In this study,endoplasmic reticulum(ER)stress inducer tunicamycin(TM)and inhibitor 4-phenylbutyric acid(4-PBA)were used to treat postmortem chicken breast muscle to investigate changes in tenderness and effects on apo...In this study,endoplasmic reticulum(ER)stress inducer tunicamycin(TM)and inhibitor 4-phenylbutyric acid(4-PBA)were used to treat postmortem chicken breast muscle to investigate changes in tenderness and effects on apoptosis and autophagy during 5 days ageing.TM-induced ER stress reduced shear force,enhanced myofibril fragmentation index(MFI),disrupted myofibril structure,increased desmin degradation,and activatedμ-calpain and caspase-12.In addition,TM-induced ER stress increased the expression of Bax,Bim,and cytochrome c,and decreased the expression of Bcl-x L.Furthermore,TM-induced ER stress improved the conversion of LC3I to LC3II,raised the expression of Beclin-1,and decreased the expression of p62,PI3K,and m TOR.The opposite results were observed after 4-PBA treatment.These results suggested that ER stress could improve chicken tenderness,promote apoptosis and autophagy during chicken postmortem ageing.展开更多
Degenerative musculoskeletal diseases are structural and functional failures of the musculoskeletal system,including osteoarthritis,osteoporosis,intervertebral disc degeneration(IVDD),and sarcopenia.As the global popu...Degenerative musculoskeletal diseases are structural and functional failures of the musculoskeletal system,including osteoarthritis,osteoporosis,intervertebral disc degeneration(IVDD),and sarcopenia.As the global population ages,degenerative musculoskeletal diseases are becoming more prevalent.However,the pathogenesis of degenerative musculoskeletal diseases is not fully understood.Previous studies have revealed that endoplasmic reticulum(ER)stress is a stress response that occurs when impairment of the protein folding capacity of the ER leads to the accumulation of misfolded or unfolded proteins in the ER,contributing to degenerative musculoskeletal diseases.By affecting cartilage degeneration,synovitis,meniscal lesion,subchondral bone remodeling of osteoarthritis,bone remodeling and angiogenesis of osteoporosis,nucleus pulposus degeneration,annulus fibrosus rupture,cartilaginous endplate degeneration of IVDD,and sarcopenia,ER stress is involved in the pathogenesis of degenerative musculoskeletal diseases.Preclinical studies have found that regulation of ER stress can delay the progression of multiple degenerative musculoskeletal diseases.These pilot studies provide foundations for further evaluation of the feasibility,efficacy,and safety of ER stress modulators in the treatment of musculoskeletal degenerative diseases in clinical trials.In this review,we have integrated up-to-date research findings of ER stress into the pathogenesis of degenerative musculoskeletal diseases.In a future perspective,we have also discussed possible directions of ER stress in the investigation of degenerative musculoskeletal disease,potential therapeutic strategies for degenerative musculoskeletal diseases using ER stress modulators,as well as underlying challenges and obstacles in bench-to-beside research.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
BACKGROUND: The present study was undertaken to examine the regulatory effect of hydrogen sulfide(H2S) on endoplasmic reticulum stress in alveolar epithelial cells of rats with acute lung injury(ALI) induced by oleic ...BACKGROUND: The present study was undertaken to examine the regulatory effect of hydrogen sulfide(H2S) on endoplasmic reticulum stress in alveolar epithelial cells of rats with acute lung injury(ALI) induced by oleic acid(OA).METHODS: Seventy-two male Sprague Dawley(SD) rats were divided into control group, oleic acid-induced ALI group(OA group), oleic acid-induced ALI with sodium hydrosulfide(Na HS) pretreatment group(OA+Na HS group), and sodium hydrosulfide treatment group(Na HS group). Rats of each group were further subdivided into 3 subgroups. Index