内皮细胞选择性黏附分子在糖尿病肾病中的作用机制

The study on the molecular mechanism of endothelial cells in diabetic nephropathy

目的观察内皮细胞选择性黏附分子(ESAM)在DN中的表达及作用。方法健康野生型C57BL/6小鼠分为ESAM+/+组、ESAM-/-组和STZ组[STZ诱导C57BL/6(ESAM+/+)小鼠],各10只,建立糖尿病小鼠模型。通过免疫组织化学法分析ESAM在肾小球内皮细胞的选择性表达;RT-PCR分析ESAM mRNA在STZ诱导的糖尿病小鼠中的表达;Western blot观察。ESAM蛋白质在糖尿病小鼠肾脏中的表达;电镜分析小鼠肾小球内皮细胞的结构。结果 ESAM-/-组UAlb/Cr高于ESAM+/+组(P<0.05)。STZ组ESAM表达降低(P<0.05),与ESAM+/+组比较,ESAM-/-组肾小球内皮通透性(最大和最小紧密连接比值)降低[(1.69±0.12)vs(1.14±0.04),P<0.05],内皮细胞连接变紧密,且不规则。结论高糖血症降低了ESAM的表达,增加了肾小球内皮的通透性。ESAM能够调控肾小球白蛋白的排泄,在DN中发挥了重要作用。

Objective To investigate the expression and action of endothelial cell selective adhesion molecule（ESAM） in diabetic nephropathy.Methods The diabetic model was established by injection of STZ in wild-type C57 BL / 6 mice.The selective expressions of ESAM in glomerular endothelial cells were analyzed by immunohistochemical.The expressions of ESAM mRNA in the kidney of diabetic mice were analyzed by quantitative real-time PCR.The expressions of ESAM protein in the kidney of diabetic mice were tested using western blot.The structures of glomerular endothelial cells were analyzed by electron microscope.Results Urinary albumin creatinine ratio of ESAM-/- group was significantly higher than that of ESAM＋/＋ group.The Expression of ESAM in diabetic mice significantly reduced.The junctions of endothelial cells were tighter and more irregular in ESAM-/- group than that in ESAM＋/＋ group,with lower glomerular endothelial permeability[the maximum and minimum tight junction ratio：（1.69±0.12） vs（1.14±0.04）,P〈0.05].Conclusion Hyperglycemia may reduce ESAM expression and increase glomerular endothelial permeability.ESAM can regulate glomerular albumin excretion and play an important role in the development of diabetic nephropathy.