scholarly journals The Molecular Mechanism of Endoplasmic Reticulum Stress-Induced Apoptosis in PC-12 Neuronal Cells: The Protective Effect of Insulin-Like Growth Factor I

Endocrinology ◽  
2008 ◽  
Vol 150 (1) ◽  
pp. 277-285 ◽  
Author(s):  
Cheng-Gang Zou ◽  
Xiu-Zhen Cao ◽  
Yue-Shui Zhao ◽  
Shun-Yu Gao ◽  
Shu-De Li ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Protective Effect ◽  
Er Stress ◽  
P38 Mapk ◽  
Neuronal Apoptosis ◽  
Neuronal Cells ◽  
Dependent Manner ◽  
Related Protein ◽  
Igf I ◽  
Induced Apoptosis

Endoplasmic reticulum (ER) stress has been implicated in several neurodegenerative diseases. Although CCAAT/enhancer-binding protein homologous protein (CHOP) has been shown to play a critical role in ER stress, the precise apoptosis cascade downstream of CHOP is unknown. In this report, we investigated the mechanism of ER stress-mediated apoptosis as well as the action of IGF-I in PC-12 neuronal cells. Our results demonstrated that tribbles-related protein 3 (TRB3), which is a target gene of CHOP, was responsible for tunicamycin (an ER stress inducer)-induced apoptosis. TRB3 could promote dephosphorylation of Akt in PC-12 cells. IGF-I inhibited ER stress-induced apoptosis by restoring the phosphorylation level of Akt. Both wortmannin (a phosphatidylinositide 3-kinase inhibitor) and SB 212090 (a p38 MAPK inhibitor) suppressed the protective effect of IGF-I on ER stress-induced apoptosis. Interestingly, IGF-I attenuated ER stress-mediated expression of TRB3 but not CHOP. This action of IGF-I was abolished by SB 212090 but not by wortmannin. Immunoprecipitation analysis revealed that IGF-I promoted the phosphorylation of CHOP by activating p38 MAPK, probably leading to a decrease in the transcriptional activity of CHOP. The dephosphorylation of Akt resulted in increased expression of a proapoptotic protein, p53 up-regulated modulator of apoptosis (PUMA), in a forkhead box O3a-dependent manner. Knockdown of PUMA by short hairpin RNA attenuated ER stress-mediated apoptosis. Thus, our current study indicates that both TRB3 and PUMA are critical molecules in ER stress-induced apoptosis. IGF-I effectively protects PC-12 neuronal cells against ER stress-induced apoptosis through the phosphatidylinositide 3-kinase/Akt and p38 MAPK pathways. Endoplasmic reticulum (ER) stress causes neuronal apoptosis by inducing the expression of tribbles-related protein 3 and PUMA. IGF-1 prevents neuronal apoptosis against ER stress through phosphatidylinositide 3-kinase/Akt and p38 mitogen-activated protein kinase pathways.

Autophagy triggers endoplasmic reticulum stress and C/EBP homologous protein-mediated apoptosis in OGD/R-treated neurons in a caspase-12-independent manner

2021 ◽  
Author(s):  
Ying Tian ◽  
Liang Wang ◽  
Zhiqiang Qiu ◽  
Yulun Xu ◽  
Rongrong Hua
Keyword(s):  
Endoplasmic Reticulum ◽  
Cortical Neurons ◽  
Neuronal Apoptosis ◽  
Glucose Deprivation ◽  
Oxygen Glucose Deprivation ◽  
Caspase 8 ◽  
Dependent Manner ◽  
Homologous Protein ◽  
Caspase 12 ◽  
Induced Apoptosis

We reported that a high level of autophagy was initiated by oxygen-glucose deprivation (OGD) and was maintained in neurons even after oxygen-glucose deprivation followed by reoxygenation (OGD/R), accompanied by neuronal apoptosis. This study focused on autophagy-induced apoptosis and its signaling network, especially the role of endoplasmic reticulum stress (ERS). Analysis of primary cultured cortical neurons from mice showed that the autophagy-induced apoptosis depended on Caspase-8 and -9 but not Caspase-12. This finding did not mean that the endoplasmic reticulum did not participate in this process. Increases in the levels of endoplasmic reticulum (ER) biomarkers and Binding immunoglobulin protein (BiP) were induced by autophagy in OGD/R-treated neurons. In addition, as an apoptotic transcription factor induced by ER stress, C/EBP homologous protein (CHOP) expression was significantly increased in neurons after OGD/R. This result suggested that the autophagy-Bip-CHOP-caspase (8 and 9)-dependent apoptotic signaling pathway at least partly participated in autophagy-induced apoptosis in primary cortical neurons. It revealed that ER induced apoptosis in neurons suffering from OGD/R injury in an ER stress-CHOP-dependent manner rather than a caspase-12-dependent manner. However, more research on signaling or cross-linking networks and intermediate links are needed. The realization of caspase-12-independent BiP-CHOP neuronal apoptosis pathway has expanded our understanding of the neuronal apoptosis network, which may eventually provide endogenous interventional strategies for OGD/R injury after stroke.

