GPC3-mediated metabolic rewiring of diabetic mesenchymal stromal cells enhances their cardioprotective functions via PKM2 activation

Mesenchymal stromal cells (MSC) are promising stem cell therapy for treating cardiovascular and other degenerative diseases. Diabetes affects the functional capability of MSC and impedes cell-based therapy. Despite numerous studies, the impact of diabetes on MSC myocardial reparative activity, metabolic fingerprint, and the mechanism of dysfunction remains inadequately perceived. We demonstrated that the transplantation of diabetic-MSC (db/db-MSC) into the ischemic myocardium of mice does not confer cardiac benefit post-MI. Metabolomic studies identified defective energy metabolism in db/db-MSC. Furthermore, we found that glypican-3 (GPC3), a heparan sulfate proteoglycan, is highly upregulated in db/db-MSC and is involved in metabolic alterations in db/db-MSC via pyruvate kinase M2 (PKM2) activation. GPC3-knockdown reprogrammed-db/db-MSC restored their energy metabolic rates, immunomodulation, angiogenesis, and cardiac reparative activities. Together, these data indicate that GPC3-metabolic reprogramming in diabetic MSC may represent a strategy to enhance MSC-based therapeutics for myocardial repair in diabetic patients.