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1.
Proc Natl Acad Sci U S A ; 120(33): e2305717120, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37549287

RESUMO

Great progress has been made in identifying positive regulators that activate adipocyte thermogenesis, but negative regulatory signaling of thermogenesis remains poorly understood. Here, we found that cardiotrophin-like cytokine factor 1 (CLCF1) signaling led to loss of brown fat identity, which impaired thermogenic capacity. CLCF1 levels decreased during thermogenic stimulation but were considerably increased in obesity. Adipocyte-specific CLCF1 transgenic (CLCF1-ATG) mice showed impaired energy expenditure and severe cold intolerance. Elevated CLCF1 triggered whitening of brown adipose tissue by suppressing mitochondrial biogenesis. Mechanistically, CLCF1 bound and activated ciliary neurotrophic factor receptor (CNTFR) and augmented signal transducer and activator of transcription 3 (STAT3) signaling. STAT3 transcriptionally inhibited both peroxisome proliferator-activated receptor-γ coactivator (PGC) 1α and 1ß, which thereafter restrained mitochondrial biogenesis in adipocytes. Inhibition of CNTFR or STAT3 could diminish the inhibitory effects of CLCF1 on mitochondrial biogenesis and thermogenesis. As a result, CLCF1-TG mice were predisposed to develop metabolic dysfunction even without external metabolic stress. Our findings revealed a brake signal on nonshivering thermogenesis and suggested that targeting this pathway could be used to restore brown fat activity and systemic metabolic homeostasis in obesity.


Assuntos
Adipócitos Marrons , Biogênese de Organelas , Animais , Camundongos , Adipócitos Marrons/metabolismo , Tecido Adiposo Marrom/metabolismo , Homeostase , Obesidade/genética , Obesidade/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Termogênese/fisiologia
2.
EMBO J ; 40(24): e108069, 2021 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-34704268

RESUMO

Brown and beige fat are specialized for energy expenditure by dissipating energy from glucose and fatty acid oxidation as heat. While glucose and fatty acid metabolism have been extensively studied in thermogenic adipose tissues, the involvement of amino acids in regulating adaptive thermogenesis remains little studied. Here, we report that asparagine supplementation in brown and beige adipocytes drastically upregulated the thermogenic transcriptional program and lipogenic gene expression, so that asparagine-fed mice showed better cold tolerance. In mice with diet-induced obesity, the asparagine-fed group was more responsive to ß3-adrenergic receptor agonists, manifesting in blunted body weight gain and improved glucose tolerance. Metabolomics and 13 C-glucose flux analysis revealed that asparagine supplement spurred glycolysis to fuel thermogenesis and lipogenesis in adipocytes. Mechanistically, asparagine stimulated the mTORC1 pathway, which promoted expression of thermogenic genes and key enzymes in glycolysis. These findings show that asparagine bioavailability affects glycolytic and thermogenic activities in adipose tissues, providing a possible nutritional strategy for improving systemic energy homeostasis.


Assuntos
Asparagina/farmacologia , Glicólise/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Termogênese/efeitos dos fármacos , Animais , Células Cultivadas , Temperatura Baixa , Regulação da Expressão Gênica/efeitos dos fármacos , Masculino , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Metabolômica , Camundongos
3.
Cell ; 137(1): 73-86, 2009 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-19345188

RESUMO

Brown fat is specialized for energy expenditure, a process that is principally controlled by the transcriptional coactivator PGC-1alpha. Here, we describe a molecular network important for PGC-1alpha function and brown fat metabolism. We find that twist-1 is selectively expressed in adipose tissue, interacts with PGC-1alpha, and is recruited to the promoters of PGC-1alpha's target genes to suppress mitochondrial metabolism and uncoupling. In vivo, transgenic mice expressing twist-1 in the adipose tissue are prone to high-fat-diet-induced obesity, whereas twist-1 heterozygous knockout mice are obesity resistant. These phenotypes are attributed to their altered mitochondrial metabolism in the brown fat. Interestingly, the nuclear receptor PPARdelta not only mediates the actions of PGC-1alpha but also regulates twist-1 expression, suggesting a negative-feedback regulatory mechanism. These findings reveal an unexpected physiological role for twist-1 in the maintenance of energy homeostasis and have important implications for understanding metabolic control and metabolic diseases.


