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1.
J Clin Invest ; 133(21)2023 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-37909330

RESUMEN

Interplay between energy-storing white adipose cells and thermogenic beige adipocytes contributes to obesity and insulin resistance. Irrespective of specialized niche, adipocytes require the activity of the nuclear receptor PPARγ for proper function. Exposure to cold or adrenergic signaling enriches thermogenic cells though multiple pathways that act synergistically with PPARγ; however, the molecular mechanisms by which PPARγ licenses white adipose tissue to preferentially adopt a thermogenic or white adipose fate in response to dietary cues or thermoneutral conditions are not fully elucidated. Here, we show that a PPARγ/long noncoding RNA (lncRNA) axis integrates canonical and noncanonical thermogenesis to restrain white adipose tissue heat dissipation during thermoneutrality and diet-induced obesity. Pharmacologic inhibition or genetic deletion of the lncRNA Lexis enhances uncoupling protein 1-dependent (UCP1-dependent) and -independent thermogenesis. Adipose-specific deletion of Lexis counteracted diet-induced obesity, improved insulin sensitivity, and enhanced energy expenditure. Single-nuclei transcriptomics revealed that Lexis regulates a distinct population of thermogenic adipocytes. We systematically map Lexis motif preferences and show that it regulates the thermogenic program through the activity of the metabolic GWAS gene and WNT modulator TCF7L2. Collectively, our studies uncover a new mode of crosstalk between PPARγ and WNT that preserves white adipose tissue plasticity.


Asunto(s)
Resistencia a la Insulina , ARN Largo no Codificante , Animales , Ratones , Adipocitos/metabolismo , Tejido Adiposo Pardo/metabolismo , Tejido Adiposo Blanco/metabolismo , Resistencia a la Insulina/genética , Obesidad/genética , Obesidad/metabolismo , PPAR gamma/genética , PPAR gamma/metabolismo , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Termogénesis/genética , Proteína Desacopladora 1/genética
2.
bioRxiv ; 2023 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-38014350

RESUMEN

Scientific evidence underscores the influence of biological sex on the interplay between stress and metabolic dysfunctions. However, there is limited understanding of how diet and stress jointly contribute to metabolic dysregulation in both males and females. To address this gap, our study aimed to investigate the combined effects of a high-fat diet (HFD) and repeated footshock stress on fear-related behaviors and metabolic outcomes in male and female mice. Using a robust rodent model that recapitulates key aspects of post-traumatic stress disorder (PTSD), we subjected mice to footshock stressor followed by weekly reminder footshock stressor or no stressor for 14 weeks while on either an HFD or chow diet. Our findings revealed that HFD impaired fear memory extinction in male mice that received initial stressor but not in female mice. Blood glucose levels were influenced by both diet and sex, with HFD-fed female mice displaying elevated levels that returned to baseline in the absence of stress, a pattern not observed in male mice. Male mice on HFD exhibited higher energy expenditure, while HFD-fed female mice showed a decreased respiratory exchange ratio (RER). Sex-specific alterations in pro-inflammatory markers and abundance of hematopoietic stem cells were observed in chronically stressed mice on an HFD in different peripheral tissues, indicating the manifestation of distinct comorbid disorders. Single-nuclei RNA sequencing of the ventromedial hypothalamus from stressed mice on an HFD provided insights into sex-specific glial cell activation and cell-type-specific transcriptomic changes. In conclusion, our study offers a comprehensive understanding of the intricate interactions between stress, diet, sex, and various physiological and behavioral outcomes, shedding light on a potential brain region coordinating these interactions.

3.
Curr Opin Genet Dev ; 83: 102114, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37738733

RESUMEN

White adipose tissue stores fatty acid (FA) as triglyceride in the lipid droplet organelle of highly specialized cells known as fat cells or adipocytes. Depending on the nutritional state and energy demand, hormonal and biochemical signals converge on activating an elegant and fundamental process known as lipolysis, which involves triglyceride hydrolysis to FAs. Almost six decades of work have vastly expanded our knowledge of lipolysis from enzymatic processes to complex protein assembly, disassembly, and post-translational modification. Research in recent decades ushered in the discovery of new lipolytic enzymes and coregulators and the characterization of numerous factors and signaling pathways that regulate lipid hydrolysis on transcriptional and post-transcriptional levels. This review will discuss recent developments with particular emphasis on the past two years in enzymatic lipolytic pathways and transcriptional regulation of lipolysis. We will summarize the positive and negative regulators of lipolysis, the adipose tissue microenvironment in lipolysis, and the systemic effects of lipolysis. The dynamic nature of adipocyte lipolysis is emerging as an essential regulator of metabolism and energy balance, and we will discuss recent developments in this area.


