It has been shown that oncoprotein p28GANK, which is consistently overexpressed in human hepatocellular carcinoma （HCC）, plays a critical role in tumorigenesis of HCC. However, the underlying mechanism remains uncle...It has been shown that oncoprotein p28GANK, which is consistently overexpressed in human hepatocellular carcinoma （HCC）, plays a critical role in tumorigenesis of HCC. However, the underlying mechanism remains unclear. Here, we demonstrated that p28GANK inhibits apoptosis in HCC cells induced by the endoplasmic reticulum （ER） stress. During ER stress, p28GANK enhances the unfolded protein response, promotes ER recovery from translational repression, and thereby facilitates cell＇s ability to cope with the stress conditions. Furthermore, p28GANK upregulates glucose-regulated protein 78 （GRP78）, a key ER chaperone protein, which subsequently enhances the ER folding capacity and promotes recovery from ER stress. We also demonstrated that p28GANK increases p38 mitogen-activated protein kinase and Akt phosphorylation, and inhibits nuclear factor kappa B （NF-κB） activation under ER stress, which in turn contributes to GRP78 upregulation. Taken together, our results indicate that p28GANK inhibits ER stress-induced apoptosis in HCC cells, at least in part, by enhancing the adaptive response and GRP78 expression. We propose that p28GANK has potential implications for HCC progression under the ER stress conditions.展开更多
The incidence of obesity has dramatically increased in recent years.Consequently,obesity and associated disorders such as nonalcoholic fatty liver disease constitute a serious problem.Therefore,the contribution of adi...The incidence of obesity has dramatically increased in recent years.Consequently,obesity and associated disorders such as nonalcoholic fatty liver disease constitute a serious problem.Therefore,the contribution of adipose tissue to metabolic homeostasis has become a focus of interest.In this review,we discuss the latest discoveries that support the role of lipids in nonalcoholic fatty liver disease.We describe the common mechanisms(cJun aminoterminal kinases,endoplasmic reticulum stress,unfolded protein response,ceramide,lowgrade chronic inflammation)by which lipids and their derivatives impair insulin responsiveness and contribute to inflammatory liver and promote plaque instability in the arterial wall.Presenting the molecular mechanism of lipid activation of proinflammatory pathways,we attempt to find a link between nonalcoholic fatty liver disease,metabolic syndrome and cardiovascular diseases.Describing the common mechanisms by which lipid derivatives,through modulation of macrophage function,promote plaque instability in the arterial wall,impair insulin responsiveness and contribute to inflammatory liver and discussing the molecular mechanism of lipid activation of proinflammatory pathways,the key roles played by the proliferatoractivated receptor and liver X receptorα,nuclear receptorslipid sensors that link lipid metabolism and inflammation,should be emphasized.Further studies are warranted of antiinflammatory drugs such as aspirin,antiinterleukin6 receptors,immunemodulators(calcineurin inhibitors),substances enhancing the expression of heat shock proteins(which protect cells from endoplasmic reticulum stressinduced apoptosis),and anticJun aminoterminal kinases in welldesigned trials to try to minimize the high impact of these illnesses,and the different expressions of the diseases,on the whole population.展开更多
Background Endoplasmic reticulum （ER） stress-related apoptosis is involved in the pathophysiology of many cardiovascular diseases, and Panax quinquefolium saponin （PQS） is able to inhibit excessive ER stress-relat...Background Endoplasmic reticulum （ER） stress-related apoptosis is involved in the pathophysiology of many cardiovascular diseases, and Panax quinquefolium saponin （PQS） is able to inhibit excessive ER stress-related apoptosis of cardiomyocytes following hypoxia/reoxygenation and myocardial infarction. However, the pathway by which PQS inhibits the ER stress-related apoptosis is not well understood. To further investigate the protective effect of PQS against ER stress-related apoptosis, primary cultured eardiomyocytes were stimulated with thapsigargin （TG）, which is widely used to model cellular ER stress, and it could induce apoptotic cell death in sufficient concentration. Methods Primary cultured cardiomyocytes from neonatal rats were exposed to TG （1 μmol/L） treatment for 24 h, following PQS pre-treatment （160 μg/mL） for 24 h or pre-treatment with small interfering RNA directed against protein kinase-like endoplasmic reticulum kinase （Si-PERK） for 6 h. The viability and apoptosis rate of cardiomyocytes were detected by cell counting kit-8 and flow cytometry respectively. ER stress-related protein expression, such as glucose-regulated protein 78 （GRP78）, calreticulin, PERK, eukaryotic translation initiation factor 2α （elF2c0, activating transcription factor 4 （ATF4）, and C/EBP homologous protein （CHOP） were assayed by western blotting. Results Both PQS pre-treatment and PERK knockdown remarkably inhibited the cardiomyocyte apoptosis induced by TG, increased cell viability, decreased phosphorylation of both PERK and eIF2α, and decreased protein levels of both ATF4 and CHOP. There was no statistically significant difference between PQS pre-treatment and PERK knockdown in the cardioprotective effect. Conclusions Our data indicate that the PERK-eIF2α-ATF4-CHOP pathway of ER stress is involved in the apoptosis induced by TG, and PQS might prevent TG-induced cardiomyocyte apoptosis through a mechanism involving the suppression of this pathway. These findings provide novel data regarding the molecular mechanisms by which PQS inhibits cardiomyocyte apoptosis.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
