Temozolomide(TMZ)resistance is a major obstacle in glioma treatment.Nuclear protein-1(NUPR1)is a regulator of glioma progression.This study investigated the mechanism of NUPR1 in TMZ resistance in hypoxiatreated gliom...Temozolomide(TMZ)resistance is a major obstacle in glioma treatment.Nuclear protein-1(NUPR1)is a regulator of glioma progression.This study investigated the mechanism of NUPR1 in TMZ resistance in hypoxiatreated glioma cells and its mechanism in modulating autophagy.We treated TMZ-resistant cells U251-TMZ and T98G-TMZ to normoxia or hypoxia and silenced NUPR1 in hypoxia-treated U251-TMZ and T98G-TMZ cells to assess cell viability,proliferation,apoptosis,LC3-II/LC3-I and p62 expressions,and autophagic flux under different concentrations of TMZ.We found that hypoxia upregulated NUPR1 expression and autophagy while NUPR1 silencing suppressed hypoxia-induced TMZ resistance and autophagy in glioma cells.We also investigated the interaction between NUPR1 and lysine demethylase 3A(KDM3A),as well as the enrichments of KDM3A and H3 lysine 9 dimethylation(H3K9me2)in the transcription factor EB(TFEB)promoter region.Our results suggest that hypoxia-induced NUPR1 promotes TFEB transcription by binding to KDM3A and reducing H3K9me2 levels,thereby augmenting glioma cell autophagy and TMZ resistance.Moreover,the overexpression of KDM3A or TFEB promoted glioma cell autophagy.In a xenograft tumor model,silencing NUPR1 suppressed TMZ resistance in glioma cells in vivo.Overall,our findings highlight a mechanism by which NUPR1 enhances glioma cell autophagy and TMZ resistance via the KDM3A/TFEB axis.展开更多
Objective:To examine the effect of quercetin on stereological parameters and autophagy-related genes in ovaries of polycystic ovary syndrome(PCOS)rats.Methods:Fifty female Sprague-Dawley rats were randomly divided int...Objective:To examine the effect of quercetin on stereological parameters and autophagy-related genes in ovaries of polycystic ovary syndrome(PCOS)rats.Methods:Fifty female Sprague-Dawley rats were randomly divided into five groups:the control group,the ethanol group,the quercetin group(15 mg/kg/day),the PCOS group,as well as the PCOS+quercetin group.After the induction of PCOS,quercetin was administered orally for 30 days.Histological,stereological and real-time PCR analyses were carried out to evaluate the effect of quercetin on PCOS rats.Results:Stereological analysis revealed that quercetin significantly increased the number of ovarian follicles and the volume of corpus luteum and induced a significant decrease in atretic follicles in comparison to the PCOS group.In addition,quercetin markedly increased mTOR gene expression while decreasing Beclin-1 and LC3 gene expression.Conclusions:Quercetin strongly modulates the expression of ovarian autophagy-related genes and stereological parameters in PCOS rats.Therefore,it can be considered as an ameliorative component for ovarian follicular impairments.展开更多
AbstracBteclin-1 is the firstly-identified mammalian protein of the autophagy machinery,which functions as a molecular scaffold for the assembly of PI3KC3(class II phosphatidylinositol 3 kinase)complex,thus controllin...AbstracBteclin-1 is the firstly-identified mammalian protein of the autophagy machinery,which functions as a molecular scaffold for the assembly of PI3KC3(class II phosphatidylinositol 3 kinase)complex,thus controlling autophagy induction and other cellular trafficking events.Notably,there is mounting evidence establishing the implications of Beclin-1 in diverse tumorigenesis processes,including tumor suppression and progression as well as resistance to cancer therapeutics and CSC(cancer stem-like cell)maintenance.More importantly,Beclin-1 has been confirmed as a potential target for the treatment of multiple cancers.In this review,we provide a comprehensive survey of the structure,functions,and regulations of Beclin-1,and we discuss recent advances in understanding the controversial roles of Beclin-1 in oncology.Moreover,we focus on summarizing the targeted Beclin-1-regulating strategies in cancer therapy,providing novel insights into a promising strategy for regulating Beclin-1 to improvecancer therapeutics in thefuture.展开更多
