Project description:Brown fat dissipates energy as heat and protects against obesity. Here, we identified nuclear factor I-A (NFIA) as a novel transcriptional regulator of brown fat by a genome-wide open chromatin analysis of murine brown and white fat followed by motif analysis of brown-fat-specific open chromatin regions. NFIA and the adipogenic master regulator, PPARgamma, co-localize at the brown-fat-specific enhancers. Moreover, the binding of NFIA precedes and facilitates the binding of PPARgamma, leading to increased chromatin accessibility and active transcription. Introduction of NFIA into myoblasts results in brown adipocyte differentiation. Conversely, the brown fat of NFIA knockout mice displays impaired expression of the brown-fat-specific genes and reciprocal elevation of muscle genes. Finally, expression of NFIA and the brown-fat-specific genes is positively correlated in human brown fat. These results indicate that NFIA is a key transcriptional regulator of brown fat and exerts its effects by co-localizing with PPARg at cell-type-specific enhancers.
Project description:We performed ChIP-seq to chart genome-wide maps of H3K27me3 in brown preadipocytes and mature brown adipocytes. We observed a subset of brown fat-specific genes, but not common fat genes or white fat-specific genes, possess the H3K27me3 mark in preadipocytes, and this mark is erased in mature adipocytes. H3K27me3 ChIP-seq in brown preadipocytes and mature adipocytes.