Asunto(s)
Metabolismo de los Lípidos , Lipólisis , Lipólisis/genética , Metabolismo de los Lípidos/genética , Tejido Adiposo , Adipocitos/metabolismo , Triglicéridos/metabolismo , Triglicéridos/farmacología
4.
Nature ; 620(7972): 192-199, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37495690

RESUMEN

Sympathetic activation during cold exposure increases adipocyte thermogenesis via the expression of mitochondrial protein uncoupling protein 1 (UCP1)1. The propensity of adipocytes to express UCP1 is under a critical influence of the adipose microenvironment and varies between sexes and among various fat depots2-7. Here we report that mammary gland ductal epithelial cells in the adipose niche regulate cold-induced adipocyte UCP1 expression in female mouse subcutaneous white adipose tissue (scWAT). Single-cell RNA sequencing shows that glandular luminal epithelium subtypes express transcripts that encode secretory factors controlling adipocyte UCP1 expression under cold conditions. We term these luminal epithelium secretory factors 'mammokines'. Using 3D visualization of whole-tissue immunofluorescence, we reveal sympathetic nerve-ductal contact points. We show that mammary ducts activated by sympathetic nerves limit adipocyte UCP1 expression via the mammokine lipocalin 2. In vivo and ex vivo ablation of mammary duct epithelium enhance the cold-induced adipocyte thermogenic gene programme in scWAT. Since the mammary duct network extends throughout most of the scWAT in female mice, females show markedly less scWAT UCP1 expression, fat oxidation, energy expenditure and subcutaneous fat mass loss compared with male mice, implicating sex-specific roles of mammokines in adipose thermogenesis. These results reveal a role of sympathetic nerve-activated glandular epithelium in adipocyte UCP1 expression and suggest that mammary duct luminal epithelium has an important role in controlling glandular adiposity.


Asunto(s)
Adipocitos , Tejido Adiposo Blanco , Epitelio , Glándulas Mamarias Animales , Termogénesis , Animales , Femenino , Masculino , Ratones , Adipocitos/metabolismo , Tejido Adiposo Blanco/citología , Tejido Adiposo Blanco/metabolismo , Epitelio/inervación , Epitelio/metabolismo , Proteína Desacopladora 1/genética , Proteína Desacopladora 1/metabolismo , Glándulas Mamarias Animales/citología , Glándulas Mamarias Animales/inervación , Glándulas Mamarias Animales/fisiología , Frío , Sistema Nervioso Simpático/fisiología , Metabolismo Energético , Oxidación-Reducción , Caracteres Sexuales
5.
Genome Med ; 15(1): 30, 2023 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-37127706

RESUMEN

BACKGROUND: Single-cell RNA sequencing (scRNA-seq) provides valuable insights into human islet cell types and their corresponding stable gene expression profiles. However, this approach requires cell dissociation that complicates its utility in vivo. On the other hand, single-nucleus RNA sequencing (snRNA-seq) has compatibility with frozen samples, elimination of dissociation-induced transcriptional stress responses, and affords enhanced information from intronic sequences that can be leveraged to identify pre-mRNA transcripts. METHODS: We obtained nuclear preparations from fresh human islet cells and generated snRNA-seq datasets. We compared these datasets to scRNA-seq output obtained from human islet cells from the same donor. We employed snRNA-seq to obtain the transcriptomic profile of human islets engrafted in immunodeficient mice. In both analyses, we included the intronic reads in the snRNA-seq data with the GRCh38-2020-A library. RESULTS: First, snRNA-seq analysis shows that the top four differentially and selectively expressed genes in human islet endocrine cells in vitro and in vivo are not the canonical genes but a new set of non-canonical gene markers including ZNF385D, TRPM3, LRFN2, PLUT (ß-cells); PTPRT, FAP, PDK4, LOXL4 (α-cells); LRFN5, ADARB2, ERBB4, KCNT2 (δ-cells); and CACNA2D3, THSD7A, CNTNAP5, RBFOX3 (γ-cells). Second, by integrating information from scRNA-seq and snRNA-seq of human islet cells, we distinguish three ß-cell sub-clusters: an INS pre-mRNA cluster (ß3), an intermediate INS mRNA cluster (ß2), and an INS mRNA-rich cluster (ß1). These display distinct gene expression patterns representing different biological dynamic states both in vitro and in vivo. Interestingly, the INS mRNA-rich cluster (ß1) becomes the predominant sub-cluster in vivo. CONCLUSIONS: In summary, snRNA-seq and pre-mRNA analysis of human islet cells can accurately identify human islet cell populations, subpopulations, and their dynamic transcriptome profile in vivo.