Assuntos
Tecido Adiposo Marrom/metabolismo , Proteínas Nucleares/metabolismo , Transativadores/genética , Proteína 1 Relacionada a Twist/metabolismo , Adipócitos/metabolismo , Tecido Adiposo Marrom/citologia , Animais , Metabolismo Energético , Histonas/metabolismo , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Mitocôndrias/metabolismo , Obesidade/metabolismo , PPAR delta/genética , PPAR delta/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Transativadores/metabolismo , Fatores de Transcrição
4.
Proc Natl Acad Sci U S A ; 117(36): 22413-22422, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32839323

RESUMO

Brown and beige adipocytes harbor the thermogenic capacity to adapt to environmental thermal or nutritional changes. Histone methylation is an essential epigenetic modification involved in the modulation of nonshivering thermogenesis in adipocytes. Here, we describe a molecular network leading by KMT5c, a H4K20 methyltransferase, that regulates adipocyte thermogenesis and systemic energy expenditure. The expression of Kmt5c is dramatically induced by a ß3-adrenergic signaling cascade in both brown and beige fat cells. Depleting Kmt5c in adipocytes in vivo leads to a decreased expression of thermogenic genes in both brown and subcutaneous (s.c.) fat tissues. These mice are prone to high-fat-diet-induced obesity and develop glucose intolerance. Enhanced transformation related protein 53 (Trp53) expression in Kmt5c knockout (KO) mice, that is due to the decreased repressive mark H4K20me3 on its proximal promoter, is responsible for the metabolic phenotypes. Together, these findings reveal the physiological role for KMT5c-mediated H4K20 methylation in the maintenance and activation of the thermogenic program in adipocytes.


Assuntos
Adipócitos Bege/fisiologia , Adipócitos Marrons/fisiologia , Histona-Lisina N-Metiltransferase , Termogênese/fisiologia , Proteína Supressora de Tumor p53/metabolismo , Adipócitos Bege/metabolismo , Adipócitos Marrons/metabolismo , Animais , Dieta Hiperlipídica , Feminino , Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo , Masculino , Camundongos , Camundongos Knockout , Proteína Supressora de Tumor p53/genética
5.
Hepatology ; 74(4): 1864-1883, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33934381

RESUMO

BACKGROUND AND AIMS: NAFLD, characterized by aberrant triglyceride accumulation in liver, affects the metabolic remodeling of hepatic and nonhepatic tissues by secreting altered hepatokines. Small ubiquitin-related modifier (SUMO)-specific protease 2 (SENP2) is responsible for de-SUMOylation of target protein, with broad effects on cell growth, signal transduction, and developmental processes. However, the role of SENP2 in hepatic metabolism remains unclear. APPROACH AND RESULTS: We found that SENP2 was the most dramatically increased SENP in the fatty liver and that its level was modulated by fed/fasted conditions. To define the role of hepatic SENP2 in metabolic regulation, we generated liver-specific SENP2 knockout (Senp2-LKO) mice. Senp2-LKO mice exhibited resistance to high-fat diet-induced hepatic steatosis and obesity. RNA-sequencing analysis showed that Senp2 deficiency up-regulated genes involved in fatty acid oxidation and down-regulated genes in lipogenesis in the liver. Additionally, ablation of hepatic SENP2 activated thermogenesis of adipose tissues. Improved energy homeostasis of both the liver and adipose tissues by SENP2 disruption prompted us to detect the hepatokines, with FGF21 identified as a key factor markedly elevated in Senp2-LKO mice that maintained metabolic homeostasis. Loss of FGF21 obviously reversed the positive effects of SENP2 deficiency on metabolism. Mechanistically, by screening transcriptional factors of FGF21, peroxisome proliferator-activated receptor alpha (PPARα) was defined as the mediator for SENP2 and FGF21. SENP2 interacted with PPARα and deSUMOylated it, thereby promoting ubiquitylation and subsequent degradation of PPARα, which in turn inhibited FGF21 expression and fatty acid oxidation. Consistently, SENP2 overexpression in liver facilitated development of metabolic disorders. CONCLUSIONS: Our finding demonstrated a key role of hepatic SENP2 in governing metabolic balance by regulating liver-adipose tissue crosstalk, linking the SUMOylation process to metabolic regulation.


