Histone Deacetylase 3 Prepares Brown Adipose Tissue For Acute Thermogenic Challenge
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE83928 | GEO | 2017/06/14
SECONDARY ACCESSION(S): PRJNA327418
REPOSITORIES: GEO
Similar Datasets
Project description:Brown adipose tissue is a thermogenic organ that dissipates chemical energy as heat to protect animals against hypothermia and to counteract metabolic disease. However, the transcriptional mechanisms that determine the thermogenic capacity of brown adipose tissue before environmental cold are unknown. Here we show that histone deacetylase 3 (HDAC3) is required to activate brown adipose tissue enhancers to ensure thermogenic aptitude. Mice with brown adipose tissue-specific genetic ablation of HDAC3 become severely hypothermic and succumb to acute cold exposure. Uncoupling protein 1 (UCP1) is nearly absent in brown adipose tissue lacking HDAC3, and there is also marked downregulation of mitochondrial oxidative phosphorylation genes resulting in diminished mitochondrial respiration. Remarkably, although HDAC3 acts canonically as a transcriptional corepressor, it functions as a coactivator of oestrogen-related receptor α (ERRα) in brown adipose tissue. HDAC3 coactivation of ERRα is mediated by deacetylation of PGC-1α and is required for the transcription of Ucp1, Ppargc1a (encoding PGC-1α), and oxidative phosphorylation genes. Importantly, HDAC3 promotes the basal transcription of these genes independently of adrenergic stimulation. Thus, HDAC3 uniquely primes Ucp1 and the thermogenic transcriptional program to maintain a critical capacity for thermogenesis in brown adipose tissue that can be rapidly engaged upon exposure to dangerously cold temperature.
| S-EPMC5826652 | biostudies-literature
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.
2017-06-14 | GSE83927 | GEO
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.
2017-06-14 | GSE83926 | GEO
Project description:Histone Deacetylase 3 Prepares Brown Adipose Tissue For Acute Thermogenic Challenge
| PRJNA327418 | ENA
Project description:Mitochondrial fusion and fission events, collectively known as mitochondrial dynamics, act as quality control mechanisms to ensure mitochondrial function and fine-tune cellular bioenergetics. Defective mitofusin 2 (Mfn2) expression and enhanced mitochondrial fission in skeletal muscle are hallmarks of insulin-resistant states. Interestingly, Mfn2 is highly expressed in brown adipose tissue (BAT), yet its role remains unexplored. Using adipose-specific Mfn2 knockout (Mfn2-adKO) mice, we demonstrate that Mfn2, but not Mfn1, deficiency in BAT leads to a profound BAT dysfunction, associated with impaired respiratory capacity and a blunted response to adrenergic stimuli. Importantly, Mfn2 directly interacts with perilipin 1, facilitating the interaction between the mitochondria and the lipid droplet in response to adrenergic stimulation. Surprisingly, Mfn2-adKO mice were protected from high-fat diet-induced insulin resistance and hepatic steatosis. Altogether, these results demonstrate that Mfn2 is a mediator of mitochondria to lipid droplet interactions, influencing lipolytic processes and whole-body energy homeostasis.
| S-EPMC5452040 | biostudies-literature
Project description:The coactivator peroxisome proliferator-activated receptor-gamma coactivator 1 ? (PGC-1?) is widely considered a central transcriptional regulator of adaptive thermogenesis in brown adipose tissue (BAT). However, mice lacking PGC-1? specifically in adipose tissue have only mild thermogenic defects, suggesting the presence of additional regulators. Using the activity of estrogen-related receptors (ERRs), downstream effectors of PGC-1?, as read-out in a high-throughput genome-wide cDNA screen, we identify here growth arrest and DNA-damage-inducible protein 45 ? (GADD45?) as a cold-induced activator of uncoupling protein 1 (UCP1) and oxidative capacity in BAT. Mice lacking Gadd45? have defects in Ucp1 induction and the thermogenic response to cold. GADD45? works by activating MAPK p38, which is a potent activator of ERR? and ERR? transcriptional function. GADD45? activates ERR? independently of PGC-1 coactivators, yet synergizes with PGC-1? to induce the thermogenic program. Our findings elucidate a previously unidentified GADD45?/p38/ERR? pathway that regulates BAT thermogenesis and may enable new approaches for the stimulation of energy expenditure. Our study also implicates GADD45 proteins as general metabolic regulators.
