Abstract 211: Aldehyde Dehydrogenase 2 Deficiency Aggravates Cardiac Dysfunction Elicited by Endoplasmic Reticulum Stress Induction

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Aijun Sun ◽  
Jianquan Liao ◽  
Xieye Qing ◽  
Xueting Jin ◽  
Toyoshi Isse ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Nadph Oxidase ◽  
Er Stress ◽  
Aldehyde Dehydrogenase ◽  
Cardiac Dysfunction ◽  
Aldehyde Dehydrogenase 2 ◽  
Stress Induction ◽  
Protein Levels ◽  
Stress Markers

Mitochondrial aldehyde dehydrogenase-2 (ALDH2) has been characterized as an important mediator of endogenous cytoprotection in the heart. This study was designed to examine the role of aldehyde dehydrogenase-2 knockout (KO) in the pathogenesis of heart underwent endoplasmic reticulum (ER) stress induction. Wild-type (WT) and ALDH2 KO mice were subjected to tunicamycin challenge and echocardiographic examination was performed. Protein levels of GRP78, p-eIF2α, CHOP, phosphorylation of Akt, p47phox NADPH oxidase, and 4-hydroxynonenal were determined by Western blot analysis. Cytotoxicity and apoptosis were estimated by MTT assay and caspase-3 activity respectively. ALDH2 deficiency exacerbated cardiac dysfunction and increased the protein levels of ER stress markers after ER stress induction characterized by the changes of ejection fraction and fractional shorting, when compared with WT mice. In vitro, tunicamycin significantly increased in the levels of GRP78, p-eIF2, CHOP and p47phox NADPH oxidase, which was exacerbated by ALDH2 knockdown and abolished by ALDH2 overexpression. Overexpression of ALDH2 abrogated tunicamycin-induced dephosphorylation of Akt. Inhibition of PI3-K with LY294002 did not negatively affect the inhibition of ER stress markers conferred by ALDH2, but reversed the anti-apoptotic role of ALDH2, which may be associated with p47phox NADPH oxidase. These results suggest that ALDH2 was implicated in the regulation of ER stress and ER stress-induced apoptosis. The protective role of ALDH2 against cell death induced by ER stress was probably mediated by Akt signaling via p47phox NADPH oxidase. These findings indicate a critical role of ALDH2 in the pathogenesis of ER stress in heart disease.

scholarly journals Rapamycin Improves Palmitate-Induced ER Stress/NFκB Pathways Associated with Stimulating Autophagy in Adipocytes

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Jiajing Yin ◽  
Liping Gu ◽  
Yufan Wang ◽  
Nengguang Fan ◽  
Yuhang Ma ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Nuclear Translocation ◽  
Kinase Inhibitor ◽  
Autophagy Flux ◽  
Protein Levels ◽  
Stress Effects ◽  
Stress Markers

Obesity-induced endoplasmic reticulum (ER) stress and inflammation lead to adipocytes dysfunction. Autophagy helps to adapt to cellular stress and involves in regulating innate inflammatory response. In present study, we examined the activity of rapamycin, a mTOR kinase inhibitor, against endoplasmic reticulum stress and inflammation in adipocytes. Anin vitromodel was used in which 3T3-L1 adipocytes were preloaded with palmitate (PA) to generate artificial hypertrophy mature adipocytes. Elevated autophagy flux and increased number of autophagosomes were observed in response to PA and rapamycin treatment. Rapamycin attenuated PA-induced PERK and IRE1-associated UPR pathways, evidenced by decreased protein levels of eIF2αphosphorylation, ATF4, CHOP, and JNK phosphorylation. Inhibiting autophagy with chloroquine (CQ) exacerbated these ER stress markers, indicating the role of autophagy in ameliorating ER stress. In addition, cotreatment of CQ abolished the anti-ER stress effects of rapamycin, which confirms the effect of rapamycin on ERs is autophagy-dependent. Furthermore, rapamycin decreased PA-induced nuclear translocation of NFκB P65 subunit, thereby NFκB-dependent inflammatory cytokines MCP-1 and IL-6 expression and secretion. In conclusion, rapamycin attenuated PA-induced ER stress/NFκB pathways to counterbalance adipocytes stress and inflammation. The beneficial of rapamycin in this context partly depends on autophagy. Stimulating autophagy may become a way to attenuate adipocytes dysfunction.

