; Friesen, W. Otto

    1986-11-01

    Initiation and performance of the swimming movement in the leech (Hirudo medicinalis) are controlled by neurons organized at at least four functional levels--sensory neurons, gating neurons, oscillator neurons, and motor neurons. A paired neuron, designated as Tr1, in the subesophageal ganglion of the leech has now been shown to define a fifth level, interposed between sensory and gating neurons. Cell Tr1 is activated by pressure and nociceptive mechanosensory neurons, which mediate body-wall stimulus--evoked swimming activity in intact leeches. In the isolated leech nervous system, brief stimulation of cell Tr1 elicits sustained activation of the gating neurons and triggers the onset of swimming activity. The synaptic interactions between all five levels of control are direct. Discovery of the Tr1 cells thus completes the identification of a synaptic pathway by which mechanosensory stimulation leads to the swimming movements of the leech.

  3. Complexity of contrasting flow controls on phosphorus flux and transfer pathways

    NASA Astrophysics Data System (ADS)

    Mellander, Per-Erik; Jordan, Phil; Shore, Mairead; Melland, Alice R.; Shortle, Ger

    2015-04-01

    Insights on hydrological processes from 'rain to stream' are important when interpreting the effectiveness of measures for reducing phosphorus (P) losses from agricultural sources to water bodies. A general understanding is that measures for management of P transfers along surface pathways will be consistently effective when applied on a whole territory approach. It is, however, necessary for policies to incorporate an understanding of spatial and temporal variation in hydrological flow controls, associated nutrient transfer pathways and chemical processes along the pathways. This variation is associated with variability in soil drainage, geology, climate and land management between hillslopes and catchments. In this study, four years of hourly stream P flux data from two Irish agricultural catchments were analysed on an annual and event flow basis. The analysis was related to hydrological flow paths in order to help develop a catchment scale (ca. 10 km2) theory of P export and associated processes that could help with specific P mitigation policies in heterogeneous river basin planning zones. A grassland catchment with mostly poorly drained soils and a 'flashy hydrology' had three times higher annual P flux than an arable catchment with mostly well-drained soils and a more buffered hydrology (1.04 kg total P ha-1 compared to 0.34 kg total P ha-1), despite the arable catchment having larger areas with high soil P status and more discharge. Neither of the catchments indicated P supply limitations. The magnitude of the P fluxes from the two catchments were not defined by land use, source pressure or discharge volume, but rather by a more basic rainfall-to-runoff partitioning which influenced the proportions of quickflow and slowflow. Despite the catchments having contrasting flow controls and P transfer pathways, there were larger differences in P loss between the years than between the catchments and the P loss from the arable catchment appeared to be more sensitive

  4. The primary cilium coordinates signaling pathways in cell cycle control and migration during development and tissue repair.

    PubMed

    Christensen, Søren T; Pedersen, Stine F; Satir, Peter; Veland, Iben R; Schneider, Linda

    2008-01-01

    Cell cycle control and migration are critical processes during development and maintenance of tissue functions. Recently, primary cilia were shown to take part in coordination of the signaling pathways that control these cellular processes in human health and disease. In this review, we present an overview of the function of primary cilia and the centrosome in the signaling pathways that regulate cell cycle control and migration with focus on ciliary signaling via platelet-derived growth factor receptor alpha (PDGFRalpha). We also consider how the primary cilium and the centrosome interact with the extracellular matrix, coordinate Wnt signaling, and modulate cytoskeletal changes that impinge on both cell cycle control and cell migration.

  5. Cytoprotective Effects of Hydrophilic and Lipophilic Extracts of Pistacia vera against Oxidative Versus Carbonyl Stress in Rat Hepatocytes

    PubMed Central

    Shahraki, Jafar; Zareh, Mona; Kamalinejad, Mohammad; Pourahmad, Jalal

    2014-01-01

    This study was conducted to evaluate the cytoprotection of various extracts and bioactive compounds found in Pistacia vera againts cytotoxicity, ROS formation, lipid peroxidation, protein carbonylation, mitochondrial and lysosomal membrane damages in cell toxicity models of diabetes related carbonyl (glyoxal) and oxidative stress (hydroperoxide). Methanol, water and ethyl acetate were used to prepare crude pistachios extracts, which were then used to screen for in-vitro cytoprotection of freshly isolated rat hepatocytes against these toxins. The order of protection by Pistacia vera extracts against both hydroperoxide induced oxidative stress (ROS formation) and glyoxal induced protein carbonylation was: pistachio methanolic extract >pistachio water extract, gallic acid, catechin> α-tochoferol and pistachio ethyl acetate extract. Finally due to higher protection achieved by methanolic extract even compared to sole pretreatment of gallic acid, catechin or α-tochoferol, we suggest that cytoprotection depends on the variety of polar and non-polar compounds found in methanolic extract, it is likely that multiple cytoprotective mechanisms are acting against oxidative and carbonyl induced cytotoxicity. To our knowledge, we are the first to report the cytoprotective activity of Pistacia vera extracts against oxidative and carbonyl stress seen in type 2 diabetes hepatocytes model. PMID:25587316

  6. Comparative cytoprotection of cultured corneal endothelial cells by water-soluble antioxidants against free-radical damage.

    PubMed

    Zeng, L H; Rootman, D S; Fung, K P; Wu, T W

    1995-09-01

    We reported previously that purpurogallin (PPG) markedly protects the cultured rabbit corneal endothelial cells (RCEC) against oxyradical damage generated with hypoxanthine (HX) and xanthine oxidase (XO)(1). In this study, we further compared the cytoprotective activities of PPG versus Trolox (TX, alpha-tocopherol, a water-soluble analogue of vitamin E) and ascorbate (Asc) in confluent cultured RCEC with phase contrast microscopy and confirmed by transmission electron microscopy. PPG prolonged survival of the oxyradical damaged cells longer than those without PPG present (18.6 +/- 1.4 min at 1.0 mM and 11.2 +/- 1.0 at 0.25 mM respectively vs. 7.3 +/- 0.8 min in control). At levels equimolar to PPG, TX, and Asc were less effective in delaying cell necrosis caused by HX and XO (p < 0.01). When exposed to superoxide radicals generated by menadione, RCEC necrosed at 29.8 +/- 1.5 min compared to PPG 47.2 +/- 1.0 min at 1.0 mM and 38.9 +/- 1.0 min at 0.25 mM. This was significantly different from TX and Asc at corresponding concentrations (p < 0.01). PPG scavenges not only HX-XO-generated oxyradicals, but also nonenzymatically produced superoxide radicals, more actively than two well known antioxidants--TX and Asc.

  7. Gastric anti-ulcer and cytoprotective effect of selenium in rats

    SciTech Connect

    Parmar, N.S.; Tariq, M.; Ageel, A.M.

    1988-01-01

    Selenium, a trace element, in the form of sodium selenite has been studied for its ability to protect the gastric mucosa against the injuries caused by hypothermic restraint stress, aspirin, indomethacin, reserpine, dimaprit, and various other gastric mucosal-damaging (necrotizing) agents in rats. The results demonstrate that oral administration of sodium selenite produces a significant inhibition of the gastric mucosal damage induced by all the procedures used in this study. Selenium, in a nonantisecretory dose, produced a marked cytoprotective effect against all the necrotizing agents. The cytoprotective effect of selenium against the effects of 80% ethanol and 0.6 M HCl was significantly reversed by prior treatment with a dose of indomethacin that inhibits prostaglandin biosynthesis. These data indicate that sodium selenite inhibits the formation of these lesions by the mucosal generation of prostaglandins. The concentrations of nonprotein sulfhydryls (NP-SH) were significantly decreased in the gastric mucosa following the administration of necrotizing agents--80% ethanol and 0.6 M HCl. Treatment with sodium selenite, which significantly reduced the intensity of gastric lesions, did not replenish the reduced levels of gastric mucosal NP-SH, thus ruling out the mediation of its protective effect through sulfhydryls. The antisecretory effect of sodium selenite, which becomes evident only in the high dose of 20 mumol/kg, may be responsible for the inhibition of gastric lesions induced by aspirin, indomethacin, reserpine, and dimaprit. Our findings show that selenium possesses significant anti-ulcer and adaptive cytoprotective effects. However, further detailed studies are required to confirm these effects, to establish its mechanism(s) of action, and to determine its role in the prophylaxis and treatment of peptic ulcer disease.

  8. Frequency Modulated Translocational Oscillations of Nrf2 Mediate the Antioxidant Response Element Cytoprotective Transcriptional Response

    PubMed Central

    Xue, Mingzhan; Momiji, Hiroshi; Rabbani, Naila; Barker, Guy; Bretschneider, Till; Shmygol, Anatoly; Rand, David A.

    2015-01-01

    Abstract Aims: Stress responsive signaling coordinated by nuclear factor erythroid 2-related factor 2 (Nrf2) provides an adaptive response for protection of cells against toxic insults, oxidative stress and metabolic dysfunction. Nrf2 regulates a battery of protective genes by binding to regulatory antioxidant response elements (AREs). The aim of this study was to examine how Nrf2 signals cell stress status and regulates transcription to maintain homeostasis. Results: In live cell microscopy we observed that Nrf2 undergoes autonomous translocational frequency-modulated oscillations between cytoplasm and nucleus. Oscillations occurred in quiescence and when cells were stimulated at physiological levels of activators, they decrease in period and amplitude and then evoke a cytoprotective transcriptional response. We propose a mechanism whereby oscillations are produced by negative feedback involving successive de-phosphorylation and phosphorylation steps. Nrf2 was inactivated in the nucleus and reactivated on return to the cytoplasm. Increased frequency of Nrf2 on return to the cytoplasm with increased reactivation or refresh-rate under stress conditions activated the transcriptional response mediating cytoprotective effects. The serine/threonine-protein phosphatase PGAM5, member of the Nrf2 interactome, was a key regulatory component. Innovation: We found that Nrf2 is activated in cells without change in total cellular Nrf2 protein concentration. Regulation of ARE-linked protective gene transcription occurs rather through translocational oscillations of Nrf2. We discovered cytoplasmic refresh rate of Nrf2 is important in maintaining and regulating the transcriptional response and links stress challenge to increased cytoplasmic surveillance. We found silencing and inhibition of PGAM5 provides potent activation of Nrf2. Conclusion: Frequency modulated translocational oscillations of Nrf2 mediate the ARE-linked cytoprotective transcriptional response. Antioxid. Redox

  9. Studies on the cytoprotective and antisecretory activity of ebrotidine. A review.

    PubMed

    Konturek, P C; Brzozowski, T; Konturek, S I; Márquez, M; Torres, J; Ortiz, J A

    1997-04-01

    Gastric mucosa is exposed to various aggressive factors such as stress, ulcerogenic drugs including acetyl-salicylic acid(ASA)-like agents, ethanol, bacteria, particularly Helicobacter pylori (Hp), and various endogenous irritants such as acid-pepsin secretion and bile salts. The maintenance of the mucosal barrier depends upon the activation of the pre-epithelial (mucus-alkali secretion), epithelial (surface-active phospholipids and rapid mucosal restitution) and post-epithelial (mucosal microcirculation, sensory nerves and mast cells) components of mucosal defense. Ebrotidine (N-[(E)-[[2-[[[2-[(diaminomethylene)amino]- 4-thiazolyl]methyl]thio]ethyl]amino]methylene]-4-bromo-benzenesulfonamid e, CAS 100981-43-9, FI-3542) is the first of a new generation of H2-receptor antagonists with both antisecretory and cytoprotective activities. Its inhibitory action is similar to that of ranitidine and approximately tenfold greater than cimetidine, and is accompanied by a small and transient increase in plasma gastrin levels. In contrast to ranitidine and other H2-receptor antagonists, ebrotidine exerts a unique cytoprotection against injury by various ulcerogens such as ethanol, ammonia, lipopolysaccharides (LPS), stress and ASA or acidified taurocholate. The mechanism of this protection by ebrotidine is not clear, but it has been shown to stimulate mucus secretion, to increase the quality of adherent mucus gel and to increase gastric mucosal blood flow (GBF), possibly due to enhanced mucosal formation of prostaglandin E2 (PGE2) and nitric oxide (NO). The cytoprotective effects of ebrotidine were observed in rats and confirmed also in humans with gastric lesions induced by ethanol or ASA. Ebrotidine also exerts anti-Helicobacter pylori (Hp) effects by interfering with surface receptors of epithelial cells and inhibiting urease, protease and lipase activity, and by counteracting the noxious effects of Hp-related substances such as ammonia and lipopoly-saccharides (LPS).

  10. Cytoprotective role of taurine in a renal epithelial cell culture model.

    PubMed

    Eppler, Bärbel; Dawson, Ralph

    2002-03-15

    Taurine (TAU) is a sulfur-containing amino acid that has been shown to decrease during aging and is believed to be important for cytoprotection. A decrease in TAU could exacerbate the accumulation of free radical-induced damage that may lead to cell death during the aging process. We have shown previously that TAU directly inhibits dopamine (DA) and (-)-3-(3,4-dihydroxyphenyl)-L-alanine (L-dopa) oxidation. Experiments were conducted to establish a cytoprotective role for TAU. Porcine renal epithelial cells were treated for 1 hr with iron and catecholamines (L-dopa and DA) to produce cytotoxicity by a free radical and quinone mechanism in the absence and presence of 10 or 20mM TAU. Viability assays, protein, and DNA measurements were performed after a 24hr recovery period. In some experiments, cells were extracted immediately after the insult for DA and TAU content measurements using high performance liquid chromatography with electrochemical detection. Catecholamine-induced cytotoxicity caused a 50% loss in cell viability, and 10 or 20mM TAU provided significant protection from cytotoxicity and maintained the functional integrity of the cells. Photomicrographs showed attenuation in cell loss and swelling in the presence of TAU. Pretreatment with 1mM TAU followed by exposure to iron and L-dopa in the presence of 1mM TAU caused a moderate but non-significant increase in cell survival. These data conclusively show that TAU can play a cytoprotective role in the LLC-PK(1) cell culture model.

  11. Involvement of protein kinase C in the delayed cytoprotection following sublethal ischaemia in rabbit myocardium.

    PubMed Central

    Baxter, G. F.; Goma, F. M.; Yellon, D. M.

    1995-01-01

    Rabbit hearts were preconditioned with four 5 min coronary artery occlusions 24 h before 30 min coronary occlusion with 120 min reperfusion. Preconditioning significantly reduced the percentage of myocardium infarcting within the risk zone from 49.1 +/- 4.3% to 31.8 +/- 3.5% (P < 0.05). When the protein kinase C (PKC) inhibitor, chelerythrine, was administered just before preconditioning, the delayed protection against infarction 24 h later was abolished. We conclude that the delayed cytoprotective response associated with ischaemic preconditioning of myocardium is likely to involve the early activation of one or more PKC subtypes. PMID:7545515

  12. [Tanakan as a multimodal cytoprotective factor in general medicine (part II)].

    PubMed

    Esin, R G; Naprienko, M V; Mukhametova, E R; Khairullin, I Kh; Esin, O R

    2015-01-01

    The second section of the review provides an update of the data on mechanisms of action of a standardized extract of Ginkgo biloba EGb761® (tanakan) and its efficacy in treatment of depression, pain, complications of diabetes, Parkinson disease, tinnitus and dizziness, reproductive dysfunction. Updated data enable to use EGb761® (tanakan) as a highly-effective cytoprotective agent in treatment of cardiovascular, degenerative and metabolic diseases of the nervous system, inner ear disturbances (tinnitus), dysfunction of reproductive system as well as in prevention and treatment of stress-induced disorders.

  13. Mitochondrial superoxide radicals mediate programmed cell death in Trypanosoma cruzi: cytoprotective action of mitochondrial iron superoxide dismutase overexpression

    PubMed Central

    Piacenza, Lucía; Irigoín, Florencia; Alvarez, María Noel; Peluffo, Gonzalo; Taylor, Martin C.; Kelly, John M.; Wilkinson, Shane R.; Radi, Rafael

    2006-01-01

    Trypanosoma cruzi undergo PCD (programmed cell death) under appropriate stimuli, the mechanisms of which remain to be established. In the present study, we show that stimulation of PCD in T. cruzi epimastigotes by FHS (fresh human serum) results in rapid (<1 h) externalization of phosphatidylserine and depletion of the low molecular mass thiols dihydrotrypanothione and glutathione. Concomitantly, enhanced generation of oxidants was established by EPR and immuno-spin trapping of radicals using DMPO (5,5-dimethylpyrroline-N-oxide) and augmentation of the glucose flux through the pentose phosphate pathway. In the early period (<20 min), changes in mitochondrial membrane potential and inhibition of respiration, probably due to the impairment of ADP/ATP exchange with the cytosol, were observed, conditions that favour the generation of O2•−. Accelerated rates of mitochondrial O2•− production were detected by the inactivation of the redox-sensitive mitochondrial aconitase and by oxidation of a mitochondrial-targeted probe (MitoSOX). Importantly, parasites overexpressing mitochondrial FeSOD (iron superoxide dismutase) were more resistant to the PCD stimulus, unambiguously indicating the participation of mitochondrial O2•− in the signalling process. In summary, FHS-induced PCD in T. cruzi involves mitochondrial dysfunction that causes enhanced O2•− formation, which leads to cellular oxidative stress conditions that trigger the initiation of PCD cascades; moreover, overexpression of mitochondrial FeSOD, which is also observed during metacyclogenesis, resulted in cytoprotective effects. PMID:17168856

  14. The GTPase regulatory proteins Pix and Git control tissue growth via the Hippo pathway.

    PubMed

    Dent, Lucas G; Poon, Carole L C; Zhang, Xiaomeng; Degoutin, Joffrey L; Tipping, Marla; Veraksa, Alexey; Harvey, Kieran F

    2015-01-05

    The Salvador-Warts-Hippo (Hippo) pathway is a conserved regulator of organ size and is deregulated in human cancers. In epithelial tissues, the Hippo pathway is regulated by fundamental cell biological properties, such as polarity and adhesion, and coordinates these with tissue growth. Despite its importance in disease, development, and regeneration, the complete set of proteins that regulate Hippo signaling remain undefined. To address this, we used proteomics to identify proteins that bind to the Hippo (Hpo) kinase. Prominent among these were PAK-interacting exchange factor (known as Pix or RtGEF) and G-protein-coupled receptor kinase-interacting protein (Git). Pix is a conserved Rho-type guanine nucleotide exchange factor (Rho-GEF) homologous to Beta-PIX and Alpha-PIX in mammals. Git is the single Drosophila melanogaster homolog of the mammalian GIT1 and GIT2 proteins, which were originally identified in the search for molecules that interact with G-protein-coupled receptor kinases. Pix and Git form an oligomeric scaffold to facilitate sterile 20-like kinase activation and have also been linked to GTPase regulation. We show that Pix and Git regulate Hippo-pathway-dependent tissue growth in D. melanogaster and that they do this in parallel to the known upstream regulator Fat cadherin. Pix and Git influence activity of the Hpo kinase by acting as a scaffold complex, rather than enzymes, and promote Hpo dimerization and autophosphorylation of Hpo's activation loop. Therefore, we provide important new insights into an ancient signaling network that controls the growth of metazoan tissues. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. 10-Oxo-trans-11-octadecenoic acid generated from linoleic acid by a gut lactic acid bacterium Lactobacillus plantarum is cytoprotective against oxidative stress.

    PubMed

    Furumoto, Hidehiro; Nanthirudjanar, Tharnath; Kume, Toshiaki; Izumi, Yasuhiko; Park, Si-Bum; Kitamura, Nahoko; Kishino, Shigenobu; Ogawa, Jun; Hirata, Takashi; Sugawara, Tatsuya

    2016-04-01

    Oxidative stress is a well-known cause of multiple diseases. The nuclear factor erythroid 2-related factor 2 (Nrf2)-antioxidant response element (ARE) pathway plays a central role in cellular antioxidative responses. In this study, we investigated the effects of novel fatty acid metabolite derivatives of linoleic acid generated by the gut lactic acid bacteria Lactobacillus plantarum on the Nrf2-ARE pathway. 10-Oxo-trans-11-octadecenoic acid (KetoC) protected HepG2 cells from cytotoxicity induced by hydrogen peroxide. KetoC also significantly increased cellular Nrf2 protein levels, ARE-dependent transcription, and the gene expression of antioxidative enzymes such as heme oxygenase-1 (HO-1), glutamate-cysteine ligase modifier subunit (GCLM), and quinone oxidoreductase 1 (NQO1) in HepG2 cells. Additionally, a single oral dose administration of KetoC also increased antioxidative gene expression and protein levels of Nrf2 and HO-1 in mouse organs. Since other fatty acid metabolites and linoleic acid did not affect cellular antioxidative responses, the cytoprotective effect of KetoC may be because of its α,β-unsaturated carbonyl moiety. Collectively, our data suggested that KetoC activated the Nrf2-ARE pathway to enhance cellular antioxidative responses in vitro and in vivo, which further suggests that KetoC may prevent multiple diseases induced by oxidative stress. Copyright © 2016. Published by Elsevier Inc.

  16. A developmentally regulated translational control pathway establishes the meiotic chromosome segregation pattern

    PubMed Central

    Berchowitz, Luke E.; Gajadhar, Aaron S.; van Werven, Folkert J.; De Rosa, Alexandra A.; Samoylova, Mariya L.; Brar, Gloria A.; Xu, Yifeng; Xiao, Che; Futcher, Bruce; Weissman, Jonathan S.; White, Forest M.; Amon, Angelika

    2013-01-01

    Production of haploid gametes from diploid progenitor cells is mediated by a specialized cell division, meiosis, where two divisions, meiosis I and II, follow a single S phase. Errors in progression from meiosis I to meiosis II lead to aneuploid and polyploid gametes, but the regulatory mechanisms controlling this transition are poorly understood. Here, we demonstrate that the conserved kinase Ime2 regulates the timing and order of the meiotic divisions by controlling translation. Ime2 coordinates translational activation of a cluster of genes at the meiosis I–meiosis II transition, including the critical determinant of the meiotic chromosome segregation pattern CLB3. We further show that Ime2 mediates translational control through the meiosis-specific RNA-binding protein Rim4. Rim4 inhibits translation of CLB3 during meiosis I by interacting with the 5′ untranslated region (UTR) of CLB3. At the onset of meiosis II, Ime2 kinase activity rises and triggers a decrease in Rim4 protein levels, thereby alleviating translational repression. Our results elucidate a novel developmentally regulated translational control pathway that establishes the meiotic chromosome segregation pattern. PMID:24115771

  17. Neural pathways mediating control of reproductive behaviour in male Japanese quail

    PubMed Central

    Wild, J Martin; Balthazart, Jacques

    2012-01-01

    The sexually dimorphic medial preoptic nucleus (POM) in Japanese quail has for many years been the focus of intensive investigations into its role in reproductive behaviour. The present paper delineates a sequence of descending pathways that finally reach sacral levels of the spinal cord housing motor neurons innervating cloacal muscles involved in reproductive behaviour. We first retrogradely labeled the motor neurons innervating the large cloacal sphincter muscle (mSC) that forms part of the foam gland complex (Seiwert and Adkins-Regan, 1998, Brain Behav Evol 52:61–80) and then putative premotor nuclei in the brainstem, one of which was nucleus retroambigualis (RAm) in the caudal medulla. Anterograde tracing from RAm defined a bulbospinal pathway, terminations of which overlapped the distribution of mSC motor neurons and their extensive dorsally directed dendrites. Descending input to RAm arose from an extensive dorsomedial nucleus of the intercollicular complex (DM-ICo), electrical stimulation of which drove vocalizations. POM neurons were retrogradely labeled by injections of tracer into DM-ICo, but POM projections largely surrounded DM, rather than penetrated it. Thus, although a POM projection to ICo was shown, a POM projection to DM must be inferred. Nevertheless, the sequence of projections in the male quail from POM to cloacal motor neurons strongly resembles that in rats, cats and monkeys for the control of reproductive behaviour, as largely defined by Holstege and co-workers (e.g., Holstege et al., 1997, Neuroscience 80: 587–598). PMID:23225613

  18. A Receptor-associated Protein/Phosphatidylinositol 3-Kinase Pathway Controls Pseudopod Formation

    PubMed Central

    Kortholt, Arjan; Bolourani, Parvin; Rehmann, Holger; Keizer-Gunnink, Ineke; Weeks, Gerald; Wittinghofer, Alfred

    2010-01-01

    GbpD, a Dictyostelium discoideum guanine exchange factor specific for Rap1, has been implicated in adhesion, cell polarity, and chemotaxis. Cells overexpressing GbpD are flat, exhibit strongly increased cell-substrate attachment, and extend many bifurcated and lateral pseudopodia. Phg2, a serine/threonine-specific kinase, mediates Rap1-regulated cell-substrate adhesion, but not cell polarity or chemotaxis. In this study we demonstrate that overexpression of GbpD in pi3k1/2-null cells does not induce the adhesion and cell morphology phenotype. Furthermore we show that Rap1 directly binds to the Ras binding domain of PI3K, and overexpression of GbpD leads to strongly enhanced PIP3 levels. Consistently, upon overexpression of the PIP3-degradating enzyme PTEN in GbpD-overexpressing cells, the strong adhesion and cell morphology phenotype is largely lost. These results indicate that a GbpD/Rap/PI3K pathway helps control pseudopod formation and cell polarity. As in Rap-regulated pseudopod formation in Dictyostelium, mammalian Rap and PI3K are essential for determining neuronal polarity, suggesting that the Rap/PI3K pathway is a conserved module regulating the establishment of cell polarity. PMID:20089846

  19. Thioredoxin m4 Controls Photosynthetic Alternative Electron Pathways in Arabidopsis1[C][W

    PubMed Central

    Courteille, Agathe; Vesa, Simona; Sanz-Barrio, Ruth; Cazalé, Anne-Claire; Becuwe-Linka, Noëlle; Farran, Immaculada; Havaux, Michel; Rey, Pascal; Rumeau, Dominique

    2013-01-01

    In addition to the linear electron flow, a cyclic electron flow (CEF) around photosystem I occurs in chloroplasts. In CEF, electrons flow back from the donor site of photosystem I to the plastoquinone pool via two main routes: one that involves the Proton Gradient Regulation5 (PGR5)/PGRL1 complex (PGR) and one that is dependent of the NADH dehydrogenase-like complex. While the importance of CEF in photosynthesis and photoprotection has been clearly established, little is known about its regulation. We worked on the assumption of a redox regulation and surveyed the putative role of chloroplastic thioredoxins (TRX). Using Arabidopsis (Arabidopsis thaliana) mutants lacking different TRX isoforms, we demonstrated in vivo that TRXm4 specifically plays a role in the down-regulation of the NADH dehydrogenase-like complex-dependent plastoquinone reduction pathway. This result was confirmed in tobacco (Nicotiana tabacum) plants overexpressing the TRXm4 orthologous gene. In vitro assays performed with isolated chloroplasts and purified TRXm4 indicated that TRXm4 negatively controls the PGR pathway as well. The physiological significance of this regulation was investigated under steady-state photosynthesis and in the pgr5 mutant background. Lack of TRXm4 reversed the growth phenotype of the pgr5 mutant, but it did not compensate for the impaired photosynthesis and photoinhibition sensitivity. This suggests that the physiological role of TRXm4 occurs in vivo via a mechanism distinct from direct up-regulation of CEF. PMID:23151348

  20. Evidence for a conserved CCAP-signaling pathway controlling ecdysis in a hemimetabolous insect, Rhodnius prolixus

    PubMed Central

    Lee, DoHee; Orchard, Ian; Lange, Angela B.

