BACKGROUND The low survival rate of mesenchymal stem cells(MSCs)caused by anoikis,a form of apoptosis,limits the therapeutic efficacy of MSCs.As a proapoptotic molecule,mammalian Ste20-like kinase 1(Mst1)can increase ...BACKGROUND The low survival rate of mesenchymal stem cells(MSCs)caused by anoikis,a form of apoptosis,limits the therapeutic efficacy of MSCs.As a proapoptotic molecule,mammalian Ste20-like kinase 1(Mst1)can increase the production of reactive oxygen species(ROS),thereby promoting anoikis.Recently,we found that Mst1 inhibition could protect mouse bone marrow MSCs(mBMSCs)from H 2 O 2-induced cell apoptosis by inducing autophagy and reducing ROS production.However,the influence of Mst1 inhibition on anoikis in mBMSCs remains unclear.AIM To investigate the mechanisms by which Mst1 inhibition acts on anoikis in isolated mBMSCs.METHODS Poly-2-hydroxyethyl methacrylate-induced anoikis was used following the silencing of Mst1 expression by short hairpin RNA(shRNA)adenovirus transfection.Integrin(ITGs)were tested by flow cytometry.Autophagy and ITGα5β1 were inhibited using 3-methyladenine and small interfering RNA,respe-ctively.The alterations in anoikis were measured by Terminal-deoxynucleoitidyl Transferase Mediated Nick End Labeling and anoikis assays.The levels of the anoikis-related proteins ITGα5,ITGβ1,and phospho-focal adhesion kinase and the activation of caspase 3 and the autophagy-related proteins microtubules associated protein 1 light chain 3 II/I,Beclin1 and p62 were detected by Western blotting.RESULTS In isolated mBMSCs,Mst1 expression was upregulated,and Mst1 inhibition significantly reduced cell apoptosis,induced autophagy and decreased ROS levels.Mechanistically,we found that Mst1 inhibition could upregulate ITGα5 and ITGβ1 expression but not ITGα4,ITGαv,or ITGβ3 expression.Moreover,autophagy induced by upregulated ITGα5β1 expression following Mst1 inhibition played an essential role in the protective efficacy of Mst1 inhibition in averting anoikis.CONCLUSION Mst1 inhibition ameliorated autophagy formation,increased ITGα5β1 expression,and decreased the excessive production of ROS,thereby reducing cell apoptosis in isolated mBMSCs.Based on these results,Mst1 inhibition may provide a promising strategy to overcome anoikis of implanted MSCs.展开更多
目的:探讨MST1(mammalian sterile 20-like kinase 1)在同型半胱氨酸(homocysteine,Hcy)促肝细胞凋亡中的作用.方法:动物水平:实验分为4组,每组12只小鼠.正常对照组:5周龄♂鼠(SPF级C57BL/6J)饲以普通饮食;Apo E-/-对照组:5周龄♂纯合子...目的:探讨MST1(mammalian sterile 20-like kinase 1)在同型半胱氨酸(homocysteine,Hcy)促肝细胞凋亡中的作用.方法:动物水平:实验分为4组,每组12只小鼠.正常对照组:5周龄♂鼠(SPF级C57BL/6J)饲以普通饮食;Apo E-/-对照组:5周龄♂纯合子Apo E-/-鼠饲以普通饮食;Apo E-/-高蛋氨酸组:5周龄♂纯合子Apo E-/-鼠饲以高蛋氨酸饮食(普通饮食中加入1.7%蛋氨酸);Apo E-/-叶酸和维生素B12干预组:5周龄♂纯合子A p o E-/-鼠饲以高蛋氨酸饮食加0.006%叶酸和0.0004%维生素B12.喂养14 wk后,全自动生化分析仪测定血清Hcy水平;透射电镜、DAPI染色观察肝组织凋亡情况;实时定量聚合酶链反应(q RT-PCR)及Western blot分别检测MST1 m RNA和蛋白表达水平.细胞水平:分为3组:正常对照组(0μmol/L Hcy);高同型半胱氨酸(hyperhomocysteinemia,HHcy)组(100μmol/L Hcy);干预组(100μmol/L Hcy+叶酸+维生素B12);干预肝细胞48 h.Annexin VFITC/PI双标记流式细胞术检测肝细胞凋亡水平的变化;实时定量聚合酶链反应(q RTPCR)及Western blot分别检测MST1 m RNA和蛋白表达水平.