Assuntos
Tecido Adiposo/metabolismo , Cisteína Endopeptidases/genética , Fatores de Crescimento de Fibroblastos/metabolismo , Fígado/metabolismo , Hepatopatia Gordurosa não Alcoólica/genética , PPAR alfa/metabolismo , Animais , Cisteína Endopeptidases/metabolismo , Dieta Hiperlipídica , Metabolismo Energético/genética , Ácidos Graxos/metabolismo , Fígado Gorduroso/genética , Fígado Gorduroso/metabolismo , Humanos , Lipogênese/genética , Síndrome Metabólica/genética , Síndrome Metabólica/metabolismo , Camundongos , Camundongos Knockout , Hepatopatia Gordurosa não Alcoólica/metabolismo , Obesidade/genética , Obesidade/metabolismo , Sumoilação , Termogênese/genética , Ubiquitinação
6.
Yi Chuan ; 44(10): 867-880, 2022 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-36384724

RESUMO

The activation of brown adipose tissues and beige adipose tissues can utilize more substrates, including glucose and fatty acids, regulate the energy balance of the whole body and improve metabolic diseases such as obesity and type Ⅱ diabetes. Elucidating the regulatory mechanisms underlying the thermogenic adipose program may provide excellent targets for therapeutics against metabolic diseases. The current studies have indicated that epigenetic modifications are vital for regulating differentiation and thermogenesis of adipose tissues. In this review, we summarize the recent progress of epigenetic modifications in adipose tissue development and thermogenesis from the aspects of DNA methylation, histone modification, chromatin remodeling, and non-coding RNAs in order to provide new ideas for further studying the activation of adipose tissues.


Assuntos
Diabetes Mellitus Tipo 2 , Doenças Metabólicas , Humanos , Epigênese Genética , Termogênese/genética , Tecido Adiposo Marrom/metabolismo , Doenças Metabólicas/metabolismo
7.
Biochem Biophys Res Commun ; 501(1): 273-279, 2018 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-29730295

RESUMO

Brown adipose tissue (BAT) is specialized for energy expenditure, but the signaling pathways that regulate BAT metabolism and activity are incompletely understood. Interferon (IFN) signaling is a sophisticated defense mechanism to counteract viral infection. IFNs and interferon-stimulated genes (ISGs) are reported to exert profound effects on adipocytes. IFN-α inducible protein 27 (Ifi27/ISG12a) is a BAT-enriched gene, yet no any studies on its roles in BAT have been reported. Here, we show that Ifi27 protein localizes to mitochondria and the expression of Ifi27 can be induced by ß3-adrenergic activation in adipose tissues. Knockdown of Ifi27 leads to reduced expression of key enzymes of tricarboxylic acid cycle (TCA), the subunits of electron transport chain (ETC) and uncoupling protein 1 (Ucp1) in brown and beige adipocytes. Moreover, the browning of subcutaneous white fat induced by ß3-adrenergic agonist is also dramatically blocked. Ectopic expression of Ifi27 in brown adipocytes has the opposite effects. Together, these data indicate that Ifi27 regulates mitochondrial function and browning in adipocytes.


Assuntos
Adipócitos Marrons/metabolismo , Mitocôndrias/metabolismo , Proteínas/metabolismo , Adipócitos Marrons/citologia , Tecido Adiposo Marrom/citologia , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/citologia , Tecido Adiposo Branco/metabolismo , Animais , Diferenciação Celular , Ciclo do Ácido Cítrico , Transporte de Elétrons , Metabolismo Energético , Técnicas de Silenciamento de Genes , Interferon-alfa/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , PPAR delta/metabolismo , Proteínas/antagonistas & inibidores , Proteínas/genética , Transdução de Sinais , Termogênese , Proteína Desacopladora 1/metabolismo
8.
PLoS Genet ; 8(6): e1002761, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22719268

