Fig. 1
From: Emerging roles of mesenchymal stem cell therapy in patients with critical limb ischemia
Major sources of mesenchymal stem cells (MSCs) and potential mechanisms of MSCs therapy in limb ischemia. MSCs are isolable from several sources. They restore tissue function and repair ischemic tissue via immunomodulation and angiogenesis. MSCs suppress inflammation and promote immunomodulation by secreting immunomodulatory cytokines, which stimulate the induction of M2 macrophages and increase the number of circulating regulatory T cells, resulting in an increase in interleukin IL-10 and resolution of inflammation. Additionally, MSCs release factors that promote angiogenesis directly. The possible mechanism by which MSCs mediate angiogenesis via direct dedifferentiation or through paracrine effects on effector cells such as smooth muscle cells, endothelial cells, and pericytes in the formation of mature vessels. ADT adipose tissue, BM bone marrow, CLI critical limb ischemia, ECs endothelial cells, iDC immature dendritic cell, mDC mature dendritic cell, MO monocyte, MQ-M2 macrophage M2, MSC mesenchymal stem cells, NK natural killer cells, PB peripheral blood, SMCs smooth muscle cells, T-reg regulatory T cell, UCB umbilical cord blood