    2013-01-01

    A vital feature in the success of Ecdysozoa is their ability to shed their exoskeleton (a process called ecdysis) such that they can grow or change their morphology. In holometabolous insects, these behaviors are orchestrated by the sequential actions of neuropeptides, one of which is crustacean cardioactive peptide (CCAP). Little is known about the control of ecdysis in hemimetabolous insects. Here, we report that CCAP is essential for successful ecdysis in the hemimetabolous insect, Rhodnius prolixus; the vector of Chagas disease. The first indication of CCAP's involvement in ecdysis was the observation of decreased staining intensity of CCAP-containing neurons immediately following ecdysis, indicative of the release of CCAP. The critical importance of the CCAP signaling pathway was further demonstrated by knockdown (as determined by qPCR and immunohistochemistry) of the CCAP and CCAPR transcripts utilizing dsRNA. This technique reduced the staining intensity of CCAP-containing neurons, and knocked down the transcript levels by up to 92%, with lethal consequences to the insect. Insects with these transcripts knocked down had very high mortality (up to 84%), typically at the expected time of the ecdysis sequence, or had ecdysis extremely delayed. This is the first report of the susceptibility of R. prolixus to dsRNA knockdown of neuropeptide and receptor transcripts, and the data clearly demonstrates the conserved nature of the CCAP signaling pathway in ecdysis between holometabolous and hemimetabolous insects. PMID:24204330

  1. ITIM-dependent negative signaling pathways for the control of cell-mediated xenogeneic immune responses.

    PubMed

    del Rio, Maria-Luisa; Seebach, Jörg D; Fernández-Renedo, Carlos; Rodriguez-Barbosa, Jose-Ignacio

    2013-01-01

    Xenotransplantation is an innovative field of research with the potential to provide us with an alternative source of organs to face the severe shortage of human organ donors. For several reasons, pigs have been chosen as the most suitable source of organs and tissues for transplantation in humans. However, porcine xenografts undergo cellular immune responses representing a major barrier to their acceptance and normal functioning. Innate and adaptive xenogeneic immunity is mediated by both the recognition of xenogeneic tissue antigens and the lack of inhibition due to molecular cross-species incompatibilities of regulatory pathways. Therefore, the delivery of immunoreceptor tyrosine-based inhibitory motif (ITIM)-dependent and related negative signals to control innate (NK cells, macrophages) and adaptive T and B cells might overcome cell-mediated xenogeneic immunity. The proof of this concept has already been achieved in vitro by the transgenic overexpression of human ligands of several inhibitory receptors in porcine cells resulting in their resistance against xenoreactivity. Consequently, several transgenic pigs expressing tissue-specific human ligands of inhibitory coreceptors (HLA-E, CD47) or soluble competitors of costimulation (belatacept) have already been generated. The development of these robust and innovative approaches to modulate human anti-pig cellular immune responses, complementary to conventional immunosuppression, will help to achieve long-term xenograft survival. In this review, we will focus on the current strategies to enhance negative signaling pathways for the regulation of undesirable cell-mediated xenoreactive immune responses.

  2. Dynamic control over supramolecular handedness by selecting chiral induction pathways at the solution-solid interface.

    PubMed

    Fang, Yuan; Ghijsens, Elke; Ivasenko, Oleksandr; Cao, Hai; Noguchi, Aya; Mali, Kunal S; Tahara, Kazukuni; Tobe, Yoshito; De Feyter, Steven

    2016-07-01

    A dominant theme within the research on two-dimensional chirality is the sergeant-soldiers principle, wherein a small fraction of chiral molecules (sergeants) is used to skew the handedness of achiral molecules (soldiers) to generate a homochiral surface. Here, we have combined the sergeant-soldiers principle with temperature-dependent molecular self-assembly to unravel a peculiar chiral amplification mechanism at the solution-solid interface in which, depending on the concentration of a sergeant-soldiers solution, the majority handedness of the system can either be amplified or entirely reversed after an annealing step, furnishing a homochiral surface. Two discrete pathways that affect different stages of two-dimensional crystal growth are invoked for rationalizing this phenomenon and we present a set of experiments where the access to each pathway can be precisely controlled. These results demonstrate that a detailed understanding of subtle intermolecular and interfacial interactions can be used to induce drastic changes in the handedness of a supramolecular network.

  3. R-spondin1 Controls Muscle Cell Fusion through Dual Regulation of Antagonistic Wnt Signaling Pathways.

    PubMed

    Lacour, Floriane; Vezin, Elsa; Bentzinger, C Florian; Sincennes, Marie-Claude; Giordani, Lorenzo; Ferry, Arnaud; Mitchell, Robert; Patel, Ketan; Rudnicki, Michael A; Chaboissier, Marie-Christine; Chassot, Anne-Amandine; Le Grand, Fabien

    2017-03-07

    Wnt-mediated signals are involved in many important steps in mammalian regeneration. In multiple cell types, the R-spondin (Rspo) family of secreted proteins potently activates the canonical Wnt/β-catenin pathway. Here, we identify Rspo1 as a mediator of skeletal muscle tissue repair. First, we show that deletion of Rspo1 results in global alteration of muscle regeneration kinetics following acute injury. We find that muscle progenitor cells lacking Rspo1 show delayed differentiation due to reduced activation of Wnt/β-catenin target genes. Furthermore, muscle cells lacking Rspo1 have a fusion phenotype leading to larger myotubes containing supernumerary nuclei both in vitro and in vivo. The increase in muscle fusion was dependent on downregulation of Wnt/β-catenin and upregulation of non-canonical Wnt7a/Fzd7/Rac1 signaling. We conclude that reciprocal control of antagonistic Wnt signaling pathways by Rspo1 in muscle stem cell progeny is a key step ensuring normal tissue architecture restoration following acute damage.

  4. The STING controlled cytosolic-DNA activated innate immune pathway and microbial disease.

    PubMed

    Konno, Hiroyasu; Barber, Glen N

    2014-12-01

    The innate immune system is critically important for the primary sensing of invading pathogens. Over the past decade, the cellular sensors important for recognizing microbial entry into the host cell have been largely elucidated. These sensors, some of which are evolutionarily conserved, include the Toll-like receptor (TLR) and RIG-I-like helicase family (RLH) pathway that can recognize bacterial and viral non-self nucleic acid. In addition, a cellular sensor referred to as STING (for stimulator of interferon genes) has been shown to be critical for triggering host defense countermeasures, including stimulation of the adaptive immune response, following the detection of cytosolic DNA species. The STING pathway has now been shown to be critical for activating innate immune gene transcription in response to infection by DNA pathogens such as herpes simplex virus 1 (HSV1) as well as retroviruses. In addition, it is clear that chronic STING activation can also cause autoinflammatory disease manifested by self-DNA. Here we review recent developments in our understanding of STING function, including importance in the control of microbial disease.

  5. Evaluation of the nutraceutical, antioxidant and cytoprotective properties of ripe pistachio (Pistacia vera L., variety Bronte) hulls.

    PubMed

    Barreca, Davide; Laganà, Giuseppina; Leuzzi, Ugo; Smeriglio, Antonella; Trombetta, Domenico; Bellocco, Ersilia

    2016-04-01

    Every year tons of pistachio hulls are separated and eliminated, as waste products, from pistachio seeds. In this study the hulls of ripe pistachios were extracted with two organic solvents (ethanol and methanol) and characterized for phenolic composition, antioxidant power and cytoprotective activity. RP-HPLC-DAD-FLU separation enabled us to identify 20 derivatives, including and by far the most abundant gallic acid, 4-hydroxybenzoic acid, protocatechuic acid, naringin, eriodictyol-7-O-glucoside, isorhamnetin-7-O-glucoside, quercetin-3-O-rutinoside, isorhamnetin-3-O-glucoside and catechin. Methanol extraction gave the highest yields for all classes of compounds and presented a higher scavenging activity in all the antioxidant assays performed. The same was found for cytoprotective activity on lymphocytes, lipid peroxidation and protein degradation. These findings highlight the strong antioxidant and cytoprotective activity of the extract components, and illustrate how a waste product can be used as a source of nutraceuticals to employ in manufacturing industry.

  6. Cytoprotective effects of essential oil of Pinus halepensis L. against aspirin-induced toxicity in IEC-6 cells.

    PubMed

    Bouzenna, Hafsia; Hfaiedh, Najla; Bouaziz, Mouhamed; Giroux-Metges, Marie-Agnès; Elfeki, Abdelfattah; Talarmin, Hélène

    2017-07-18

    Essential oils from Pinus species have been reported to have various therapeutic properties. This study was undertaken to identify the chemical composition and cytoprotective effects of the essential oil of Pinus halepensis L. against aspirin-induced damage in cells in vitro. The cytoprotection of the oil against toxicity of aspirin on the small intestine epithelial cells IEC-6 was tested. The obtained results have shown that 35 different compounds were identified. Aspirin induced a decrease in cell viability, and exhibited significant damage to their morphology and an increase in superoxide dismutase (SOD) and catalase (CAT) activities. However, the co-treatment of aspirin with the essential oil of Pinus induced a significant increase in cell viability and a decrease in SOD and CAT activities. Overall, these finding suggest that the essential oil of Pinus halepensis L. has potent cytoprotective effect against aspirin-induced toxicity in IEC-6 cells.

  7. Drug target identification in sphingolipid metabolism by computational systems biology tools: metabolic control analysis and metabolic pathway analysis.

    PubMed

    Ozbayraktar, F Betül Kavun; Ulgen, Kutlu O

    2010-08-01

    Sphingolipids regulate cellular processes that are critically important in cell's fate and function in cancer development and progression. This fact underlies the basics of the novel cancer therapy approach. The pharmacological manipulation of the sphingolipid metabolism in cancer therapeutics necessitates the detailed understanding of the pathway. Two computational systems biology tools are used to identify potential drug target enzymes among sphingolipid pathway that can be further utilized in drug design studies for cancer therapy. The enzymes in sphingolipid pathway were ranked according to their roles in controlling the metabolic network by metabolic control analysis. The physiologically connected reactions, i.e. biologically significant and functional modules of network, were identified by metabolic pathway analysis. The final set of candidate drug target enzymes are selected such that their manipulation leads to ceramide accumulation and long chain base phosphates depletion. The mathematical tools' efficiency for drug target identification performed in this study is validated by clinically available drugs. Copyright 2010 Elsevier Inc. All rights reserved.

  8. Astroglial control of neuroinflammation: TLR3-mediated dsRNA-sensing pathways are in the focus.

    PubMed

    Salmina, Alla B; Komleva, Yulia K; Lopatina, Olga L; Kuvacheva, Natalia V; Gorina, Yana V; Panina, Yulia A; Uspenskaya, Yulia A; Petrova, Marina M; Demko, Irina V; Zamay, Anna S; Malinovskaya, Natalia A

    2015-01-01

    Neuroinflammation is as an important component of pathogenesis in many types of brain pathology. Immune mechanisms regulate neuroplasticity, memory formation, neurogenesis, behavior, brain development, cognitive functions, and brain metabolism. It is generally believed that essential homeostatic functions of astrocytes - astroglia-neuron metabolic coupling, gliovascular control, regulation of proliferation, and migration of cells in the neurogenic niches - are compromised in neuroinflammation resulting in excitotoxicity, neuronal and glial cell death, and alterations of intercellular communication. Viral neuroinfection, release of non-coding RNAs from the cells at the sites of brain injury or degeneration, and application of siRNA or RNA aptamers as therapeutic agents would require dsRNA-sensing pathways in the cells of neuronal and non-neuronal origin. In this review, we analyze the data regarding the role of astrocytes in dsRNA-initiated innate immune response in neuroinflammation and their contribution to progression of neurodegenerative and neurodevelopmental pathology.

  9. Neuronal release of d-serine: a physiological pathway controlling extracellular d-serine concentration

    PubMed Central

    Rosenberg, Dina; Kartvelishvily, Elena; Shleper, Maria; Klinker, Chanda M. C.; Bowser, Michael T.; Wolosker, Herman

    2010-01-01

    d-Serine is thought to be a glia-derived transmitter that activates N-methyl d-aspartate receptors (NMDARs) in the brain. Here, we investigate the pathways for d-serine release using primary cultures, brain slices, and in vivo microdialysis. In contrast with the notion that d-serine is exclusively released from astrocytes, we found that d-serine is released by neuronal depolarization both in vitro and in vivo. Veratridine (50 μM) or depolarization by 40 mM KCl elicits a significant release of endogenous d-serine from primary neuronal cultures. Controls with astrocyte cultures indicate that glial cells are insensitive to veratridine, but release d-serine mainly by the opening of volume-regulated anion channels. In cortical slices perfused with veratridine, endogenous d-serine release is 10-fold higher than glutamate receptor-evoked release. Release of d-serine from slices does not require internal or external Ca2+, suggesting a nonvesicular release mechanism. To confirm the neuronal origin of d-serine, we selectively loaded neurons in cortical slices with d-[3H]serine or applied d-alanine, which specifically releases d-serine from neurons. Depolarization with veratridine promotes d-serine release in vivo monitored by high temporal resolution microdialysis of the striatum. Our data indicate that the neuronal pool of d-serine plays a major role in d-serine dynamics, with implications for the regulation of NMDAR transmission. Rosenberg, D., Kartvelishvily, E., Shleper, M., Klinker, C. M. C., Bowser, M. T., Wolosker, H. Neuronal release of d-serine: a physiological pathway controlling extracellular d-serine concentration. PMID:20371631

  10. Alterations in leukocyte transcriptional control pathway activity associated with major depressive disorder and antidepressant treatment

    PubMed Central

    Mellon, S H; Wolkowitz, O M; Schonemann, M D; Epel, E S; Rosser, R; Burke, H B; Mahan, L; Reus, V I; Stamatiou, D; Liew, C -C; Cole, S W

    2016-01-01

    Major depressive disorder (MDD) is associated with a significantly elevated risk of developing serious medical illnesses such as cardiovascular disease, immune impairments, infection, dementia and premature death. Previous work has demonstrated immune dysregulation in subjects with MDD. Using genome-wide transcriptional profiling and promoter-based bioinformatic strategies, we assessed leukocyte transcription factor (TF) activity in leukocytes from 20 unmedicated MDD subjects versus 20 age-, sex- and ethnicity-matched healthy controls, before initiation of antidepressant therapy, and in 17 of the MDD subjects after 8 weeks of sertraline treatment. In leukocytes from unmedicated MDD subjects, bioinformatic analysis of transcription control pathway activity indicated an increased transcriptional activity of cAMP response element-binding/activating TF (CREB/ATF) and increased activity of TFs associated with cellular responses to oxidative stress (nuclear factor erythroid-derived 2-like 2, NFE2l2 or NRF2). Eight weeks of antidepressant therapy was associated with significant reductions in Hamilton Depression Rating Scale scores and reduced activity of NRF2, but not in CREB/ATF activity. Several other transcriptional regulation pathways, including the glucocorticoid receptor (GR), nuclear factor kappa-B cells (NF-κB), early growth response proteins 1–4 (EGR1–4) and interferon-responsive TFs, showed either no significant differences as a function of disease or treatment, or activities that were opposite to those previously hypothesized to be involved in the etiology of MDD or effective treatment. Our results suggest that CREB/ATF and NRF2 signaling may contribute to MDD by activating immune cell transcriptome dynamics that ultimately influence central nervous system (CNS) motivational and affective processes via circulating mediators. PMID:27187237

  11. Alterations in leukocyte transcriptional control pathway activity associated with major depressive disorder and antidepressant treatment.

    PubMed

    Mellon, S H; Wolkowitz, O M; Schonemann, M D; Epel, E S; Rosser, R; Burke, H B; Mahan, L; Reus, V I; Stamatiou, D; Liew, C-C; Cole, S W

    2016-05-24

    Major depressive disorder (MDD) is associated with a significantly elevated risk of developing serious medical illnesses such as cardiovascular disease, immune impairments, infection, dementia and premature death. Previous work has demonstrated immune dysregulation in subjects with MDD. Using genome-wide transcriptional profiling and promoter-based bioinformatic strategies, we assessed leukocyte transcription factor (TF) activity in leukocytes from 20 unmedicated MDD subjects versus 20 age-, sex- and ethnicity-matched healthy controls, before initiation of antidepressant therapy, and in 17 of the MDD subjects after 8 weeks of sertraline treatment. In leukocytes from unmedicated MDD subjects, bioinformatic analysis of transcription control pathway activity indicated an increased transcriptional activity of cAMP response element-binding/activating TF (CREB/ATF) and increased activity of TFs associated with cellular responses to oxidative stress (nuclear factor erythroid-derived 2-like 2, NFE2l2 or NRF2). Eight weeks of antidepressant therapy was associated with significant reductions in Hamilton Depression Rating Scale scores and reduced activity of NRF2, but not in CREB/ATF activity. Several other transcriptional regulation pathways, including the glucocorticoid receptor (GR), nuclear factor kappa-B cells (NF-κB), early growth response proteins 1-4 (EGR1-4) and interferon-responsive TFs, showed either no significant differences as a function of disease or treatment, or activities that were opposite to those previously hypothesized to be involved in the etiology of MDD or effective treatment. Our results suggest that CREB/ATF and NRF2 signaling may contribute to MDD by activating immune cell transcriptome dynamics that ultimately influence central nervous system (CNS) motivational and affective processes via circulating mediators.

  12. Case-control analysis of nucleotide excision repair pathway and the risk of renal cell carcinoma.

    PubMed

    Lin, Jie; Pu, Xia; Wang, Wei; Matin, Surena; Tannir, Nizar M; Wood, Christopher G; Wu, Xifeng

    2008-11-01

    In this population-based case-control study with 325 Caucasian renal cell carcinoma (RCC) patients and 335 controls matched to cases by age, gender and county of residence, we evaluated the associations between 13 potential functional polymorphisms in nine major nucleotide excision repair (NER) genes and RCC risk. In individual single nucleotide polymorphism analysis, after adjustment for multiple comparisons, a significantly decreased RCC risk was observed for the heterozygous genotype of XPD Asp312Asn [odds ratio (OR) = 0.62; 95% confidence interval (CI): 0.43-0.90] and for the heterozygous and homozygous variant genotypes combined in a dominant model (OR = 0.64; 95% CI: 0.46-0.89). The heterozygous AG genotype of XPA 5'untranslated region was at 1.78-fold increased risk (95% CI: 1.18-2.69) and the risk reached 2.43-fold (95% CI: 1.57-3.75) for the homozygous variant GG genotype; the risk was significant both in the dominant model and in the recessive model. In joint analysis, compared with individuals with fewer than five adverse alleles, individuals with five (OR = 1.17; 95% CI: 0.71-1.93), six (OR = 1.66; 95% CI: 1.03-2.67), seven or more (OR = 1.85; 95% CI: 1.16-2.95) exhibited a progressively increased risk of RCC (P for trend = 0.004). Further, there were significant interactions between NER pathway genes and sex, hypertension and obesity (all P for interaction <0.05). Our results strongly support that common sequence variants of the NER pathway genes predispose susceptible individuals to increased risk of RCC and that the association may be modified by gender, history of hypertension and obesity. These results need to be replicated in larger studies.

  13. Compartment-specific Control of Reactive Oxygen Species Scavenging by Antioxidant Pathway Enzymes.

    PubMed

    Dey, Swati; Sidor, Agnieszka; O'Rourke, Brian

    2016-05-20

    Oxidative stress arises from an imbalance in the production and scavenging rates of reactive oxygen species (ROS) and is a key factor in the pathophysiology of cardiovascular disease and aging. The presence of parallel pathways and multiple intracellular compartments, each having its own ROS sources and antioxidant enzymes, complicates the determination of the most important regulatory nodes of the redox network. Here we quantified ROS dynamics within specific intracellular compartments in the cytosol and mitochondria and determined which scavenging enzymes exert the most control over antioxidant fluxes in H9c2 cardiac myoblasts. We used novel targeted viral gene transfer vectors expressing redox-sensitive GFP fused to sensor domains to measure H2O2 or oxidized glutathione. Using genetic manipulation in heart-derived H9c2 cells, we explored the contribution of specific antioxidant enzymes to ROS scavenging and glutathione redox potential within each intracellular compartment. Our findings reveal that antioxidant flux is strongly dependent on mitochondrial substrate catabolism, with availability of NADPH as a major rate-controlling step. Moreover, ROS scavenging by mitochondria significantly contributes to cytoplasmic ROS handling. The findings provide fundamental information about the control of ROS scavenging by the redox network and suggest novel interventions for circumventing oxidative stress in cardiac cells.

  14. AMPKα1-LDH pathway regulates muscle stem cell self-renewal by controlling metabolic homeostasis.

    PubMed

    Theret, Marine; Gsaier, Linda; Schaffer, Bethany; Juban, Gaëtan; Ben Larbi, Sabrina; Weiss-Gayet, Michèle; Bultot, Laurent; Collodet, Caterina; Foretz, Marc; Desplanches, Dominique; Sanz, Pascual; Zang, Zizhao; Yang, Lin; Vial, Guillaume; Viollet, Benoit; Sakamoto, Kei; Brunet, Anne; Chazaud, Bénédicte; Mounier, Rémi

    2017-07-03

    Control of stem cell fate to either enter terminal differentiation versus returning to quiescence (self-renewal) is crucial for tissue repair. Here, we showed that AMP-activated protein kinase (AMPK), the master metabolic regulator of the cell, controls muscle stem cell (MuSC) self-renewal. AMPKα1(-/-) MuSCs displayed a high self-renewal rate, which impairs muscle regeneration. AMPKα1(-/-) MuSCs showed a Warburg-like switch of their metabolism to higher glycolysis. We identified lactate dehydrogenase (LDH) as a new functional target of AMPKα1. LDH, which is a non-limiting enzyme of glycolysis in differentiated cells, was tightly regulated in stem cells. In functional experiments, LDH overexpression phenocopied AMPKα1(-/-) phenotype, that is shifted MuSC metabolism toward glycolysis triggering their return to quiescence, while inhibition of LDH activity rescued AMPKα1(-/-) MuSC self-renewal. Finally, providing specific nutrients (galactose/glucose) to MuSCs directly controlled their fate through the AMPKα1/LDH pathway, emphasizing the importance of metabolism in stem cell fate. © 2017 The Authors.

  15. A Phg2-Adrm1 Pathway Participates in the Nutrient-controlled Developmental Response in Dictyostelium

    PubMed Central

    Cherix, Nathalie; Froquet, Romain; Charette, Steve J.; Blanc, Cédric; Letourneur, François

    2006-01-01

    Dictyostelium amoebae grow as single cells but upon starvation they initiate multicellular development. Phg2 was characterized previously as a kinase controlling cellular adhesion and the organization of the actin cytoskeleton. Here we report that Phg2 also plays a role during the transition between growth and multicellular development, as evidenced by the fact that phg2 mutant cells can initiate development even in the presence of nutrients. Even at low cell density and in rich medium, phg2 mutant cells express discoidin, one of the earliest predevelopmental markers. Complementation studies indicate that, in addition to the kinase domain, the core region of Phg2 is involved in the initiation of development. In this region, a small domain contiguous with a previously described ras-binding domain was found to interact with the Dictyostelium ortholog of the mammalian adhesion-regulating molecule (ADRM1). In addition, adrm1 knockout cells also exhibit abnormal initiation of development. These results suggest that a Phg2-Adrm1 signaling pathway is involved in the control of the transition from growth to differentiation in Dictyostelium. Phg2 thus plays a dual role in the control of cellular adhesion and initiation of development. PMID:16987957

  16. Assessment of Antioxidant and Cytoprotective Potential of Jatropha (Jatropha curcas) Grown in Southern Italy

    PubMed Central

    Papalia, Teresa; Barreca, Davide; Panuccio, Maria Rosaria

    2017-01-01

    Jatropha (Jatropha curcas L.) is a plant native of Central and South America, but widely distributed in the wild or semi-cultivated areas in Africa, India, and South East Asia. Although studies are available in literature on the polyphenolic content and bioactivity of Jatropha curcas L., no information is currently available on plants grown in pedoclimatic and soil conditions different from the autochthon regions. The aim of the present work was to characterize the antioxidant system developed by the plant under a new growing condition and to evaluate the polyphenol amount in a methanolic extract of leaves. Along with these analyses we have also tested the antioxidant and cytoprotective activities on lymphocytes. RP-HPLC-DAD analysis of flavonoids revealed a chromatographic profile dominated by the presence of flavone C-glucosydes. Vitexin is the most abundant identified compound followed by vicenin-2, stellarin-2, rhoifolin, and traces of isovitexin and isorhoifolin. Methanolic extract had high scavenging activity in all antioxidant assays tested and cytoprotective activity on lymphocytes exposed to tertz-buthylhydroperoxide. The results highlighted a well-defined mechanism of adaptation of the plant and a significant content of secondary metabolites with antioxidant properties, which are of interest for their potential uses, especially as a rich source of biologically active products. PMID:28335473

  17. R- and S-Equol have equivalent cytoprotective effects in Friedreich’s Ataxia

    PubMed Central

    2012-01-01

    Background Estradiol (E2) is a very potent cytoprotectant against a wide variety of cellular insults in numerous different cell models, including a Friedreich’s ataxia (FRDA) model. Previously, we demonstrated that estrogen-like compounds are able to prevent cell death in an FRDA model independent of any known estrogen receptor (ER) by reducing reactive oxygen species (ROS) and the detrimental downstream effects of ROS buildup including oxidative damage to proteins and lipids and impaired mitochondrial function. Results We have previously demonstrated by western blot that our cell model lacks ERα and expresses only very low levels of ERβ. Using L-buthionine (S,R)-sulfoximine (BSO) to induce oxidative stress in human FRDA fibroblasts, we determine the potency and efficacy of the soy-derived ERβ agonist S-equol and its ERα-preferring enantiomer, R-equol in vitro on cell viability and ROS accumulation. Here we demonstrate that these equol biphenolic compounds, while significantly less potent and efficacious than E2, provide statistically similar attenuation of ROS and cytoprotection against a BSO-induced oxidative insult. Conclusions These preliminary data demonstrate that estrogen and soy-derived equols could have a beneficial effect in delaying the onset and decreasing the severity of symptoms in FRDA patients by an antioxidant mechanism. In addition, these data confirm that the protection seen previously with E2 was indeed unrelated to ER binding. PMID:23088310

  18. Possible cytoprotective mechanism in rats of D-002, an anti-ulcerogenic product isolated from beeswax.

    PubMed

    Carbajal, D; Molina, V; Valdés, S; Arruzazabala, L; Rodeiro, I; Más, R; Magraner, J

    1996-08-01

    D-002 is an anti-ulcerogenic product, isolated from beeswax, which consists of a well-defined mixture of higher primary aliphatic alcohols. It is highly effective against ethanol-induced ulcers. This study was designed to determine if D-002 shows cytoprotective properties on gastric mucosa in ethanol-induced ulcers. The involvement of endogenous prostaglandins in the protective effect of D-002 was also investigated. When a subulcerogenic dose of indomethacin (10 mg kg-1) was injected simultaneously with oral administration of ethanol, oral pre-treatment with D-002 (5-100 mg kg-1) partially inhibited the gastric protection. D-002 (5 and 25 mg kg-1) administered to normal rats significantly increased the soluble mucus content and also prevented its reduction in rats with ethanol-induced ulcers. In addition, D-002 administered at 5 and 25 mg kg-1 prevented the increase of vascular permeability induced by ethanol (60%) and reduced the concentration of thromboxane B2 (TXB2) in gastric mucosa of rats with ethanol-induced ulcers. These results support the hypothesis that the anti-ulcerogenic properties of D-002 could be related to a cytoprotective mechanism.

  19. Bioactive Flavonoids, Antioxidant Behaviour, and Cytoprotective Effects of Dried Grapefruit Peels (Citrus paradisi Macf.)

