脂联素对高糖环境下肾小管上皮细胞凋亡及纤维化的影响

Effects of Adiponectin on Cell Apoptosis and Fibrosis in Human Renal Tubular Epithelial Cell Cultured with High Glucose

目的动态观察人肾小管上皮细胞在高糖环境下转化生长因子(TGF)-β1及下游正负反馈调节因子smad-3、smad-7、BMP-7的表达水平及加入脂联素干预后的影响,探讨脂联素对高糖环境下人近曲肾小管上皮细胞株(HK-2)的凋亡及纤维化的影响,以揭示脂联素(ADPN)对糖尿病肾病可能的保护机制。方法体外培养人肾小管上皮细胞(HK-2)随机分为:①正常对照组(D-葡萄糖浓度5.5mmol/L);②高糖组(D-葡萄糖浓度30.0mmol/L);③高糖+脂联素组(D-葡萄糖浓度30.0mmol/L+ADPN浓度2.5μg/ml),分别于24、48、72h,测定各时间段细胞的凋亡率及TGF-β1、BMP-7和smad-3、smad-7mRNA的表达变化。结果与对照组相比较,随着高糖的持续作用细胞凋亡率增加;高血糖导致促纤维化细胞因子TGF-β1、smad3表达增加,过度激活TGF-β1/smad信号转导通路,加入脂联素干预后,信号转导抑制因子BMP-7、smad-7的表达增加,与高糖组相比,差异有统计学意义(P<0.05)。结论脂联素可通过提高BMP-7、smad-7的表达,降低TGF-β1、smad-3的表达以阻断TGF-β1/smad信号转导通路的过度激活,调控TGF-β1/smad信号转导通路的平衡,达到保护肾脏的作用。

Objective To study the dynamic changes of expression of transformation growth factor （TGF） - β1 and downstream positive and negative feedback adjustment factor smad - 3, smad - 7, BMP - 7 in human renal tubular epithelial cell cultured with high glucoses and the effect after join adiponectin intervention,then to discuss the effects of adiponectin on cell apoptosis and fibrosis in human renal tubular epithelial cell cultured with high glucose,in order to reveal the possible protective mechanism of adiponectin on DN. Methods The cells are divided into three groups randomly： ①normal group（5.5mmol/L D -glucose） ;②the high glucose group （30.0mmol/ L glucose） ;③the high glucose ＋ ADPN group （30. Ommol/L glucose ＋ 2.5μg/ml adiponectin）. These cells were cultured 24, 48, 72h re- spectively. The apoptosis rate of the Hk - 2 was tested by the flow cytometry. The expressions of smad - 3mRNA and smad - 7mRNA were assayed with reverse transcription polymerase chain reaction （RT- PCR）. The expressions of TGF -β1 and BMP- 7 were measured by enzyme - linked immuno sorbent assay （ELISA）. Results Compared with the noamal group, the sustaining effects of high glucose increased the apoptosis rate. Hyperglycemia increased the expression of promote fibrosis cell factor TGF - β1, smad - 3, than led to exces- sive activation the signaling pathways of TGF - β1/smad. After adiponectin intervention, the expression of inhibited factor - BMP - 7, smad - 7 upregulated. The difference between the high glucose group and the adiponectin group was statistically significant （P 〈 0.05 ）. Conclusion Adiponectin can inhibit the excessive activation of TGF - β1/smad signaling pathways through promoting the expression of BMP -7, smad -7 and reducing the expression of TGF - β1, smad -3, and making it balance, which provides a new method to prevention and cure DN.