Objective Autophagy is a highly conserved intracellular degradation pathway. Many picornaviruses induce autophagy to benefit viral replication, but an understanding of how autophagy occurs remains incomplete. In this ...Objective Autophagy is a highly conserved intracellular degradation pathway. Many picornaviruses induce autophagy to benefit viral replication, but an understanding of how autophagy occurs remains incomplete. In this study, we explored whether coxsackievirus B3(CVB3) infection induced autophagy through endoplasmic reticulum(ER) stress. Methods In CVB3-infected HeLa cells, the specific molecules of ER stress and autophagy were detected using Western blotting, reverse transcription polymerase chain reaction(RT-PCR), and confocal microscopy. Then PKR-like ER protein kinase(PERK) inhibitor, inositol-requiring protein-1(IRE1) inhibitor, or activating transcription factor-6(ATF6) inhibitor worked on CVB3-infected cells, their effect on autophagy was assessed by Western blotting for detecting microtubule-associated protein light chain 3(LC3). Results CVB3 infection induced ER stress, and ER stress sensors PERK/eIF2α, IRE1/XBP1, and ATF6 were activated. CVB3 infection increased the accumulation of green fluorescent protein(GFP)-LC3 punctuation and induced the conversion from LC3-Ⅰ to phosphatidylethanolamine-conjugated LC3-1(LC3-Ⅱ). CVB3 infection still decreased the expression of mammalian target of rapamycin(mTOR) and p-mTOR. Inhibition of PERK, IRE1, or ATF6 significantly decreased the ratio of LC3-Ⅱ to LC3-Ⅰ in CVB3-infected HeLa cells. Conclusion CVB3 infection induced autophagy through ER stress in HeL a cells, and PERK, IRE1, and ATF6 a pathways participated in the regulation of autophagy. Our data suggested that ER stress may inhibit mTOR signaling pathway to induce autophagy during CVB3 infection.展开更多
The well-known insulin-like growth factor 1(IGF1)/IGF-1 receptor(IGF-1R)signaling pathway is overexpressed in many tumors,and is thus an attractive target for cancer treatment.However,results have often been disappoin...The well-known insulin-like growth factor 1(IGF1)/IGF-1 receptor(IGF-1R)signaling pathway is overexpressed in many tumors,and is thus an attractive target for cancer treatment.However,results have often been disappointing due to crosstalk with other signals.Here,we report that IGF-1R signaling stimulates the growth of hepatocellular carcinoma(HCC)cells through the translocation of IGF-1R into the ER to enhance sarco-endoplasmic reticulum calcium ATPase 2(SERCA2)activity.In response to ligand binding,IGF-1Rβis translocated into the ER byβ-arrestin2(β-arr2).Mass spectrometry analysis identified SERCA2 as a target of ER IGF-1Rβ.SERCA2 activity is heavily dependent on the increase in ER IGF-1Rβlevels.ER IGF-1Rβphosphorylates SERCA2 on Tyr^(990)to enhance its activity.Mutation of SERCA2-Tyr^(990)disrupted the interaction of ER IGF-1Rβwith SERCA2,and therefore ER IGF-1Rβfailed to promote SERCA2 activity.The enhancement of SERCA2 activity triggered Ca_(ER)^(2+)perturbation,leading to an increase in autophagy.Thapsigargin blocked the interaction between SERCA2and ER IGF-1Rβand therefore SERCA2 activity,resulting in inhibition of HCC growth.In conclusion,the translocation of IGF-1R into the ER triggers Ca_(ER)^(2+)perturbation by enhancing SERCA2 activity through phosphorylating Tyr^(990)in HCC.展开更多
Efficient functioning of the endoplasmic reticulum(ER) is very important for most cellular activities, such as protein folding and modification. The ER closely interacts with other organelles, including the Golgi body...Efficient functioning of the endoplasmic reticulum(ER) is very important for most cellular activities, such as protein folding and modification. The ER closely interacts with other organelles, including the Golgi body, endosome, membrane, and mitochondria, providing lipids and proteins for the repair of these organelles. ER stress can be induced by various abnormal materials in the cell. ER stress is a compensatory intracellular environment disorder that occurs during areaction. ER can sense the stress and respond to it through translational attenuation, upregulation of the genes for ER chaperones and related proteins, and degradation of unfolded proteins by a quality-control system, but excessive ER activation can cause cell death. The Pubmed and Web of Science databases were searched for full-text articles, and the terms "endoplasmic reticulum stress/unfolded protein response/gynecologic tumor cell apoptosis" were used as key words. Thirty-five studies of ER stress and unfolded protein response published from 2000 to 2016 were analyzed. Stress triggers apoptosis through a variety of signaling pathways. Increasing evidence has shown that the ER plays an important role in tumor cell diseases. The present review discusses the molecular mechanisms underlying unfolded protein response and its ability to promote survival and proliferation in gynecologic tumor cells.展开更多