scholarly journals Aldehyde Dehydrogenase-2 Deficiency Aggravates Cardiac Dysfunction Elicited by Endoplasmic Reticulum Stress Induction

2012 ◽  
Vol 18 (5) ◽  
pp. 785-793 ◽  
Author(s):  
Jianquan Liao ◽  
Aijun Sun ◽  
Yeqing Xie ◽  
Toyoshi Isse ◽  
Toshihiro Kawamoto ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Aldehyde Dehydrogenase ◽  
Cardiac Dysfunction ◽  
Aldehyde Dehydrogenase 2 ◽  
Stress Induction

scholarly journals Inhibition of Endoplasmic Reticulum Stress Reverses Synaptic Plasticity Deficits in Striatum of DYT1 Dystonia Mice

2021 ◽  
Author(s):  
Huaying Cai ◽  
Linhui Ni ◽  
Xingyue Hu ◽  
Xianjun Ding
Keyword(s):  
Endoplasmic Reticulum ◽  
Synaptic Plasticity ◽  
Er Stress ◽  
Critical Role ◽  
Stress Protein ◽  
Long Term Potentiation ◽  
Research Field ◽  
Protein Levels ◽  
Dyt1 Dystonia

Abstract Background & objectiveStriatal plasticity alterations caused by endoplasmic reticulum (ER) stress is supposed to be critically involved in the mechanism of DYT1 dystonia. In the current study, we expanded this research field by investigating the critical role of ER stress underlying synaptic plasticity impairment imposed by mutant heterozygous Tor1a+/- in a DYT1 dystonia mouse model.Methods & resultsLong-term depression (LTD) was failed to be induced, while long-term potentiation (LTP) was further strengthened in striatal spiny neurons (SPNs) from the Tor1a+/- DYT1 dystonia mice. Spine morphology analyses revealed a significant increase of both number of mushroom type spines and spine width in Tor1a+/- SPNs. In addition, increased AMPA receptor function and the reduction of NMDA/AMPA ratio in the postsynaptic of Tor1a+/- SPNs was observed, along with increased ER stress protein levels in Tor1a+/- striatum. Notably, ER stress inhibitors, tauroursodeoxycholic acid (TUDCA), could rescue LTD as well as AMPA currents.ConclusionThe current study illustrated the role of ER stress in mediating structural and functional plasticity alterations in Tor1a+/- SPNs. Inhibition of the ER stress by TUDCA is beneficial in reversing the deficits at the cellular and molecular levels. Remedy of dystonia associated neurological and motor functional impairment by ER stress inhibitors could be a recommendable therapeutic agent in clinical practice.

scholarly journals Selenoprotein S regulates adipogenesis through IRE1α-XBP1 pathway

2020 ◽  
Vol 244 (3) ◽  
pp. 431-443
Author(s):  
Lili Men ◽  
Junjie Yao ◽  
Shanshan Yu ◽  
Yu Li ◽  
Siyuan Cui ◽  
...  
Keyword(s):  
Er Stress ◽  
Late Phase ◽  
G1 Arrest ◽  
Mrna Levels ◽  
Protein Levels ◽  
Selenoprotein S ◽  
Stress Markers ◽  
Obese Subjects

The induction of endoplasmic reticulum (ER) stress is associated with adipogenesis, during which the inositol-requiring enzyme 1 alpha (IRE1α)-X-box-binding protein 1 (XBP1) pathway is involved. Selenoprotein S (SelS), which is an ER resident selenoprotein, is involved in ER homeostasis regulation; however, little is known about the role of SelS in regulating adipogenesis. In vivo studies showed that SelS protein levels in white adipose tissue were increased in obese subjects and high-fat diet (HFD)-fed mice. Moreover, we identified that SelS protein levels increased in the early phase of adipogenesis and then decreased in the late phase during adipogenesis. Overexpression of SelS promoted adipogenesis. Conversely, knockdown (KD) of SelS resulted in the inhibition of adipogenesis, which was related to increasing cell death, decreased mitotic clonal expansion, and cell cycle G1 arrest. In vivo studies also showed that ER stress markers (p-IRE1α/IRE1α, XBP1s, and Grp78) were significantly increased with upregulating of SelS expression in subcutaneous and visceral adipose tissues in the obese subjects and HFD-fed mice. Furthermore, in SelS KD cells, the levels of Grp78 were increased and the levels of p-IRE1α/IRE1α were unchanged , but mRNA levels of spliced XBP1 (XBP1s) produced by IRE1α-mediated splicing were decreased, suggesting a role of SelS in the modulation of IRE1α-XBP1 pathway. Moreover, inhibition of adipogenesis by SelS suppression can be rescued by overexpression of XBP1s. Thus, SelS appears to function as a novel regulator of adipogenesis through the IRE1α-XBP1 signaling pathway.