RESUMO

Hepatic gluconeogenesis is required for maintaining blood glucose homeostasis; yet, in diabetes mellitus, this process is unrestrained and is a major contributor to fasting hyperglycemia. To date, the impacts of chromatin modifying enzymes and chromatin landscape on gluconeogenesis are poorly understood. Through catalyzing the removal of methyl groups from specific lysine residues in the histone tail, histone demethylases modulate chromatin structure and, hence, gene expression. Here we perform an RNA interference screen against the known histone demethylases and identify a histone H3 lysine 36 (H3K36) demethylase, Jhdm1a, as a key negative regulator of gluconeogenic gene expression. In vivo, silencing of Jhdm1a promotes liver glucose synthesis, while its exogenous expression reduces blood glucose level. Importantly, the regulation of gluconeogenesis by Jhdm1a requires its demethylation activity. Mechanistically, we find that Jhdm1a regulates the expression of a major gluconeogenic regulator, C/EBPα. This is achieved, at least in part, by its USF1-dependent association with the C/EBPα promoter and its subsequent demethylation of dimethylated H3K36 on the C/EBPα locus. Our work provides compelling evidence that links histone demethylation to transcriptional regulation of gluconeogenesis and has important implications for the treatment of diabetes.


Assuntos
Glicemia , Gluconeogênese , Histona Desmetilases com o Domínio Jumonji , Fígado/metabolismo , Animais , Glicemia/metabolismo , Proteínas Estimuladoras de Ligação a CCAAT/genética , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Células Cultivadas , Regulação da Expressão Gênica , Gluconeogênese/genética , Glucose-6-Fosfatase/metabolismo , Hepatócitos/metabolismo , Humanos , Histona Desmetilases com o Domínio Jumonji/genética , Histona Desmetilases com o Domínio Jumonji/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Serina-Treonina Quinases/metabolismo , RNA Interferente Pequeno/genética , Ratos , Fatores Estimuladores Upstream/metabolismo
9.
Sci Total Environ ; 912: 169064, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38052392

RESUMO

The role of upflow velocity and Ca2+ concentration in controlling the type and rate of CaCO3 crystallization and their impacts on the anaerobic granular sludge (AnGS) formation and performance in an expanded granular sludge bed (EGSB) reactor were studied. The results showed that an improved upflow velocity could promote metastable CaCO3 crystals and achieve the optimized portion of vaterite with a value of 84 % at 10 m/h with a small amount of aragonite, thus limiting the scaling in the reactor. The removal efficiency of Ca2+ was to some extent positively correlated to the influent Ca2+ concentration, but declined when Ca2+ exceeded a specific threshold. Vaterite was dominant with the increase of Ca2+ concentrations of the influent. Compared with granules in R1 (Ca2+ 10 mg/L) and R2 (Ca2+ 100 mg/L), granules cultivated in R3 (Ca2+ 800 mg/L) revealed maximum amount of biomass with biggest particle size distribution and fastest average settling rate, with relative stable COD removal efficiency and the fast optimized reactor capacity at OLR of 16 kgCOD/m3d. A low upflow velocity and a higher Ca2+ concentration promoted nucleus formation and granules growth at the initial cultivation stage of the EGSB reactor. The Ca2+ concentration had a significant impact on the bacterial community and favoured the growth of Tolumonas and Anaeromousa Anaeroarcus. Archaea, rather than bacteria, was strengthened to contribute more to methane production at a relatively high Ca2+ concentration.


Assuntos
Esgotos , Águas Residuárias , Esgotos/microbiologia , Cálcio , Eliminação de Resíduos Líquidos/métodos , Anaerobiose , Cristalização , Reatores Biológicos , Bactérias , Carbonato de Cálcio
10.
iScience ; 26(10): 108091, 2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37860762

RESUMO

Y-box binding protein 2 (YBX2) is an essential modulator of brown adipose tissue activation, yet the regulation on its own expression and the involved mechanism remains largely unknown. Herein, we report the YBX2 protein level, but not mRNA level, is induced in response to acute ß-adrenergic signaling. In this context, YBX2 is a dual substrate for both AMPK and Akt2. The phosphorylation at Thr115 by AMPK or at Ser137 by Akt2 facilitates YBX2 accumulation in brown adipocytes by decreasing ubiquitination-mediated degradation. Beyond stabilizing PGC1α mRNA, increased YBX2 upon thermogenic activation assists the expression of glycolytic enzymes, promotes glucose utilization and lactate production. Mechanistically, YBX2 modulates translation of glycolytic genes via direct binding to 5'-UTRs of these genes. Together these findings suggest YBX2 is responsive to thermogenic stimuli by phosphorylation modification, and stabilized YBX2 helps to boost glycolysis and thermogenesis in brown adipocytes.