    PubMed Central

    Castro-Vazquez, Lucia; Alañón, María Elena; Rodríguez-Robledo, Virginia; Pérez-Coello, María Soledad; Hermosín-Gutierrez, Isidro; Díaz-Maroto, María Consuelo; Jordán, Joaquín; Galindo, María Francisca; Arroyo-Jiménez, María del Mar

    2016-01-01

    Grapefruit (Citrus paradisi Macf.) is an important cultivar of the Citrus genus which contains a number of nutrients beneficial to human health. The objective of the present study was to evaluate changes in bioactive flavonoids, antioxidant behaviour, and in vitro cytoprotective effect of processed white and pink peels after oven-drying (45°C–60°C) and freeze-drying treatments. Comparison with fresh grapefruit peels was also assessed. Significant increases in DPPH, FRAPS, and ABTS values were observed in dried grapefruit peel samples in comparison with fresh peels, indicating the suitability of the treatments for use as tools to greatly enhance the antioxidant potential of these natural byproducts. A total of thirteen flavonoids were quantified in grapefruit peel extracts by HPLC-MS/MS. It was found that naringin, followed by isonaringin, was the main flavonoid occurring in fresh, oven-dried, and freeze-dried grapefruit peels. In vivo assay revealed that fresh and oven-dried grapefruit peel extracts (45°C) exerted a strong cytoprotective effect on SH-SY5Y neuroblastoma cell lines at concentrations ranging within 0.1–0.25 mg/mL. Our data suggest that grapefruit (Citrus paradisi Macf.) peel has considerable potential as a source of natural bioactive flavonoids with outstanding antioxidant activity which can be used as agents in several therapeutic strategies. PMID:26904169

  20. Pro- and antioxidant effects and cytoprotective potentials of nine edible vegetables in southwest Nigeria.

    PubMed

    Iwalewa, E O; Adewunmi, C O; Omisore, N O A; Adebanji, O A; Azike, C K; Adigun, A O; Adesina, O A; Olowoyo, O G

    2005-01-01

    Antioxidant and cytoprotective activities of boiled, cold, and methanolic extracts of nine edible vegetables in Southwest Nigeria were evaluated in the 1,1-diphenyl-2-picrylhydrazyl free radical assay and hemagglutination assay in bovine erythrocytes, respectively. Crassocephalum rubens showed the highest antioxidant activity (56.5%), Solanum americanum and Vernonia amygdalina exhibited moderate antioxidant activity (26.0-37.5% and 14.8-36.2%, respectively), Solanum macrocarpon, Telfaria occidentalis, Amaranthus hybridus, and Jatropha tanjorensis produced weak activity (1.6-15.8%, 1.6-7.7%, 2.8-6.62%, and 10.7-12.1%, respectively), while Celosia argentea and Talinum triangulare were pro-oxidants. It was also shown that extracts from all the vegetables are pro-oxidants at high concentrations of either 1 or 5 mg/mL or both. On the other hand, the studies on the cytoprotective effect showed that all the plant extracts demonstrated a very low hemagglutination titer value between 0.32 and 5.56 except S. americanum methanolic extract, which had a titer of 50.0. These results indicated correlation between the antioxidant properties and the hemagglutination values of these plant extracts; however, the membrane stabilizing capacity of the extracts supports the plants' antioxidant activity.

  1. Cytoprotective drugs in the prevention of ethanol-induced experimental gastric mucosal damage: a morphological study.

    PubMed

    Gaudio, E; Carpino, F; Petrozza, V; Bianchi, G; Alberico, P; Melis, M; Carlei, F; Lygidakis, N J

    1993-04-01

    Various so-called "cytoprotective" agents (sucralfate, carbenoxolone, 16,16-dimethyl-PGE2, sulglycotide and Maalox TC) have been tested on rats, with the aim of quantifying their capability to prevent ethanol-induced gastric mucosal damage. Rats fasted for 48 hours received 1 ml of 80% ethanol by oral gavage, after prior oral treatment with placebo or one of the above-mentioned drugs u.i.d. for 5 consecutive days. Six hours after ethanol administration, the animals were sacrificed and the stomach was removed and processed for computerized macroscopic assessment of the damaged surface and for structural (light microscopy) and ultrastructural (scanning and transmission electron microscopy) studies. The results obtained demonstrate that ethanol injury caused extensive mucosal necrosis of the glandular region of the stomach, an event that was effectively reduced in rats treated with 16,16-dm-PGE2, carbenoxolone or sulglycotide. These drugs appeared to preserve the mucosa, with morphology comparable to that of normal noninjured rats - in contrast to the other drugs investigated. These data confirm the cytoprotective properties of sulglycotide in particular, which was the most potent agent for preventing the development of ethanol-induced acute lesions of the gastric mucosa.

  2. Cytoprotective Effect of Lygodium venustum Sw. (Lygodiaceae) against Mercurium Chloride Toxicity.

    PubMed

    Figueredo, Fernando G; Lima, Luciene F; Morais-Braga, Maria Flaviana B; Tintino, Saulo R; Farias, Pablo A M; Matias, Edinardo F F; Costa, José Galberto M; Menezes, Irwin R A; Pereira, Raimundo L S; Coutinho, Henrique D M

    2016-01-01

    Mercury is a very dangerous metal when humans come into contact with it, whether through the air or skin or by ingestion. The aim of this work was to investigate the possible effects of the ethanol extract and fractions of Lygodium venustum Sw. against mercurium chloride toxicity towards Escherichia coli strain ATCC25922. The polyphenols and flavonoids present in the extract and fractions were quantified in mg equivalent of gallic acid/g sample and mg equivalent of quercetin/g sample, respectively. The in vitro FRAP method demonstrated the antioxidant activity of the samples. The antibacterial activity of the natural products was evaluated by microdilution method and by assays to elucidate the possible cytoprotective action when combining the natural products samples and mercurium chloride, utilizing the extract and fractions at a subinhibitory concentration. The results obtained in this work indicate that the ethanol extract and fractions of L. venustum are an alternative source of natural products with cytoprotective action, where this protection is correlated with antioxidant and chelating activity, due to the presence of total phenols and flavonoids.

  3. Antioxidant, antibrowning, and cytoprotective activities of Ligustrum robustum (Rxob.) Blume extract.

    PubMed

    Yu, Zhi-Long; Zeng, Wei-Cai

    2013-09-01

    The antioxidant, antibrowning, and cytoprotective activities of Ligustrum robustum (Rxob.) Blume extract (LRE) were investigated and the main antioxidant component was isolated and identified. With its high content of phenols and flavonoids, the LRE showed remarkable antioxidant capacity to scavenge free radicals in vitro and to inhibit oil oxidation in a peanut oil system. Moreover, LRE was observed to inhibit tyrosinase action and browning of fresh-cut apple slices effectively. Furthermore, the cytoprotective activity of LRE was evaluated in a human intestine model using Caco-2 cell lines. According to the activity-guided isolation and identification, by using column chromatography, high-performance liquid chromatography, time-of-flight mass spectrometry, and nuclear magnetic resonance analyses, ursolic acid was characterized as the main antioxidant component of LRE; it showed the strongest free radical-scavenging activity. The results suggested that L. robustum (Rxob.) Blume could be a new resource for preparing functional food and nutraceutical products for use in food and pharmacology industries.

  4. Pivotal Cytoprotective Mediators and Promising Therapeutic Strategies for Endothelial Progenitor Cell-Based Cardiovascular Regeneration

    PubMed Central

    Kim, Sujin

    2016-01-01

    Cardiovascular diseases (CVDs), including atherosclerosis, stroke, and myocardial infarction, is a major cause of death worldwide. In aspects of cell therapy against CVD, it is generally accepted that endothelial progenitor cells (EPCs) are potent neovascular modulators in ischemic tissues. In response to ischemic injury signals, EPCs located in a bone marrow niche migrate to injury sites and form new vessels by secreting various vasculogenic factors including VEGF, SDF-1, and FGF, as well as by directly differentiating into endothelial cells. Nonetheless, in ischemic tissues, most of engrafted EPCs do not survive under harsh ischemic conditions and nutrient depletion. Therefore, an understanding of diverse EPC-related cytoprotective mediators underlying EPC homeostasis in ischemic tissues may help to overcome current obstacles for EPC-mediated cell therapy for CVDs. Additionally, to enhance EPC's functional capacity at ischemic sites, multiple strategies for cell survival should be considered, that is, preconditioning of EPCs with function-targeting drugs including natural compounds and hormones, virus mediated genetic modification, combined therapy with other stem/progenitor cells, and conglomeration with biomaterials. In this review, we discuss multiple cytoprotective mediators of EPC-based cardiovascular repair and propose promising therapeutic strategies for the treatment of CVDs. PMID:28090210

  5. Assessment of Antioxidant and Cytoprotective Potential of Jatropha (Jatropha curcas) Grown in Southern Italy.

    PubMed

    Papalia, Teresa; Barreca, Davide; Panuccio, Maria Rosaria

    2017-03-18

    Jatropha (Jatropha curcas L.) is a plant native of Central and South America, but widely distributed in the wild or semi-cultivated areas in Africa, India, and South East Asia. Although studies are available in literature on the polyphenolic content and bioactivity of Jatropha curcas L., no information is currently available on plants grown in pedoclimatic and soil conditions different from the autochthon regions. The aim of the present work was to characterize the antioxidant system developed by the plant under a new growing condition and to evaluate the polyphenol amount in a methanolic extract of leaves. Along with these analyses we have also tested the antioxidant and cytoprotective activities on lymphocytes. RP-HPLC-DAD analysis of flavonoids revealed a chromatographic profile dominated by the presence of flavone C-glucosydes. Vitexin is the most abundant identified compound followed by vicenin-2, stellarin-2, rhoifolin, and traces of isovitexin and isorhoifolin. Methanolic extract had high scavenging activity in all antioxidant assays tested and cytoprotective activity on lymphocytes exposed to tertz-buthylhydroperoxide. The results highlighted a well-defined mechanism of adaptation of the plant and a significant content of secondary metabolites with antioxidant properties, which are of interest for their potential uses, especially as a rich source of biologically active products.

  6. Do sensory neurons mediate adaptive cytoprotection of gastric mucosa against bile acid injury?

    PubMed

    Mercer, D W; Ritchie, W P; Dempsey, D T

    1992-01-01

    Pretreatment with the mild irritant 1 mmol acidified taurocholate protects the gastric mucosa from the injury induced by the subsequent application of 5 mmol acidified taurocholate, a phenomenon referred to as "adaptive cytoprotection." How this occurs remains an enigma. The purpose of this study was to investigate the role of sensory neurons and mucus secretion in this phenomenon. Prior to injury with 5 mmol acidified taurocholate (pH 1.2), the stomachs of six groups of rats were subjected to the following protocol. Two groups were topically pretreated with either saline or the mild irritant 1 mmol acidified taurocholate. Two other groups received the topical anesthetic 1% lidocaine prior to pretreatment with either saline or 1 mmol acidified taurocholate. The last two groups got the mucolytic agent 10% N-acetylcysteine (NAC) after pretreatment with either saline or 1 mmol acidified taurocholate. Injury was assessed by measuring net transmucosal ion fluxes, luminal appearance of deoxyribonucleic acid (DNA), and gross and histologic injury. Pretreatment with the mild irritant 1 mmol acidified taurocholate significantly decreased bile acid-induced luminal ion fluxes and DNA accumulation, suggesting mucosal protection (corroborated by gross and histologic injury analysis). This effect was negated by lidocaine but not by NAC. Thus, it appears that sensory neurons, and not increased mucus secretion, play a critical role in adaptive cytoprotection.

  7. Cytoprotective Effect of Lygodium venustum Sw. (Lygodiaceae) against Mercurium Chloride Toxicity

    PubMed Central

    Figueredo, Fernando G.; Lima, Luciene F.; Morais-Braga, Maria Flaviana B.; Tintino, Saulo R.; Farias, Pablo A. M.; Matias, Edinardo F. F.; Costa, José Galberto M.; Menezes, Irwin R. A.; Pereira, Raimundo L. S.

    2016-01-01

    Mercury is a very dangerous metal when humans come into contact with it, whether through the air or skin or by ingestion. The aim of this work was to investigate the possible effects of the ethanol extract and fractions of Lygodium venustum Sw. against mercurium chloride toxicity towards Escherichia coli strain ATCC25922. The polyphenols and flavonoids present in the extract and fractions were quantified in mg equivalent of gallic acid/g sample and mg equivalent of quercetin/g sample, respectively. The in vitro FRAP method demonstrated the antioxidant activity of the samples. The antibacterial activity of the natural products was evaluated by microdilution method and by assays to elucidate the possible cytoprotective action when combining the natural products samples and mercurium chloride, utilizing the extract and fractions at a subinhibitory concentration. The results obtained in this work indicate that the ethanol extract and fractions of L. venustum are an alternative source of natural products with cytoprotective action, where this protection is correlated with antioxidant and chelating activity, due to the presence of total phenols and flavonoids. PMID:27034899

  8. Bioactive Flavonoids, Antioxidant Behaviour, and Cytoprotective Effects of Dried Grapefruit Peels (Citrus paradisi Macf.).

    PubMed

    Castro-Vazquez, Lucia; Alañón, María Elena; Rodríguez-Robledo, Virginia; Pérez-Coello, María Soledad; Hermosín-Gutierrez, Isidro; Díaz-Maroto, María Consuelo; Jordán, Joaquín; Galindo, María Francisca; Arroyo-Jiménez, María Del Mar

    2016-01-01

    Grapefruit (Citrus paradisi Macf.) is an important cultivar of the Citrus genus which contains a number of nutrients beneficial to human health. The objective of the present study was to evaluate changes in bioactive flavonoids, antioxidant behaviour, and in vitro cytoprotective effect of processed white and pink peels after oven-drying (45°C-60°C) and freeze-drying treatments. Comparison with fresh grapefruit peels was also assessed. Significant increases in DPPH, FRAPS, and ABTS values were observed in dried grapefruit peel samples in comparison with fresh peels, indicating the suitability of the treatments for use as tools to greatly enhance the antioxidant potential of these natural byproducts. A total of thirteen flavonoids were quantified in grapefruit peel extracts by HPLC-MS/MS. It was found that naringin, followed by isonaringin, was the main flavonoid occurring in fresh, oven-dried, and freeze-dried grapefruit peels. In vivo assay revealed that fresh and oven-dried grapefruit peel extracts (45°C) exerted a strong cytoprotective effect on SH-SY5Y neuroblastoma cell lines at concentrations ranging within 0.1-0.25 mg/mL. Our data suggest that grapefruit (Citrus paradisi Macf.) peel has considerable potential as a source of natural bioactive flavonoids with outstanding antioxidant activity which can be used as agents in several therapeutic strategies.

  9. Control of chicken CR1 retrotransposons is independent of Dicer-mediated RNA interference pathway

    PubMed Central

    Lee, Sung-Hun; Eldi, Preethi; Cho, Soo-Young; Rangasamy, Danny

    2009-01-01

    Background Dicer is an RNase III-ribonuclease that initiates the formation of small interfering RNAs as a defence against genomic parasites such as retrotransposons. Despite intensive characterization in mammalian species, the biological functions of Dicer in controlling retrotransposable elements of the non-mammalian vertebrate are poorly understood. In this report, we examine the role of chicken Dicer in controlling the activity of chicken CR1 retrotransposable elements in a chicken-human hybrid DT40 cell line employing a conditional loss-of-Dicer function. Results Retrotransposition is detrimental to host genome stability and thus eukaryotic cells have developed mechanisms to limit the expansion of retrotransposons by Dicer-mediated RNAi silencing pathways. However, the mechanisms that control the activity and copy numbers of transposable elements in chicken remain unclear. Here, we describe how the loss of Dicer in chicken cells does not reactivate endogenous chicken CR1 retrotransposons with impaired RNAi machinery, suggesting that the control of chicken CR1 is independent of Dicer-induced RNAi silencing. In contrast, upon introduction of a functionally active human L1 retrotransposable element that contains an active 5' UTR promoter, the Dicer-deficient chicken cells show a strong increase in the accumulation of human L1 transcripts and retrotransposition activity, highlighting a major difference between chicken CR1 and other mammalian L1 retrotransposons. Conclusion Our data provide evidence that chicken CR1 retrotransposons, unlike their mammalian L1 counterparts, do not undergo retrotransposition because most CR1 retrotransposons are truncated or mutated at their 5'UTR promoters and thus are not subjected to Dicer-mediated RNAi-silencing control. PMID:19691826

  10. Quantum optimal control pathways of ozone isomerization dynamics subject to competing dissociation: A two-state one-dimensional model

    SciTech Connect

    Kurosaki, Yuzuru; Ho, Tak-San Rabitz, Herschel

    2014-02-28

    We construct a two-state one-dimensional reaction-path model for ozone open → cyclic isomerization dynamics. The model is based on the intrinsic reaction coordinate connecting the cyclic and open isomers with the O{sub 2} + O asymptote on the ground-state {sup 1}A{sup ′} potential energy surface obtained with the high-level ab initio method. Using this two-state model time-dependent wave packet optimal control simulations are carried out. Two possible pathways are identified along with their respective band-limited optimal control fields; for pathway 1 the wave packet initially associated with the open isomer is first pumped into a shallow well on the excited electronic state potential curve and then driven back to the ground electronic state to form the cyclic isomer, whereas for pathway 2 the corresponding wave packet is excited directly to the primary well of the excited state potential curve. The simulations reveal that the optimal field for pathway 1 produces a final yield of nearly 100% with substantially smaller intensity than that obtained in a previous study [Y. Kurosaki, M. Artamonov, T.-S. Ho, and H. Rabitz, J. Chem. Phys. 131, 044306 (2009)] using a single-state one-dimensional model. Pathway 2, due to its strong coupling to the dissociation channel, is less effective than pathway 1. The simulations also show that nonlinear field effects due to molecular polarizability and hyperpolarizability are small for pathway 1 but could become significant for pathway 2 because much higher field intensity is involved in the latter. The results suggest that a practical control may be feasible with the aid of a few lowly excited electronic states for ozone isomerization.

  11. Quantum optimal control pathways of ozone isomerization dynamics subject to competing dissociation: a two-state one-dimensional model.

    PubMed

    Kurosaki, Yuzuru; Ho, Tak-San; Rabitz, Herschel

    2014-02-28

    We construct a two-state one-dimensional reaction-path model for ozone open → cyclic isomerization dynamics. The model is based on the intrinsic reaction coordinate connecting the cyclic and open isomers with the O2 + O asymptote on the ground-state (1)A(') potential energy surface obtained with the high-level ab initio method. Using this two-state model time-dependent wave packet optimal control simulations are carried out. Two possible pathways are identified along with their respective band-limited optimal control fields; for pathway 1 the wave packet initially associated with the open isomer is first pumped into a shallow well on the excited electronic state potential curve and then driven back to the ground electronic state to form the cyclic isomer, whereas for pathway 2 the corresponding wave packet is excited directly to the primary well of the excited state potential curve. The simulations reveal that the optimal field for pathway 1 produces a final yield of nearly 100% with substantially smaller intensity than that obtained in a previous study [Y. Kurosaki, M. Artamonov, T.-S. Ho, and H. Rabitz, J. Chem. Phys. 131, 044306 (2009)] using a single-state one-dimensional model. Pathway 2, due to its strong coupling to the dissociation channel, is less effective than pathway 1. The simulations also show that nonlinear field effects due to molecular polarizability and hyperpolarizability are small for pathway 1 but could become significant for pathway 2 because much higher field intensity is involved in the latter. The results suggest that a practical control may be feasible with the aid of a few lowly excited electronic states for ozone isomerization.

  12. Flux analysis and control of the central metabolic pathways in Escherichia coli.

    PubMed

    Holms, H

    1996-12-01

    The growth of the bacterial cell involves the co-ordination of the fluxes of carbon into a considerable diversity of products that are the components of the cell. Fortunately the monomers from which the cell's polymers are made are themselves synthesised from a relatively small group of precursors that are the products of the central metabolic pathways. This simplification renders cell metabolism accessible to flux analysis, a method for handling experimental data to derive metabolic fluxes. Through such analysis of the growth of Escherichia coli ML308 on 11 single carbon sources in batch, turbidostat or chemostat culture general patterns are discernible. Most significant among these are that growth on different carbon sources is achieved without any obvious enzyme acting as a regulator of metabolic flux, except when acetate is the sole source of carbon. In this case a junction is created at which iso citrate dehydrogenase (ICDH) and isocitrate lyase (ICL) compete for their common substrate and this competition is resolved by partial inactivation of ICDH to match flux through ICL and this balance limits growth rate. In this sense, flux through ICDH and ICL is 'rate-limiting'. Uptake of six of the remaining carbon inputs exceeds the capacity of the central metabolic pathways (CMPs) to sustain flux to the precursors required for growth and the CMPs are balanced by excretion of acetate. Restriction of carbon uptake by chemostat progressively diminishes growth rate and acetate excretion until acetate excretion is prevented. For the four remaining carbon sources, uptake is apparently restricted and the products are biomass, carbon dioxide and water. Carbon sources feeding the phosphorylated parts of the CMPs flux relatively more carbon to precursors (Pre-C) than CO2 when compared with carbon sources which feed into the non-phosphorylated pathways. Pre-C/CO2 ratios for the former are 1.73-3.91 and for the latter are 0.46-0.78. Flux analysis of all 11 carbon sources shows

  13. Control of thrombopoietin-induced megakaryocytic differentiation by the mitogen-activated protein kinase pathway.

    PubMed Central

    Rouyez, M C; Boucheron, C; Gisselbrecht, S; Dusanter-Fourt, I; Porteu, F

    1997-01-01

    Thrombopoietin (TPO) is the major regulator of both growth and differentiation of megakaryocytes. We previously showed that both functions can be generated by TPO in the megakaryoblastic cell line UT7, in which murine Mpl was introduced, and are independently controlled by distinct regions of the cytoplasmic domain of Mpl. Particularly, residues 71 to 94 of this domain (deleted in the mutant mpl delta3) were found to be required for megakaryocytic maturation but dispensable for proliferation. We show here that TPO-induced differentiation in UT7 cells is tightly dependent on a strong, long-lasting activation of the mitogen-activated protein kinase (MAPK) pathway. Indeed, (i) in UT7-mpl cells, TPO induced a strong activation of extracellular signal-regulated kinases (ERK) which was persistent until at least 4 days in TPO-containing medium; (ii) a specific MAPK kinase (MEK) inhibitor inhibited TPO-induced megakaryocytic gene expression; (iii) the Mpl mutant mpl delta3, which displayed no maturation activity, transduced only a weak and transient ERK activation in UT7 cells; and (iv) TPO-induced megakaryocytic differentiation in UT7-mpl delta3 cells was partially restored by expression of a constitutively activated mutant of MEK. The capacity of TPO to trigger a strong and prolonged MAPK signal depended on the cell in which Mpl was introduced. In BAF3-mpl cells, TPO triggered a weak and transient ERK activation, similar to that induced in UT7-mpl delta3 cells. In these cells, no difference in MAPK activation was found between normal Mpl and mpl delta3. Thus, depending on the cellular context, several distinct regions of the cytoplasmic domain of Mpl and signaling pathways may contribute to generate quantitative variations in MAPK activation. PMID:9271377

  14. σS Controls Multiple Pathways Associated with Intracellular Multiplication of Legionella pneumophila▿ †

    PubMed Central

    Hovel-Miner, Galadriel; Pampou, Sergey; Faucher, Sebastien P.; Clarke, Margaret; Morozova, Irina; Morozov, Pavel; Russo, James J.; Shuman, Howard A.; Kalachikov, Sergey

    2009-01-01

    Legionella pneumophila is the causative agent of the severe and potentially fatal pneumonia Legionnaires' disease. L. pneumophila is able to replicate within macrophages and protozoa by establishing a replicative compartment in a process that requires the Icm/Dot type IVB secretion system. The signals and regulatory pathways required for Legionella infection and intracellular replication are poorly understood. Mutation of the rpoS gene, which encodes σS, does not affect growth in rich medium but severely decreases L. pneumophila intracellular multiplication within protozoan hosts. To gain insight into the intracellular multiplication defect of an rpoS mutant, we examined its pattern of gene expression during exponential and postexponential growth. We found that σS affects distinct groups of genes that contribute to Legionella intracellular multiplication. We demonstrate that rpoS mutants have a functional Icm/Dot system yet are defective for the expression of many genes encoding Icm/Dot-translocated substrates. We also show that σS affects the transcription of the cpxR and pmrA genes, which encode two-component response regulators that directly affect the transcription of Icm/Dot substrates. Our characterization of the L. pneumophila small RNA csrB homologs, rsmY and rsmZ, introduces a link between σS and the posttranscriptional regulator CsrA. We analyzed the network of σS-controlled genes by mutational analysis of transcriptional regulators affected by σS. One of these, encoding the L. pneumophila arginine repressor homolog gene, argR, is required for maximal intracellular growth in amoebae. These data show that σS is a key regulator of multiple pathways required for L. pneumophila intracellular multiplication. PMID:19218380

  15. Final Technical Report: Genetic and Molecular Analysis of a new control pathway in assimilate partitioning.

    SciTech Connect

    Bush, Daniel, R.

    2009-03-10

    Assimilate partitioning refers to the systemic distribution of photoassimilate from sites of primary assimilation (source tissue) to import-dependent tissues and organs (sinks). One of the defining questions in this area is how plants balance source productivity with sink demand. We discovered a sucrose-sensing signal transduction pathway that controls the activity of BvSUT1, a proton-sucrose symporter in sugar beet leaf tissue. Sucrose symporters are responsible for sucrose accumulation in the phloem of many plants and, therefore, they mediate the pivotal step in the long-distance transport of photoassimilate to non-photosynthetic tissues, such as roots and seed. We previously showed that sucrose transport activity is directly proportional to the transcription rate of BvSUT1 and that symporter mRNA and protein have high rates of turnover with half-lives on the order of 2 h. We further demonstrated that symporter transcription is regulated by sucrose levels in the leaf and that sucrose-dependent regulation of BvSUT1 transcription is mediated, at least in part, by a protein phosphorylation relay pathway. The goal of the experiments during this current grant were to use genetic and molecular approaches to identify essential components of this vital regulatory system. The initial objectives were to: (1) to characterize Arabidopsis mutants we've isolated that are resistant to growth inhibition by sucrose analogues that are recognized by the sucrose-sensor, (2) to screen for loss of function mutants in BvSUT1-promoter:luciferase transgenic plants that no longer respond to sucrose accumulation in the leaf using non-destructive visualization of luciferase activity, (3) to use gel mobility-shift assays and nuclease protection experiments to identify cis elements in the symporter promoter and DNA-binding proteins that are involved in sucrose regulation of symporter expression.

  16. Control of Diapause in Calanid Copepods: Identification of Regulatory Pathways using In Silico Data Mining

    NASA Astrophysics Data System (ADS)

    Lenz, P. H.; Roncalli, V.; Hopcroft, R. R.; Christie, A. E.

    2016-02-01

    As water temperatures and seasonal cycles change with global warming, questions are being raised on how these factors might affect the life cycles of copepods in the family Calanidae. These species depend on the completion of a seasonal diapause for the annual recruitment of the spring population. Diapause is a developmental program that includes induction, preparation, initiation, maintenance and termination. A lipid hypothesis has been proposed to explain the regulation of diapause in Calanus finmarchicus. While lipids may be critical for the diapause program, lipid metabolism is typically under neuroendocrine control. In insects, there is an extensive literature showing that juvenile hormone, ecdysteroids, and many neuropeptides are involved in the regulation of diapause. In particular, insulin signaling has been proposed as a key component in the diapause phenotype in a wide variety of insects, and through the actions of the transcription factor FOXO, many features of diapause can be linked to the insulin pathway, e.g., fat accumulation and enhancement of stress tolerance. Using the insects as models, we identified transcripts and predicted the protein components of the insulin/FOXO pathway (e.g., insulin-like peptide precursors, insulin receptors, juvenile hormone acid O-methyltransferase and FOXO), as well as a wide variety of neuropeptides (e.g., members of the diapause hormone family) and other proteins (e.g., those putatively involved in biological timing such as circadian and seasonal rhythmicity) that might be involved in the regulation of lipid metabolism and diapause in the calanid copepods C. finmarchicus and Neocalanus flemingeri. Our goal is to use the identified transcripts to start to understand the physiological processes underlying diapause in these calanids.