of quantitative assessment of histological lung injury(IQA), wet/dry weight ratio(W/D) and H2 S level of lung tissues were measured. The expressions of endoplasmic reticulum stress markers including glucose-regulated protein 78(GRP78) and α-subunit of eukaryotic translation initiation factor-2(el F2α) in lung tissues were measured by immunohistochemical staining and Western blotting.RESULTS: The IQA score and W/D ratio of lung tissues at the three time points significantly increased in rats injected with OA, but significantly decreased in other rats injected with OA and Na HS. The level of H2 S in lung tissue at the three time points significantly decreased in rats injected with OA, but significantly increased in other rats injected with both OA and Na HS. GRP78 and el F2α decreased in rats injected with OA, but increased in other rats injected with both OA and Na HS, especially at 4-hour and 6-hour time points.CONCLUSION: The results suggested that H2 S could promote alveolar epithelial cell endoplasmic reticulum stress in rats with ALI.展开更多
1 Introduction The endoplasmic reticulum(ER)serves many general functions,including the folding of membrane and secreted proteins and transport of the synthesized proteins,steroid production,lipid synthesis,glycogen s...1 Introduction The endoplasmic reticulum(ER)serves many general functions,including the folding of membrane and secreted proteins and transport of the synthesized proteins,steroid production,lipid synthesis,glycogen storage and production,and calcium homeostasis.Only properly folded proteins are transported from the rough展开更多
Foods and animal feeds frequently become contaminated with the nephrotoxic ochratoxin A(OTA).Our prior research has indicated that ursolic acid(UA),which is widely present in fruits and medicinal plants,has the potent...Foods and animal feeds frequently become contaminated with the nephrotoxic ochratoxin A(OTA).Our prior research has indicated that ursolic acid(UA),which is widely present in fruits and medicinal plants,has the potential to alleviate nephrotoxicity triggered by OTA.Additionally,excessive induction of endoplasmic reticulum(ER)-phagy exacerbates OTA-induced apoptosis.Therefore,further investigation is essential to comprehend whether UA can mitigate OTA-induced apoptosis by influencing ER-phagy.This objective is accomplished through a series of experiments involving assessments of cell viability,apoptosis,fluorescence microscopy,and western blot analysis.The outcomes of these experiments reveal that pre-treatment with 4μmol/L UA for 2 h can markedly reverse the elevated apoptotic rate,the co-localization of ER and lysosomes,and the protein expressions of GRP78,p-eIF2α,Chop,Bax,and Bak,as well as the reduced cell viability and the protein expressions of Lonp1,Trap1,p62,Tex264,FAM134B,Bcl-2,and Bcl-xl,all caused by exposure to 1μmol/L OTA for 24 h in human proximal tubule epithelial-originated kidney-2(HK-2)cells(P<0.05).Interestingly,the increased expression of LC3B-II induced by OTA is further amplified by UA pre-treatment(P<0.05).In conclusion,OTA triggers a harmful feedback loop between ER stress(ERS)and excessive ER-phagy,thereby further promoting ERS-and mitochondrial-mediated apoptosis in vitro.However,this effect is significantly mitigated by UA through the inhibition of autophagosome-lysosome fusion,consequently blocking the excessive ER-phagic flux.展开更多
Mucin 2(MUC2)is a critical component of the intestinal mucus barrier.Lactic acid bacteria(LAB)strains can improve mucosal homeostasis.In this study,we determined the expression of Muc2 induced by dead bacteria and cel...Mucin 2(MUC2)is a critical component of the intestinal mucus barrier.Lactic acid bacteria(LAB)strains can improve mucosal homeostasis.In this study,we determined the expression of Muc2 induced by dead bacteria and cell-free conditioned medium(CM)of 50 LAB strains in the human goblet cell line,LS174T.Dead bacteria or CM of LAB affected the Muc2 expression in a species-and strain-specific