Asunto(s)
Islotes Pancreáticos , Transcriptoma , Humanos , Ratones , Animales , Perfilación de la Expresión Génica , Precursores del ARN/metabolismo , Islotes Pancreáticos/metabolismo , Análisis de Secuencia de ARN , ARN Nuclear Pequeño/metabolismo , ARN Mensajero/metabolismo , Análisis de la Célula Individual , Canales de potasio activados por Sodio/genética , Canales de potasio activados por Sodio/metabolismo , Proteína-Lisina 6-Oxidasa/genética , Proteína-Lisina 6-Oxidasa/metabolismo , Glicoproteínas de Membrana/genética , Proteínas del Tejido Nervioso/genética
6.
Genes Dev ; 36(21-24): 1129-1144, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36522129

RESUMEN

GATA4 is a transcription factor known for its crucial role in the development of many tissues, including the liver; however, its role in adult liver metabolism is unknown. Here, using high-throughput sequencing technologies, we identified GATA4 as a transcriptional regulator of metabolism in the liver. GATA4 expression is elevated in response to refeeding, and its occupancy is increased at enhancers of genes linked to fatty acid and lipoprotein metabolism. Knocking out GATA4 in the adult liver (Gata4LKO) decreased transcriptional activity at GATA4 binding sites, especially during feeding. Gata4LKO mice have reduced plasma HDL cholesterol and increased liver triglyceride levels. The expression of a panel of GATA4 binding genes involved in hepatic cholesterol export and triglyceride hydrolysis was down-regulated in Gata4LKO mice. We further demonstrate that GATA4 collaborates with LXR nuclear receptors in the liver. GATA4 and LXRs share a number of binding sites, and GATA4 was required for the full transcriptional response to LXR activation. Collectively, these results show that hepatic GATA4 contributes to the transcriptional control of hepatic and systemic lipid homeostasis.


Asunto(s)
Hígado , Receptores Nucleares Huérfanos , Ratones , Animales , Receptores Nucleares Huérfanos/metabolismo , Receptores X del Hígado/genética , Receptores X del Hígado/metabolismo , Hígado/metabolismo , Homeostasis/genética , Colesterol , Triglicéridos/metabolismo , Metabolismo de los Lípidos , Ratones Endogámicos C57BL , Factor de Transcripción GATA4/genética , Factor de Transcripción GATA4/metabolismo
8.
Front Behav Neurosci ; 16: 995573, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36275856

RESUMEN

Severe stress leads to alterations in energy metabolism with sexually dimorphic onset or severity. The locus coeruleus (LC) in the brainstem that mediates fight-or-flight-or-freeze response to stress is sexually dimorphic in morphology, plays a key role in interactions between diet and severe stressors, and has neuronal input to the brown adipose tissue (BAT)-a thermogenic organ important for energy balance. Yet, little is known on how LC coordinates stress-related metabolic adaptations. LC expresses receptors for the neuropeptide PACAP (pituitary adenylate cyclase activating peptide) and PACAP signaling through PAC1 (PACAP receptor) are critical regulators of various types of stressors and energy metabolism. We hypothesized that LC-PAC1 axis is a sex-specific central "gatekeeper" of severe acute stress-driven behavior and energy metabolism. Selective ablation of PAC1 receptors from the LC did not alter stress response in mice of either sex, but enhanced food intake in females and was associated with increased energy expenditure and BAT thermogenesis in male mice. These results show a sexually dimorphic role of the LC-PAC1 in regulating acute stress-related energy metabolism. Thus, by disrupting LC-PAC1 signaling, our studies show a unique and previously unexplored role of LC in adaptive energy metabolism in a sex-dependent manner.

