Chaperone-mediated autophagy is one of three types of autophagy and is characterized by the selective degradation of proteins.Chaperone-mediated autophagy contributes to energy balance and helps maintain cellular home...Chaperone-mediated autophagy is one of three types of autophagy and is characterized by the selective degradation of proteins.Chaperone-mediated autophagy contributes to energy balance and helps maintain cellular homeostasis,while providing nutrients and support for cell survival.Chaperone-mediated autophagy activity can be detected in almost all cells,including neurons.Owing to the extreme sensitivity of neurons to their environmental changes,maintaining neuronal homeostasis is critical for neuronal growth and survival.Chaperone-mediated autophagy dysfunction is closely related to central nervous system diseases.It has been shown that neuronal damage and cell death are accompanied by chaperone-mediated autophagy dysfunction.Under certain conditions,regulation of chaperone-mediated autophagy activity attenuates neurotoxicity.In this paper,we review the changes in chaperone-mediated autophagy in neurodegenerative diseases,brain injury,glioma,and autoimmune diseases.We also summarize the most recent research progress on chaperone-mediated autophagy regulation and discuss the potential of chaperone-mediated autophagy as a therapeutic target for central nervous system diseases.展开更多
Estrogen receptor alpha(ERα/ESR1)is overexpressed in over half of all breast cancers and is considered a valuable therapeutic target in ERαpositive breast cancer.Here,we designed a membrane-permeant Chaperonemediate...Estrogen receptor alpha(ERα/ESR1)is overexpressed in over half of all breast cancers and is considered a valuable therapeutic target in ERαpositive breast cancer.Here,we designed a membrane-permeant Chaperonemediated Autophagy Targeting Chimeras(CMATAC)peptide to knockdown endogenous ERαprotein through chaperone-mediated autophagy.The peptide contains a cell membrane-penetrating peptide(TAT)that allows the peptide to by-pass the plasma membrane,anαI peptide as a protein-binding peptide(PBD)that binds specifically to ERα,and CMA-targeting peptide(CTM)that targeting chaperone-mediated autophagy.We validated that ERαtargeting peptide was able to target and degrade ERαto reduce the viability of ERαpositive breast cancer cells.Taken together,our studies provided a new method to reduce the level of intracellular ERαprotein via CMATAC,and thus may provide a new strategy for the treatment of ERαpositive breast cancer.展开更多
BACKGROUND Liver fibrosis is a compensatory response during the tissue repair process in chronic liver injury,and finally leads to liver cirrhosis or even hepatocellular carcinoma.The pathogenesis of hepatic fibrosis ...BACKGROUND Liver fibrosis is a compensatory response during the tissue repair process in chronic liver injury,and finally leads to liver cirrhosis or even hepatocellular carcinoma.The pathogenesis of hepatic fibrosis is associated with the progressive accumulation of activated hepatic stellate cells(HSCs),which can transdiffer-entiate into myofibroblasts to produce an excess of the extracellular matrix(ECM).Myofibroblasts are the main source of the excessive ECM responsible for hepatic fibrosis.Therefore,activated hepatic stellate cells(aHSCs),the principal ECM producing cells in the injured liver,are a promising therapeutic target for the treatment of hepatic fibrosis.AIM To explore the effect of taurine on aHSC proliferation and the mechanisms involved.METHODS Human HSCs(LX-2)were randomly divided into five groups:Normal control group,platelet-derived growth factor-BB(PDGF-BB)(20 ng/mL)treated group,mmol/L,respectively)with PDGF-BB(20 ng/mL)treated group.Cell Counting Kit-8 method was performed to evaluate the effect of taurine on the viability of aHSCs.Enzyme-linked immunosorbent assay was used to estimate the effect of taurine on the levels of reactive oxygen species(ROS),malondialdehyde,glutathione,and iron concen-tration.Transmission electron microscopy was applied to observe the effect of taurine on the autophagosomes and ferroptosis features in aHSCs.Quantitative real-time polymerase chain reaction and Western blot analysis were performed to detect the effect of taurine on the expression ofα-SMA,Collagen I,Fibronectin 1,LC3B,ATG5,Beclin 1,PTGS2,SLC7A11,and p62.RESULTS Taurine promoted the death of aHSCs and reduced the deposition of the ECM.Treatment with taurine could alleviate autophagy in HSCs to inhibit their activation,by decreasing autophagosome formation,downregulating LC3B and Beclin 1 protein expression,and upregulating p62 protein expression.Meanwhile,treatment with taurine triggered ferroptosis and ferritinophagy to eliminate aHSCs characterized by iron overload,lipid ROS accumu-lation,glutathione depletion,and lipid peroxidation.Furthermore,bioinformatics analysis demonstrated that taurine had a direct targeting effect on nuclear receptor coactivator 4,exhibiting the best average binding affinity of-20.99 kcal/mol.CONCLUSION Taurine exerts therapeutic effects on liver fibrosis via mechanisms that involve inhibition of autophagy and trigger of ferroptosis and ferritinophagy in HSCs to eliminate aHSCs.展开更多