结果:动物水平:(1)各组小鼠喂养20 wk后,测定血清Hcy水平,Apo E-/-高蛋氨酸组血清H c y水平分别是正常对照组和A p o E-/-对照组的2.3倍和1.9倍(P<0.01).干预组血清Hcy水平较Apo E-/-高蛋氨酸组降低28%(P<0.01),提示造HHcy模型成功;(2)电镜结果显示,A p o E-/-高蛋氨酸组小鼠肝细胞出现凋亡的倾向,染色质凝聚浓缩或边缘化,线粒体肿胀或浓缩、嵴断裂或变短,粗面内质网和滑面内质网明显肿胀、断裂、连贯性破坏、核糖体脱落,糖原溶解;(3)DAPI染色后观察,正常对照组和Apo E-/-对照组中细胞核大小均一、核圆,核膜光滑;Apo E-/-高蛋氨酸饮食组一些细胞出现核膜皱缩、细胞核呈现出各种不规则形状,提示可能存在凋亡;Apo E-/-干预组较Apo E-/-高蛋氨酸组细胞核损伤有所减轻;(4)与正常对照组和Apo E-/-对照组相比,Apo E-/-高蛋氨酸组肝组织MST1 m RNA及蛋白表达水平增高(P<0.05或P<0.01),A p o E-/-干预组肝细胞MST1 m RNA及蛋白表达水平较A p o E-/-高蛋氨酸组有所降低(P<0.05).细胞水平:(1)与正常对照组相比,HHcy组肝细胞凋亡水平增高(P<0.01),干预组较HHcy组有所减轻(P<0.05);(2)与正常对照组相比,HHcy组肝细胞MST1 m RNA及蛋白表达水平增高(P<0.01),干预组肝细胞MST1 m RNA及蛋白表达水平较HHcy组有所降低(P<0.05).结论:在HHcy促肝细胞凋亡过程中MST1表达上调,且叶酸和维生素B12可以抑制其表达上调.展开更多
Primary immune thrombocytopenia(ITP)is an autoimmune hemorrhagic disorder in which macrophages play a critical role.Mammalian sterile-20-like kinase 4(MST4),a member of the germinal-center kinase STE20 family,has been...Primary immune thrombocytopenia(ITP)is an autoimmune hemorrhagic disorder in which macrophages play a critical role.Mammalian sterile-20-like kinase 4(MST4),a member of the germinal-center kinase STE20 family,has been demonstrated to be a regulator of inflammation.Whether MST4 participates in the macrophage-dependent inflammation of ITP remains elusive.The expression and function of MST4 in macrophages of ITP patients and THP-1 cells,and of a macrophage-specific Mst4−/−(Mst4ΔM/ΔM)ITP mouse model were determined.Macrophage phagocytic assays,RNA sequencing(RNA-seq)analysis,immunofluorescence analysis,coimmunoprecipitation(co-IP),mass spectrometry(MS),bioinformatics analysis,and phosphoproteomics analysis were performed to reveal the underlying mechanisms.The expression levels of the MST4 gene were elevated in the expanded M1-like macrophages of ITP patients,and this elevated expression of MST4 was restored to basal levels in patients with remission after high-dose dexamethasone treatment.The expression of the MST4 gene was significantly elevated in THP-1-derived M1 macrophages.Silencing of MST4 decreased the expression of M1 macrophage markers and cytokines,and impaired phagocytosis,which could be increased by overexpression of MST4.In a passive ITP mouse model,macrophage-specific depletion of Mst4 reduced the numbers of M1 macrophages in the spleen and peritoneal lavage fluid,attenuated the expression of M1 cytokines,and promoted the predominance of FcγRIIb in splenic macrophages,which resulted in amelioration of thrombocytopenia.Downregulation of MST4 directly inhibited STAT1 phosphorylation,which is essential for M1 polarization of macrophages.Our study elucidates a critical role for MST4 kinase in the pathology of ITP and identifies MST4 kinase as a potential therapeutic target for refractory ITP.展开更多
基金Supported by Natural Science Foundation of Shandong Province,China,No.ZR2020MH014,No.ZR2021QH179 and No.ZR2021MH182.
