Identification and characterization of progenitor/stem cells that give rise to different adipose depots
The adipose tissue arises from the multipotent stem cells of mesodermal origin. When triggered by appropriate developmental cues, these cells become committed to the adipocytes lineage. It has been suggested that different fat depots located in different anatomical locations of the body may derive from distinct developmental origins. Recently, we have identified and isolated a subpopulation of adipogenic progenitors (Sca-1+/CD45-/Mac1-; referred to as Sca-1+ progenitor cells, ScaPCs) residing in murine brown fat, white fat, and skeletal muscle. ScaPCs derived from different tissues possess unique molecular expression signatures and adipogenic capacities. Importantly, while the ScaPCs from interscapular BAT are constitutively committed brown fat progenitors, Sca-1+ cells from skeletal muscle and subcutaneous white fat are highly inducible to differentiate into brown-like adipocytes upon stimulation with BMP7. ScaPCs from obesity-resistant mice exhibit markedly higher thermogenic capacity compared to cells isolated from obesity-prone mice. Currently, ongoing studies in Dr. Tseng’s lab are to further define these progenitors by single cell analysis, microRNA profiling and in vivo fate mapping.