Objective:To investigate the role and the molecular mechanisms of apoptotic signaling in ferroptosis to regulate tumor radiosensitivity.Methods:Reactive oxygen species(ROS)and lipid peroxide levels were detected in Mo...Objective:To investigate the role and the molecular mechanisms of apoptotic signaling in ferroptosis to regulate tumor radiosensitivity.Methods:Reactive oxygen species(ROS)and lipid peroxide levels were detected in Mouse embryonic fibroblasts(MEFs)with Bcl-xL or Mcl-1 deficiency induced by erastin.Colony formation,ROS,lipid peroxidation and the transcription/translation levels of PTGS2 were measured in Bcl-xL knockdown tumor cells induced by 5 Gyγ-rays or co-treated with ferrostatin-1(Ferr-1).The protein levels of LPCAT3,ACSL4 and PEBP1 in Bcl-xL knockout MEF cells were evaluated in Bcl-xL knockout MEF cells post-radiation.Moreover,the interaction of heat shock protein 90(HSP90)with Bcl-xL,GPX4,or LAMP2A was detected by protein mass spectrometry and immunoprecipitation assays.Results:Manipulating Bcl-xL levels facilitated radiation-induced ferroptosis by augmenting the enzymatic oxidation of polyunsaturated fatty acids(PUFAs)and enhancing chaperone-mediated autophagy(CMA)of glutathione peroxidase 4(GPX4)(MEF cell line:t=4.540,P<0.01;A549 cell line:t=56.16,P<0.0001;t=4.885,P<0.01;HCT116 cell line:t=14.75,P<0.01;t=7.363,P<0.05).Downregulating Bcl-xL expression promoted the activity of acyl-CoA synthetase long-chain family member 4(ACSL4),thus increasing the enzymatic oxidation of PUFAs(t=4.258,P<0.01).Moreover,depletion of Bcl-xL expedited the CMA process targeting GPX4 by facilitating the association of GPX4 with heat shock protein 90(HSP90)and LAMP2A following radiation exposure.Subsequent degradation of GPX4 led to the accumulation of lipid peroxides,ultimately triggering ferroptosis.Conclusions:Our study provides initial insights into the regulatory role of Bcl-xL in ferroptosis and underscores the potential of targeting Bcl-xL as a promising therapeutic strategy for cancer by modulating both apoptotic and ferroptotic pathways.展开更多
Stem cells are a group of cells with unique self-renewal and differentiation abilities that have great prospects in the repair of spinal cord injury. However, stem cell renewal and differentiation require strict contr...Stem cells are a group of cells with unique self-renewal and differentiation abilities that have great prospects in the repair of spinal cord injury. However, stem cell renewal and differentiation require strict control of protein turnover in the stem cells to achieve cell remodeling. As a highly conserved “gatekeeper” of cell homeostasis, autophagy can regulate cell remodeling by precisely controlling protein turnover in cells. Recently, it has been found that the expression of autophagy markers changes in animal models of spinal cord injury. Therefore, understanding whether autophagy can affect the fate of stem cells and promote the repair of spinal cord injury is of considerable clinical value. This review expounds the importance of autophagy homeostasis control for the repair of spinal cord injury from three aspects—pathophysiology of spinal cord injury, autophagy and stem cell function, and autophagy and stem cell function in spinal cord injury—and proposes the synergistic therapeutic effect of autophagy and stem cells in spinal cord injury.展开更多
Autophagy, a cellular process of "self-eating" by which intracellular components are degraded within the lysosome, is an evolutionarily conserved response to various stresses. Autophagy is associated with nu...Autophagy, a cellular process of "self-eating" by which intracellular components are degraded within the lysosome, is an evolutionarily conserved response to various stresses. Autophagy is associated with numerous patho-physiological conditions, and dysregulation of autophagy contributes to the pathogenesis of a variety of human diseases including cancer. Depending on context, activation of autophagy may promote either cell survival or death, two major events that determine pathological process of many illnesses. Importantly, the activity of autophagy is often associated with apoptosis, another critical cellular process determining cellular fate. A better understanding of biology of autophagy and its implication in human health and disorder, as well as the relationship between autophagy and apoptosis, has the potential of facilitating the development of autophagy -based therapeutic interventions for human diseases such as cancer.展开更多
Cholesterol and cholesterol oxides impact on the functional properties of cells, in respect of the intracellular and extracellular distribution of compounds across cell membranes, carcinogenesis and drug resistance. A...Cholesterol and cholesterol oxides impact on the functional properties of cells, in respect of the intracellular and extracellular distribution of compounds across cell membranes, carcinogenesis and drug resistance. Abnormal levels of cholesterol oxides and steroids in cancerous tissues promote interest in steroid receptor cross-talk during cell-signalling and the steroid metabolome of cancer patients. The research literature links the cytotoxic properties of oxysterols to interference with the NO/cGMP pathway. cGMP participates in cell-signalling and has a molecular structure that relates to cancer-inducing and cancer-preventing agents. This study uses a molecular modelling approach to compare the structures of cholesterol oxides to cGMP. Cholesterol and cholesterol oxide structures fit to a cGMP structural template in several ways, some of which are replicated by corticosteroids and gonadal steroid hormones. The results of this study support the concept that cholesterol oxides modulate cell apoptosis and autophagy via the NO/cGMP pathway and in conjunction with steroid hormones participate in modulating regulation of cell function by cGMP.展开更多
Objective: To investigate the molecular mechanisms of Yuye Decotion in the treatment of diabetic kidney disease using network pharmacology methods and molecular docking techniques. Methods: Obtain the transcriptome ge...Objective: To investigate the molecular mechanisms of Yuye Decotion in the treatment of diabetic kidney disease using network pharmacology methods and molecular docking techniques. Methods: Obtain the transcriptome gene expression of diabetic nephropathy through GEO database, and extract genes related to autophagy. Screen the active ingredients and corresponding targets of Yuye Decoction through the TCMSP database, and map the drug prediction targets and disease targets to obtain the autophagy-related Yuye treatment targets for diabetic nephropathy point. Use String database combined with Cytoscape 3.7.2 software to construct the "drug-active ingredient-target" network and protein interaction network of Yuyetang for the treatment of diabetic