Huanglian Jiedu Decoction(HLJDD)is a quintessential prescription renowned for its heat-clearing and detoxifying properties.It is primarily prescribed to counteract the syndrome characterized by the excessive heat of t...Huanglian Jiedu Decoction(HLJDD)is a quintessential prescription renowned for its heat-clearing and detoxifying properties.It is primarily prescribed to counteract the syndrome characterized by the excessive heat of the Sanjiao fire.Notably,the hyperactivity of liver fire is frequently linked with hypertension,where wind fire and wind toxicity emerge as pivotal pathogenic factors.This study aimed to investigate the impact of HLJDD on the endoplasmic reticulum in spontaneously hypertensive rats(SHR),further delving into the interplay between endoplasmic reticulum stress(ERS)and myocardial remodeling and damage.Fifty SHR rats were stratified randomly into five cohorts:model,low-dose HLJDD,medium-dose HLJDD,high-dose HLJDD,and captopril groups.For comparison,a set of Wistar-Kyoto(WKY)rats served as the baseline control group,with each group comprising 10 rats.While the model and control groups received equivalent volumes of normal saline via gavage,the other groups were administered the respective drug dosages through the same route daily for a span of 6 weeks.Upon the experiment’s conclusion,metrics such as the heart mass index(HWI)and left ventricular mass index(LVWI)were assessed.Cardiac tissue anomalies were identified using H&E staining,while ERS-related protein and mRNA expression levels were ascertained via Western blotting analysis and qPCR.Moreover,TUNEL staining was employed to detect cardiomyocyte apoptosis.The findings indicated that increasing HLJDD concentrations corresponded with escalated HWI and LVWI in rat hearts(P<0.05).There was a marked enhancement in myocardial structural integrity,accompanied by a notable reduction in collagen fibers.The mRNA and protein expressions of myocardial inositol-dependent enzyme 1α(IRE1α),X-box binding protein 1(XBP1),glycoregulatory protein 78(GRP78),and CCAAT enhancer binding protein homologous protein(CHOP)in the medium and high-dose groups saw significant declines(P<0.05).These effects mirrored those observed in the captopril group.The study underscored HLJDD’s efficacy in mitigating myocardial tissue damage in SHR.This therapeutic effect was potentially attributed to the downregulation of IRE1α,XBP1,GRP78,and CHOP,curbing excessive ERS,diminishing cardiomyocyte apoptosis,and thereby conferring cardioprotection.展开更多
The response to endoplasmic reticulum(ER)stress has been noted in both human depression cases and depression models in rodents.Wuling powder,derived from the mycelium of the esteemed fungus Xylaria Nigripes(Kl.)Sacc,h...The response to endoplasmic reticulum(ER)stress has been noted in both human depression cases and depression models in rodents.Wuling powder,derived from the mycelium of the esteemed fungus Xylaria Nigripes(Kl.)Sacc,has demonstrated efficacy in alleviating depressive symptoms.The purpose of this research was to explore the antidepressant properties of Wuling powder and its basic molecular effects,particularly regarding alterations in ER stress.A model of social defeat stress was created by introducing a mouse to the cage of an unfamiliar,hostile mouse for intervals of 5–10 min daily over a span of 10 d.Subsequently,the mice received oral doses of Wuling powder for 2 weeks.The social approach-avoidance assay was employed to evaluate signs of depression-like behaviors.Moreover,protein and gene expressions linked to ER stress triggered by social defeat were analyzed through Western blotting analysis and quantitative real-time PCR.The behavioral tests indicated that Wuling powder ameliorated behaviors associated with depression due to social defeat stress.Treatment with Wuling powder markedly reduced the increased levels of the 78-k Da glucose-regulated protein and protein disulfide isomerase caused by social defeat stress.It also diminished the expression of inositol-requiring enzyme 1α(IRE1α)and spliced X box-binding protein-1(s XBP1)at the protein and m RNA levels.Furthermore,Wuling treatment notably decreased the levels of phosphorylated eukaryotic initiation factor 2 alpha kinase(P-e IF2α),activating transcription factor 4(ATF4)and C/EBP homologous protein(CHOP),simultaneously enhancing the ratio of B-cell lymphoma 2(Bcl-2)to Bcl-2-associated X protein(Bax).These results suggested that Wuling powder could alleviate ER stress and inhibit cell apoptosis in the hippocampus by inhibiting protein translation and synthesis,thereby attenuating depressive-like behavior.展开更多
