Project description:Purpose: Determine the function of lncBATE10 in brown and white adipocyte differentiation Methods: primary brown and white apreadipocytes were isolated by cell culture. We infected brown preadipocytes with retroviral shRNA targeting lncBATE10 or with retrovirus overexpressing lncBATE10. Cells were induced to differetinate for 5 days. Total RNA were harvested for RNA-seq Conclusions: Our study shows that lncBATE10 is required for BAT-selective program expression. Overexpression of lncBATE10 is not sufficient to promote BAT marker expression.
Project description:Brown adipose tissue (BAT) has in recent times been rediscovered in adult humans, and together with work from preclinical models, shown to have the potential of providing a variety of positive metabolic benefits. These include improved insulin sensitivity and reduced susceptibility to obesity and its various co-morbidities. As such, its continued study could offer insights to therapeutically modulate this tissue to improve metabolic health. It has been reported that adipose-specific deletion of the gene for protein kinase D1 (Prkd1) enhances mitochondrial respiration and improves whole-body glucose homeostasis. We sought to determine whether these effects were mediated specifically through brown adipocytes using a Prkd1 brown adipose tissue (BAT) Ucp1-Cre-specific knockout mouse model, Prkd1BKO. We unexpectedly observed that upon both cold exposure and beta-3-AR agonist administration, Prkd1 loss in BAT did not alter canonical thermogenic gene expression or adipocyte morphology. We took an unbiased approach to assess whether other signaling pathways were altered. RNAs from cold-exposed control and Prkd1BKO were subjected to RNA-Seq analysis. These studies revealed that myogenic gene expression is altered in Prkd1BKO BAT after both acute (8 hr) and extended (4 day) cold exposure. Given that brown adipocytes and skeletal myocytes share a common precursor cell lineage expressing myogenic factor 5 (Myf5), these data suggest that loss of Prkd1 in BAT may alter the biology of preadipocytes in this depot. The data presented herein clarify the role of Prkd1 in BAT thermogenesis and present new avenues for the further study of Prkd1 function in BAT.
Project description:Attainment of a brown adipocyte cell phenotype in white adipocytes, with their abundant mitochondria and increased energy expenditure potential, is a legitimate strategy for combating obesity. The unique transcriptional regulators of the primary brown adipocyte phenotype are unknown, limiting our ability to promote brown adipogenesis over white. In the present work, we used microarray analysis strategies to study primary preadipocytes, and we made the striking discovery that brown preadipocytes demonstrate a myogenic transcriptional signature, whereas both brown and white primary preadipocytes demonstrate signatures distinct from those found in immortalized adipogenic models. We found a plausible SIRT1-related transcriptional signature during brown adipocyte differentiation that may contribute to silencing the myogenic signature. In contrast to brown preadipocytes or skeletal muscle cells, white preadipocytes express Tcf21, a transcription factor that has been shown to suppress myogenesis and nuclear receptor activity. In addition, we identified a number of developmental genes that are differentially expressed between brown and white preadipocytes and that have recently been implicated in human obesity. The interlinkage between the myocyte and the brown preadipocyte confirms the distinct origin for brown versus white adipose tissue and also represents a plausible explanation as to why brown adipocytes ultimately specialize in lipid catabolism rather than storage, much like oxidative skeletal muscle tissue. Experiment Overall Design: Comparisons of white and brown pre- and mature-adiposytes
Project description:Attainment of a brown adipocyte cell phenotype in white adipocytes, with their abundant mitochondria and increased energy expenditure potential, is a legitimate strategy for combating obesity. The unique transcriptional regulators of the primary brown adipocyte phenotype are unknown, limiting our ability to promote brown adipogenesis over white. In the present work, we used microarray analysis strategies to study primary preadipocytes, and we made the striking discovery that brown preadipocytes demonstrate a myogenic transcriptional signature, whereas both brown and white primary preadipocytes demonstrate signatures distinct from those found in immortalized adipogenic models. We found a plausible SIRT1-related transcriptional signature during brown adipocyte differentiation that may contribute to silencing the myogenic signature. In contrast to brown preadipocytes or skeletal muscle cells, white preadipocytes express Tcf21, a transcription factor that has been shown to suppress myogenesis and nuclear receptor activity. In addition, we identified a number of developmental genes that are differentially expressed between brown and white preadipocytes and that have recently been implicated in human obesity. The interlinkage between the myocyte and the brown preadipocyte confirms the distinct origin for brown versus white adipose tissue and also represents a plausible explanation as to why brown adipocytes ultimately specialize in lipid catabolism rather than storage, much like oxidative skeletal muscle tissue. Keywords: In vitro differentiation
Project description:The CCR4-NOT deadenylase complex has a critical function to trigger mRNA decay and various biological events. To understand roles of the complex in adipocyte function, we compare RNA expression between control and Cnot complex-deficient brown and white adipose tissues.
Project description:We report molecular characterization of human brown and white adipocytes. We showed that PAZ6 and SW872 cells exhibit classical molecular and phenotypic markers of brown and white adipocytes, respectively. However, SGBS cells presented a versatile phenotype of adipocyte
Project description:Brown adipose tissue is specialized to burn lipids for heat generation as a natural defense against cold and obesity. Previous studies established microRNAs as essential regulators of brown adipocyte differentiation, but it remains unknown whether microRNAs are required for the feature maintenance of mature brown adipocytes. To address this question, we ablated Dgcr8, a key regulator of the microRNA biogenesis pathway, in mature brown as well as white adipocytes. The adipose tissue -specific Dgcr8 knockout mice displayed enlarged but pale interscapular brown fat with decreased expression of genes characteristic of brown fat, and the mice were intolerant to cold exposure. In vitro primary brown adipocyte cultures confirmed that microRNAs are required for marker gene expression in mature brown adipocytes. We also demonstrated that microRNAs are essential for the browning of subcutaneous white adipocyte both in vitro and in vivo. Using this animal model, we performed microRNA expression profiling analysis and identified a set of BAT-specific microRNAs that are up-regulated during brown adipocyte differentiation and enriched in brown fat compared to other organs. We identified miR-182 and miR-203 as new regulators of brown adipocyte development. Taken together, our study demonstrates an essential role of microRNAs in the maintenance as well as the differentiation of brown adipocytes.
Project description:The experiment was designed to determine the gene expression changes cultured brown adipocytes in response to the inflammatory stimulus of LPS treatment. Both wild type and TLR4 knockout cells were applied to enable assessment of the contribution of TLR4 to the response.