Figure 1

IGF-1 induces lipid production in immortalized sebocytes. (a) Primary sebocytes were cultured from isolated sebaceous gland and then immortalized using the recombinant retrovirus expressing simian virus 40 T antigen (SV-sebocytes). (b) SV-sebocytes were grown on cover glasses to 70–80% confluence, and then cultured with fresh medium without FBS and rhEGF. After an overnight incubation, cells were treated with IGF-1 (50 ng/ml) for 24 h. Intracellular lipid droplets were visualized using Oil red O staining. IGF-1 increased lipid production in sebocytes. (c) Intracellular lipids were analyzed using thin layer chromatography (TLC). IGF-1 increased the production of lipids, including squalene, wax ester, triglyeride and cholesterol. Quantification of lipids was carried out using ImageJ program. Data are represented as a percentage of the control. (d) The levels of lipogenic regulators were detected using Western blotting. IGF-1 increased the levels of lipogenic regulatory proteins in a dose-dependent manner. β-Actin was used as a loading control.