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:Obesity and type 2 diabetes cause a loss in brown adipose tissue (BAT) activity in mice and human, but the molecular mechanisms that drive BAT cell remodeling remain largely. Using a multilayered approach, we comprehensively map a deep reorganization in the BAT cells. We uncovered a subset of macrophages as the lipid-associated macrophages (LAM), which were massively increased in genetic and dietary model of BAT expansion. LAM participate in this scenario by capturing extracellular vesicles carrying damaged lipids and mitochondria released from metabolically-stressed brown adipocytes. CD36 scavenger receptor drives LAM phenotype and through * in vitro* and *in vivo* models, we demonstrated that CD36-deficient LAM increased brown fat genes. LAM release Tgfb1 that reduces brown adipocytes identity through Aldh1a1 induction. This study provides the first description of cell dynamics in BAT of obese models identifying LAM as responder to tissue-level metabolic stress and key driver to loss of BAT cell identity.
Project description:Obesity and type 2 diabetes cause a loss in brown adipose tissue (BAT) activity in mice and human, but the molecular mechanisms that drive BAT cell remodeling remain largely. Using a multilayered approach, we comprehensively map a deep reorganization in the BAT cells. We uncovered a subset of macrophages as the lipid-associated macrophages (LAM), which were massively increased in genetic and dietary model of BAT expansion. LAM participate in this scenario by capturing extracellular vesicles carrying damaged lipids and mitochondria released from metabolically-stressed brown adipocytes. CD36 scavenger receptor drives LAM phenotype and through * in vitro* and *in vivo* models, we demonstrated that CD36-deficient LAM increased brown fat genes. LAM release Tgfb1 that reduces brown adipocytes identity through Aldh1a1 induction. This study provides the first description of cell dynamics in BAT of obese models identifying LAM as responder to tissue-level metabolic stress and key driver to loss of BAT cell identity.
Project description:Obesity and type 2 diabetes cause a loss in brown adipose tissue (BAT) activity in mice and human, but the molecular mechanisms that drive BAT cell remodeling remain largely. Using a multilayered approach, we comprehensively map a deep reorganization in the BAT cells. We uncovered a subset of macrophages as the lipid-associated macrophages (LAM), which were massively increased in genetic and dietary model of BAT expansion. LAM participate in this scenario by capturing extracellular vesicles carrying damaged lipids and mitochondria released from metabolically-stressed brown adipocytes. CD36 scavenger receptor drives LAM phenotype and through * in vitro* and *in vivo* models, we demonstrated that CD36-deficient LAM increased brown fat genes. LAM release Tgfb1 that reduces brown adipocytes identity through Aldh1a1 induction. This study provides the first description of cell dynamics in BAT of obese models identifying LAM as responder to tissue-level metabolic stress and key driver to loss of BAT cell identity.
Project description:Obesity and type 2 diabetes cause a loss in brown adipose tissue (BAT) activity in mice and human, but the molecular mechanisms that drive BAT cell remodeling remain largely. Using a multilayered approach, we comprehensively map a deep reorganization in the BAT cells. We uncovered a subset of macrophages as the lipid-associated macrophages (LAM), which were massively increased in genetic and dietary model of BAT expansion. LAM participate in this scenario by capturing extracellular vesicles carrying damaged lipids and mitochondria released from metabolically-stressed brown adipocytes. CD36 scavenger receptor drives LAM phenotype and through * in vitro* and *in vivo* models, we demonstrated that CD36-deficient LAM increased brown fat genes. LAM release Tgfb1 that reduces brown adipocytes identity through Aldh1a1 induction. This study provides the first description of cell dynamics in BAT of obese models identifying LAM as responder to tissue-level metabolic stress and key driver to loss of BAT cell identity.
Project description:Histones were isolated from brown adipose tissue and liver from mice housed at 28, 22, or 8 C. Quantitative top- or middle-down approaches were used to quantitate histone H4 and H3.2 proteoforms. See published article for complimentary RNA-seq and RRBS datasets.
Project description:To analyze the gene expression profile of BAT and gWAT from Pgam1 depletion mice, we performed whole genome microarray expression profiling using brown adipose tissue (BAT) and gonadal white adipose tissue (gWAT) from adipose tissue-specific Pgam1 knockout (KO) mice.
Project description:Brown adipose tissue (BAT) was suggested to play an important role in lipid and glucose metabolism in rodents and possibly also in humans. In the current study, we used genetic and correlation analyses in the BXH/HXB recombinant inbred (RI) strains, derived from Brown Norway (BN) and spontaneously hypertensive rats (SHR), to identify genetic determinants of BAT function and its role in the pathogenesis of metabolic disturbances. Linkage analyses revealed significant quantitative trait locus (QTL) associated with interscapular BAT mass in the vicinity of the Cd36 (fatty acid translocase) gene on chromosome 4. Additional two closely linked QTL asociated with glucose oxidation and incorporation into BAT lipids were detected near the Wars2 (tryptophanyl tRNA synthetase 2, mitochondrial) candidate gene on chromosome 2.
Project description:We performed a genome-wide deep sequencing analysis of the microRNAs abundant in mesenchymal stem cells (MSCs) derived from murine brown adipose tissue and in in vitro differentiated mature brown adipocytes. Several microRNAs were identified as differentially regulated when comparing datasets from MSCs vs. mature fat cells. These microRNAs may have an implication in the regulation of adipogenesis as well as thermogenesis in brown adipose tissue (BAT). Examination of BAT-derived MSCs (BAT-MSC; 1 sample) and in vitro differentiated mature brown fat cells (BAT-DIFF; 1 sample) vertis biotechnologie AG, D-85354 Freising, Germany (library construction and sequencing)
Project description:m6A mRNA methylation in brown adipose tissue regulates systemic insulin sensitivity. We performed N6-methyladenosine (m6A) profiling and RNA seq of brown adipose tissue (BAT) from control and Mettl14-KO mice. Meanwhile, we performed RNA-seq for control and Mettl14-KO human BAT cell line as well.