Back from the brink: a mesenchymal stem cell infusion rescues kidney function in acute experimental rhabdomyolysis

Systemic administration of mesenchymal stem (stromal) cells (MSCs) has shown benefit in a range of experimental models of acute kidney injury, although the reported mechanisms of action and requirement for MSC localization to the kidney have varied. Geng and colleagues now demonstrate that a single intravenous infusion of MSCs given 6 hours after induction of acute muscle necrosis (rhabdomyolysis) robustly ameliorates the resulting acute kidney injury and promotes early intra-renal accumulation of CD206+ (M2) macrophages. The benefit occurred in the absence of MSC localization to the kidney and could be reproduced by adoptive transfer of ex vivo-programmed M2 macrophages.