【作者】 屈伸； 李映红； 田俊； 王燕； 宗义强； 冯友梅； 冯宗忱； 邓耀祖；

【机构】 华中科技大学同济医学院生物化学与分子生物学系；

【摘要】 为了研究极低密度脂蛋白受体(very low density lipoprotein receptor,VLDL-R)的主要天然配体VLDL、β-VLDL对巨噬细胞VLDL-R表达调控效应及其信号转导途径,以VLDL、β-VLDL温育小鼠巨噬细胞RAW264.7,检测胞内VLDL—R mRNA的表达变化;构建含VLDL-R5’端转录调控序列的重组质粒pGL4.2VR-luciferase,转染RAW264.7细胞后,检测VLDL、β-VLDL温育对VLDL-R5’端转录调控序列转录活性的影响;采用Western Blot方法检测细胞温育后ERK1/2活性变化;应用各种信号转导途径抑制剂的阻断效应,确定VLDL—R表达调控的信号转导途径。实验结果显示:VLDL、β-VLDL通过PKC-ERK1/2信号转导途径,转录激活VLDL-R表达。更多还原

【Abstract】 Very low density lipoprotein receptor (VLDL - R) is thought to participate in the pathogen-esis of atherosclerosis induced by VLDL and β - VLDL The present study was undertaken to elucidate the effects of VLDL andβ - VLDL on VLDL - R expression and its signaling pathway. The study on murine macro phages incubated with VLDL orβ - VLDL showed that both of them increased VLDL - R expression, which was observed at levels of VLDL - R mRNA by RT - PCR analysis and transcriptional regulation of VLDL - R gene promoter - driven luciferase activity. Using Western Blot Assay to detect phosphorylated ERK1/2 protein, we found that VLDL andβ - VLDL stimulated ERK1/2 activity in a PKC - dependent manner. Studies using different protein kinases inhibitors or activators indicated that the effect of VLDL orβ - VLDL - induced VLDL - R expression in macrophages was extremely abolished by an inhibitor of ERK and an inhibitor of PKC. Taken together, our findings reveal that VLDL - orβ - VLDL - induced VLDL - R expression via PKC/ERK1/2 cascades and the effect is linked to transcriptional activation of VLDL - R gene promoter.更多还原