Podocyte-specific overexpression of metallothionein mitigates diabetic complications in the glomerular filtration barrier and glomerular histoarchitecture: a transmission electron microscopy stereometric analysis
Podocyte-specific overexpression of metallothionein mitigates diabetic complications in the glomerular filtration barrier and glomerular histoarchitecture: a transmission electron microscopy stereometric analysis
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DOI：
10.1002/dmrr.2342
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发表时间：
2013-02-01
影响因子：
8
通讯作者：
Epstein, Paul N.
中科院分区：
文献类型：
--
作者：
Carlson, Edward C.;Chhoun, Jennifer M.;Epstein, Paul N.
背景我们以前证明了肾小球内血氨屏障的细胞和细胞外成分对OVE转基因小鼠的损伤敏感，OVE转基因小鼠是一种有价值的表达大量蛋白尿的人类糖尿病肾病模型。方法为了验证我们的假设，即肾小球滤过屏障损伤OVE小鼠可能是氧化损伤足细胞的结果，150日龄的双转基因OVENmt糖尿病小鼠，过表达抗氧化剂金属硫蛋白特异性足细胞进行了检查，通过酶联免疫吸附试验减轻白蛋白尿和无偏透射电子显微镜（TEM）立体测量保护从慢性结构性糖尿病并发症。结果OVE和OVENmt小鼠血糖和HbA1c水平无明显差异，但OVENmt小鼠尿蛋白明显减少（平均>7倍）。有趣的是，Nmt转基因提供了显着的肾小球保护，对糖尿病肾病并发症以外的足细胞。OVENmt小鼠的肾小球滤过屏障损伤减少，包括内皮管腔开窗占据的面积显著增加（13%），肾小球基底膜（GBM）增厚显著减少（17%）和足细胞消失显著减少（18%）。此外，OVENmt小鼠的肾小球体积显着减少（50%）、肾小球内皮细胞减少（33%）、系膜细胞减少（57%）和总肾小球细胞减少（40%）。结论足细胞的氧化损伤可导致糖尿病肾病的主要特征，包括严重和持续的蛋白尿、特异性肾小球滤过屏障损伤以及肾小球内皮细胞和系膜细胞数量的改变。重要的是，这些糖尿病并发症显着减轻足细胞靶向金属硫蛋白过表达。版权所有（c）2012约翰威利父子有限公司
Background We previously demonstrated that cellular and extracellular components of the bloodurine barrier in renal glomeruli are susceptible to damage in OVE transgenic mice, a valuable model of human diabetic nephropathy that expresses profound albuminuria. Methods To test our hypothesis that glomerular filtration barrier damage in OVE mice may be the result of oxidative insult to podocytes, 150-day-old bi-transgenic OVENmt diabetic mice that overexpress the antioxidant metallothionein specifically in podocytes were examined by enzyme-linked immunosorbent assay for albuminuria mitigation and by unbiased transmission electron microscopy (TEM) stereometry for protection from chronic structural diabetic complications. Results Although blood glucose and HbA1c levels were indistinguishable in OVE and OVENmt animals, albuminuria was significantly reduced (average >7-fold) in OVENmt mice through 8months of age. Interestingly, the Nmt transgene provided significant glomerular protection against diabetic nephropathic complications outside of the podocyte. Glomerular filtration barrier damage was reduced in OVENmt mice, including significantly increased area occupied by endothelial luminal fenestrations ( 13%), significantly reduced glomerular basement membrane (GBM) thickening ( 17%) and significantly less podocyte effacement ( 18%). In addition, OVENmt mice exhibited significantly reduced glomerular volume ( 50%), fewer glomerular endothelial cells ( 33%), fewer mesangial cells ( 57%) and fewer total glomerular cells ( 40%). Conclusions These results provide evidence of oxidative damage to podocytes induces primary diabetic nephropathic features including severe and sustained albuminuria, specific glomerular filtration barrier damage and alterations in glomerular endothelial and mesangial cell number. Importantly, these diabetic complications are significantly mitigated by podocyte targeted metallothionein overexpression. Copyright (c) 2012 John Wiley & Sons, Ltd.