Capsaicin mediates apoptosis in human nasopharyngeal carcinoma NPC-TW 039 cells through mitochondrial depolarization and endoplasmic reticulum stress

2011 ◽  
Vol 31 (6) ◽  
pp. 539-549 ◽  
Author(s):  
S-W Ip ◽  
S-H Lan ◽  
H-F Lu ◽  
A-C Huang ◽  
J-S Yang ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Death ◽  
Nasopharyngeal Carcinoma ◽  
Er Stress ◽  
Molecular Mechanisms ◽  
Human Cancer ◽  
Dependent Manner ◽  
Mitochondrial Depolarization ◽  
Human Nasopharyngeal Carcinoma ◽  
Induced Apoptosis

Capsaicin, a pungent compound found in hot chili peppers, has been reported to have antitumor activities in many human cancer cell lines, but the induction of precise apoptosis signaling pathway in human nasopharyngeal carcinoma (NPC) cells is unclear. Here, we investigated the molecular mechanisms of capsaicin-induced apoptosis in human NPC, NPC-TW 039, cells. Effects of capsaicin involved endoplasmic reticulum (ER) stress, caspase-3 activation and mitochondrial depolarization. Capsaicin-induced cytotoxic effects (cell death) through G0/G1 phase arrest and induction of apoptosis of NPC-TW 039 cells in a dose-dependent manner. Capsaicin treatment triggered ER stress by promoting the production of reactive oxygen species (ROS), increasing levels of inositol-requiring 1 enzyme (IRE1), growth arrest and DNA-damage-inducible 153 (GADD153) and glucose-regulated protein 78 (GRP78). Other effects included an increase in cytosolic Ca2+, loss of the mitochondrial transmembrane potential (ΔΨ m), releases of cytochrome c and apoptosis-inducing factor (AIF), and activation of caspase-9 and -3. Furthermore, capsaicin induced increases in the ratio of Bax/Bcl-2 and abundance of apoptosis-related protein levels. These results suggest that ER stress- and mitochondria-mediated cell death is involved in capsaicin-induced apoptosis in NPC-TW 039 cells.

scholarly journals Protective Effects of Sodium Butyrate on Rotavirus Inducing Endoplasmic Reticulum Stress-Mediated Apoptosis Via PERK-eIF2α Signaling Pathway in IPEC-J2 Cells

2020 ◽  
Author(s):  
Ye Zhao ◽  
Ningming Hu ◽  
Qin Jiang ◽  
Li Zhu ◽  
Ming Zhang ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Protective Effect ◽  
Er Stress ◽  
Signaling Pathway ◽  
Sodium Butyrate ◽  
Cell Apoptosis ◽  
Initiation Factor ◽  
Intestinal Damage ◽  
Dependent Manner ◽  
Protective Effects

Abstract Background: Rotavirus (RV) is an important pathogens that causes severe gastroenteritis in infants and young animals. Endoplasmic reticulum (ER) stress and subsequent apoptosis played pivotal role in virus infection. However, the protective mechanisms of intestinal damage caused by RV are poorly defined, especially the molecular pathways related to enterocytes apoptosis. Thus, the aim of this study was to investigate the protective effect and mechanism of sodium butyrate (SB) on RV-induced apoptosis of IPEC-J2 cells. Results: The RV infection led to significant cell apoptosis, increased the expression levels of ER stress (ERS) markers, phosphorylated protein kinase-like ER kinase (PERK), phosphorylated eukaryotic initiation factor 2 alpha (eIF2α), caspase9, and caspase3. Blocking PERK pathway using specific inhibitor GSK subsequently reversed RV-induced cell apoptosis. The SB treatment significantly inhibited RV-induced ERS by decreasing the expression of glucose regulated protein 78 (GRP78), PERK, and eIF2α. In addition, SB treatment restrained the ERS-mediated apoptotic pathway, as indicated by downregulation of C/EBP homologous protein (CHOP), as well as decreased cleaved caspase 9 and 3. Furthermore, siRNA-induced GPR109a knockdown significantly suppressed the protective effect of SB on RV-induced cell apoptosis. Conclusion: Taken together, these findings revealed that SB exerts protective effects against RV-induced cell apoptosis through inhibiting ERS mediated apoptosis via PERK-eIF2α signaling pathway in a GPR109a-dependent manner, which provide new ideas for the prevention and control of RV.