10.
Sci Rep ; 11(1): 16409, 2021 08 12.
Artículo en Inglés | MEDLINE | ID: mdl-34385484

RESUMEN

We recently showed that NOTUM, a liver-secreted Wnt inhibitor, can acutely promote browning of white adipose. We now report studies of chronic overexpression of NOTUM in liver indicating that it protects against diet-induced obesity and improves glucose homeostasis in mice. Adeno-associated virus (AAV) vectors were used to overexpress GFP or mouse Notum in the livers of male C57BL/6J mice and the mice were fed an obesifying diet. After 14 weeks of high fat, high sucrose diet feeding, the AAV-Notum mice exhibited decreased obesity and improved glucose tolerance compared to the AAV-GFP mice. Gene expression and immunoblotting analysis of the inguinal fat and brown fat revealed increased expression of beige/brown adipocyte markers in the AAV-Notum group, suggesting enhanced thermogenic capacity by NOTUM. A ß3 adrenergic receptor agonist-stimulated lipolysis test suggested increased lipolysis capacity by NOTUM. The levels of collagen and C-C motif chemokine ligand 2 (CCL2) in the epididymal white adipose tissue of the AAV-Notum mice were significantly reduced, suggesting decreased fibrosis and inflammation, respectively. RNA sequencing analysis of inguinal white adipose of 4-week chow diet-fed mice revealed a highly significant enrichment of extracellular matrix (ECM) functional cluster among the down-regulated genes in the AAV-Notum group, suggesting a potential mechanism contributing to improved glucose homeostasis. Our in vitro studies demonstrated that recombinant human NOTUM protein blocked the inhibitory effects of WNT3A on brown adipocyte differentiation. Furthermore, NOTUM attenuated WNT3A's effects on upregulation of TGF-ß signaling and its downstream targets. Overall, our data suggest that NOTUM modulates adipose tissue function by promoting thermogenic capacity and inhibiting fibrosis through inhibition of Wnt signaling.


Asunto(s)
Dieta Alta en Grasa/efectos adversos , Esterasas/metabolismo , Obesidad/metabolismo , Termogénesis/fisiología , Adipocitos Beige/metabolismo , Tejido Adiposo Pardo/metabolismo , Tejido Adiposo Blanco/metabolismo , Animales , Metabolismo Energético/fisiología , Intolerancia a la Glucosa/metabolismo , Lipólisis/fisiología , Masculino , Ratones , Ratones Endogámicos C57BL
11.
Sci Transl Med ; 12(555)2020 08 05.
Artículo en Inglés | MEDLINE | ID: mdl-32759275

RESUMEN

Obesity is heightened during aging, and although the estrogen receptor α (ERα) has been implicated in the prevention of obesity, its molecular actions in adipocytes remain inadequately understood. Here, we show that adipose tissue ESR1/Esr1 expression inversely associated with adiposity and positively associated with genes involved in mitochondrial metabolism and markers of metabolic health in 700 Finnish men and 100 strains of inbred mice from the UCLA Hybrid Mouse Diversity Panel. To determine the anti-obesity actions of ERα in fat, we selectively deleted Esr1 from white and brown adipocytes in mice. In white adipose tissue, Esr1 controlled oxidative metabolism by restraining the targeted elimination of mitochondria via the E3 ubiquitin ligase parkin. mtDNA content was elevated, and adipose tissue mass was reduced in adipose-selective parkin knockout mice. In brown fat centrally involved in body temperature maintenance, Esr1 was requisite for both mitochondrial remodeling by dynamin-related protein 1 (Drp1) and uncoupled respiration thermogenesis by uncoupled protein 1 (Ucp1). In both white and brown fat of female mice and adipocytes in culture, mitochondrial dysfunction in the context of Esr1 deletion was paralleled by a reduction in the expression of the mtDNA polymerase γ subunit Polg1 We identified Polg1 as an ERα target gene by showing that ERα binds the Polg1 promoter to control its expression in 3T3L1 adipocytes. These findings support strategies leveraging ERα action on mitochondrial function in adipocytes to combat obesity and metabolic dysfunction.


