Dr Jennifer Li1, Professor Stephen Alexander2, Associate Professor Natasha Rogers1
1Westmead Institute For Medical Research, Westmead, Australia, 2Children’s Hospital Westmead, Westmead, Australia
Aim: Investigate whether Gasdermin-D (GSDMD) and pyroptosis can be targeted to treated acute kidney injury (AKI).
Background: Pyroptosis, a pro-inflammatory form of cell death and is dependent on pore formation by cleaved Gasdermin-D. We hypothesis pyroptosis is important in renal ischemia-reperfusion injury (IRI).
Methods: GSDMD-I105N mice with isoleucine to asparagine mutation (I105N) in the GSDMD gene after ethyl-N-nitrosourea mutagenesis in wild-type (WT) C57BL/6 mice were used in the study. Chimeric mice were generated by whole body irradiation, followed by infusion of syngeneic donor bone marrow cells, and allowed to engraft for 8-weeks prior to experimentation. Disulfiram (DFM), which inhibits GSDMD pore formation was administered to WT-mice (26mg/kg in divided doses) for drug repurposing. Age- and gender-matched littermate control WT, GSDMDI105N, chimeric and DFM-treated mice were subjected to bilateral renal IRI (20min, 36°C) and biomolecular phenotyping was performed 24-hours later.
Results: Homozygote (HOM) and heterozygote GSDMD-I105N mice were protected from renal IRI in a gene dose-dependent manner when compared to WT, demonstrating lower mean serum creatinine (15.7, 48.1 and 85.5µmol/L respectively, p<0.001), with less histological injury and cell death (p<0.01) and decreased renal expression of pro-inflammatory mRNA (TNF-α, IL-1β, IL-6). Chimeric studies showed that HOM mice were protected from severe AKI, even with WT-derived bone marrow cells (Cr 51.3 vs 132 umol/L vs WT mice receiving HOM-bone marrow). WT-mice treated with DFM had lower serum Cr (35.3umo/L, p<0.001 vs WT) and widespread reduction in pro-inflammatory cytokine expression.
Conclusion: Impaired pyroptosis from GSDMD-I105N mutation limited IRI/AKI severity and renal expression of this mutation is critical to protection. Disulfiram, a known inhibitor of GSDMD, demonstrated promising results, with less AKI compared to untreated mice following IRI.
Biography:
Dr Jen Li is a nephrologist with interests in acute kidney injury, transplantation and precision medicine and is completing her PhD at the Westmead Institute for Medical Research. She is an editorial fellow with Transplantation and early career committee member with TSANZ and TTS.