Project description:Using high throughput sequencing we report chromatin accessibility(ATAC-seq) and transcriptome profiling (RNA-seq)and in mouse brown adipose tissue (BAT) upon cold exposure in wildtype and Dot1L-BAT specific KO mice.
Project description:Purpose: We investigated the transcriptomic change in brown fat of young and old mice (wild type) through high-throughput RNA-sequencing (RNA-Seq) analysis when the mice were exposed to cold room or room temperatur. Methods: We prepared 10 of young (3 months) mice and 9 of old (24 months) mice, and kept them in cold room (4°c) or room temperature (24°c) for 24 hours. Then, we sacrified mice and extracted RNA from brown fat tissue (BAT) for RNA-seq experiment. Results: BAT of Young mice showed increased carbohydrate metabolism and glycolytic flux during cold exposure Conclusions: The thermogenesis function of BAT is accelerated on cold exposure.
Project description:Regulation of the thermogenic response by brown adipose tissue (BAT) is an important mechanism in the basic biology and treatment of obesity and diabetes. Consensus transcriptional regulatory analysis of a publicly-available RNA-seq dataset uncovered a large number of nodes representing epigenetic modifiers that were altered in BAT in response to chronic thermogenic activation. Thus, we hypothesized that chronic activation of BAT results in epigenetic modifications of DNA and histones that affect the tissue function. To test our hypothesis, wildtype male C57BL/6J mice were housed under chronic conditions of thermoneutral temperature (TN, 28.8°C), mild cold/room temperature (RT, 22°C), or severe cold (SC, 8°C). Reduced representation bisulfite sequencing (RRBS) revealed a marked decrease in methylation of promoters and intragenic regions in BAT genomic DNA in response to varying degrees of chronic cold exposure. Integration of our RRBS and the publicly available RNA-Seq dataset suggested a role for epigenetic modification of DNA in gene regulation in response to cold. To analyze histone modifications, we developed a robust method for the isolation and quantitation of histone proteoforms, which enabled the first comparison of histone H3.2 and H4 proteoforms in BAT. We report distinct on/off histone signals that are observed with histone H3.2 in BAT, but not in the liver, when mice are acclimated to severe cold in comparison with mild cold. Specifically, we observe a larger percentage of histone H3.2 with the K9 dimethylation mark coupled with K36 mono- or di-methylation and K23 acetylation, suggesting strong repression of previously active chromatin. Taken together, our results provide novel findings supporting global epigenetic modification in murine BAT in response to varying degrees of chronic cold stimuli and establish a methodology to quantitatively study histones in BAT, allowing for direct comparisons to decipher mechanistic changes during the thermogenic response.
Project description:oActivationf brown adipose tissue (BAT) has gained central attention due to its known ability to dissipate energy and counteract cardiometabolic diseases (CMDs). The cold exposure on BAT activation and the induction of thermogenesis have been extensively studied, but reports on the effects at the proteomic level in metabolic tissues of animal models mimicking CMD in humans are lacking.
Project description:Regulatory T (Treg) cells are critical determinants of both immune responses and metabolic control. Here we show that systemic ablation of Treg cells compromised the adaptation of whole-body energy expenditure to cold exposure, correlating with impairment in thermogenic marker gene expression and massive invasion of pro-inflammatory macrophages in brown adipose tissue (BAT). Indeed, BAT harbored a unique sub-set of Treg cells characterized by a unique gene signature. As these Treg cells respond to BAT activation upon cold exposure, this study defines a BAT-specific Treg sub-set with direct implications for the regulation of energy homeostasis in response to environmental stress.