The mechanisms of brain ischemic insult include glutamate excitoxicity, calcium toxicity, free radicals, nitric oxide, inflammatory reactions, as well as dysfunctions of endoplasmic reticulum and mitochondrion. These ...The mechanisms of brain ischemic insult include glutamate excitoxicity, calcium toxicity, free radicals, nitric oxide, inflammatory reactions, as well as dysfunctions of endoplasmic reticulum and mitochondrion. These injury cascades are interconnected in complex ways, thus it is hard to compare their pathogenic importances in ischemia models. And the research in cellular and molecular pathways has spurred the studies in potential neuroprotections mainly in pharmacological fields, such as anti-excitotoxic treatment, calcium-channel antagonism, approaches for inhibition of oxidation, inflammation and apoptosis, etc. Besides, other protective interventions including thrombolysis, arteriogenesis, regeneration therapy, and ischemia preconditioning or postconditioning, are also under investigations. Despite the present difficulties, we are quite optimistic towards future clinical applications of neuroprotective agents, by optimizing experimental approaches and clinical trials.展开更多
Within the cell, several mechanisms exist to maintain homeostasis of the endoplasmic reticulum （ER）. One of the primary mechanisms is the unfolded protein response （UPR）. In this review, we primarily focus on the ...Within the cell, several mechanisms exist to maintain homeostasis of the endoplasmic reticulum （ER）. One of the primary mechanisms is the unfolded protein response （UPR）. In this review, we primarily focus on the latest signal webs and regulation mechanisms of the UPR. The relationships among ER stress, apoptosis, and cancer are also discussed. Under the normal state, binding immunoglobulin protein （BiP） interacts with the three sensors （protein kinase RNA-like ER kinase （PERK）, activating transcription factor 6 （ATF6）, and inositol-requiring enzyme la （IREla）） Under ER stress, misfolded proteins interact with BiP, resulting in the release of BiP from the sensors. Subsequently, the three sensors dimerize and autophosphorylate to promote the signal cascades of ER stress. ER stress includes a series of positive and negative feedback signals, such as those regulating the stabilization of the sensors/BiP complex, activating and inactivating the sensors by autophosphorylation and dephosphorylation, activating specific transcription factors to enable selective transcription, and augmenting the ability to refold and export. Apart from the three basic pathways, vascular endothelial growth factor （VEGF）-VEGF receptor （VEGFR）-phospholipase C-~ （PLCy）-mammalian target of rapamycin complex 1 （mTORC1） pathway, induced only in solid tumors, can also activate ATF6 and PERK signal cascades, and IREla also can be activated by activated RAC-alpha serine/threonine-protein kinase （AKT）. A moderate UPR functions as a pro-survival signal to return the cell to its state of homeostasis. However, persistent ER stress will induce cells to undergo apoptosis in response to increasing reactive oxygen species （ROS）, Ca2＋ in the cytoplasmic matrix, and other apoptosis signal cascades, such as c-Jun N-terminal kinase （JNK）, signal transducer and activator of transcription 3 （STAT3）, and P38, when cellular damage exceeds the capacity of this adaptive response.展开更多
Since the discovery of leptin as an adipokine in 1994, much progress has been made in the research about leptin. Circulating leptin binds to leptin receptor, activates STAT3-dependent and STAT3-independent signaling p...Since the discovery of leptin as an adipokine in 1994, much progress has been made in the research about leptin. Circulating leptin binds to leptin receptor, activates STAT3-dependent and STAT3-independent signaling pathways, and plays an effective role in energy home- ostasis, neuroendocrine function and metabolism mainly through acting on the central nervous system, especially the hypothalamus. Leptin resistance is considered as a key risk factor for obesity. Various mechanisms have been formu- lated in order to explain leptin resistance, including impairment in leptin transport, attenuation in leptin sig- naling, ER stress, inflammation and deficiency in autop- hagy. Here, we review our current knowledge about leptin action, leptin signaling and leptin resistance, hoping to provide new ideas for the battle against obesity.展开更多
Salusins are regulatory peptides that affect cardiovascular function. We previously reported that salusin-a and -β protected cultured cardiomyocytes from serum deprivation-induced cell death through upregulating gluc...Salusins are regulatory peptides that affect cardiovascular function. We previously reported that salusin-a and -β protected cultured cardiomyocytes from serum deprivation-induced cell death through upregulating glucose-regulated protein 78 （GRP78）, an endoplasmic reticulum （ER） resident protein whose overexpression acts as a marker and suppressor of ER stress. The present study examined whether salusin-α and -β inhibit ER stress in ischemic myocardium. In a rat model of myocardial infarction created by ligating the left anterior descending coronary artery （LAD）, salusin-α or -β was intravenously injected at 5 or 15 nmol kg-1 15 min prior to 2 h of LAD occlusion. The high dose of salusin-α and -β3 significantly improved heart function and hemodynamics in LAD-occluded rats, but had no effects in sham-operated rats. The arrhythmias caused by LAD oc- clusion were markedly attenuated by salusin-α and -β. The apoptotic rate in ischemic myocardium was reduced from 31.5%±3.7% to 19.8%±2.2% and 12.3%±2.2%, and the infarct size was reduced from 53.4%±4.0% of the risk area to 26.5%±9.7% and 23.7%±8.9% by 15 nmol kg-1 salusin-α and -β, respectively. Furthermore, salusin-α and -β prevented the ac- tivation of GRP78 and ER stress-specific apoptotic effectors caspase-12 and CHOP （C/EBP homologous protein）, and attenu- ated the reduction of an ER stress-associated antiapoptotic protein Bcl-2 in ischemic cardiac tissue. The salusins also inhibited the ER stress induced by tunicamycin in cultured rat H9c2 cardiomyocytes. These results indicate that salusins protect myo- cardium against ischemic injury by inhibiting ER stress and ER stress-associated apoptosis.展开更多
