Adipose-derived stem cells: Therapy through paracrine actions

Abstract

Adipose-derived stem cells (ADSC) reside in the stromal vasculature of adipose tissue, and are called stromal vascular fraction (SVF) cells when freshly isolated. These cells share many common features with bone marrow stem cells (BMSC), including cell surface marker expression and therapeutic potential. Due to their abundant tissue source and ease of isolation, SVF cells are the only stem cell type that can be isolated and transplanted autologously on a same-day basis. Preclinical studies have shown that freshly isolated SVF cells or cultured ADSC can treat a wide range of diseases and injuries, including cerebral hemorrhage, cardiac infarct, renal injury, urinary incontinence, and erectile dysfunction. All of these studies have shown or suggested that the mechanisms through which ADSC exert therapeutic efficacy are paracrine in nature. Reported evidence of cell differentiation is limited and can usually be explained by the presence of differentiated cells (e.g., smooth muscle) in the cell preparation and/or the use of “leaky” cell labels (e.g., DiI), nonspecific cell markers (e.g., nestin), and/or suboptimal histological images.