Objective:To examine whether exposure of mouse neuronal cells to radiofrequency fields used in mobile communication devices can induce stress in endoplasmic reticulum(ER)and activate unfolded protein response(UPR).Met...Objective:To examine whether exposure of mouse neuronal cells to radiofrequency fields used in mobile communication devices can induce stress in endoplasmic reticulum(ER)and activate unfolded protein response(UPR).Methods:HT22 mouse hippocampus neuronal cells were exposed to continuous wave 900 MHz radiofrequency fields(RF)at 120μW/cm2 power intensity for 4 h/d for 5 consecutive days.The positive control cells were irradiated with 4 Gy of 60Coγ-rays at a dose rate of 0.5 Gy/min(GR).Twenty-four hours after the last exposure,cells were collected,and the expressions of sensor transmembrane proteins were detected using Western blot analysis.Results:The expression levels of Ire1,PERK,p-IRE1 and p-PERK,GRP78 and CHOP proteins were detected.There were no statistically significant differences in the expression levels of IRE1 and PERK proteins in control(CT),sham(SH)-,RF-and GR-exposed cells(P<0.05).The phosphorylated protein levels of p-IRE1 and p-PERK were significantly increased in cells exposed to RF and GR(P<0.05).The expression levels of GRP78 and CHOP were significantly increased in RF-and GR-exposed cells compared to CT and SH-exposed cells(P<0.05).Cells treated with 1μg/ml TM for 24 h showed significantly increased expression levels of GRP78 and CHOP proteins compared to controls(P<0.05).In the presence of 2 mmol/L PBA,TM-induced increased levels of GRP78 and CHOP proteins were reduced(P<0.05).Conclusions:The exposure of non-ionizing 900 MHz RF was able to cause stress in HT22 mouse neuronal cells and activated UPR in ER.Since UPR plays an important role in both cell survival(when UPR is mitigated)and apoptosis/death(under unresolvable stress conditions),further studies are required to determine the fate of the cells exposed to RF.展开更多
Abstract The unfolded protein response(UPR)is an important protective and compensatory strategy used during endoplasmic reticulum stress caused by factors including glucose starvation,low pH,or heat shock.However,ther...Abstract The unfolded protein response(UPR)is an important protective and compensatory strategy used during endoplasmic reticulum stress caused by factors including glucose starvation,low pH,or heat shock.However,there is very little information on the possible role(s)of the UPR under adverse conditions experienced by marine invertebrates.We observed that rough endoplasmic reticulum(ER)was dramatically expanded and numerous autophagosomes were accumulated in the intestinal cells of sea cucumbers,Apostichopus japonicus,under heat stress(4 h at 25°C compared with 15°C controls).Moreover,heat stress led to sharp increases in the relative transcript and protein expression levels of two primary ER chaperones:the endoplasmic reticulum resident protein 29-like(ERP29)and protein disulfi de-isomerase A6-like(PDIA6).These results suggest a potential adaptive mechanism to deal with heat-induced stress in sea cucumber intestine.展开更多
Objective： The aim of this study was to explore the mechanisms by which the flavonoid casticin enhances tumor necrosis factor-related apoptosis-inducing ligand （TRAIL）-induced apoptosis in colon cancer cells. Meth...Objective： The aim of this study was to explore the mechanisms by which the flavonoid casticin enhances tumor necrosis factor-related apoptosis-inducing ligand （TRAIL）-induced apoptosis in colon cancer cells. Methods： Human colon cancer HT-29 cells were treated with TRAIL or casticin. Cytotoxicity was examined by MTT assay, and apoptosis determined by morphological observation and flow cytometric analysis. Death receptor 5 （DRS）, DR4, and endoplasmic reticulum （ER） stress response markers, including glucose regulating protein 78 （GRP78）, activating transcription factor 4 （ATF4） and CHOP （CCAAT/enhancer binding protein homologous protein）, were examined with western blot. Small interfering RNA （siRNA） transfection was employed to knock down CHOP. Results： HT-29 cells were resistance to TRAIL-induced apoptosis, but casticin, at subtoxic concentrations, potentiated HT-29 cells to TRAIL-induced apoptosis. Casticin up-regulated the expression of DR5 time-and dose-dependent manners, but had no effect on the expression of DR4. Also, casticin increased the levels of ER stress response markers （GRP78, ATF4 and CHOP） in a similar way to DR5. Knockdown of CHOP by specific siRNA, or salubrinal, an ER stress inhibitor, abolished the up-regulation of DR5 and enhancement of TRAIL-induced apoptosis by casticin. Conclusion： Casticin enhances TRAIL-induced apoptosis of colon cancer cells by ER stress-mediated up-regulation of DR5.展开更多
Golgi apparatus,together with endoplasmic reticula,vacuoles and plasma membrane,constitutes the endoplasmic system of plant cells.It plays an important role in the secretion pathway of eukaryotic cells and is responsi...Golgi apparatus,together with endoplasmic reticula,vacuoles and plasma membrane,constitutes the endoplasmic system of plant cells.It plays an important role in the secretion pathway of eukaryotic cells and is responsible for various intracellular events,such as protein classification,protein modification and glycosylation.At present,much less is known about plant Golgi proteins.The research on its function is still insufficient.In order to provide a comprehensive research background and research ideas for related researchers,this paper systematically and comprehensively evaluated the structure of plant endoplasmic system,the common endoplasmic reticulum-Golgi transport pathway in plant cells,various possible transport models between endoplasmic reticula and Golgi bodies,Golgi-associated specific proteins and functions,and Golgi biogenesis pathway.The latest research progress in this field was reviewed and analyzed in detail.This paper will provide an important reference for related researchers to carry out the research of plant Golgi.展开更多