11.
bioRxiv ; 2023 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-37745491

RESUMO

The endocrine control of food intake remains incompletely understood, and whether the leptin receptor-mediated anorexigenic pathway in the hypothalamus is negatively regulated by a humoral factor is unknown. Here we identify an appetite-stimulating factor - ASRA - that acts as a leptin receptor antagonist. ASRA encodes an 8 kD protein that is abundantly and selectively expressed in adipose tissue and to a lesser extent, in liver, and is upregulated during fasting and cold. ASRA protein associates with autophagosomes and its secretion is induced by energy deficiency. Overexpression of ASRA in mice attenuates leptin receptor signaling leading to elevated blood glucose and development of severe hyperphagic obesity, whereas either adipose- or liver-specific ASRA knockout mice display increased leptin sensitivity, improved glucose homeostasis, reduced food intake, and resistance to high fat diet-induced obesity. Furthermore, ASRA is indispensable for cold-evoked feeding response. Recombinant ASRA (rASRA) protein binds to leptin receptor and suppresses leptin receptor signaling in cultured cells. In vivo, rASRA promotes food intake and increases blood glucose in a leptin receptor signaling-dependent manner. Our studies collectively show that ASRA, acting as a peripheral signal of energy deficit, stimulates appetite and regulates glucose metabolism by antagonizing leptin receptor signaling, thus revealing a previously unknown endocrine mechanism that has important implications for our understanding of leptin resistance.

12.
Adv Sci (Weinh) ; 10(28): e2301855, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37544897

RESUMO

Mitochondria are the pivot organelles to control metabolism and energy homeostasis. The capacity of mitochondrial metabolic adaptions to cold stress is essential for adipocyte thermogenesis. How brown adipocytes keep mitochondrial fitness upon a challenge of cold-induced oxidative stress has not been well characterized. This manuscript shows that IFI27 plays an important role in cristae morphogenesis, keeping intact succinate dehydrogenase (SDH) function and active fatty acid oxidation to sustain thermogenesis in brown adipocytes. IFI27 protein interaction map identifies SDHB and HADHA as its binding partners. IFI27 physically links SDHB to chaperone TNF receptor associated protein 1 (TRAP1), which shields SDHB from oxidative damage-triggered degradation. Moreover, IFI27 increases hydroxyacyl-CoA dehydrogenase trifunctional multienzyme complex subunit alpha (HADHA) catalytic activity in ß-oxidation pathway. The reduced SDH level and fatty acid oxidation in Ifi27-knockout brown fat results in impaired oxygen consumption and defective thermogenesis. Thus, IFI27 is a novel regulator of mitochondrial metabolism and thermogenesis.


Assuntos
Adipócitos Marrons , Ácido Succínico , Ácido Succínico/metabolismo , Adipócitos Marrons/metabolismo , Tecido Adiposo Marrom/metabolismo , Ácidos Graxos/metabolismo , Termogênese/fisiologia
13.
Graefes Arch Clin Exp Ophthalmol ; 250(8): 1213-20, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22215258

RESUMO

PURPOSE: To investigate the influence of rosiglitazone on activation of human Tenon's fibroblasts (HTFs) and to access the possible mechanism. METHODS: Cultured human Tenon's fibroblasts were pretreated in two different concentrations of rosiglitazone (5 µmol/l and 10 µmol/l) before being stimulated with 5 ng/ml transforming growth factor ß1 (TGF-ß1). The viability and proliferation of cells were accessed by cell count kit-8 assay; Cell migration was examined by the wound closure assay; Alpha smooth muscle actin (α-SMA), connective tissue growth factor (CTGF) and type I collagen (COL I) transcription were detected by RT-qPCR; The expression and localization of α-SMA protein were examined by Western-blot analysis and Immunofluorescence staining; Western-blot analysis was also used to check the expression of CTGF, COL I peroxisome proliferator-activated receptor gamma (PPAR-γ), and phosphorylation of the signaling protein Smad2/3 RESULTS: Rosiglitazone is able to attenuate the up-regulation of α-SMA, CTGF, and COL I transcription, as well as affect protein expression, proliferation, and migration of cells; rosiglitazone also can increase PPAR-γ expression and attenuate Smad2/3 phosphorylation. CONCLUSIONS: Rosiglitazone can effectively attenuate activation of HTFs induced by TGF-ß1 without obvious toxicity. The possible mechanism might be that rosiglitazone interferes with TGF-ß/Smad signaling pathway.