  17. Chemoselective reduction and oxidation of ketones in water through control of the electron transfer pathway

    PubMed Central

    Kim, Sun Min; Yoo, Ho Sung; Hosono, Hideo; Yang, Jung Woon; Kim, Sung Wng

    2015-01-01

    The selective synthesis of different products from the same starting materials in water, which is the most abundant solvent in nature, is a crucial issue as it maximizes the utilization of materials. Realizing such reactions for ketones is of considerable importance because numerous organic functionalities can be obtained via nucleophilic addition reactions. Herein, we report chemoselective reduction and oxidation reactions of 1,2-diketones in water, which initiates anionic electron transfer from the inorganic electride [Ca24Al28O64]4+·4e−, through controlling the pathway of the electrons to substrates. The generation of different radical species for transient intermediates was the key process required to control the reaction selectivity, which was achieved by reacting the anionic electrons with either diketones or O2, leading to the formation of ketyl dianion and superoxide radicals in the reduction and oxidation reactions, respectively. This methodology that utilizes electrides may provide an alternative to the pulse radiolysis of water in synthetic chemistry. PMID:26020413

  18. Synthetic Control of Kinetic Reaction Pathway and Cationic Ordering in High-Ni Layered Oxide Cathodes

    DOE PAGES

    Wang, Dawei; Kou, Ronghui; Ren, Yang; ...

    2017-08-25

    Nickel-rich layered transition metal oxides, LiNi1-x(MnCo)xO2 (1-x ≥ 0.5), are appealing candidates for cathodes in next-generation lithium-ion batteries (LIBs) for electric vehicles and other large-scale applications, due to their high capacity and low cost. However, synthetic control of the structural ordering in such a complex quaternary system has been a great challenge, especially in the presence of high Ni content. Herein, synthesis reactions for preparing layered LiNi0.7Mn0.15Co0.15O2 (NMC71515) by solid-state methods are investigated through a combination of time-resolved in situ high-energy X-ray diffraction and absorption spectroscopy measurements. The real-time observation reveals a strong temperature dependence of the kinetics of cationicmore » ordering in NMC71515 as a result of thermal-driven oxidation of transition metals and lithium/oxygen loss that concomitantly occur during heat treatment. Through synthetic control of the kinetic reaction pathway, a layered NMC71515 with low cationic disordering and a high reversible capacity is prepared in air. The findings may help to pave the way for designing high-Ni layered oxide cathodes for LIBs« less

  19. Quality Control Pathways for Nucleus-Encoded Eukaryotic tRNA Biosynthesis and Subcellular Trafficking.

    PubMed

    Hopper, Anita K; Huang, Hsiao-Yun

    2015-06-01

    tRNAs perform an essential role in translating the genetic code. They are long-lived RNAs that are generated via numerous posttranscriptional steps. Eukaryotic cells have evolved numerous layers of quality control mechanisms to ensure that the tRNAs are appropriately structured, processed, and modified. We describe the known tRNA quality control processes that check tRNAs and correct or destroy aberrant tRNAs. These mechanisms employ two types of exonucleases, CCA end addition, tRNA nuclear aminoacylation, and tRNA subcellular traffic. We arrange these processes in order of the steps that occur from generation of precursor tRNAs by RNA polymerase (Pol) III transcription to end maturation and modification in the nucleus to splicing and additional modifications in the cytoplasm. Finally, we discuss the tRNA retrograde pathway, which allows tRNA reimport into the nucleus for degradation or repair. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  20. Tamarix gallica phenolics protect IEC-6 cells against H2O2 induced stress by restricting oxidative injuries and MAPKs signaling pathways.

    PubMed

    Bettaib, Jamila; Talarmin, Hélène; Droguet, Mickaël; Magné, Christian; Boulaaba, Mondher; Giroux-Metges, Marie-Agnès; Ksouri, Riadh

    2017-05-01

    Polyphenolic compounds gained interest in the pharmaceutical research area due to their beneficial properties. Herein, antioxidant and cytoprotective capacities of T. gallica extract on H2O2-challenged rat small intestine epithelial cells were investigated. To set stress conditions, IEC-6 cultures were challenged with numerous H2O2 doses and durations. Then, 40μM H2O2 during 4h were selected to assess the cytoprotective effect of different T. gallica extract concentrations. Oxidative parameters, measured through CAT and SOD activities as well as MDA quantification were assessed. In addition, the expression of possibly involved MAPKs was also valued. Main results reported that T. gallica was rich in polyphenols and exhibited an important antioxidant activity (DPPH Assay, IC50=6μgmL(-1); ABTS(+) test, IC50=50μgmL(-1); Fe-reducing power, EC50=100μgmL(-1)). The exposure of IEC-6 cultures to 40μM H2O2 during 4h caused oxidative stress manifested by (i) over 70% cell mortality, (ii) over-activity of CAT (246%), (iii) excess in MDA content (18.4nmolmg(-1)) and (iiii) a trigger of JNK phosphorylation. Pretreatment with T. gallica extract, especially when used at 0.25μgmL(-1), restored cell viability to 122%, and normal cell morphology in H2O2-chalenged cells. In addition, this extract normalized CAT activity and MDA content (100% and 14.7nmolmg(-1), respectively) to their basal levels as compared to control cells. Furthermore, stopping cell death seems to be due to dephosphorylated JNK MAPK exerted by T. gallica bioactive compounds. In all, T. gallica components provided a cross-talk between regulatory pathways leading to an efficient cytoprotection against harmful oxidative stimulus. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  1. Cytoprotective effects of amifostine, ascorbic acid and N-acetylcysteine against methotrexate-induced hepatotoxicity in rats

    PubMed Central

    Akbulut, Sami; Elbe, Hulya; Eris, Cengiz; Dogan, Zumrut; Toprak, Gulten; Otan, Emrah; Erdemli, Erman; Turkoz, Yusuf

    2014-01-01

    AIM: To investigate the potential role of oxidative stress and the possible therapeutic effects of N-acetyl cysteine (NAC), amifostine (AMF) and ascorbic acid (ASC) in methotrexate (MTX)-induced hepatotoxicity. METHODS: An MTX-induced hepatotoxicity model was established in 44 male Sprague Dawley rats by administration of a single intraperitoneal injection of 20 mg/kg MTX. Eleven of the rats were left untreated (Model group; n = 11), and the remaining rats were treated with a 7-d course of 50 mg/kg per day NAC (MTX + NAC group; n = 11), 50 mg/kg per single dose AMF (MTX + AMF group; n = 11), or 10 mg/kg per day ASC (MTX + ASC group; n = 11). Eleven rats that received no MTX and no treatments served as the negative control group. Structural and functional changes related to MTX- and the various treatments were assessed by histopathological analysis of liver tissues and biochemical assays of malondialdehyde (MDA), superoxide dismutase (SOD), catalase, glutathione (GSH) and xanthine oxidase activities and of serum levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and total bilirubin. RESULTS: Exposure to MTX caused structural and functional hepatotoxicity, as evidenced by significantly worse histopathological scores [median (range) injury score: control group: 1 (0-3) vs 7 (6-9), P = 0.001] and significantly higher MDA activity [409 (352-466) nmol/g vs 455.5 (419-516) nmol/g, P < 0.05]. The extent of MTX-induced perturbation of both parameters was reduced by all three cytoprotective agents, but only the reduction in hepatotoxicity scores reached statistical significance [4 (3-6) for NAC, 4.5 (3-5) for AMF and 6 (5-6) for ASC; P = 0.001, P = 0.001 and P < 0.005 vs model group respectively]. Exposure to MTX also caused a significant reduction in the activities of GSH and SOD antioxidants in liver tissues [control group: 3.02 (2.85-3.43) μmol/g and 71.78 (61.88-97.81) U/g vs model group: 2.52 (2.07-3.34) μmol/g and 61.46 (58

  2. Polo kinase links the stress pathway to cell cycle control and tip growth in fission yeast.

    PubMed

    Petersen, Janni; Hagan, Iain M

    2005-05-26

    Stress-activated mitogen-activated protein kinase cascades instigate a range of changes to enable eukaryotic cells to cope with particular insults. In Schizosaccharomyces pombe these responses include the transcription of specific gene sets and inhibition of entry into mitosis. The S. pombe stress response pathway (SRP) also promotes commitment to mitosis in unperturbed cell cycles to allow cells to match their rate of division with nutrient availability. The nature of this SRP function in cell cycle control is unknown. Entry into mitosis is controlled by mitosis-promoting factor (MPF; Cdc2/cyclin B) activity. Inhibitory phosphorylation of Cdc2 by Wee1 kinase inactivates MPF until Cdc25 removes this phosphate to promote mitosis. The balance between Wee1 and Cdc25 activities is influenced by the recruitment of polo kinase (Plo1) to the spindle pole body (SPB). The SPB component Cut12 mediates this recruitment. Hyper-activating mutations in either cut12 or plo1 enable Cdc25-defective cells to enter mitosis. The hyperactive cut12.s11 mutation suppresses cdc25.22, as it promotes recruitment of active Plo1 to interphase SPBs. Here we show that the SRP promotes phosphorylation of Plo1 on Ser 402. In unperturbed cell cycles, SRP-mediated phosphorylation of Ser 402 promotes Plo1 recruitment to SPBs and thus commitment to mitosis. Ser 402 phosphorylation also ensures efficient reinitiation of cell tip growth and cell division during recovery from particular stresses. Thus, phosphorylation of Plo1 Ser 402 not only enables SRP signalling to modulate the timing of mitotic commitment in response to nutrient status in unperturbed cycles, but also promotes the return to normal cell cycle control after stress.

  3. Hippo pathway genes developed varied exon numbers and coevolved functional domains in metazoans for species specific growth control

    PubMed Central

    2013-01-01

    Background The Hippo pathway controls growth by mediating cell proliferation and apoptosis. Dysregulation of Hippo signaling causes abnormal proliferation in both healthy and cancerous cells. The Hippo pathway receives inputs from multiple developmental pathways and interacts with many tissue-specific transcription factors, but how genes in the pathway have evolved remains inadequately revealed. Results To explore the origin and evolution of Hippo pathway, we have extensively examined 16 Hippo pathway genes, including upstream regulators and downstream targets, in 24 organisms covering major metazoan phyla. From simple to complex organisms, these genes are varied in the length and number of exons but encode conserved domains with similar higher-order organization. The core of the pathway is more conserved than its upstream regulators and downstream targets. Several components, despite existing in the most basal metazoan sponges, cannot be convincingly identified in other species. Potential recombination breakpoints were identified in some genes. Coevolutionary analysis reveals that most functional domains in Hippo genes have coevolved with interacting functional domains in other genes. Conclusions The two essential upstream regulators cadherins fat and dachsous may have originated in the unicellular organism Monosiga brevicollis and evolved more significantly than the core of the pathway. Genes having varied numbers of exons in different species, recombination events, and the gain and loss of some genes indicate alternative splicing and species-specific evolution. Coevolution signals explain some species-specific loss of functional domains. These results significantly unveil the structure and evolution of the Hippo pathway in distant phyla and provide valuable clues for further examination of Hippo signaling. PMID:23547742

  4. Active control of electromagnetically induced transparency with dual dark mode excitation pathways using MEMS based tri-atomic metamolecules

    NASA Astrophysics Data System (ADS)

    Pitchappa, Prakash; Manjappa, Manukumara; Ho, Chong Pei; Singh, Ranjan; Singh, Navab; Lee, Chengkuo

    2016-11-01

    We report experimental results of the active switching of electromagnetically induced transparency (EIT) analogue by controlling the dark mode excitation pathways in a microelectromechanical system based tri-atomic metamolecule, operating in the terahertz spectral region. The tri-atomic metamolecule consists of two bright cut wire resonators (CWRs) on either side of the dark split ring resonators (SRRs). Each of the CWRs can independently excite the dark inductive-capacitive resonance mode of the SRRs through inductive coupling, and this allows for the dual pathways of dark mode excitation. The CWRs are made movable along the out-of-plane direction and electrically isolated to achieve selective reconfiguration. Hence, by controlling the physical position of these CWRs, the excitation pathways can be actively reconfigured. This enables the strong excitation of EIT analogue at 0.65 THz, only when one of the pathways is made accessible. Moreover, the transparency peak is completely modulated when both pathways are made either inaccessible or equally accessible. The proposed approach of realizing independent control of constituent resonators in a multi-resonator coupled system, enables the realization of efficient slow light devices and tunable high-Q resonators in terahertz spectral region.

  5. [Efficacy of the myocardium cytoprotection in patients with ischemic heart disease during extended operations on abdominal organs].

    PubMed

    Mosienko, B I

    2013-09-01

    The results of studying of the myocardium contractile capacity in patients, suffering the ischemic heart disease, while performing the extended operative interventions are presented. There was noted, that the indices of the myocardium contractile capacity witness its inhibition during traumatic stage of operation and in early postoperative period. There was established an important significance of the myocardium cytoprotection in preoperative preparation of the patients.

  6. Chemical constituents from aerial parts of Caryopteris incana and cytoprotective effects in human HepG2 cells.

    PubMed

    Park, Sunmi; Son, Min Jeong; Yook, Chang-Soo; Jin, Changbae; Lee, Yong Sup; Kim, Hyoung Ja

    2014-05-01

    An ethyl acetate fraction of the aerial parts of Caryopteris incana (Verbenaceae) showed potent cytoprotective effects against damage to HepG2 cells induced by tert-butylhydroperoxide (t-BHP). To search for hepatoprotective components of C. incana, various chromatographic separations of the ethyl acetate soluble fraction of C. incana led to isolation of three phenylpropanoid glycosides, 6‴-O-feruloylincanoside D, 6‴-O-sinapoylincanoside D and caryopteroside, and two iridoid glycosides, incanides A and B, together with 17 known compounds. Structures of these compounds were determined by spectroscopic analyses. The absolute stereochemistry of the caryopteroside was established with the help of circular dichroism data and in comparison with literature data. All isolated substances were determined for their cytoprotective effects against t-BHP-induced toxicity in HepG2 cells. Among the tested compounds, 6'-O-caffeoylacteoside exhibited the most potent cytoprotective activity with an IC50 value of 0.8±0.1 μM against t-BHP-induced toxicity. Structure-activity relationships of the assay results indicated an important role of the catechol moiety in phenylpropanoid, iridoid and flavonoid derivatives in eliciting cytoprotective effects. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Antioxidant and cytoprotective activities of Piper betle, Areca catechu, Uncaria gambir and betel quid with and without calcium hydroxide

    PubMed Central

    2013-01-01

    Background Betel quid chewing is a popular habit in Southeast Asia. It is believed that chewing betel quid could reduce stress, strengthen teeth and maintain oral hygiene. The aim of this study was to investigate the antioxidant and cytoprotective activities of each of the ingredients of betel quid and compared with betel quid itself (with and without calcium hydroxide). The correlation of their cytoprotective and antioxidant activities with phenolic content was also determined. Methods Five samples (betel leaf, areca nut, gambir, betel quid and betel quid containing calcium hydroxide) were extracted in deionized distilled water for 12 hours at 37°C. Antioxidant activities were evaluated for radical scavenging activity using DPPH assay, ferric reducing activity using FRAP assay and lipid peroxidation inhibition activity using FTC assay. Total phenolic content (TPC) was determined using Folin-Ciocalteu procedure. Phenolic composition was analyzed using LC-MS/MS. Cytoprotective activity towards human gingival fibroblast cells was examined using MTT assay. Results Among the ingredients of betel quid, gambir demonstrated the highest antioxidant (DPPH - IC50 = 6.4 ± 0.8 μg/mL, FRAP - 5717.8 ± 537.6 μmol Fe(II)/mg), total phenolic content (TPC - 1142.5 ± 106.8 μg TAE/mg) and cytoprotective (100.1 ± 4.6%) activities. Betel quid when compared with betel quid containing calcium hydroxide has higher antioxidant (DPPH - IC50 =59.4 ± 4.4 μg/mL, FRAP - 1022.2 ± 235.7 μmol Fe(II)/mg), total phenolic content (TPC - 140.0 ± 22.3 μg TAE/mg), and cytoprotective (113.5 ± 15.9%) activities. However, all of the five samples showed good lipid peroxidation inhibition compared to vitamin E. LC-MS/MS analysis revealed the presence of quinic acid as the major compound of gambir and betel quid. A positive correlation was observed between TPC and radical scavenging (r = 0.972), reducing power (r = 0.981) and cytoprotective

  8. Microbiota control of a tryptophan-AhR pathway in disease tolerance to fungi.

    PubMed

    Romani, Luigina; Zelante, Teresa; De Luca, Antonella; Iannitti, Rossana G; Moretti, Silvia; Bartoli, Andrea; Aversa, Franco; Puccetti, Paolo

    2014-11-01

    An increased understanding of the importance of microbiota in shaping the host's immune and metabolic activities has rendered fungal interactions with their hosts more complex than previously appreciated. The aryl hydrocarbon receptor (AhR) has a pivotal role in connecting tryptophan catabolism by microbial communities and the host's own pathway of tryptophan metabolite production with the orchestration of T-cell function. AhR activation by a Lactobacillus-derived AhR ligand leads to the production of IL-22 to the benefit of mucosal defense mechanisms, an activity upregulated in the absence of the host tryptophan catabolic enzyme, indoleamine 2,3-dioxygenase 1 (IDO1), which is required for protection from fungal diseases ("disease tolerance"). As AhR activation in turn leads to the activation-in a feedback fashion-of IDO1, the regulatory loop involving AhR and IDO1 may have driven the coevolution of commensal fungi with the mammalian immune system and the microbiota, to the benefit of host survival and fungal commensalism. This review will discuss the essential help the microbiota provides in controlling the balance between the dual nature of the fungal-host relationship, namely, commensalism vs. infection. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. INSIDE-OUT SIGNALING PATHWAYS FROM NUCLEAR ROS CONTROL PULMONARY INNATE IMMUNITY

    PubMed Central

    Choudhary, Sanjeev; Brasier, Allan R.

    2016-01-01

    The airway mucosa is responsible for mounting a robust innate immune response (IIR) upon encountering pathogen-associated molecular patterns. The IIR produces protective gene networks that stimulate neighboring epithelia and components of the immune system to trigger adaptive immunity. Little is currently known about how cellular reactive oxygen species (ROS) signaling is produced and cooperates in the IIR. We discuss recent discoveries on two nuclear ROS signaling pathways controlling innate immunity. Nuclear ROS oxidize guanine bases to produce mutagenic 8-oxoguanine, a lesion excised by 8-oxoguanine DNA glycosylase1/AP-lyase (OGG1). OGG1 forms a complex with the excised base, inducing its nuclear export. The cytoplasmic OGG1•8-oxoG complex functions as a guanine nucleotide exchange factor, triggering small GTPase signaling and activating phosphorylation of the NFκB/RelA transcription factor to induce immediate early gene expression. In parallel, nuclear ROS are detected by ataxia telangiectasia mutated (ATM), a PI3 kinase activated by ROS, triggering its nuclear export. ATM forms a scaffold with ribosomal S6 kinases, inducing RelA phosphorylation and resulting in transcription-coupled synthesis of type -I and –III interferons and CC and CXC chemokines. We propose that ATM and OGG1 are endogenous nuclear ROS sensors that transmit nuclear signals that coordinate with outside-in PRR signaling, regulating the IIR. PMID:26756522

  10. A photoactivable multi-inhibitor nanoliposome for tumour control and simultaneous inhibition of treatment escape pathways

    PubMed Central

    Spring, Bryan Q.; Sears, R. Bryan; Zheng, Lei Zak; Mai, Zhiming; Watanabe, Reika; Sherwood, Margaret E.; Schoenfeld, David A.; Pogue, Brian W.; Pereira, Stephen P.; Villa, Elizabeth; Hasan, Tayyaba

    2015-01-01

    Nanoscale drug delivery vehicles can facilitate multimodal therapies of cancer by promoting tumour-selective drug release. However, few are effective because cancer cells develop ways to resist and evade treatment. Here, we introduce a photoactivatable multi-inhibitor nanoliposome (PMIL) that imparts light-induced cytotoxicity in synchrony with photo-initiated and sustained release of inhibitors that suppress tumour regrowth and treatment escape signalling pathways. The PMIL consists of a nanoliposome doped with a photoactivatable chromophore (benzoporphyrin derivative, BPD) in the lipid bilayer, and a nanoparticle containing cabozantinib (XL184)—a multikinase inhibitor—encapsulated inside. Near infrared tumour irradiation, following intravenous PMIL administration, triggers photodynamic damage of tumour cells and microvessels, and simultaneously initiates release of XL184 inside the tumour. A single PMIL treatment achieves prolonged tumour reduction in two mouse models and suppresses metastatic escape in an orthotopic pancreatic tumour model. The PMIL offers new prospects for cancer therapy by enabling spatiotemporal control of drug release whilst reducing systemic drug exposure and associated toxicities. PMID:26780659

  11. The Diversity of the Pollen Tube Pathway in Plants: Toward an Increasing Control by the Sporophyte

    PubMed Central

    Lora, Jorge; Hormaza, José I.; Herrero, María

    2016-01-01

    Plants, unlike animals, alternate multicellular diploid, and haploid generations in their life cycle. While this is widespread all along the plant kingdom, the size and autonomy of the diploid sporophyte and the haploid gametophyte generations vary along evolution. Vascular plants show an evolutionary trend toward a reduction of the gametophyte, reflected both in size and lifespan, together with an increasing dependence from the sporophyte. This has resulted in an overlooking of the importance of the gametophytic phase in the evolution of higher plants. This reliance on the sporophyte is most notorious along the pollen tube journey, where the male gametophytes have to travel a long way inside the sporophyte to reach the female gametophyte. Along evolution, there is a change in the scenery of the pollen tube pathway that favors pollen competition and selection. This trend, toward apparently making complicated what could be simple, appears to be related to an increasing control of the sporophyte over the gametophyte with implications for understanding plant evolution. PMID:26904071

  12. A segregated neural pathway for prefrontal top-down control of tactile discrimination.

    PubMed

    Gogulski, Juha; Boldt, Robert; Savolainen, Petri; Guzmán-López, Jessica; Carlson, Synnöve; Pertovaara, Antti

    2015-01-01

    It has proven difficult to separate functional areas in the prefrontal cortex (PFC), an area implicated in attention, memory, and distraction handling. Here, we assessed in healthy human subjects whether PFC subareas have different roles in top-down regulation of sensory functions by determining how the neural links between the PFC and the primary somatosensory cortex (S1) modulate tactile perceptions. Anatomical connections between the S1 representation area of the cutaneous test site and the PFC were determined using probabilistic tractography. Single-pulse navigated transcranial magnetic stimulation of the middle frontal gyrus-S1 link, but not that of the superior frontal gyrus-S1 link, impaired the ability to discriminate between single and twin tactile pulses. The impairment occurred within a restricted time window and skin area. The spatially and temporally organized top-down control of tactile discrimination through a segregated PFC-S1 pathway suggests functional specialization of PFC subareas in fine-tuned regulation of information processing. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  13. Control of Ste6 recycling by ubiquitination in the early endocytic pathway in yeast.

    PubMed

    Krsmanovic, Tamara; Pawelec, Agnes; Sydor, Tobias; Kölling, Ralf

    2005-06-01

    We present evidence that ubiquitination controls sorting of the ABC-transporter Ste6 in the early endocytic pathway. The intracellular distribution of Ste6 variants with reduced ubiquitination was examined. In contrast to wild-type Ste6, which was mainly localized to internal structures, these variants accumulated at the cell surface in a polar manner. When endocytic recycling was blocked by Ypt6 inactivation, the ubiquitination deficient variants were trapped inside the cell. This indicates that the polar distribution is maintained dynamically through endocytic recycling and localized exocytosis ("kinetic polarization"). Ste6 does not appear to recycle through late endosomes, because recycling was not blocked in class E vps (vacuolar protein sorting) mutants (Deltavps4, Deltavps27), which are affected in late endosome function and in the retromer mutant Deltavps35. Instead, recycling was partially affected in the sorting nexin mutant Deltasnx4, which serves as an indication that Ste6 recycles through early endosomes. Enhanced recycling of wild-type Ste6 was observed in class D vps mutants (Deltapep12, Deltavps8, and Deltavps21). The identification of putative recycling signals in Ste6 suggests that recycling is a signal-mediated process. Endocytic recycling and localized exocytosis could be important for Ste6 polarization during the mating process.

  14. A photoactivable multi-inhibitor nanoliposome for tumour control and simultaneous inhibition of treatment escape pathways

    NASA Astrophysics Data System (ADS)

    Spring, Bryan Q.; Bryan Sears, R.; Zheng, Lei Zak; Mai, Zhiming; Watanabe, Reika; Sherwood, Margaret E.; Schoenfeld, David A.; Pogue, Brian W.; Pereira, Stephen P.; Villa, Elizabeth; Hasan, Tayyaba

    2016-04-01

    Nanoscale drug delivery vehicles can facilitate multimodal therapies of cancer by promoting tumour-selective drug release. However, few are effective because cancer cells develop ways to resist and evade treatment. Here, we introduce a photoactivable multi-inhibitor nanoliposome (PMIL) that imparts light-induced cytotoxicity in synchrony with a photoinitiated and sustained release of inhibitors that suppress tumour regrowth and treatment escape signalling pathways. The PMIL consists of a nanoliposome doped with a photoactivable chromophore (benzoporphyrin derivative, BPD) in the lipid bilayer, and a nanoparticle containing cabozantinib (XL184)—a multikinase inhibitor—encapsulated inside. Near-infrared tumour irradiation, following intravenous PMIL administration, triggers photodynamic damage of tumour cells and microvessels, and simultaneously initiates release of XL184 inside the tumour. A single PMIL treatment achieves prolonged tumour reduction in two mouse models and suppresses metastatic escape in an orthotopic pancreatic tumour model. The PMIL offers new prospects for cancer therapy by enabling spatiotemporal control of drug release while reducing systemic drug exposure and associated toxicities.

  15. A reverse signaling pathway downstream of Sema4A controls cell migration via Scrib

    PubMed Central

    Yang, Lida; Kaur, Harmandeep; Pestel, Jenny; Looso, Mario; Nolte, Hendrik; Krishnan, Ramesh K.; Bünemann, Moritz; Offermanns, Stefan; Swiercz, Jakub M.

