VLDL促进脂蛋白脂酶在人肾小球系膜细胞系的表达

VLDL promotes the expression of lipoprotein lipase in human glomerular mesangial cells

目的探讨人肾小球系膜细胞脂蛋白脂酶（LPL）的表达情况以及极低密度脂蛋白（VLDL）对其表达的影响。方法用反转录聚合酶链反应（RT—PCR）、Western blot和放射性同位素标记的脂质体底物法检测人肾小球系膜细胞系（HMCLs）LPL mRNA表达、蛋白合成及酶活性。Western blot检测VLDL对肾小球系膜细胞LPL表达的影响。结果用HMCLs，在276bp处可扩增出一条hLPL基因特异的条带；在55kd处可检测出LPL蛋白特异的条带；经肝素释放后HMCLs培养液中LPL是有活性的，为（0．959±0．022）U／L。VLDL在一定范围内可时间（0—16h）和剂量（0～100mg／L）依赖性的刺激HMCL sLPL蛋白表达。结论在肾小球系膜细胞可表达具有活性的脂蛋白脂酶，且其表达可受VLDL的调节。

Objective To study the expression of lipoprotein lipase （LPL） in human glomerular mesangial cells and the effect of very low-density lipoprotein （VLDL） on the expression of LPL. Methods LPL mRNA expression, protein synthesis and activity were detected in human glomerular mesangial cells by RT-PCR, Westem blot and a radiochemical analysis respectively. Effect of VLDL on the expression of LPL in mesangial cells was detected by Western blot. Results In human glomerular mesangial ceils, a 276 bp band, that was specific for human LPL, was identified by RT-PCR, and the same of a 55 kd band, specific for human LPL by western blot. LPL activity of mesangial cells was also detected in the medium after release by heparin. VLDL stimulated LPL protein synthesis in mesangial cells in a time-and dose-dependent manner. Conclusion LPL is expressed by human mesangial ceUs and it has catalytic activity. Expression of LPL in mesangial cells is regulated by VLDL.