Asunto(s)
Adipocitos Marrones , Receptor alfa de Estrógeno , Adipocitos Marrones/metabolismo , Adipocitos Blancos/metabolismo , Tejido Adiposo Pardo/metabolismo , Animales , Receptor alfa de Estrógeno/genética , Receptor alfa de Estrógeno/metabolismo , Femenino , Ratones , Mitocondrias/metabolismo , Proteínas Mitocondriales/metabolismo , Termogénesis , Proteína Desacopladora 1/genética , Proteína Desacopladora 1/metabolismo
12.
J Hepatol ; 73(2): 361-370, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32135178

RESUMEN

BACKGROUND & AIMS: Obesity is a well-established risk factor for type 2 diabetes (T2D) and non-alcoholic steatohepatitis (NASH), but the underlying mechanisms remain incompletely understood. Herein, we aimed to identify novel pathogenic factors (and possible therapeutic targets) underlying metabolic dysfunction in the liver. METHODS: We applied a tandem quantitative proteomics strategy to enrich and identify transcription factors (TFs) induced in the obese liver. We used flow cytometry of liver cells to analyze the source of the induced TFs. We employed conditional knockout mice, shRNA, and small-molecule inhibitors to test the metabolic consequences of the induction of identified TFs. Finally, we validated mouse data in patient liver biopsies. RESULTS: We identified PU.1/SPI1, the master hematopoietic regulator, as one of the most upregulated TFs in livers from diet-induced obese (DIO) and genetically obese (db/db) mice. Targeting PU.1 in the whole liver, but not hepatocytes alone, significantly improved glucose homeostasis and suppressed liver inflammation. Consistently, treatment with the PU.1 inhibitor DB1976 markedly reduced inflammation and improved glucose homeostasis and dyslipidemia in DIO mice, and strongly suppressed glucose intolerance, liver steatosis, inflammation, and fibrosis in a dietary NASH mouse model. Furthermore, hepatic PU.1 expression was positively correlated with insulin resistance and inflammation in liver biopsies from patients. CONCLUSIONS: These data suggest that the elevated hematopoietic factor PU.1 promotes liver metabolic dysfunction, and may be a useful therapeutic target for obesity, insulin resistance/T2D, and NASH. LAY SUMMARY: Expression of the immune regulator PU.1 is increased in livers of obese mice and people. Blocking PU.1 improved glucose homeostasis, and reduced liver steatosis, inflammation and fibrosis in mouse models of non-alcoholic steatohepatitis. Inhibition of PU.1 is thus a potential therapeutic strategy for treating obesity-associated liver dysfunction and metabolic diseases.


Asunto(s)
Ratones Obesos/metabolismo , Enfermedad del Hígado Graso no Alcohólico , Proteínas Proto-Oncogénicas , Transactivadores , Animales , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Dieta Alta en Grasa , Hepatocitos/metabolismo , Humanos , Hígado/patología , Ratones , Ratones Noqueados , Terapia Molecular Dirigida , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Obesidad/tratamiento farmacológico , Obesidad/metabolismo , Proteínas Proto-Oncogénicas/antagonistas & inhibidores , Proteínas Proto-Oncogénicas/metabolismo , ARN Interferente Pequeño/metabolismo , Transactivadores/antagonistas & inhibidores , Transactivadores/metabolismo , Factores de Transcripción/antagonistas & inhibidores , Factores de Transcripción/metabolismo , Regulación hacia Arriba
13.
Elife ; 82019 10 23.
Artículo en Inglés | MEDLINE | ID: mdl-31644425

RESUMEN

Immune cells are vital constituents of the adipose microenvironment that influence both local and systemic lipid metabolism. Mice lacking IL10 have enhanced thermogenesis, but the roles of specific cell types in the metabolic response to IL10 remain to be defined. We demonstrate here that selective loss of IL10 receptor α in adipocytes recapitulates the beneficial effects of global IL10 deletion, and that local crosstalk between IL10-producing immune cells and adipocytes is a determinant of thermogenesis and systemic energy balance. Single Nuclei Adipocyte RNA-sequencing (SNAP-seq) of subcutaneous adipose tissue defined a metabolically-active mature adipocyte subtype characterized by robust expression of genes involved in thermogenesis whose transcriptome was selectively responsive to IL10Rα deletion. Furthermore, single-cell transcriptomic analysis of adipose stromal populations identified lymphocytes as a key source of IL10 production in response to thermogenic stimuli. These findings implicate adaptive immune cell-adipocyte communication in the maintenance of adipose subtype identity and function.