    2017-01-01

    Semaphorins comprise a large family of ligands that regulate key cellular functions through their receptors, plexins. In this study, we show that the transmembrane semaphorin 4A (Sema4A) can also function as a receptor, rather than a ligand, and transduce signals triggered by the binding of Plexin-B1 through reverse signaling. Functionally, reverse Sema4A signaling regulates the migration of various cancer cells as well as dendritic cells. By combining mass spectrometry analysis with small interfering RNA screening, we identify the polarity protein Scrib as a downstream effector of Sema4A. We further show that binding of Plexin-B1 to Sema4A promotes the interaction of Sema4A with Scrib, thereby removing Scrib from its complex with the Rac/Cdc42 exchange factor βPIX and decreasing the activity of the small guanosine triphosphatase Rac1 and Cdc42. Our data unravel a role for Plexin-B1 as a ligand and Sema4A as a receptor and characterize a reverse signaling pathway downstream of Sema4A, which controls cell migration. PMID:28007914

  16. A reverse signaling pathway downstream of Sema4A controls cell migration via Scrib.

    PubMed

    Sun, Tianliang; Yang, Lida; Kaur, Harmandeep; Pestel, Jenny; Looso, Mario; Nolte, Hendrik; Krasel, Cornelius; Heil, Daniel; Krishnan, Ramesh K; Santoni, Marie-Josée; Borg, Jean-Paul; Bünemann, Moritz; Offermanns, Stefan; Swiercz, Jakub M; Worzfeld, Thomas

    2017-01-02

    Semaphorins comprise a large family of ligands that regulate key cellular functions through their receptors, plexins. In this study, we show that the transmembrane semaphorin 4A (Sema4A) can also function as a receptor, rather than a ligand, and transduce signals triggered by the binding of Plexin-B1 through reverse signaling. Functionally, reverse Sema4A signaling regulates the migration of various cancer cells as well as dendritic cells. By combining mass spectrometry analysis with small interfering RNA screening, we identify the polarity protein Scrib as a downstream effector of Sema4A. We further show that binding of Plexin-B1 to Sema4A promotes the interaction of Sema4A with Scrib, thereby removing Scrib from its complex with the Rac/Cdc42 exchange factor βPIX and decreasing the activity of the small guanosine triphosphatase Rac1 and Cdc42. Our data unravel a role for Plexin-B1 as a ligand and Sema4A as a receptor and characterize a reverse signaling pathway downstream of Sema4A, which controls cell migration. © 2017 Sun et al.

  17. A photoactivable multi-inhibitor nanoliposome for tumour control and simultaneous inhibition of treatment escape pathways.

    PubMed

    Spring, Bryan Q; Bryan Sears, R; Zheng, Lei Zak; Mai, Zhiming; Watanabe, Reika; Sherwood, Margaret E; Schoenfeld, David A; Pogue, Brian W; Pereira, Stephen P; Villa, Elizabeth; Hasan, Tayyaba

    2016-04-01

    Nanoscale drug delivery vehicles can facilitate multimodal therapies of cancer by promoting tumour-selective drug release. However, few are effective because cancer cells develop ways to resist and evade treatment. Here, we introduce a photoactivable multi-inhibitor nanoliposome (PMIL) that imparts light-induced cytotoxicity in synchrony with a photoinitiated and sustained release of inhibitors that suppress tumour regrowth and treatment escape signalling pathways. The PMIL consists of a nanoliposome doped with a photoactivable chromophore (benzoporphyrin derivative, BPD) in the lipid bilayer, and a nanoparticle containing cabozantinib (XL184)--a multikinase inhibitor--encapsulated inside. Near-infrared tumour irradiation, following intravenous PMIL administration, triggers photodynamic damage of tumour cells and microvessels, and simultaneously initiates release of XL184 inside the tumour. A single PMIL treatment achieves prolonged tumour reduction in two mouse models and suppresses metastatic escape in an orthotopic pancreatic tumour model. The PMIL offers new prospects for cancer therapy by enabling spatiotemporal control of drug release while reducing systemic drug exposure and associated toxicities.

  18. Modelization and experimental studies on the control of the glycolytic-glycogenolytic pathway in rat liver.

    PubMed

    Torres, N V

    1994-03-30

    In this paper we construct a model of the glycolytic-glycogenolytic converging pathway in rat liver, by integrating experimental data obtained in an in vitro system and information available from the literature. The model takes the mathematical expression of an S-system representation within the power law formalism (Savageau, 1976. Biochemical System Analysis: A study of function and design in Molecular Biology. Addison-Wesley, Reading, Mass.). By using this theoretical framework a model analysis was carried out that allowed us a) the assessment of the quality of the model in terms of its consistency and robustness, b) the steady state analysis and control characterization of the system, and c) the study of the dynamics of the system after changes in the level of two magnitudes of biological significance: the glucose concentration and the phosphofructokinase enzyme activity. Model predictions are compared with experimental measurements referred to Logarithmic Gains through fluxes and substrates concentrations showing that there is a good correlation between the model predictions and the experimentally determined values.

  19. Control of metabolic and cardiovascular function by the leptin-brain melanocortin pathway.

    PubMed

    do Carmo, Jussara M; da Silva, Alexandre A; Dubinion, John; Sessums, Price O; Ebaady, Sabira H; Wang, Zhen; Hall, John E

    2013-08-01

    Obesity is recognized as a major worldwide health problem. Excess weight gain is the most common cause of elevated blood pressure (BP) and markedly increases the risk of metabolic, cardiovascular and renal diseases. Although the mechanisms linking obesity with hypertension have not been fully elucidated, increased sympathetic nervous system (SNS) activity contributes to elevated BP in obese subjects. Recent evidence indicates that leptin and the central nervous system (CNS) melanocortin system, including melanocortin 4 receptors (MC4R), play a key role in linking obesity with increased SNS activity and hypertension. Leptin, a peptide-hormone produced by adipose tissue, crosses the blood-brain barrier and activates brain centers that control multiple metabolic functions as well as SNS activity and BP via the CNS melanocortin system. The crosstalk between peripheral signals (e.g., leptin) and activation of CNS pathways (e.g., MC4R) that regulate energy balance, SNS activity and BP represents an important target for treating obesity and its metabolic and cardiovascular consequences. © 2013 International Union of Biochemistry and Molecular Biology.

  20. Expression of hsp90 mediates cytoprotective effects in the gastrodermis of planarians.

    PubMed

    Conte, Maria; Isolani, Maria Emilia; Deri, Paolo; Mannini, Linda; Batistoni, Renata

    2011-01-01

    Heat shock proteins (HSPs) play a crucial role in the protection of cells. In the present study, we have identified an hsp90-related gene (Djhsp90) encoding a cytosolic form of HSP90 that is primarily expressed in gastrodermis of the planarian Dugesia japonica. Djhsp90 becomes significantly induced after traumatic amputation or other stress stimuli, such as exposure to X-ray or ultraviolet radiations, heat shock, or prolonged starvation. When Djhsp90 is silenced by ribonucleic acid interference (RNAi), planarians dramatically decrease in size, becoming unable to eat, and die in a few weeks. Our results indicate that this gene plays an essential cytoprotective role in the gastrodermis of planarians and suggest that this chaperone can be involved in autophagic processes that are activated by this tissue.

  1. Inhibition of the Mitochondrial Permeability Transition for Cytoprotection: Direct versus Indirect Mechanisms

    PubMed Central

    Martel, Cécile; Huynh, Le Ha; Garnier, Anne; Ventura-Clapier, Renée; Brenner, Catherine

    2012-01-01

    Mitochondria are fascinating organelles, which fulfill multiple cellular functions, as diverse as energy production, fatty acid β oxidation, reactive oxygen species (ROS) production and detoxification, and cell death regulation. The coordination of these functions relies on autonomous mitochondrial processes as well as on sustained cross-talk with other organelles and/or the cytosol. Therefore, this implies a tight regulation of mitochondrial functions to ensure cell homeostasis. In many diseases (e.g., cancer, cardiopathies, nonalcoholic fatty liver diseases, and neurodegenerative diseases), mitochondria can receive harmful signals, dysfunction and then, participate to pathogenesis. They can undergo either a decrease of their bioenergetic function or a process called mitochondrial permeability transition (MPT) that can coordinate cell death execution. Many studies present evidence that protection of mitochondria limits disease progression and severity. Here, we will review recent strategies to preserve mitochondrial functions via direct or indirect mechanisms of MPT inhibition. Thus, several mitochondrial proteins may be considered for cytoprotective-targeted therapies. PMID:22675634

  2. Health and Cellular Impacts of Air Pollutants: From Cytoprotection to Cytotoxicity

    PubMed Central

    Andreau, Karine; Leroux, Melanie; Bouharrour, Aida

    2012-01-01

    Air pollution as one of the ravages of our modern societies is primarily linked to urban centers, industrial activities, or road traffic. These atmospheric pollutants have been incriminated in deleterious health effects by numerous epidemiological and in vitro studies. Environmental air pollutants are a heterogeneous mixture of particles suspended into a liquid and gaseous phase which trigger the disruption of redox homeostasis—known under the term of cellular oxidative stress—in relation with the establishment of inflammation and cell death via necrosis, apoptosis, or autophagy. Activation or repression of the apoptotic process as an adaptative response to xenobiotics might lead to either acute or chronic toxicity. The purpose of this paper is to highlight the central role of oxidative stress induced by air pollutants and to focus on the subsequent cellular impacts ranging from cytoprotection to cytotoxicity by decreasing or stimulating apoptosis, respectively. PMID:22550588

  3. The unusual amino acid l-ergothioneine is a physiologic cytoprotectant

    PubMed Central

    Paul, BD; Snyder, SH

    2010-01-01

    Ergothioneine (ET) is an unusual sulfur-containing derivative of the amino acid, histidine, which is derived exclusively through the diet. Although ET was isolated a century ago, its physiologic function has not been clearly established. Recently, a highly specific transporter for ET (ETT) was identified in mammalian tissues, which explains abundant tissue levels of ET and implies a physiologic role. Using RNA interference, we depleted cells of its transporter. Cells lacking ETT are more susceptible to oxidative stress, resulting in increased mitochondrial DNA damage, protein oxidation and lipid peroxidation. ETT is concentrated in mitochondria, suggesting a specific role in protecting mitochondrial components such as DNA from oxidative damage associated with mitochondrial generation of superoxide. In combating cytotoxic effects of pyrogallol, a known superoxide generator, ET is as potent as glutathione. Because of its dietary origin and the toxicity associated with its depletion, ET may represent a new vitamin whose physiologic roles include antioxidant cytoprotection. PMID:19911007

  4. Solventless extraction methods for immature fruits: Evaluation of their antioxidant and cytoprotective activities.

    PubMed

    Heng, Ming Yuan; Katayama, Shigeru; Mitani, Takakazu; Ong, Eng Shi; Nakamura, Soichiro

    2017-04-15

    In this study, extraction of immature fruits using an environmentally friendly pressurized hot water extraction (PHWE) method was compared with the traditional reflux method. Extracts were tested for their polyphenol content using the Folin-Ciocalteu assay and for their antioxidant activity using the oxygen radical absorbance capacity (ORAC) assay. The highest amount of polyphenol was extracted from grape (stem) using PHWE at 100°C, or reflux extraction. This was followed by reflux extraction of grape (fruit). The results were similar for the ORAC assay. All samples extracted using PHWE at 100°C showed cytoprotective activity against H2O2-induced oxidative stress in Crandell-Reese feline kidney (CRFK) cells. This study demonstrated that beneficial compounds can be extracted from immature fruits without the use of organic solvents. The utilization of beneficial compounds present in immature fruits can also contribute to the reduction in agriculture waste generated.

  5. An antioxidant nanozyme that uncovers the cytoprotective potential of vanadia nanowires

    NASA Astrophysics Data System (ADS)

    Vernekar, Amit A.; Sinha, Devanjan; Srivastava, Shubhi; Paramasivam, Prasath U.; D'Silva, Patrick; Mugesh, Govindasamy

    2014-11-01

    Nanomaterials with enzyme-like properties has attracted significant interest, although limited information is available on their biological activities in cells. Here we show that V2O5 nanowires (Vn) functionally mimic the antioxidant enzyme glutathione peroxidase by using cellular glutathione. Although bulk V2O5 is known to be toxic to the cells, the property is altered when converted into a nanomaterial form. The Vn nanozymes readily internalize into mammalian cells of multiple origin (kidney, neuronal, prostate, cervical) and exhibit robust enzyme-like activity by scavenging the reactive oxygen species when challenged against intrinsic and extrinsic oxidative stress. The Vn nanozymes fully restore the redox balance without perturbing the cellular antioxidant defense, thus providing an important cytoprotection for biomolecules against harmful oxidative damage. Based on our findings, we envision that biocompatible Vn nanowires can provide future therapeutic potential to prevent ageing, cardiac disorders and several neurological conditions, including Parkinson’s and Alzheimer’s disease.

  6. Cellular uptake and organ accumulation of amphipolar metallocorroles with cytoprotective and cytotoxic properties.

    PubMed

    Okun, Zoya; Kuperschmidt, Lana; Youdim, Moussa B H; Gross, Zeev

    2011-05-01

    We report here an investigation that focuses on the organ distribution of metal complexes that are chelated by the amphipolar corrole whose macrocycle is decorated by two sulphonic acid head groups, which are emerging potential therapeutics against cancer (the cytotoxic Ga chelate) and diseases that are characterized by excessive production of ROS and RNS (the cytoprotective Mn and Fe derivatives). We show that the intraperitoneally injected fluorescent gallium(III) derivative accumulates in tissues sections of the kidney, liver, lung, heart, and pancreas. It also reaches the brain blood vessels, but does not cross the blood brain barrier. These findings are of prime importance for future in vivo studies on disease models, as they point toward a large utility of this kind of corrole chelates for treating cancer, neurodegenerative diseases characterized by "leaking BBB", cardiovascular diseases and diabetes.

  7. Vascular relaxation induced by Eucommiae Ulmoides Oliv. and its compounds Oroxylin A and wogonin: implications on their cytoprotection action.

    PubMed

    Akinyi, Mary; Gao, Xiu Mei; Li, Yu Hong; Wang, Bing Yao; Liu, Er Wei; Chai, Li Juan; JawoBah, Abdulai; Fan, Guan Wei

    2014-01-01

    The vascular relaxation action of Eucommiae Ulmoides Oliv. also known as Duzhong has been seen on arteries of the heart such as the aorta and the coronary artery which are elastic in nature. Duzhong is historically an active ingredient commonly used in hypertensive herbal prescriptions in China. This work investigated the vasodilating effect of Duzhong and its compounds (wogonin 10 μM and oroxylin-A) in the isolated intact rat heart, perfused retrograde according the method of Langendorff and the cytoprotective effect in EA.hy926 cell lines Coronary perfusion pressure was monitored with a pressure transducer connected to a side-arm of the aortic perfusion cannula. Duzhong induced vasorelaxation in a dose dependent manner, on precontracting the vessels with endothelin-1, Duzhong 10 mg/ml, wogonin 10 μM and oroxylin-A 10 μM could significantly lower the perfusion pressure in reference to positive control SNP, Duzhong induced vasodilation was not inhibited by L-NAME (nitric oxide inhibitor), but was significantly inhibited by Tetraethyl ammonium (TEA, a K(+) channel blocker and almost abolished by potassium chloride. The underlying mechanism was carried out in EA.hy926 cell lines. When these cells were treated with H2O2, there was higher expression of NOX-4, TNF-α and COX-2 mRNA. However, wogonin treatment attenuated the mRNA of NOX-4, TNF-α and COX-2. Wogonin also upregulated the mRNA expression of CAT, SOD-1 and GSR in oxidative stress induced by H2O2 EA.hy926 cells. Duzhong and compounds can exert an in vitro relaxation effect of the coronary artery and improve the heart function in Langendorff apparatus. This action appears to be endothelium dependent but not NO mediated. Cell culture findings indicated that wogonin can exert vascular and cellular protection by scavenging Reactive Oxygen Species.

  8. Vascular relaxation induced by Eucommiae Ulmoides Oliv. and its compounds Oroxylin A and wogonin: implications on their cytoprotection action

    PubMed Central

    Akinyi, Mary; Gao, Xiu Mei; Li, Yu Hong; Wang, Bing Yao; Liu, Er Wei; Chai, Li Juan; JawoBah, Abdulai; Fan, Guan Wei

    2014-01-01

    The vascular relaxation action of Eucommiae Ulmoides Oliv. also known as Duzhong has been seen on arteries of the heart such as the aorta and the coronary artery which are elastic in nature. Duzhong is historically an active ingredient commonly used in hypertensive herbal prescriptions in China. This work investigated the vasodilating effect of Duzhong and its compounds (wogonin 10 μM and oroxylin-A) in the isolated intact rat heart, perfused retrograde according the method of Langendorff and the cytoprotective effect in EA.hy926 cell lines Coronary perfusion pressure was monitored with a pressure transducer connected to a side-arm of the aortic perfusion cannula. Duzhong induced vasorelaxation in a dose dependent manner, on precontracting the vessels with endothelin-1, Duzhong 10 mg/ml, wogonin 10 μM and oroxylin-A 10 μM could significantly lower the perfusion pressure in reference to positive control SNP, Duzhong induced vasodilation was not inhibited by L-NAME (nitric oxide inhibitor), but was significantly inhibited by Tetraethyl ammonium (TEA, a K+ channel blocker and almost abolished by potassium chloride. The underlying mechanism was carried out in EA.hy926 cell lines. When these cells were treated with H2O2, there was higher expression of NOX-4, TNF-α and COX-2 mRNA. However, wogonin treatment attenuated the mRNA of NOX-4, TNF-α and COX-2. Wogonin also upregulated the mRNA expression of CAT, SOD-1 and GSR in oxidative stress induced by H2O2 EA.hy926 cells. Duzhong and compounds can exert an in vitro relaxation effect of the coronary artery and improve the heart function in Langendorff apparatus. This action appears to be endothelium dependent but not NO mediated. Cell culture findings indicated that wogonin can exert vascular and cellular protection by scavenging Reactive Oxygen Species. PMID:25419347

  9. Cytoprotective effects of calbindin-D(28k) against antimycin-A induced hypoxic injury in proximal tubular cells.

    PubMed

    Wu, Ming-Ju; Lai, Li-Wen; Lien, Yeong-Hau H

    2002-06-21

    Intracellular calcium plays an important role on the pathogenesis of hypoxia-induced cellular injury. Calbindin-D(28k), a cytosolic vitamin D-dependent calcium binding protein, can serve as a buffer to limit a surge in intracellular Ca2+ concentration ([Ca2+]i) induced by various stimulations. To evaluate the possible cytoprotective effect of calbindin-D(28k) against hypoxic injury in proximal tubular cells, a plasmid containing calbindin-D(28k) cDNA under the control of CMV immediate-early gene promoter was transfected into the murine proximal tubular epithelial (MCT) cells. The expression of calbindin-D(28k) in the transfected cells was verified with Northern blot analysis, Western blot analysis, and immunofluorescent staining. The non-transfected and transfected MCT cells were subjected to chemical hypoxia induced by antimycin A (10 microM) and glucose deprivation for 30-120 min. The transfection of calbindin-D(28k) reduced lactate dehydrogenase (LDH) release by 41%, 41%, 24%, and 24%, respectively, at 30, 60, 90 and 120 min after hypoxia when compared to the non-transfected cells (all p < 0.05). Cell viability after hypoxic injury was also significantly higher in transfected cells than non-transfected cells. Transfection with the plasmid without calbindin-D(28k) cDNA did not affect LDH release or cell viability after chemical hypoxic injury. [Ca+2]i was measured ratiometrically with fura-2 after exposure to chemical hypoxia. The rate of initial rise in [Ca2+]i and final [Ca+2]i at 30-120 min were significantly lowered in transfected cells. In conclusion, this study demonstrated that transfection of calbindin-D(28k) gene into MCT cells provide protective effects against chemical hypoxic injury probably through its buffering effects on [Ca+2]i.

  10. Biopsychosocial pathways linking subjective socioeconomic disadvantage to glycemic control in youths with type I diabetes.

    PubMed

    Zilioli, Samuele; Ellis, Deborah A; Carré, Justin M; Slatcher, Richard B

    2017-04-01

    Older adolescent and young adults (OAYA) with type 1 diabetes (T1D) living in contexts of socio-economic disadvantage (SED) suffer disproportionately from poor glycemic control and related health complications. Although SED may convey a variety of risks, it may exacerbate diabetes-related stress levels, which in turn may account for observed disparities in health outcomes. The primary goal of the present study was to investigate the relationship between subjective SED, diabetes-related perceived stress, and diurnal cortisol secretion in urban OAYA with T1D. A secondary goal was to determine if cortisol was related to measures of blood glucose (HbA1c and mean blood glucose). Analyses were conducted among OAYA ages 17-20 years (n=61) affected by T1D, who provided daily saliva samples for four days, measures of glycemic control (i.e., HbA1c and mean blood glucose assessed via Continuous Glucose Monitor), and completed psychosocial questionnaires. We found that subjective SED was associated with a flatter diurnal cortisol rhythm via diabetes-related stress. Flattened cortisol rhythm was, in turn, associated with higher levels of HbA1c, but not with mean blood glucose assessed via Continuous Glucose Monitor. These results represent some of the first empirical evidence on how distal social factors (i.e., subjective SED) and proximal psychological processes (diabetes-related perceived stress) are connected to condition-relevant biological mechanisms (i.e., elevated HbA1c), via broad biological pathways implicated in health (i.e., flatter cortisol slope).

  11. Growth control: re-examining Zyxin's role in the hippo pathway.

    PubMed

    Harvey, Kieran F

    2015-03-16

    The Hippo pathway is a conserved regulator of organ growth that computes information from the cellular microenvironment. A new study examines the role of the Hippo pathway protein Zyxin and finds that it antagonises Expanded to modulate F-actin and organ size. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Cytoprotective Effects of Pumpkin (Cucurbita Moschata) Fruit Extract against Oxidative Stress and Carbonyl Stress.

    PubMed

    Shayesteh, Reyhaneh; Kamalinejad, Mohammad; Adiban, Hasan; Kardan, Azin; Keyhanfar, Fariborz; Eskandari, Mohammad Reza

    2017-10-01

    Background Diabetes mellitus is a chronic endocrine disorder that is associated with significant mortality and morbidity due to microvascular and macrovascular complications. Diabetes complications accompanied with oxidative stress and carbonyl stress in different organs of human body because of the increased generation of free radicals and impaired antioxidant defense systems. In the meantime, reactive oxygen species (ROS) and reactive carbonyl species (RCS) have key mediatory roles in the development and progression of diabetes complications. Therapeutic strategies have recently focused on preventing such diabetes-related abnormalities using different natural and chemical compounds. Pumpkin (Cucurbita moschata) is one of the most important vegetables in the world with a broad-range of pharmacological activities such as antihyperglycemic effect. Methods In the present study, the cytoprotective effects of aqueous extract of C. moschata fruit on hepatocyte cytotoxicity induced by cumene hydroperoxide (oxidative stress model) or glyoxal (carbonylation model) were investigated using freshly isolated rat hepatocytes. Results The extract of C. moschata (50 μg/ml) excellently prevented oxidative and carbonyl stress markers, including hepatocyte lysis, ROS production, lipid peroxidation, glutathione depletion, mitochondrial membrane potential collapse, lysosomal damage, and cellular proteolysis. In addition, protein carbonylation was prevented by C. moschata in glyoxal-induced carbonyl stress. Conclusion It can be concluded that C. moschata has cytoprotective effects in oxidative stress and carbonyl stress models and this valuable vegetable can be considered as a suitable herbal product for the prevention of toxic subsequent of oxidative stress and carbonyl stress seen in chronic hyperglycemia. © Georg Thieme Verlag KG Stuttgart · New York.

  13. Cytoprotective and antioxidant effects of phenolic compounds from Haberlea rhodopensis Friv. (Gesneriaceae)

    PubMed Central

    Kondeva-Burdina, Magdalena; Zheleva-Dimitrova, Dimitrina; Nedialkov, Paraskev; Girreser, Ulrich; Mitcheva, Mitka

    2013-01-01

    Background: Haberlea rhodopensis Friv. (Gesneriaceae) is a rare poikilohydric endemic and preglacial relict growing in Balkan Peninsula. Previous investigations demonstrated strong antioxidant, antimicrobial and antimutagenic potential of alcoholic extract from the plant. Objective: The isolation of known caffeoyl phenylethanoid glucoside – myconoside and flavone-C-glycosides hispidulin 8-C-(2-O-syringoyl-β-glucopyranoside), hispidulin 8-C-(6-O-acetyl-2-O-syringoyl-β-glucopyranoside), and hispidulin 8-C-(6-O-acetyl-β-glucopyranoside) from the leaves of H. rhodopensis was carried out. The aim of this study was to investigate cyto-protective and antioxidant effects of isolated compounds. Materials and Methods: Antioxidant activity of isolated substances was examined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radicals; ferric reducing antioxidant power (FRAP) assay and inhibition of lipid peroxidation (LPO) in linoleic acid system by ferric thyocianate method. The compounds were investigated for their possible protective and antioxidant effects against tert-butyl hydroperoxide-induced oxidative stress in isolated rat hepatocytes. The levels of thiobarbituric acid reactive substances were assayed as an index of LPO. Lactate dehydrogenase leakage, cell viability, and reduced glutathione depletion were used as signs of cytotoxicity. Results: Myconoside demonstrated the highest DPPH radical scavenging, ABTS, FRAP, and antioxidant activity in linoleic acid system as well as the highest and statistically most significant protection and antioxidant activity against the toxic agent. Conclusion: Phenolic compounds isolated from H. rhodopensis demonstrated significant cytoprotective, radical scavenging potential, and inhibit lipid peroxidation, moreover, myconoside was found to be a new powerful natural antioxidant. PMID:24124280

  14. Mitochondria-specific transgenic overexpression of connexin-43 simulates preconditioning-induced cytoprotection of stem cells

    PubMed Central

    Lu, Gang; Haider, Husnain Kh; Porollo, Aleksey; Ashraf, Muhammad

    2010-01-01

    Aims We previously reported that preconditioning of stem cells with insulin-like growth factor-1 (IGF-1) translocated connexin-43 (Cx-43) into mitochondria, causing cytoprotection. We posit that these preconditioning effects could be simulated by mitochondria-specific overexpression of Cx-43. Methods and results During IGF-1-induced preconditioning of C57black/6 mouse bone marrow stem cell antigen-1+ (Sca-1+) cells, Cx-43 was mainly translocated onto the mitochondrial inner membrane, which was abrogated by an extracellular signal-regulated kinases 1 and 2 (ERK1/2) blocker PD98059. To investigate the role of mitochondrial Cx-43, we successfully designed a vector coding for full-length mouse Cx-43 with a mitochondria-targeting sequence (mito-Cx-43) and cloned into a shuttle vector (pShuttle-IRES-hrGFP-1) for mitochondria-specific overexpression of Cx-43 (mito-Cx-43). Sca-1+ cells with mito-Cx-43 reduced cytosolic accumulation of cytochrome c, lowered caspase-3 activity, and improved survival during index oxygen–glucose deprivation as determined by terminal deoxynucleotidyl transferase dUTP nick-end labelling and lactate dehydrogenase assays. Computational analysis revealed a B-cell lymphoma-2 (Bcl-2) homology domain-3 (BH3) motif in Cx-43 with a conserved pattern of amino acids consistent with the Bcl-2 family that regulated cytochrome c release. Moreover, computational secondary structure prediction indicated an extended α-helix in this region, a known condition for BH3-driven protein–protein interactions. Conclusion Cx-43 translocation into mitochondria during preconditioning was ERK1/2-dependent. Expression of mito-Cx-43 simulated the cytoprotective effects of preconditioning in stem cells. Structural features of Cx-43 were shared with the Bcl-2 family as determined by computational analysis. PMID:20833648

  15. Characterization of cytoprotective and toxic properties of iron chelator SIH, prochelator BSIH and their degradation products

    PubMed Central

    Jansová, Hana; Bureš, Jan; Macháček, Miloslav; Hašková, Pavlína; Jirkovská, Anna; Roh, Jaroslav; Wang, Qin; Franz, Katherine J.; Kovaříková, Petra; Šimůnek, Tomáš

    2016-01-01

    Free cellular iron catalyzes the formation of toxic hydroxyl radicals and therefore chelation of iron could be a promising therapeutic approach in pathological states associated with oxidative stress. Salicylaldehyde isonicotinoyl hydrazone (SIH) is a strong intracellular iron chelator with well documented potential to protect against oxidative damage both in vitro and in vivo. Due to the short biological half-life of SIH and risk of toxicity due to iron depletion, boronate prochelator BSIH has been designed. BSIH cannot bind iron until it is activated by certain reactive oxygen species to active chelator SIH. The aim of this study was to examine the toxicity and cytoprotective potential of BSIH, SIH, and their decomposition products against hydrogen peroxide-induced injury of H9c2 cardiomyoblast cells. Using HPLC, we observed that salicylaldehyde was the main decomposition products of SIH and BSIH, although a small amount of salicylic acid was also detected. In the case of BSIH, the concentration of formed salicylaldehyde consistently exceeded that of SIH. Isoniazid and salicylic acid were not toxic nor did they provide any antioxidant protective effect in H9c2 cells. In contrast, salicylaldehyde was able to chelate intracellular iron and significantly preserve cellular viability and mitochondrial inner membrane potential induced by hydrogen peroxide. However it was consistently less effective than SIH. The inherent toxicities of salicylaldehyde and SIH were similar. Hence, although SIH - the active chelating agent formed following the BSIH activation - undergoes rapid hydrolysis, its principal decomposition product salicylaldehyde accounts markedly for both cytoprotective and toxic properties. PMID:27046792

  16. Cytoprotective and antioxidant effects of phenolic compounds from Haberlea rhodopensis Friv. (Gesneriaceae).

    PubMed

    Kondeva-Burdina, Magdalena; Zheleva-Dimitrova, Dimitrina; Nedialkov, Paraskev; Girreser, Ulrich; Mitcheva, Mitka

    2013-10-01

    Haberlea rhodopensis Friv. (Gesneriaceae) is a rare poikilohydric endemic and preglacial relict growing in Balkan Peninsula. Previous investigations demonstrated strong antioxidant, antimicrobial and antimutagenic potential of alcoholic extract from the plant. The isolation of known caffeoyl phenylethanoid glucoside - myconoside and flavone-C-glycosides hispidulin 8-C-(2-O-syringoyl-β-glucopyranoside), hispidulin 8-C-(6-O-acetyl-2-O-syringoyl-β-glucopyranoside), and hispidulin 8-C-(6-O-acetyl-β-glucopyranoside) from the leaves of H. rhodopensis was carried out. The aim of this study was to investigate cyto-protective and antioxidant effects of isolated compounds. Antioxidant activity of isolated substances was examined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radicals; ferric reducing antioxidant power (FRAP) assay and inhibition of lipid peroxidation (LPO) in linoleic acid system by ferric thyocianate method. The compounds were investigated for their possible protective and antioxidant effects against tert-butyl hydroperoxide-induced oxidative stress in isolated rat hepatocytes. The levels of thiobarbituric acid reactive substances were assayed as an index of LPO. Lactate dehydrogenase leakage, cell viability, and reduced glutathione depletion were used as signs of cytotoxicity. Myconoside demonstrated the highest DPPH radical scavenging, ABTS, FRAP, and antioxidant activity in linoleic acid system as well as the highest and statistically most significant protection and antioxidant activity against the toxic agent. Phenolic compounds isolated from H. rhodopensis demonstrated significant cytoprotective, radical scavenging potential, and inhibit lipid peroxidation, moreover, myconoside was found to be a new powerful natural antioxidant.