MicroRNAs, a class of small noncoding RNAs, play key roles in diverse biological and pathological processes. ER stress, resulting from the accumulation of unfolded or misfolded proteins in the ER lumen, is triggered b...MicroRNAs, a class of small noncoding RNAs, play key roles in diverse biological and pathological processes. ER stress, resulting from the accumulation of unfolded or misfolded proteins in the ER lumen, is triggered by various physiological events and pathological insults. Here, using RNA deep sequencing analysis, we found that the expression of some microRNAs was altered in HeLa and HEK293 cells under ER stress. Protein and RNA levels of DGCR8, Drosha, Exportin-5, Dicer, and Ago2 showed no significant alteration in ER-stressed cells, which suggested that the change in microRNA expression might not be caused by the microRNA biogenesis pathway but by other, unknown factors. Real-time PCR assays confirmed that hsa-miR-423-5p was up-regulated, whereas hsa-miR-221-3p and hsa-miR-452-5p were down-regulated, in both HeLa and HEK293 cells under ER stress. Luciferase activity and Western blot assays verified that CDKN1A was a direct target of hsa-miR-423-5p and that CDKN1B was a direct target of hsa-miR-221-3p and hsamiR-452-5p. We speculated that by regulating their targets, microRNAs might function cooperatively as regulators in the adaptive response to ER stress.展开更多
The present study was designed to analyze the metabolites of all-trans-retinal(atRal) and compare the cytotoxicity of atRal versus its derivative all-trans-retinoic acid(atRA) in human retinal pigment epithelial(RPE) ...The present study was designed to analyze the metabolites of all-trans-retinal(atRal) and compare the cytotoxicity of atRal versus its derivative all-trans-retinoic acid(atRA) in human retinal pigment epithelial(RPE) cells. We confirmed that atRA was produced in normal pig neural retina and RPE. The amount of all-trans-retinol(atROL) converted from atRal was about 2.7 times that of atRal-derived atRA after incubating RPE cells with 10 μmol/L atRal for 24 h, whereas atRA in medium supernatant is more plentiful(91 vs. 29 pmol/mL), suggesting that atRA conversion ? facilitates elimination of excess atRal in the retina. Moreover, we found that mRNA expression of retinoic acid-specific hydroxylase CYP26 b1 was dose-dependently up-regulated by atRal exposure in RPE cells, indicating that atRA inactivation may be also initiated in atRal-accumulated RPE cells. Our data show that atRA-caused viability inhibition was evidently reduced compared with the equal concentration of its precursor atRal. Excess accumulation of atRal provoked intracellular reactive oxygen species(ROS) overproduction, heme oxygenase-1(HO-1) expression, and increased cleaved poly(ADP-ribose) polymerase 1(PARP1) expression in RPE cells. In contrast, comparable dosage of atRA-induced oxidative stress was much weaker, and it could not activate apoptosis in RPE cells. These results suggest that atRA generation is an antidotal metabolism pathway for atRal in the retina. Moreover, we found that in the eyes of ABCA4-/-RDH8-/-mice, a mouse model with atRal accumulation in the retina, the atRA content was almost the same as that in the wild type. It is possible that atRal accumulation simultaneously and equally promotes atRA synthesis and clearance in eyes of ABCA4-/-RDH8-/-mice, thus inhibiting the further increase of atRA in the retina. Our present study provides further insights into atRal clearance in the retina.展开更多
文摘It has been shown that oncoprotein p28GANK, which is consistently overexpressed in human hepatocellular carcinoma （HCC）, plays a critical role in tumorigenesis of HCC. However, the underlying mechanism remains unclear. Here, we demonstrated that p28GANK inhibits apoptosis in HCC cells induced by the endoplasmic reticulum （ER） stress. During ER stress, p28GANK enhances the unfolded protein response, promotes ER recovery from translational repression, and thereby facilitates cell＇s ability to cope with the stress conditions. Furthermore, p28GANK upregulates glucose-regulated protein 78 （GRP78）, a key ER chaperone protein, which subsequently enhances the ER folding capacity and promotes recovery from ER stress. We also demonstrated that p28GANK increases p38 mitogen-activated protein kinase and Akt phosphorylation, and inhibits nuclear factor kappa B （NF-κB） activation under ER stress, which in turn contributes to GRP78 upregulation. Taken together, our results indicate that p28GANK inhibits ER stress-induced apoptosis in HCC cells, at least in part, by enhancing the adaptive response and GRP78 expression. We propose that p28GANK has potential implications for HCC progression under the ER stress conditions.
