Abstract: SA-PO214

Paricalcitol Prevents PAN-Induced Podocyte Morphological Change via Direct Regulation of Nestin Transcription through the Interaction of VDR/VDRE

Session Information

  • Glomerular: Cell Biology
    November 04, 2017 | Location: Hall H, Morial Convention Center
    Abstract Time: 10:00 AM - 10:00 AM

Category: Glomerular

  • 1003 Glomerular: Cell Biology

Authors

  • Zhang, Yuling, Huashan Hospital, Shanghai, China
  • Jiang, Xinxin, Huashan Hospital, Shanghai, China
  • Dong, Xinyu, Huashan Hospital affiliated to Fudan University, Shanghai, China
  • Chen, Jing, Huashan Hospital affiliated to Fudan University, Shanghai, China
Background

Podocyte morphological change is a pathologic feature of a variety of chronic kidney disease. Several lines of evidence suggested a potential protecting role of vitamin D in podocytes, but the underlying mechanism remained unclear. We hypothesized that vitamin D analogue paricalcitol restored podocytes morphology in puromycin aminonucleoside (PAN) induced nephrosis by modulating nestin gene expression

Methods

A rat model of podocyte injury was created by a single intraperitoneal injection of PAN and subjected to either saline or paricalcitol. Proteinuria, podocyte foot process effacement (FPE), expression of nestin and vitamin D receptor (VDR) in glomeruli was evaluated. The influence of PAN or paricalcitol on cultured mouse podoctyes were also observed. VDR expression was silenced by VDR siRNA or plasmids containing VDR shRNA transfection. Chromatin immunoprecipitation (ChIP) and luciferase reporter assays were performed to study the connection between VDR and nestin gene expression.

Results

Paricalcitol significantly alleviated PAN-induced proteinuria and podocyte FPE. This protective effect was accompanied by an increased expression of VDR in the glomeruli. Paricalcitol also inhibited PAN-induced glomeruli nestin overexpression. In vitro study showed that PAN significantly inhibited VDR protein expression and stimulated nestin protein expression which resulted in nestin filament derangement. Paricalcitol treatment abolished the effect. Downregulation of VDR in cultured podocytes also resulted in overexpression and derangement of nestin. ChIP assays revealed a VDR response element (VDRE) in nestin promoter and paricalcitol enhanced the binding of VDR and VDRE. Luciferase reporter assays of the nestin promoter fragment showed paricalcitol effectively repressed nestin reporter gene expression after PAN treatment. However, paricalcitol treatment alone showed no influence on luciferase activity. Mutation of VDRE abolished the effect.

Conclusion

Paricalcitol prevents morphological change of podocytes in PAN nephrosis via direct regulation of nestin trascription through the interaction of VDR/VDRE.

Funding

  • Government Support - Non-U.S.