Supplementary Material for: Dendrin Location in Podocytes Is Associated with Disease Progression in Animal and Human Glomerulopathy

Background: Adriamycin (ADR) nephrosis in mice has been extensively studied and has enabled a greater understanding of the processes underlying the progression of renal injury. Dendrin is a novel component of the slit diaphragm with proapoptotic signaling properties, and it accumulates in the podocyte nucleus in response to glomerular injury in mice. The present study re-evaluated chronic progressive nephropathy in ADR mice and the localization of dendrin in mice and in human glomerulopathy. Methods: To investigate the localization of dendrin, a mouse model of nephrosis and glomerulosclerosis was used, in which ADR was injected once. WT-1-positive cells and apoptotic cells were counted in vivo and in vitro. To check the expression of dendrin in ADR mice, immunostaining and Western blot were performed. A survey of dendrin staining was performed on human kidney biopsy specimens. Results: The injection of ADR induced proteinuria, podocyte loss and glomerulosclerosis. It also caused the relocation of dendrin from the slit diaphragm to the podocyte nucleus. We demonstrated the location of dendrin to podocyte nuclei in several cases of human glomerulopathy. The mean occurrence of dendrin-positive nucleus per glomerulus increased in several cases of human glomerulopathy. Conclusions: These findings suggest that the relocation of dendrin to the podocyte nuclei is useful as a novel marker of podocyte injury in human glomerulopathy.研究背景：小鼠阿霉素（Adriamycin, ADR）肾病已被广泛研究，为学界深入理解肾损伤进展的潜在分子机制提供了重要依据。树胶蛋白（Dendrin）是一类具备促凋亡信号传导特性的新型裂孔隔膜（slit diaphragm）组分，在小鼠发生肾小球损伤时，其会在足细胞（podocyte）细胞核内蓄积。本研究重新评估了ADR小鼠的慢性进行性肾病，以及树胶蛋白在小鼠与人类肾小球病中的定位情况。 实验方法：为探究树胶蛋白的定位特征，本研究采用单次注射ADR构建的肾病合并肾小球硬化小鼠模型，分别在体内及体外计数WT-1阳性细胞与凋亡细胞。为检测ADR小鼠体内树胶蛋白的表达水平，本研究开展了免疫染色与蛋白质印迹（Western blot）实验；同时对人类肾脏活检标本进行了树胶蛋白染色检测。 实验结果：单次注射ADR可诱导蛋白尿、足细胞丢失及肾小球硬化，同时促使树胶蛋白从裂孔隔膜向足细胞细胞核转位。本研究在多例人类肾小球病病例中证实了树胶蛋白定位于足细胞细胞核的现象，且每肾小球内树胶蛋白阳性细胞核的平均数量在上述病例中均显著升高。 研究结论：上述研究结果表明，树胶蛋白向足细胞细胞核的转位可作为人类肾小球病中足细胞损伤的新型生物标志物。