Abstract: FR-PO705

Heterogeneous Nuclear Ribonucleoprotein F Deficiency Aggravates Podocyte Loss via Down-Regulation of Sirtuin-1 Expression in Adriamycin-Induced Nephropathy in Mice

Session Information

Category: Glomerular

  • 1002 Glomerular: Basic/Experimental Pathology

Authors

  • Lo, Chao-Sheng, CRCHUM, Universite de Montreal, Montreal, Quebec, Canada
  • Chenier, Isabelle, CHUM-Hotel Dieu Hosp, Montreal, Quebec, Canada
  • Filep, Janos G., Maisonneuve-Rosemont Hosp., Montreal, Quebec, Canada
  • Ingelfinger, Julie R., The New England Journal of Medicine, Boston, Massachusetts, United States
  • Zhang, Shao-Ling, Research Center of Centre Hospitalier de l Universite de Montreal (CRCHUM), Montreal, Quebec, Canada
  • Chan, John S.D., CRCHUM,University of Montreal, Montreal, Quebec, Canada
Background

We reported that overexpression of heterogeneous nuclear ribonucleoprotein F (hnRNP F) enhances sirtuin-1 expression and attenuates apoptosis in renal proximal tubular cells in db/db hnRNP F-transgenic mice (Diabetes 2017). In the present study, we investigated whether hnRNP F deficiency in podocytes would aggravate podocyte injury in adriamycin (ADR)-induced nephropathy in mice.

Methods

Podocyte-specific hnRNP F knockout (KO) mice were generated by crossbreeding podocin (Pod)-Cre mice with floxed hnRNP F mice on a C57BL/6 background. Male adult non-KO littermates (controls) and Pod-hnRNP F KO mice were studied at age 10 to 20 weeks. Body weight (BW) and urinary albumin/creatinine ratio (ACR) were monitored bi-weekly. To induce nephropathy, male controls and Pod-hnRNP F KO mice were administered ADR (doxorubicin) (18 mg/kg BW) via tail vein at the age of 10 weeks. Urinary ACR were assessed 7 and 11 days post-ADR. Mice were euthanized on day 12. Kidneys were processed for histology. Freshly isolated glomeruli were assessed for mRNA and protein expression by real time-qPCR and Western blotting, respectively. In addition, primary podocytes isolated from controls and Pod-hnRNP F KO mice ± ADR were studied in vitro.

Results

Pod-hnRNP F KO mice were phenotypically normal with a slight increase in ACR at week 20. Glomeruli isolated from POD-hnRNP F KO mice exhibited significantly lower mRNA and protein levels of sirtuin-1 and podocyte markers including nephrin, WT1 and synaptopodin than controls. Administration of ADR significantly increased urinary ACR and apoptotic podocytes in both groups. However, these changes were more pronounced in Pod-hnRNP F KO mice, parallel with significant decreases in sirtuin-1, nephrin, WT1 and synaptopodin expression. Finally, in vitro studies confirmed that primary podocytes from hnRNP F KO mice exhibited lower sirtuin-1 expression and higher acetylated p53 expression and apoptotic podocytes after ADR treatment.

Conclusion

HnRNP F deficiency aggravates podocyte apoptosis in ADR-induced nephropathy in mice, indicating a protective role for hnRNP F against podocyte injury.

Funding

  • Government Support - Non-U.S.