Abstract: TH-PO085

HIV Activates Epithelial Mesenchymal Transition (EMT) and Mammalian Target of Rapamycin (mTOR) Pathway in Parietal Epithelial Cells (PECs) via Down Regulation of MicroRNA193a

Session Information

Category: Glomerular

  • 1002 Glomerular: Basic/Experimental Pathology

Authors

  • Kumar, Vinod, Fienstine Institute for Medical Research, New York, New York, United States
  • Singhal, Pravin C., North Shore LIJ Health System, Great Neck, 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
  • Bhooplapur, Manali, Feinstein Institute for medical research, Glenoaks, New York, United States
  • Chowdhary, Sheetal, Feinstein Institute of Medical Research, New York, New York, United States
  • Meyer-Schwesinger, Catherine, University of Hamburg, Hamburg, Germany
  • Malhotra, Ashwani, Feinstein Inst.Med research and NSLIJ, Manhasset, New York, United States
Background

Micro-RNA (miR) 193a has been considered to be a tumor suppressor gene and its down regulation has been reported to stimulate EMT and mTOR pathways in cancer cells. HIV-associated nephropathy is characterized by collapsing variant of focal segmental glomerulosclerosis; in this glomerular phentype, proliferating cells in Bowman's space are considered to be of PEC lineage; however, the involved mechanism for PECs proliferation in HIV milieu is not clear. We asked whether HIV was inducing PECs proliferation through down regulation of miR193a.

Methods

Vector (PECV) - and HIV (NL4-3; PECHIV)-transduced human immortalized PECs were growth arrested and then incubated media (containing 1% serum) for 48 hours (n=4). In another set of experiments, PECs were incubated in media containing either buffer (control) or a microRNA193a inhibitor (25 nM) for 48 hours (n=4). To examine a causal relationship, PECV and PECHIV were transfected with either control or miR193a plasmids (n=4). In vivo studies, kidneys were harvested from 4- week old control (FVB/N) and HIV-transgenic (Tg26) mice. Proteins and RNAs were extracted. Protein blots were probed for EMT (α-SMA, SNAIL, and fibronectin), mTOR (p-mTOR, p-P70S6k, p-4EBP, and p-eEF)) markers and reprobed for actin. RNAs were assayed for miR193a.Renal cortical sections were immunolabeled for α-SMA, SNAIL, and p-mTOR.

Results

PECHIV and renal tissues of HIVAN mice displayed enhanced (P<0.05 vs. PECV/FVB/N) expression of EMT markers including alpha-SMA, fibronectin, and SNAIL. Similarly, PECHIV and renal tissues of HIVAN mice showed enhanced (P<0.05 vs. PECV/FVB/N) expression of p-mTOR, p-P70S6K, and p-4EBP and down regulation (P<0.05 vs.PECV/FVB/N) of p-eEF, indicating activation of mTOR pathway. PECHIV and renal tissues of HIVAN mice displayed 4 fold decreases in miR193a levels when compared to respective controls. Inhibition of miR193a in PECs, stimulated EMT and mTOR pathways. On the other hand, overexpression of miR193a in PECHIV attenuated activation of EMT and mTOR pathways.

Conclusion

HIV induces activation of growth pathways in PECs. This effect of HIV is mediated through down regulation of miR193a in PECs.

Funding

  • NIDDK Support