Fellow, Pediatric nephrology The Children's Hospital at Montefiore Bronx, New York, United States
Background: The Partitioning-defective (Par1) proteins are a family of apico-basal polarity proteins contribute to podocyte differentiation and glomerular development in Drosophila and mice, however their role in podocyte injury is not known. Objective: We hypothesized Par1a/b (aka Mark2 and Mark3) are protective against podocyte injury. Design/Methods: To test this hypothesis, we generated podocyte specific Par1a/b knockout mice. We used CRISPR to make two flox mice lines: Mark2 flox mice have flox sites flanking Par1b (Mark2) exons 2-4 and Mark3 flox mice have flox sites flanking Par1a (Mark3) exon 5-7. These mice were bred with NPHS2-Cre mice to generate NPHS2-Cre: Mark2flox/flox: Mark3 flox/flox (podocyte Par1a/b cKO) mice which were maintained on a on a C57BL6 background. To determine the effect of podocyte injury, adult 8 week old podocyte Par1a/b cKO mice were injected with adriamycin (15mg/kg). Controls included Adriamycin injected Mark2flox/flox: Mark3flox/flox mice and vehicle injected mice. Mice were euthanized at 14 weeks to analyze the kidney phenotype. Urine was collected to assess albumin:creatinine ratios. To examine the severity of Adriamycin nephropathy, Periodic-acid Schiff staining was performed to assess glomerular structural changes as well as immune-histochemistry for WT-1 and other podocyte markers. Results: Podocyte specific Par1a/b cKO mice survive to adulthood and did not die early following Adriamycin injection compared to control groups. Additional analyses are ongoing.
Conclusion(s): We will determine how podocyte Par1a/b deletion effects the severity of glomerular injury.
