P2X4介导高糖刺激肾小管上皮细胞分泌白介素-1β的作用

P2X4 receptor mediates interleukin-1β secretion of renal tubular epithelial cells under high glucose stimulation

目的 探讨P2X4 介导高糖刺激肾小管上皮细胞分泌白介素（IL）-1β 的作用.方法 利用不同浓度（5 -50 mmol/L）葡萄糖刺激肾小管上皮细胞株（HK-2）0 - 72 h,观察细胞上清液中三磷酸腺苷（ATP）和白介素（IL）-1β 的表达.利用细胞外ATP 分解酶（Apyrase）与高糖（35 mmol/L）同时刺激HK-2 细胞48 h,观察细胞上清液IL-1β 的水平.利用小干扰RNA（siRNA）基因沉默HK-2细胞的P2X4 基因,观察高糖对细胞内钾离子钙离子浓度变化和细胞上清液中IL-1β水平的影响.利用PBFI-AM染色剂检测细胞内钾离子,利用Fluo-3/AM检测细胞内钙离子.两组间检测均数的比较采用t 检验.两组以上检测均数的比较进行单因素方差分析.结果 高糖刺激下HK-2 细胞上清液中IL-1β、ATP水平升高呈剂量和时间依赖性.Apyrase 能完全阻断高糖刺激细胞分泌IL-1β（8.2±4.9 μg/L与18.5±4.0 μg/L,P 〈 0.05）.高糖刺激下HK-2 细胞内钾离子浓度降低,钙离子浓度升高.P2X4 基因沉默能够显著阻断高糖刺激下IL-1β 的分泌（12.5±2.9 μg/L与20.3±5.3 μg/L,P 〈 0.05）.结论 P2X4 可介导糖尿病肾病肾小管上皮细胞分泌IL-1β,从而促进肾间质炎症反应.

Objective To investigate the role of P2X4 in interleukin （IL）-1β secretion of renal tubular epithelial cell under high glucose stimulation. Methods Human proximal tubular epithelial cell line （HK-2） cells were grown in media with normal glucose concentration （5 mmol/L）, high glucose concentration （15, 25, 35 and 50 mmol/L）. HK-2 cells were incubated in media with high glucose （35 mol/L, 48 h） with and without apyrase. HK-2 cells were transfected with P2X4 siRNA. Intraeellular K^＋ concentration was measured by PBFI-AM. Cytosolic free Ca^2＋ was indicated by Fluo-3/AM. Data from experiments were analyzed by t-test or ANOVA wherever appropriate, Results The IL- 1β and adenosine triphosphate （ATP） levels of cell supernatants increased in a dose and time dependent manner under high glucose stimulation. Apyrase significantly inhibited IL-1β level elevations caused by high glucose （8.2 ± 4.9 μg/L vs 18.5 ± 4.0 μg/L, P 〈 0.05）. High glucose decreased intracellular K^＋ and increased intracellular Ca^2＋ in HK-2 cell （P 〈 0.05）. The results suggested that high glucose activated P2X receptors of HK-2 cells. Silencing P2X4 with siRNA diminished the high glucose-induced expression of IL-l[3 （12.5 ± 2.9 μg/L vs 20.3 ± 5.3 μg/L, P 〈 0.05）. Conclusion These results demonstrate that the P2X4 mediates the secretion of IL-1D in renal tubular epithelial cells, which may promote the renal interstitial inflammation in diabetic nephropathy