CRISPR/Cas9 inducible UCP1 knockout in brown adipose tissue of adult mice
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE176453 | GEO | 2021/07/01
REPOSITORIES: GEO
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Project description:Non-shivering thermogenesis in adipocytes is mediated by brown adipose tissue, purportedly through the sole action of uncoupling protein 1 (UCP1). The physiological relevance of UCP1-dependent thermogenesis has primarily been inferred from the attenuation of thermogenic output of mice genetically lacking Ucp1 from birth (germline Ucp1-/-). However, germline Ucp1-/- mice harbor secondary changes within brown adipose tissue beyond UCP1, such as reduced electron transport chain abundance. We show here that these secondary changes also encompass reduced expression of genes regulating fuel liberation, changes that would attenuate the capacity of any thermogenic pathway. Therefore, the quantitative contribution of UCP1-dependent and -independent thermogenesis is not fully understood. To mitigate the potentially confounding ancillary changes to brown adipose tissue of germline Ucp1-/- mice, we constructed mice with inducible adipocyte-selective disruption of Ucp1. We find that, while germline Ucp1-/- mice succumb to cold-induced hypothermia with complete penetrance, most mice with inducible deletion of Ucp1 maintain homeothermy in the cold. However, inducible adipocyte-selective co-deletion of Ucp1 and creatine kinase B (Ckb, an effector of UCP1-independent thermogenesis) exacerbates cold-intolerance, indicative of a negative genetic interaction and thus a parallel thermogenic function. We find no evidence for impairments in insulation or non-shivering thermogenesis in skeletal muscle that would drive this phenotype. Furthermore, following UCP1 deletion or UCP1/CKB co-deletion from mature adipocytes, moderate cold exposure triggers the regeneration of mature adipocytes that coordinately restore UCP1 and CKB to brown adipose tissue, providing further evidence of their parallel thermogenic relationship. Our findings suggest that thermogenic adipocytes utilize non-paralogous protein redundancy – through UCP1 and CKB – to promote cold-induced energy dissipation.
2024-01-10 | PXD047841 | Pride
Project description:Abstract
Brown and brite adipocytes are the key cells performing uncoupling protein 1 (UCP1) dependent non-shivering thermogenesis (NST) induced by cold exposure. Several lipid species are associated to NST in brown and white adipose tissue. Studies investigating the association of the lipid profile with NST rely on the analysis of whole organ homogenates or on the differentiation of pre-adipocytes in vitro. These approaches have so far not addressed the heterogeneity of white adipose tissue. Aim of this study was to characterize the lipid composition of white adipose tissue on a region-specific level in an in vivo context.
We applied MALDI mass spectrometry imaging (MALDI-MSI) in combination with immunohistochemistry and high-resolution mass spectrometry on sections of inguinal white adipose tissue of 129S6/SvEvTac and C57BL6/N-UCP1 knockout and wildtype mice acclimatized to cold to identify lipids specific to areas of UCP1 expression.
Based on the analysis of cold exposed 129S6/SvEvTac mice we identified cardiolipins (CL) and diacylglycerols (DG) species to be specific for areas expressing UCP1 and triacylglycerols (TG) to be the main lipid class characteristic for UCP1 negative regions within inguinal white adipose tissue. Investigation of C57BL6/N-UCP1 knockout and wildtype mice housed at either room temperature or acclimatized to cold, demonstrated that CL content in white adipose tissue is increased upon cold stimulation, independent of UCP1.
We introduce a MALDI-MSI based approach to identify lipids associated to thermogenic adipocytes in adipose tissues demonstrating a clear regional cold dependent upregulation of CL independent of UCP1.
2021-04-07 | MSV000087164 | MassIVE
Project description:CRISPR/Cas9 inducible UCP1 knockout in brown adipose tissue of adult mice
| PRJNA736319 | ENA
Project description:Since brown adipose tissue (BAT) dissipates energy through UCP1, BAT has garnered attention as a therapeutic intervention for obesity and metabolic diseases including type 2 diabetes. As we better understand the roles of classical brown and beige adipocytes, increased beige fat mass in response to a variety of external/internal cues is associated with significant improvements in glucose and lipid homeostasis that may not be entirely mediated by UCP1. We aim to analyze transcriptome of wild type and UCP1-null beige adipocyte to identify the UCP1-independent function.
2017-10-28 | E-MTAB-4085 | biostudies-arrayexpress
Project description:We analyzed coding transcript abundance in fully differentiated, primary brown adipocytes from murine, interscapular brown adipose tissue of wildtype and UCP1-KO mice.
2018-09-13 | GSE119873 | GEO
Project description:We analyzed coding transcript abundance in murine, interscapular brown adipose tissue from wildtype and UCP1-KO mice.
2018-11-06 | GSE122133 | GEO
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.
2018-07-12 | PXD009262 | Pride
Project description:Differentiation of brown adipocytes is a crucial process for adaptive thermogenesis, which is stimulated by various factors. We found robust browning of inguinal white adipose tissue in UCP1/ApoE-DKO mice, but not in ApoE-KO mice, under high-fat diet condition. We used microarray to determine the genes specifically regulated in the browning white adipose tissue in UCP1/ApoE-DKO mice.
2018-10-01 | GSE95273 | GEO
Project description:Interest in human brown fat as a novel therapeutic target to tackle the growing obesity and diabetes epidemic has increased dramatically in recent years. While much insight into brown fat biology has been gained from murine cell lines and models, few resources are available to study human brown fat in-vitro. In this study, we detail the derivation and characterization of a novel human ES UCP1 reporter cell line that marks UCP1 positive adipocytes in-vitro. We targeted a mCherry reporter to the UCP1 stop codon via CRISPR-Cas9 and demonstrated that when differentiated to brown adipocytes, reporter cells express UCP1, display high mitochondrial content and multi-locular lipid morphology, and exhibit functional properties such as lipolysis in the presence of isoproterenol and forskolin. Isolation and purification of mCherry positive cells demonstrated elevated expression of brown fat marker genes and a high similarity to isolated human brown fat versus white fat via RNA-seq. This reporter cell line thus presents new opportunities to study human brown fat biology by enabling future work to understand early human brown fat development, performing disease modeling, and enabling drug screening applications.
2020-07-27 | GSE109163 | GEO
Project description:Non-alcoholic fatty liver disease (NAFLD) is the most prevalent liver pathology worldwide and is intimately linked with obesity and type 2 diabetes. Liver inflammation is a hallmark of NAFLD and is thought to contribute to tissue fibrosis and disease pathogenesis. Uncoupling protein 1 (UCP1) is exclusively expressed in brown and beige adipocytes and has been extensively studied for its capacity to elevate thermogenesis and reverse obesity. Here we identify an endocrine pathway regulated by UCP1 that antagonizes liver inflammation and pathology, independent of effects on obesity. We show that, without UCP1, brown and beige fat exhibit a diminished capacity to clear succinate from the circulation. Moreover, UCP1KO mice exhibit elevated extracellular succinate in liver tissue that drives inflammation through ligation of its cognate receptor succinate receptor 1 (SUCNR1) in liver-resident stellate cell and macrophage populations. Conversely, increasing brown and beige adipocyte content in mice antagonizes SUCNR1-dependent inflammatory signaling in the liver. We show that this UCP1-succinate-SUCNR1 axis is necessary to regulate liver immune cell infiltration and pathology, and systemic glucose intolerance in an obesogenic environment. As such, the therapeutic utility of brown and beige adipocytes, and UCP1, extends beyond thermogenesis and may be leveraged to antagonize NAFLD and SUCNR1-dependent liver inflammation.
2022-02-17 | PXD024717 | Pride