Project description:PGE2/EP3 signaling and m6A modification is required for brown adipocyte differentiation and BAT development, but the underlying mechanisms involved remain to be elucidated. The Arraystar mousen M6a-MRNA&lncRNA Epitranscriptomic microarray analysis was performed on mouse brown preadipocytes with or without EP3 deletion.
Project description:By conducting CUT&TAG, we reported that brown adipogenesis induction markedly increased ZFP410 occupancy on chromatin. GO analysis revealed that genes containing the ZFP410-bound peaks were enriched in fat cell differentiation. Consistently, binding signals of ZFP410 on the promoter regions of CHD4 as well as brown genes such as Pgc-1a, Prdm16 and Cyto C were markedly increased in differentiated pre-adipocytes compared to those in control cells.
Project description:Brown adipose tissue plays a crucial role in modulating whole-body energy expenditure through the thermogenic function of its mitochondrial respiratory chain. Pharmacological interventions targeting this function hold significant therapeutic promise. Thus, gaining a comprehensive understanding of the pathophysiological regulation of brown adipose tissue is imperative for future therapeutic applications. In this study, we investigated the metabolic mechanisms underlying the regulation of mature brown adipocyte function by the mitochondrial respiratory chain. Our findings indicate that deficiency in mitochondrial complex I in mature brown adipocytes leads to lipidomic remodeling. This remodeling results in an increase in arachidonic acid content and prostaglandin E2 (PGE2) production, leading to reduced transcriptional activity of peroxisome proliferator-activated receptor gamma (PPARγ) and peroxisome proliferator-activated receptor alpha (PPARα) and alterations in the content of PPAR activator complexes, which consequently result in reduced brown adipocyte thermogenesis and peroxisomal gene expression in mature brown adipocyte. In summary, our study elucidates that the mitochondrial-derived arachidonic acid signal regulates brown adipocyte thermogenesis and peroxisome biogenesis by modulating the PPAR activator complex."
Project description:Gene expression profile from brown adipose tissues of Prdm16 knockout and wile type mice. Prdm16 is a transcription factor that regulates the thermogenic gene program in brown and beige adipocytes. However, whether Prdm16 is required for the development or physiological function of brown adipose tissue (BAT) in vivo has been unclear. By analyzing mice that selectively lacked Prdm16 in the brown adipose lineage, we found that Prdm16 was dispensable for embryonic BAT development.
Project description:Various physiological stimuli, such as cold environment, diet, and hormones, trigger brown adipose tissue (BAT) to produce heat through sympathetic nervous system (SNS)- and -adrenergic receptors (ARs). The AR stimulation increases intracellular cAMP levels through heterotrimeric G proteins and adenylate cyclases, but the processes by which cAMP modulates brown adipocyte function are not fully understood. Here we described that specific ablation of cAMP production in brown adipocytes led to reduced lipolysis, mitochondrial biogenesis, uncoupling protein 1 (Ucp1) expression, and consequently defective adaptive thermogenesis. Elevated cAMP signaling by sympathetic activation inhibited Salt-inducible kinase 2 (Sik2) through protein kinase A (PKA)-mediated phosphorylation in brown adipose tissue. Inhibition of SIKs enhanced Ucp1 expression in differentiated brown adipocytes and Sik2 knockout mice exhibited enhanced adaptive thermogenesis at thermoneutrality in an Ucp1-dependent manner. Taken together, our data indicate that suppressing Sik2 by PKA-mediated phosphorylation is a requisite for SNS-induced Ucp1 expression and adaptive thermogenesis in BAT, and targeting Sik2 may present a novel therapeutic strategy to ramp up BAT thermogenic activity in humans.
Project description:Gene expression profile from brown adipose tissues of Prdm16 knockout and wile type mice. Prdm16 is a transcription factor that regulates the thermogenic gene program in brown and beige adipocytes. However, whether Prdm16 is required for the development or physiological function of brown adipose tissue (BAT) in vivo has been unclear. By analyzing mice that selectively lacked Prdm16 in the brown adipose lineage, we found that Prdm16 was dispensable for embryonic BAT development. Brown adipose tissues were collected from Prdm16 knockout and wiletype mice with 4 biological replicates per condition. Experiment was done in two separate batch for 6-week-old and 11-month-old. Extracted RNA was hybridized to Agilent two-color arrays.
Project description:Active thermogenic adipocytes voraciously consume energy substrates like fatty acids and glucose to maintain body temperature upon cold exposure. Despite strong evidence for the involvement of brown adipose tissue (BAT) in controlling systemic energy homeostasis upon nutrient excess, it is unclear how the activity of brown adipocytes is regulated in times of nutrient scarcity. Therefore, this study aimed to scrutinize factors that modulate BAT activity to balance thermogenic and energetic needs upon simultaneous fasting and cold-exposure. For an unbiased view we performed transcriptomic and miRNA sequencing analysis of BAT from acutely fasted (24 hours) mice under mild cold exposure. Combining these data with in-depth bioinformatic analyses and in vitro experiments, we defined a previously undescribed axis of p53 and miR-92a-1-5p that is highly upregulated by fasting in thermogenic adipocytes. p53, a fasting-responsive transcription factor, was previously shown to control genes involved in the thermogenic program and miR-92a-1-5p was found to negatively correlate with human BAT activity. Here, we elucidated fructose transporter Slc2a5 as one direct downstream target of this axis and show that fructose can be taken up by and metabolized in brown adipocytes. In sum, this study delineates a fasting-induced pathway involving p53 and miR-92a-1-5p impinging on Slc2a5 and suggests a contribution of fructose as an energy substrate in thermogenic adipocytes.
Project description:Brown and beige adipose tissue are emerging as distinct endocrine organs. These tissues are functionally associated with skeletal muscle, adipose tissue metabolism and systemic energy expenditure, suggesting an interorgan signaling network. Using metabolomics, we identify 3-methyl-2-oxovaleric acid, 5-oxoproline, and β-hydroxyisobutyric acid as small molecule metabokines synthesized in browning adipocytes and secreted via monocarboxylate transporters. 3-methyl-2-oxovaleric acid, 5-oxoproline and β-hydroxyisobutyric acid induce a brown adipocyte-specific phenotype in white adipocytes and mitochondrial oxidative energy metabolism in skeletal myocytes both in vitro and in vivo. 3-methyl-2-oxovaleric acid and 5-oxoproline signal through cAMP-PKA-p38 MAPK and β-hydroxyisobutyric acid via mTOR. In humans, plasma and adipose tissue 3-methyl-2-oxovaleric acid, 5-oxoproline and β-hydroxyisobutyric acid concentrations correlate with markers of adipose browning and inversely associate with body mass index. These metabolites reduce adiposity, increase energy expenditure and improve glucose and insulin homeostasis in mouse models of obesity and diabetes. Our findings identify beige adipose-brown adipose-muscle physiological metabokine crosstalk.