Differential expression of signal transducers and activators of transcription during human adipogenesis

Signal Transducers and Activators of Transcription (STATs) display unique e xpression patterns upon induction of differentiation of murine 3T3-L1 pread ipocytes into adipocytes. During differentiation, expression of STAT1 and S TATE increase, while STAT3 and STAT6 remain relatively unchanged. Here, we determined whether human subcutaneous preadipocytes expressed STATs and if the pattern of expression changed during adipogenesis. We found by Western blot analysis that freshly isolated preadipocytes expressed STAT1, STAT3, S TATE, and STAT6, but not STAT2 and STAT4. Induction of preadipocyte differe ntiation with 1-methyl-3-isobutylxanthine, dexamethasone, insulin, and BRL4 9653 decreased expression of STAT1, and increased expression of STAT3 and S TATE. STAT6 expression did not change during adipogenesis. Changes in expre ssion of CCAAT/enhancer binding protein beta (C/EBP beta), C/EBP delta, C/E BP alpha, and peroxisome proliferator-activated receptor gamma were similar to murine cell lines. These results suggest that unlike the traditional ad ipogenic transcription factors, unique differences exist in STAT expression patterns between murine and human adipose cells, (C) 2001 Academic Press.