前期研究发现骨形态发生蛋白9(bone morphogenetic protein 9,BMP9)除了通过经典Smad途径外,也可通过丝裂原活化蛋白激酶(mitogen activated protein kinases,MAPKs)中的p38激酶途径调控间充质干细胞成骨分化.本研究继续探讨MAPKs的重...前期研究发现骨形态发生蛋白9(bone morphogenetic protein 9,BMP9)除了通过经典Smad途径外,也可通过丝裂原活化蛋白激酶(mitogen activated protein kinases,MAPKs)中的p38激酶途径调控间充质干细胞成骨分化.本研究继续探讨MAPKs的重要成员c-Jun氨基末端激酶(c-Jun N-terminal kinases,JNKs)对于BMP9诱导间充质干细胞成骨分化的调控作用.利用BMP9重组腺病毒感染间充质干细胞,通过体外细胞实验和体内动物实验,初步分析BMP9是否可通过JNKs激酶途径调控间充质干细胞成骨分化.结果表明:BMP9可通过促进JNKs激酶磷酸化而导致其活化;JNKs抑制剂SP600125可抑制由BMP9诱导的间充质干细胞的碱性磷酸酶(alkaline phosphatase,ALP)活性、骨桥蛋白(osteocpontin,OPN)和骨钙素(osteocalcin,OCN)表达以及钙盐沉积;利用抑制剂SP600125抑制JNKs激酶活性后,BMP9诱导Runx2的表达和转录活性,以及Smad经典途径的激活也相应受到抑制;RNA干扰导致JNKs基因沉默同样也可抑制BMP9诱导的间充质干细胞成骨分化以及裸鼠皮下异位成骨.因此,BMP9可通过活化JNKs激酶途径,从而调控间充质干细胞成骨分化.展开更多
BACKGROUND Human spermatogonial stem cells(SSCs)are the basis of spermatogenesis.However,little is known about the developmental regulatory mechanisms of SSC due to sample origin and species differences.AIM To investi...BACKGROUND Human spermatogonial stem cells(SSCs)are the basis of spermatogenesis.However,little is known about the developmental regulatory mechanisms of SSC due to sample origin and species differences.AIM To investigates the mechanisms involved in the proliferation of human SSC.METHODS The expression of mitogen-activated protein kinase kinase 7(MKK7)in human testis was identified using immunohistochemistry and western blotting(WB).MKK7 was knocked down using small interfering RNA,and cell proliferation and apoptosis were detected by WB,EdU,cell counting kit-8 and fluorescenceactivated cell sorting.After bioinformatic analysis,the interaction of MKK7 with c-Jun N-terminal kinases(JNKs)was verified by protein co-immunoprecipitation and WB.The phosphorylation of JNKs was inhibited by SP600125,and the phenotypic changes were detected by WB,cell counting kit-8 and fluorescenceactivated cell sorting.RESULTS MKK7 is mainly expressed in human SSCs,and MKK7 knockdown inhibits SSC proliferation and promotes their apoptosis.MKK7 mediated the phosphorylation of JNKs,and after inhibiting the phosphorylation of JNKs,the phenotypic changes of the cells were similar to those after MKK7 downregulation.The expression of MKK7 was significantly downregulated in patients with abnormal spermatogenesis,suggesting that abnormal MKK7 may be associated with spermatogenesis impairment.CONCLUSION MKK7 regulates the proliferation and apoptosis of human SSC by mediating the phosphorylation of JNKs.展开更多
Curcumin,a natural polyphenol obtained from turmeric,has been implicated to be neuroprotective in a variety of neurodegenerative disorders although the mechanism remains poorly understood.The results of our recent exp...Curcumin,a natural polyphenol obtained from turmeric,has been implicated to be neuroprotective in a variety of neurodegenerative disorders although the mechanism remains poorly understood.The results of our recent experiments indicated that curcumin could protect dopaminergic neurons from apoptosis in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)mouse model of Parkinson’s disease(PD).The death of dopaminergic neurons and the loss of dopaminergic axon in the striatum were significantly suppressed by curcumin in MPTP mouse model.Further studies showed that curcumin inhibited JNKs hyperphosphorylation induced by MPTP treatment.JNKs phosphorylation can cause translocation of Bax to mitochondria and the release of cytochrome c which both ultimately contribute to mitochondria-mediated apoptosis.These pro-apoptosis effect can be diminished by curcumin.Our experiments demonstrated that curcumin can prevent nigrostriatal degeneration by inhibiting the dysfunction of mitochondrial through suppressing hyperphosphorylation of JNKs induced by MPTP.Our results suggested that JNKs/mitochondria pathway may be a novel target in the treatment of PD patients.展开更多
文摘前期研究发现骨形态发生蛋白9(bone morphogenetic protein 9,BMP9)除了通过经典Smad途径外,也可通过丝裂原活化蛋白激酶(mitogen activated protein kinases,MAPKs)中的p38激酶途径调控间充质干细胞成骨分化.本研究继续探讨MAPKs的重要成员c-Jun氨基末端激酶(c-Jun N-terminal kinases,JNKs)对于BMP9诱导间充质干细胞成骨分化的调控作用.利用BMP9重组腺病毒感染间充质干细胞,通过体外细胞实验和体内动物实验,初步分析BMP9是否可通过JNKs激酶途径调控间充质干细胞成骨分化.结果表明:BMP9可通过促进JNKs激酶磷酸化而导致其活化;JNKs抑制剂SP600125可抑制由BMP9诱导的间充质干细胞的碱性磷酸酶(alkaline phosphatase,ALP)活性、骨桥蛋白(osteocpontin,OPN)和骨钙素(osteocalcin,OCN)表达以及钙盐沉积;利用抑制剂SP600125抑制JNKs激酶活性后,BMP9诱导Runx2的表达和转录活性,以及Smad经典途径的激活也相应受到抑制;RNA干扰导致JNKs基因沉默同样也可抑制BMP9诱导的间充质干细胞成骨分化以及裸鼠皮下异位成骨.因此,BMP9可通过活化JNKs激酶途径,从而调控间充质干细胞成骨分化.