Endoplasmic reticulum(ER)stress occurs when ER homeostasis is perturbed with accumulation of unfolded/misfolded protein or calcium depletion.The unfolded protein response(UPR),comprising of inositol-requiring enzyme 1...Endoplasmic reticulum(ER)stress occurs when ER homeostasis is perturbed with accumulation of unfolded/misfolded protein or calcium depletion.The unfolded protein response(UPR),comprising of inositol-requiring enzyme 1 a(IRE1 a),double-stranded RNA-dependent protein kinase(PKR)-like ER kinase(PERK)and activating transcription factor 6(ATF6)signaling pathways,is a protective cellular response activated by ER stress.However,UPR activation can also induce cell death upon persistent ER stress.The liver is susceptible to ER stress given its synthetic and other biological functions.Numerous studies from human liver samples and animal disease models have indicated a crucial role of ER stress and the UPR signaling pathways in the pathogenesis of liver diseases,including non-alcoholic fatty liver disease(NAFLD),alcoholic liver disease(ALD),alpha-1 antitrypsin(AAT)deficiency(AATD),cholestatic liver disease,drug-induced liver injury,ischemia/reperfusion(I/R)injury,viral hepatitis and hepatocel-lular carcinoma(HCC).Extensive investigations have demonstrated the potential underlying mechanisms of the induction of ER stress and the contribution of the UPR pathways during the development of the diseases.Moreover,ER stress and the UPR proteins and genes have become emerging therapeutic targets to treat liver diseases.展开更多
Endoplasmic reticulum(ER)stress,as an emerging hallmark feature of cancer,has a considerable impact on cell proliferation,metastasis,invasion,and chemotherapy resistance.Ovarian cancer(OvCa)is one of the leading cause...Endoplasmic reticulum(ER)stress,as an emerging hallmark feature of cancer,has a considerable impact on cell proliferation,metastasis,invasion,and chemotherapy resistance.Ovarian cancer(OvCa)is one of the leading causes of cancer-related mortality across the world due to the late stage of disease at diagnosis.Studies have explored the influence of ER stress on OvCa in recent years,while the predictive role of ER stress-related genes in OvCa prognosis remains unexplored.Here,we enrolled 552 cases of ER stress-related genes involved in OvCa from The Cancer Genome Atlas(TCGA)and Gene Expression Omnibus(GEO)cohorts for the screening of prognosis-related genes.The least absolute shrinkage and selection operator(LASSO)regression was applied to establish an ER stress-related risk signature based on the TCGA cohort.A seven-gene signature revealed a favorable predictive efficacy for the TCGA,International Cancer Genome Consortium(ICGC),and another GEO cohort(P<0.001,P<0.001,and P=0.04,respectively).Moreover,functional annotation indicated that this signature was enriched in cellular response and senescence,cytokines interaction,as well as multiple immune-associated terms.The immune infiltration profiles further delineated an immunologic unresponsive status in the high-risk group.In conclusion,ER stress-related genes are vital factors predicting the prognosis of OvCa,and possess great application potential in the clinic.展开更多
This study aimed to elucidate the molecular mechanisms by which berberine protects against cerebral ischemia/reperfusion(I/R)injury.The oxygen-glucose deprivation/reperfusion(OGD/R)PC12 model was established.Cell coun...This study aimed to elucidate the molecular mechanisms by which berberine protects against cerebral ischemia/reperfusion(I/R)injury.The oxygen-glucose deprivation/reperfusion(OGD/R)PC12 model was established.Cell counting kit-8(CCK-8)was used to detect the toxicity of berberine and the viability of PC12 cells.Hoechst 33258 staining and flow cytometry were used to observe the nuclear morphology,and changes of apoptosis and reactive oxygen species(ROS),respectively.Western blotting and immunofluorescence assay were employed to detect autophagy-related proteins[microtubule-associated protein 1A/1B-light chain 3(LC3),P62/SQSTM-1,Beclin-1]and endoplasmic reticulum(ER)stress-related markers[glucose-regulated protein 78(GRP78),C/EBP homologous protein(CHOP),Bcl-2-associated X(Bax)and cleaved caspase-3].The GFP-RFP-LC3 adenovirus was used to assay the change of autophagic flux.Our results showed that berberine could increase the viability of PC12 cells,decrease the concentrations of ROS after OGD/R treatment,and suppress OGD/R-induced ER stress and autophagy.Moreover,the results revealed the involvement of the mammalian target of rapamycin(mTOR)pathway in the induction of autophagy,and berberine could activate the phosphorylation of mTOR and thus mitigate autophagy.In conclusion,our study suggested that berberine may protect against OGD/R-induced apoptosis by regulating ER stress and autophagy,and it holds promises in the treatment of cerebral I/R injury.展开更多