manner under homeostasis.Next,LAB strains with different regulatory abilities were selected,gavaged into mice,and exposed to dextran sodium sulfate(DSS)after 1 week.Different LAB strains inhibited intestinal injury to different degrees,with Lactobacillus acidophilus FCQHC4L1 exerting the most potent effect.FCQHC4L1 significantly decreased the secretion of pro-inflammatory factors,promoted the expression and secretion of mucin,and inhibited colitis development.This strain also regulated the gut microbiota and increased the secretion of butyric acid.Moreover,CM of FCQHC4L1 inhibited endoplasmic reticulum(ER)stress and ameliorated the abnormal expression of MUC2 by suppressing the activation of the GRP78/ATF6 and GRP78/IRE1/XBP1 signaling pathways.Our results highlight the potential of FCQHC4L1 as a therapeutic agent for strengthening the mucus barrier and improving the gut health.展开更多
Objectives This study examined the protective effect of salubrinal and the mechanism underlying this protection against tunicamycin （TM）- and hypoxia-induced apoptosis in rat cardiomyocytes. Methods Neonatal rat car...Objectives This study examined the protective effect of salubrinal and the mechanism underlying this protection against tunicamycin （TM）- and hypoxia-induced apoptosis in rat cardiomyocytes. Methods Neonatal rat cardiomyocytes were cultured from the ventricles of l-day-old Wistar rats. Cells were exposed to different concentrations of salubrinal （10, 20, and 40 gmol/L） for 30 min followed by TM treatment or hypoxia for 36 h. Apoptosis was measured by a multiparameter HCS （high content screening） apoptosis assay, TUNEL assay and flow cytometry. The phosphorylation of eukaryotic translation initiation factor 2 subunit alpha （eIF2c0 and the expression of cleaved caspase-12 were determined by Western blotting. C/EBP homologous protein （CHOP） was detected by immunocytochemistry. Results HCS, TUNEL assays and flow cytometry showed that salubrinal protected cardiomyocytes against apoptosis induced by TM or hypoxia. Western blotting showed that salubrinal protected cardiomyocytes against apoptosis by inducing eIF2ct phosphorylation and down-regulating the expression of the endoplasmic reticulum stress-mediated apoptotic proteins, CHOP and cleaved caspase-12. Conclusions Our study suggests that salubrinal protects rat cardiomyocytes against TM- or hypoxia-associated apoptosis via a mechanism involving the inhibition of ER stress-mediated apoptosis.展开更多
BACKGROUND:To determine the protective role of mesencephalic astrocyte-derived neurotrophic factor(MANF) in regulating sepsis-associated acute kidney injury(S-AKI).METHODS:A total of 96 mice were randomly divided into...BACKGROUND:To determine the protective role of mesencephalic astrocyte-derived neurotrophic factor(MANF) in regulating sepsis-associated acute kidney injury(S-AKI).METHODS:A total of 96 mice were randomly divided into the control group,control+MANF group,S-AKI group,and S-AKI+MANF group.The S-AKI model was established by injecting lipopolysaccharide(LPS) at 10 mg/kg intraperitoneally.MANF(200 μg/kg) was administered to the control+MANF and S-AKI+MANF groups.An equal dose of normal saline was administered daily intraperitoneally in the control and S-AKI groups.Serum and kidney tissue samples were obtained for biochemical analysis.Western blotting was used to detect the protein expression of MANF in the kidney,and enzyme-linked immunosorbent assay(ELISA) was used to determine expression of MANF in the serum,pro-inflammatory cytokines(tumor necrosis factor-α [TNF-α] and interleukin-6 [IL-6]).Serum creatinine(SCr),and blood urea nitrogen(BUN)were examined using an automatic biochemical analyzer.In addition,the kidney tissue was observed for pathological changes by hematoxylin-eosin staining.The comparison between two groups was performed by unpaired Student’s t-test,and statistics among multiple groups were carried out using Tukey’s post hoc test following one-way analysis of variance(ANOVA).A