Project description:Brown adipose tissue (BAT) was initially characterised as a thermogenic organ, and recent studies have suggested it plays a crucial role in maintaining systemic metabolic health. In this project, we demonstrated that alteration of BAT function contributes to development of heart failure through disorientation in choline metabolism. To analyze the detail effect of choline accumulation on brown adipocytes, we conducted the LC-QTOF/MS analysis using cultured brown adipocytes treated with d9-choline. In brown adipocytes treated with d9-choline, we found increase of phosphatidylcholine and lysophosphatidylcholine, suggesting that choline was metabolized in healthy brown adipocytes.
Project description:Brown adipocytes are specialized for heat generation and energy expenditure as a defense against cold and obesity. Recent studies demonstrate that brown adipocytes arise in vivo from a Myf5-positive, myoblastic progenitor by the action of PRDM16. Here, we identified a brown fat-enriched miRNA cluster mir-193b-365 as a key regulator of brown fat development. Blocking miR-193b and/or miR-365 in primary brown preadipocytes dramatically impaired brown adipocyte adipogenesis whereas myogenic markers were significantly induced. Forced expression of miR-193b and/or miR-365 in C2C12 myoblasts blocked the entire program of myogenesis, and miR-193b induced myoblasts to differentiate into brown adipocytes. Mir-193b-365 was upregulated by PRDM16. Our results demonstrate that mir-193b-365 serves as an essential regulator for brown fat differentiation, in part by repressing myogenesis. To study if miR-193b-365 is required for brown adipocyte adipogenesis, mRNAs from cultured primary brown adipocytes (Day 4) transfected with each locked nucleic acid (LNA) miRNA inhibitor or Control inhibitor were analyzed by microarray analysis.
Project description:To identify RNAs interacting with lncRNA Gas5 in hippocampal neurons, we performed a Gas5 pulldown from mouse hippocampal cultures using a biotinylated Gas5 bait and performed total and small RNA sequencing
Project description:The adipose organ, including white and brown adipose tissues, is an important player in systemic energy homeostasis, storing excess energy in form of lipids while releasing energy upon various energy demands. Recent studies have demonstrated that white and brown adipocytes also function as endocrine cells and regulate systemic metabolism by secreting factors that act locally and systemically. However, a comparative proteomic analysis of secreted factors from white and brown adipocytes and their responsiveness to adrenergic stimulation has not been reported yet. Therefore, we studied and compared the secretome of white and brown adipocytes, with and without norepinephrine (NE) stimulation. Our results reveal that in the absence of NE, carbohydrate metabolism-regulating proteins are preferably secreted from white adipocytes, while brown adipocytes predominantly secrete integrin signaling proteins. Upon NE stimulation, white adipocytes secrete more proteins involved in lipid metabolism, while brown adipocytes secrete more proteins with specific anti-inflammatory properties. In conclusion, our study provides a comprehensive catalogue of novel adipokine candidates secreted from white and brown adipocytes with many of them responsive to NE.
Project description:Secreted proteins from adipose tissue play a role in metabolic cross-talk and homeostasis. We performed high sensitivity mass spectrometry-based proteomics on the cell media of human adipocytes derived from the supraclavicular brown adipose and from the subcutaneous white adipose depots of adult humans. We identified 471 potentially secreted proteins covering interesting protein categories such as hormones, growth factors, extracellular matrix proteins and proteins of the complement system, which were differentially regulated in brown and white adipocytes. A total of 101 proteins were exclusively quantified in brown adipocytes and among these were ependymin-related protein 1 (EPDR1). Functional studies suggested a role for EPDR1 in thermogenic adipogenesis. In conclusion, we report substantial differences between the secretomes of brown and white human adipocytes and identify novel candidate batokines that can be important regulators of metabolism.
Project description:Brown adipocytes are specialized for heat generation and energy expenditure as a defense against cold and obesity. Recent studies demonstrate that brown adipocytes arise in vivo from a Myf5-positive, myoblastic progenitor by the action of PRDM16. Here, we identified a brown fat-enriched miRNA cluster mir-193b-365 as a key regulator of brown fat development. Blocking miR-193b and/or miR-365 in primary brown preadipocytes dramatically impaired brown adipocyte adipogenesis whereas myogenic markers were significantly induced. Forced expression of miR-193b and/or miR-365 in C2C12 myoblasts blocked the entire program of myogenesis, and miR-193b induced myoblasts to differentiate into brown adipocytes. Mir-193b-365 was upregulated by PRDM16. Our results demonstrate that mir-193b-365 serves as an essential regulator for brown fat differentiation, in part by repressing myogenesis.
Project description:Brown adipose tissue is a specialized fat tissue involved in heat generation by using a process termed thermogenesis. This ability to convert nutrient energy into heat sets brown adipocytes apart from the more common type of white adipocytes, which are mainly involved in energy storage. Brown adipose depots occur as a large interscapular depot in mice. Brown adipocytes are multilocular, i.e. contain many small lipid-filled vacuoles and uniquely express the uncoupling protein 1. In this study, the gene expression patterns in brown adipose tissue samples of young, healthy mice was analyzed.
Project description:We found that overexpression of HOXC4 in mature adipocytes enhances thermogenesis . To investigate the binding sites of HOXC4 in the genome of brown adipocytes, we performed HOXC4 ChIP-seq experiments on differentiated adipocytes derived from interscapular brown adipose tissue, which overexpressed HA-HOXC4.
Project description:Brown adipose tissue (BAT) dissipates energy and promotes cardio-metabolic health4. However, loss of BAT during obesity and aging is a principal hurdle for BAT-centered obesity therapies. So far not much is known about BAT apoptosis and signals released by apoptotic brown adipocytes. Here, untargeted metabolomics demonstrated that apoptotic brown adipocytes release a specific pattern of metabolites with purine metabolites being highly enriched. Interestingly, this apoptotic secretome enhances expression of the thermogenic program in healthy adipocytes to maintain tissue functionality. This effect is mediated by the purine inosine which stimulates energy expenditure (EE) in brown adipocytes. Phosphoproteomic analysis demonstrated activation of the cAMP/protein kinase A signaling pathway and of pro-thermogenic transcription factors by inosine.