Quercetin can reverse high glucose-induced inhibition of neural cell proliferation, and therefore may have a neuroprotective effect in diabetic peripheral neuropathy. It is difficult to obtain pri- mary Schwann cells ...Quercetin can reverse high glucose-induced inhibition of neural cell proliferation, and therefore may have a neuroprotective effect in diabetic peripheral neuropathy. It is difficult to obtain pri- mary Schwann cells and RSC96 cells could replace primary Schwann cells in studies of the role of autophagy in the mechanism underlying diabetic peripheral neuropathy. Here, we show that under high glucose conditions, there are fewer autophagosomes in immortalized rat RSC96 cells and primary rat Schwann ceils than under control conditions, the proliferative activity of both cell types is significantly impaired, and the expression of Berlin- 1 and LC3, the molecular mark- ers for autophagy, is significantly lower. After intervention with quercetin, the autophagic and proliferative activity of both cell types is rescued. These results suggest that quercetin can allevi- ate high glucose-induced damage to Schwann cells by autophagy.展开更多
Autophagy is a conserved and programmed catabolic process that degrades damaged pro- teins and organelles. But the underlying mechanism and functions of autophagy in the ische- mia-reperfusion （IR）-induced injury ar...Autophagy is a conserved and programmed catabolic process that degrades damaged pro- teins and organelles. But the underlying mechanism and functions of autophagy in the ische- mia-reperfusion （IR）-induced injury are unknown. In this study, we employed simulated IR of N2a cells as an in vitro model of IR injury to the neurons and monitored autophagic processes. It was found that the levels of Beclin-1 （a key molecule of autophay complex, Beclin-1/elass III PI3K） and LC-3 II （an autophagy marker） were remarkably increased with time during the process of ischemia and the process of reperfusion after 90 min of ischemia, while the protein kinases pTOS6K and roTOR which are involved in autophagy regulation showed delayed inactivation after reperfusion. Admini- stration of 3-methyladenine （3MA）, an inhibitor of class III PI3K, abolished autophagy during reper- fusion, while employment of rapamycin, an inhibitor of mTORC1 （normally inducing autophagy）, surprisingly weakened the induction of autophagy during reperfusion. Analyses of mitochondria function by relative cell viability demonstrated that autophagy inhibition by 3-MA attenuated the de- cline of mitochondria function during reperfusion. Our data demonstrated that there were two distinct dynamic patterns of autophagy during IR-induced N2a injury, Beclin-1/class III PI3K com- plex-dependent and mTORCl-dependent. Inhibition of over-autophagy improved cell survival. These suggest that targeting autophagy therapy will be a novel strategy to control IR-induced neuronal damage.展开更多
Methylprednisolone markedly reduces autophagy and apoptosis after secondary spinal cord injury. Here, we investigated whether pretreatment of cells with methylprednisolone would protect neuron-like cells from subseque...Methylprednisolone markedly reduces autophagy and apoptosis after secondary spinal cord injury. Here, we investigated whether pretreatment of cells with methylprednisolone would protect neuron-like cells from subsequent oxidative damage via suppression of autophagy and apoptosis. Cultured N2 a cells were pretreated with 10 μM methylprednisolone for 30 minutes, then exposed to 100 μM H2O2 for 24 hours. Inverted phase contrast microscope images, MTT assay, flow cytometry and western blot results showed that, compared to cells exposed to 100 μM H2O2 alone, cells pretreated with methylprednisolone had a significantly lower percentage of apoptotic cells, maintained a healthy morphology, and showed downregulation of autophagic protein light chain 3B and Beclin-1 protein expression. These findings indicate that methylprednisolone exerted neuroprotective effects against oxidative damage by suppressing autophagy and apoptosis.展开更多