P-value <0.05 was considered statistically significant.RESULTS:At the early stage of S-AKI,MANF in the kidney tissue was up-regulated,but with the development of the disease,it was down-regulated.Renal function was worsened in the S-AKI group,and TNF-α and IL-6 were elevated.The administration of MANF significantly alleviated the elevated levels of SCr and BUN and inhibited the expression of TNF-α and IL-6 in the kidney.The pathological changes were more extensive in the S-AKI group than in the S-AKI+MANF group.CONCLUSION:MANF treatment may significantly alleviate renal injury,reduce the inflammatory response,and alleviate or reverse kidney tissue damage.MANF may have a protective effect on S-AKI,suggesting a potential treatment for S-AKI.展开更多
Theaflavins from black tea effectively improve insulin secretion in obesity and diabetes,but the molecular mechanisms are unclear.Here,the palmitic acid(PA)-induced pancreaticβ-TC-6 cells and high fat-/high glucose-i...Theaflavins from black tea effectively improve insulin secretion in obesity and diabetes,but the molecular mechanisms are unclear.Here,the palmitic acid(PA)-induced pancreaticβ-TC-6 cells and high fat-/high glucose-induced zebrafish were used.The effects of theaflavin-3,3'-digallate(TF3)on glucolipotoxicityinduced insulin secretion dysfunction,ferroptosis and endoplasmic reticulum(ER)stress were investigated by a variety of molecular biological approaches,inductively coupled plasma-mass spectrometry(ICP-MS),transmission electron microscopy(TEM)and widely targeted metabolomics analysis.TF3 was found to potently inhibit glucolipotoxicity-induced insulin secretion dysfunction and ferroptosis inβ-TC-6 cells and zebrafish,with increasing glutathione peroxidase 4(GPX4)expression,suppressing lipid peroxidation and iron accumulation and protecting mitochondria.Additionally,TF3 attenuated ER stress by regulating 3 unfolded protein response(UPR)pathways inβ-TC-6 cells,and significantly modulated linoleic acid metabolism and L-kynurenine signalling in zebrafish.The expression of sarcoplasmic/endoplasmic reticulum calcium ATPase 2(SERCA2)was obviously enhanced by TF3.Thapsigargin,a SERCA2 inhibitor,remarkably reversed the effects of TF3 on insulin production,ferroptosis,ER stress and the kynurenine signalling.Together,this work revealed the critical role of SERCA2 in ferroptosis regulation,and demonstrated TF3 targeted SERCA2 to inhibit ER stress and ferropto sis,thereby protectingβ-cell secretory function from glucolipotoxicity.展开更多
基金supported by the National Natural Science Foundation of China(G32072142,31972099)。
文摘In this study,endoplasmic reticulum(ER)stress inducer tunicamycin(TM)and inhibitor 4-phenylbutyric acid(4-PBA)were used to treat postmortem chicken breast muscle to investigate changes in tenderness and effects on apoptosis and autophagy during 5 days ageing.TM-induced ER stress reduced shear force,enhanced myofibril fragmentation index(MFI),disrupted myofibril structure,increased desmin degradation,and activatedμ-calpain and caspase-12.In addition,TM-induced ER stress increased the expression of Bax,Bim,and cytochrome c,and decreased the expression of Bcl-x L.Furthermore,TM-induced ER stress improved the conversion of LC3I to LC3II,raised the expression of Beclin-1,and decreased the expression of p62,PI3K,and m TOR.The opposite results were observed after 4-PBA treatment.These results suggested that ER stress could improve chicken tenderness,promote apoptosis and autophagy during chicken postmortem ageing.
基金supported by the National Natural Science Foundation of China(92268115,82072506,81874030,82172387,82372371,82371989)the Science and Technology Innovation Program of Hunan Province(2021RC3025)+3 种基金the Natural Science Foundation of Jiangsu Province(BK20230066)the Suzhou Science and Technology Development Plan(SKY2023035,SZM2023008)the Gusu Health Talents Program(GSWS2020023)the Innovation Project for Postgraduate Students of Central South University(1053320221391,1053320231273).
