Metformin inhibits chronic kidney disease-induced DNA damage and senescence of mesenchymal stem cells.

Mesenchymal stem cells (MSCs) are promising source of cell-based regenerative therapy. In consideration of the risk of allosensitization, autologous MSC-based therapy is preferred over allogenic transplantation in patients with chronic kidney disease (CKD). However, it remains uncertain whether adequate cell functionality is maintained under uremic conditions. As chronic inflammation and oxidative stress in CKD may lead to the accumulation of senescent cells, we investigated cellular senescence of CKD MSCs and determined the effects of metformin on CKD-associated cellular senescence in bone marrow MSCs from sham-operated and subtotal nephrectomized mice and further explored in adipose tissue-derived MSCs from healthy kidney donors and patients with CKD. CKD MSCs showed reduced proliferation, accelerated senescence, and increased DNA damage as compared to control MSCs. These changes were significantly attenuated following metformin treatment. Lipopolysaccharide and transforming growth factor β1-treated HK2 cells showed lower tubular expression of proinflammatory and fibrogenesis markers upon co-culture with metformin-treated CKD MSCs than with untreated CKD MSCs, suggestive of enhanced paracrine action of CKD MSCs mediated by metformin. In unilateral ureteral obstruction kidneys, metformin-treated CKD MSCs more effectively attenuated inflammation and fibrosis as compared to untreated CKD MSCs. Thus, metformin preconditioning may exhibit a therapeutic benefit by targeting accelerated senescence of CKD MSCs.