高糖及胰岛素对肾小管上皮细胞间隙连接蛋白43表达的影响

High glucose and insulin enhance expression of connexin43 in cultured human renal tubular epithelial cells

目的观察高糖及胰岛素对肾小管上皮细胞间隙连接蛋白43(connexin43)表达的影响。方法用高糖及胰岛素刺激肾小管上皮细胞,检测不同分组中connexin43蛋白的表达。用免疫荧光分析connexin43蛋白的表达;用RT-PCR检测connexin43 mRNA的表达。结果高糖及胰岛素各自单独作用可以使肾小管上皮细胞connexin43的表达有所减少,而高糖刺激肾小管上皮细胞后,加入一定剂量胰岛素干预,connexin43的表达较单纯高糖组有所增加。结论高糖及一定剂量胰岛素均对肾小管上皮细胞connexin43蛋白的表达具有影响,一定剂量胰岛素对高糖刺激的肾小管上皮细胞间隙连接的损伤具有积极作用。

Objective To observe the expression of gap junction protein, connexin43 in cultured human renal tubular epithelial cells （HKCs） after the treatment with high glucose and insulin. Methods The normal HKCs were divided into 6 groups, that is, normal control group （5.5 mmol/L）, high glucose group （30 mmol/L）, insulin group （10^-9 mmol/L） , high insulin group （insulin 10^-7 mmol/L） , high glucose plus insulin group （glucose 30 mmol/L ＋ insulin 10^-9 mmol/L） and high glucose plus high insulin group （glucose 30 mmol/L ＋ insulin 10^-7 mmoL/L）, the expression of connexin43 protein in HKCs of different groups was detected by Immunofluo- rescence microscopy and RT-PCR at protein and mRNA levels. Results Single insulin （10^-7 mmol/L, but not 10^-9 mmol/L） or high glucose （5.5 mmol/L） significantly down-regulated the connexin43 expression in HKCs （P 〈0.05）. However, When these two stimulus combined together, the expressions of eonnexin43 at rnRNA and protein levels were obvious enhanced than those of normal control group. And the high glucose plus high insulin group had markedly increased expression in comparison to those of high glucose group. Conclusion Both insulin at certain dose and high glucose influence the expression of gap junction protein in HKCs. However, high-dose insulin can attenuate the impairment of gap junction resulting from the stimulation of high glucose.