Autophagy is a self-eating process,in which the damaged or excessed cell organelles and misfolded protein aggregates are removed from the cellular microenvironment.Autophagy is generally thought of as a pro-survival m...Autophagy is a self-eating process,in which the damaged or excessed cell organelles and misfolded protein aggregates are removed from the cellular microenvironment.Autophagy is generally thought of as a pro-survival mechanism which is not only important for balancing energy supply at times of nutrient deprivation but also in the removal of various stress stimuli to ensure homeostasis.In addition to the target materials of“self”origin,autophagy can also eliminate intracellular pathogens and acts as a defense mechanism to curb infections.In addition,autophagy is linked to the host cell's innate immune response.However,viruses have evolved various strategies to manipulate and overtake host cell machinery to establish productive replication and maintain infectious process.In fact,replication of many viruses has been found to be autophagy-dependent and suppression of autophagy can potentially affect the viral replication.Thus,autophagy can either serve as an anti-viral defense mechanism or a pro-viral process that supports viral replication.Hepatitis B virus(HBV)and hepatitis C virus(HCV)are known to co-opt cellular autophagy process as a pro-viral tool.Both viruses also induce mitophagy,which contributes to the establishment of chronic hepatitis.This review focuses on the roles of autophagy and mitophagy in the chronic liver disease pathogenesis associated with HBV and HCV infections.展开更多
The endoplasmic reticulum(ER)is an intracellular organelle consisting of a continuous network of membranes.In the liver,the ER is highly active in protein modification,lipid metabolism,and xenobiotic detoxification.Ma...The endoplasmic reticulum(ER)is an intracellular organelle consisting of a continuous network of membranes.In the liver,the ER is highly active in protein modification,lipid metabolism,and xenobiotic detoxification.Maintaining these complicated processes requires elaborate control of the ER lumen environment as well as the ER volume.Increasing evidence suggests that autophagy plays a critical role in regulating the homeostasis of hepatic ER contents and levels of cytochrome P450(CYP)enzymes via selective ER-phagy.This review will provide an overview of ER-phagy,summarizing the possible roles of recently identified ER-phagy receptor proteins in regulating the homeostasis of hepatic ER and CYP enzymes as well as outlining the various implications of ER-phagy in ER-related liver diseases.展开更多
Sangguayin preparation(SGY-P) is refined from the traditional Chinese medicinal compound Sangguayin, which"clears heat and promotes fluid" and "tonifies kidney and spleen" for "Xiaoke", c...Sangguayin preparation(SGY-P) is refined from the traditional Chinese medicinal compound Sangguayin, which"clears heat and promotes fluid" and "tonifies kidney and spleen" for "Xiaoke", commonly known as ‘Diabetes mellitus’ in clinics.Previous studies have shown that SGY-P could reduce insulin resistance and repair damaged pancreas in db/db mice, but the underlying mechanisms were unclear. Here, we investigated whether treatment with SGY-P could protect pancreatic β-cells from apoptosis and uncovered the underlying mechanisms. db/db mice were used to observe the hypoglycemic and islet protective effect in vivo. Apoptosis was induced in mouse insulinoma 6(MIN6) cells by palmitate, following which the cells were treated with SGY-P for elucidating the anti-apoptotic mechanism in vitro. Cell viability and nuclear morphology were detected by CCK-8 assay and Hoechst 33258 staining. The expression levels of apoptosis-, endoplasmic reticulum(ER) stress-, and autophagy-related proteins were measured by western blot. The results showed that SGY-P reduced fasting blood glucose, pancreatic pathological changes, and islet β-cell apoptosis in db/db mice. Palmitate-induced apoptosis in MIN6 cells was decreased by SGY-P treatment. Hence, SGY-P therapy exhibited a protective effect on pancreatic β-cells by decreasing the expression of cleaved caspase-3, cleaved PARP and Bax, and increasing Bcl-2 by suppressing ER stress(Bip/XBP1/IRE1α/CHOP/Caspase-12) and autophagy(LC3/p62/Atg5) pathways.2/Atg5 pathways.展开更多
Proteins synthesized in the endoplasmic reticulum （ER） are properly folded with the assistance of ER chaperones. Accumulation of misfolded protein in the ER triggers an adaptive ER stress （ERS） response termed the...Proteins synthesized in the endoplasmic reticulum （ER） are properly folded with the assistance of ER chaperones. Accumulation of misfolded protein in the ER triggers an adaptive ER stress （ERS） response termed the unfolded protein response. Recent interest has focused on the possibility that the accumulation of misfolded proteins can also contribute to reproductive response, including preimplantation embryos, testicular germ cell, placenta, and unexplained intrauterine growth restriction （IUGR）. The major ERS pathway constituents are present at all stages of preimplantation development and that the activation of ERS pathways can be induced at the 8-cell, morula and blastocyst stage. This review mainly introduced the research progress of ERS induced apoptosis of reproductive cells, providing a new direction for the research of reproductive disease therapy.展开更多