Background:The role of autophagy in the formation of hypertrophic scars(HS)remains unclear.This study aimed to explore the role and potential mechanism of autophagy during the development of HS.Methods:RNA and protein...Background:The role of autophagy in the formation of hypertrophic scars(HS)remains unclear.This study aimed to explore the role and potential mechanism of autophagy during the development of HS.Methods:RNA and protein expression levels of Beclin-1,p62,and LC3II in normal skin tissues and HS specimens from different patients were examined.Autophagy inducers and inhibitors were used to cure established HS in rabbit ears,and the expression of Beclin-1,p62,and LC3II at the RNA and protein level was determined.Lastly,the effects of autophagy inducers and inhibitors on HS development were analyzed.Results:Compared to normal skin tissues,the expression of LC3II and Beclin-1 was higher(P<0.05),while that of p62 was lower(P<0.05)in HS tissues.In addition,the LC3II/LC3I ratio was increased during HS formation,and the altered expression of the three proteins stabilized after one year.Administration of autophagy inducers enhanced the formation of HS as well as the expression levels of LC3II and Beclin-1 but decreased p62 expression.Meanwhile,administration of autophagy inhibitors increased the expression of LC3II,Beclin-1,and p62,along with reduced HS formation.Conclusion:Autophagic activity increased during HS initiation and subsequent stabilization.In addition,autophagy inhibitors were able to inhibit HS formation by suppressing autophagy,whereas autophagy inducers promoted scar hyperplasia by enhancing autophagy。展开更多
Secondary damage is a critical determinant of the functional outcome in patients with spinal cord injury （SCI）, and involves multiple mechanisms of which the most important is the loss of nerve cells mediated by mul...Secondary damage is a critical determinant of the functional outcome in patients with spinal cord injury （SCI）, and involves multiple mechanisms of which the most important is the loss of nerve cells mediated by multiple factors. Autophagy can result in cell death, and plays a key role in the development of SCI. It has been recognized that valproic acid （VPA） is neuroprotective in certain experimental animal models, however, the levels of autophagic changes in the process of neuroprotection by VPA treatment following SCI are still unknown. In the present study, we determined the extent of autophagy after VPA treatment in a rat model of SCI. We found that both the mRNA and protein levels of Beclin-1 and LC3 were significantly increased at 1, 2, and 6 h after SCI and peaked at 2 h; however, Western blot showed that autophagy was markedly decreased by VPA treatment at 2 h post-injury. Besides, post-SCI treatment with VPA improved the Basso-Beattie-Bresnahan scale, increased the number of ventral horn motoneurons, and reduced myelin sheath damage compared with vehicle-treated animals at 42 days after SCI. Together, our results demonstrated the characteristics of autophagy expression following SCI, and foundthat VPA reduced autophagy and enhanced motor function.展开更多
In a normal prostate,the process of controling cell death is essential to maintain tissue homeostasis and its inhibition may lead to the development of cancer.Androgen receptor signaling plays pivotal roles in the pro...In a normal prostate,the process of controling cell death is essential to maintain tissue homeostasis and its inhibition may lead to the development of cancer.Androgen receptor signaling plays pivotal roles in the prostate development and homeostasis as well as in the progression of prostate cancer.The main treatment for prostate cancer is a combination of androgen deprivation therapy(ADT)using anti-androgens and docetaxil administration.However,ADT eventually fails due to a pathological unbalance of cell death processes,in particular apoptosis and autophagy.As a result prostate tumors may re-grow and progress into the castration resistant stage.The role of autophagy in tumorigenesis is complex and it could be a double-edged sword process,as autophagy defects promote cancer progression in association with various dangerous cellular processes,while functional autophagy enables cancer cell survival under stress and likely contributes to the resistance of treatment.Autophagy is often impaired in prostate cancer,due to either activation of the Akt/mTOR pathway,which normally inhibits autophagy,or through allelic loss of Beclin-1(BECN1),an essential autophagy gene.In particular,elucidating the interplay between autophagy and tumor cell metabolism will provide unique opportunities to identify new therapeutic targets and to develop synthetically lethal treatment strategies that preferentially target cancer cells,while sparing normal tissues.展开更多
基金supported by Scientific Research Project of Education Department of Liaoning Province(Grant Number LJKZ0854).