文摘Degenerative musculoskeletal diseases are structural and functional failures of the musculoskeletal system,including osteoarthritis,osteoporosis,intervertebral disc degeneration(IVDD),and sarcopenia.As the global population ages,degenerative musculoskeletal diseases are becoming more prevalent.However,the pathogenesis of degenerative musculoskeletal diseases is not fully understood.Previous studies have revealed that endoplasmic reticulum(ER)stress is a stress response that occurs when impairment of the protein folding capacity of the ER leads to the accumulation of misfolded or unfolded proteins in the ER,contributing to degenerative musculoskeletal diseases.By affecting cartilage degeneration,synovitis,meniscal lesion,subchondral bone remodeling of osteoarthritis,bone remodeling and angiogenesis of osteoporosis,nucleus pulposus degeneration,annulus fibrosus rupture,cartilaginous endplate degeneration of IVDD,and sarcopenia,ER stress is involved in the pathogenesis of degenerative musculoskeletal diseases.Preclinical studies have found that regulation of ER stress can delay the progression of multiple degenerative musculoskeletal diseases.These pilot studies provide foundations for further evaluation of the feasibility,efficacy,and safety of ER stress modulators in the treatment of musculoskeletal degenerative diseases in clinical trials.In this review,we have integrated up-to-date research findings of ER stress into the pathogenesis of degenerative musculoskeletal diseases.In a future perspective,we have also discussed possible directions of ER stress in the investigation of degenerative musculoskeletal disease,potential therapeutic strategies for degenerative musculoskeletal diseases using ER stress modulators,as well as underlying challenges and obstacles in bench-to-beside research.
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BACKGROUND: The present study was undertaken to examine the regulatory effect of hydrogen sulfide(H2S) on endoplasmic reticulum stress in alveolar epithelial cells of rats with acute lung injury(ALI) induced by oleic acid(OA).METHODS: Seventy-two male Sprague Dawley(SD) rats were divided into control group, oleic acid-induced ALI group(OA group), oleic acid-induced ALI with sodium hydrosulfide(Na HS) pretreatment group(OA+Na HS group), and sodium hydrosulfide treatment group(Na HS group). Rats of each group were further subdivided into 3 subgroups. Index of quantitative assessment of histological lung injury(IQA), wet/dry weight ratio(W/D) and H2 S level of lung tissues were measured. The expressions of endoplasmic reticulum stress markers including glucose-regulated protein 78(GRP78) and α-subunit of eukaryotic translation initiation factor-2(el F2α) in lung tissues were measured by immunohistochemical staining and Western blotting.RESULTS: The IQA score and W/D ratio of lung tissues at the three time points significantly increased in rats injected with OA, but significantly decreased in other rats injected with OA and Na HS. The level of H2 S in lung tissue at the three time points significantly decreased in rats injected with OA, but significantly increased in other rats injected with both OA and Na HS. GRP78 and el F2α decreased in rats injected with OA, but increased in other rats injected with both OA and Na HS, especially at 4-hour and 6-hour time points.CONCLUSION: The results suggested that H2 S could promote alveolar epithelial cell endoplasmic reticulum stress in rats with ALI.
文摘1 Introduction The endoplasmic reticulum(ER)serves many general functions,including the folding of membrane and secreted proteins and transport of the synthesized proteins,steroid production,lipid synthesis,glycogen storage and production,and calcium homeostasis.Only properly folded proteins are transported from the rough
基金financially supported by the National Natural Science Foundation of China(82060598,32260587)the Natural Science Foundation of Guizhou Province(QKH-J-ZK[2021]181)+4 种基金the Scientific Research Program of Guizhou Provincial Department of Education(QJJ[2023]019)the Science&Technology Program of Guizhou Province(QKHPTRC-CXTD[2022]014)the Excellent Youth Talents of Zunyi Medical University(17zy-006)the Innovation and Entrepreneurship Training Program for College Students of Guizhou Province(S202210661138)the Innovation and Entrepreneurship Training Program for College Students of Zunyi Medical University(ZYDC2021108)。
文摘Foods and animal feeds frequently become contaminated with the nephrotoxic ochratoxin A(OTA).Our prior research has indicated that ursolic acid(UA),which is widely present in fruits and medicinal plants,has the potential to alleviate nephrotoxicity triggered by OTA.Additionally,excessive induction of endoplasmic reticulum(ER)-phagy exacerbates OTA-induced apoptosis.Therefore,further investigation is essential to comprehend whether UA can mitigate OTA-induced apoptosis by influencing ER-phagy.This objective is accomplished through a series of experiments involving assessments of cell viability,apoptosis,fluorescence microscopy,and western blot analysis.The outcomes of these experiments reveal that pre-treatment with 4μmol/L UA for 2 h can markedly reverse the elevated apoptotic rate,the co-localization of ER and lysosomes,and the protein expressions of GRP78,p-eIF2α,Chop,Bax,and Bak,as well as the reduced cell viability and the protein expressions of Lonp1,Trap1,p62,Tex264,FAM134B,Bcl-2,and Bcl-xl,all caused by exposure to 1μmol/L OTA for 24 h in human proximal tubule epithelial-originated kidney-2(HK-2)cells(P<0.05).Interestingly,the increased expression of LC3B-II induced by OTA is further amplified by UA pre-treatment(P<0.05).In conclusion,OTA triggers a harmful feedback loop between ER stress(ERS)and excessive ER-phagy,thereby further promoting ERS-and mitochondrial-mediated apoptosis in vitro.However,this effect is significantly mitigated by UA through the inhibition of autophagosome-lysosome fusion,consequently blocking the excessive ER-phagic flux.
