HBx transfection limits proliferative capacity of podocytes through cell cycle regulation  

作　　者：Yu Zhang Yu Chen Fengjie Yang Jianhua Zhou 

机构地区：[1]Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China

出　　处：《Acta Biochimica et Biophysica Sinica》2014年第12期1016-1023,共8页生物化学与生物物理学报（英文版）

基　　金：This work was supported by the grants from the National Natural Science Foundation of China （81070557, 81100514）.

摘　　要：Our previous studies have shown that podocyte number is significantly decreased in glomeruli of children with hepa- titis B virus （HBV）-associated glomerulonephritis. In this study, we aimed to explore whether exogenous expression of HBx protein could directly inhibit podocyte proliferation in vitro, and to investigate its role in cell cycle regulation. HBx gene was delivered into cultured mouse podocytes through an adenovirus-based vector. Cell morphology was evaluated with Wright-Giemsa staining. Cell growth and proliferation were measured by 3-（4,5-dimethylthiazol-2-yl）- 2,5-diphenyltetrazolium bromide （MTT） and 5,6-carboxy- fluorescein diacetate, succinimidyl ester （CFSE）-based pro- liferation assays. Cell cycle phase was analyzed by flow cytometry, and the expression of cell cycle regulatory pro- teins was examined by western blot analysis. It was found that the aberrant nuclear changes like double and multiple micronuclei, which reflect mitotic catastrophe, accumulated in podocytes after 5 days post-infection. MTT assay showed that Ad.HBx-infected podocytes grew much more slowly than controls at day 4 post-infection and thereafter. Furthermore, CFSE-based proliferation assay also showed that the prolifer- ation of HBx-expressing podocytes was significantly inhibited than that of controls at 3-day post-infection, and that the dif- ference became much more obvious at day 5 post-infection. Cell cycle analysis showed that the transfection of HBx resulted in significant up-regulation of both cyclin B1 and CDK-inhibitor p21 expression and G2/M phase arrest, and slight down-regulation of cyclin A expression. These results demonstrated that exogenous expression of HBx might limit the proliferative capacity of podocytes through cell cycle regu- lation, thus suggesting that HBx may play a role in podocyte injuries in HBV-associated glomerulonephritis.Our previous studies have shown that podocyte number is significantly decreased in glomeruli of children with hepa- titis B virus （HBV）-associated glomerulonephritis. In this study, we aimed to explore whether exogenous expression of HBx protein could directly inhibit podocyte proliferation in vitro, and to investigate its role in cell cycle regulation. HBx gene was delivered into cultured mouse podocytes through an adenovirus-based vector. Cell morphology was evaluated with Wright-Giemsa staining. Cell growth and proliferation were measured by 3-（4,5-dimethylthiazol-2-yl）- 2,5-diphenyltetrazolium bromide （MTT） and 5,6-carboxy- fluorescein diacetate, succinimidyl ester （CFSE）-based pro- liferation assays. Cell cycle phase was analyzed by flow cytometry, and the expression of cell cycle regulatory pro- teins was examined by western blot analysis. It was found that the aberrant nuclear changes like double and multiple micronuclei, which reflect mitotic catastrophe, accumulated in podocytes after 5 days post-infection. MTT assay showed that Ad.HBx-infected podocytes grew much more slowly than controls at day 4 post-infection and thereafter. Furthermore, CFSE-based proliferation assay also showed that the prolifer- ation of HBx-expressing podocytes was significantly inhibited than that of controls at 3-day post-infection, and that the dif- ference became much more obvious at day 5 post-infection. Cell cycle analysis showed that the transfection of HBx resulted in significant up-regulation of both cyclin B1 and CDK-inhibitor p21 expression and G2/M phase arrest, and slight down-regulation of cyclin A expression. These results demonstrated that exogenous expression of HBx might limit the proliferative capacity of podocytes through cell cycle regu- lation, thus suggesting that HBx may play a role in podocyte injuries in HBV-associated glomerulonephritis.

关 键 词：hepatitis B virus X protein PODOCYTE cell cycle HBV-associated glomemlonephritis 

分 类 号：Q253[生物学—细胞生物学] S858.315.3[农业科学—临床兽医学]