高糖通过ERK1/2通路对人肾小管上皮细胞脂联素表达的影响

Effect of high glucose on expression of adiponectin through ERK1/2 signaling pathway in HK-2 cells

目的通过体外培养人肾小管上皮细胞(human proximal tubular epithelial cells,HK-2),观察高糖对HK-2脂联素(adiponectin,ADPN)表达水平的影响并探讨其可能机制。方法将培养的HK-2细胞分为4组:①低糖对照组(5.6 mmol/L葡萄糖);②PD98059(职K1/2信号传导通路的抑制剂)组(5.6 mmol/L葡萄糖+50μmol/L PD98059);③高糖组(30 mmol/L葡萄糖);④高糖+PD98059组(30 mmol/L葡萄糖+50μmol/L PD98059)。各组分别培养48 h后荧光定量聚合酶链式反应(polymerase chain reaction,PCR)检测HK-2细胞过氧化物酶体增殖物激活受体γ(peroxisome proliferator activator receptor,PPAR-γ)及脂联素mRNA的表达,免疫印迹(Western blotting)法检测各组脂联素蛋白的表达水平。结果 HK-2细胞表达脂联素;PD98059组与低糖对照组相比,PPAR-γmRNA及脂联素的mRNA和蛋白表达的差异均无统计学意义(均P>0.05);与低糖对照组相比,高糖组PPAR-γmRNA及脂联素mRNA和蛋白表达均显著降低,差异均有统计学意义(均P<0.05);与高糖组相比,高糖+PD98059组PPAR-γmRNA及脂联素mRNA和蛋白表达均显著升高,差异均有统计学意义(均P<0.05)。结论高糖可以降低HK-2细胞脂联素mRNA和蛋白的表达;高糖作用于HK-2细胞可能是通过激活ERK1/2信号传导通路降低PPAR-γ的表达,从而影响其脂联素的表达。

Objective Adiponectin is closely related to the development of diabetic kidney disease. Recent evidence suggests that human proximal tubular epithelial cells could express and secrete adiponectin and the expression of adiponectin could be inhibited by high glucose. However, the precise mechanisms remain poorly understood. We aim to observe the effect of high glucose on the expression of adiponectin and to explore its possible mechanism in human proximal tubular epithelial ceils in vitro. Methods Human proximal tubular epithelial ceils were cultivated in four groups for 48 h.. normal glucose group （NG, 5. 6 mmol/L D-glucose）; PD98059 group （PD, 5. 6 mmol/L D-glucose with 50 μmol/L PD98059）; high glucose group （HG, 30 mmol/L D-glucose）; high glucose with PD98059 group （HG＋ PD, 30 mmol/L D-glucose with 50 μmmol/L PD98059）. The rnRNA expression of peroxisome proliferator activator receptor （PPAR）-γ and adiponectin was detected by real-time polymerase chain reaction （PCR） and the protein level of adiponectin by Western blotting. Results HK-2 ceils expressed adiponectin. As compared with normal glucose group, There was no significant difference in the expression level of PPAR-γ and adiponectin mRNA and adiponectin protein between normal glucose group and PD98059 group （P〈0. 05）, but the expression level of PPAR-γ, and adiponectin mRNA and adiponectin protein decreased significantly in high glucose group as compared with normal glu-cose group （P〈0. 05）. As compared with high glucose group, the expression of PPAR-γ and adiponectin mRNA and adiponectin protein increased significantly in high glucose with PD98059 group （P〈 0. 05）. Conclusions HK-2 cells expressed adiponectin. The high glucose may reduce the expression of PPAR-γ, mRNA through the ERK1/2 signaling pathway, thus reducing the expression of adiponectin in HK-2 cells.