基金funded by the Guangdong Province Key Research and Development Project(2022B111107006)the National Natural Science Foundation of China(32021005 and 31820103010)the Fundamental Research Funds for the Central Universities(JUSRP622013)。
文摘Mucin 2(MUC2)is a critical component of the intestinal mucus barrier.Lactic acid bacteria(LAB)strains can improve mucosal homeostasis.In this study,we determined the expression of Muc2 induced by dead bacteria and cell-free conditioned medium(CM)of 50 LAB strains in the human goblet cell line,LS174T.Dead bacteria or CM of LAB affected the Muc2 expression in a species-and strain-specific manner under homeostasis.Next,LAB strains with different regulatory abilities were selected,gavaged into mice,and exposed to dextran sodium sulfate(DSS)after 1 week.Different LAB strains inhibited intestinal injury to different degrees,with Lactobacillus acidophilus FCQHC4L1 exerting the most potent effect.FCQHC4L1 significantly decreased the secretion of pro-inflammatory factors,promoted the expression and secretion of mucin,and inhibited colitis development.This strain also regulated the gut microbiota and increased the secretion of butyric acid.Moreover,CM of FCQHC4L1 inhibited endoplasmic reticulum(ER)stress and ameliorated the abnormal expression of MUC2 by suppressing the activation of the GRP78/ATF6 and GRP78/IRE1/XBP1 signaling pathways.Our results highlight the potential of FCQHC4L1 as a therapeutic agent for strengthening the mucus barrier and improving the gut health.
基金This study was supported by the Ministry Science Foundation of the Chinese People's Liberation Army during the 12th Five-Year Plan Period
文摘Objectives This study examined the protective effect of salubrinal and the mechanism underlying this protection against tunicamycin （TM）- and hypoxia-induced apoptosis in rat cardiomyocytes. Methods Neonatal rat cardiomyocytes were cultured from the ventricles of l-day-old Wistar rats. Cells were exposed to different concentrations of salubrinal （10, 20, and 40 gmol/L） for 30 min followed by TM treatment or hypoxia for 36 h. Apoptosis was measured by a multiparameter HCS （high content screening） apoptosis assay, TUNEL assay and flow cytometry. The phosphorylation of eukaryotic translation initiation factor 2 subunit alpha （eIF2c0 and the expression of cleaved caspase-12 were determined by Western blotting. C/EBP homologous protein （CHOP） was detected by immunocytochemistry. Results HCS, TUNEL assays and flow cytometry showed that salubrinal protected cardiomyocytes against apoptosis induced by TM or hypoxia. Western blotting showed that salubrinal protected cardiomyocytes against apoptosis by inducing eIF2ct phosphorylation and down-regulating the expression of the endoplasmic reticulum stress-mediated apoptotic proteins, CHOP and cleaved caspase-12. Conclusions Our study suggests that salubrinal protects rat cardiomyocytes against TM- or hypoxia-associated apoptosis via a mechanism involving the inhibition of ER stress-mediated apoptosis.
