320-OR: Pyruvate Kinase M2 (PKM2) Activation in the Podocyte Prevented Subset Differentiation of Glomerular Cells Induced by Diabetes

Pyruvate kinase M2 (PKM2) activation in the glomeruli has been reported as a potential protective factor against diabetic nephropathy (DN). We have previously found that systemic or local activation of PKM2 in the podocyte could reversed mitochondrial dysfunction, glomerular metabolism and pathology in diabetic mice, partially via its regulation of paracrine action of vascular endothelial growth factor (VEGF) against the toxicity of hyperglycemia. To further investigate the protective function of PKM2 in glomerular cell differentiation and gene expressions induced by diabetes, unbiased single-cell RNA sequencing (scRNA-seq) was performed using glomerular cells from mice with PKM2-specific overexpression in podocytes (PPKM2Tg) or WT mice, with or without 7 months of diabetes. High-qualitied glomerular cells (N=87,283) were isolated and sequenced, with > 98% from glomeruli, including 43% endothelial cells (EC), 31% podocytes, 14% mesangial cells (MC), 2% of parietal epithelial cells (PEC), 8% immune cells (macrophages, B cells, T cells, NK cells and neutrophils). Diabetes increased macrophage and B cell numbers from 2.2% to 4.8% and 0.35% to 1%, respectively. Although diabetes or PKM2 overexpression did not change the percentage of EC, MC and podocytes, phenotype switch occurred within subsets of these cells. Diabetes increased podocyte subsets enriched for stressed proteins, while decreased subsets enriched for ECM production and CDC42 GTPase cycle, which were involved in cytoskeleton and foot process formation. These phenotype switches induced by diabetes were reversed in PPKM2Tg mice. Further, MC subset with high expression of mitochondrial electron transport chain and TCA cycle, and EC subset with anti-inflammatory phenotype were reduced by diabetes and restored in PPKM2Tg mice. Thus, PKM2 overexpression in the podocyte changed the energy metabolism and differentiation of subsets of podocyte, MC and EC to protect from DN.