文摘The incidence of obesity has dramatically increased in recent years.Consequently,obesity and associated disorders such as nonalcoholic fatty liver disease constitute a serious problem.Therefore,the contribution of adipose tissue to metabolic homeostasis has become a focus of interest.In this review,we discuss the latest discoveries that support the role of lipids in nonalcoholic fatty liver disease.We describe the common mechanisms(cJun aminoterminal kinases,endoplasmic reticulum stress,unfolded protein response,ceramide,lowgrade chronic inflammation)by which lipids and their derivatives impair insulin responsiveness and contribute to inflammatory liver and promote plaque instability in the arterial wall.Presenting the molecular mechanism of lipid activation of proinflammatory pathways,we attempt to find a link between nonalcoholic fatty liver disease,metabolic syndrome and cardiovascular diseases.Describing the common mechanisms by which lipid derivatives,through modulation of macrophage function,promote plaque instability in the arterial wall,impair insulin responsiveness and contribute to inflammatory liver and discussing the molecular mechanism of lipid activation of proinflammatory pathways,the key roles played by the proliferatoractivated receptor and liver X receptorα,nuclear receptorslipid sensors that link lipid metabolism and inflammation,should be emphasized.Further studies are warranted of antiinflammatory drugs such as aspirin,antiinterleukin6 receptors,immunemodulators(calcineurin inhibitors),substances enhancing the expression of heat shock proteins(which protect cells from endoplasmic reticulum stressinduced apoptosis),and anticJun aminoterminal kinases in welldesigned trials to try to minimize the high impact of these illnesses,and the different expressions of the diseases,on the whole population.
基金Acknowledgements This work was supported by International Science and Technology Cooperation Project （2010DFA31690）, National Natural Science Foundation of China （81030063 and 81170140） and China Postdoctoral Science Foundation （2014M562608）. The authors declare no conflict of interests regarding the publication of this paper.
文摘Background Endoplasmic reticulum （ER） stress-related apoptosis is involved in the pathophysiology of many cardiovascular diseases, and Panax quinquefolium saponin （PQS） is able to inhibit excessive ER stress-related apoptosis of cardiomyocytes following hypoxia/reoxygenation and myocardial infarction. However, the pathway by which PQS inhibits the ER stress-related apoptosis is not well understood. To further investigate the protective effect of PQS against ER stress-related apoptosis, primary cultured eardiomyocytes were stimulated with thapsigargin （TG）, which is widely used to model cellular ER stress, and it could induce apoptotic cell death in sufficient concentration. Methods Primary cultured cardiomyocytes from neonatal rats were exposed to TG （1 μmol/L） treatment for 24 h, following PQS pre-treatment （160 μg/mL） for 24 h or pre-treatment with small interfering RNA directed against protein kinase-like endoplasmic reticulum kinase （Si-PERK） for 6 h. The viability and apoptosis rate of cardiomyocytes were detected by cell counting kit-8 and flow cytometry respectively. ER stress-related protein expression, such as glucose-regulated protein 78 （GRP78）, calreticulin, PERK, eukaryotic translation initiation factor 2α （elF2c0, activating transcription factor 4 （ATF4）, and C/EBP homologous protein （CHOP） were assayed by western blotting. Results Both PQS pre-treatment and PERK knockdown remarkably inhibited the cardiomyocyte apoptosis induced by TG, increased cell viability, decreased phosphorylation of both PERK and eIF2α, and decreased protein levels of both ATF4 and CHOP. There was no statistically significant difference between PQS pre-treatment and PERK knockdown in the cardioprotective effect. Conclusions Our data indicate that the PERK-eIF2α-ATF4-CHOP pathway of ER stress is involved in the apoptosis induced by TG, and PQS might prevent TG-induced cardiomyocyte apoptosis through a mechanism involving the suppression of this pathway. These findings provide novel data regarding the molecular mechanisms by which PQS inhibits cardiomyocyte apoptosis.
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The National Natural Science Foundation of China(Grant No.81860831)the Shandong Provincial Key Project of Traditional Chinese Medicine Science and Technology(Grant Nos.M-2023170,M-2022233).