scholarly journals Endoplasmic Reticulum Stress-Induced Resistance to Doxorubicin Is Reversed by Mulberry Leaf Polyphenol Extract in Hepatocellular Carcinoma through Inhibition of COX-2

Antioxidants ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 26 ◽  
Author(s):  
Mon-Yuan Yang ◽  
Cheng-Hsun Wu ◽  
Tung-Wei Hung ◽  
Chau-Jong Wang
Keyword(s):  
Hepatocellular Carcinoma ◽  
Endoplasmic Reticulum ◽  
Er Stress ◽  
P38 Mapk ◽  
Induced Resistance ◽  
Anticancer Properties ◽  
Mulberry Leaf ◽  
Cox 2 ◽  
P38 Mapk Inhibitor ◽  
Induced Apoptosis

Mulberry (Morus alba L.) leaves are used in Chinese medicine to treat metabolic disorders. Mulberry leaf polyphenol extracts (MLPE) have recently been shown to exhibit anticancer properties. Endoplasmic reticulum (ER) stress represents a pivotal obstacle in solid tumors, resulting in the antiapoptosis of tumor cells and drug resistance. In this study, pretreatment with the ER stress inducer tunicamycin (TM) attenuated the percentage of apoptosis induced by doxorubicin (DOX). Cotreatment with tunicamycin and MLPE reversed apoptosis induced by DOX. Simultaneously, induction of ER stress with tunicamycin resulted in an increased expression of Cyclooxygenase 2 (COX-2) and Glucose-regulated protein (GRP78) concomitant with the activation of p38 MAPK/PI3K/Akt in HepG2 cells. Furthermore, the suppression of ER stress with celecoxib or p38 MAPK inhibitor successfully recovered DOX-induced apoptosis. Consistent with the inhibition of COX-2 or p38 MAPK, copretreatment with TM and MLPE drastically recovered cytotoxicity and caspase-3 activation in the presence of DOX. These results reveal that MLPE reduces ER stress-induced resistance to DOX in hepatocellular carcinoma (HCC) cells through downregulation of COX-2- or p38 MAPK-mediated PI3K/Akt pathway.

scholarly journals FBXO6-Mediated Ubiquitination and Degradation of Ero1L Inhibits Endoplasmic Reticulum Stress-Induced Apoptosis

2016 ◽  
Vol 39 (6) ◽  
pp. 2501-2508 ◽  
Author(s):  
Xi Chen ◽  
Lang-Huan Duan ◽  
Peng-cheng Luo ◽  
Gang Hu ◽  
Xin Yu ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Critical Role ◽  
Dependent Manner ◽  
Ubiquitin E3 Ligase ◽  
The Stability ◽  
Induced Apoptosis ◽  
F Box Protein ◽  
Protein Disulfide

Background/Aims: FBXO6 is the substrate recognition component of a Skp1-Cullin1-F-box protein (SCF) ubiquitin E3 ligase complex, recognizing the chitobiose in unfolded N-glycoprotein to target glycoproteins for polyubiquitination and degradation. Although how FBXO6 recognizes glycoprotein has been fully investigated, the ubiquitination substrates of FBXO6 remain largely unknown. Previously, we have systematically identified the glycoproteins that interact with FBXO6 in an N-glycan dependent manner by LC/MS spectrum and confirmed the interaction between FBXO6 and glycosylated Ero1L, a protein disulfide oxidase in endoplasmic reticulum (ER). Methods: The relationship between endogenous Ero1L and exogenous Flag-FBXO6 were determined by Western blot. In vivo ubiquitination assay was used to detect the direct effect of FBXO6 in the regulation of Ero1L. Both CCK8 and FACS assays were used to determine the apoptosis ratio of cells after treatments. Results: Ero1L is a ubiquitination substrate of FBXO6. FBXO6 mediates the degradation of Ero1L through a ubiquitylation-dependent pathway. Overexpression of FBXO6 increased the polyubiquitination and decreased the stability of Ero1L, whereas inhibition of FBXO6 prolonged the half-life of Ero1L. Functionally, we show that FBXO6 inhibits ER stress-induced apoptosis by modulating the protein level of Ero1L. Conclusion: Collectively, our results demonstrate FBXO6 as a functional E3 ubiquitin ligase for Ero1L that plays a critical role in inhibiting ER stress-induced apoptosis.

