高密度脂蛋白亚类与蛋白激酶C活性的关系  

High density lipoprotein subclasses and activities of protein kinase C

作　　者：徐燕华[1] 傅明德[1] 

机构地区：[1]四川大学基础医学与法医学院生物化学与分子生物学教研室,四川成都610041

出　　处：《中国病理生理杂志》2005年第1期45-49,共5页Chinese Journal of Pathophysiology

基　　金：美国纽约中华医学基金会(CMB)资助课题(No.82-412)

摘　　要：目的观察高密度脂蛋白(HDL)亚类与外周细胞和肝细胞HDL受体结合活性及细胞PKC活性的关系。方法以纯化的前β1-HDL及不含apoE的HDL3为配体,分别与人动脉平滑肌细胞(SMC)和肝癌细胞系HepG2反应,观察两种细胞HDL受体结合活性及细胞PKC活性的变化。结果前β1-HDL与SMCHDL受体的亲和力不仅显著高于不含apoE的HDL3与SMCHDL受体的亲和力(P<005),而且还显著高于它与HepG2细胞HDL受体的亲和力(P<005);前β1-HDL和不含apoE的HDL3分别与SMC反应后,均可激活细胞PKC信号传递途径,且前β1-HDL的作用较不含apoE的HDL3更为明显;而这二种HDL亚类分别与HepG2细胞反应后,细胞PKC活性均无明显变化。结论前β1-HDL似乎可以比不含apoE的HDL3更为有效的促进细胞胆固醇移出,而且血浆中前β1-HDL可能更多地作用于外周细胞如SMC,并通过外周细胞膜上的HDL受体介导激活PKC信号传递途径,从而促进外周细胞中过剩的胆固醇移出,而肝细胞HDL受体介导的胆固醇进入细胞可能与PKC信号途径无关。AIM: To investigate the relationship between high density lipoprotein (HDL) subclasses and the binding activities of hepatic cell and extra-hepatic cell HDL receptor and intracellular protein kinase C (PKC). METHODS: Using purified pre-β_1 HDL and apoE-deficent HDL_3 to react with human smooth muscle cells (SMC) and HepG2 cells, then the activities of pre-β_1HDL and apoE-deficent HDL_3 binding to SMC and HepG2 cells, and the effects of this two HDL subclasses on PKC activities in SMC and HepG2 cells were observed . RESULTS: The results showed that the value of Kd of pre-β_1HDL binding to SMC HDL receptor was not only significantly lower than that of apoE-deficient HDL_3 (P<0.05), but significantly lower than pre-β_1 HDL binding to HepG2 HDL receptor (P<0.05). Cell PKC system was all activated by binding of the two HDL subclasses with SMC HDL receptor, and the effect of pre-β_1HDL appeared to be stronger than apoE-deficent HDL_3. No change in HepG2 cell PKC activity by binding the two HDL subclasses with HepG2 HDL receptor was observed. CONCLUSIONS: The results indicate that the ability of pre-β_1HDL to promote efflux of cholesterol from extra-hepatic cells is stronger than that of apoE-deficent HDL_3, and it seems that plasma pre-β_1 HDL mainly interacts with extra-hepatic cell HDL receptor, subsequently, activates PKC signal transduction system and promotes the intracellular cholesterol efflux from cells. [

关 键 词：脂蛋白类 HDL 受体 脂蛋白 蛋白激酶C 平滑肌细胞 HEPG2细胞 

分 类 号：R363[医药卫生—病理学]