Shin Jae Il, Park Hye-Young, Park Se Jin, Ha Tae-Sun
Department of Pediatrics, Yonsei University College of Medicine, Severance Children's Hospital, Seoul, Korea.
Iran J Kidney Dis. 2015 May;9(3):194-201.
This study aimed to investigate the effect of vitamin D on the pathologic changes of podocyte β-catenin and P-cadherin and podocyte permeability induced by diabetic conditions.
We cultured mouse podocytes under normal glucose (5 mM, control); high glucose (HG, 30 mM); advanced glycosylation end products (AGE)-added; and HG plus AGE-added conditions and treated with vitamin D. The distribution of podocyte β-catenin and P-cadherin was shown by confocal microscopy, and protein levels of β-catenin and P-cadherin by Western blotting. Podocytes were incubated with vitamin D at the concentrations of 10 nM and 50 nM for 6, 24, and 48 hours.
The dextran filtration through monolayered podocytes tended to increase in AGE and HG condition compared to that in B5 at 16 hours in permeability assay, which was improved by vitamin D. In confocal imaging, the distribution of β-catenin and P-cadherin were internally concentrated by diabetic conditions, which was ameliorated by vitamin D. In Western blotting, HG and AGE decreased β-catenin protein levels at 6, 24, and 48 hours and vitamin D improved the decreased β-catenin protein levels at 6, 24, and 48 hours. Advanced glycosylation end products also decreased P-cadherin protein amount by 22.9% and 59.1% (P <.01) at 24 hours, respectively, which was improved by vitamin D.
Our results suggest that HG and AGE have an influence on the redistribution of β-catenin and P-cadherin and amount of β-catenin protein of podocytes, thereby causing hyperpermeability, which can be reversed by vitamin D.
本研究旨在探讨维生素D对糖尿病状态下足细胞β-连环蛋白和P-钙黏蛋白的病理变化以及足细胞通透性的影响。
我们在正常葡萄糖（5 mM，对照组）、高糖（HG，30 mM）、添加晚期糖基化终产物（AGE）以及添加HG加AGE的条件下培养小鼠足细胞，并给予维生素D处理。通过共聚焦显微镜观察足细胞β-连环蛋白和P-钙黏蛋白的分布，采用蛋白质免疫印迹法检测β-连环蛋白和P-钙黏蛋白的蛋白质水平。将足细胞分别用浓度为10 nM和50 nM的维生素D孵育6小时、24小时和48小时。
在通透性测定中，与B5组相比，在16小时时，AGE和HG条件下单层足细胞对葡聚糖的滤过率有增加趋势，而维生素D可改善这种情况。在共聚焦成像中，糖尿病状态使β-连环蛋白和P-钙黏蛋白的分布向内集中，而维生素D可改善这种情况。在蛋白质免疫印迹法中，HG和AGE在6小时、24小时和48小时降低了β-连环蛋白的蛋白质水平，而维生素D改善了6小时、24小时和48小时降低的β-连环蛋白蛋白质水平。晚期糖基化终产物在24小时时也分别使P-钙黏蛋白的蛋白量降低了22.9%和59.1%（P<.01），而维生素D可改善这种情况。
我们的结果表明，HG和AGE对足细胞β-连环蛋白和P-钙黏蛋白的重新分布以及β-连环蛋白的蛋白量有影响，从而导致高通透性，而维生素D可使其逆转。