nephropathy. The target point of liquid soup in the treatment of diabetic nephropathy was analyzed by GO biological process enrichment analysis and KEGG pathway enrichment analysis, and finally used Pymol and other software to analyze the core active components of Yuye Decotion and The core target protein undergoes molecular docking verification. Results: (i)100 eligible diabetic nephropathy and autophagy related genes were screened, and the potential targets of Yuye Decoction were 1,428. The acquired genes related to diabetic nephropathy and autophagy were mapped to potential targets of Yuye Decoction, and 22 therapeutic targets were obtained. GO biological process enrichment analysis and KEGG pathway enrichment analysis found that the pathways related to autophagy in the treatment of diabetic nephropathy by Yuye Decoction may include mTOR signaling pathway, phospholipase D signaling pathway, insulin resistance, EGFR tyrosine kinase inhibitor resistance, Apoptosis, PI3K /Akt signaling pathway, NF-κB signaling pathway, etc. (ii)The protein interaction network shows that VEGFA, ERBB2, GASP3, MAPK8, MYC, CDKN1A, EGFR, BCL2L1 may be the key targets of Yuye Decoction in the treatment of diabetic nephropathy. Molecular docking realizes the binding of 4 core active ingredients to 8 core target proteins. Conclusions: The research results show that Yuye Decoction treats diabetic nephropathy through multi-component, multi-target, and multi-pathway action, and provides new theoretical basis for the study of pharmacological effects and clinical application of Yuye Decoction in the treatment of diabetic nephropathy in autophagy-related aspects.展开更多
Chaperone-mediated autophagy(CMA)is a lysosome-dependent selective degradation pathway implicated in the pathogenesis of cancer and neurodegenerative diseases.However,the mechanisms that regulate CMA are not fully und...Chaperone-mediated autophagy(CMA)is a lysosome-dependent selective degradation pathway implicated in the pathogenesis of cancer and neurodegenerative diseases.However,the mechanisms that regulate CMA are not fully understood.Here,using unbiased drug screening approaches,we discover Metformin,a drug that is commonly the first medication prescribed for type 2 diabetes,can induce CMA.We delineate the mechanism of CMA induction by Metformin to be via activation of TAK1-IKKα/β signaling that leads to phosphorylation of Ser85 of the key mediator of CMA,Hsc70,and its activation.Notably,we find that amyloid-beta precursor protein(APP)is a CMA substrate and that it binds to Hsc70 in an IKKα/β-dependent manner.The inhibition of CMA-mediated degradation of APP enhances its cytotoxicity.Importantly,we find that in the APP/PS1 mouse model of Alzheimer's disease(AD),activation of CMA by Hsc70 overexpression or Metformin potently reduces the accumulated brain Aβplaque levels and reverses the molecular and behavioral AD phenotypes.Our study elucidates a novel mechanism of CMA regulation via Metformin-TAK1-IKKα/β-Hsc70 signaling and suggests Metformin as a new activator of CMA for diseases,such as AD,where such therapeutic intervention could be beneficial.展开更多
Background:Progressive accumulation ofα-synuclein is a key step in the pathological development of Parkinson’s disease.Impaired protein degradation and increased levels ofα-synuclein may trigger a pathological aggr...Background:Progressive accumulation ofα-synuclein is a key step in the pathological development of Parkinson’s disease.Impaired protein degradation and increased levels ofα-synuclein may trigger a pathological aggregation in vitro and in vivo.The chaperone-mediated autophagy(CMA)pathway is involved in the intracellular degradation processes ofα-synuclein.Dysfunction of the CMA pathway impairsα-synuclein degradation and causes cytotoxicity.Results:In the present study,we investigated the effects on the CMA pathway andα-synuclein aggregation using bioactive ingredients(Dihydromyricetin(DHM)and Salvianolic acid B(Sal B))extracted from natural medicinal plants.In both cell-free and cellular models ofα-synuclein aggregation,after administration of DHM and Sal B,we observed significant inhibition ofα-synuclein accumulation and aggregation.Cells were co-transfected with a Cterminal modifiedα-synuclein(SynT)and synphilin-1,and then treated with DHM(10μM)and Sal B(50μM)16 hours after transfection;levels ofα-synuclein aggregation decreased significantly(68%for DHM and 75%for Sal B).Concomitantly,we detected increased levels of LAMP-1(a marker of lysosomal homeostasis)and LAMP-2A(a key marker of CMA).Immunofluorescence analyses showed increased colocalization between LAMP-1 and LAMP-2A withα-synuclein inclusions after treatment with DHM and Sal B.We also found increased levels of LAMP-1 and LAMP-2A both in vitro and in vivo,along with decreased levels ofα-synuclein.Moreover,DHM and Sal B treatments exhibited anti-inflammatory activities,preventing astroglia-and microglia-mediated neuroinflammation in BAC-α-syn-GFP transgenic mice.Conclusions:Our data indicate that DHM and Sal B are effective in modulatingα-synuclein accumulation and aggregate formation and augmenting activation of CMA,holding potential for the treatment of Parkinson’s disease.展开更多
Chaperone-mediated autophagy （CMA）, one of the main pathways of lysosomal proteolysis, is characterized by the selective targeting and direct translocation into the lysosomal lumen of substrate proteins containing a...Chaperone-mediated autophagy （CMA）, one of the main pathways of lysosomal proteolysis, is characterized by the selective targeting and direct translocation into the lysosomal lumen of substrate proteins containing a targeting motif biochemically related to the pentapeptide KFERQ. Along with the other two lysosomal pathways, macro- and micro-autophagy, CMA is essential for maintaining cellular homeostasis and survival by selectively degrading misfolded, oxidized, or damaged cytosolic proteins. CMA plays an important role in pathologies such as cancer, kidney disorders, and neurodegenerative diseases. Neurons are post-mitotic and highly susceptible to dysfunction of cellular quality-control systems. Maintaining a balance between protein synthesis and degradation is critical for neuronal functions and homeostasis. Recent studies have revealed several new mechanisms by which CMA protects neurons through regulating factors critical for their viability and homeostasis. In the current review, we summarize recent advances in the understanding of the regulation and physiology of CMA with a specific focus on its possible roles in neuroprotection.展开更多
