(A) GFP- and GFP+ SV cells from PPARγ-GFP mice were sorted, plated, cultured to confluence and insulin-stimulated adipogenesis was examined with the lipid-specific stain Oil Red O (red).
(B) Sorted GFP+ SV cells were cultured in media or media supplemented with insulin and then stained with Nile Red, a lipid-specific fluorescent dye, to simultaneously visualize fat accumulation and GFP expression.
(C) Left panel: qPCR analysis of the indicated markers in sorted GFP+ cells before (green bars) and after (blue bars) insulin-stimulated adipogenesis. C/EBPα is an adipogenic transcription factor; leptin, adiponectin (ADPN), and adipsin are adipokines; Pref-1 is a preadipocyte marker whose expression inversely correlates with adipogenesis. Right panels: SV cells from P30 PPARγ-GFP adipose depots were examined for GFP (green) and perilipin (red, an adipocyte marker) expression both before (top) and after (bottom) adipogenic induction. Nuclei stained with DAPI (blue).
(D, E, F) FACS-isolated GFP+ SV cells were implanted into nude mice and the tissue that formed after 1 month was photographed with bright field (D, left panel) and fluorescent microscopy (D, right panel) and examined with H&E staining (E, left panel), GFP fluorescence and Nile Red staining (E, right panel), and GFP fluorescence and perilipin immunochemistry (F).
(G) Left panel: P30 PPARγ-GFP adipose depot SV cells were examined for Sca-1 and GFP expression with flow cytometry. The box indicates the Sca1+GFP+ double positive population. Right panels: IWAT (adipose, top) and SV cells (bottom) of aP2-GFP transgenics were analyzed for GFP expression, which was present in adipocytes but not SV cells. PPARγ-GFP serves as a control. Nuclei stained with DAPI (blue).
(H) qPCR analyses of the indicated markers of FACS-isolated GFP+ SV cells (green bars) and floated adipocytes (blue bars).
(I) GFP- SV cells, GFP+ SV cells and adipocytes were subjected to gene expression profiling. The heatmap illustrates 152 genes that differentiate GFP+ SV cells from the other populations. The red depicts a ≥2-fold increase in gene expression while the green depicts a ≤2-fold decrease in gene expression.
Scale bars: 50μm (A-C, E, G right panel bottom row), 2mm (D, G right panel top row), 20μm in confocal images (F).