Abstract: SA-PO0753
Parietal Epithelial Cell Transcriptional Profiling from Pax2 Mutant Mice Is Consistent with Impaired Regeneration After Podocyte Injury
Session Information
- Glomerular Diseases: Profiling Through Multiomics
November 08, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1401 Glomerular Diseases: Mechanisms, including Podocyte Biology
Authors
- Cunanan, Joanna, Division of Nephrology and Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada
- Zhang, Daniel, Division of Nephrology and Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada
- De Gregorio, Vanessa Sara, Division of Nephrology and Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada
- Ricardo, Samantha, Division of Nephrology and Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada
- Barua, Moumita, Division of Nephrology and Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada
Background
Podocyte loss in glomerular disease is difficult to treat due to their terminal differentiation. Parietal epithelial cells (PECs), which express developmental markers like PAX2, may contribute to podocyte regeneration. Our previous work suggests impaired PEC-mediated repair in mice with a Pax2 missense mutation, which develop worsened FSGS after podocyte injury compared to controls. Here, we used single nucleus RNA sequencing (snRNA-seq) to investigate the molecular basis of this defect, focusing on PEC cell clusters post-injury.
Methods
Glomeruli from Adriamycin-injured Pax2 mutant mice were isolated using Dynabeads, minimizing collagenous digestion to preserve the Bowman’s capsule for PEC enrichment, which are often missed in single cell RNA sequencing studies due to their sparsity. snRNA-seq (10X Genomics) was processed with Seurat in RStudio. Cell types were identified using canonical markers (Chung et al., JASN 2020), and Gene Ontology (GO) analysis was performed.
Results
In PECs, GO analysis revealed downregulation of pathways essential for podocyte regeneration, including podocyte and glomerular epithelial development, adherens junction assembly, IL-6 signaling, Hippo signaling, and plasma membrane organization. These changes suggest impaired epithelial integrity, differentiation, and reparative signaling. In contrast, PECs showed upregulation of metabolic pathways (e.g., proline, glucuronate metabolism), possibly reflecting a maladaptive stress response. The POD/PEC cluster showed downregulated developmental, adhesion, and morphogenesis pathways, indicating impaired differentiation. Although anti-apoptotic signaling was upregulated in POD/PEC cells, this occurred without regenerative program activation.
Conclusion
Together, these findings suggest that after Adriamycin-induced podocyte injury, PECs and transitional POD/PEC cells in Pax2 mutant glomeruli fail to activate key developmental programs needed for podocyte regeneration and instead adopt transcriptional states that are metabolically altered but likely not pro-reparative.