文摘Temozolomide(TMZ)resistance is a major obstacle in glioma treatment.Nuclear protein-1(NUPR1)is a regulator of glioma progression.This study investigated the mechanism of NUPR1 in TMZ resistance in hypoxiatreated glioma cells and its mechanism in modulating autophagy.We treated TMZ-resistant cells U251-TMZ and T98G-TMZ to normoxia or hypoxia and silenced NUPR1 in hypoxia-treated U251-TMZ and T98G-TMZ cells to assess cell viability,proliferation,apoptosis,LC3-II/LC3-I and p62 expressions,and autophagic flux under different concentrations of TMZ.We found that hypoxia upregulated NUPR1 expression and autophagy while NUPR1 silencing suppressed hypoxia-induced TMZ resistance and autophagy in glioma cells.We also investigated the interaction between NUPR1 and lysine demethylase 3A(KDM3A),as well as the enrichments of KDM3A and H3 lysine 9 dimethylation(H3K9me2)in the transcription factor EB(TFEB)promoter region.Our results suggest that hypoxia-induced NUPR1 promotes TFEB transcription by binding to KDM3A and reducing H3K9me2 levels,thereby augmenting glioma cell autophagy and TMZ resistance.Moreover,the overexpression of KDM3A or TFEB promoted glioma cell autophagy.In a xenograft tumor model,silencing NUPR1 suppressed TMZ resistance in glioma cells in vivo.Overall,our findings highlight a mechanism by which NUPR1 enhances glioma cell autophagy and TMZ resistance via the KDM3A/TFEB axis.
基金This work was supported by the Shiraz University of Medical Sciences(grant number:10774).
文摘Objective:To examine the effect of quercetin on stereological parameters and autophagy-related genes in ovaries of polycystic ovary syndrome(PCOS)rats.Methods:Fifty female Sprague-Dawley rats were randomly divided into five groups:the control group,the ethanol group,the quercetin group(15 mg/kg/day),the PCOS group,as well as the PCOS+quercetin group.After the induction of PCOS,quercetin was administered orally for 30 days.Histological,stereological and real-time PCR analyses were carried out to evaluate the effect of quercetin on PCOS rats.Results:Stereological analysis revealed that quercetin significantly increased the number of ovarian follicles and the volume of corpus luteum and induced a significant decrease in atretic follicles in comparison to the PCOS group.In addition,quercetin markedly increased mTOR gene expression while decreasing Beclin-1 and LC3 gene expression.Conclusions:Quercetin strongly modulates the expression of ovarian autophagy-related genes and stereological parameters in PCOS rats.Therefore,it can be considered as an ameliorative component for ovarian follicular impairments.
基金supported by the National Natural Science Foundation of China(Grant Nos.22177084 and 82173666)Sichuan Science and Technology Program(Grant No.2022YFQ0054,China)the Open Research Fund of Chengdu University of Traditional Chinese Medicine State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China.
文摘AbstracBteclin-1 is the firstly-identified mammalian protein of the autophagy machinery,which functions as a molecular scaffold for the assembly of PI3KC3(class II phosphatidylinositol 3 kinase)complex,thus controlling autophagy induction and other cellular trafficking events.Notably,there is mounting evidence establishing the implications of Beclin-1 in diverse tumorigenesis processes,including tumor suppression and progression as well as resistance to cancer therapeutics and CSC(cancer stem-like cell)maintenance.More importantly,Beclin-1 has been confirmed as a potential target for the treatment of multiple cancers.In this review,we provide a comprehensive survey of the structure,functions,and regulations of Beclin-1,and we discuss recent advances in understanding the controversial roles of Beclin-1 in oncology.Moreover,we focus on summarizing the targeted Beclin-1-regulating strategies in cancer therapy,providing novel insights into a promising strategy for regulating Beclin-1 to improvecancer therapeutics in thefuture.
