Figure 2.

The link between renal fibrosis and MSCs. MSCs, as the protectively fibrotic mediators, play the crucial role in the former 3 phases during the renal fibrotic process. Phase 1: activation and injury phase. Renal diseases lead to epithelial cell injury (E-cadherin shedding), fibroblast proliferation, and macrophage infiltration. Phase 2: fibrogenic signaling phase. Inflammatory and fibrotic signaling pathways are activated. Phase 3: fibrogenic phase. EMT increase and ECM deposition (EMT also could cause ECM deposition). Phase 4: destructive phase. Fibronectin, collagens, α-SMA increase, and finally renal failure.