Assuntos
Fibroblastos/efeitos dos fármacos , Hipoglicemiantes/toxicidade , Cápsula de Tenon/citologia , Tiazolidinedionas/toxicidade , Fator de Crescimento Transformador beta1/farmacologia , Actinas/genética , Actinas/metabolismo , Western Blotting , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular , Células Cultivadas , Colágeno Tipo I/genética , Colágeno Tipo I/metabolismo , Fator de Crescimento do Tecido Conjuntivo/genética , Fator de Crescimento do Tecido Conjuntivo/metabolismo , Fibroblastos/metabolismo , Técnica Indireta de Fluorescência para Anticorpo , Humanos , PPAR gama/metabolismo , Fosforilação , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Rosiglitazona , Proteína Smad2/metabolismo , Proteína Smad3/metabolismo , Regulação para Cima
14.
Nat Commun ; 13(1): 7633, 2022 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-36496438

RESUMO

The signaling mechanisms underlying adipose thermogenesis have not been fully elucidated. Particularly, the involvement of adipokines that are selectively expressed in brown adipose tissue (BAT) and beige adipocytes remains to be investigated. Here we show that a previously uncharacterized adipokine (UPF0687 protein / human C20orf27 homolog) we named as Adissp (Adipose-secreted signaling protein) is a key regulator for white adipose tissue (WAT) thermogenesis and glucose homeostasis. Adissp expression is adipose-specific and highly BAT-enriched, and its secretion is stimulated by ß3-adrenergic activation. Gain-of-functional studies collectively showed that secreted Adissp promotes WAT thermogenesis, improves glucose homeostasis, and protects against obesity. Adipose-specific Adissp knockout mice are defective in WAT browning, and are susceptible to high fat diet-induced obesity and hyperglycemia. Mechanistically, Adissp binds to a putative receptor on adipocyte surface and activates protein kinase A independently of ß-adrenergic signaling. These results establish BAT-enriched Adissp as a major upstream signaling component in thermogenesis and offer a potential avenue for the treatment of obesity and diabetes.


Assuntos
Adipocinas , Tecido Adiposo Marrom , Camundongos , Animais , Humanos , Tecido Adiposo Marrom/metabolismo , Termogênese , Tecido Adiposo Branco/metabolismo , Obesidade/metabolismo , Glucose/metabolismo , Adrenérgicos/metabolismo , Adipócitos Marrons/metabolismo , Metabolismo Energético
15.
Diabetes ; 71(9): 1862-1879, 2022 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-35709007

RESUMO

Brown and beige adipocytes dissipate energy in a nonshivering thermogenesis manner, exerting beneficial effects on metabolic homeostasis. CHCHD10 is a nuclear-encoded mitochondrial protein involved in cristae organization; however, its role in thermogenic adipocytes remains unknown. We identify CHCHD10 as a novel regulator for adipocyte thermogenesis. CHCHD10 is dramatically upregulated during thermogenic adipocyte activation by PPARγ-PGC1α and positively correlated with UCP1 expression in adipose tissues from humans and mice. We generated adipocyte-specific Chchd10 knockout mice (Chchd10-AKO) and found that depleting CHCHD10 leads to impaired UCP1-dependent thermogenesis and energy expenditure in the fasting state, with no effect in the fed state. Lipolysis in adipocytes is disrupted by CHCHD10 deficiency, while augmented lipolysis through ATGL overexpression recovers adipocyte thermogenesis in Chchd10-AKO mice. Consistently, overexpression of Chchd10 activates thermogenic adipocytes. Mechanistically, CHCHD10 deficiency results in the disorganization of mitochondrial cristae, leading to impairment of oxidative phosphorylation complex assembly in mitochondria, which in turn inhibits ATP generation. Decreased ATP results in downregulation of lipolysis by reducing nascent protein synthesis of ATGL, thereby suppressing adipocyte thermogenesis. As a result, Chchd10-AKO mice are prone to develop high-fat diet-induced metabolic disorders. Together, our findings reveal an essential role of CHCHD10 in regulating lipolysis and the thermogenic program in adipocytes.


