Adipose Injury-Associated Factors Mitigate Hypoxia in Ischemic Tissues through Activation of Adipose-Derived Stem/Progenitor/Stromal Cells and Induction of Angiogenesis

Based on the analysis of exudates from injured adipose tissue, we prepared a mixture containing the injury-associated growth factors at the same proportion as the exudates, named adipose injury cocktail (AIC). We hypothesized that AIC induces a series of regenerating and angiogenic processes without actual wounding. The purpose of this study is to elucidate the therapeutic potentials of AIC. AIC preferentially activated adipose-derived stem/progenitor/stromal cells (ASCs) to proliferate, migrate, and form networks compared with vascular endothelial cells, whereas vascular endothelial growth factor did not induce mitogenesis or chemotaxis in human ASCs. Each component growth factor of AIC was differently responsible for the ASC activation. AIC-treated ASCs tended to differentiate into adipocytes or vessel-constituting cells rather than into other cell types. In ischemic adipose tissues of mice, induced by either a surgical intervention or diabetes, AIC administration enhanced proliferation, especially of CD31(-)/CD34(+) ASCs, and mitigated tissue hypoxia by increasing capillary density and reducing fibrogenesis. These results suggest that AIC may have therapeutic potentials for various ischemic/hypoxic conditions by inducing adipose remodeling and neovascularization through activation of ASCs and other cells. Treatment with AIC has many advantages over cell-based therapies regarding morbidity, cost, and physical risks and may be used as an alternative therapy for improving tissue oxygen. (Am J Pathol 2011, 178:2322-2332; 10.1016/j.ajpath.2011.01.032)