Lysosomes degrade dysfunctional intracellular components via three pathways： macroautophagy, microautophagy, and chaperone-mediated autophagy （CMA）. Unlike the other two, CMA degrades cytosolic proteins with a reco...Lysosomes degrade dysfunctional intracellular components via three pathways： macroautophagy, microautophagy, and chaperone-mediated autophagy （CMA）. Unlike the other two, CMA degrades cytosolic proteins with a recognized KFERQ-like motif in lysosomes and is important for cellular homeostasis. CMA activity declines with age and is altered in neurodegenerative diseases. Its impairment leads to the accumulation of aggregated proteins, some of which may be directly tied to the pathogenic processes of neurodegenerative diseases. Its induction may accelerate the clearance of pathogenic proteins and promote cell survival, representing a potential therapeutic approach for the treatment of neurodegenerative diseases. In this review, we summarize the current findings on how CMA is involved in neurodegenerative diseases, especially in Parkinson＇s disease.展开更多
Macroautophagy has been implicated in modulating the therapeutic function of mesenchymal stromal cells(MSCs).However,the biological function of chaperone-mediated autophagy(CMA)in MSCs remains elusive.Here,we found th...Macroautophagy has been implicated in modulating the therapeutic function of mesenchymal stromal cells(MSCs).However,the biological function of chaperone-mediated autophagy(CMA)in MSCs remains elusive.Here,we found that CMA was inhibited in MSCs in response to the proinflammatory cytokines interferon-γ(IFN-γ)and tumor necrosis factor-α(TNF-α).In addition,suppression of CMA by knocking down the CMA-related lysosomal receptor lysosomal-associated membrane protein 2(LAMP-2A)in MSCs significantly enhanced the immunosuppressive effect of MSCs on T cell proliferation,and as expected,LAMP-2A overexpression in MSCs exerted the opposite effect on T cell proliferation.This effect of CMA on the immunosuppressive function of MSCs was attributed to its negative regulation of the expression of chemokine C-X-C motif ligand 10(CXCL10),which recruits inflammatory cells,especially T cells,to MSCs,and inducible nitric oxide synthase(iNOS),which leads to the subsequent inhibition of T cell proliferation via nitric oxide(NO).Mechanistically,CMA inhibition dramatically promoted IFN-γplus TNF-α-induced activation of NF-κB and STAT1,leading to the enhanced expression of CXCL10 and iNOS in MSCs.Furthermore,we found that IFN-γplus TNF-α-induced AKT activation contributed to CMA inhibition in MSCs.More interestingly,CMA-deficient MSCs exhibited improved therapeutic efficacy in inflammatory liver injury.Taken together,our findings established CMA inhibition as a critical contributor to the immunosuppressive function of MSCs induced by inflammatory cytokines nd highlighted a previously unknown function of CMA.展开更多
Chaperone-mediated autophagy(CMA)selectively delivers cytosolic proteins with an exposed CMA-targeting motif to lysosomes for degradation and plays an important role in protein quality control and cellular homeostasis...Chaperone-mediated autophagy(CMA)selectively delivers cytosolic proteins with an exposed CMA-targeting motif to lysosomes for degradation and plays an important role in protein quality control and cellular homeostasis.A growing body of evidence supports the hypothesis that CMA dysfunction may be involved in the pathogenic process of neurodegenerative diseases.Both down-regulation and compensatory up-regulation in CMA activities have been observed in association with neurodegenerative conditions.Recent studies have revealed several new mechanisms by which CMA function may be involved in the regulation of factors critical for neuronal viability and homeostasis.Here,we summarize these recent advances in the understanding of the relationship between CMA dysfunction and neurodegeneration and discuss the therapeutic potential of targeting CMA in the treatment of neurodegenerative diseases.展开更多
基金supported by the National Nature Science Foundation of China,Nos.81871603(to XZ)and 82171322(to ZF)Discipline Boost Program of the First Affiliated Hospital of Air Force Military Medical University,No.XJZT21J08(to XZ)the Natural Science Foundation of Shaanxi Province of China,No.2022KJXX-102(to ZF)。
文摘Chaperone-mediated autophagy is one of three types of autophagy and is characterized by the selective degradation of proteins.Chaperone-mediated autophagy contributes to energy balance and helps maintain cellular homeostasis,while providing nutrients and support for cell survival.Chaperone-mediated autophagy activity can be detected in almost all cells,including neurons.Owing to the extreme sensitivity of neurons to their environmental changes,maintaining neuronal homeostasis is critical for neuronal growth and survival.Chaperone-mediated autophagy dysfunction is closely related to central nervous system diseases.It has been shown that neuronal damage and cell death are accompanied by chaperone-mediated autophagy dysfunction.Under certain conditions,regulation of chaperone-mediated autophagy activity attenuates neurotoxicity.In this paper,we review the changes in chaperone-mediated autophagy in neurodegenerative diseases,brain injury,glioma,and autoimmune diseases.We also summarize the most recent research progress on chaperone-mediated autophagy regulation and discuss the potential of chaperone-mediated autophagy as a therapeutic target for central nervous system diseases.