scholarly journals Acetaldehyde Induces Neurotoxicity In Vitro via Oxidative Stress- and Ca2+ Imbalance-Mediated Endoplasmic Reticulum Stress

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Jiahui Cui ◽  
Yang Liu ◽  
Xing Chang ◽  
Wenfeng Gou ◽  
Xuejiao Zhou ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Early Stage ◽  
Neuronal Cells ◽  
Toxic Metabolite ◽  
Related Protein ◽  
Ht22 Cells ◽  
Induced Apoptosis

Excessive drinking can damage brain tissue and cause cognitive dysfunction. Studies have found that the early stage of neurodegenerative disease is closely related to heavy drinking. Acetaldehyde (ADE) is the main toxic metabolite of alcohol. However, the exact mechanisms of ADE-induced neurotoxicity are not fully clear. In this article, we studied the cytotoxic effect of ADE in HT22 cells and primary cultured cortical neuronal cells. We found that ADE exhibited cytotoxicities against HT22 cells and primary cultured cortical neuronal cells in dose-dependent manners. Furthermore, ADE induced apoptosis of HT22 cells by upregulating the expression of caspase family proapoptotic proteins. Moreover, ADE treatment could significantly increase the intracellular Ca2+ and reactive oxygen species (ROS) levels and activate endoplasmic reticulum stress (ERS) in HT22 cells. ADE upregulated ERS-related CHOP expression dose-dependently in primary cultured cortical neuronal cells. In addition, inhibition of ROS with antioxidant N-acetyl-L-cysteine (NAC) reduced the accumulation of ROS and reversed ADE-induced increase of ERS-related protein and apoptosis-related protein levels. Mitigation of ERS with ERS inhibitor 4-PBA obviously suppressed ADE-induced apoptosis and the expression of ERS-related proteins. Therefore, ADE induces neurotoxicity of HT22 cells via oxidative stress- and Ca2+ imbalance-mediated ERS.

scholarly journals Human Immunodeficiency Virus Type 1 Vpr Induces Apoptosis in Human Neuronal Cells

2000 ◽  
Vol 74 (20) ◽  
pp. 9717-9726 ◽  
Author(s):  
Charvi A. Patel ◽  
Muhammad Mukhtar ◽  
Roger J. Pomerantz
Keyword(s):  
Cell Line ◽  
Neuronal Apoptosis ◽  
Neuronal Cells ◽  
Caspase 8 ◽  
Dependent Manner ◽  
Human Neurons ◽  
Induced Apoptosis ◽  
Human Neuronal Cells ◽  
Nt2 Cells ◽  
Hiv 1

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) infection of the central nervous system (CNS) causes AIDS dementia complex (ADC) in certain infected individuals. Recent studies have suggested that patients with ADC have an increased incidence of neuronal apoptosis leading to neuronal dropout. Of note, a higher level of the HIV-1 accessory protein Vpr has been detected in the cerebrospinal fluid of AIDS patients with neurological disorders. Moreover, extracellular Vpr has been shown to form ion channels, leading to cell death of cultured rat hippocampal neurons. Based on these previous findings, we first investigated the apoptotic effects of the HIV-1 Vpr protein on the human neuronal precursor NT2 cell line at a range of concentrations. These studies demonstrated that apoptosis induced by both Vpr and the envelope glycoprotein, gp120, occurred in a dose-dependent manner compared to protein treatment with HIV-1 integrase, maltose binding protein (MBP), and MBP-Vpr in the undifferentiated NT2 cells. For mature, differentiated neurons, apoptosis was also induced in a dose-dependent manner by both Vpr and gp120 at concentrations ranging from 1 to 100 ng/ml, as demonstrated by both the terminal deoxynucleotidyltransferase (Tdt)-mediated dUTP-biotin nick end labeling and Annexin V assays for apoptotic cell death. In order to clarify the intracellular pathways and molecular mechanisms involved in Vpr- and gp120-induced apoptosis in the NT2 cell line and differentiated mature human neurons, we then examined the cellular lysates for caspase-8 activity in these studies. Vpr and gp120 treatments exhibited a potent increase in activation of caspase-8 in both mature neurons and undifferentiated NT2 cells. This suggests that Vpr may be exerting selective cytotoxicity in a neuronal precursor cell line and in mature human neurons through the activation of caspase-8. These data represent a characterization of Vpr-induced apoptosis in human neuronal cells, and suggest that extracellular Vpr, along with other lentiviral proteins, may increase neuronal apoptosis in the CNS. Also, identification of the intracellular activation of caspase-8 in Vpr-induced apoptosis of human neuronal cells may lead to therapeutic approaches which can be used to combat HIV-1-induced neuronal apoptosis in AIDS patients with ADC.