基金supported by the China Mega-project for Infectious Disease [2018ZX10102001,2018ZX10711001,2018ZX10734401,and 2018ZX10734404]the SKLID Development Grant [2011SKLID104]
文摘Objective Autophagy is a highly conserved intracellular degradation pathway. Many picornaviruses induce autophagy to benefit viral replication, but an understanding of how autophagy occurs remains incomplete. In this study, we explored whether coxsackievirus B3(CVB3) infection induced autophagy through endoplasmic reticulum(ER) stress. Methods In CVB3-infected HeLa cells, the specific molecules of ER stress and autophagy were detected using Western blotting, reverse transcription polymerase chain reaction(RT-PCR), and confocal microscopy. Then PKR-like ER protein kinase(PERK) inhibitor, inositol-requiring protein-1(IRE1) inhibitor, or activating transcription factor-6(ATF6) inhibitor worked on CVB3-infected cells, their effect on autophagy was assessed by Western blotting for detecting microtubule-associated protein light chain 3(LC3). Results CVB3 infection induced ER stress, and ER stress sensors PERK/eIF2α, IRE1/XBP1, and ATF6 were activated. CVB3 infection increased the accumulation of green fluorescent protein(GFP)-LC3 punctuation and induced the conversion from LC3-Ⅰ to phosphatidylethanolamine-conjugated LC3-1(LC3-Ⅱ). CVB3 infection still decreased the expression of mammalian target of rapamycin(mTOR) and p-mTOR. Inhibition of PERK, IRE1, or ATF6 significantly decreased the ratio of LC3-Ⅱ to LC3-Ⅰ in CVB3-infected HeLa cells. Conclusion CVB3 infection induced autophagy through ER stress in HeL a cells, and PERK, IRE1, and ATF6 a pathways participated in the regulation of autophagy. Our data suggested that ER stress may inhibit mTOR signaling pathway to induce autophagy during CVB3 infection.
基金supported by the National Natural Science Foundation of China(81973350,China)supported by the National Natural Science Foundation of China(81872884 and 82173841,China)Beijing Natural Science Foundation(7222253,China)。
文摘The well-known insulin-like growth factor 1(IGF1)/IGF-1 receptor(IGF-1R)signaling pathway is overexpressed in many tumors,and is thus an attractive target for cancer treatment.However,results have often been disappointing due to crosstalk with other signals.Here,we report that IGF-1R signaling stimulates the growth of hepatocellular carcinoma(HCC)cells through the translocation of IGF-1R into the ER to enhance sarco-endoplasmic reticulum calcium ATPase 2(SERCA2)activity.In response to ligand binding,IGF-1Rβis translocated into the ER byβ-arrestin2(β-arr2).Mass spectrometry analysis identified SERCA2 as a target of ER IGF-1Rβ.SERCA2 activity is heavily dependent on the increase in ER IGF-1Rβlevels.ER IGF-1Rβphosphorylates SERCA2 on Tyr^(990)to enhance its activity.Mutation of SERCA2-Tyr^(990)disrupted the interaction of ER IGF-1Rβwith SERCA2,and therefore ER IGF-1Rβfailed to promote SERCA2 activity.The enhancement of SERCA2 activity triggered Ca_(ER)^(2+)perturbation,leading to an increase in autophagy.Thapsigargin blocked the interaction between SERCA2and ER IGF-1Rβand therefore SERCA2 activity,resulting in inhibition of HCC growth.In conclusion,the translocation of IGF-1R into the ER triggers Ca_(ER)^(2+)perturbation by enhancing SERCA2 activity through phosphorylating Tyr^(990)in HCC.
文摘Efficient functioning of the endoplasmic reticulum(ER) is very important for most cellular activities, such as protein folding and modification. The ER closely interacts with other organelles, including the Golgi body, endosome, membrane, and mitochondria, providing lipids and proteins for the repair of these organelles. ER stress can be induced by various abnormal materials in the cell. ER stress is a compensatory intracellular environment disorder that occurs during areaction. ER can sense the stress and respond to it through translational attenuation, upregulation of the genes for ER chaperones and related proteins, and degradation of unfolded proteins by a quality-control system, but excessive ER activation can cause cell death. The Pubmed and Web of Science databases were searched for full-text articles, and the terms "endoplasmic reticulum stress/unfolded protein response/gynecologic tumor cell apoptosis" were used as key words. Thirty-five studies of ER stress and unfolded protein response published from 2000 to 2016 were analyzed. Stress triggers apoptosis through a variety of signaling pathways. Increasing evidence has shown that the ER plays an important role in tumor cell diseases. The present review discusses the molecular mechanisms underlying unfolded protein response and its ability to promote survival and proliferation in gynecologic tumor cells.