基金the National Natural Science Foundation of China(Grant Nos:81272260&81572712 to L.Chen)Natural Science Fund for Distinguished Young Scholars of Jiangsu Province(SBK2020010058)the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Estrogen receptor alpha(ERα/ESR1)is overexpressed in over half of all breast cancers and is considered a valuable therapeutic target in ERαpositive breast cancer.Here,we designed a membrane-permeant Chaperonemediated Autophagy Targeting Chimeras(CMATAC)peptide to knockdown endogenous ERαprotein through chaperone-mediated autophagy.The peptide contains a cell membrane-penetrating peptide(TAT)that allows the peptide to by-pass the plasma membrane,anαI peptide as a protein-binding peptide(PBD)that binds specifically to ERα,and CMA-targeting peptide(CTM)that targeting chaperone-mediated autophagy.We validated that ERαtargeting peptide was able to target and degrade ERαto reduce the viability of ERαpositive breast cancer cells.Taken together,our studies provided a new method to reduce the level of intracellular ERαprotein via CMATAC,and thus may provide a new strategy for the treatment of ERαpositive breast cancer.
基金Supported by Guangxi Natural Science Foundation Program,No.2020GXNSFAA297160 and No.2018GXNSFBA050050Guipai Xinglin Youth Talent Project of Guangxi University of Chinese Medicine,No.2022C042.
文摘BACKGROUND Liver fibrosis is a compensatory response during the tissue repair process in chronic liver injury,and finally leads to liver cirrhosis or even hepatocellular carcinoma.The pathogenesis of hepatic fibrosis is associated with the progressive accumulation of activated hepatic stellate cells(HSCs),which can transdiffer-entiate into myofibroblasts to produce an excess of the extracellular matrix(ECM).Myofibroblasts are the main source of the excessive ECM responsible for hepatic fibrosis.Therefore,activated hepatic stellate cells(aHSCs),the principal ECM producing cells in the injured liver,are a promising therapeutic target for the treatment of hepatic fibrosis.AIM To explore the effect of taurine on aHSC proliferation and the mechanisms involved.METHODS Human HSCs(LX-2)were randomly divided into five groups:Normal control group,platelet-derived growth factor-BB(PDGF-BB)(20 ng/mL)treated group,mmol/L,respectively)with PDGF-BB(20 ng/mL)treated group.Cell Counting Kit-8 method was performed to evaluate the effect of taurine on the viability of aHSCs.Enzyme-linked immunosorbent assay was used to estimate the effect of taurine on the levels of reactive oxygen species(ROS),malondialdehyde,glutathione,and iron concen-tration.Transmission electron microscopy was applied to observe the effect of taurine on the autophagosomes and ferroptosis features in aHSCs.Quantitative real-time polymerase chain reaction and Western blot analysis were performed to detect the effect of taurine on the expression ofα-SMA,Collagen I,Fibronectin 1,LC3B,ATG5,Beclin 1,PTGS2,SLC7A11,and p62.RESULTS Taurine promoted the death of aHSCs and reduced the deposition of the ECM.Treatment with taurine could alleviate autophagy in HSCs to inhibit their activation,by decreasing autophagosome formation,downregulating LC3B and Beclin 1 protein expression,and upregulating p62 protein expression.Meanwhile,treatment with taurine triggered ferroptosis and ferritinophagy to eliminate aHSCs characterized by iron overload,lipid ROS accumu-lation,glutathione depletion,and lipid peroxidation.Furthermore,bioinformatics analysis demonstrated that taurine had a direct targeting effect on nuclear receptor coactivator 4,exhibiting the best average binding affinity of-20.99 kcal/mol.CONCLUSION Taurine exerts therapeutic effects on liver fibrosis via mechanisms that involve inhibition of autophagy and trigger of ferroptosis and ferritinophagy in HSCs to eliminate aHSCs.
基金the National Science Fund for Excellent Young Scholars(grant number 12122510)the National Natural Science Foundation of China(grant number 32171240)+1 种基金Anhui Provincial Natural Science Foundation(grant numbers 2108085MH279)the HFIPS Director’s Fund(grant numbers BJPY2021B07 and BJPY2023A010).
