糖基化终末产物损伤冠状动脉平滑肌细胞K_v通道

Advanced glycation end products impair voltage-gated K^+ channels in coronary vascular smooth muscle cells

目的研究糖基化终末产物(advanced glycation end products,AGEs)对大鼠冠状动脉平滑肌细胞电压门控性钾离子(voltage-gated K^+,K_v)通道电流的影响。方法分离大鼠冠状动脉平滑肌细胞,分为空白对照组、糖基化牛血清白蛋白(AGEbull serum albumin,AGE-BSA)组、AGE-BSA+抗AGE受体抗体(anti-receptor of AGEs immunoglobulin G,anti-RAGE Ig G)组进行干预。采用膜片钳技术检测各组细胞K_v通道电流,采用Western blotting、实时荧光定量PCR方法检测各组细胞K_v1.2和K_v1.5通道蛋白及mRNA的表达。结果 AGE-BSA直接干预冠状动脉平滑肌细胞明显抑制了平滑肌细胞的K_v电流达32.7%,并使K_v1.2和K_v1.5通道蛋白及mRNA的表达明显下调。而给予anti-RAGE Ig G预处理30 min后再加入AGE-BSA刺激,平滑肌细胞的K_v电流密度及K_v1.2和K_v1.5通道蛋白及mRNA的表达与空白对照组相比,差异无统计学意义。结论 AGEs通过结合RAGE损伤冠状动脉平滑肌细胞K_v通道。

Objective To investigate the role of advanced glycation end products（ AGEs） in impairment of voltage-gated K＋（ Kv）channels in rat coronary vascular smooth muscle cells（ VSMCs）. Methods We isolated rat coronary VSMCs. The cells were incubated either in control medium,or medium with 100 μg/m L AGE-bovine serum albumin（ AGE-BSA）,or medium with 100 μg/m L AGE-BSA plus 100 μg/m L anti-receptor of AGEs immunoglobulin G（ anti-RAGE Ig G）. Patch-clamp recording was used to assess the Kvcurrents.Western blotting and quantitative real-time PCR techniques were used to assess protein and mRNA expression of Kv1. 2 and Kv1. 5.Results Incubation of VSMCs with AGE-BSA reduced Kvcurrent density by 32. 7% and decreased both protein and mRNA expression of Kv1. 2 and Kv1. 5 channels,whereas blocking AGE-BSA interacting with their receptors by preincubation with anti-RAGE Ig G for 30 minutes prevented AGE-BSA-induced impairment of Kvchannels. Conclusion AGEs impair Kvchannels in coronary VSMCs by interacting with RAGE.