文摘BACKGROUND The low survival rate of mesenchymal stem cells(MSCs)caused by anoikis,a form of apoptosis,limits the therapeutic efficacy of MSCs.As a proapoptotic molecule,mammalian Ste20-like kinase 1(Mst1)can increase the production of reactive oxygen species(ROS),thereby promoting anoikis.Recently,we found that Mst1 inhibition could protect mouse bone marrow MSCs(mBMSCs)from H 2 O 2-induced cell apoptosis by inducing autophagy and reducing ROS production.However,the influence of Mst1 inhibition on anoikis in mBMSCs remains unclear.AIM To investigate the mechanisms by which Mst1 inhibition acts on anoikis in isolated mBMSCs.METHODS Poly-2-hydroxyethyl methacrylate-induced anoikis was used following the silencing of Mst1 expression by short hairpin RNA(shRNA)adenovirus transfection.Integrin(ITGs)were tested by flow cytometry.Autophagy and ITGα5β1 were inhibited using 3-methyladenine and small interfering RNA,respe-ctively.The alterations in anoikis were measured by Terminal-deoxynucleoitidyl Transferase Mediated Nick End Labeling and anoikis assays.The levels of the anoikis-related proteins ITGα5,ITGβ1,and phospho-focal adhesion kinase and the activation of caspase 3 and the autophagy-related proteins microtubules associated protein 1 light chain 3 II/I,Beclin1 and p62 were detected by Western blotting.RESULTS In isolated mBMSCs,Mst1 expression was upregulated,and Mst1 inhibition significantly reduced cell apoptosis,induced autophagy and decreased ROS levels.Mechanistically,we found that Mst1 inhibition could upregulate ITGα5 and ITGβ1 expression but not ITGα4,ITGαv,or ITGβ3 expression.Moreover,autophagy induced by upregulated ITGα5β1 expression following Mst1 inhibition played an essential role in the protective efficacy of Mst1 inhibition in averting anoikis.CONCLUSION Mst1 inhibition ameliorated autophagy formation,increased ITGα5β1 expression,and decreased the excessive production of ROS,thereby reducing cell apoptosis in isolated mBMSCs.Based on these results,Mst1 inhibition may provide a promising strategy to overcome anoikis of implanted MSCs.
文摘目的:探讨MST1(mammalian sterile 20-like kinase 1)在同型半胱氨酸(homocysteine,Hcy)促肝细胞凋亡中的作用.方法:动物水平:实验分为4组,每组12只小鼠.正常对照组:5周龄♂鼠(SPF级C57BL/6J)饲以普通饮食;Apo E-/-对照组:5周龄♂纯合子Apo E-/-鼠饲以普通饮食;Apo E-/-高蛋氨酸组:5周龄♂纯合子Apo E-/-鼠饲以高蛋氨酸饮食(普通饮食中加入1.7%蛋氨酸);Apo E-/-叶酸和维生素B12干预组:5周龄♂纯合子A p o E-/-鼠饲以高蛋氨酸饮食加0.006%叶酸和0.0004%维生素B12.喂养14 wk后,全自动生化分析仪测定血清Hcy水平;透射电镜、DAPI染色观察肝组织凋亡情况;实时定量聚合酶链反应(q RT-PCR)及Western blot分别检测MST1 m RNA和蛋白表达水平.细胞水平:分为3组:正常对照组(0μmol/L Hcy);高同型半胱氨酸(hyperhomocysteinemia,HHcy)组(100μmol/L Hcy);干预组(100μmol/L Hcy+叶酸+维生素B12);干预肝细胞48 h.Annexin VFITC/PI双标记流式细胞术检测肝细胞凋亡水平的变化;实时定量聚合酶链反应(q RTPCR)及Western blot分别检测MST1 m RNA和蛋白表达水平.结果:动物水平:(1)各组小鼠喂养20 wk后,测定血清Hcy水平,Apo E-/-高蛋氨酸组血清H c y水平分别是正常对照组和A p o E-/-对照组的2.3倍和1.9倍(P<0.01).