文摘Huanglian Jiedu Decoction(HLJDD)is a quintessential prescription renowned for its heat-clearing and detoxifying properties.It is primarily prescribed to counteract the syndrome characterized by the excessive heat of the Sanjiao fire.Notably,the hyperactivity of liver fire is frequently linked with hypertension,where wind fire and wind toxicity emerge as pivotal pathogenic factors.This study aimed to investigate the impact of HLJDD on the endoplasmic reticulum in spontaneously hypertensive rats(SHR),further delving into the interplay between endoplasmic reticulum stress(ERS)and myocardial remodeling and damage.Fifty SHR rats were stratified randomly into five cohorts:model,low-dose HLJDD,medium-dose HLJDD,high-dose HLJDD,and captopril groups.For comparison,a set of Wistar-Kyoto(WKY)rats served as the baseline control group,with each group comprising 10 rats.While the model and control groups received equivalent volumes of normal saline via gavage,the other groups were administered the respective drug dosages through the same route daily for a span of 6 weeks.Upon the experiment’s conclusion,metrics such as the heart mass index(HWI)and left ventricular mass index(LVWI)were assessed.Cardiac tissue anomalies were identified using H&E staining,while ERS-related protein and mRNA expression levels were ascertained via Western blotting analysis and qPCR.Moreover,TUNEL staining was employed to detect cardiomyocyte apoptosis.The findings indicated that increasing HLJDD concentrations corresponded with escalated HWI and LVWI in rat hearts(P<0.05).There was a marked enhancement in myocardial structural integrity,accompanied by a notable reduction in collagen fibers.The mRNA and protein expressions of myocardial inositol-dependent enzyme 1α(IRE1α),X-box binding protein 1(XBP1),glycoregulatory protein 78(GRP78),and CCAAT enhancer binding protein homologous protein(CHOP)in the medium and high-dose groups saw significant declines(P<0.05).These effects mirrored those observed in the captopril group.The study underscored HLJDD’s efficacy in mitigating myocardial tissue damage in SHR.This therapeutic effect was potentially attributed to the downregulation of IRE1α,XBP1,GRP78,and CHOP,curbing excessive ERS,diminishing cardiomyocyte apoptosis,and thereby conferring cardioprotection.
基金National Natural Science Foundation of China(Grant No.81100801 and 81050025)the foundation of Zhejiang Jolly Pharmaceutical Co.,Ltd.
文摘The response to endoplasmic reticulum(ER)stress has been noted in both human depression cases and depression models in rodents.Wuling powder,derived from the mycelium of the esteemed fungus Xylaria Nigripes(Kl.)Sacc,has demonstrated efficacy in alleviating depressive symptoms.The purpose of this research was to explore the antidepressant properties of Wuling powder and its basic molecular effects,particularly regarding alterations in ER stress.A model of social defeat stress was created by introducing a mouse to the cage of an unfamiliar,hostile mouse for intervals of 5–10 min daily over a span of 10 d.Subsequently,the mice received oral doses of Wuling powder for 2 weeks.The social approach-avoidance assay was employed to evaluate signs of depression-like behaviors.Moreover,protein and gene expressions linked to ER stress triggered by social defeat were analyzed through Western blotting analysis and quantitative real-time PCR.The behavioral tests indicated that Wuling powder ameliorated behaviors associated with depression due to social defeat stress.Treatment with Wuling powder markedly reduced the increased levels of the 78-k Da glucose-regulated protein and protein disulfide isomerase caused by social defeat stress.It also diminished the expression of inositol-requiring enzyme 1α(IRE1α)and spliced X box-binding protein-1(s XBP1)at the protein and m RNA levels.Furthermore,Wuling treatment notably decreased the levels of phosphorylated eukaryotic initiation factor 2 alpha kinase(P-e IF2α),activating transcription factor 4(ATF4)and C/EBP homologous protein(CHOP),simultaneously enhancing the ratio of B-cell lymphoma 2(Bcl-2)to Bcl-2-associated X protein(Bax).These results suggested that Wuling powder could alleviate ER stress and inhibit cell apoptosis in the hippocampus by inhibiting protein translation and synthesis,thereby attenuating depressive-like behavior.
基金supported by 211 Project Special Fund for Key Laboratory of Neuroimmunology,Science and Technology Projects for Returned Overseas Chinese Scholars of Heilongjiang Province (LC06C26)China Postdoctoral Science Foundation (No.20060390236)
文摘The mechanisms of brain ischemic insult include glutamate excitoxicity, calcium toxicity, free radicals, nitric oxide, inflammatory reactions, as well as dysfunctions of endoplasmic reticulum and mitochondrion. These injury cascades are interconnected in complex ways, thus it is hard to compare their pathogenic importances in ischemia models. And the research in cellular and molecular pathways has spurred the studies in potential neuroprotections mainly in pharmacological fields, such as anti-excitotoxic treatment, calcium-channel antagonism, approaches for inhibition of oxidation, inflammation and apoptosis, etc. Besides, other protective interventions including thrombolysis, arteriogenesis, regeneration therapy, and ischemia preconditioning or postconditioning, are also under investigations. Despite the present difficulties, we are quite optimistic towards future clinical applications of neuroprotective agents, by optimizing experimental approaches and clinical trials.