  17. Characterization of cytoprotective and toxic properties of iron chelator SIH, prochelator BSIH and their degradation products.

    PubMed

    Jansová, Hana; Bureš, Jan; Macháček, Miloslav; Hašková, Pavlína; Jirkovská, Anna; Roh, Jaroslav; Wang, Qin; Franz, Katherine J; Kovaříková, Petra; Šimůnek, Tomáš

    2016-03-28

    Free cellular iron catalyzes the formation of toxic hydroxyl radicals and therefore chelation of iron could be a promising therapeutic approach in pathological states associated with oxidative stress. Salicylaldehyde isonicotinoyl hydrazone (SIH) is a strong intracellular iron chelator with well documented potential to protect against oxidative damage both in vitro and in vivo. Due to the short biological half-life of SIH and risk of toxicity due to iron depletion, boronate prochelator BSIH has been designed. BSIH cannot bind iron until it is activated by certain reactive oxygen species to active chelator SIH. The aim of this study was to examine the toxicity and cytoprotective potential of BSIH, SIH, and their decomposition products against hydrogen peroxide-induced injury of H9c2 cardiomyoblast cells. Using HPLC, we observed that salicylaldehyde was the main decomposition products of SIH and BSIH, although a small amount of salicylic acid was also detected. In the case of BSIH, the concentration of formed salicylaldehyde consistently exceeded that of SIH. Isoniazid and salicylic acid were not toxic nor did they provide any antioxidant protective effect in H9c2 cells. In contrast, salicylaldehyde was able to chelate intracellular iron and significantly preserve cellular viability and mitochondrial inner membrane potential induced by hydrogen peroxide. However it was consistently less effective than SIH. The inherent toxicities of salicylaldehyde and SIH were similar. Hence, although SIH - the active chelating agent formed following the BSIH activation - undergoes rapid hydrolysis, its principal decomposition product salicylaldehyde accounts markedly for both cytoprotective and toxic properties. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  18. Antioxidant and cytoprotective properties of D-tagatose in cultured murine hepatocytes.

    PubMed

    Paterna, J C; Boess, F; Stäubli, A; Boelsterli, U A

    1998-01-01

    D-Tagatose is a zero-energy producing ketohexose that is a powerful cytoprotective agent against chemically induced cell injury. To further explore the underlying mechanisms of cytoprotection, we investigated the effects of D-tagatose on both the generation of superoxide anion radicals and the consequences of oxidative stress driven by prooxidant compounds in intact cells. Primary cultures of hepatocytes derived from male C57BL/6 mice were exposed to the redox cycling drug nitrofurantoin (NFT). Lethal cell injury induced by 300 microM NFT was completely prevented by high concentrations (20 mM) of D-tagatose, whereas equimolar concentrations of glucose, mannitol, or xylose were ineffective. The extent of NFT-induced intracellular superoxide anion radical formation was not altered by D-tagatose, indicating that the ketohexose did not inhibit the reductive bioactivation of NFT. However, the NFT-induced decline of the intracellular GSH content was largely prevented by D-tagatose. The sugar also afforded complete protection against NFT toxicity in hepatocytes that had been chemically depleted of GSH. Furthermore, the ketohexose fully protected from increases in both membrane lipid peroxidation and protein carbonyl formation. In addition, D-tagatose completely prevented oxidative cell injury inflicted by toxic iron overload with ferric nitrilotriacetate (100 microM). In contrast, D-tagatose did not protect against lethal cell injury induced by tert-butyl hydroperoxide, a prooxidant which acts by hydroxyl radical-independent mechanisms and which is partitioned in the lipid bilayer. These results indicate that D-tagatose, which is a weak iron chelator, can antagonize the iron-dependent toxic consequences of intracellular oxidative stress in hepatocytes. The antioxidant properties of D-tagatose may result from sequestering the redox-active iron, thereby protecting more critical targets from the damaging potential of hydroxyl radical.

  19. Mitochondria-specific transgenic overexpression of connexin-43 simulates preconditioning-induced cytoprotection of stem cells.

    PubMed

    Lu, Gang; Haider, Husnain Kh; Porollo, Aleksey; Ashraf, Muhammad

    2010-11-01

    We previously reported that preconditioning of stem cells with insulin-like growth factor-1 (IGF-1) translocated connexin-43 (Cx-43) into mitochondria, causing cytoprotection. We posit that these preconditioning effects could be simulated by mitochondria-specific overexpression of Cx-43. During IGF-1-induced preconditioning of C57black/6 mouse bone marrow stem cell antigen-1(+) (Sca-1(+)) cells, Cx-43 was mainly translocated onto the mitochondrial inner membrane, which was abrogated by an extracellular signal-regulated kinases 1 and 2 (ERK1/2) blocker PD98059. To investigate the role of mitochondrial Cx-43, we successfully designed a vector coding for full-length mouse Cx-43 with a mitochondria-targeting sequence (mito-Cx-43) and cloned into a shuttle vector (pShuttle-IRES-hrGFP-1) for mitochondria-specific overexpression of Cx-43 (mito-Cx-43). Sca-1(+) cells with mito-Cx-43 reduced cytosolic accumulation of cytochrome c, lowered caspase-3 activity, and improved survival during index oxygen-glucose deprivation as determined by terminal deoxynucleotidyl transferase dUTP nick-end labelling and lactate dehydrogenase assays. Computational analysis revealed a B-cell lymphoma-2 (Bcl-2) homology domain-3 (BH3) motif in Cx-43 with a conserved pattern of amino acids consistent with the Bcl-2 family that regulated cytochrome c release. Moreover, computational secondary structure prediction indicated an extended α-helix in this region, a known condition for BH3-driven protein-protein interactions. Cx-43 translocation into mitochondria during preconditioning was ERK1/2-dependent. Expression of mito-Cx-43 simulated the cytoprotective effects of preconditioning in stem cells. Structural features of Cx-43 were shared with the Bcl-2 family as determined by computational analysis.

  20. Cytoprotection of kidney epithelial cells by compounds that target amino acid gated chloride channels.

    PubMed

    Venkatachalam, M A; Weinberg, J M; Patel, Y; Saikumar, P; Dong, Z

    1996-02-01

    Glycine, strychnine and certain chloride channel blockers were reported to protect cells against lethal cell injury. These effects have been attributed to interactions with membrane proteins related to CNS glycine gated chloride channel receptors. We have investigated the pharmacology of these actions. Madin-Darby canine kidney (MDCK) epithelial cells were depleted of adenosine triphosphate (ATP) by incubation in glucose free medium containing a mitochondrial uncoupler. Medium Ca2+ was adjusted to 100 nM in the presence of an ionophore such that intracellular Ca2+ did not increase, and Ca(2+)-related injury mechanisms were inhibited. This permitted more sensitive quantitation of protection against cell injury attributable to glycine or other agents whose actions might be related to those of the amino acid. Two classes of compounds showed cytoprotective activity in this system: (1) ligands at chloride channel receptors, such as glycine, strychnine and avermectin B1a; (2) chloride channel blockers, including cyanotriphenylboron and niflumic acid, both of which are known to bind to channel domains of CNS glycine receptors. Morphological and functional studies showed that the compounds preserved plasma membrane integrity, but permitted cell swelling. Substitution of medium chloride by gluconate, or chloride salts by sucrose, did not substantially modify lethal damage or its prevention by glycine or other drugs. The compounds did not modify ATP declines. At least for some compounds, cytoprotection appeared to be specific to structural features on the molecules. These observations are consistent with the hypothesis that a plasma membrane protein related to glycine-gated chloride channel receptors plays a significant role in cell injury, but indicate that the mechanisms of injury and protection by compounds active in this system are not related to chloride fluxes.

  1. Cytoprotective effect of lithium against spontaneous and induced apoptosis of lymphoid cell line MOLT-4.

    PubMed

    Pietruczuk, K; Jóźwik, A; Ruckemann-Dziurdzińska, K; Bryl, E; Witkowski, J M

    2009-01-01

    Lithium (Li) is still useful in the treatment of bipolar disorder. Cellular mechanisms of Li action are not fully understood and include some cytoprotective properties. Data concerning Li effect on the apoptotic mechanisms in cells other than neurons are fragmentary and contradictory. We have investigated anti-apoptotic activity of Li in a lymphoid derived MOLT-4 cell line. Spontaneous and camptothecin-induced apoptosis was analyzed in cells treated with 0-20 mM Li carbonate. Early apoptosis was identified as significant mitochondrial depolarization (JC-1 staining). Later stages of apoptosis were estimated with annexin V binding and by the proportion of cells containing sub-G1 amounts of DNA (PI staining). We have observed a biphasic effect of Li on the proportion of spontaneously apoptotic cells;namely, low (therapeutic) concentrations of Li had a significant effect stabilizing the mitochondrial membrane polarization, while 10 and 20mM Li increased apoptosis. The latter could be seen both as mitochondrial depolarization as well as an increased proportion of sub-G1 cells, accompanied by reduced proportion of S phase cells. Li at concentrations above 2 mM had a significant, dose-dependent, anti-apoptotic effect on the cells undergoing camptothecin induced apoptosis. In conclusion, demonstrated cytoprotective effect of Li is at least partially related to stabilization of mitochondrial membrane potential and to the reduction of DNA damaging effects in proliferating cells; both may form part of the mechanism through which Li is useful in therapy of bipolar disorder, but may have more general consequences.

  2. Antioxidant Gallic Acid-Functionalized Biodegradable in Situ Gelling Copolymers for Cytoprotective Antiglaucoma Drug Delivery Systems.

    PubMed

    Lai, Jui-Yang; Luo, Li-Jyuan

    2015-09-14

    In clinical ophthalmology, oxidative stress has been proposed as the initiating cause of ocular hypertension, which is one of the risk factors for glaucomatous damage and disease progression. In an attempt to improve the therapeutic efficacy of intracamerally administered pilocarpine, herein, a cytoprotective antiglaucoma drug delivery system composed of antioxidant gallic acid (GA)-functionalized gelatin-g-poly(N-isopropylacrylamide) (GN) biodegradable in situ gelling copolymer was developed for the first time. Analyses by UV-vis and Fourier transform infrared spectroscopies showed the formation of biopolymer-antioxidant covalent linkages in GNGA structures through a radical reaction in the presence of water-soluble redox initiators. The synthesized GNGA polymers with strong free radical scavenging effectiveness exhibited appropriate phase transition temperature and degradation rate as injectable bioerodible depots for minimally invasive pilocarpine delivery to the ocular anterior chamber. During the 2-week in vitro study, the sustained releases of sufficient amounts of pilocarpine for a therapeutic action in alleviating ocular hypertension could be achieved under physiological conditions. Results of cell viability, intracellular reactive oxygen species level, and intracellular calcium concentration indicated that the incorporation of antioxidant GA into GN structure can enhance cytoprotective effects of carrier materials against hydrogen peroxide-induced oxidative stress in lens epithelial cultures. Effective pharmacological responses (i.e., reduction of intraocular pressure and preservation of corneal endothelial cell morphology and density) in rabbits receiving intracameral GNGA injections containing pilocarpine were evidenced by clinical observations. The findings of in vivo studies also support the hypothesis that the GNGA carriers are more advantageous over their GN counterparts for the improvement of total antioxidant status in glaucomatous eyes with

  3. The CLE40 and CRN/CLV2 signaling pathways antagonistically control root meristem growth in Arabidopsis.

    PubMed

    Pallakies, Helge; Simon, Rüdiger

    2014-11-01

    Differentiation processes in the primary root meristem are controlled by several signaling pathways that are regulated by phytohormones or by secreted peptides. Long-term maintenance of an active root meristem requires that the generation of new stem cells and the loss of these from the meristem due to differentiation are precisely coordinated. Via phenotypic and large-scale transcriptome analyses of mutants, we show that the signaling peptide CLE40 and the receptor proteins CLV2 and CRN act in two genetically separable pathways that antagonistically regulate cell differentiation in the proximal root meristem. CLE40 inhibits cell differentiation throughout the primary root meristem by controlling genes with roles in abscisic acid, auxin, and cytokinin signaling. CRN and CLV2 jointly control target genes that promote cell differentiation specifically in the transition zone of the proximal root meristem. While CRN and CLV2 are not acting in the CLE40 signaling pathway under normal growth conditions, both proteins are required when the levels of CLE40 or related CLE peptides increase. We show here that two antagonistically acting pathways controlling root meristem differentiation can be activated by the same peptide in a dosage-dependent manner. © The Author 2014. Published by the Molecular Plant Shanghai Editorial Office in association with Oxford University Press on behalf of CSPB and IPPE, SIBS, CAS.

  4. Mitochondrial biotransformation of ω-(phenoxy)alkanoic acids, 3-(phenoxy)acrylic acids, and ω-(1-methyl-1H-imidazol-2-ylthio)alkanoic acids: A prodrug strategy for targeting cytoprotective antioxidants to mitochondria

    PubMed Central

    Roser, Kurt S.; Brookes, Paul S.; Wojtovich, Andrew P.; Olson, Leif P.; Shojaie, Jalil; Parton, Richard L.; Anders, M. W.

    2010-01-01

    Mitochondrial reactive oxygen species (ROS) generation and the attendant mitochondrial dysfunction are implicated in a range of disease states. The objective of the present studies was to test the hypothesis that the mitochondrial β-oxidation pathway could be exploited to deliver and biotransform the prodrugs ω-(phenoxy)alkanoic acids, 3-(phenoxy)acrylic acids, and ω-(1-methyl-1H-imidazol-2-ylthio)alkanoic acids to the corresponding phenolic antioxidants or methimazole. 3 -and 5-(Phenoxy)alkanoic acids and methyl-substituted analogs were biotransformed to phenols; rates of biotransformation decreased markedly with methyl-group substitution on the phenoxy moiety. 2,6-Dimethylphenol formation from the analogs 3-([2,6-dimethylphenoxy]methylthio)propanoic acid and 3-(2,6-dimethylphenoxy)acrylic acid was greater than that observed with ω-(2,6-dimethylphenoxy)alkanoic acids. 3- and 5-(1-Methyl-1H-imidazol-2-ylthio)alkanoic acids were rapidly biotransformed to the antioxidant methimazole and conferred significant cytoprotection against hypoxia-reoxygenation injury in isolated cardiomyocytes. Both 3-(2,6-dimethylphenoxy)propanoic acid and 3-(2,6-dimethylphenoxy)acrylic acid also afforded cytoprotection against hypoxia-reoxygenation injury in isolated cardiomyocytes. These results demonstrate that mitochondrial β-oxidation is a potentially useful delivery system for targeting antioxidants to mitochondria. PMID:20129794

  5. Adaptive Posttranslational Control in Cellular Stress Response Pathways and Its Relationship to Toxicity Testing and Safety Assessment.

    PubMed

    Zhang, Qiang; Bhattacharya, Sudin; Pi, Jingbo; Clewell, Rebecca A; Carmichael, Paul L; Andersen, Melvin E

    2015-10-01

    Although transcriptional induction of stress genes constitutes a major cellular defense program against a variety of stressors, posttranslational control directly regulating the activities of preexisting stress proteins provides a faster-acting alternative response. We propose that posttranslational control is a general adaptive mechanism operating in many stress pathways. Here with the aid of computational models, we first show that posttranslational control fulfills two roles: (1) handling small, transient stresses quickly and (2) stabilizing the negative feedback transcriptional network. We then review the posttranslational control pathways for major stress responses-oxidative stress, metal stress, hyperosmotic stress, DNA damage, heat shock, and hypoxia. Posttranslational regulation of stress protein activities occurs by reversible covalent modifications, allosteric or non-allosteric enzymatic regulations, and physically induced protein structural changes. Acting in feedback or feedforward networks, posttranslational control may establish a threshold level of cellular stress. Sub-threshold stresses are handled adequately by posttranslational control without invoking gene transcription. With supra-threshold stress levels, cellular homeostasis cannot be maintained and transcriptional induction of stress genes and other gene programs, eg, those regulating cell metabolism, proliferation, and apoptosis, takes place. The loss of homeostasis with consequent changes in cellular function may lead to adverse cellular outcomes. Overall, posttranslational and transcriptional control pathways constitute a stratified cellular defense system, handling stresses coherently across time and intensity. As cell-based assays become a focus for chemical testing anchored on toxicity pathways, examination of proteomic and metabolomic changes as a result of posttranslational control occurring in the absence of transcriptomic alterations deserves more attention. © The Author 2015

  6. Adaptive Posttranslational Control in Cellular Stress Response Pathways and Its Relationship to Toxicity Testing and Safety Assessment

    PubMed Central

    Zhang, Qiang; Bhattacharya, Sudin; Pi, Jingbo; Clewell, Rebecca A.; Carmichael, Paul L.; Andersen, Melvin E.

    2015-01-01

    Although transcriptional induction of stress genes constitutes a major cellular defense program against a variety of stressors, posttranslational control directly regulating the activities of preexisting stress proteins provides a faster-acting alternative response. We propose that posttranslational control is a general adaptive mechanism operating in many stress pathways. Here with the aid of computational models, we first show that posttranslational control fulfills two roles: (1) handling small, transient stresses quickly and (2) stabilizing the negative feedback transcriptional network. We then review the posttranslational control pathways for major stress responses—oxidative stress, metal stress, hyperosmotic stress, DNA damage, heat shock, and hypoxia. Posttranslational regulation of stress protein activities occurs by reversible covalent modifications, allosteric or non-allosteric enzymatic regulations, and physically induced protein structural changes. Acting in feedback or feedforward networks, posttranslational control may establish a threshold level of cellular stress. Sub-threshold stresses are handled adequately by posttranslational control without invoking gene transcription. With supra-threshold stress levels, cellular homeostasis cannot be maintained and transcriptional induction of stress genes and other gene programs, eg, those regulating cell metabolism, proliferation, and apoptosis, takes place. The loss of homeostasis with consequent changes in cellular function may lead to adverse cellular outcomes. Overall, posttranslational and transcriptional control pathways constitute a stratified cellular defense system, handling stresses coherently across time and intensity. As cell-based assays become a focus for chemical testing anchored on toxicity pathways, examination of proteomic and metabolomic changes as a result of posttranslational control occurring in the absence of transcriptomic alterations deserves more attention. PMID:26408567

  7. Controls on shallow landslide initiation: Diverse hydrologic pathways, 3D failure geometries, and unsaturated soil suctions

    NASA Astrophysics Data System (ADS)

    Reid, Mark; Iverson, Richard; Brien, Dianne; Iverson, Neal; LaHusen, Richard; Logan, Matthew

    2017-04-01

    Shallow landslides and ensuing debris flows are a common hazard worldwide, yet forecasting their initiation at a specific site is challenging. These challenges arise, in part, from diverse near-surface hydrologic pathways under different wetting conditions, 3D failure geometries, and the effects of suction in partially saturated soils. Simplistic hydrologic models typically used for regional hazard assessment disregard these complexities. As an alterative to field studies where the effects of these governing factors can be difficult to isolate, we used the USGS debris-flow flume to conduct controlled, field-scale landslide initiation experiments. Using overhead sprinklers or groundwater injectors on the flume bed, we triggered failures using three different wetting conditions: groundwater inflow from below, prolonged moderate-intensity precipitation, and bursts of high-intensity precipitation. Failures occurred in 6 m3 (0.65-m thick and 2-m wide) prisms of loamy sand on a 31° slope; these field-scale failures enabled realistic incorporation of nonlinear scale-dependent effects such as soil suction. During the experiments, we monitored soil deformation, variably saturated pore pressures, and moisture changes using ˜50 sensors sampling at 20 Hz. From ancillary laboratory tests, we determined shear strength, saturated hydraulic conductivities, and unsaturated moisture retention characteristics. The three different wetting conditions noted above led to different hydrologic pathways and influenced instrumental responses and failure timing. During groundwater injection, pore-water pressures increased from the bed of the flume upwards into the sediment, whereas prolonged moderate infiltration wet the sediment from the ground surface downward. In both cases, pore pressures acting on the impending failure surface slowly rose until abrupt failure. In contrast, a burst of intense sprinkling caused rapid failure without precursory development of widespread positive pore

  8. Combining metabolic and protein engineering of a terpenoid biosynthetic pathway for overproduction and selectivity control

    PubMed Central

    Leonard, Effendi; Ajikumar, Parayil Kumaran; Thayer, Kelly; Xiao, Wen-Hai; Mo, Jeffrey D.; Tidor, Bruce; Stephanopoulos, Gregory; Prather, Kristala L. J.

    2010-01-01

    A common strategy of metabolic engineering is to increase the endogenous supply of precursor metabolites to improve pathway productivity. The ability to further enhance heterologous production of a desired compound may be limited by the inherent capacity of the imported pathway to accommodate high precursor supply. Here, we present engineered diterpenoid biosynthesis as a case where insufficient downstream pathway capacity limits high-level levopimaradiene production in Escherichia coli. To increase levopimaradiene synthesis, we amplified the flux toward isopentenyl diphosphate and dimethylallyl diphosphate precursors and reprogrammed the rate-limiting downstream pathway by generating combinatorial mutations in geranylgeranyl diphosphate synthase and levopimaradiene synthase. The mutant library contained pathway variants that not only increased diterpenoid production but also tuned the selectivity toward levopimaradiene. The most productive pathway, combining precursor flux amplification and mutant synthases, conferred approximately 2,600-fold increase in levopimaradiene levels. A maximum titer of approximately 700 mg/L was subsequently obtained by cultivation in a bench-scale bioreactor. The present study highlights the importance of engineering proteins along with pathways as a key strategy in achieving microbial biosynthesis and overproduction of pharmaceutical and chemical products. PMID:20643967

  9. Redox potential as a master variable controlling pathways of metal reduction by Geobacter sulfurreducens.

    PubMed

    Levar, Caleb E; Hoffman, Colleen L; Dunshee, Aubrey J; Toner, Brandy M; Bond, Daniel R

    2017-03-01

    Geobacter sulfurreducens uses at least two different pathways to transport electrons out of the inner membrane quinone pool before reducing acceptors beyond the outer membrane. When growing on electrodes poised at oxidizing potentials, the CbcL-dependent pathway operates at or below redox potentials of -0.10 V vs the standard hydrogen electrode, whereas the ImcH-dependent pathway operates only above this value. Here, we provide evidence that G. sulfurreducens also requires different electron transfer proteins for reduction of a wide range of Fe(III)- and Mn(IV)-(oxyhydr)oxides, and must transition from a high- to low-potential pathway during reduction of commonly studied soluble and insoluble metal electron acceptors. Freshly precipitated Fe(III)-(oxyhydr)oxides could not be reduced by mutants lacking the high-potential pathway. Aging these minerals by autoclaving did not change their powder X-ray diffraction pattern, but restored reduction by mutants lacking the high-potential pathway. Mutants lacking the low-potential, CbcL-dependent pathway had higher growth yields with both soluble and insoluble Fe(III). Together, these data suggest that the ImcH-dependent pathway exists to harvest additional energy when conditions permit, and CbcL switches on to allow respiration closer to thermodynamic equilibrium conditions. With evidence of multiple pathways within a single organism, the study of extracellular respiration should consider not only the crystal structure or solubility of a mineral electron acceptor, but rather the redox potential, as this variable determines the energetic reward affecting reduction rates, extents, and final microbial growth yields in the environment.