文摘Objective:To investigate the role and the molecular mechanisms of apoptotic signaling in ferroptosis to regulate tumor radiosensitivity.Methods:Reactive oxygen species(ROS)and lipid peroxide levels were detected in Mouse embryonic fibroblasts(MEFs)with Bcl-xL or Mcl-1 deficiency induced by erastin.Colony formation,ROS,lipid peroxidation and the transcription/translation levels of PTGS2 were measured in Bcl-xL knockdown tumor cells induced by 5 Gyγ-rays or co-treated with ferrostatin-1(Ferr-1).The protein levels of LPCAT3,ACSL4 and PEBP1 in Bcl-xL knockout MEF cells were evaluated in Bcl-xL knockout MEF cells post-radiation.Moreover,the interaction of heat shock protein 90(HSP90)with Bcl-xL,GPX4,or LAMP2A was detected by protein mass spectrometry and immunoprecipitation assays.Results:Manipulating Bcl-xL levels facilitated radiation-induced ferroptosis by augmenting the enzymatic oxidation of polyunsaturated fatty acids(PUFAs)and enhancing chaperone-mediated autophagy(CMA)of glutathione peroxidase 4(GPX4)(MEF cell line:t=4.540,P<0.01;A549 cell line:t=56.16,P<0.0001;t=4.885,P<0.01;HCT116 cell line:t=14.75,P<0.01;t=7.363,P<0.05).Downregulating Bcl-xL expression promoted the activity of acyl-CoA synthetase long-chain family member 4(ACSL4),thus increasing the enzymatic oxidation of PUFAs(t=4.258,P<0.01).Moreover,depletion of Bcl-xL expedited the CMA process targeting GPX4 by facilitating the association of GPX4 with heat shock protein 90(HSP90)and LAMP2A following radiation exposure.Subsequent degradation of GPX4 led to the accumulation of lipid peroxides,ultimately triggering ferroptosis.Conclusions:Our study provides initial insights into the regulatory role of Bcl-xL in ferroptosis and underscores the potential of targeting Bcl-xL as a promising therapeutic strategy for cancer by modulating both apoptotic and ferroptotic pathways.
基金supported by the National Natural Science Foundation of China,Nos. 32170825 and 31971108 (both to GW)。
文摘Stem cells are a group of cells with unique self-renewal and differentiation abilities that have great prospects in the repair of spinal cord injury. However, stem cell renewal and differentiation require strict control of protein turnover in the stem cells to achieve cell remodeling. As a highly conserved “gatekeeper” of cell homeostasis, autophagy can regulate cell remodeling by precisely controlling protein turnover in cells. Recently, it has been found that the expression of autophagy markers changes in animal models of spinal cord injury. Therefore, understanding whether autophagy can affect the fate of stem cells and promote the repair of spinal cord injury is of considerable clinical value. This review expounds the importance of autophagy homeostasis control for the repair of spinal cord injury from three aspects—pathophysiology of spinal cord injury, autophagy and stem cell function, and autophagy and stem cell function in spinal cord injury—and proposes the synergistic therapeutic effect of autophagy and stem cells in spinal cord injury.
文摘Autophagy, a cellular process of "self-eating" by which intracellular components are degraded within the lysosome, is an evolutionarily conserved response to various stresses. Autophagy is associated with numerous patho-physiological conditions, and dysregulation of autophagy contributes to the pathogenesis of a variety of human diseases including cancer. Depending on context, activation of autophagy may promote either cell survival or death, two major events that determine pathological process of many illnesses. Importantly, the activity of autophagy is often associated with apoptosis, another critical cellular process determining cellular fate. A better understanding of biology of autophagy and its implication in human health and disorder, as well as the relationship between autophagy and apoptosis, has the potential of facilitating the development of autophagy -based therapeutic interventions for human diseases such as cancer.
文摘Cholesterol and cholesterol oxides impact on the functional properties of cells, in respect of the intracellular and extracellular distribution of compounds across cell membranes, carcinogenesis and drug resistance. Abnormal levels of cholesterol oxides and steroids in cancerous tissues promote interest in steroid receptor cross-talk during cell-signalling and the steroid metabolome of cancer patients. The research literature links the cytotoxic properties of oxysterols to interference with the NO/cGMP pathway. cGMP participates in cell-signalling and has a molecular structure that relates to cancer-inducing and cancer-preventing agents. This study uses a molecular modelling approach to compare the structures of cholesterol oxides to cGMP. Cholesterol and cholesterol oxide structures fit to a cGMP structural template in several ways, some of which are replicated by corticosteroids and gonadal steroid hormones. The results of this study support the concept that cholesterol oxides modulate cell apoptosis and autophagy via the NO/cGMP pathway and in conjunction with steroid hormones participate in modulating regulation of cell function by cGMP.
