Onychin inhibits proliferation of vascular smooth muscle cells by regulating cell cycle  

作　　者：Ming YANG Hong-lin HUANG Bing-yang ZHU Qin-hui TUO Duan-fang LIAO 

机构地区：[1]Institute of Pharmacy and Pharmacology,Nanhua University,Hengyang 421001,China

出　　处：《Acta Pharmacologica Sinica》2005年第2期205-211,共7页中国药理学报（英文版）

基　　金：Project supported by grants from the State Key Basic Research and Development Program of China(973:No G2000056905);the National Natural Science Foundation of China(No.39970847,30171084);the Natural Science Foundation of Hunan(No.03JJY3037)

摘　　要：Aim:To investigate the effects of onychin on the proliferation of cultured rat artery vascular smooth muscle cells(VSMCs)in the presence of 10% new-born calf serum(NCS).Methods:Rat VSMCs were incubated with onychin 1-50 μmol/L or genistein 10μmol/L in the presence of 10% NCS for 24 h.The prolif- eration of VSMCs was measured by cell counting and MTS/PMS colorimetric assays.Cell cycle progression was evaluated by flow cytometry.Retinoblastoma (Rb)phosphorylation,and expression of cyclin D_1 and cyclin E were measured by Western blot assays.The tyrosine phosphorylation of ERK1/2 was examined by immunoprecipitation techniques using anti-phospho-tyrosine antibodies.Results: The proliferation of VSMCs was accelerated significantly in the presence of 10% NCS.Onychin reduced the metabolic rate of MTS and the cell number of VSMCs in the presence of 10% NCS in a dose-dependent manner.Flow cytometry analy- sis revealed that the G_1-phase fraction ratio in the onychin group was higher than that in the 10% NCS group(85.2% vs 70.0%,P<0.01),while the S-phase fraction ratio in the onychin group was lower than that in 10% NCS group(4.3% vs 16.4%,P<0.01).Western blot analysis showed that onychin inhibited Rb phos- phorylation and reduced the expression of cyclin D_1 and cyclin E.The effects of onychin on proliferation,the cell cycle and the expression of cyclins in VSMCs were similar to those of genistein,an inhibitor of tyrosine kinase.Furthermore immunoprecipitation studies showed that both onychin and genistein markedly inhibited the tyrosine phosphorylation of ERK1/2 induced by 10% NCS. Conclusion:Onychin inhibits the proliferation of VSMCs through G_1 phase cell cycle arrest by decreasing the tyrosine phosphorylation of ERK1/2,and the ex- pression of cyclin D_1 and cyclin E,and sequentially inhibiting Rb phosphorylation.Aim:To investigate the effects of onychin on the proliferation of cultured rat artery vascular smooth muscle cells(VSMCs)in the presence of 10% new-born calf serum(NCS).Methods:Rat VSMCs were incubated with onychin 1-50 μmol/L or genistein 10μmol/L in the presence of 10% NCS for 24 h.The prolif- eration of VSMCs was measured by cell counting and MTS/PMS colorimetric assays.Cell cycle progression was evaluated by flow cytometry.Retinoblastoma (Rb)phosphorylation,and expression of cyclin D_1 and cyclin E were measured by Western blot assays.The tyrosine phosphorylation of ERK1/2 was examined by immunoprecipitation techniques using anti-phospho-tyrosine antibodies.Results: The proliferation of VSMCs was accelerated significantly in the presence of 10% NCS.Onychin reduced the metabolic rate of MTS and the cell number of VSMCs in the presence of 10% NCS in a dose-dependent manner.Flow cytometry analy- sis revealed that the G_1-phase fraction ratio in the onychin group was higher than that in the 10% NCS group(85.2% vs 70.0%,P<0.01),while the S-phase fraction ratio in the onychin group was lower than that in 10% NCS group(4.3% vs 16.4%,P<0.01).Western blot analysis showed that onychin inhibited Rb phos- phorylation and reduced the expression of cyclin D_1 and cyclin E.The effects of onychin on proliferation,the cell cycle and the expression of cyclins in VSMCs were similar to those of genistein,an inhibitor of tyrosine kinase.Furthermore immunoprecipitation studies showed that both onychin and genistein markedly inhibited the tyrosine phosphorylation of ERK1/2 induced by 10% NCS. Conclusion:Onychin inhibits the proliferation of VSMCs through G_1 phase cell cycle arrest by decreasing the tyrosine phosphorylation of ERK1/2,and the ex- pression of cyclin D_1 and cyclin E,and sequentially inhibiting Rb phosphorylation.

关 键 词：onychin vascular smooth muscle cell cycle RETINOBLASTOMA cyclin D1 cyclin E tyrosine kinase mitogen-activated protein kmase 

分 类 号：R977.3[医药卫生—药品]