基金Project supported by the National Basic Research Program(973)of China(No.2012CB518900)the National Natural Science Foundation of China(Nos.31160240 and 31260621)+2 种基金the National Major Scientific and Technological Special Project during the Twelfth Five-year Plan Period of China(No.2012ZX10002006)the Hangzhou Normal University Supporting Project(No.PE13002004042)the Natural Science Foundation of Jiangxi Province(No.20114BAB204016),China
文摘Within the cell, several mechanisms exist to maintain homeostasis of the endoplasmic reticulum （ER）. One of the primary mechanisms is the unfolded protein response （UPR）. In this review, we primarily focus on the latest signal webs and regulation mechanisms of the UPR. The relationships among ER stress, apoptosis, and cancer are also discussed. Under the normal state, binding immunoglobulin protein （BiP） interacts with the three sensors （protein kinase RNA-like ER kinase （PERK）, activating transcription factor 6 （ATF6）, and inositol-requiring enzyme la （IREla）） Under ER stress, misfolded proteins interact with BiP, resulting in the release of BiP from the sensors. Subsequently, the three sensors dimerize and autophosphorylate to promote the signal cascades of ER stress. ER stress includes a series of positive and negative feedback signals, such as those regulating the stabilization of the sensors/BiP complex, activating and inactivating the sensors by autophosphorylation and dephosphorylation, activating specific transcription factors to enable selective transcription, and augmenting the ability to refold and export. Apart from the three basic pathways, vascular endothelial growth factor （VEGF）-VEGF receptor （VEGFR）-phospholipase C-~ （PLCy）-mammalian target of rapamycin complex 1 （mTORC1） pathway, induced only in solid tumors, can also activate ATF6 and PERK signal cascades, and IREla also can be activated by activated RAC-alpha serine/threonine-protein kinase （AKT）. A moderate UPR functions as a pro-survival signal to return the cell to its state of homeostasis. However, persistent ER stress will induce cells to undergo apoptosis in response to increasing reactive oxygen species （ROS）, Ca2＋ in the cytoplasmic matrix, and other apoptosis signal cascades, such as c-Jun N-terminal kinase （JNK）, signal transducer and activator of transcription 3 （STAT3）, and P38, when cellular damage exceeds the capacity of this adaptive response.
基金Acknowledgments This work was supported by the National Basic Research Program of China （2013CB530601, 2011CB910201）, the National Natural Science Foundation of China （31571401, 81270954, 31030048, 81390350）, the Shanghai Rising Star Program （13QH1400800）. The Department of Biochemistry and Molecular Biology at Fudan University Shanghai Medical College is supported by the Shanghai Leading Academic Discipline Projects B 110 and by ＂985＂ Project 985III-YFX0302.
文摘Since the discovery of leptin as an adipokine in 1994, much progress has been made in the research about leptin. Circulating leptin binds to leptin receptor, activates STAT3-dependent and STAT3-independent signaling pathways, and plays an effective role in energy home- ostasis, neuroendocrine function and metabolism mainly through acting on the central nervous system, especially the hypothalamus. Leptin resistance is considered as a key risk factor for obesity. Various mechanisms have been formu- lated in order to explain leptin resistance, including impairment in leptin transport, attenuation in leptin sig- naling, ER stress, inflammation and deficiency in autop- hagy. Here, we review our current knowledge about leptin action, leptin signaling and leptin resistance, hoping to provide new ideas for the battle against obesity.
