Figure 1.

Figure 1A. Vascular repair by endogenous resident ECs. Vascular ECs are injured and undergo apoptosis or necrosis. The cell-cell junctions between injured ECs and resident adjacent ECs are destroyed and intercellular factors are released, which may in turn trigger the proliferation of endogenous resident ECs proliferate to replace injured ECs.

Figure 1B. Vascular repair by exogenous pluripotent stem cells (PSCs) derived ECs/EPCs. Injected exogenous EPCs derived from ESC/iPSC or directly reprogrammed fibroblasts can integrate into the blood vessel and replenish damaged vascular cells.

Figure 1C. Vascular repair by circulating EPCs. Circulating EPCs can secrete microparticles and paracrine growth factors which activate resident ECs to proliferate and regenerate the injured vasculature

Resident vascular ECs

Injured resident ECs

Paracrine factors released from injured ECs

Activated resident ECs

Exogenous ECs/EPCs derived from PSCs or directly reprogramed fibroblasts

Endogenous circulating EPCs

Microparticles and paracrine factors secreted by circulating EPCs