Project description:Regulatory T (Treg) cells are critical determinants of both immune responses and metabolic control. Here we show that systemic ablation of Treg cells compromised the adaptation of whole-body energy expenditure to cold exposure, correlating with impairment in thermogenic marker gene expression and massive invasion of pro-inflammatory macrophages in brown adipose tissue (BAT). Indeed, BAT harbored a unique sub-set of Treg cells characterized by a unique gene signature. As these Treg cells respond to BAT activation upon cold exposure, this study defines a BAT-specific Treg sub-set with direct implications for the regulation of energy homeostasis in response to environmental stress. We isolated regulatory and conventional T cells from brown-adipose tissue of warm-conditioned or cold-conditioned mice. As controls, we harvested spleen-Treg and Tconv cells from warm-treated mice. Cells were isolated pooled organs and target cells purified by FACS. RNA was extracted and gene expression measured.
Project description:Recent studies suggest that brown adipose tissue (BAT) plays a role in energy and glucose metabolism in humans. However, the physiological significance of human BAT in lipid metabolism remains unknown. To gain insight regarding the mechanisms of accelerated lipid metabolism in relation to the cold-activated BAT, we performed molecular (transcriptome) profiling of supraclavicular and subcutaneous abdominal adipose tissue samples collected from one subject during CE (cold exposure) and TN (thermoneutral) conditions.
Project description:mRNA expression profiles from interscapular brown adipose (iBAT) tissue male ATF4 BAT KO mice and their WT counterparts after 3 days of cold exposure.
Project description:Brown adipose tissue (BAT) is a thermogenic organ that requires Uncoupling Protein 1 (UCP1) to dissipate chemical energy as heat, to defend core body temperature against hypothermia, and counteract obesity and metabolic diseases1. However, the transcriptional mechanism ensuring BAT thermogenic capacity for survival prior to environmental cold is unknown. Here we show histone deacetylase 3 (HDAC3) is a required transcriptional regulator of BAT enhancers to ensure thermogenic aptitude and survival. Mice with genetic ablation of HDAC3 become severely hypothermic and fail to survive acute cold exposure. UCP1 is nearly absent in BAT lacking HDAC3 and there is marked down-regulation of mitochondrial oxidative phosphorylation (OXPHOS) genes. Remarkably, although HDAC3 canonically functions as a transcriptional corepressor2, HDAC3 functions as a coactivator of the estrogen-related receptor _ (ERR_) in BAT, and loss of HDAC3 leads to robust global down-regulation of ERR±-driven enhancers. HDAC3 coactivation of ERR_ is mediated through deacetylation of PGC-1_ and is required for basal transcription of Ucp1, OXPHOS, and Pgc-1_. Thus, HDAC3 uniquely primes Ucp1 and thermogenic gene transcription to ensure immediate BAT-driven thermogenesis upon acute exposure to dangerously cold temperatures.
Project description:Brown adipose tissue (BAT) is a thermogenic organ that requires Uncoupling Protein 1 (UCP1) to dissipate chemical energy as heat, to defend core body temperature against hypothermia, and counteract obesity and metabolic diseases1. However, the transcriptional mechanism ensuring BAT thermogenic capacity for survival prior to environmental cold is unknown. Here we show histone deacetylase 3 (HDAC3) is a required transcriptional regulator of BAT enhancers to ensure thermogenic aptitude and survival. Mice with genetic ablation of HDAC3 become severely hypothermic and fail to survive acute cold exposure. UCP1 is nearly absent in BAT lacking HDAC3 and there is marked down-regulation of mitochondrial oxidative phosphorylation (OXPHOS) genes. Remarkably, although HDAC3 canonically functions as a transcriptional corepressor2, HDAC3 functions as a coactivator of the estrogen-related receptor _ (ERR_) in BAT, and loss of HDAC3 leads to robust global down-regulation of ERR±-driven enhancers. HDAC3 coactivation of ERR_ is mediated through deacetylation of PGC-1_ and is required for basal transcription of Ucp1, OXPHOS, and Pgc-1_. Thus, HDAC3 uniquely primes Ucp1 and thermogenic gene transcription to ensure immediate BAT-driven thermogenesis upon acute exposure to dangerously cold temperatures.