Figure 1.

Model for paracrine actions of MSCs on the injured tubule. After an acute kidney injury, injected MSCs home to injury sites and may be recruited from endogenous niches (bone marrow or kidney) as well. MSCs bind to glomerular and/or peritubular capillary endothelium and both protect the kidney from further injury and accelerate repair. Paracrine mediators play important roles in repair, including VEGF, IGF, HGF, PGE₂, and other soluble factors that exert mitogenic, antiapoptotic, proangiogenic and anti-inflammatory effects [17].