scholarly journals Nicorandil Protects the Heart from Ischemia/Reperfusion Injury by Attenuating Endoplasmic Reticulum Response-induced Apoptosis Through PI3K/Akt Signaling Pathway

2015 ◽  
Vol 35 (6) ◽  
pp. 2320-2332 ◽  
Author(s):  
Hui Wu ◽  
Ming Ye ◽  
Jun Yang ◽  
Jiawang Ding ◽  
Jian Yang ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Infarct Size ◽  
Er Stress ◽  
Ischemia Reperfusion ◽  
Pi3k Inhibitor ◽  
Myocardial Infarct Size ◽  
Dependent Manner ◽  
Phosphatidylinositol 3 Kinase ◽  
Induced Apoptosis ◽  
Phosphatidylinositol 3

Background/Aims: As a vasodilatory drug used to treat angina, nicorandil has been shown to induce an infarct-limiting effect in various experimental animal models of myocardial ischemia-reperfusion (IR). There are multiple mechanisms causing the IR injury, among which, the endoplasmic reticulum (ER) stress and ER stress-initiated apoptosis are implicated to play an important role. However, whether ER stress is involved in nicorandil-induced cardioprotection is unknown. Methods: Post-ischemic functional recovery, lactate dehydrogenase (LDH) release and infarct size in perfused rat hearts subjected to global no-flow I/R were measured to analysis the effect of nicorandil and ER stress inducer of tunicamycin as well as phosphatidylinositol 3-kinase (PI3K) inhibitor of wortmannin on the I/R hearts. The I/R hearts tissue were harvested to evaluate apoptosis ratio with TUNEL assay and protein expression with western blot. Results: We showed that nicorandil ameliorated postischemic contractile recovery, as well as significantly reduced myocardial infarct size at a dose-dependent manner. Furthermore, nicorandil treatment inhibited the IR-induced apoptosis and ER stress. The beneficial effects of nicorandil were blocked by ER stress inducer, tunicamycin and specific phosphatidylinositol 3-kinase (PI3K) inhibitor, wortmannin. Concolusion: We conclude that the cardioprotection of nicorandil was at least in part mediated via inhibition of ER stress-induced apoptotic cell death through PI3K/Akt pathway.

Testicular Injury Attenuated by Rapamycin Through Induction of Autophagy and Inhibition of Endoplasmic Reticulum Stress in Streptozotocin- Induced Diabetic Rats

2019 ◽  
Vol 19 (5) ◽  
pp. 665-675 ◽  
Author(s):  
Wenjiao Shi ◽  
Zhixin Guo ◽  
Ruixia Yuan
Keyword(s):  
Oxidative Stress ◽  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Protective Effect ◽  
Er Stress ◽  
B Cell Lymphoma ◽  
Diabetic Rats ◽  
Pathological Changes ◽  
Rapamycin Treatment ◽  
Related Proteins

Background and Objective: This study investigated whether rapamycin has a protective effect on the testis of diabetic rats by regulating autophagy, endoplasmic reticulum stress, and oxidative stress. Methods: Thirty male Sprague-Dawley rats were randomly divided into three groups: control, diabetic, and diabetic treated with rapamycin, which received gavage of rapamycin (2mg.kg-1.d-1) after induction of diabetes. Diabetic rats were induced by intraperitoneal injection of streptozotocin (STZ, 65mg.Kg-1). All rats were sacrificed at the termination after 8 weeks of rapamycin treatment. The testicular pathological changes were determined by hematoxylin and eosin staining. The protein or mRNA expression of autophagy-related proteins (Beclin1, microtubule-associated protein light chain 3 (LC3), p62), ER stress marked proteins (CCAAT/enhancer-binding protein (C/EBP) homologous protein (CHOP), caspase-12), oxidative stress-related proteins (p22phox, nuclear factor erythroid2-related factor 2 (Nrf2)) and apoptosis-related proteins (Bax, B cell lymphoma-2 (Bcl-2)) were assayed by western blot or real-time fluorescence quantitative PCR. Results: There were significant pathological changes in the testes of diabetic rats. The expression of Beclin1, LC3, Nrf2, Bcl-2 were significantly decreased and p62, CHOP, caspase12, p22phox, and Bax were notably increased in the testis of diabetic rats (P <0.05). However, rapamycin treatment for 8 weeks significantly reversed the above changes in the testis of diabetic rats (P <0.05). Conclusion: Rapamycin appears to produce a protective effect on the testes of diabetic rats by inducing the expression of autophagy and inhibiting the expression of ER-stress, oxidative stress, and apoptosis.

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