基金supported by the National Natural Science Foundation of China,No.30572438the Beijing Science Nuture Foundation,No.7132189a grant from Science Foundation of Peking Union Medical College Hospital,No.2013-098
文摘Quercetin can reverse high glucose-induced inhibition of neural cell proliferation, and therefore may have a neuroprotective effect in diabetic peripheral neuropathy. It is difficult to obtain pri- mary Schwann cells and RSC96 cells could replace primary Schwann cells in studies of the role of autophagy in the mechanism underlying diabetic peripheral neuropathy. Here, we show that under high glucose conditions, there are fewer autophagosomes in immortalized rat RSC96 cells and primary rat Schwann ceils than under control conditions, the proliferative activity of both cell types is significantly impaired, and the expression of Berlin- 1 and LC3, the molecular mark- ers for autophagy, is significantly lower. After intervention with quercetin, the autophagic and proliferative activity of both cell types is rescued. These results suggest that quercetin can allevi- ate high glucose-induced damage to Schwann cells by autophagy.
基金supported by grants from the Graduate Programs Foundation of Ministry of Education of China(No.20070487101)Postdoctoral Foundation of China(No.20090450216)
文摘Autophagy is a conserved and programmed catabolic process that degrades damaged pro- teins and organelles. But the underlying mechanism and functions of autophagy in the ische- mia-reperfusion （IR）-induced injury are unknown. In this study, we employed simulated IR of N2a cells as an in vitro model of IR injury to the neurons and monitored autophagic processes. It was found that the levels of Beclin-1 （a key molecule of autophay complex, Beclin-1/elass III PI3K） and LC-3 II （an autophagy marker） were remarkably increased with time during the process of ischemia and the process of reperfusion after 90 min of ischemia, while the protein kinases pTOS6K and roTOR which are involved in autophagy regulation showed delayed inactivation after reperfusion. Admini- stration of 3-methyladenine （3MA）, an inhibitor of class III PI3K, abolished autophagy during reper- fusion, while employment of rapamycin, an inhibitor of mTORC1 （normally inducing autophagy）, surprisingly weakened the induction of autophagy during reperfusion. Analyses of mitochondria function by relative cell viability demonstrated that autophagy inhibition by 3-MA attenuated the de- cline of mitochondria function during reperfusion. Our data demonstrated that there were two distinct dynamic patterns of autophagy during IR-induced N2a injury, Beclin-1/class III PI3K com- plex-dependent and mTORCl-dependent. Inhibition of over-autophagy improved cell survival. These suggest that targeting autophagy therapy will be a novel strategy to control IR-induced neuronal damage.
基金supported by the National Natural Science Foundation of China,No.81171799,81471854the Science and Technology Research Project of Education Department of Liaoning Province of China,No.L2013333+1 种基金the"College Students’Science and Technology Innovation Project"of Liaoning Medical University Principal Fund-Aohong Boze Fund of China,No.2014D08the Liaoning Medical University Principal Fund-Aohong Boze Graduate Student Science Research Innovation Fund,No.AH2014017
文摘Methylprednisolone markedly reduces autophagy and apoptosis after secondary spinal cord injury. Here, we investigated whether pretreatment of cells with methylprednisolone would protect neuron-like cells from subsequent oxidative damage via suppression of autophagy and apoptosis. Cultured N2 a cells were pretreated with 10 μM methylprednisolone for 30 minutes, then exposed to 100 μM H2O2 for 24 hours. Inverted phase contrast microscope images, MTT assay, flow cytometry and western blot results showed that, compared to cells exposed to 100 μM H2O2 alone, cells pretreated with methylprednisolone had a significantly lower percentage of apoptotic cells, maintained a healthy morphology, and showed downregulation of autophagic protein light chain 3B and Beclin-1 protein expression. These findings indicate that methylprednisolone exerted neuroprotective effects against oxidative damage by suppressing autophagy and apoptosis.
