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

Author(s):  
Ye Zhao ◽  
Ningming Hu ◽  
Qin Jiang ◽  
Li Zhu ◽  
Ming Zhang ◽  
...  

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.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ye Zhao ◽  
Ningming Hu ◽  
Qin Jiang ◽  
Li Zhu ◽  
Ming Zhang ◽  
...  

Abstract Background Rotavirus (RV) is a major pathogen that causes severe gastroenteritis in infants and young animals. Endoplasmic reticulum (ER) stress and subsequent apoptosis play 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), 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) mRNA level, as well as decreased cleaved caspase9 and caspase3 protein levels. Furthermore, siRNA-induced GPR109a knockdown significantly suppressed the protective effect of SB on RV-induced cell apoptosis. Conclusions These results indicate that SB exerts protective effects against RV-induced cell apoptosis through inhibiting ERS mediated apoptosis by regulating PERK-eIF2α signaling pathway via GPR109a, which provide new ideas for the prevention and control of RV.


2020 ◽  
Vol 48 (9) ◽  
pp. 030006052094976
Author(s):  
Min Li ◽  
Ying Zhang ◽  
Jixing Wang

Objective Sepsis-associated encephalopathy (SAE) is a common complication of sepsis, and excessive endoplasmic reticulum (ER) stress is closely correlated with the cell injury caused by sepsis. This study aimed to analyze the possible role of ER stress in SAE cell models. Methods PC12 and MES23.5 cells were treated with increasing concentrations of lipopolysaccharides (LPS). The Cell Counting Kit-8 assay was used to detect cell viability and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was performed to assess cell apoptosis. In addition, the protein expression levels of ER stress markers [GRP78, CHOP, inositol-requiring enzyme 1 (IRE1), and PKR-like ER kinase (PERK)] and apoptosis-related proteins (Bax, Bcl-2, caspase-3, and cleaved caspase-3) were analyzed using western blotting. Results LPS treatment activated ER stress markers in both the PC12 and MES23.5 cells. The overexpression of GRP78 significantly reduced cell viability and enhanced cell apoptosis in a time-dependent manner. An ER stress inhibitor, 4-PBA, significantly enhanced cell viability and inhibited the cell apoptosis induced by LPS. Therefore, an enhanced unfolded protein response (UPR) and UPR suppression may regulate cell apoptosis. Conclusions UPR was shown to be involved in regulating LPS-induced neuron injury. UPR could be a potential therapeutic target in SAE.


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 ◽  
...  

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.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Zhongsheng You ◽  
Linkang He ◽  
Nianlong Yan

Triple negative breast cancer (TNBC) has significantly threatened human health. Many aspects of TNBC are closely related to Wnt/β-catenin pathway, and cell apoptosis induced by endoplasmic reticulum stress (ER stress) in TNBC may act as a potential target of non-chemotherapy treatment. However, how ER stress interacts with this pathway in TNBC has not yet been understood. Here, the tunicamycin and LiCl have been applied to MDA-MB-231. The related proteins’ expression was measured by western blotting. Moreover, acridine orange/ethidium bromide (AO/EB) staining was applied to test the apoptosis degree of the cells, and cell viability was tested by MTT experiment. Then, we found the ER stress and apoptosis degree of MDA-MB-231 were induced after treatment with tunicamycin. Besides, tunicamycin dose dependently inhibited both Wnt/β-catenin pathway and cells viability. Licl, an activator of Wnt/β-catenin signaling pathway, could significantly inhibit cell apoptosis. In conclusion, our study found that the activation of ER stress could promote the MDA-MB-231 apoptosis by repressing Wnt/β-catenin pathway, which provides some promising prospects and basic mechanism to the further research.


Author(s):  
Li Wu ◽  
Yuncheng Lv ◽  
Ying Lv ◽  
Sunmin Xiang ◽  
Zhibo Zhao ◽  
...  

Abstract Excessive accumulation of cholesterol in β cells initiates endoplasmic reticulum (ER) stress and associated apoptosis. We have reported that excessive uptake of cholesterol by MIN6 cells decreases the expression of secretagogin (SCGN) and then attenuates insulin secretion. Here, we aimed to determine whether cholesterol-induced SCGN decrease is involved in the modulation of ER stress and apoptosis in pancreatic β cells. In this study, MIN6 cells were treated with oxidized low-density lipoprotein (ox-LDL) for 24 h, and then intracellular lipid droplets and cell apoptosis were quantified, and SCGN and ER stress markers were identified by western blot analysis. Furthermore, small interfer RNA (siRNA)-mediated SCGN knockdown and recombinant plasmid-mediated SCGN restoration experiments were performed to confirm the role of SCGN in ER stress and associated cell apoptosis. Finally, the interaction of SCGN with ATF4 was computationally predicted and then validated by a co-immunoprecipitation assay. We found that ox-LDL treatment increased the levels of ER stress markers, such as phosphorylated protein kinase-like endoplasmic reticulum kinase, phosphorylated eukaryotic initiation factor 2 alpha, activating transcription factor 4 (ATF4), and transcription factor CCAAT-enhancer-binding protein homologous protein, and promoted MIN6 cell apoptosis; in addition, the expression of SCGN was downregulated. siRNA-mediated SCGN knockdown exacerbated β-cell ER stress by increasing ATF4 expression. Pretreatment of MIN6 cells with the recombinant SCGN partly antagonized ox-LDL-induced ER stress and apoptosis. Furthermore, a co-immunoprecipitation assay revealed an interaction between SCGN and ATF4 in MIN6 cells. Taken together, these results demonstrated that pancreatic β-cell apoptosis induced by ox-LDL treatment can be attributed, in part, to an SCGN/ATF4-dependent ER stress response.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Yanfen Zhou ◽  
Lianyou Zhao ◽  
Zhimin Zhang ◽  
Xuanhao Lu