Abstract 143: Endoplasmic Reticulum Stress Impairs Vascular Function Through Enhanced Nadph Oxidase Activity and Reduction in Enos Activity

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Maria Galan ◽  
Modar Kassan ◽  
Mohamed Trebak ◽  
Khalid Matrougui
Keyword(s):  
Endoplasmic Reticulum ◽  
Nadph Oxidase ◽  
Er Stress ◽  
P38 Mapk ◽  
Vascular Function ◽  
Oxidase Activity ◽  
Mrna Levels ◽  
Stress Induction ◽  
Nadph Oxidase Activity ◽  
Enos Phosphorylation

Cardiovascular diseases are associated with the induction of endoplasmic reticulum (ER) stress. The induction of ER stress in C57BL/6J and p47phox-/- mice, by the injection of tunicamycin, greatly impaired vascular endothelium-dependent relaxation in C57BL/6J than in p47phox-/- mice. To determine the mechanism by which ER stress impairs endothelium function, we incubated mice primary endothelial cells from coronary arteries (ECs) with tunicamycin (1 μg/mL) for 6 h in the presence or absence of two ER stress inhibitors (Tudca, 500 μg/mL and PBA, 10 mM). Tunicamycin increased the phosphorylation of PERK and eIF2alpha, the expression of CHOP, ATF6 and Bip, Nox2/Nox4 mRNA levels, NADPH oxidase activity and superoxide anion levels. In addition, phosphorylated eNOS and nitrites levels were reduced with tunicamycin. All these events were prevented, at least partially, with the inhibition of ER stress. Tunicamycin treatment or the transfection of ECs with plasmids that express ATF6 or CHOP reduced the luciferase activity of a reporter plasmid containing the eNOS promoter. The ER stress induction reduced ERK1/2 phosphorylation and increased p38 MAPK phosphorylation. The inhibition of p38 MAPK restored the eNOS promoter activity and the eNOS phosphorylation, and reduced Bip but did not affect to ATF6 or CHOP expression. Conclusion: ER stress induction impairs endothelial cell eNOS-dependent activity by oxidative stress and p38 MAPK-dependent mechanisms.

scholarly journals EGFRvIII Promotes Cell Survival during Endoplasmic Reticulum Stress through a Reticulocalbin 1-Dependent Mechanism

Cancers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1198
Author(s):  
Juliana Gomez ◽  
Zammam Areeb ◽  
Sarah F. Stuart ◽  
Hong P. T. Nguyen ◽  
Lucia Paradiso ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Viability ◽  
Er Stress ◽  
Cell Survival ◽  
Glioblastoma Cells ◽  
Over Expression ◽  
Stress Markers ◽  
Apoptotic Protein ◽  
Novel Association ◽  
Reduced Activity

Reticulocalbin 1 (RCN1) is an endoplasmic reticulum (ER)-residing protein, involved in promoting cell survival during pathophysiological conditions that lead to ER stress. However, the key upstream receptor tyrosine kinase that regulates RCN1 expression and its potential role in cell survival in the glioblastoma setting have not been determined. Here, we demonstrate that RCN1 expression significantly correlates with poor glioblastoma patient survival. We also demonstrate that glioblastoma cells with expression of EGFRvIII receptor also have high RCN1 expression. Over-expression of wildtype EGFR also correlated with high RCN1 expression, suggesting that EGFR and EGFRvIII regulate RCN1 expression. Importantly, cells that expressed EGFRvIII and subsequently showed high RCN1 expression displayed greater cell viability under ER stress compared to EGFRvIII negative glioblastoma cells. Consistently, we also demonstrated that RCN1 knockdown reduced cell viability and exogenous introduction of RCN1 enhanced cell viability following induction of ER stress. Mechanistically, we demonstrate that the EGFRvIII-RCN1-driven increase in cell survival is due to the inactivation of the ER stress markers ATF4 and ATF6, maintained expression of the anti-apoptotic protein Bcl-2 and reduced activity of caspase 3/7. Our current findings identify that EGFRvIII regulates RCN1 expression and that this novel association promotes cell survival in glioblastoma cells during ER stress.