  10. Redox potential as a master variable controlling pathways of metal reduction by Geobacter sulfurreducens

    PubMed Central

    Levar, Caleb E; Hoffman, Colleen L; Dunshee, Aubrey J; Toner, Brandy M; Bond, Daniel R

    2017-01-01

    Geobacter sulfurreducens uses at least two different pathways to transport electrons out of the inner membrane quinone pool before reducing acceptors beyond the outer membrane. When growing on electrodes poised at oxidizing potentials, the CbcL-dependent pathway operates at or below redox potentials of –0.10 V vs the standard hydrogen electrode, whereas the ImcH-dependent pathway operates only above this value. Here, we provide evidence that G. sulfurreducens also requires different electron transfer proteins for reduction of a wide range of Fe(III)- and Mn(IV)-(oxyhydr)oxides, and must transition from a high- to low-potential pathway during reduction of commonly studied soluble and insoluble metal electron acceptors. Freshly precipitated Fe(III)-(oxyhydr)oxides could not be reduced by mutants lacking the high-potential pathway. Aging these minerals by autoclaving did not change their powder X-ray diffraction pattern, but restored reduction by mutants lacking the high-potential pathway. Mutants lacking the low-potential, CbcL-dependent pathway had higher growth yields with both soluble and insoluble Fe(III). Together, these data suggest that the ImcH-dependent pathway exists to harvest additional energy when conditions permit, and CbcL switches on to allow respiration closer to thermodynamic equilibrium conditions. With evidence of multiple pathways within a single organism, the study of extracellular respiration should consider not only the crystal structure or solubility of a mineral electron acceptor, but rather the redox potential, as this variable determines the energetic reward affecting reduction rates, extents, and final microbial growth yields in the environment. PMID:28045456

  11. Hydrogen peroxide responsive miR153 targets Nrf2/ARE cytoprotection in paraquat induced dopaminergic neurotoxicity.

    PubMed

    Narasimhan, Madhusudhanan; Riar, Amanjot Kaur; Rathinam, Mary Latha; Vedpathak, Dhanashree; Henderson, George; Mahimainathan, Lenin

    2014-08-04

    Epidemiological and animal studies suggest that environmental toxins including paraquat (PQ) increase the risk of developing Parkinson's disease (PD) by damaging nigrostriatal dopaminergic neurons. We previously showed that overexpression of a group of microRNAs (miRs) affects the antioxidant promoting factor, Nrf2 and related glutathione-redox homeostasis in SH-SY5Y dopaminergic neurons. Although, dysregulation of redox balance by PQ is well documented, the role for miRs and their impact have not been elucidated. In the current study we investigated whether PQ impairs Nrf2 and its related cytoprotective machinery by misexpression of specific fine tune miRs in SH-SY5Y neurons. Real time PCR analysis revealed that PQ significantly (p<0.05) increased the expression of brain enriched miR153 with an associated decrease in Nrf2 and its function as revealed by decrease in 4× ARE activity and expression of GCLC and NQO1. Also, PQ and H2O2-induced decrease in Nrf2 3' UTR activity was restored on miR153 site mutation suggesting a 3' UTR interacting role. Overexpression of either anti-miR153 or Nrf2 cDNA devoid of 3' UTR prevented PQ and H2O2-induced loss in Nrf2 activity confirming that PQ could cause miR153 to bind to and target Nrf2 3' UTR thereby weakening the cellular antioxidant defense. Adenovirus mediated overexpression of cytoplasmic catalase (Ad cCAT) confirmed that PQ induced miR153 is hydrogen peroxide (H2O2) dependent. In addition, Ad cCAT significantly (p<0.05) negated the PQ induced dysregulation of Nrf2 and function along with minimizing ROS, caspase 3/7 activation and neuronal death. Altogether, these results suggest a critical role for oxidant mediated miR153-Nrf2/ARE pathway interaction in paraquat neurotoxicity. This novel finding facilitates the understanding of molecular mechanisms and to develop appropriate management alternatives to counteract PQ-induced neuronal pathogenesis. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  12. Hydrogen Peroxide responsive miR153 targets Nrf2/ARE cytoprotection in paraquat induced dopaminergic neurotoxicitya

    PubMed Central

    Narasimhan, Madhusudhanan; Riar, Amanjot Kaur; Rathinam, Mary Latha; Vedpathak, Dhanashree; Henderson, George; Mahimainathan, Lenin

    2014-01-01

    Epidemiological and animal studies suggest that environmental toxins including paraquat (PQ) increase the risk of developing Parkinson's disease (PD) by damaging nigrostriatal dopaminergic neurons. We previously showed that overexpression of a group of microRNAs (miRs) affects the antioxidant promoting factor, Nrf2 and related glutathione-redox homeostasis in SH-SY5Y dopaminergic neurons. Although, dysregulation of redox balance by PQ is well documented, the role for miRs and their impact have not been elucidated. In the current study we investigated whether PQ impairs Nrf2 and its related cytoprotective machinery by misexpression of specific fine tune miRs in SH-SY5Y neurons. Real time PCR analysis revealed that PQ significantly (p<0.05) increased the expression of brain enriched miR153 with an associated decrease in Nrf2 and its function as revealed by decrease in 4× ARE activity and expression of GCLC and NQO1. Also, PQ and H2O2-induced decrease in Nrf2 3′ UTR activity was restored on miR153 site mutation suggesting a 3′ UTR interacting role. Overexpression of either anti-miR153 or Nrf2 cDNA devoid of 3′ UTR prevented PQ and H2O2-induced loss in Nrf2 activity confirming that PQ could cause miR153 to bind to and target Nrf2 3′ UTR thereby weakening the cellular antioxidant defense. Adenovirus mediated overexpression of cytoplasmic catalase (Ad cCAT) confirmed that PQ induced miR153 is hydrogen peroxide (H2O2) dependent. In addition, Ad cCAT significantly (p<0.05) negated the PQ induced dysregulation of Nrf2 and function along with minimizing ROS, caspase 3/7 activation and neuronal death. Altogether, these results suggest a critical role for oxidant mediated miR153-Nrf2/ARE pathway interaction in paraquat neurotoxicity. This novel finding facilitates the understanding of molecular mechanisms and to develop appropriate management alternatives to counteract PQ-induced neuronal pathogenesis. PMID:24866057

  13. Oxidative stress modulates heme synthesis and induces peroxiredoxin-2 as a novel cytoprotective response in β-thalassemic erythropoiesis

    PubMed Central

    De Franceschi, Lucia; Bertoldi, Mariarita; De Falco, Luigia; Santos Franco, Sara; Ronzoni, Luisa; Turrini, Franco; Colancecco, Alessandra; Camaschella, Clara; Cappellini, Maria Domenica; Iolascon, Achille

    2011-01-01

    Background β-thalassemic syndromes are inherited red cell disorders characterized by severe ineffective erythropoiesis and increased levels of reactive oxygen species whose contribution to β-thalassemic anemia is only partially understood. Design and Methods We studied erythroid precursors from normal and β-thalassemic peripheral CD34+ cells in two-phase liquid culture by proteomic, reverse transcriptase polymerase chain reaction and immunoblot analyses. We measured intracellular reactive oxygen species, heme levels and the activity of δ-aminolevulinate-synthase-2. We exposed normal cells and K562 cells with silenced peroxiredoxin-2 to H2O2 and generated a recombinant peroxiredoxin-2 for kinetic measurements in the presence of H2O2 or hemin. Results In β-thalassemia the increased production of reactive oxygen species was associated with down-regulation of heme oxygenase-1 and biliverdin reductase and up-regulation of peroxiredoxin-2. In agreement with these observations in β-thalassemic cells we found decreased heme levels related to significantly reduced activity of the first enzyme of the heme pathway, δ-aminolevulinate synthase-2 without differences in its expression. We demonstrated that the activity of recombinant δ-aminolevulinate synthase-2 is inhibited by both reactive oxygen species and hemin as a protective mechanism in β-thalassemic cells. We then addressed the question of the protective role of peroxiredoxin-2 in erythropoiesis by exposing normal cells to oxidative stress and silencing peroxiredoxin-2 in human erythroleukemia K562 cells. We found that peroxiredoxin-2 expression is up-regulated in response to oxidative stress and required for K562 cells to survive oxidative stress. We then showed that peroxiredoxin-2 binds heme in erythroid precursors with high affinity, suggesting a possible multifunctional cytoprotective role of peroxiredoxin-2 in β-thalassemia. Conclusions In β-thalassemic erythroid cells the reduction of

  14. A proteolytic pathway that controls glucose uptake in fat and muscle

    PubMed Central

    Belman, Jonathan P.; Habtemichael, Estifanos N.; Bogan, Jonathan S.

    2013-01-01

    Insulin regulates glucose uptake by controlling the subcellular location of GLUT4 glucose transporters. GLUT4 is sequestered within fat and muscle cells during low-insulin states, and is translocated to the cell surface upon insulin stimulation. The TUG protein is a functional tether that sequesters GLUT4 at the Golgi matrix. To stimulate glucose uptake, insulin triggers TUG endoproteolytic cleavage. Cleavage accounts for a large proportion of the acute effect of insulin to mobilize GLUT4 to the cell surface. During ongoing insulin exposure, endocytosed GLUT4 recycles to the plasma membrane directly from endosomes, and bypasses a TUG-regulated trafficking step. Insulin acts through the TC10α GTPase and its effector protein, PIST, to stimulate TUG cleavage. This action is coordinated with insulin signals through AS160/Tbc1D4 and Tbc1D1 to modulate Rab GTPases, and with other signals to direct overall GLUT4 targeting. Data support the idea that the N-terminal TUG cleavage product, TUGUL, functions as a novel ubiquitin-like protein modifier to facilitate GLUT4 movement to the cell surface. The C-terminal TUG cleavage product is extracted from the Golgi matrix, which vacates an “anchoring” site to permit subsequent cycles of GLUT4 retention and release. Together, GLUT4 vesicle translocation and TUG cleavage may coordinate glucose uptake with physiologic effects of other proteins present in the GLUT4-containing vesicles, and with potential additional effects of the TUG C-terminal product. Understanding this TUG pathway for GLUT4 retention and release will shed light on the regulation of glucose uptake and the pathogenesis of type 2 diabetes. PMID:24114239

  15. The alternative complement pathway control protein H binds to immune complexes and serves their detection

    SciTech Connect

    Nydegger, U.E.; Corvetta, A.; Spaeth, P.J.; Spycher, M.

    1983-01-01

    During solubilization of immune complexes C3b becomes fixed to the immunoglobulin part and serves as a receptor for the alternative complement pathway control protein H. The H-C3b immune complex interaction can be made detectable using 4% polyethyleneglycol to separate free from bound /sup 125/I-H. Tetanus toxoid (Te)/anti-Te complexes kept soluble with fresh serum and containing 125 IU of specific antibody bound 18% of /sup 125/I-H; when fresh serum was chelated with 10 mM EDTA, /sup 125/I-H binding was only 5%. On sucrose density gradients, the H-binding material sedimented in the range of 12 to 30 S. In 36 serum samples from rheumatoid arthritis (RA) patients and in 12 serum samples from patients with systemic lupus erythematosus (SLE), /sup 125/I-H binding was significantly elevated to 9.5 +/- 4.7% (mean +/- 1 SD) and 13.3 +/- 5.6%, respectively, while /sup 125/I-H binding by 36 normal human sera was 4 +/- 2%. RA samples (17/36, 47%) and SLE samples (9/12, 75%) had H-binding values increased by more than 2 SD above the normal mean. The serum samples were also assessed for conglutinin- and C1q-binding activities; a significant correlation between H and C1q binding was observed (P less than 0.001); there was no correlation between H and conglutinin binding. Although binding to immune complexes through its interaction with C3b, H clearly detects a population of complexes other than conglutinin, thus expanding the possibilities of further characterizing pathological complexes.

  16. The control of axillary meristem fate in the maize ramosa pathway.

    PubMed

    Gallavotti, Andrea; Long, Jeff A; Stanfield, Sharon; Yang, Xiang; Jackson, David; Vollbrecht, Erik; Schmidt, Robert J

    2010-09-01

    Plant axillary meristems are composed of highly organized, self-renewing stem cells that produce indeterminate branches or terminate in differentiated structures, such as the flowers. These opposite fates, dictated by both genetic and environmental factors, determine interspecific differences in the architecture of plants. The Cys(2)-His(2) zinc-finger transcription factor RAMOSA1 (RA1) regulates the fate of most axillary meristems during the early development of maize inflorescences, the tassel and the ear, and has been implicated in the evolution of grass architecture. Mutations in RA1 or any other known members of the ramosa pathway, RAMOSA2 and RAMOSA3, generate highly branched inflorescences. Here, we report a genetic screen for the enhancement of maize inflorescence branching and the discovery of a new regulator of meristem fate: the RAMOSA1 ENHANCER LOCUS2 (REL2) gene. rel2 mutants dramatically increase the formation of long branches in ears of both ra1 and ra2 mutants. REL2 encodes a transcriptional co-repressor similar to the TOPLESS protein of Arabidopsis, which is known to maintain apical-basal polarity during embryogenesis. REL2 is capable of rescuing the embryonic defects of the Arabidopsis topless-1 mutant, suggesting that REL2 also functions as a transcriptional co-repressor throughout development. We show by genetic and molecular analyses that REL2 physically interacts with RA1, indicating that the REL2/RA1 transcriptional repressor complex antagonizes the formation of indeterminate branches during maize inflorescence development. Our results reveal a novel mechanism for the control of meristem fate and the architecture of plants.

  17. The control of axillary meristem fate in the maize ramosa pathway

    PubMed Central

    Gallavotti, Andrea; Long, Jeff A.; Stanfield, Sharon; Yang, Xiang; Jackson, David; Vollbrecht, Erik; Schmidt, Robert J.

    2010-01-01

    Plant axillary meristems are composed of highly organized, self-renewing stem cells that produce indeterminate branches or terminate in differentiated structures, such as the flowers. These opposite fates, dictated by both genetic and environmental factors, determine interspecific differences in the architecture of plants. The Cys2-His2 zinc-finger transcription factor RAMOSA1 (RA1) regulates the fate of most axillary meristems during the early development of maize inflorescences, the tassel and the ear, and has been implicated in the evolution of grass architecture. Mutations in RA1 or any other known members of the ramosa pathway, RAMOSA2 and RAMOSA3, generate highly branched inflorescences. Here, we report a genetic screen for the enhancement of maize inflorescence branching and the discovery of a new regulator of meristem fate: the RAMOSA1 ENHANCER LOCUS2 (REL2) gene. rel2 mutants dramatically increase the formation of long branches in ears of both ra1 and ra2 mutants. REL2 encodes a transcriptional co-repressor similar to the TOPLESS protein of Arabidopsis, which is known to maintain apical-basal polarity during embryogenesis. REL2 is capable of rescuing the embryonic defects of the Arabidopsis topless-1 mutant, suggesting that REL2 also functions as a transcriptional co-repressor throughout development. We show by genetic and molecular analyses that REL2 physically interacts with RA1, indicating that the REL2/RA1 transcriptional repressor complex antagonizes the formation of indeterminate branches during maize inflorescence development. Our results reveal a novel mechanism for the control of meristem fate and the architecture of plants. PMID:20699296

  18. Characterizing the roles of changing population size and selection on the evolution of flux control in metabolic pathways.

    PubMed

    Orlenko, Alena; Chi, Peter B; Liberles, David A

    2017-05-25

    Understanding the genotype-phenotype map is fundamental to our understanding of genomes. Genes do not function independently, but rather as part of networks or pathways. In the case of metabolic pathways, flux through the pathway is an important next layer of biological organization up from the individual gene or protein. Flux control in metabolic pathways, reflecting the importance of mutation to individual enzyme genes, may be evolutionarily variable due to the role of mutation-selection-drift balance. The evolutionary stability of rate limiting steps and the patterns of inter-molecular co-evolution were evaluated in a simulated pathway with a system out of equilibrium due to fluctuating selection, population size, or positive directional selection, to contrast with those under stabilizing selection. Depending upon the underlying population genetic regime, fluctuating population size was found to increase the evolutionary stability of rate limiting steps in some scenarios. This result was linked to patterns of local adaptation of the population. Further, during positive directional selection, as with more complex mutational scenarios, an increase in the observation of inter-molecular co-evolution was observed. Differences in patterns of evolution when systems are in and out of equilibrium, including during positive directional selection may lead to predictable differences in observed patterns for divergent evolutionary scenarios. In particular, this result might be harnessed to detect differences between compensatory processes and directional processes at the pathway level based upon evolutionary observations in individual proteins. Detecting functional shifts in pathways reflects an important milestone in predicting when changes in genotypes result in changes in phenotypes.

  19. Identification of Alternative Vapor Intrusion Pathways Using Controlled Pressure Testing, Soil Gas Monitoring, and Screening Model Calculations.

    PubMed

    Guo, Yuanming; Holton, Chase; Luo, Hong; Dahlen, Paul; Gorder, Kyle; Dettenmaier, Erik; Johnson, Paul C

    2015-11-17

    Vapor intrusion (VI) pathway assessment and data interpretation have been guided by an historical conceptual model in which vapors originating from contaminated soil or groundwater diffuse upward through soil and are swept into a building by soil gas flow induced by building underpressurization. Recent studies reveal that alternative VI pathways involving neighborhood sewers, land drains, and other major underground piping can also be significant VI contributors, even to buildings beyond the delineated footprint of soil and groundwater contamination. This work illustrates how controlled-pressure-method testing (CPM), soil gas sampling, and screening-level emissions calculations can be used to identify significant alternative VI pathways that might go undetected by conventional sampling under natural conditions at some sites. The combined utility of these tools is shown through data collected at a long-term study house, where a significant alternative VI pathway was discovered and altered so that it could be manipulated to be on or off. Data collected during periods of natural and CPM conditions show that the alternative pathway was significant, but its presence was not identifiable under natural conditions; it was identified under CPM conditions when measured emission rates were 2 orders of magnitude greater than screening-model estimates and subfoundation vertical soil gas profiles changed and were no longer consistent with the conventional VI conceptual model.

  20. Spatial landmarks regulate a Cdc42-dependent MAPK pathway to control differentiation and the response to positional compromise

    PubMed Central

    Basu, Sukanya; Vadaie, Nadia; Prabhakar, Aditi; Li, Boyang; Adhikari, Hema; Pitoniak, Andrew; Chow, Jacky; Chavel, Colin A.; Cullen, Paul J.

    2016-01-01

    A fundamental problem in cell biology is to understand how spatial information is recognized and integrated into morphogenetic responses. Budding yeast undergoes differentiation to filamentous growth, which involves changes in cell polarity through mechanisms that remain obscure. Here we define a regulatory input where spatial landmarks (bud-site–selection proteins) regulate the MAPK pathway that controls filamentous growth (fMAPK pathway). The bud-site GTPase Rsr1p regulated the fMAPK pathway through Cdc24p, the guanine nucleotide exchange factor for the polarity establishment GTPase Cdc42p. Positional landmarks that direct Rsr1p to bud sites conditionally regulated the fMAPK pathway, corresponding to their roles in regulating bud-site selection. Therefore, cell differentiation is achieved in part by the reorganization of polarity at bud sites. In line with this conclusion, dynamic changes in budding pattern during filamentous growth induced corresponding changes in fMAPK activity. Intrinsic compromise of bud-site selection also impacted fMAPK activity. Therefore, a surveillance mechanism monitors spatial position in response to extrinsic and intrinsic stress and modulates the response through a differentiation MAPK pathway. PMID:27001830

  1. Ca2+-Dependent Cytoprotective Effects of Ursodeoxycholic and Tauroursodeoxycholic Acid on the Biliary Epithelium in a Rat Model of Cholestasis and Loss of Bile Ducts

    PubMed Central

    Marzioni, Marco; Francis, Heather; Benedetti, Antonio; Ueno, Yoshiyuki; Fava, Giammarco; Venter, Juliet; Reichenbach, Ramona; Mancino, Maria Grazia; Summers, Ryun; Alpini, Gianfranco; Glaser, Shannon

    2006-01-01

    Chronic cholestatic liver diseases are characterized by impaired balance between proliferation and death of cholangiocytes, as well as vanishing of bile ducts and liver failure. Ursodeoxycholic acid (UDCA) is a bile acid widely used for the therapy of cholangiopathies. However, little is known of the cytoprotective effects of UDCA on cholangiocytes. Therefore, UDCA and its taurine conjugate tauroursodeoxycholic acid (TUDCA) were administered in vivo to rats simultaneously subjected to bile duct ligation and vagotomy, a model that induces cholestasis and loss of bile ducts by apoptosis of cholangiocytes. Because these two bile acids act through Ca2+ signaling, animals were also treated with BAPTA/AM (an intracellular Ca2+ chelator) or Gö6976 (a Ca2+-dependent protein kinase C-α inhibitor). The administration of UDCA or TUDCA prevented the induction of apoptosis and the loss of proliferative and functional responses observed in the bile duct ligation-vagotomized rats. These effects were neutralized by the simultaneous administration of BAPTA/AM or Gö6976. UDCA and TUDCA enhanced intracellular Ca2+ and IP3 levels, together with increased phosphorylation of protein kinase C-α. Parallel changes were observed regarding the activation of the MAPK and PI3K pathways, changes that were abolished by addition of BAPTA/AM or Gö6976. These studies provide information that may improve the response of cholangiopathies to medical therapy. PMID:16436655

  2. Comparative analysis of the role of small G proteins in cell migration and cell death: Cytoprotective and promigratory effects of RalA

    SciTech Connect

    Jeon, Hyejin; Zheng, Long Tai; Lee, Shinrye; Lee, Won-Ha; Park, Nammi; Park, Jae-Yong; Heo, Won Do; Lee, Myung-Shik; Suk, Kyoungho

    2011-08-15

    Small G protein superfamily consists of more than 150 members, and is classified into six families: the Ras, Rho, Rab, Arf, Ran, and RGK families. They regulate a wide variety of cell functions such as cell proliferation/differentiation, cytoskeletal reorganization, vesicle trafficking, nucleocytoplasmic transport and microtubule organization. The small G proteins have also been shown to regulate cell death/survival and cell shape. In this study, we compared the role of representative members of the six families of small G proteins in cell migration and cell death/survival, two cellular phenotypes that are associated with inflammation, tumorigenesis, and metastasis. Our results show that small G proteins of the six families differentially regulate cell death and cell cycle distribution. In particular, our results indicate that Rho family of small G proteins is antiapoptotic. Ras, Rho, and Ran families promoted cell migration. There was no significant correlation between the cell death- and cell migration-regulating activities of the small G proteins. Nevertheless, RalA was not only cytoprotective against multiple chemotherapeutic drugs, but also promigratory inducing stress fiber formation, which was accompanied by the activation of Akt and Erk pathways. Our study provides a framework for further systematic investigation of small G proteins in the perspectives of cell death/survival and motility in inflammation and cancer.

  3. Dexmedetomidine controls systemic cytokine levels through the cholinergic anti-inflammatory pathway.

    PubMed

    Xiang, Hui; Hu, Bo; Li, Zhifeng; Li, Jianguo

    2014-10-01

    Previous studies have shown that dexmedetomidine exerted anti-inflammatory effect on several animal models with inflammation, but the mechanism is not clear. This study intends to elucidate the anti-inflammatory mechanism of dexmedetomidine through the cholinergic anti-inflammatory pathway. To investigate this therapeutic potential of dexmedetomidine, a murine model of endotoxemia was established induced by lipopolysaccharide (LPS). Animals were assigned to one of four protocols. Protocol one: animals were randomly assigned to control group, dexmedetomidine group, and sterile saline group (n=20 each), and these animals were used for survival analysis. The survival rate was assessed up to 120 h after endotoxin injection. Protocol two: animals were randomly assigned to one of four groups (n=16 each): group 1 (group Saline), treated with sterile saline 15 min prior to endotoxin treatment (10 mg kg(-1) over 2 min); group 2 (group Dex), treated with dexmedetomidine 15 min prior to endotoxin treatment; group 3 (group αBGT+Dex), treated with alpha-7 nicotinic acetylcholine receptors (α7nAChR) antagonist alpha-bungarotoxin (αBGT, 1 μg/kg) 15 min prior to dexmedetomidine treatment; group 4 (group saline+Dex), treated with equivalent sterile saline 15 min prior to dexmedetomidine treatment. Protocol three: animals were randomly assigned to one of two groups (n=16 each): vagotomy group (group VNX+Dex), right cervical vagus nerve was exposed and transected; sham-operated group (group SHAM+Dex), the cervical vagus nerve was visualized, but was neither isolated from the surrounding tissues nor transected. Protocol four: animals were treated with dexmedetomidine (40 μg/kg) and sterile saline to observe the discharge activity of cervical vagus nerves by using BL-420F data acquisition and analysis system (n=16 each). In the survival analysis groups, the survival rate of dexmedetomidine group was significantly higher than that of the endotoxemia group (65 versus 25 %, P<0

  4. Cross-talk Between Nitrate-Nitrite-NO and NO Synthase Pathways in Control of Vascular NO Homeostasis.

    PubMed

    Carlström, Mattias; Liu, Ming; Yang, Ting; Zollbrecht, Christa; Huang, Liyue; Peleli, Maria; Borniquel, Sara; Kishikawa, Hiroaki; Hezel, Michael; Persson, A Erik G; Weitzberg, Eddie; Lundberg, Jon O

    2015-08-01

    Inorganic nitrate and nitrite from endogenous and dietary sources have emerged as alternative substrates for nitric oxide (NO) formation in addition to the classic L-arginine NO synthase (NOS)-dependent pathway. Here, we investigated a potential cross-talk between these two pathways in the regulation of vascular function. Long-term dietary supplementation with sodium nitrate (0.1 and 1 mmol kg(-1) day(-1)) in rats caused a reversible dose-dependent reduction in phosphorylated endothelial NOS (eNOS) (Ser1177) in aorta and a concomitant increase in phosphorylation at Thr495. Moreover, eNOS-dependent vascular responses were attenuated in vessels harvested from nitrate-treated mice or when nitrite was acutely added to control vessels. The citrulline-to-arginine ratio in plasma, as a measure of eNOS activity, was reduced in nitrate-treated rodents. Telemetry measurements revealed that a low dietary nitrate dose reduced blood pressure, whereas a higher dose was associated with a paradoxical elevation. Finally, plasma cyclic guanosine monophosphate increased in mice that were treated with a low dietary nitrate dose and decreased with a higher dose. These results demonstrate the existence of a cross-talk between the nitrate-nitrite-NO pathway and the NOS-dependent pathway in control of vascular NO homeostasis.

  5. Cross-talk Between Nitrate-Nitrite-NO and NO Synthase Pathways in Control of Vascular NO Homeostasis

    PubMed Central

    Liu, Ming; Yang, Ting; Zollbrecht, Christa; Huang, Liyue; Peleli, Maria; Borniquel, Sara; Kishikawa, Hiroaki; Hezel, Michael; Persson, A. Erik G.; Weitzberg, Eddie; Lundberg, Jon O.

    2015-01-01

    Abstract Aims: Inorganic nitrate and nitrite from endogenous and dietary sources have emerged as alternative substrates for nitric oxide (NO) formation in addition to the classic L-arginine NO synthase (NOS)-dependent pathway. Here, we investigated a potential cross-talk between these two pathways in the regulation of vascular function. Results: Long-term dietary supplementation with sodium nitrate (0.1 and 1 mmol kg−1 day−1) in rats caused a reversible dose-dependent reduction in phosphorylated endothelial NOS (eNOS) (Ser1177) in aorta and a concomitant increase in phosphorylation at Thr495. Moreover, eNOS-dependent vascular responses were attenuated in vessels harvested from nitrate-treated mice or when nitrite was acutely added to control vessels. The citrulline-to-arginine ratio in plasma, as a measure of eNOS activity, was reduced in nitrate-treated rodents. Telemetry measurements revealed that a low dietary nitrate dose reduced blood pressure, whereas a higher dose was associated with a paradoxical elevation. Finally, plasma cyclic guanosine monophosphate increased in mice that were treated with a low dietary nitrate dose and decreased with a higher dose. Innovation and Conclusions: These results demonstrate the existence of a cross-talk between the nitrate-nitrite-NO pathway and the NOS-dependent pathway in control of vascular NO homeostasis. Antioxid. Redox Signal. 23, 295–306. PMID:24224525

  6. Acetate fluxes in Escherichia coli are determined by the thermodynamic control of the Pta-AckA pathway

    PubMed Central

    Enjalbert, Brice; Millard, Pierre; Dinclaux, Mickael; Portais, Jean-Charles; Létisse, Fabien

    2017-01-01

    Escherichia coli excretes acetate upon growth on fermentable sugars, but the regulation of this production remains elusive. Acetate excretion on excess glucose is thought to be an irreversible process. However, dynamic 13C-metabolic flux analysis revealed a strong bidirectional exchange of acetate between E. coli and its environment. The Pta-AckA pathway was found to be central for both flux directions, while alternative routes (Acs or PoxB) play virtually no role in glucose consumption. Kinetic modelling of the Pta-AckA pathway predicted that its flux is thermodynamically controlled by the extracellular acetate concentration in vivo. Experimental validations confirmed that acetate production can be reduced and even reversed depending solely on its extracellular concentration. Consistently, the Pta-AckA pathway can rapidly switch from acetate production to consumption. Contrary to current knowledge, E. coli is thus able to co-consume glucose and acetate under glucose excess. These metabolic capabilities were confirmed on other glycolytic substrates which support the growth of E. coli in the gut. These findings highlight the dual role of the Pta-AckA pathway in acetate production and consumption during growth on glycolytic substrates, uncover a novel regulatory mechanism that controls its flux in vivo, and significantly expand the metabolic capabilities of E. coli. PMID:28186174

  7. Optical angular constancy is maintained as a navigational control strategy when pursuing robots moving along complex pathways.