基金supported by the National Basic Research Program of China (Grant Nos. 2006CB503807 and 2009CB521902)the National Natural Science Foundation of China (Grant Nos. 30600763, 30870906, and 31071023)+2 种基金the Pujiang Project of Shanghai, China (Grant No.08PJ14001)the Project Sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, Ministry of Education of China (Grant No. [2008]891)the Fund for Outstanding Young Teachers in Higher Education Institutions of Shanghai, China (Grant No.[2009]63)
文摘Salusins are regulatory peptides that affect cardiovascular function. We previously reported that salusin-a and -β protected cultured cardiomyocytes from serum deprivation-induced cell death through upregulating glucose-regulated protein 78 （GRP78）, an endoplasmic reticulum （ER） resident protein whose overexpression acts as a marker and suppressor of ER stress. The present study examined whether salusin-α and -β inhibit ER stress in ischemic myocardium. In a rat model of myocardial infarction created by ligating the left anterior descending coronary artery （LAD）, salusin-α or -β was intravenously injected at 5 or 15 nmol kg-1 15 min prior to 2 h of LAD occlusion. The high dose of salusin-α and -β3 significantly improved heart function and hemodynamics in LAD-occluded rats, but had no effects in sham-operated rats. The arrhythmias caused by LAD oc- clusion were markedly attenuated by salusin-α and -β. The apoptotic rate in ischemic myocardium was reduced from 31.5%±3.7% to 19.8%±2.2% and 12.3%±2.2%, and the infarct size was reduced from 53.4%±4.0% of the risk area to 26.5%±9.7% and 23.7%±8.9% by 15 nmol kg-1 salusin-α and -β, respectively. Furthermore, salusin-α and -β prevented the ac- tivation of GRP78 and ER stress-specific apoptotic effectors caspase-12 and CHOP （C/EBP homologous protein）, and attenu- ated the reduction of an ER stress-associated antiapoptotic protein Bcl-2 in ischemic cardiac tissue. The salusins also inhibited the ER stress induced by tunicamycin in cultured rat H9c2 cardiomyocytes. These results indicate that salusins protect myo- cardium against ischemic injury by inhibiting ER stress and ER stress-associated apoptosis.
基金supported by the National Basic Research Program of China (2011CBA01103)the National Natural Science Foundation of China (81372215, 31301069, 81171074, and 91232702)+2 种基金the Science Foundation of the Chinese Academy of Sciences (KJZD-EW-L01-2)Anhui Provincial Natural Science Foundation (1408085MC42)the Fundamental Research Funds for the Central Universities (WK2070000034)
文摘MicroRNAs, a class of small noncoding RNAs, play key roles in diverse biological and pathological processes. ER stress, resulting from the accumulation of unfolded or misfolded proteins in the ER lumen, is triggered by various physiological events and pathological insults. Here, using RNA deep sequencing analysis, we found that the expression of some microRNAs was altered in HeLa and HEK293 cells under ER stress. Protein and RNA levels of DGCR8, Drosha, Exportin-5, Dicer, and Ago2 showed no significant alteration in ER-stressed cells, which suggested that the change in microRNA expression might not be caused by the microRNA biogenesis pathway but by other, unknown factors. Real-time PCR assays confirmed that hsa-miR-423-5p was up-regulated, whereas hsa-miR-221-3p and hsa-miR-452-5p were down-regulated, in both HeLa and HEK293 cells under ER stress. Luciferase activity and Western blot assays verified that CDKN1A was a direct target of hsa-miR-423-5p and that CDKN1B was a direct target of hsa-miR-221-3p and hsamiR-452-5p. We speculated that by regulating their targets, microRNAs might function cooperatively as regulators in the adaptive response to ER stress.
基金Project supported by the Zhejiang Provincial Natural Science Foundation of China(No.LQ17H120001)the Medical Science and Technology Program of Zhejiang Province(Nos.2016KYA195 and 2017KY714)+1 种基金the National Natural Science Foundation of China(No.81801424)the 211 Talents Training Program of Taizhou,China
文摘The present study was designed to analyze the metabolites of all-trans-retinal(atRal) and compare the cytotoxicity of atRal versus its derivative all-trans-retinoic acid(atRA) in human retinal pigment epithelial(RPE) cells. We confirmed that atRA was produced in normal pig neural retina and RPE. The amount of all-trans-retinol(atROL) converted from atRal was about 2.7 times that of atRal-derived atRA after incubating RPE cells with 10 μmol/L atRal for 24 h, whereas atRA in medium supernatant is more plentiful(91 vs. 29 pmol/mL), suggesting that atRA conversion ? facilitates elimination of excess atRal in the retina. Moreover, we found that mRNA expression of retinoic acid-specific hydroxylase CYP26 b1 was dose-dependently up-regulated by atRal exposure in RPE cells, indicating that atRA inactivation may be also initiated in atRal-accumulated RPE cells. Our data show that atRA-caused viability inhibition was evidently reduced compared with the equal concentration of its precursor atRal. Excess accumulation of atRal provoked intracellular reactive oxygen species(ROS) overproduction, heme oxygenase-1(HO-1) expression, and increased cleaved poly(ADP-ribose) polymerase 1(PARP1) expression in RPE cells. In contrast, comparable dosage of atRA-induced oxidative stress was much weaker, and it could not activate apoptosis in RPE cells. These results suggest that atRA generation is an antidotal metabolism pathway for atRal in the retina. Moreover, we found that in the eyes of ABCA4-/-RDH8-/-mice, a mouse model with atRal accumulation in the retina, the atRA content was almost the same as that in the wild type. It is possible that atRal accumulation simultaneously and equally promotes atRA synthesis and clearance in eyes of ABCA4-/-RDH8-/-mice, thus inhibiting the further increase of atRA in the retina. Our present study provides further insights into atRal clearance in the retina.