干预组血清Hcy水平较Apo E-/-高蛋氨酸组降低28%(P<0.01),提示造HHcy模型成功;(2)电镜结果显示,A p o E-/-高蛋氨酸组小鼠肝细胞出现凋亡的倾向,染色质凝聚浓缩或边缘化,线粒体肿胀或浓缩、嵴断裂或变短,粗面内质网和滑面内质网明显肿胀、断裂、连贯性破坏、核糖体脱落,糖原溶解;(3)DAPI染色后观察,正常对照组和Apo E-/-对照组中细胞核大小均一、核圆,核膜光滑;Apo E-/-高蛋氨酸饮食组一些细胞出现核膜皱缩、细胞核呈现出各种不规则形状,提示可能存在凋亡;Apo E-/-干预组较Apo E-/-高蛋氨酸组细胞核损伤有所减轻;(4)与正常对照组和Apo E-/-对照组相比,Apo E-/-高蛋氨酸组肝组织MST1 m RNA及蛋白表达水平增高(P<0.05或P<0.01),A p o E-/-干预组肝细胞MST1 m RNA及蛋白表达水平较A p o E-/-高蛋氨酸组有所降低(P<0.05).细胞水平:(1)与正常对照组相比,HHcy组肝细胞凋亡水平增高(P<0.01),干预组较HHcy组有所减轻(P<0.05);(2)与正常对照组相比,HHcy组肝细胞MST1 m RNA及蛋白表达水平增高(P<0.01),干预组肝细胞MST1 m RNA及蛋白表达水平较HHcy组有所降低(P<0.05).结论:在HHcy促肝细胞凋亡过程中MST1表达上调,且叶酸和维生素B12可以抑制其表达上调.
基金supported by grants from the National Natural Science Foundation of China(82370130,81870098,82300146)the Program of the Shanghai Academic/Technology Researcher Leader(20XD1401000)+2 种基金the Shanghai Engineering Research Center of Tumor Multi-Target Gene Diagnosis(20DZ2254300)the Key Subject Construction Program of the Shanghai Health Administrative Authority(ZK2019B30)the Science and Technology Commission of the Shanghai Municipality(21ZR1459000).
文摘Primary immune thrombocytopenia(ITP)is an autoimmune hemorrhagic disorder in which macrophages play a critical role.Mammalian sterile-20-like kinase 4(MST4),a member of the germinal-center kinase STE20 family,has been demonstrated to be a regulator of inflammation.Whether MST4 participates in the macrophage-dependent inflammation of ITP remains elusive.The expression and function of MST4 in macrophages of ITP patients and THP-1 cells,and of a macrophage-specific Mst4−/−(Mst4ΔM/ΔM)ITP mouse model were determined.Macrophage phagocytic assays,RNA sequencing(RNA-seq)analysis,immunofluorescence analysis,coimmunoprecipitation(co-IP),mass spectrometry(MS),bioinformatics analysis,and phosphoproteomics analysis were performed to reveal the underlying mechanisms.The expression levels of the MST4 gene were elevated in the expanded M1-like macrophages of ITP patients,and this elevated expression of MST4 was restored to basal levels in patients with remission after high-dose dexamethasone treatment.The expression of the MST4 gene was significantly elevated in THP-1-derived M1 macrophages.Silencing of MST4 decreased the expression of M1 macrophage markers and cytokines,and impaired phagocytosis,which could be increased by overexpression of MST4.In a passive ITP mouse model,macrophage-specific depletion of Mst4 reduced the numbers of M1 macrophages in the spleen and peritoneal lavage fluid,attenuated the expression of M1 cytokines,and promoted the predominance of FcγRIIb in splenic macrophages,which resulted in amelioration of thrombocytopenia.Downregulation of MST4 directly inhibited STAT1 phosphorylation,which is essential for M1 polarization of macrophages.Our study elucidates a critical role for MST4 kinase in the pathology of ITP and identifies MST4 kinase as a potential therapeutic target for refractory ITP.
