Kidney Week

Abstract: FR-PO992

Investigating Hepatocyte Nuclear Factor 4 Alpha as a Central Regulator of Kidney Graft Repair

Session Information

• Top Trainee Posters - 2
  October 25, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 01:00 PM - 02:00 PM

Category: Transplantation

• 2101 Transplantation: Basic

Authors

• Neupane, Slaghaniya, University of Toronto Temerty Faculty of Medicine, Toronto, Ontario, Canada

Slaghaniya Neupane

• Petrovic, Stefan, University Health Network, Toronto, Ontario, Canada

Stefan Petrovic

• Saha, Aninda Dibya, Stanford Medicine, Stanford, California, United States

Aninda Dibya Saha

• Allen, Maya A., University of Toronto Temerty Faculty of Medicine, Toronto, Ontario, Canada

Maya A. Allen

• Sachewsky, Nadia, University Health Network, Toronto, Ontario, Canada

Nadia Sachewsky, PhD

• John, Rohan, University Health Network, Toronto, Ontario, Canada

Rohan John, MD

• Selzner, Markus, University Health Network, Toronto, Ontario, Canada

Markus Selzner, MD

• Robinson, Lisa, Sick Kids Foundation, Toronto, Ontario, Canada

Lisa Robinson, MD, FASN

• Clotet Freixas, Sergi, McMaster University, Hamilton, Ontario, Canada

Sergi Clotet Freixas, PhD

• Konvalinka, Ana, University of Toronto Temerty Faculty of Medicine, Toronto, Ontario, Canada

Ana Konvalinka, MD, PhD

Background

Kidney transplantation is the optimal treatment for end-stage kidney disease. However, ischemia-reperfusion injury (IRI) harms all transplanted kidneys, limiting their short- and long-term survival. Previously, we determined that superior kidney function/structure after IRI is associated with preserved expression of mitochondrial proteins during normothermic ex vivo kidney perfusion (NEVKP). We identified a potential transcriptional regulator of these mitochondrial proteins, hepatocyte nuclear factor 4a (HNF4A), which may present a novel target for kidney repair. Our goal is to determine whether a novel HNF4A agonist, N-trans caffeoyltyramine (NCT), protects kidneys from IRI. We will evaluate the effectiveness of NCT treatment in vitro studying male and female primary proximal tubular cells (PTECs), and in vivo studying male and female mice.

Methods

First, we inhibited HNF4A in primary male and female PTECs, using a pharmacologic or genetic approach. We then assessed gene expression, cell death and mitochondrial function. Next, we treated PTECs with NCT/vehicle and examined cell death and expression of HNF4A target genes. Lastly, male and female mice were subjected to bilateral IRI, and kidney function and structure were assessed on post-operative day 2 and 14.

Results

HNF4A inhibition in vitro increased PTEC death and decreased mitochondrial function, while NCT increased the expression of HNF4A and mitochondrial genes, suggesting that NCT may be protective. We developed a sex-specific model of bilateral IRI and demonstrated that warm ischemia (27-minutes in males, 40-minutes in females) impairs kidney function on post-operative day 2, indicated by elevated serum creatinine and tubular injury. Mice also developed tubulointerstitial fibrosis on post-operative day 14.

Conclusion

Based on the preliminary results, HNF4A is important for the metabolic function and viability of PTECs. We will next administer NCT to mice prior to IRI and examine whether HNF4A agonist preserves mitochondria and improves kidney function and structure.