基金This research is supported by funding from the National Natural Science Foundation of China(Grant No.81373025).
文摘Objective:To examine whether exposure of mouse neuronal cells to radiofrequency fields used in mobile communication devices can induce stress in endoplasmic reticulum(ER)and activate unfolded protein response(UPR).Methods:HT22 mouse hippocampus neuronal cells were exposed to continuous wave 900 MHz radiofrequency fields(RF)at 120μW/cm2 power intensity for 4 h/d for 5 consecutive days.The positive control cells were irradiated with 4 Gy of 60Coγ-rays at a dose rate of 0.5 Gy/min(GR).Twenty-four hours after the last exposure,cells were collected,and the expressions of sensor transmembrane proteins were detected using Western blot analysis.Results:The expression levels of Ire1,PERK,p-IRE1 and p-PERK,GRP78 and CHOP proteins were detected.There were no statistically significant differences in the expression levels of IRE1 and PERK proteins in control(CT),sham(SH)-,RF-and GR-exposed cells(P<0.05).The phosphorylated protein levels of p-IRE1 and p-PERK were significantly increased in cells exposed to RF and GR(P<0.05).The expression levels of GRP78 and CHOP were significantly increased in RF-and GR-exposed cells compared to CT and SH-exposed cells(P<0.05).Cells treated with 1μg/ml TM for 24 h showed significantly increased expression levels of GRP78 and CHOP proteins compared to controls(P<0.05).In the presence of 2 mmol/L PBA,TM-induced increased levels of GRP78 and CHOP proteins were reduced(P<0.05).Conclusions:The exposure of non-ionizing 900 MHz RF was able to cause stress in HT22 mouse neuronal cells and activated UPR in ER.Since UPR plays an important role in both cell survival(when UPR is mitigated)and apoptosis/death(under unresolvable stress conditions),further studies are required to determine the fate of the cells exposed to RF.
基金Supported by the National Natural Science Foundation of China(No.41676124)。
文摘Abstract The unfolded protein response(UPR)is an important protective and compensatory strategy used during endoplasmic reticulum stress caused by factors including glucose starvation,low pH,or heat shock.However,there is very little information on the possible role(s)of the UPR under adverse conditions experienced by marine invertebrates.We observed that rough endoplasmic reticulum(ER)was dramatically expanded and numerous autophagosomes were accumulated in the intestinal cells of sea cucumbers,Apostichopus japonicus,under heat stress(4 h at 25°C compared with 15°C controls).Moreover,heat stress led to sharp increases in the relative transcript and protein expression levels of two primary ER chaperones:the endoplasmic reticulum resident protein 29-like(ERP29)and protein disulfi de-isomerase A6-like(PDIA6).These results suggest a potential adaptive mechanism to deal with heat-induced stress in sea cucumber intestine.
文摘Objective： The aim of this study was to explore the mechanisms by which the flavonoid casticin enhances tumor necrosis factor-related apoptosis-inducing ligand （TRAIL）-induced apoptosis in colon cancer cells. Methods： Human colon cancer HT-29 cells were treated with TRAIL or casticin. Cytotoxicity was examined by MTT assay, and apoptosis determined by morphological observation and flow cytometric analysis. Death receptor 5 （DRS）, DR4, and endoplasmic reticulum （ER） stress response markers, including glucose regulating protein 78 （GRP78）, activating transcription factor 4 （ATF4） and CHOP （CCAAT/enhancer binding protein homologous protein）, were examined with western blot. Small interfering RNA （siRNA） transfection was employed to knock down CHOP. Results： HT-29 cells were resistance to TRAIL-induced apoptosis, but casticin, at subtoxic concentrations, potentiated HT-29 cells to TRAIL-induced apoptosis. Casticin up-regulated the expression of DR5 time-and dose-dependent manners, but had no effect on the expression of DR4. Also, casticin increased the levels of ER stress response markers （GRP78, ATF4 and CHOP） in a similar way to DR5. Knockdown of CHOP by specific siRNA, or salubrinal, an ER stress inhibitor, abolished the up-regulation of DR5 and enhancement of TRAIL-induced apoptosis by casticin. Conclusion： Casticin enhances TRAIL-induced apoptosis of colon cancer cells by ER stress-mediated up-regulation of DR5.
基金Special Fund for the Research Team of Ecological Restoration and Governance Innovation of the Jinsha River Dry and Hot Valley(035200179)2020 Doctoral Research Startup Fund of Panzhihua University(035200254)。
文摘Golgi apparatus,together with endoplasmic reticula,vacuoles and plasma membrane,constitutes the endoplasmic system of plant cells.It plays an important role in the secretion pathway of eukaryotic cells and is responsible for various intracellular events,such as protein classification,protein modification and glycosylation.At present,much less is known about plant Golgi proteins.The research on its function is still insufficient.In order to provide a comprehensive research background and research ideas for related researchers,this paper systematically and comprehensively evaluated the structure of plant endoplasmic system,the common endoplasmic reticulum-Golgi transport pathway in plant cells,various possible transport models between endoplasmic reticula and Golgi bodies,Golgi-associated specific proteins and functions,and Golgi biogenesis pathway.The latest research progress in this field was reviewed and analyzed in detail.This paper will provide an important reference for related researchers to carry out the research of plant Golgi.