Asunto(s)
Adipocitos/efectos de los fármacos , Comunicación Celular , Regulación de la Expresión Génica , Subunidad alfa del Receptor de Interleucina-10/metabolismo , Interleucina-10/metabolismo , Linfocitos/metabolismo , Termogénesis , Adipocitos/fisiología , Animales , Ratones , Análisis de la Célula Individual , Transcripción Genética
14.
Genes Dev ; 33(13-14): 747-762, 2019 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-31123067

RESUMEN

Prolonged cold exposure stimulates the recruitment of beige adipocytes within white adipose tissue. Beige adipocytes depend on mitochondrial oxidative phosphorylation to drive thermogenesis. The transcriptional mechanisms that promote remodeling in adipose tissue during the cold are not well understood. Here we demonstrate that the transcriptional coregulator transducin-like enhancer of split 3 (TLE3) inhibits mitochondrial gene expression in beige adipocytes. Conditional deletion of TLE3 in adipocytes promotes mitochondrial oxidative metabolism and increases energy expenditure, thereby improving glucose control. Using chromatin immunoprecipitation and deep sequencing, we found that TLE3 occupies distal enhancers in proximity to nuclear-encoded mitochondrial genes and that many of these binding sites are also enriched for early B-cell factor (EBF) transcription factors. TLE3 interacts with EBF2 and blocks its ability to promote the thermogenic transcriptional program. Collectively, these studies demonstrate that TLE3 regulates thermogenic gene expression in beige adipocytes through inhibition of EBF2 transcriptional activity. Inhibition of TLE3 may provide a novel therapeutic approach for obesity and diabetes.


Asunto(s)
Adipocitos Beige/metabolismo , Proteínas Co-Represoras/genética , Proteínas Co-Represoras/metabolismo , Glucosa/metabolismo , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Células Cultivadas , Dieta Alta en Grasa , Metabolismo Energético/genética , Eliminación de Gen , Regulación de la Expresión Génica/genética , Estudio de Asociación del Genoma Completo , Resistencia a la Insulina/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Mitocondrias/genética , Mitocondrias/metabolismo , Termogénesis/genética
15.
Mol Metab ; 25: 50-63, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-31027994

RESUMEN

OBJECTIVE: Obesity has increased to pandemic levels and enhanced understanding of adipose regulation is required for new treatment strategies. Although bone morphogenetic proteins (BMPs) influence adipogenesis, the effect of BMP antagonists such as Noggin is largely unknown. The aim of the study was to define the role of Noggin, an extracellular BMP inhibitor, in adipogenesis. METHODS: We generated adipose-derived progenitor cells and a mouse model with adipocyte-specific Noggin deletion using the AdiponectinCre transgenic mouse, and determined the adipose phenotype of Noggin-deficiency. RESULTS: Our studies showed that Noggin is expressed in progenitor cells but declines in adipocytes, possibly allowing for lipid accumulation. Correspondingly, adipocyte-specific Noggin deletion in vivo promoted age-related obesity in both genders with no change in food intake. Although the loss of Noggin caused white adipose tissue hypertrophy, and whitening and impaired function in brown adipose tissue in both genders, there were clear gender differences with the females being most affected. The females had suppressed expression of brown adipose markers and thermogenic genes including peroxisome proliferator activated receptor gamma coactivator 1 alpha (PGC1alpha) and uncoupling protein 1 (UCP1) as well as genes associated with adipogenesis and lipid metabolism. The males, on the other hand, had early changes in a few BAT markers and thermogenic genes, but the main changes were in the genes associated with adipogenesis and lipid metabolism. Further characterization revealed that both genders had reductions in VO2, VCO2, and RER, whereas females also had reduced heat production. Noggin was also reduced in diet-induced obesity in inbred mice consistent with the obesity phenotype of the Noggin-deficient mice. CONCLUSIONS: BMP signaling regulates female and male adipogenesis through different metabolic pathways. Modulation of adipose tissue metabolism by select BMP antagonists may be a strategy for long-term regulation of age-related weight gain and obesity.


Asunto(s)
Adipocitos/metabolismo , Adipogénesis/fisiología , Proteínas Morfogenéticas Óseas/metabolismo , Proteínas Portadoras/metabolismo , Obesidad/metabolismo , Adipocitos/patología , Adipogénesis/genética , Tejido Adiposo/metabolismo , Tejido Adiposo Pardo/metabolismo , Tejido Adiposo Blanco/metabolismo , Animales , Proteínas Morfogenéticas Óseas/efectos de los fármacos , Proteínas Portadoras/genética , Modelos Animales de Enfermedad , Ingestión de Alimentos , Femenino , Eliminación de Gen , Regulación de la Expresión Génica , Estudios de Asociación Genética , Producto de la Acumulación de Lípidos , Metabolismo de los Lípidos , Masculino , Ratones , Ratones Obesos , Ratones Transgénicos , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma/genética , Transducción de Señal/genética , Termogénesis/genética , Termogénesis/fisiología , Transcriptoma , Proteína Desacopladora 1/genética
16.
Nat Metab ; 1(11): 1089-1100, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-32072135