In the present study, we investigated the effect of methionine-enriched diet (MED) on blood pressure in rats and examined the protective effect of enalapril, a widely used angiotensin converting enzyme inhibitors (ACEi) class antihypertensive drug. The results showed that MED induced significant increase of SBP and Ang II-induced contractile response in aortae of rats. MED significantly increased plasma levels of homocysteine (Hcy) and ACE. In addition, MED increased the phosphorylation of protein kinase R-like endoplasmic reticulum kinase (PERK) and eukaryotic initiation factor 2 (eIF2α) and expression of activating transcription factor 3 (ATF3) and ATF6 in aortae of rats, indicating the occurrence of endoplasmic reticulum (ER) stress. Moreover, MED resulted in oxidative stress as evidenced by significant increase of TBARS level and decrease of superoxide dismutase and catalase activities. Administration of enalapril could effectively inhibit these pathological changes induced by MED in rats. These results demonstrated that ACE-mediated ER stress and oxidative stress played an important role in high Hcy-induced hypertension and MED may exert a positive loop between the activation of ACE and accumulation of Hcy, aggravating the pathological condition of hypertension. The data provide novel insights into the mechanism of high Hcy-associated hypertension and the therapeutic efficiency of enalapril.


2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Feng Liao ◽  
Yang Zheng ◽  
Junyan Cai ◽  
Jinghui Fan ◽  
Jing Wang ◽  
...  

Abstract Catestatin (CST) is a catecholamine secretion inhibiting peptide as non-competitive inhibitor of nicotinic acetylcholine receptor. CST play a protective role in cardiac ischemia/reperfusion (I/R) but the molecular mechanism remains unclear. Cardiomyocytes endogenously produced CST and its expression was reduced after I/R. CST pretreatment decreased apoptosis especially endoplasmic reticulum (ER) stress response during I/R. The protection of CST was confirmed in H9c2 cardiomyoblasts under Anoxia/reoxygenation (A/R). In contrast, siRNA-mediated knockdown of CST exaggerated ER stress induced apoptosis. The protective effects of CST were blocked by extracellular signal-regulated kinases 1/2 (ERK1/2) inhibitor PD90895 and phosphoinositide 3-kinase (PI3 K) inhibitor wortmannin. CST also increased ERK1/2 and protein kinase B (Akt) phosphorylation and which was blocked by atropine and selective type 2 muscarinic acetylcholine (M2) receptor, but not type 1 muscarinic acetylcholine (M1) receptor antagonist. Receptor binding assay revealed that CST competitively bound to the M2 receptor with a 50% inhibitory concentration of 25.7 nM. Accordingly, CST inhibited cellular cAMP stimulated by isoproterenol or forskolin and which was blocked by selective M2 receptor antagonist. Our findings revealed that CST binds to M2 receptor, then activates ERK1/2 and PI3 K/Akt pathway to inhibit ER stress-induced cell apoptosis resulting in attenuation cardiac I/R injury.


2019 ◽  
Vol 20 (23) ◽  
pp. 5846 ◽  
Author(s):  
Fenglei Chen ◽  
Jiaqi Jin ◽  
Jiahui Hu ◽  
Yujing Wang ◽  
Zhiyu Ma ◽  
...  