基金Supported by China Postdoctoral Science Foundation,No.2019M661521and National Natural Science Foundation of China,No.82001634.
文摘BACKGROUND Human spermatogonial stem cells(SSCs)are the basis of spermatogenesis.However,little is known about the developmental regulatory mechanisms of SSC due to sample origin and species differences.AIM To investigates the mechanisms involved in the proliferation of human SSC.METHODS The expression of mitogen-activated protein kinase kinase 7(MKK7)in human testis was identified using immunohistochemistry and western blotting(WB).MKK7 was knocked down using small interfering RNA,and cell proliferation and apoptosis were detected by WB,EdU,cell counting kit-8 and fluorescenceactivated cell sorting.After bioinformatic analysis,the interaction of MKK7 with c-Jun N-terminal kinases(JNKs)was verified by protein co-immunoprecipitation and WB.The phosphorylation of JNKs was inhibited by SP600125,and the phenotypic changes were detected by WB,cell counting kit-8 and fluorescenceactivated cell sorting.RESULTS MKK7 is mainly expressed in human SSCs,and MKK7 knockdown inhibits SSC proliferation and promotes their apoptosis.MKK7 mediated the phosphorylation of JNKs,and after inhibiting the phosphorylation of JNKs,the phenotypic changes of the cells were similar to those after MKK7 downregulation.The expression of MKK7 was significantly downregulated in patients with abnormal spermatogenesis,suggesting that abnormal MKK7 may be associated with spermatogenesis impairment.CONCLUSION MKK7 regulates the proliferation and apoptosis of human SSC by mediating the phosphorylation of JNKs.
文摘目的 基于c-Jun氨基末端激酶(JNK)-p62/螯合体(SQSTM1)信号通路探讨糖肾煎对2型糖尿病肾病(DN)大鼠足细胞的保护作用。方法 SD大鼠随机分成正常组、DN组、糖肾煎低、中、高[生药5、10、20 g/(kg·d)]剂量组(糖肾煎-L、M、H组)、二甲双胍组[100 mg/(kg·d)]。除正常组外,其余各组通过喂养高脂高糖饲料和腹腔注射链脲佐菌素(STZ)进行DN模型构建。药物干预结束后,检测大鼠血生化指标空腹血糖(FBG)、负荷后2 h血糖(P2 h BG)、血肌酐(SCr)、血尿素氮(BUN)水平;苏木素-伊红(HE)、六胺银(PASM)染色观察肾组织病理学变化;透射电镜(TEM)观察肾小球基底膜损伤和足细胞变化情况;Western印迹检测肾组织中微管相关蛋白1A/1B-轻链(LC)3、p-JNK、JNK、p62/SQSTM1、肾病蛋白(Nephrin)蛋白表达。结果 与正常组比较,DN组FBG、P2 h BG、SCr、BUN水平及p62/SQSTM1蛋白表达明显升高,LC3-Ⅱ、Nephrin蛋白表达和p-JNK/JNK明显降低(P<0.05);光镜下观察到肾小球缩小、管丛系膜明显扩张,并有基底膜增生增厚等现象;TEM下观察到肾小球基底膜增厚、足细胞排列紊乱、形态改变、足突融合等现象。与DN组比较,糖肾煎-L、M、H组和二甲双胍组FBG、P2 h BG、SCr、BUN水平及p62/SQSTM1蛋白表达明显降低,LC3-Ⅱ、Nephrin蛋白表达和p-JNK/JNK明显升高(P<0.05);并且肾小球基底膜增厚、足细胞足突融合等情况均获得一定程度减轻。结论 糖肾煎对2型DN大鼠足细胞具有一定保护作用,可能是通过调控JNK-p62/SQSTM1信号通路,提高足细胞自噬,从而起到肾脏保护功效。
基金This work was supported by grants from the National Program of Basic Research(2010CB945200,2011CB504104)of ChinaNational Natural Science Fund(34900454,30900454,30971031)+4 种基金Key Discipline Program of Shanghai Municipality(S30202)Shanghai Key Project of Basic Science Research(10411954500)Program for Outstanding Medical Academic Leader(LJ 06003)Research Fund for the Doctoral Program of Higher Education of China(20090073120090)Special funding for original sci-tech research supported by Shanghai Municipal Education Commission(09YZ87).
文摘Curcumin,a natural polyphenol obtained from turmeric,has been implicated to be neuroprotective in a variety of neurodegenerative disorders although the mechanism remains poorly understood.The results of our recent experiments indicated that curcumin could protect dopaminergic neurons from apoptosis in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)mouse model of Parkinson’s disease(PD).The death of dopaminergic neurons and the loss of dopaminergic axon in the striatum were significantly suppressed by curcumin in MPTP mouse model.Further studies showed that curcumin inhibited JNKs hyperphosphorylation induced by MPTP treatment.JNKs phosphorylation can cause translocation of Bax to mitochondria and the release of cytochrome c which both ultimately contribute to mitochondria-mediated apoptosis.These pro-apoptosis effect can be diminished by curcumin.Our experiments demonstrated that curcumin can prevent nigrostriatal degeneration by inhibiting the dysfunction of mitochondrial through suppressing hyperphosphorylation of JNKs induced by MPTP.Our results suggested that JNKs/mitochondria pathway may be a novel target in the treatment of PD patients.
