Wang Fei, Tong Qiang
United States Department of Agriculture/Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA.
Am J Physiol Cell Physiol. 2008 Jul;295(1):C213-20. doi: 10.1152/ajpcell.00422.2007. Epub 2008 May 7.
PU.1 transcription factor is a critical regulator of hematopoiesis and leukemogenesis. Because PU.1 interacts with transcription factors GATA-2 and C/EBPalpha, and both are involved in the regulation of adipogenesis, we investigated whether PU.1 plays a role in the regulation of adipocyte differentiation. Our data indicate that PU.1 is expressed in white adipose tissue. PU.1 protein can also be detected in cultured 3T3-L1 adipocytes. Forced expression of PU.1 in 3T3-L1 cells inhibits adipocyte differentiation, whereas deletion of the transactivation domain of PU.1 abolishes this effect. The inhibition of adipocyte differentiation by PU.1 is achieved, at least in part, through repression of the transcriptional activity of C/EBPalpha and C/EBPbeta. Furthermore, GATA-2 and PU.1 have an additive inhibitory effect on C/EBP transactivation and adipogenesis. Finally, the expression of PU.1 is increased in white adipose of obese mice.
PU.1转录因子是造血作用和白血病发生的关键调节因子。由于PU.1与转录因子GATA-2和C/EBPα相互作用，且二者均参与脂肪生成的调节，因此我们研究了PU.1是否在脂肪细胞分化调节中发挥作用。我们的数据表明，PU.1在白色脂肪组织中表达。在培养的3T3-L1脂肪细胞中也能检测到PU.1蛋白。在3T3-L1细胞中强制表达PU.1可抑制脂肪细胞分化，而缺失PU.1的反式激活结构域则消除了这种效应。PU.1对脂肪细胞分化的抑制作用至少部分是通过抑制C/EBPα和C/EBPβ的转录活性实现的。此外，GATA-2和PU.1对C/EBP反式激活和脂肪生成具有累加抑制作用。最后，肥胖小鼠白色脂肪中PU.1的表达增加。
