Brunskill Eric W, Potter S Steven
Cincinnati Children's Medical Center, 3333 Burnet Ave., Cincinnati, OH, 45229, USA.
BMC Nephrol. 2015 May 13;16:71. doi: 10.1186/s12882-015-0063-z.
Mutations in several genes expressed in podocytes, including Cd2ap, have been associated with focal segmental glomerulosclerosis in humans. Mutant mouse models provide an opportunity to better understand the molecular pathology that drives these diseases.
In this report we use a battery of transgenic-GFP mice to facilitate the purification of all three major cell types of the glomerulus from Cd2ap mutant mice. Both microarrays and RNA-seq were used to characterize the gene expression profiles of the podocytes, mesangial cells and endothelial cells, providing a global dual platform cross-validating dataset.
The mesangial cells showed increased expression of profibrotic factors, including thrombospondin, Tgfb2 and Tgfb3, as well as the angiogenesis factor Vegf. They also showed upregulation of protective genes, including Aldh1a2, involved in retinoic acid synthesis and Decorin, a Tgfb antagonist. Of interest, the mesangial cells also showed significant expression of Wt1, which has generally been considered podocyte specific. The Cd2ap mutant podocytes showed upregulation of proteases as well as genes involved in muscle and vasculature development and showed a very strong gene expression signature indicating programmed cell death. Endothelial cells showed increased expression of the leukocyte adhesion associated factors Vcam1 and Sele, as well as Midkine (promoting angiogenesis), endothelin and many genes responsive to cytokines and interferons.
This study provides a comprehensive analysis of the changing properties of the three cell types of the glomerulus in Cd2ap mutants, identifying activated and repressed pathways and responsible genes, thereby delivering a deeper molecular understanding of this genetic disease.
足细胞中表达的几种基因发生突变，包括Cd2ap，已与人类局灶节段性肾小球硬化相关。突变小鼠模型为更好地理解驱动这些疾病的分子病理学提供了机会。
在本报告中，我们使用一系列转基因绿色荧光蛋白（GFP）小鼠，以促进从Cd2ap突变小鼠中纯化肾小球的所有三种主要细胞类型。微阵列和RNA测序均用于表征足细胞、系膜细胞和内皮细胞的基因表达谱，提供一个全面的双平台交叉验证数据集。
系膜细胞显示促纤维化因子表达增加，包括血小板反应蛋白、转化生长因子β2（Tgfb2）和转化生长因子β3（Tgfb3），以及血管生成因子血管内皮生长因子（Vegf）。它们还显示出保护性基因的上调，包括参与视黄酸合成的醛脱氢酶1A2（Aldh1a2）和一种转化生长因子β拮抗剂核心蛋白聚糖。有趣的是，系膜细胞还显示出威尔姆斯瘤基因1（Wt1）的显著表达，该基因通常被认为是足细胞特异性的。Cd2ap突变足细胞显示蛋白酶以及参与肌肉和血管发育的基因上调，并显示出非常强烈的表明程序性细胞死亡的基因表达特征。内皮细胞显示白细胞粘附相关因子血管细胞粘附分子1（Vcam1）和选择素（Sele）以及中期因子（促进血管生成）、内皮素和许多对细胞因子和干扰素有反应的基因表达增加。
本研究全面分析了Cd2ap突变体中肾小球三种细胞类型的变化特性，确定了激活和抑制的途径及相关基因，从而对这种遗传病有了更深入的分子理解。