Assuntos
Adipócitos Bege , Adipócitos Marrons , Lipólise , Proteínas Mitocondriais , Termogênese , Trifosfato de Adenosina/metabolismo , Adipócitos Bege/metabolismo , Adipócitos Marrons/metabolismo , Animais , Humanos , Lipólise/genética , Camundongos , Camundongos Knockout , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Proteína Desacopladora 1/genética , Proteína Desacopladora 1/metabolismo
16.
Optom Vis Sci ; 88(7): 850-4, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21499165

RESUMO

PURPOSE: To evaluate the agreement between intraocular pressure (IOP) readings measured by the Ocular Response Analyzer (ORA) and corrected Goldmann applanation tonometry (cGAT), derived from the "gold standard" for the clinical measurement of IOP, in eyes of subjects who have undergone laser in situ keratomileusis (LASIK). The effects of corneal biomechanical properties on IOP were also evaluated. METHODS: This was a retrospective cross-sectional study. The IOP of 148 eyes of 148 patients who have undergone LASIK was measured by the ORA and GAT one after another. cGAT was calculated according to a correction formula for IOP after LASIK. Central corneal thicknesses and corneal curvature (K value) were also measured. Corneal hysteresis and corneal resistance factor (CRF) were measured by the ORA. RESULTS: For the postoperative subjects, whose ages ranged from 18 to 37 years, the average IOP readings for GAT, cGAT, IOPg, IOPcc were 10.09 ± 2.43, 13.34 ± 2.52, 9.79 ± 2.52, 13.91 ± 2.26 mm Hg, respectively. The mean difference between IOPcc and cGAT was 0.63 ± 1.31 mm Hg (p<0.05). The upper and lower limits of agreement between the IOPcc and cGAT were +3.2 and -1.9 mm Hg. There was a significant correlation between cGAT and CRF; however, no significant correlation could be found between cGAT and corneal hysteresis. CONCLUSIONS: After being corrected for central corneal thinkness, curvature of the corneal anterior surface and reduced biomechanical bending strength of the cornea, the IOP reading obtained by GAT is in fair agreement with that obtained by IOPcc, which may be helpful for IOP readings in subjects after LASIK. CRF might be a factor that affects accurate IOP readings.


Assuntos
Pressão Intraocular , Ceratomileuse Assistida por Excimer Laser In Situ , Adolescente , Adulto , Fenômenos Biomecânicos , Córnea/fisiopatologia , Estudos Transversais , Elasticidade , Feminino , Humanos , Masculino , Período Pós-Operatório , Estudos Retrospectivos , Tonometria Ocular , Adulto Jovem
17.
Adv Sci (Weinh) ; 8(16): e2102060, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34180153

RESUMO

Histone deacetylases (HDACs) are widely involved in many biological processes, as well as in control of brown and beige adipose physiology, but the precise molecular mechanisms by which HDACs are assembled into transcriptional machinery to fine-tune thermogenic program remain ill-defined. PWWP domain containing 2b (PWWP2B), which is identified as a component of the nucleosome remodeling and deacetylation complex (NuRD), interacts and stabilizes HDAC1/2 at the thermogenic gene promoters to suppress their expression. Ablation of Pwwp2b promotes adipocyte thermogenesis and ameliorates diet-induced obesity in vivo. Intriguingly, Pwwp2b is not only a brown fat-enriched gene but also dramatically induced by cold and sympathetic stimulation, which may serve as a physiological brake to avoid over-activation of thermogenesis in brown and beige fat cells.

