Figure 2. Paracrine-autocrine mechanisms in stem cell signaling and therapy.
ASCs release biologically active substances in a temporal and spatial manner in response to specific environmental stimuli such as ischemia. These factors influence the microenvironment by exerting paracrine actions on different cell types leading to tissue protection, repair and regeneration. The putative factors may also exert autocrine actions modulating the biology of stem cells including self-renewal and proliferation.