Where does fat cell come from?
We are facing the epidemic of obesity nowadays. Obesity has been associated with multiple metabolic abnormalities including hypertension, atherosclerosis, diabetes, etc. The uncontrolled expansion of adipose tissue is the hallmark of obesity with both hypertrophy (increasing fat cell size) and hyperplasia (increasing fat cell number). Despite more and more attention and extensive studies over the past decade, the identity of fat cell progenitor is still elusive. In a recent issue of Cell, Rodeheffer and colleagues from Friedman group isolated and identified a population of cells which is capable of in vitro differentiation to fat cells and in vivo reconstitution of fat pads. The authors took advantage of FACS sorting to isolate potential precursor population from stromal vascular fraction of fat tissue. After rounds of sorting with different surface markers, they zoomed in Lin-CD29+CD34+Sca1+CD24+ cells which contribute ~0.8% to the whole stromal vascular cell population. In vitro diff
