Gene Networks promoting adipocyte cell differentiation and function

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A major goal of this laboratory is to understand the molecular mechanisms by which TFs and epigenomic modification control gene expression programs that regulate adipose tissue development and function. Adipogenesis begins with an established cascade of transcription factor (TF) activity that includes collaboration between the CCAAT/enhancer binding protein β (CEBPβ) and the glucocorticoid receptor (GR). A key goal of the present proposal is to determine how CEBPβ and its related paralogs bridge the transcriptional programs in multipotent stem cells and early differentiating pre-adipocytes, with a long-term objective of understanding a comprehensive TF network promoting adipose tissue development, growth and function. Specific Aim 1 comprehensively identifies the components of active enhancers during human adipogenesis. We will perform a state-of-the-art genomic/proteomic approach to determine the chromatin-associated proteins promoting adipocyte differentiation. Specific Aim 2 elucidates the mechanistic actions of networked TFs and co-regulators that control human adipogenesis and adipocyte function. Novel adipogenic roles for protein candidates identified in Aims 1 will be examined by mutational analysis and genome-wide approaches. As a whole, we will generate and integrate unique, orthogonal cistromic and enhancer proteomic datasets to reveal fundamental molecular mechanisms for transcriptional regulators in native chromatin. This will elucidate how CEBP proteins and GR perform unique biological functions, and address the more general question of how TFs recognize, access and act at their genomic-binding sites to control tissue-specific gene expression. Specific Aim 3 comprehensively identifies the components of active enhancers in adipose tissue. We hypothesize that comparison of the enhancer proteomes from visceral and subcutaneous white adipose tissues and from brown adipose tissue will reveal fundamental mechanisms controlling depot-specific gene expression and uncover the set of transcriptional regulators controlling lipid metabolism in vivo. Our focus on the development and function of adipose tissue is warranted given its importance in health and disease. Indeed, adipose tissue normally benefits health, yet in excess as in obesity, it becomes a strong risk for metabolic diseases including diabetes, hyperlipidemia, hypertension and heart disease. New insights into adipose biology will enhance its translational potential to combat the harmful and growing epidemics of obesity and diabetes.