氧化低密度脂蛋白通过血凝素样氧化低密度脂蛋白受体1诱导血管内皮细胞粘附分子的表达

目的探讨血凝素样氧化低密度脂蛋白受体1（LOX-1）在氧化低密度脂蛋白（ox—LDL）诱导血管内皮细胞粘附分子表达中的作用。方法用不同浓度ox-LDL培养人脐静脉内皮细胞（HUVECs）,用RrealtimeRT—PCR测定LOX-1 mRNA的表达;RT—PCR测定细胞间粘附分子1（ICAM-1）、血管细胞粘附分子1（VCAM-1）以及E选择素的mRNA表达;用Westernblot测定LOX-1、ICAM-1、VCAM-1以及E选择素蛋白的表达,观察ox-LDL对血管内皮细胞粘附分子表达的影响。HUVECs预先用聚肌苷酸[poly（I）]和爱兰苔胶处理,再用ox—LDL培养,再分别测定上述粘附分子的表达水平,比较加入LOX-1阻断剂前后粘附分子表达的变化。结果ox-LDL各剂量组皆可上调LOX-1、ICAM-1、E选择素的mRNA和蛋白表达（P〈0．01）,在10～50μm/ml剂量范围内呈现明显的剂量一效应关系（P〈0．01）,但ox—LDL对VCAM-1的表达没影响。HUVECs预先与250μg／ml的poly（Ⅰ）或爱兰苔胶作用2h,然后加入50μg/ml的ox—LDL作用24h。poly（Ⅰ）和爱兰苔胶都能抑制ox—LDL诱导的LOX-1、ICAM-1和E选择素的mRNA和蛋白表达水平,与未阻断组相比,差异皆有统计学意义（P〈0．01）。结论ox—LDL可以上调血管内皮细胞粘附分子的表达,LOX-1受体阻断剂可以部分阻断ox—LDL的上调作用,ox-LDL诱导血管内皮细胞粘附分子的表过是通过LOX-1介导的。

Effects of LOX-1 on expression of adhesion molecules induced by ox-LDL in HUVECs

OBJECTIVE: To investigate the effects of oxidized low-density lipoprotein receptor 1 (LOX-1) on secretion of adhesive molecules mediated by ox-LDL in human umbilical endothelial cells (HUVECs). METHODS: HUVECs with different concentration of ox-LDL (0, 10, 20, 50, 100 microg/ml) were incubated for 24 h, or HUVECs were pretreated with 250 microg/ml poly (I) or 250 microg/ml carrageenan for 2 h and then incubated with 50 microg/ml ox-LDL for another 24 h. Expression of LOX-1 was determined by realtime RT-PCR and Western blot. mRNA and protein of ICAM-1, VCAM-1 and E-selectin were examined by RT-PCR and Western blot respectively. RESULTS: Incubation of HUVECs with ox-LDL (10-100 microg/ml) enhanced the expressions of LOX-1, ICAM-1 and E-selectin in a concentration-dependent manner (P < 0.01). On the contrary, ox-LDL did not affect the expression of VCAM-1 by HUVECs. The expression of LOX-1, ICAM-1 and E-selectin induced by ox-LDL were reduced in HUVECs pretreated with 250 microg/ml poly (I) or 250 microg/ml carrageenan for 2 h and then incubated with 50 microg/ml ox-LDL for 24 h. This showed that both poly (I) and carrageenan obviously decreased the expression of LOX-1, ICAM-1 and E-selectin induced by ox-LDL. CONCLUSION: ox-LDL may upregulate the expression of LOX-1, ICAM-1 and E-selectin, and LOX-1 blocker may partly inhibit this upregulation. The results suggest that the expression of inflammatory molecules induced by ox-LDL in HUVECs is mediated by LOX-1.