RESUMEN

Liver X receptors limit cellular lipid uptake by stimulating the transcription of Inducible Degrader of the LDL Receptor (IDOL), an E3 ubiquitin ligase that targets lipoprotein receptors for degradation. The function of IDOL in systemic metabolism is incompletely understood. Here we show that loss of IDOL in mice protects against the development of diet-induced obesity and metabolic dysfunction by altering food intake and thermogenesis. Unexpectedly, analysis of tissue-specific knockout mice revealed that IDOL affects energy balance, not through its actions in peripheral metabolic tissues (liver, adipose, endothelium, intestine, skeletal muscle), but by controlling lipoprotein receptor abundance in neurons. Single-cell RNA sequencing of the hypothalamus demonstrated that IDOL deletion altered gene expression linked to control of metabolism. Finally, we identify VLDLR rather than LDLR as the primary mediator of IDOL effects on energy balance. These studies identify a role for the neuronal IDOL-VLDLR pathway in metabolic homeostasis and diet-induced obesity.


Asunto(s)
Metabolismo Energético/fisiología , Neuronas/metabolismo , Receptores de LDL/metabolismo , Ubiquitina-Proteína Ligasas/fisiología , Animales , Glucemia/metabolismo , Dieta , Metabolismo Energético/genética , Hipotálamo/metabolismo , Resistencia a la Insulina , Ratones , Ratones Noqueados , Obesidad/metabolismo , Obesidad/prevención & control , Ubiquitina-Proteína Ligasas/genética
17.
Cell Metab ; 27(5): 1138-1155.e6, 2018 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-29719227

RESUMEN

Inter-tissue communication via secreted proteins has been established as a vital mechanism for proper physiologic homeostasis. Here, we report a bioinformatics framework using a mouse reference population, the Hybrid Mouse Diversity Panel (HMDP), which integrates global multi-tissue expression data and publicly available resources to identify and functionally annotate novel circuits of tissue-tissue communication. We validate this method by showing that we can identify known as well as novel endocrine factors responsible for communication between tissues. We further show the utility of this approach by identification and mechanistic characterization of two new endocrine factors. Adipose-derived Lipocalin-5 is shown to enhance skeletal muscle mitochondrial function, and liver-secreted Notum promotes browning of white adipose tissue, also known as "beiging." We demonstrate the general applicability of the method by providing in vivo evidence for three additional novel molecules mediating tissue-tissue interactions.


Asunto(s)
Sistema Endocrino/metabolismo , Homeostasis , Lipocalinas/metabolismo , Proteómica/métodos , Tejido Adiposo/metabolismo , Animales , Células Cultivadas , Ratones , Ratones Endogámicos C57BL , Mitocondrias/metabolismo , Proteínas Mitocondriales/metabolismo , Músculo Esquelético/metabolismo
18.
Nat Med ; 24(3): 304-312, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29431742

RESUMEN

Nuclear receptors regulate gene expression in response to environmental cues, but the molecular events governing the cell type specificity of nuclear receptors remain poorly understood. Here we outline a role for a long noncoding RNA (lncRNA) in modulating the cell type-specific actions of liver X receptors (LXRs), sterol-activated nuclear receptors that regulate the expression of genes involved in cholesterol homeostasis and that have been causally linked to the pathogenesis of atherosclerosis. We identify the lncRNA MeXis as an amplifier of LXR-dependent transcription of the gene Abca1, which is critical for regulation of cholesterol efflux. Mice lacking the MeXis gene show reduced Abca1 expression in a tissue-selective manner. Furthermore, loss of MeXis in mouse bone marrow cells alters chromosome architecture at the Abca1 locus, impairs cellular responses to cholesterol overload, and accelerates the development of atherosclerosis. Mechanistic studies reveal that MeXis interacts with and guides promoter binding of the transcriptional coactivator DDX17. The identification of MeXis as a lncRNA modulator of LXR-dependent gene expression expands understanding of the mechanisms underlying cell type-selective actions of nuclear receptors in physiology and disease.