| S-EPMC4136592 | biostudies-literature
Project description:Although many transcriptional pathways regulating BAT have been identified, the role of lipid biosynthetic enzymes in thermogenesis has been less investigated. Whereas cold exposure causes changes in the fatty acid composition of BAT, the functional consequences of this remains relatively unexplored. In this study, we demonstrate that the enzyme Elongation of Very Long Chain fatty acids 6 (Elovl6) is necessary for the thermogenic action of BAT. Elovl6 is responsible for converting C16 non-essential fatty acids into C18 species. Loss of Elovl6 does not modulate traditional BAT markers; instead, it causes reduced expression of mitochondrial electron transport chain components and lower BAT thermogenic capacity. The reduction in BAT activity appears to be counteracted by increased beiging of scWAT. When beige fat is disabled by thermoneutrality or aging, Elovl6 KO mice gain weight and have increased scWAT mass and impaired carbohydrate metabolism. Overall, our study suggests fatty acid chain length is important for BAT function.
| S-EPMC4688035 | biostudies-literature
Project description:Therapeutic increase of brown adipose tissue (BAT) thermogenesis is of great interest as BAT activation counteracts obesity and insulin resistance. Hyaluronan (HA) is a glycosaminoglycan, found in the extracellular matrix, which is synthesized by HA synthases (Has1/Has2/Has3) from sugar precursors and accumulates in diabetic conditions. Its synthesis can be inhibited by the small molecule 4-methylumbelliferone (4-MU). Here, we show that the inhibition of HA-synthesis by 4-MU or genetic deletion of Has2/Has3 improves BAT`s thermogenic capacity, reduces body weight gain, and improves glucose homeostasis independently from adrenergic stimulation in mice on diabetogenic diet, as shown by a magnetic resonance T2 mapping approach. Inhibition of HA synthesis increases glycolysis, BAT respiration and uncoupling protein 1 expression. In addition, we show that 4-MU increases BAT capacity without inducing chronic stimulation and propose that 4-MU, a clinically approved prescription-free drug, could be repurposed to treat obesity and diabetes.
| S-EPMC6786893 | biostudies-literature
Project description:Adipocytes possess remarkable adaptive capacity to respond to nutrient excess, fasting or cold exposure, and they are thus an important cell type for the maintenance of proper metabolic health. Although the endoplasmic reticulum (ER) is a critical organelle for cellular homeostasis, the mechanisms that mediate adaptation of the ER to metabolic challenges in adipocytes are unclear. Here we show that brown adipose tissue (BAT) thermogenic function requires an adaptive increase in proteasomal activity to secure cellular protein quality control, and we identify the ER-localized transcription factor nuclear factor erythroid 2-like 1 (Nfe2l1, also known as Nrf1) as a critical driver of this process. We show that cold adaptation induces Nrf1 in BAT to increase proteasomal activity and that this is crucial for maintaining ER homeostasis and cellular integrity, specifically when the cells are in a state of high thermogenic activity. In mice, under thermogenic conditions, brown-adipocyte-specific deletion of Nfe2l1 (Nrf1) resulted in ER stress, tissue inflammation, markedly diminished mitochondrial function and whitening of the BAT. In mouse models of both genetic and dietary obesity, stimulation of proteasomal activity by exogenously expressing Nrf1 or by treatment with the proteasome activator PA28α in BAT resulted in improved insulin sensitivity. In conclusion, Nrf1 emerges as a novel guardian of brown adipocyte function, providing increased proteometabolic quality control for adapting to cold or to obesity.
| S-EPMC5839993 | biostudies-literature
Project description:Brown adipose tissue (BAT), as the main site of adaptive thermogenesis, exerts beneficial metabolic effects on obesity and insulin resistance. BAT has been previously assumed to contain a homogeneous population of brown adipocytes. Utilizing multiple mouse models capable of genetically labeling different cellular populations, as well as single-cell RNA sequencing and 3D tissue profiling, we discovered a brown adipocyte subpopulation with low thermogenic activity coexisting with the classical high-thermogenic brown adipocytes within the BAT. Compared with the high-thermogenic brown adipocytes, these low-thermogenic brown adipocytes had substantially lower Ucp1 and Adipoq expression, larger lipid droplets, and lower mitochondrial content. Functional analyses showed that, unlike the high-thermogenic brown adipocytes, the low-thermogenic brown adipocytes have markedly lower basal mitochondrial respiration, and they are specialized in fatty acid uptake. Upon changes in environmental temperature, the 2 brown adipocyte subpopulations underwent dynamic interconversions. Cold exposure converted low-thermogenic brown adipocytes into high-thermogenic cells. A thermoneutral environment had the opposite effect. The recruitment of high-thermogenic brown adipocytes by cold stimulation is not affected by high-fat diet feeding, but it does substantially decline with age. Our results revealed a high degree of functional heterogeneity of brown adipocytes.
| S-EPMC6934193 | biostudies-literature