氧化LDL对人脐静脉内皮细胞Connexin37表达的影响

目的研究氧化低密度脂蛋白（Ox—LDL）对体外培养的人脐静脉内皮细胞缝隙连接蛋白Connexin37基因表达的影响。方法常规人脐静脉内皮细胞体外培养并传代。根据Ox—LDL的不同浓度分为对照组（不加Ox—LDL）及50、100、200mg／L干预组，干预24h后通过RT-PCR方法检测并比较各组内皮细胞Connexin37mRNA的表达。根据Ox—LDL干预的不同时间分为对照组（不加Ox—LDL）以及50mg／LOx—LDL干预6、12、24、48、72h组，检测比较各组Connexin37mRNA的表达情况；并检测比较对照组和100mg／L Ox-LDL干预组间Connexin37蛋白的表达水平。结果50、100、200mg／L的Ox—LDL干预24h后均能引起内皮细胞Connexin37mRNA表达的显著减少（P〈0.01），以50mg／L的Ox—LDL干预效果最明显（P〈0.01）.50mg／L的Ox-LDL干预12h后Connexin37mRNA的表达开始显著下降（P〈0．01），24h下降最明显（P〈0．01），48h仍下降（P〈0．05），至72h时恢复到刺激前水平。100mg／L的Ox—LDL干预24h后内皮细胞Connexin37蛋白表达水平显著降低（P〈0.01）。结论Ox-LDL可以抑制人脐静脉内皮细胞Connexin37mRNA和Connexin37蛋白的表达。

Effect of oxidized LDL on expression of connexin37 gene in cultured human umbilical vein endothelium cells

Objective To investigate the effect of oxidized LDL （Ox-LDL） on the expression of gap junction protein connexin37 gene in cultured human umbilical vein endothelium cell s （HUVEC）. Methods Human umbilical vein endothelial cell cultured in normal condition were treated with 0mg/L, 50mg/L,100mg/L and 200mg/L Ox-LDL respectively for 24 h; then the expression of connexin37 gene mRNA in HUVEC was detected by RT-PCR method. The cultured HUVECs were treated with 50mg/L Ox-LDL for 0h,6h, 12h, 24h, 48h and 72h respectively; then the expression of connexin37 mRNA was detected. The expression of connexin 37protein level was also detected by immunocytochemistry in 0mg/L and 100mg/L Ox-LDL groups. Results Ox-LDL at concentration of 50mg/L, 100mg/L and 200mg/L down-regulated mRNA expression level of Connexin37 gene in cultured HUVEC after 24 h intervention （P 〈0.01）,while the 50mg/L Ox-LDL was most predominant. After 12 h intervention with 50mg/L Ox-LDL the mRNA expression level began to decrease （P〈0.01）, reached the lowest level at 24 h （P〈0.01） and maintained for 48 h （P 〈0.05）, then the mRNA expression recovered after 72 h intervention （P 〉0.05）. After 24h treatment with 100 mg/L Ox-LDL the connexin37 .protein expression in HUVECs was decreased compared to the control group （P 〈0.01）. Conclusion Ox-LDL can down-regulate the protein and mRNA expression of Connexin37 gene in cultured human vein endothelium cells,which indicates that connexin37 may be involved in pro-atherosclerotic effect of Ox-LDL.