While silica nanoparticles (SiNPs) have wide applications, they inevitably increase atmospheric particulate matter and human exposure to this nanomaterial. Numerous studies have focused on how to disclose SiNP toxicity and on understanding its toxic mechanisms. However, there are few studies in the literature reporting the interaction between endoplasmic reticulum (ER) stress and SiNP exposure, and the corresponding detailed mechanisms have not been clearly determined. In this study, CCK-8 and flow cytometry assays demonstrated that SiNPs gradually decreased cell viability and increased cell apoptosis in RAW 264.7 macrophage cells in dose- and time-dependent manners. Western blot analysis showed that SiNPs significantly activated ER stress by upregulating GRP78, CHOP, and ERO1α expression. Meanwhile, western blot analysis also showed that SiNPs activated the mitochondrial-mediated apoptotic signaling pathway by upregulating BAD and Caspase-3, and downregulating the BCL-2/BAX ratio. Moreover, 4-phenylbutyrate (4-PBA), an ER stress inhibitor, significantly decreased GRP78, CHOP, and ERO1α expression, and inhibited cell apoptosis in RAW 264.7 macrophage cells. Furthermore, overexpression of CHOP significantly enhanced cell apoptosis, while knockdown of CHOP significantly protected RAW 264.7 macrophage cells from apoptosis induced by SiNPs. We found that the CHOP-ERO1α-caspase-dependent apoptotic signaling pathway was activated by upregulating the downstream target protein ERO1α and caspase-dependent mitochondrial-mediated apoptotic signaling pathway by upregulating Caspase-3 and downregulating the ratio of BCL-2/BAX. In summary, ER stress participated in cell apoptosis induced by SiNPs and CHOP regulated SiNP-induced cell apoptosis, at least partly, via activation of the CHOP-ERO1α-caspase apoptotic signaling pathway in RAW 264.7 macrophage cells.


Animals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3400
Author(s):  
Yan Huang ◽  
Chenxu Zhao ◽  
Yaoquan Liu ◽  
Yezi Kong ◽  
Panpan Tan ◽  
...  

During the perinatal period, the abnormally high plasma non-esterified fatty acids (NEFA) concentration caused by the negative energy balance (NEB) can impose a significant metabolic stress on the liver of dairy cows. Endoplasmic reticulum (ER) stress is an important adaptive response that can serve to maintain cell homeostasis in the event of stress. The protein kinase R-like endoplasmic reticulum kinase (PERK) pathway is the most rapidly activated cascade when ER stress occurs in cells and has an important impact on the regulation of hepatic lipid metabolism and autophagy modulation. However, it is unknown whether NEFA can affect autophagy through modulating the PERK pathway, under NEB conditions. In this study, we provide evidence that NEFA treatment markedly increased lipid accumulation, the phosphorylation level of PERK and eukaryotic initiation factor 2α (eIF2α), and the expression of glucose-regulated protein 78 (Grp78), activating transcription factor 4 (ATF4), and C/EBP homologous protein (CHOP). More importantly, NEFA treatment can cause a substantial increase in the protein levels of autophagy-related gene 7 (ATG7), Beclin-1 (BECN1), sequestosome-1 (p62), and microtubule-associated protein 1 light chain 3 (LC3)-II, and in the number of autophagosomes in primary bovine hepatocytes. The addition of GSK2656157 (PERK phosphorylation inhibitor) can significantly inhibit the effect of NEFA on autophagy and can further increase lipid accumulation. Overall, our results indicate that NEFA could promote autophagy via the PERK pathway in bovine hepatocytes. These findings provide novel evidence about the potential role of the PERK signaling pathway in maintaining bovine hepatocyte homeostasis.


Author(s):  
Xifeng Wang ◽  
Xiaomin Xu ◽  
Yu peng Yang ◽  
Xin Xin ◽  
Zekang Li ◽  
...  

IntroductionThe high mortality of sepsis is closely related to disorder of coagulation induced by endothelial inflammatory response. Our aim is to investigate the protective effects of Dihydromyricetin (DHM) on endothelial cells in sepsis and the endoplasmic reticulum (ER) stress mechanism.Material and methodsIn vivo, we conducted an animal study for which fifty male Wistar rats were randomly and equally divided into five groups: sham group, cecal ligation and puncture (CLP) group and three CLP+ DHM (50, 100, 150 mg/kg) groups, the DHM was orally administered 2 h after CLP for 3 days (once per day). In vitro, human umbilical vein endothelial cells (HUVECs) were treated with DHM (50μmol) for 24 h after stimulation by lipopolysaccharide (LPS). In the inhibition groups, reactive oxygen species (ROS) inhibitor N-acetylcysteine (NAC, 3 mmol) and endoplasmic reticulum (ER) stress inhibitor (STF-083010, 10 μmol) were incubated prior to LPS.ResultsOur results indicated that DHM (150 mg/kg) alleviated the histopathological injury of endothelium, decreased the release of inflammatory cytokines and adhesion molecules such as interleukin-1β (IL-1β), interleukin-6 (IL-6) , tumor necrosis factor alpha (TNF-α), vascular cell adhesion molecule 1 (VCAM-1) and endothelin-1 (ET-1), and inhibited the production of ROS production. In addition, we found that DHM ameliorated ER damage, significantly decreased the protein expressions of IRE1α/NF-κB signaling pathway.ConclusionsDHM treatment alleviated inflammatory response of endothelial cells in sepsis through the IRE1α/NF-κB signaling pathway triggered by oxidative stress. This study provided experimental rationale for the treatment of DHM on therapy of sepsis.


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