球形脂联素抑制高糖环境下肾小管上皮细胞单核趋化蛋白-1的高表达

Global adiponectin suppress the high expression of monocyte chemotactic protein- 1 induced by high glucose in NRK52E cells

目的探讨高糖环境下球形脂联素（globularadiponectin，gAd）对大鼠近端肾小管上皮细胞（NRK．52E）单核趋化蛋白-1（MCP-1）表达的影响以及其与脂联素受体（AdipoR）、p38丝裂原活化蛋白激酶（p38MAPK）的关系。方法体外培养NRK．52E细胞，分为六组：正常对照组（NG，5．6mmol／L葡萄糖）、高糖组（HG，25mmoYL葡萄糖）、gAd处理组1-3（gAd1—3，分别用2mg／L、5mg／L、10mg／LgAd＋25mmol／L葡萄糖）、p38MAPK抑制剂组（SB，10μmol／LSB203580＋25mmol／L葡萄糖）。分别采用RT．PCR和Real．timePCR法检测MCP．1和AdipoRl／AdipoR2的mRNA表达；Western印迹法检测磷酸化p38MAPK（p-p38MAPK）、总p38MAPK（t-p38MAPK）、MCP-1和AdipoRl／Adip0R2的蛋白表达。结果与NG组相比，HG组MCP-1的mRNA和蛋白表达、p-p38MAPK蛋白表达均明显升高（均P〈0．05），t-p38MAPK无明显变化。gad处理组及p38MAPK抑制剂组p-p38MAPK、MCP-1的mRNA和蛋白表达明显降低（均P〈0．05）。AdipoRl及AdipoR2在NG组均有表达，且AdipoR1的mRNA和蛋白表达均明显高于AdipoR2，差异有统计学意义（均P〈0．01）。与NG组比较，HG组及AdipoR2的mRNA和蛋白表达稍低，但差异均无统计学意义（P〉0．05）。与HG组比较，gAD处理组AdipoR1的mRNA和蛋白表达均增加（均P〈0．01），但AdipoR2的mRNA及蛋白表达无改变（P〉0．05）。结论gAd剂量依赖性抑制高糖诱导的大鼠近端肾小管上皮细胞MCP-1的高表达，且这种肾脏保护作用是AdipoR1及p38MAPK介导的。

Objective To investigate the effect of globular adiponectin on the high expression of monocyte chemotactic protein- 1 （MCP- 1） induced by high glucose in rat renal tubular epithelial cells （NRK52E）, and its relationship with adiponectin receptors and p38MAPK. Methods NRK52E cells were cultured in vitro and divided into six groups： normal glucose group （NG, 5.6 mmol/L glucose）, high glucose group（HG, 25 mmol/L glucose）, gAd groupl （HG＋gAd 2 mg/L）, gAd group2 （HG＋gAd 5 mg/L）, gad group3 （HG＋gAd 10 mg/L）, p38MAPK antagonist group： （SB, HG＋SB203580 10 μmol/L）. The protein expression of phosphorylated p38MAPK （p- p38MAPK）, total p38MAPK （t- p38MAPK）, MCP- 1 and AdipoRl/AdipoR2 were examined by western blotting. The mRNA expression of MCP- 1 and AdipoR1/AdipoR2 were detected by RT- PCR and realtime PCR respectively. Results Compared with NG group, the mRNA and protein expression of MCP- 1 increased significantly in HG group （all P 〈 0.05）. The phosphorylation of p38MAPK increased （P 〈 0.05） with no change int-p38MAPK protein. The addition of gAd or SB203580 inhibited the unregulation of MCP-1 and p- p38MAPK induced by HG. Two kinds of adipoR, adipoR1 and adipoR2, were all detectable in NG group, and mRNA and protein expression of adipoR1 was higher than that of adipoR2 （P 〈 0.01）. Compared with NG group, the expression of adipoR decreased in HG group, but the difference had no statistical significance（P 〉 0.05）. Compared to HG group, the mRNA and protein expression of adipoR1 increased in gAd groups （all P 〈 0.01）. Conclusion The gAd can dose-dependently attenuate the overexpression of MCP- 1 induced by high glucose, and this protective effect may be mediated by adipoR1 and p38MAPK.