基金the National Natural Science Foundation of China(grant no.81872219)Science and Technology Project of Hunan Provincial Health Commission(grant no.B2015-040)+2 种基金Major Scientific and Technological Projects in Hunan Province(grant no.2019SK1010)2020 Li Ka Shing Foundation Cross-Disciplinary Research Grant(grant nos.2020LKSFG18B,2020LKSFG02E)Guangdong University Innovation Team Project(grant no.2021KCXTD047).
文摘Background:The role of autophagy in the formation of hypertrophic scars(HS)remains unclear.This study aimed to explore the role and potential mechanism of autophagy during the development of HS.Methods:RNA and protein expression levels of Beclin-1,p62,and LC3II in normal skin tissues and HS specimens from different patients were examined.Autophagy inducers and inhibitors were used to cure established HS in rabbit ears,and the expression of Beclin-1,p62,and LC3II at the RNA and protein level was determined.Lastly,the effects of autophagy inducers and inhibitors on HS development were analyzed.Results:Compared to normal skin tissues,the expression of LC3II and Beclin-1 was higher(P<0.05),while that of p62 was lower(P<0.05)in HS tissues.In addition,the LC3II/LC3I ratio was increased during HS formation,and the altered expression of the three proteins stabilized after one year.Administration of autophagy inducers enhanced the formation of HS as well as the expression levels of LC3II and Beclin-1 but decreased p62 expression.Meanwhile,administration of autophagy inhibitors increased the expression of LC3II,Beclin-1,and p62,along with reduced HS formation.Conclusion:Autophagic activity increased during HS initiation and subsequent stabilization.In addition,autophagy inhibitors were able to inhibit HS formation by suppressing autophagy,whereas autophagy inducers promoted scar hyperplasia by enhancing autophagy。
基金supported by Special Funds for the Introduction and Development of Talents of Shanxi Province, China
文摘Secondary damage is a critical determinant of the functional outcome in patients with spinal cord injury （SCI）, and involves multiple mechanisms of which the most important is the loss of nerve cells mediated by multiple factors. Autophagy can result in cell death, and plays a key role in the development of SCI. It has been recognized that valproic acid （VPA） is neuroprotective in certain experimental animal models, however, the levels of autophagic changes in the process of neuroprotection by VPA treatment following SCI are still unknown. In the present study, we determined the extent of autophagy after VPA treatment in a rat model of SCI. We found that both the mRNA and protein levels of Beclin-1 and LC3 were significantly increased at 1, 2, and 6 h after SCI and peaked at 2 h; however, Western blot showed that autophagy was markedly decreased by VPA treatment at 2 h post-injury. Besides, post-SCI treatment with VPA improved the Basso-Beattie-Bresnahan scale, increased the number of ventral horn motoneurons, and reduced myelin sheath damage compared with vehicle-treated animals at 42 days after SCI. Together, our results demonstrated the characteristics of autophagy expression following SCI, and foundthat VPA reduced autophagy and enhanced motor function.
文摘In a normal prostate,the process of controling cell death is essential to maintain tissue homeostasis and its inhibition may lead to the development of cancer.Androgen receptor signaling plays pivotal roles in the prostate development and homeostasis as well as in the progression of prostate cancer.The main treatment for prostate cancer is a combination of androgen deprivation therapy(ADT)using anti-androgens and docetaxil administration.However,ADT eventually fails due to a pathological unbalance of cell death processes,in particular apoptosis and autophagy.As a result prostate tumors may re-grow and progress into the castration resistant stage.The role of autophagy in tumorigenesis is complex and it could be a double-edged sword process,as autophagy defects promote cancer progression in association with various dangerous cellular processes,while functional autophagy enables cancer cell survival under stress and likely contributes to the resistance of treatment.Autophagy is often impaired in prostate cancer,due to either activation of the Akt/mTOR pathway,which normally inhibits autophagy,or through allelic loss of Beclin-1(BECN1),an essential autophagy gene.In particular,elucidating the interplay between autophagy and tumor cell metabolism will provide unique opportunities to identify new therapeutic targets and to develop synthetically lethal treatment strategies that preferentially target cancer cells,while sparing normal tissues.
