Ha Tae-Sun, Ha Dong-Soo
1 Department of Pediatrics, College of Medicine, Chungbuk National University, Cheongju, Korea.
2 Department of Pediatrics, Chungbuk National University Hospital, Cheongju, Korea.
J Med Food. 2019 Feb;22(2):170-177. doi: 10.1089/jmf.2017.4139. Epub 2019 Jan 2.
CD2-associated protein (CD2AP), an adaptor protein, plays several important roles in podocyte function, linking slit diaphragms to actin-based cytoskeleton and sending survival signals. Here, we investigated whether ginseng total saponin (GTS) had a protective role in the changes of podocyte CD2AP protein and podocyte apoptosis under in vitro diabetic conditions. Conditionally immortalized mouse podocytes cultured with normal glucose (5 mM) or high glucose (30 mM) and with or without advanced glycosylation end products were treated with GTS. We found that CD2AP co-localized with the F-actin fibers in podocyte cytoplasm using confocal imaging; however, diabetic conditions caused the podocytes to diminish and conglomerate CD2AP stainings in the peripheral cytoplasm, which were recovered by GTS. Diabetic conditions also suppressed CD2AP protein levels at 6 and 24 h in western blotting. These phenotypical changes of CD2AP protein were mitigated by GTS. Diabetic conditions also induced podocyte apoptosis at 24 h, which were attenuated by GTS. These findings provide a novel mechanism that diabetic conditions induce quantitative and qualitative changes of podocyte CD2AP protein and apoptosis, which would be restored by GTS.
CD2相关蛋白（CD2AP）是一种衔接蛋白，在足细胞功能中发挥多种重要作用，将裂孔隔膜与基于肌动蛋白的细胞骨架相连并传递存活信号。在此，我们研究了人参总皂苷（GTS）在体外糖尿病条件下对足细胞CD2AP蛋白变化和足细胞凋亡是否具有保护作用。用正常葡萄糖（5 mM）或高葡萄糖（30 mM）培养，并添加或不添加晚期糖基化终产物的条件性永生化小鼠足细胞，用GTS进行处理。我们通过共聚焦成像发现，CD2AP与足细胞细胞质中的F-肌动蛋白纤维共定位；然而，糖尿病条件导致足细胞减少，并使外周细胞质中的CD2AP染色聚集，而GTS可使其恢复。在蛋白质印迹法中，糖尿病条件在6小时和24小时时也会抑制CD2AP蛋白水平。GTS减轻了CD2AP蛋白的这些表型变化。糖尿病条件在24小时时还诱导足细胞凋亡，而GTS可使其减弱。这些发现提供了一种新机制，即糖尿病条件会诱导足细胞CD2AP蛋白的定量和定性变化以及凋亡，而GTS可使其恢复。
