Abstract: FR-PO635

Vitamin D Receptor Agonist (VDA) Prevents Dedifferentiation of Podocytes through Down Regulation of MicroRNA193a in High Glucose Milieu

Session Information

Category: Diabetes

  • 501 Diabetes Mellitus and Obesity: Basic - Experimental

Authors

  • Mishra, Abheepsa, Feinstein Institute of Medical Research, Northwell Health, MANHASSET, New York, United States
  • Ayasolla, Kamesh R., Feinstein Institute for Medical Research, Great Neck, New York, United States
  • Kumar, Vinod, Fienstine Institute for Medical Research, New York, New York, United States
  • Lan, Xiqian, Feinstein Institute for Medical Research, Great Neck, New York, United States
  • Aslam, Rukhsana, Feinstein Institute for medical research, Glenoaks, New York, United States
  • Hussain, Ali, Feinstein Institute of Medical Research, New York, New York, United States
  • Marashi Shoshtari, Seyedeh Shadafarin, The Feinstein Institute for Medical Research, Manhasset, New York, United States
  • Malhotra, Ashwani, Feinstein Inst.Med research and NSLIJ, Manhasset, New York, United States
  • Singhal, Pravin C., North Shore LIJ Health System, Great Neck, New York, United States
Background

Both podocytes (PDs) and parietal epithelial cells (PECs) are derived from the same mesenchymal cells during embryogenesis. Expression of miR193a, which inversely regulates Wilms tumor (WT) 1 gene (the transcriptor of nephrin and podocalyxin) determines the net phenotype. Vitamin D receptor agonist (VDA) has been shown to down regulate miR193a in differentiating PECs. We hypothesize that if high glucose dedifferentiate PDs through up regulation of miR193a then VDA could prevent PDs dedifferentiation via down regulation of miR193a.

Methods

Differentiated (DIF)-PDs were incubated in media containing either buffer or high glucose (30 mM) for 48 hours (n=4). To evaluate the effect of VDR agonist, DIF-PDs were incubated in media containing a buffer, high glucose with/without VDA (EB1089, 1 nM) for 48 hours. To determine the effect of WT1 repressor complex on the PAX2 promoter in high glucose milieu, cellular lysates of control and high glucose treated PDs were immunoprecipitated with WT1 antibody and IP fraction was probed for DNMT1, EZH2, and menin. In vivo studies, four- months old wild-type and BTBRob/ob mice were administered either normal saline or normal saline + VDA (0.1 µg/Kg), intraperitoneally, every other day for 4 weeks. Renal cortical sections were labeled for WT1, synaptopodin, and PAX2. Renal cortical sections were labeled for miR193a by fluorescent in situ hybridization technique.

Results

High glucose down regulated (P<0.05 vs. control) PD expression of WT1, nephrin, podocalyxin but enhanced (P<0.01 vs. control) expression of PAX2 and miR193a. VDA not only down regulated PD expression of mIR193a and PAX2 but also upregulated (P<0.05 vs. control) expression of WT1. High glucose upregulated PD expression of PAX2 through disruption of WT1 repressor complex binding on PAX2 promoter. VDA treatment not only increased PD expression of WT1 but also displayed binding of WT1 repressor complex on the PAX2 promoter. Renal cortical sections of BTBRob/ob mice displayed enhanced PD expression of miR193a, decreased PD expression of WT1 and enhanced expression of PAX2.

Conclusion

High glucose dedifferentiates PD via up regulation of miR193a and VDA preserves PD phenotype in high glucose milieu by down regulating miR193a.

Funding

  • NIDDK Support