基金supported by the Health Commission Clinical Characteristic Discipline Construction Program of Pudong New Area,Shanghai (PW Yts2021-17)Youth Science and Technology Project Health and Family Planning Commission of Pudong New Area,Shanghai (PWRq2020-35)。
文摘BACKGROUND:To determine the protective role of mesencephalic astrocyte-derived neurotrophic factor(MANF) in regulating sepsis-associated acute kidney injury(S-AKI).METHODS:A total of 96 mice were randomly divided into the control group,control+MANF group,S-AKI group,and S-AKI+MANF group.The S-AKI model was established by injecting lipopolysaccharide(LPS) at 10 mg/kg intraperitoneally.MANF(200 μg/kg) was administered to the control+MANF and S-AKI+MANF groups.An equal dose of normal saline was administered daily intraperitoneally in the control and S-AKI groups.Serum and kidney tissue samples were obtained for biochemical analysis.Western blotting was used to detect the protein expression of MANF in the kidney,and enzyme-linked immunosorbent assay(ELISA) was used to determine expression of MANF in the serum,pro-inflammatory cytokines(tumor necrosis factor-α [TNF-α] and interleukin-6 [IL-6]).Serum creatinine(SCr),and blood urea nitrogen(BUN)were examined using an automatic biochemical analyzer.In addition,the kidney tissue was observed for pathological changes by hematoxylin-eosin staining.The comparison between two groups was performed by unpaired Student’s t-test,and statistics among multiple groups were carried out using Tukey’s post hoc test following one-way analysis of variance(ANOVA).A P-value <0.05 was considered statistically significant.RESULTS:At the early stage of S-AKI,MANF in the kidney tissue was up-regulated,but with the development of the disease,it was down-regulated.Renal function was worsened in the S-AKI group,and TNF-α and IL-6 were elevated.The administration of MANF significantly alleviated the elevated levels of SCr and BUN and inhibited the expression of TNF-α and IL-6 in the kidney.The pathological changes were more extensive in the S-AKI group than in the S-AKI+MANF group.CONCLUSION:MANF treatment may significantly alleviate renal injury,reduce the inflammatory response,and alleviate or reverse kidney tissue damage.MANF may have a protective effect on S-AKI,suggesting a potential treatment for S-AKI.
基金supported by National Natural Science Foundation of China(32272303)Natural Science Foundation of Zhejiang Province,China(LY21C200010)。
文摘Theaflavins from black tea effectively improve insulin secretion in obesity and diabetes,but the molecular mechanisms are unclear.Here,the palmitic acid(PA)-induced pancreaticβ-TC-6 cells and high fat-/high glucose-induced zebrafish were used.The effects of theaflavin-3,3'-digallate(TF3)on glucolipotoxicityinduced insulin secretion dysfunction,ferroptosis and endoplasmic reticulum(ER)stress were investigated by a variety of molecular biological approaches,inductively coupled plasma-mass spectrometry(ICP-MS),transmission electron microscopy(TEM)and widely targeted metabolomics analysis.TF3 was found to potently inhibit glucolipotoxicity-induced insulin secretion dysfunction and ferroptosis inβ-TC-6 cells and zebrafish,with increasing glutathione peroxidase 4(GPX4)expression,suppressing lipid peroxidation and iron accumulation and protecting mitochondria.Additionally,TF3 attenuated ER stress by regulating 3 unfolded protein response(UPR)pathways inβ-TC-6 cells,and significantly modulated linoleic acid metabolism and L-kynurenine signalling in zebrafish.The expression of sarcoplasmic/endoplasmic reticulum calcium ATPase 2(SERCA2)was obviously enhanced by TF3.Thapsigargin,a SERCA2 inhibitor,remarkably reversed the effects of TF3 on insulin production,ferroptosis,ER stress and the kynurenine signalling.Together,this work revealed the critical role of SERCA2 in ferroptosis regulation,and demonstrated TF3 targeted SERCA2 to inhibit ER stress and ferropto sis,thereby protectingβ-cell secretory function from glucolipotoxicity.