The effect of baicalein on endoplasmic reticulum stress and autophagy on liver damage

2021 ◽  
pp. 096032712110036
Author(s):  
MC Üstüner ◽  
C Tanrikut ◽  
D Üstüner ◽  
UK Kolaç ◽  
Z Özdemir Köroğlu ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Transcription Factor ◽  
Er Stress ◽  
Liver Damage ◽  
Albino Rats ◽  
Tem Analysis ◽  
Stress Markers ◽  
Activating Transcription Factor 4 ◽  
Activating Transcription Factor ◽  
Wistar Albino Rats

Carbon tetrachloride (CCl4) is a toxic chemical that causes liver injury. CCl4 triggers endoplasmic reticulum (ER) stress and unfolded protein response (UPR). UPR triggers autophagy to deal with the damage. The aim of this study was to investigate the effect of baicalein, derived from Scutellaria baicalensis, on CCl4-induced liver damage concerning ER stress and autophagy. Two groups of Wistar albino rats (n = 7/groups) were treated with 0.2 ml/kg CCl4 for 10 days with and without baicalein. Histological and transmission electron microscopy (TEM) analysis, autophagy, and ER stress markers measurements were carried out to evaluate the effect of baicalein. Histological examinations showed that baicalein reduced liver damage. TEM analysis indicated that baicalein inhibited ER stress and triggered autophagy. CCl4-induced elevation of C/EBP homologous protein (CHOP), glucose-regulating protein 78 (GRP78), activating transcription factor 4 (ATF4), activating transcription factor 6 (ATF6), inositol requiring enzyme 1 (IRE1), pancreatic ER kinase (PERK), and active/spliced form of X-box-binding protein 1 (XBP1s) ER stress markers were decreased by baicalein. Baicalein also increased the autophagy-related 5 (ATG5), Beclin1, and Microtubule-associated protein 1A/1B-light chain 3-phosphatidylethanolamine-conjugated form (LC3-II) autophagy marker levels. In conclusion, baicalein reduced the CCl4-induced liver damage by inhibiting ER stress and the trigger of autophagy.

scholarly journals Acute Tissue Injury Caused by Subcutaneous Fat Biopsies Produces Endoplasmic Reticulum Stress

2009 ◽  
Vol 30 (7) ◽  
pp. 928-928
Author(s):  
Guenther Boden ◽  
Matthew Silviera ◽  
Brian Smith ◽  
Peter Cheung ◽  
Carol Homko
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Tissue Injury ◽  
Subcutaneous Fat ◽  
Whole Body ◽  
Monocyte Chemoattractant Protein 1 ◽  
Homologous Protein ◽  
Stress Markers ◽  
Acute Tissue Injury ◽  
Glucose Regulated Protein

Abstract Background It is not known whether acute tissue injury is associated with endoplasmic reticulum (ER) stress. Objective Our objective was to determine whether open, sc fat biopsies cause ER stress. Approach Five healthy subjects underwent three open sc fat biopsies. The first biopsy, taken from the lateral aspect of a thigh, was followed 4 h later by a second biopsy from the same incision site and a third biopsy from the contralateral leg. Expression markers of ER stress, inflammation, hypoxia, and adipokines were measured in these fat biopsies. In addition, we tested for signs of systemic ER stress and inflammation in plasma and in circulating monocytes. Results mRNA/18s ratios of IL-6, monocyte chemoattractant protein-1, CD-14, hypoxia-induced factor 1-α, the spliced form of Xbox protein-1, glucose-regulated protein 78, CEBP homologous protein, and activating factor-4 were all severalfold higher, whereas mRNA/18s ratios of adiponectin and leptin were lower in fat biopsies taken from the same site 4 h after the first biopsy but were unchanged in the second biopsy that was taken from the contralateral site. The biopsies were not associated with changes in plasma and monocyte IL-6 concentrations or in monocyte ER stress markers. Also, whole-body insulin-stimulated glucose uptake was the same in 15 subjects who had biopsies compared with 15 different subjects who did not. Conclusion Open, sc fat biopsies produced inflammation, hypoxia, ER stress, and decreased expression of adiponectin and leptin. These changes remained confined to the biopsy site for at least 4 h.

c-Jun Inhibits Thapsigargin-Induced ER Stress Through Up-Regulation of DSCR1/Adapt78

