Department of Nephrology, University hospital Regensburg, Regensburg, Germany.
Kompetenzzentrum Fluoreszente Bioanalytik (KFB), Regensburg, Germany.
Nephrol Dial Transplant. 2018 Sep 1;33(9):1533-1544. doi: 10.1093/ndt/gfx359.
Although diabetic nephropathy (DN) is the most common cause for end-stage renal disease in western societies, its pathogenesis still remains largely unclear. A different gene pattern of diabetic and healthy kidney cells is one of the probable explanations. Numerous signalling pathways have emerged as important pathophysiological mechanisms for diabetes-induced renal injury.
Glomerular cells, as podocytes or mesangial cells, are predominantly involved in the development of diabetic renal lesions. While many gene assays concerning DN are performed with whole kidney or renal cortex tissue, we isolated glomeruli from black and tan, brachyuric (BTBR) obese/obese (ob/ob) and wildtype mice at four different timepoints (4, 8, 16 and 24 weeks) and performed an mRNA microarray to identify differentially expressed genes (DEGs). In contrast to many other diabetic mouse models, these homozygous ob/ob leptin-deficient mice develop not only a severe type 2 diabetes, but also diabetic kidney injury with all the clinical and especially histologic features defining human DN. By functional enrichment analysis we were able to investigate biological processes and pathways enriched by the DEGs at different disease stages. Altered expression of nine randomly selected genes was confirmed by quantitative polymerase chain reaction from glomerular RNA.
Ob/ob type 2 diabetic mice showed up- and downregulation of genes primarily involved in metabolic processes and pathways, including glucose, lipid, fatty acid, retinol and amino acid metabolism. Members of the CYP4A and ApoB family were found among the top abundant genes. But more interestingly, altered gene loci showed enrichment for processes and pathways linked to angioneogenesis, complement cascades, semaphorin pathways, oxidation and reduction processes and renin secretion.
The gene profile of BTBR ob/ob type 2 diabetic mice we conducted in this study can help to identify new key players in molecular pathogenesis of diabetic kidney injury.
虽然糖尿病肾病（DN）是西方社会终末期肾病的最常见原因，但其发病机制仍很大程度上不清楚。糖尿病和健康肾脏细胞的不同基因模式是其中一个可能的解释。许多信号通路已成为糖尿病引起的肾损伤的重要病理生理机制。
肾小球细胞，如足细胞或系膜细胞，主要参与糖尿病肾脏病变的发展。虽然许多关于 DN 的基因检测都是在整个肾脏或肾皮质组织中进行的，但我们从黑棕杂色、短胖（BTBR）肥胖/肥胖（ob/ob）和野生型小鼠的肾小球中分离出来，并在四个不同时间点（4、8、16 和 24 周）进行了 mRNA 微阵列分析，以鉴定差异表达基因（DEGs）。与许多其他糖尿病小鼠模型不同，这些纯合子 ob/ob 瘦素缺乏小鼠不仅会发展出严重的 2 型糖尿病，而且还会出现糖尿病肾病损伤，具有所有定义人类 DN 的临床和特别是组织学特征。通过功能富集分析，我们能够研究不同疾病阶段 DEGs 富集的生物学过程和途径。通过定量聚合酶链反应从肾小球 RNA 中验证了随机选择的 9 个基因的表达变化。
ob/ob 型 2 型糖尿病小鼠的基因表达上调和下调主要涉及代谢过程和途径，包括葡萄糖、脂质、脂肪酸、视黄醇和氨基酸代谢。CYP4A 和 ApoB 家族的成员被发现是最丰富的基因之一。但更有趣的是，改变的基因座富集了与血管生成、补体级联、神经鞘氨醇途径、氧化还原过程和肾素分泌相关的过程和途径。
我们在这项研究中对 BTBR ob/ob 型 2 型糖尿病小鼠进行的基因谱分析有助于鉴定糖尿病肾病损伤分子发病机制中的新关键因素。
