Characterization of a human preadipocyte cell strain with high capacity for adipose differentiation

OBJECTIVE: To develop and to characterize a human preadipocyte cell strain with high capacity for adipose differentiation serving as a model for study ing human adipocyte development and metabolism in vitro. METHODS: Cells were derived from the stromal cells fraction of subcutaneous adipose tissue of an infant with Simpson-Golabi-Behmel syndrome (SGBS). Ad ipose differentiation was induced under serum-free culture conditions by ex posure to 10 nM insulin, 200 pM triiodothyronine, 1 muM cortisol and 2 muM BRL 49653, a PPAR; agonist. RESULTS: During the differentiation process SGBS cells developed a gene exp ression pattern similar to that found in differentiating human preadipocyte s with a characteristic increase in fat cell-specific mRNAs encoding lipopr otein lipase (LPL), glycero-3-phosphate dehydrogenase (GPDH), GLUT4, leptin and others. Differentiated SGBS cells exhibited an increase in glucose upt ake upon insulin stimulation and in glycerol release upon catecholamine exp osure. SGBS adipocytes were morphologically, biochemically and functionally identical to in vitro differentiated adipocytes from healthy subjects. How ever, while preadipocytes from healthy control infants rapidly lost their c apacity to differentiate after a few cell divisions in culture, SGBS cells maintained their differentiation capacity over many generations: upon appro priate stimulation 95% of SGBS cells of generation 30 developed into adipoc ytes. A mutation in the glypican 3 gene was not detected in the patient. Th us, it remains unclear whether the molecular alteration in SGBS cells is al so responsible for the high differentiation capacity and further investigat ions are required. CONCLUSION: The human cell strain described here provides an almost unlimit ed source of human preadipocytes with high capacity for adipose differentia tion and may, therefore, represent a unique tool for studying human fat cel l development and metabolism.