基金National Natural Science Foundation of China,Regional Fund(No.81860836)。
文摘Objective: To investigate the molecular mechanisms of Yuye Decotion in the treatment of diabetic kidney disease using network pharmacology methods and molecular docking techniques. Methods: Obtain the transcriptome gene expression of diabetic nephropathy through GEO database, and extract genes related to autophagy. Screen the active ingredients and corresponding targets of Yuye Decoction through the TCMSP database, and map the drug prediction targets and disease targets to obtain the autophagy-related Yuye treatment targets for diabetic nephropathy point. Use String database combined with Cytoscape 3.7.2 software to construct the "drug-active ingredient-target" network and protein interaction network of Yuyetang for the treatment of diabetic nephropathy. The target point of liquid soup in the treatment of diabetic nephropathy was analyzed by GO biological process enrichment analysis and KEGG pathway enrichment analysis, and finally used Pymol and other software to analyze the core active components of Yuye Decotion and The core target protein undergoes molecular docking verification. Results: (i)100 eligible diabetic nephropathy and autophagy related genes were screened, and the potential targets of Yuye Decoction were 1,428. The acquired genes related to diabetic nephropathy and autophagy were mapped to potential targets of Yuye Decoction, and 22 therapeutic targets were obtained. GO biological process enrichment analysis and KEGG pathway enrichment analysis found that the pathways related to autophagy in the treatment of diabetic nephropathy by Yuye Decoction may include mTOR signaling pathway, phospholipase D signaling pathway, insulin resistance, EGFR tyrosine kinase inhibitor resistance, Apoptosis, PI3K /Akt signaling pathway, NF-κB signaling pathway, etc. (ii)The protein interaction network shows that VEGFA, ERBB2, GASP3, MAPK8, MYC, CDKN1A, EGFR, BCL2L1 may be the key targets of Yuye Decoction in the treatment of diabetic nephropathy. Molecular docking realizes the binding of 4 core active ingredients to 8 core target proteins. Conclusions: The research results show that Yuye Decoction treats diabetic nephropathy through multi-component, multi-target, and multi-pathway action, and provides new theoretical basis for the study of pharmacological effects and clinical application of Yuye Decoction in the treatment of diabetic nephropathy in autophagy-related aspects.
基金Financial support was received from the National Key R&D Program of China(2017YFA0104200)the National Natural Science Foundation of China(No.91854108,81773182 and 31601121).
文摘Chaperone-mediated autophagy(CMA)is a lysosome-dependent selective degradation pathway implicated in the pathogenesis of cancer and neurodegenerative diseases.However,the mechanisms that regulate CMA are not fully understood.Here,using unbiased drug screening approaches,we discover Metformin,a drug that is commonly the first medication prescribed for type 2 diabetes,can induce CMA.We delineate the mechanism of CMA induction by Metformin to be via activation of TAK1-IKKα/β signaling that leads to phosphorylation of Ser85 of the key mediator of CMA,Hsc70,and its activation.Notably,we find that amyloid-beta precursor protein(APP)is a CMA substrate and that it binds to Hsc70 in an IKKα/β-dependent manner.The inhibition of CMA-mediated degradation of APP enhances its cytotoxicity.Importantly,we find that in the APP/PS1 mouse model of Alzheimer's disease(AD),activation of CMA by Hsc70 overexpression or Metformin potently reduces the accumulated brain Aβplaque levels and reverses the molecular and behavioral AD phenotypes.Our study elucidates a novel mechanism of CMA regulation via Metformin-TAK1-IKKα/β-Hsc70 signaling and suggests Metformin as a new activator of CMA for diseases,such as AD,where such therapeutic intervention could be beneficial.
基金We would like to acknowledge financial supports by the National Natural Science Foundation(81430025,81701265,31800898,U801681)Acknowledgements are also to the supports of the Swedish Research Council(K2015-61X-22297-03-4)+2 种基金EU-JPND(aSynProtec),EU-JPND(REfrAME),EU H2020-MSCA-ITN-2016(Syndegen),BAGADILICO-Excellence in Parkinson and Huntington Research,the Strong Research Environment MultiPark(Multidisciplinary research on Parkinson’s disease),the Swedish Parkinson Foundation(Parkinsonfonden),Torsten Söderbergs Foundation,Olle Engkvist Byggmästere FoundationW.L.is supported by a scholarship from the China Scholarship CouncilTFO is supported by the DFG Center for Nanoscaly Microscopy and Molecular Physiology of the Brain(CNMPB).
文摘Background:Progressive accumulation ofα-synuclein is a key step in the pathological development of Parkinson’s disease.Impaired protein degradation and increased levels ofα-synuclein may trigger a pathological aggregation in vitro and in vivo.The chaperone-mediated autophagy(CMA)pathway is involved in the intracellular degradation processes ofα-synuclein.Dysfunction of the CMA pathway impairsα-synuclein degradation and causes cytotoxicity.Results:In the present study,we investigated the effects on the CMA pathway andα-synuclein aggregation using bioactive ingredients(Dihydromyricetin(DHM)and Salvianolic acid B(Sal B))extracted from natural medicinal plants.In both cell-free and cellular models ofα-synuclein aggregation,after administration of DHM and Sal B,we observed significant inhibition ofα-synuclein accumulation and aggregation.Cells were co-transfected with a Cterminal modifiedα-synuclein(SynT)and synphilin-1,and then treated with DHM(10μM)and Sal B(50μM)16 hours after transfection;levels ofα-synuclein aggregation decreased significantly(68%for DHM and 75%for Sal B).Concomitantly,we detected increased levels of LAMP-1(a marker of lysosomal homeostasis)and LAMP-2A(a key marker of CMA).Immunofluorescence analyses showed increased colocalization between LAMP-1 and LAMP-2A withα-synuclein inclusions after treatment with DHM and Sal B.We also found increased levels of LAMP-1 and LAMP-2A both in vitro and in vivo,along with decreased levels ofα-synuclein.Moreover,DHM and Sal B treatments exhibited anti-inflammatory activities,preventing astroglia-and microglia-mediated neuroinflammation in BAC-α-syn-GFP transgenic mice.Conclusions:Our data indicate that DHM and Sal B are effective in modulatingα-synuclein accumulation and aggregate formation and augmenting activation of CMA,holding potential for the treatment of Parkinson’s disease.
