Podocyte Heterogeneity in Diabetic Kidney Disease: Deciphering the Metabolic Subtype and Its Cross-Talk with Parietal Epithelial Cells

Background: Podocyte injury critically contributes to diabetic kidney disease (DKD) progression, yet the cellular heterogeneity of podocytes and their distinct contributions to disease progression remains poorly characterized. Methods: Single-cell RNA sequencing (scRNA-seq) was performed on kidneys from db/db (n=4) and db/m (n=4) mice to identify podocyte subtypes. We analyzed their functional characteristics, key transcription factors, interactions with parietal epithelial cells (PECs), and clinical relevance. Results: Podocyte heterogeneity was mapped through single-cell RNA sequencing analysis.We identified three distinct subtypes: Cryab+ metabolic subtype (Metab-subtype), Slc6a6+ transitional phenotype (Trans-subtype), Magi2+ adhesion subtype (Differentiated-subtype). Trajectory analysis indicated that both the Trans-subtype and Differentiated-subtype originated from the Metab-subtype. Transcription factor analysis suggested that Wt1 may play a key role in subpopulation conversion. Conjoint trajectory analysis of podocytes and PECs revealed impaired differentiation of Cryab+ PECs into Cryab+ podocytes in DKD. We further uncovered intercellular crosstalk between Cryab+ podocytes and PECs, predominantly mediated by the VEGFA-NRP2 and APP-SORL1 ligand-receptor pairs. Clinically, the Cryab+ subtype exhibited a negative correlation with proteinuria and serum creatinine but a positive correlation with eGFR, suggesting that its decline contributes to unfavorable prognosis of DKD . Conclusion: These findings provide novel insights into podocyte heterogeneity and regeneration in DKD, highlighting potential therapeutic targets. Funding: Government Support – Non-U.S.Single-Cell RNA Sequencing Reveals Podocyte Heterogeneity: Three Distinct Subtypes and Pseudotemporal Dynamics of Podocyte-PEC Interactions in Diabetic Nephropathy