基金This work was supported by USA National Institute of Diabetes and Digestive and Kidney Diseases(NIDDK)R01 DK093807.
文摘Endoplasmic reticulum(ER)stress occurs when ER homeostasis is perturbed with accumulation of unfolded/misfolded protein or calcium depletion.The unfolded protein response(UPR),comprising of inositol-requiring enzyme 1 a(IRE1 a),double-stranded RNA-dependent protein kinase(PKR)-like ER kinase(PERK)and activating transcription factor 6(ATF6)signaling pathways,is a protective cellular response activated by ER stress.However,UPR activation can also induce cell death upon persistent ER stress.The liver is susceptible to ER stress given its synthetic and other biological functions.Numerous studies from human liver samples and animal disease models have indicated a crucial role of ER stress and the UPR signaling pathways in the pathogenesis of liver diseases,including non-alcoholic fatty liver disease(NAFLD),alcoholic liver disease(ALD),alpha-1 antitrypsin(AAT)deficiency(AATD),cholestatic liver disease,drug-induced liver injury,ischemia/reperfusion(I/R)injury,viral hepatitis and hepatocel-lular carcinoma(HCC).Extensive investigations have demonstrated the potential underlying mechanisms of the induction of ER stress and the contribution of the UPR pathways during the development of the diseases.Moreover,ER stress and the UPR proteins and genes have become emerging therapeutic targets to treat liver diseases.
基金This work was supported by the Shanghai Shenkang Hospital Development Center’s Shenkang Promotion of Clin‑ical Skills and Clinical Innovation in Municipal Hospitals Three-Year Action Plan(No.2020‒2023)the Major Clinical Research Project(No.SHDC2020CR1048B)the Pilot Construction Project of High-Level Universities in Shanghai(No.DGF501017-06),China。
文摘Endoplasmic reticulum(ER)stress,as an emerging hallmark feature of cancer,has a considerable impact on cell proliferation,metastasis,invasion,and chemotherapy resistance.Ovarian cancer(OvCa)is one of the leading causes of cancer-related mortality across the world due to the late stage of disease at diagnosis.Studies have explored the influence of ER stress on OvCa in recent years,while the predictive role of ER stress-related genes in OvCa prognosis remains unexplored.Here,we enrolled 552 cases of ER stress-related genes involved in OvCa from The Cancer Genome Atlas(TCGA)and Gene Expression Omnibus(GEO)cohorts for the screening of prognosis-related genes.The least absolute shrinkage and selection operator(LASSO)regression was applied to establish an ER stress-related risk signature based on the TCGA cohort.A seven-gene signature revealed a favorable predictive efficacy for the TCGA,International Cancer Genome Consortium(ICGC),and another GEO cohort(P<0.001,P<0.001,and P=0.04,respectively).Moreover,functional annotation indicated that this signature was enriched in cellular response and senescence,cytokines interaction,as well as multiple immune-associated terms.The immune infiltration profiles further delineated an immunologic unresponsive status in the high-risk group.In conclusion,ER stress-related genes are vital factors predicting the prognosis of OvCa,and possess great application potential in the clinic.
基金This work was supported by grants from the National Natural Science Foundation of China(No.81360199)Science and Technology Department of Guizhou Province(Guizhou Specific Grant[2019]4008)+2 种基金Science and Technology Plan Project of Guizhou Province(Basic Science and Technology Cooperation[2020]1Z060)Science and Technology Fund Project of Guizhou Health and Health Commission(No.gzwjkj2019-1-039)Science and Technology Fund Project of Southwest Guizhou Autonomous Prefecture(2019-1-10).
文摘This study aimed to elucidate the molecular mechanisms by which berberine protects against cerebral ischemia/reperfusion(I/R)injury.The oxygen-glucose deprivation/reperfusion(OGD/R)PC12 model was established.Cell counting kit-8(CCK-8)was used to detect the toxicity of berberine and the viability of PC12 cells.Hoechst 33258 staining and flow cytometry were used to observe the nuclear morphology,and changes of apoptosis and reactive oxygen species(ROS),respectively.Western blotting and immunofluorescence assay were employed to detect autophagy-related proteins[microtubule-associated protein 1A/1B-light chain 3(LC3),P62/SQSTM-1,Beclin-1]and endoplasmic reticulum(ER)stress-related markers[glucose-regulated protein 78(GRP78),C/EBP homologous protein(CHOP),Bcl-2-associated X(Bax)and cleaved caspase-3].The GFP-RFP-LC3 adenovirus was used to assay the change of autophagic flux.Our results showed that berberine could increase the viability of PC12 cells,decrease the concentrations of ROS after OGD/R treatment,and suppress OGD/R-induced ER stress and autophagy.Moreover,the results revealed the involvement of the mammalian target of rapamycin(mTOR)pathway in the induction of autophagy,and berberine could activate the phosphorylation of mTOR and thus mitigate autophagy.In conclusion,our study suggested that berberine may protect against OGD/R-induced apoptosis by regulating ER stress and autophagy,and it holds promises in the treatment of cerebral I/R injury.