Asunto(s)
Aterosclerosis/genética , Colesterol/metabolismo , ARN Helicasas DEAD-box/genética , Receptores X del Hígado/genética , ARN Largo no Codificante/genética , Transportador 1 de Casete de Unión a ATP/genética , Animales , Células de la Médula Ósea/metabolismo , Colesterol/genética , Regulación de la Expresión Génica/genética , Humanos , Receptores X del Hígado/metabolismo , Macrófagos/metabolismo , Ratones , Regiones Promotoras Genéticas , Transcripción Genética
19.
J Biol Chem ; 293(13): 4735-4751, 2018 03 30.
Artículo en Inglés | MEDLINE | ID: mdl-29378845

RESUMEN

Estrogen receptor α (ERα) action plays an important role in pancreatic ß-cell function and survival; thus, it is considered a potential therapeutic target for the treatment of type 2 diabetes in women. However, the mechanisms underlying the protective effects of ERα remain unclear. Because ERα regulates mitochondrial metabolism in other cell types, we hypothesized that ERα may act to preserve insulin secretion and promote ß-cell survival by regulating mitochondrial-endoplasmic reticulum (EndoRetic) function. We tested this hypothesis using pancreatic islet-specific ERα knockout (PERαKO) mice and Min6 ß-cells in culture with Esr1 knockdown (KD). We found that Esr1-KD promoted reactive oxygen species production that associated with reduced fission/fusion dynamics and impaired mitophagy. Electron microscopy showed mitochondrial enlargement and a pro-fusion phenotype. Mitochondrial cristae and endoplasmic reticulum were dilated in Esr1-KD compared with ERα replete Min6 ß-cells. Increased expression of Oma1 and Chop was paralleled by increased oxygen consumption and apoptosis susceptibility in ERα-KD cells. In contrast, ERα overexpression and ligand activation reduced both Chop and Oma1 expression, likely by ERα binding to consensus estrogen-response element sites in the Oma1 and Chop promoters. Together, our findings suggest that ERα promotes ß-cell survival and insulin secretion through maintenance of mitochondrial fission/fusion-mitophagy dynamics and EndoRetic function, in part by Oma1 and Chop repression.


Asunto(s)
Apoptosis , Estrés del Retículo Endoplásmico , Receptor alfa de Estrógeno/metabolismo , Células Secretoras de Insulina/metabolismo , Mitocondrias/metabolismo , Mitofagia , Animales , Supervivencia Celular , Receptor alfa de Estrógeno/genética , Femenino , Insulina/genética , Insulina/metabolismo , Metaloproteasas/biosíntesis , Metaloproteasas/genética , Ratones , Ratones Noqueados , Mitocondrias/genética , Proteínas Mitocondriales/biosíntesis , Proteínas Mitocondriales/genética , Especies Reactivas de Oxígeno/metabolismo , Factor de Transcripción CHOP/biosíntesis , Factor de Transcripción CHOP/genética
20.
Cell ; 172(1-2): 218-233.e17, 2018 01 11.
Artículo en Inglés | MEDLINE | ID: mdl-29249357

RESUMEN

Signaling pathways that promote adipose tissue thermogenesis are well characterized, but the limiters of energy expenditure are largely unknown. Here, we show that ablation of the anti-inflammatory cytokine IL-10 improves insulin sensitivity, protects against diet-induced obesity, and elicits the browning of white adipose tissue. Mechanistic studies define bone marrow cells as the source of the IL-10 signal and adipocytes as the target cell type mediating these effects. IL-10 receptor alpha is highly enriched in mature adipocytes and is induced in response to differentiation, obesity, and aging. Assay for transposase-accessible chromatin sequencing (ATAC-seq), ChIP-seq, and RNA-seq reveal that IL-10 represses the transcription of thermogenic genes in adipocytes by altering chromatin accessibility and inhibiting ATF and C/EBPß recruitment to key enhancer regions. These findings expand our understanding of the relationship between inflammatory signaling pathways and adipose tissue function and provide insight into the physiological control of thermogenesis that could inform future therapy.


Asunto(s)
Adipocitos/metabolismo , Ensamble y Desensamble de Cromatina , Metabolismo Energético , Interleucina-10/metabolismo , Termogénesis , Factores de Transcripción Activadores/metabolismo , Animales , Proteína beta Potenciadora de Unión a CCAAT/metabolismo , Línea Celular , Células Cultivadas , Interleucina-10/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Transducción de Señal
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