    PubMed

    Wang, Wei; McBeath, Michael K; Sugar, Thomas G

    2015-03-24

    The optical navigational control strategy used to intercept moving targets was explored using a real-world object that travels along complex, evasive pathways. Fielders ran across a gymnasium attempting to catch a moving robot that varied in speed and direction, while ongoing position was measured using an infrared motion-capture system. Fielder running paths were compared with the predictions of three lateral control models, each based on maintaining a particular optical angle relative to the robotic target: (a) constant alignment angle (CAA), (b) constant eccentricity angle (CEA), and (c) linear optical trajectory (LOT). Findings reveal that running pathways were most consistent with maintenance of LOT and least consistent with CEA. This supports that fielders use the same optical control strategy of maintaining angular constancy using a LOT when navigating toward targets moving along complex pathways as when intercepting simple ballistic trajectories. In those cases in which a target dramatically deviates from its optical path, fielders appear to simply reset LOT parameters using a new constant angle value. Maintenance of such optical angular constancy has now been shown to work well with ballistic, complex, and evasive moving targets, confirming the LOT strategy as a robust, general-purpose optical control mechanism for navigating to intercept catchable targets, both airborne and ground based. © 2015 ARVO.

  8. The Wnt Pathway Controls Cell Death Engulfment, Spindle Orientation, and Migration through CED-10/Rac

    PubMed Central

    Cabello, Juan; Neukomm, Lukas J.; Günesdogan, Ufuk; Burkart, Katharina; Charette, Steve J.; Lochnit, Günter; Hengartner, Michael O.; Schnabel, Ralf

    2010-01-01

    Wnt signalling pathways have extremely diverse functions in animals, including induction of cell fates or tumours, guidance of cell movements during gastrulation, and the induction of cell polarity. Wnt can induce polar changes in cellular morphology by a remodelling of the cytoskeleton. However, how activation of the Frizzled receptor induces cytoskeleton rearrangement is not well understood. We show, by an in depth 4-D microscopy analysis, that the Caenorhabditis elegans Wnt pathway signals to CED-10/Rac via two separate branches to regulate modulation of the cytoskeleton in different cellular situations. Apoptotic cell clearance and migration of the distal tip cell require the MOM-5/Fz receptor, GSK-3 kinase, and APC/APR-1, which activate the CED-2/5/12 branch of the engulfment machinery. MOM-5 (Frizzled) thus can function as an engulfment receptor in C. elegans. Our epistatic analyses also suggest that the two partially redundant signalling pathways defined earlier for engulfment may act in a single pathway in early embryos. By contrast, rearrangement of mitotic spindles requires the MOM-5/Fz receptor, GSK-3 kinase, and β-catenins, but not the downstream factors LIT-1/NLK or POP-1/Tcf. Taken together, our results indicate that in multiple developmental processes, CED-10/Rac can link polar signals mediated by the Wnt pathway to rearrangements of the cytoskeleton. PMID:20126385

  9. The Opa1-Dependent Mitochondrial Cristae Remodeling Pathway Controls Atrophic, Apoptotic, and Ischemic Tissue Damage

    PubMed Central

    Varanita, Tatiana; Soriano, Maria Eugenia; Romanello, Vanina; Zaglia, Tania; Quintana-Cabrera, Rubén; Semenzato, Martina; Menabò, Roberta; Costa, Veronica; Civiletto, Gabriele; Pesce, Paola; Viscomi, Carlo; Zeviani, Massimo; Di Lisa, Fabio; Mongillo, Marco; Sandri, Marco; Scorrano, Luca

    2015-01-01

    Summary Mitochondrial morphological and ultrastructural changes occur during apoptosis and autophagy, but whether they are relevant in vivo for tissue response to damage is unclear. Here we investigate the role of the optic atrophy 1 (OPA1)-dependent cristae remodeling pathway in vivo and provide evidence that it regulates the response of multiple tissues to apoptotic, necrotic, and atrophic stimuli. Genetic inhibition of the cristae remodeling pathway in vivo does not affect development, but protects mice from denervation-induced muscular atrophy, ischemic heart and brain damage, as well as hepatocellular apoptosis. Mechanistically, OPA1-dependent mitochondrial cristae stabilization increases mitochondrial respiratory efficiency and blunts mitochondrial dysfunction, cytochrome c release, and reactive oxygen species production. Our results indicate that the OPA1-dependent cristae remodeling pathway is a fundamental, targetable determinant of tissue damage in vivo. PMID:26039448

  10. Control of YAP/TAZ Activity by Metabolic and Nutrient-Sensing Pathways.

    PubMed

    Santinon, Giulia; Pocaterra, Arianna; Dupont, Sirio

    2016-04-01

    Metabolism is a fundamental cellular function that can be reprogrammed by signaling pathways and oncogenes to meet cellular requirements. An emerging paradigm is that signaling and transcriptional networks can be in turn regulated by metabolism, allowing cells to coordinate their metabolism and behavior in an integrated manner. The activity of the YAP/TAZ transcriptional coactivators, downstream transducers of the Hippo cascade and powerful pro-oncogenic factors, was recently found to be regulated by metabolic pathways, such as aerobic glycolysis and mevalonate synthesis, and by the nutrient-sensing LKB1-AMPK and TSC-mTOR pathways. We discuss here current data linking YAP/TAZ to metabolism and suggest how this coupling might coordinate nutrient availability with genetic programs that sustain tissue growth, neoplastic cell proliferation, and tumor malignancy.

  11. Genomic organization of the structural genes controlling the astaxanthin biosynthesis pathway of Xanthophyllomyces dendrorhous.

    PubMed

    Niklitschek, Mauricio; Alcaíno, Jennifer; Barahona, Salvador; Sepúlveda, Dionisia; Lozano, Carla; Carmona, Marisela; Marcoleta, Andrés; Martínez, Claudio; Lodato, Patricia; Baeza, Marcelo; Cifuentes, Víctor

    2008-01-01

    The cloning and nucleotide sequence of the genes (idi, crtE, crtYB, crtl and crtS) controlling the astaxanthin biosynthesis pathway of the wild-type ATCC 24230 strain of Xanthophyllomyces dendrorhous in their genomic and cDNA version were obtained. The idi, crtE, crtYB, crtl and crtS genes were cloned, as fragments of 10.9, 11.5, 15.8, 5.9 and 4 kb respectively. The nucleotide sequence data analysis indicates that the idi, crtE, crtYB, crtl and crtS genes have 4, 8,4, 11, and 17 introns and 5, 9, 5, 12 and 18 exons respectively. In addition, a highly efficient site-directed mutagenesis system was developed by transformation by integration, followed by mitotic recombination (the double recombinant method). Heterozygote idi (idi+/idi-::hph), crtE (crtE+/crtE-::hph), crtYB (crtYB+/crtYB-::hph), crtI (crtI+/crtI-::hph) and crtS (crtS+/crtS-::hph) and homozygote mutants crtYB (crtYB-::hph/crtYB-::hph), crtI (crtI-::hph/crtI-::hph) and crtS (crtS-::hph/crtS-::hph) were constructed. All the heterozygote mutants have a pale phenotype and produce less carotenoids than the wild-type strain. The genetic analysis of the crtYB, crtl and crtS loci in the wild-type, heterozygote, and homozygote give evidence of the diploid constitution of ATCC 24230 strains. In addition, the cloning of a truncated form of the crtYB that lacks 153 amino acids of the N-terminal region derived from alternatively spliced mRNA was obtained. Their heterologous expression in Escherichia coli carrying the carotenogenic cluster of Erwinia uredovora result in trans-complementation and give evidence of its functionality in this bacterium, maintaining its phytoene synthase activity but not the lycopene cyclase activity.

  12. A novel strategy to activate cytoprotective genes in the injured brain

    SciTech Connect

    Zhao, Jing; Redell, John B.; Moore, Anthony N.; Dash, Pramod K.

    2011-04-15

    Highlights: {yields} A strategy to increase cytoprotective gene expression in injured tissue is outlined. {yields} A peptide containing a DEETGE motif can increase Nrf2 responsive genes in vivo. {yields} Gene expression in injured brains requires a calpain cleavage site. {yields} This peptide decreases BBB compromise when infused pre- or post-brain injury. {yields} Cleavage sites for disease-specific proteases could be used to treat that condition. -- Abstract: The transcription factor nuclear factor E2-related factor 2 (Nrf2) regulates the expression of multiple cytoprotective genes that have been shown to offer protection in response to a number of insults. The present study describes a novel strategy to increase expression of Nrf2-responsive genes in brain injured mice. Under normal conditions, the adapter protein Kelch-like ECH-associated protein 1 (Keap1) binds to Nrf2 and promotes its proteosomal degradation in the cytoplasm. The amino acid sequence DEETGE, located at amino acid 77-82 of Nrf2, is critical for Nrf2-Keap1 interaction, and synthetic peptides containing this sequence can be used to disrupt the complex in vitro. We observed that intracerebroventricular (i.c.v.) infusion of a peptide containing the DEETGE sequence along with the cell transduction domain of the HIV-TAT protein (TAT-DEETGE) into brain-injured mice did not increase the mRNA levels for Nrf2-driven genes. However, when a calpain cleavage sequence was introduced between the TAT sequence and the DEETGE sequence, the new peptide (TAT-CAL-DEETGE) increased the mRNA levels of these genes. Increased gene expression was not observed when the TAT-CAL-DEETGE peptide was injected into uninjured animals. Furthermore, injection of TAT-CAL-DEETGE peptides before or after brain injury reduced blood-brain barrier compromise, a prominent secondary pathology that negatively influences outcome. The present strategy to increase Nrf2-responsive gene expression can be adapted to treat other insults or

  13. Reciprocal Control of Thyroid Binding and the Pipecolate Pathway in the Brain.

    PubMed

    Hallen, André; Cooper, Arthur J L

    2017-01-01

    Thyroid hormones have long been known to play an essential role in brain growth and development, with cytoplasmic thyroid hormone binding proteins (THBPs) playing a critical role in thyroid hormone bioavailability. A major mammalian THBP is μ-crystallin (CRYM), which was originally characterized by its ability to strongly bind thyroid hormones in an NADPH-dependent fashion. However, in 2011 it was discovered that CRYM is also an enzyme, namely ketimine reductase (KR), which catalyzes the NAD(P)H-dependent reduction of -C=N- (imine) double bonds of a number of cyclic ketimine substrates including sulfur-containing cyclic ketimines. The enzyme activity was also shown to be potently inhibited by thyroid hormones, thus suggesting a novel reciprocal relationship between enzyme catalysis and thyroid hormone bioavailability. KR is involved in a number of amino acid metabolic pathways. However, the best documented biological function of KR is its role as a ∆(1)-piperideine-2-carboxylate (P2C) reductase in the pipecolate pathway of lysine metabolism. The pipecolate pathway is the main L-lysine degradation pathway in the adult brain, whereas the saccharopine pathway predominates in extracerebral tissues and in infant brain, suggesting that KR has evolved to perform specific and important roles in neural development and function. The potent regulation of KR activity by thyroid hormones adds further weight to this suggestion. KR is also involved in L-ornithine/L-glutamate/L-proline metabolism as well as sulfur-containing amino acid metabolism. This review describes the pipecolate pathway and recent discoveries related to mammalian KR function, which have important implications in normal and pathological brain functions.

  14. Human Papillomavirus Episome Stability Is Reduced by Aphidicolin and Controlled by DNA Damage Response Pathways

    PubMed Central

    Edwards, Terri G.; Helmus, Michael J.; Koeller, Kevin; Bashkin, James K.

    2013-01-01

    A highly reproducible quantitative PCR (Q-PCR) assay was used to study the stability of human papillomavirus (HPV) in undifferentiated keratinocytes that maintain viral episomes. The term “stability” refers to the ability of episomes to persist with little copy number variation in cells. In investigating the mechanism of action of PA25, a previously published compound that destabilizes HPV episomes, aphidicolin was also found to markedly decrease episome levels, but via a different pathway from that of PA25. Since aphidicolin is known to activate DNA damage response (DDR) pathways, effects of inhibitors and small interfering RNAs (siRNAs) acting within DDR pathways were investigated. Inhibitors of Chk1 and siRNA directed against ataxia-telangiectasia mutated (ATM) and ataxia-telangiectasia Rad3-related (ATR) pathways significantly reduced viral episomes, suggesting that these pathways play a role in maintaining HPV episome stability. Inhibitors of Chk2 and DNA-PK had no effect on episome levels. Pharmacological inhibition of ATM proteins had no effect on episome levels, but ATM knockdown by siRNA significantly reduced episome levels, suggesting that ATM proteins are playing an important role in HPV episome stability that does not require kinase activity. These results outline two pathways that trigger episome loss from cells and suggest the existence of a little-understood mechanism that mediates viral DNA elimination. Together, our results also indicate that HPV episomes have a stability profile that is remarkably similar to that of fragile sites; these similarities are outlined and discussed. This close correspondence may influence the preference of HPV for integration into fragile sites. PMID:23365423

  15. Loss of the six3/6 controlling pathways might have resulted in pinhole-eye evolution in Nautilus.

    PubMed

    Ogura, Atsushi; Yoshida, Masa-aki; Moritaki, Takeya; Okuda, Yuki; Sese, Jun; Shimizu, Kentaro K; Sousounis, Konstantinos; Tsonis, Panagiotis A

    2013-01-01

    Coleoid cephalopods have an elaborate camera eye whereas nautiloids have primitive pinhole eye without lens and cornea. The Nautilus pinhole eye provides a unique example to explore the module of lens formation and its evolutionary mechanism. Here, we conducted an RNA-seq study of developing eyes of Nautilus and pygmy squid. First, we found that evolutionary distances from the common ancestor to Nautilus or squid are almost the same. Although most upstream eye development controlling genes were expressed in both species, six3/6 that are required for lens formation in vertebrates was not expressed in Nautilus. Furthermore, many downstream target genes of six3/6 including crystallin genes and other lens protein related genes were not expressed in Nautilus. As six3/6 and its controlling pathways are widely conserved among molluscs other than Nautilus, the present data suggest that deregulation of the six3/6 pathway led to the pinhole eye evolution in Nautilus.

  16. Loss of the six3/6 controlling pathways might have resulted in pinhole-eye evolution in Nautilus

    PubMed Central

    Ogura, Atsushi; Yoshida, Masa-aki; Moritaki, Takeya; Okuda, Yuki; Sese, Jun; Shimizu, Kentaro K.; Sousounis, Konstantinos; Tsonis, Panagiotis A.

    2013-01-01

    Coleoid cephalopods have an elaborate camera eye whereas nautiloids have primitive pinhole eye without lens and cornea. The Nautilus pinhole eye provides a unique example to explore the module of lens formation and its evolutionary mechanism. Here, we conducted an RNA-seq study of developing eyes of Nautilus and pygmy squid. First, we found that evolutionary distances from the common ancestor to Nautilus or squid are almost the same. Although most upstream eye development controlling genes were expressed in both species, six3/6 that are required for lens formation in vertebrates was not expressed in Nautilus. Furthermore, many downstream target genes of six3/6 including crystallin genes and other lens protein related genes were not expressed in Nautilus. As six3/6 and its controlling pathways are widely conserved among molluscs other than Nautilus, the present data suggest that deregulation of the six3/6 pathway led to the pinhole eye evolution in Nautilus. PMID:23478590

  17. Tor1 and CK2 kinases control a switch between alternative ribosome biogenesis pathways in a growth-dependent manner

    PubMed Central

    Kos-Braun, Isabelle C.; Jung, Ilona; Koš, Martin

    2017-01-01

    Ribosome biogenesis is a major energy-consuming process in the cell that has to be rapidly down-regulated in response to stress or nutrient depletion. The target of rapamycin 1 (Tor1) pathway regulates synthesis of ribosomal RNA (rRNA) at the level of transcription initiation. It remains unclear whether ribosome biogenesis is also controlled directly at the posttranscriptional level. We show that Tor1 and casein kinase 2 (CK2) kinases regulate a rapid switch between a productive and a non-productive pre-rRNA processing pathways in yeast. Under stress, the pre-rRNA continues to be synthesized; however, it is processed differently, and no new ribosomes are produced. Strikingly, the control of the switch does not require the Sch9 kinase, indicating that an unrecognized Tor Complex 1 (TORC1) signaling branch involving CK2 kinase directly regulates ribosome biogenesis at the posttranscriptional level. PMID:28282370

  18. Cytoprotective Effect of Caffeic Acid Phenethyl Ester (CAPE) and Catechol Ring-Fluorinated CAPE Derivatives Against Menadione-Induced Oxidative Stress in Human Endothelial Cells

    DTIC Science & Technology

    2006-03-31

    chlorogenic acid , and rosmari- nic acid did not display any cytoprotective effect in this assay at 15 lM (data not shown). Within the same pas- sage of HUVEC...Cytoprotective effect of caffeic acid phenethyl ester (CAPE) and catechol ring-fluorinated CAPE derivatives against menadione-induced oxidative...accepted 13 March 2006 Available online 31 March 2006 Abstract—Caffeic acid phenethyl ester (CAPE), a natural polyphenolic compound with many

  19. Role of Direct vs. Indirect Pathways from the Motor Cortex to Spinal Motoneurons in the Control of Hand Dexterity

    PubMed Central

    Isa, Tadashi; Kinoshita, Masaharu; Nishimura, Yukio

    2013-01-01

    Evolutionally, development of the direct connection from the motor cortex to spinal motoneurons [corticomotoneuronal (CM) pathway] parallels the ability of hand dexterity. Damage to the corticofugal fibers in higher primates resulted in deficit of fractionated digit movements. Based on such observations, it was generally believed that the CM pathway plays a critical role in the control of hand dexterity. On the other hand, a number of “phylogenetically older” indirect pathways from the motor cortex to motoneurons still exist in primates. The indirect pathways are mediated by intercalated neurons such as segmental interneurons (sINs), propriospinal neurons (PNs) reticulospinal neurons (RSNs), or rubrospinal neurons (RuSNs). However, their contribution to hand dexterity remains elusive. Lesion of the brainstem pyramid sparing the transmission through the RuSNs and RSNs, resulted in permanent deficit of fractionated digit movements in macaque monkeys. On the other hand, in our recent study, after lesion of the dorsolateral funiculus (DLF) at the C5 segment, which removed the lateral corticospinal tract (l-CST) including the CM pathway and the transmission through sINs and RuSNs but spared the processing through the PNs and RSNs, fractionated digit movements recovered within several weeks. These results suggest that the PNs can be involved in the recovery of fractionated digit movements, but the RSNs and RuSNs have less capacity in this regard. However, on closer inspection, it was found that the activation pattern of hand and arm muscles considerably changed after the C5 lesion, suggesting limitation of PNs for the compensation of hand dexterity. Altogether, it is suggested that PNs, RSNs RuSNs, and the CM pathway (plus sINs) make a different contribution to the hand dexterity and appearance of motor deficit of the hand dexterity caused by damage to the corticofugal fibers and potential of recovery varies depending on the rostrocaudal level of the lesion. PMID

  20. Localized and Controlled Delivery of Nitric Oxide to the Conventional Outflow Pathway via Enzyme Biocatalysis: Toward Therapy for Glaucoma.

    PubMed

    Chandrawati, Rona; Chang, Jason Y H; Reina-Torres, Ester; Jumeaux, Coline; Sherwood, Joseph M; Stamer, W Daniel; Zelikin, Alexander N; Overby, Darryl R; Stevens, Molly M

    2017-04-01

    Nitric oxide (NO) is able to lower intraocular pressure (IOP); however, its therapeutic effects on outflow physiology are location- and dose-dependent. A NO delivery platform that directly targets the resistance-generating region of the conventional outflow pathway and locally liberates a controlled dose of NO is reported. An increase in outflow facility (decrease in IOP) is demonstrated in a mouse model. © 2017 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Radiation-induced craniofacial bone growth inhibition: acute and long-term effects on bone histopathology with and without cytoprotection.

    PubMed

    Oʼdonovan, David A; La Scala, Giorgio C; Leong, Iona; Mendes, Maria; Rogers, Marianne; Pritzker, Kenneth H; Yeung, Ivan; Pang, Cho Y; Neligan, Peter C; Forrest, Christopher R

    2012-04-01

    The authors previously established an animal model of radiation-induced craniofacial bone growth inhibition and demonstrated the effectiveness of cytoprotection in preserving growth using amifostine, but the mechanism is unclear. The objective of this study was to investigate the acute and long-term histopathologic effects of single-dose orthovoltage irradiation on craniofacial bone with and without cytoprotection. Sixty infant New Zealand White rabbits (7-week-old) were randomized into three groups (n = 20 per group): group 1, 0-Gy, sham irradiation; group 2, 35-Gy single-dose orthovoltage irradiation; and group 3, cytoprotection with amifostine before irradiation. Orbitozygomatic complex bone was harvested from animals 12 hours after irradiation and at skeletal maturity (21 weeks of age). Histologic parameters measured included native bone cell (osteoblast, osteoclast, and osteocyte) populations, periosteal proliferation indices (MIB-1 stains), bone turnover rates [triple fluorochromes: tetracycline administered at 7 weeks of age (before irradiation), alizarin complexone at 12 weeks, and calcein at 16 weeks of age], and endosteal space fibrosis levels. Orthovoltage irradiation significantly (p < 0.05) reduced osteoblast and osteoclast counts 12 hours after irradiation (age, 7 weeks) with or without pretreatment with amifostine but had no effect on osteocyte populations. Long-term analysis at age 21 weeks demonstrated significantly (p < 0.05) increased osteoblast counts, reduced endosteal space fibrosis, reduced periosteal proliferation indices, and improved bone turnover (fluorochrome stains) in amifostine-treated animals. This study suggests that amifostine cytoprotection is mediated through a combination of reduced cellular injury with enhanced promotion of cellular bone rebuilding potential.

  2. A Set of Activators and Repressors Control Peripheral Glucose Pathways in Pseudomonas putida To Yield a Common Central Intermediate▿

    PubMed Central

    del Castillo, Teresa; Duque, Estrella; Ramos, Juan L.

    2008-01-01

    Pseudomonas putida KT2440 channels glucose to the central Entner-Doudoroff intermediate 6-phosphogluconate through three convergent pathways. The genes for these convergent pathways are clustered in three independent regions on the host chromosome. A number of monocistronic units and operons coexist within each of these clusters, favoring coexpression of catabolic enzymes and transport systems. Expression of the three pathways is mediated by three transcriptional repressors, HexR, GnuR, and PtxS, and by a positive transcriptional regulator, GltR-2. In this study, we generated mutants in each of the regulators and carried out transcriptional assays using microarrays and transcriptional fusions. These studies revealed that HexR controls the genes that encode glucokinase/glucose 6-phosphate dehydrogenase that yield 6-phosphogluconate; the genes for the Entner-Doudoroff enzymes that yield glyceraldehyde-3-phosphate and pyruvate; and gap-1, which encodes glyceraldehyde-3-phosphate dehydrogenase. GltR-2 is the transcriptional regulator that controls specific porins for the entry of glucose into the periplasmic space, as well as the gtsABCD operon for glucose transport through the inner membrane. GnuR is the repressor of gluconate transport and gluconokinase responsible for the conversion of gluconate into 6-phosphogluconate. PtxS, however, controls the enzymes for oxidation of gluconate to 2-ketogluconate, its transport and metabolism, and a set of genes unrelated to glucose metabolism. PMID:18245293

  3. SWITCH: a dynamic CRISPR tool for genome engineering and metabolic pathway control for cell factory construction in Saccharomyces cerevisiae.

    PubMed

    Vanegas, Katherina García; Lehka, Beata Joanna; Mortensen, Uffe Hasbro

    2017-02-08

    The yeast Saccharomyces cerevisiae is increasingly used as a cell factory. However, cell factory construction time is a major obstacle towards using yeast for bio-production. Hence, tools to speed up cell factory construction are desirable. In this study, we have developed a new Cas9/dCas9 based system, SWITCH, which allows Saccharomyces cerevisiae strains to iteratively alternate between a genetic engineering state and a pathway control state. Since Cas9 induced recombination events are crucial for SWITCH efficiency, we first developed a technique TAPE, which we have successfully used to address protospacer efficiency. As proof of concept of the use of SWITCH in cell factory construction, we have exploited the genetic engineering state of a SWITCH strain to insert the five genes necessary for naringenin production. Next, the naringenin cell factory was switched to the pathway control state where production was optimized by downregulating an essential gene TSC13, hence, reducing formation of a byproduct. We have successfully integrated two CRISPR tools, one for genetic engineering and one for pathway control, into one system and successfully used it for cell factory construction.

  4. Cytoprotective properties of traditional Chinese medicinal herbal extracts in hydrogen peroxide challenged human U373 astroglia cells.

    PubMed

    Steele, Megan L; Truong, John; Govindaraghavan, Suresh; Ooi, Lezanne; Sucher, Nikolaus J; Münch, Gerald

    2013-04-01

    Age is the leading risk factor for many of the most prevalent and devastating diseases including neurodegenerative diseases. A number of herbal medicines have been used for centuries to ameliorate the deleterious effects of ageing-related diseases and increase longevity. Oxidative stress is believed to play a role in normal ageing as well as in neurodegenerative processes. Since many of the constituents of herbal extracts are known antioxidants, it is believed that restoring oxidative balance may be one of the underlying mechanisms by which medicinal herbs can protect against ageing and cognitive decline. Based on the premise that astrocytes are key modulators in the progression of oxidative stress associated neurodegenerative diseases, 13 herbal extracts purported to possess anti-ageing properties were tested for their ability to protect U373 human astrocytes from hydrogen peroxide induced cell death. To determine the contribution of antioxidant activity to the cytoprotective ability of extracts, total phenol content and radical scavenging capacities of extracts were examined. Polygonum multiflorum, amongst others, was identified as possessing potent antioxidant and cytoprotective properties. Not surprisingly, total phenol content of extracts was strongly correlated with antioxidant capacity. Interestingly, when total phenol content and radical scavenging capacities of extracts were compared to the cytoprotective properties of extracts, only moderately strong correlations were observed. This finding suggests the involvement of multiple protective mechanisms in the beneficial effects of these medicinal herbs. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Cytotoxic bile acids, but not cytoprotective species, inhibit the ordering effect of cholesterol in model membranes at physiologically active concentrations.

    PubMed

    Mello-Vieira, João; Sousa, Tânia; Coutinho, Ana; Fedorov, Aleksander; Lucas, Susana D; Moreira, Rui; Castro, Rui E; Rodrigues, Cecília M P; Prieto, Manuel; Fernandes, Fábio

    2013-09-01

    Submillimolar concentrations of cytotoxic bile acids (BAs) induce cell death via apoptosis. On the other hand, several cytoprotective BAs were shown to prevent apoptosis in the same concentration range. Still, the mechanisms by which BAs trigger these opposite signaling effects remain unclear. This study was aimed to determine if cytotoxic and cytoprotective BAs, at physiologically active concentrations, are able to modulate the biophysical properties of lipid membranes, potentially translating into changes in the apoptotic threshold of cells. Binding of BAs to membranes was assessed through the variation of fluorescence parameters of suitable derivatized BAs. These derivatives partitioned with higher affinity to liquid disordered than to the cholesterol-enriched liquid ordered domains. Unlabeled BAs were also shown to have a superficial location upon interaction with the lipid membrane. Additionally, the interaction of cytotoxic BAs with membranes resulted in membrane expansion, as concluded from FRET data. Moreover, it was shown that cytotoxic BAs were able to significantly disrupt the ordering of the membrane by cholesterol at physiologically active concentrations of the