基金partially supported by the FMMU Research FoundationNational Basic Research Development Program of China (2011CB510000)the National Natural Science Foundation of China (31371400)
文摘Chaperone-mediated autophagy （CMA）, one of the main pathways of lysosomal proteolysis, is characterized by the selective targeting and direct translocation into the lysosomal lumen of substrate proteins containing a targeting motif biochemically related to the pentapeptide KFERQ. Along with the other two lysosomal pathways, macro- and micro-autophagy, CMA is essential for maintaining cellular homeostasis and survival by selectively degrading misfolded, oxidized, or damaged cytosolic proteins. CMA plays an important role in pathologies such as cancer, kidney disorders, and neurodegenerative diseases. Neurons are post-mitotic and highly susceptible to dysfunction of cellular quality-control systems. Maintaining a balance between protein synthesis and degradation is critical for neuronal functions and homeostasis. Recent studies have revealed several new mechanisms by which CMA protects neurons through regulating factors critical for their viability and homeostasis. In the current review, we summarize recent advances in the understanding of the regulation and physiology of CMA with a specific focus on its possible roles in neuroprotection.
基金supported in part by grants of NIH,USA (AG023695,NS079858,and ES015317)
文摘Lysosomes degrade dysfunctional intracellular components via three pathways： macroautophagy, microautophagy, and chaperone-mediated autophagy （CMA）. Unlike the other two, CMA degrades cytosolic proteins with a recognized KFERQ-like motif in lysosomes and is important for cellular homeostasis. CMA activity declines with age and is altered in neurodegenerative diseases. Its impairment leads to the accumulation of aggregated proteins, some of which may be directly tied to the pathogenic processes of neurodegenerative diseases. Its induction may accelerate the clearance of pathogenic proteins and promote cell survival, representing a potential therapeutic approach for the treatment of neurodegenerative diseases. In this review, we summarize the current findings on how CMA is involved in neurodegenerative diseases, especially in Parkinson＇s disease.
基金supported by the Ministry of Science and Technology of China(2015CB943300 and 2011CB966200)the National Natural Science Foundation of China(81873447 and 81670540)+1 种基金The Program of Science and Technology Commission of Shanghai Municipality(19ZR1409200 and 19ZR1430900)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA01040000).
文摘Macroautophagy has been implicated in modulating the therapeutic function of mesenchymal stromal cells(MSCs).However,the biological function of chaperone-mediated autophagy(CMA)in MSCs remains elusive.Here,we found that CMA was inhibited in MSCs in response to the proinflammatory cytokines interferon-γ(IFN-γ)and tumor necrosis factor-α(TNF-α).In addition,suppression of CMA by knocking down the CMA-related lysosomal receptor lysosomal-associated membrane protein 2(LAMP-2A)in MSCs significantly enhanced the immunosuppressive effect of MSCs on T cell proliferation,and as expected,LAMP-2A overexpression in MSCs exerted the opposite effect on T cell proliferation.This effect of CMA on the immunosuppressive function of MSCs was attributed to its negative regulation of the expression of chemokine C-X-C motif ligand 10(CXCL10),which recruits inflammatory cells,especially T cells,to MSCs,and inducible nitric oxide synthase(iNOS),which leads to the subsequent inhibition of T cell proliferation via nitric oxide(NO).Mechanistically,CMA inhibition dramatically promoted IFN-γplus TNF-α-induced activation of NF-κB and STAT1,leading to the enhanced expression of CXCL10 and iNOS in MSCs.Furthermore,we found that IFN-γplus TNF-α-induced AKT activation contributed to CMA inhibition in MSCs.More interestingly,CMA-deficient MSCs exhibited improved therapeutic efficacy in inflammatory liver injury.Taken together,our findings established CMA inhibition as a critical contributor to the immunosuppressive function of MSCs induced by inflammatory cytokines nd highlighted a previously unknown function of CMA.
基金This work was in part supported by grants to Z.M(NIH AG023695,NSO79858,and ES015317).
文摘Chaperone-mediated autophagy(CMA)selectively delivers cytosolic proteins with an exposed CMA-targeting motif to lysosomes for degradation and plays an important role in protein quality control and cellular homeostasis.A growing body of evidence supports the hypothesis that CMA dysfunction may be involved in the pathogenic process of neurodegenerative diseases.Both down-regulation and compensatory up-regulation in CMA activities have been observed in association with neurodegenerative conditions.Recent studies have revealed several new mechanisms by which CMA function may be involved in the regulation of factors critical for neuronal viability and homeostasis.Here,we summarize these recent advances in the understanding of the relationship between CMA dysfunction and neurodegeneration and discuss the therapeutic potential of targeting CMA in the treatment of neurodegenerative diseases.
