LOX-1在D-葡萄糖诱导人肾小球系膜细胞表达TGF-β1中的作用

ROLE OF LOX-1 IN D-GLUCOSE INDUCED EXPRESSION OF TRANSFORMING GROWTH FACTOR-β1 IN HUMAN GLOMERULAR MESANGIAL CELL

目的探讨血凝素样氧化低密度脂蛋白受体1(LOX-1)在D-葡萄糖诱导人肾小球系膜细胞表达转化生长因子β1(TGF-β1)中的作用。方法在体外培养人肾小球系膜细胞,在不同时间加入不同浓度的D-葡萄及LOX-1特异性阻滞剂JTX92,用半定量RT-PCR法检测LOX-1和TGF-β1基因表达的相对含量,用Western blot法检测p38 MAPK蛋白质的相对含量,用酶联免疫吸附法(ELISA)检测细胞培养液中TGF-β1浓度。结果D-葡萄糖以时间和浓度依赖的方式增加细胞内LOX-1和TGF-β1 mRNA表达和培养液中TGF-β1浓度,同时也以时间和浓度依赖的方式增加p38 MAPK的表达,JTX92可以明显抑制LOX-1、TGF-β1和p38 MAPK的表达。结论高浓度D-葡萄糖可能通过上调LOX-1的表达,激活细胞内的p38 MAPK信号传递途径,促使人肾小球系膜细胞合成并分泌大量TGF-β1,参与糖尿病肾病的发生发展。

Objective To study the role of lectin-like oxidized low-density lipoprotein receptor-1（LOX-1） in the expression of transforming growth factor-β1（TGF-β1） induced by D-Glucose in human glomerular mesangial cells.MethodsHuman glomerular mesangial cells were incubated with D-Glucose（100 to 600mg/dl） for 6 to 48 hour and pretreated with JTX92（10ug/ml）,a blocking antibody to LOX-1,before exposure to D-Glucose.The expression of LOX-1 and TGF-β1 mRNA was determined by reverse transcriptase polymerase chain reaction.Western blot was used to detect the activity of p38MAPK.The level of TGF-β1 protein was measured by enzyme-linked immunosorbent assay.ResultsD-Glucose increased the expression of TGF-β1mRNA and protein、LOX-1 mRNA and p38MAPK activity in a concentration-and time-dependent manner,which was inhibited by JTX92.The effect of D-Glucose was mediated by the scavenger receptor LOX-1,because pretreatment of HGMC with JTX92 prevented the expression of TGF-β1、LOX-1 and p38MAPK in response to D-Glucose（P〈 0.01）.ConclusionD-glucose can increase the expression of TGF-β1 mRNA and the synthesis and secretion of TGF-β1 protein by upregulating LOX-1 and activating p38MAPK signal pathway in human glomerular mesangial cells.