2008 ◽  
Vol 233 (10) ◽  
pp. 1289-1300 ◽  
Author(s):  
Peng Zhao ◽  
Xiaoyan Xiao ◽  
Agnes S. Kim ◽  
M. Fatima Leite ◽  
Jinxia Xu ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Death ◽  
Er Stress ◽  
Wild Type Mouse ◽  
Mouse Fibroblast ◽  
Expression Levels ◽  
Mouse Fibroblasts ◽  
The Unfolded Protein Response ◽  
Calcineurin Activity

The endoplasmic reticulum (ER) is exquisitely sensitive to changes in its internal environment. Various conditions, collectively termed “ER stress”, can perturb ER function, leading to the activation of a complex response known as the unfolded protein response (UPR). Although c-Jun N-terminal kinase (JNK) activation is nearly always associated with cell death by various stimuli, the functional role of JNK in ER stress-induced cell death remains unclear. JNK regulates gene expression through the phosphorylation and activation of transcription factors, such as c-Jun. Here, we investigated the role of c-Jun in the regulation of ER stress-related genes. c-Jun expression levels determined the response of mouse fibroblasts to ER stress induced by thapsigargin (TG, an inhibitor of sarco/endoplasmic reticulum Ca2+ ATPase). c-jun−/− mouse fibroblast cells were more sensitive to TG-induced cell death compared to wild-type mouse fibroblasts, while reconstitution of c-Jun expression in c-jun−/− cells (c-Jun Re) enhanced resistance to TG-induced cell death. The expression levels of ER chaperones Grp78 and Gadd153 induced by TG were lower in c-Jun Re than in c-jun−/− cells. Moreover, TG treatment significantly increased calcineurin activity in c-jun−/− cells, but not in c-Jun Re cells. In c-Jun Re cells, TG induced the expression of Adapt78, also known as the Down syndrome critical region 1 (DSCR1), which is known to block calcineurin activity. Taken together, our findings suggest that c-Jun, a transcription factor downstream of the JNK signaling pathway, up-regulates Adapt78 expression in response to TG-induced ER stress and contributes to protection against TG-induced cell death.

scholarly journals Maternal high-fat diet induces metabolic stress response disorders in offspring hypothalamus

2017 ◽  
Vol 59 (1) ◽  
pp. 81-92 ◽  
Author(s):  
Long The Nguyen ◽  
Sonia Saad ◽  
Yi Tan ◽  
Carol Pollock ◽  
Hui Chen
Keyword(s):  
Endoplasmic Reticulum ◽  
Body Weight ◽  
Er Stress ◽  
High Fat Diet ◽  
Maternal Obesity ◽  
Mrna Level ◽  
Metabolic Stress ◽  
High Fat ◽  
Chemical Chaperone ◽  
Protein Levels

Maternal obesity has been shown to increase the risk of obesity and related disorders in the offspring, which has been partially attributed to changes of appetite regulators in the offspring hypothalamus. On the other hand, endoplasmic reticulum (ER) stress and autophagy have been implicated in hypothalamic neuropeptide dysregulation, thus may also play important roles in such transgenerational effect. In this study, we show that offspring born to high-fat diet-fed dams showed significantly increased body weight and glucose intolerance, adiposity and plasma triglyceride level at weaning. Hypothalamic mRNA level of the orexigenic neuropeptide Y (NPY) was increased, while the levels of the anorexigenic pro-opiomelanocortin (POMC), NPY1 receptor (NPY1R) and melanocortin-4 receptor (MC4R) were significantly downregulated. In association, the expression of unfolded protein response (UPR) markers including glucose-regulated protein (GRP)94 and endoplasmic reticulum DNA J domain-containing protein (Erdj)4 was reduced. By contrast, protein levels of autophagy-related genes Atg5 and Atg7, as well as mitophagy marker Parkin, were slightly increased. The administration of 4-phenyl butyrate (PBA), a chemical chaperone of protein folding and UPR activator, in the offspring from postnatal day 4 significantly reduced their body weight, fat deposition, which were in association with increased activating transcription factor (ATF)4, immunoglobulin-binding protein (BiP) and Erdj4 mRNA as well as reduced Parkin, PTEN-induced putative kinase (PINK)1 and dynamin-related protein (Drp)1 protein expression levels. These results suggest that hypothalamic ER stress and mitophagy are among the regulatory factors of offspring metabolic changes due to maternal obesity.

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