基金This work was supported by USA National Institutes of Health(NIH)grants AI125350,AI085087 and AI139234 to A.Siddiqui.
文摘Autophagy is a self-eating process,in which the damaged or excessed cell organelles and misfolded protein aggregates are removed from the cellular microenvironment.Autophagy is generally thought of as a pro-survival mechanism which is not only important for balancing energy supply at times of nutrient deprivation but also in the removal of various stress stimuli to ensure homeostasis.In addition to the target materials of“self”origin,autophagy can also eliminate intracellular pathogens and acts as a defense mechanism to curb infections.In addition,autophagy is linked to the host cell's innate immune response.However,viruses have evolved various strategies to manipulate and overtake host cell machinery to establish productive replication and maintain infectious process.In fact,replication of many viruses has been found to be autophagy-dependent and suppression of autophagy can potentially affect the viral replication.Thus,autophagy can either serve as an anti-viral defense mechanism or a pro-viral process that supports viral replication.Hepatitis B virus(HBV)and hepatitis C virus(HCV)are known to co-opt cellular autophagy process as a pro-viral tool.Both viruses also induce mitophagy,which contributes to the establishment of chronic hepatitis.This review focuses on the roles of autophagy and mitophagy in the chronic liver disease pathogenesis associated with HBV and HCV infections.
基金This workwas partially supported by the USA National Institutes of Health(NIH)grants:R01 AA020518,R01 DK102142,U01 AA024733 and P20GM103549&P30GM118247.
文摘The endoplasmic reticulum(ER)is an intracellular organelle consisting of a continuous network of membranes.In the liver,the ER is highly active in protein modification,lipid metabolism,and xenobiotic detoxification.Maintaining these complicated processes requires elaborate control of the ER lumen environment as well as the ER volume.Increasing evidence suggests that autophagy plays a critical role in regulating the homeostasis of hepatic ER contents and levels of cytochrome P450(CYP)enzymes via selective ER-phagy.This review will provide an overview of ER-phagy,summarizing the possible roles of recently identified ER-phagy receptor proteins in regulating the homeostasis of hepatic ER and CYP enzymes as well as outlining the various implications of ER-phagy in ER-related liver diseases.
基金Chinese Medicine Research Program of Hunan Province(No.201999)。
文摘Sangguayin preparation(SGY-P) is refined from the traditional Chinese medicinal compound Sangguayin, which"clears heat and promotes fluid" and "tonifies kidney and spleen" for "Xiaoke", commonly known as ‘Diabetes mellitus’ in clinics.Previous studies have shown that SGY-P could reduce insulin resistance and repair damaged pancreas in db/db mice, but the underlying mechanisms were unclear. Here, we investigated whether treatment with SGY-P could protect pancreatic β-cells from apoptosis and uncovered the underlying mechanisms. db/db mice were used to observe the hypoglycemic and islet protective effect in vivo. Apoptosis was induced in mouse insulinoma 6(MIN6) cells by palmitate, following which the cells were treated with SGY-P for elucidating the anti-apoptotic mechanism in vitro. Cell viability and nuclear morphology were detected by CCK-8 assay and Hoechst 33258 staining. The expression levels of apoptosis-, endoplasmic reticulum(ER) stress-, and autophagy-related proteins were measured by western blot. The results showed that SGY-P reduced fasting blood glucose, pancreatic pathological changes, and islet β-cell apoptosis in db/db mice. Palmitate-induced apoptosis in MIN6 cells was decreased by SGY-P treatment. Hence, SGY-P therapy exhibited a protective effect on pancreatic β-cells by decreasing the expression of cleaved caspase-3, cleaved PARP and Bax, and increasing Bcl-2 by suppressing ER stress(Bip/XBP1/IRE1α/CHOP/Caspase-12) and autophagy(LC3/p62/Atg5) pathways.2/Atg5 pathways.
文摘Proteins synthesized in the endoplasmic reticulum （ER） are properly folded with the assistance of ER chaperones. Accumulation of misfolded protein in the ER triggers an adaptive ER stress （ERS） response termed the unfolded protein response. Recent interest has focused on the possibility that the accumulation of misfolded proteins can also contribute to reproductive response, including preimplantation embryos, testicular germ cell, placenta, and unexplained intrauterine growth restriction （IUGR）. The major ERS pathway constituents are present at all stages of preimplantation development and that the activation of ERS pathways can be induced at the 8-cell, morula and blastocyst stage. This review mainly introduced the research progress of ERS induced apoptosis of reproductive cells, providing a new direction for the research of reproductive disease therapy.