18.
Redox Biol ; 43: 101979, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33895484

RESUMO

Loss of perivascular adipose tissue (PVAT) impairs endothelial function and enhances atherosclerosis. However, the roles of PVAT thermoregulation in vascular inflammation and the development of atherosclerosis remains unclear. Bone morphogenetic protein 4 (BMP4) transforms white adipocyte to beige adipocyte, while promotes a brown-to-white shift in inter-scapular brown adipose tissue (BAT). Here, we found that knockdown of BMP4 in PVAT reduced expression of brown adipocyte-characteristic genes and increased endothelial inflammation in vitro co-culture system. Ablating BMP4 expression either in adipose tissues or specifically in BAT in ApoE-/- mice demonstrated a marked exacerbation of atherosclerotic plaque formation in vivo. We further demonstrated that proinflammatory factors (especially IL-1ß) increased in the supernatant of BMP4 knockdown adipocytes. Overexpression of BMP4 in adipose tissues promotes browning of PVAT and protects against atherosclerosis in ApoE-/- mice. These findings uncover an organ crosstalk between PVAT and blood endothelial cells that is engaged in atherosclerosis.


Assuntos
Aterosclerose , Células Endoteliais , Tecido Adiposo , Tecido Adiposo Marrom , Tecido Adiposo Branco , Animais , Anti-Inflamatórios , Proteína Morfogenética Óssea 4 , Camundongos
19.
Nat Metab ; 3(11): 1536-1551, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34782792

RESUMO

Beiging of white adipose tissue (WAT) is associated with an increase of anti-inflammatory M2-like macrophages in WAT. However, mechanisms through which M2-like macrophages affect beiging are incompletely understood. Here, we show that the macrophage cytokine Slit3 is secreted by adipose tissue macrophages and promotes cold adaptation by stimulating sympathetic innervation and thermogenesis in mice. Analysing the transcriptome of M2-like macrophages in murine inguinal WAT (iWAT) after cold exposure, we identify Slit3 as a secreted cytokine. Slit3 binds to the ROBO1 receptor on sympathetic neurons to stimulate Ca2+/calmodulin-dependent protein kinase II signalling and norepinephrine release, which enhances adipocyte thermogenesis. Adoptive transfer of Slit3-overexpressing M2 macrophages to iWAT promotes beiging and thermogenesis, whereas mice that lack Slit3 in myeloid cells are cold-intolerant and gain more weight. Our findings shed new light on the integral role of M2-like macrophages for adipose tissue homeostasis and uncover the macrophage-Slit3-sympathetic neuron-adipocyte signalling axis as a regulator of long-term cold adaptation.


Assuntos
Tecido Adiposo/inervação , Tecido Adiposo/fisiologia , Fibras Adrenérgicas/fisiologia , Macrófagos/metabolismo , Proteínas de Membrana/biossíntese , Termogênese , Tecido Adiposo Branco/inervação , Tecido Adiposo Branco/metabolismo , Animais , Plasticidade Celular , Metabolismo Energético , Regulação da Expressão Gênica , Proteínas de Membrana/genética , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Células Mieloides/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Especificidade de Órgãos/genética , Fosforilação , Ligação Proteica , Receptores Imunológicos/metabolismo , Temperatura , Termogênese/genética , Proteínas Roundabout
20.
Sci Immunol ; 6(61)2021 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-34330814

RESUMO

IL-33-associated type 2 innate immunity has been shown to support beige fat formation and thermogenesis in subcutaneous inguinal white adipose tissue (iWAT), but little is known about how it is regulated in iWAT. Chemerin, as a newly identified adipokine, is clinically associated with obesity and metabolic disorders. We here show that cold exposure specifically reduces chemerin and its receptor chemerin chemokine-like receptor 1 (CMKLR1) expression in iWAT. Lack of chemerin or adipocytic CMKLR1 enhances cold-induced thermogenic beige fat via potentiating type 2 innate immune responses. Mechanistically, we identify adipocytes, particularly beige adipocytes, as the main source for cold-induced IL-33, which is restricted by the chemerin-CMKLR1 axis via dampening cAMP-PKA signaling, thereby interrupting a feed-forward circuit between beige adipocytes and type 2 innate immunity that is required for cold-induced beige fat and thermogenesis. Moreover, specific deletion of adipocytic IL-33 inhibits cold-induced beige fat and type 2 innate immune responses. Last, genetic blockade of adipocytic CMKLR1 protects against diet-induced obesity and enhances the metabolic benefits of cold stimulation in preestablished obese mice. Thus, our study identifies the chemerin-CMKLR1 axis as a physiological negative regulator of thermogenic beige fat via interrupting adipose-immune communication and suggests targeting adipose CMKLR1 as a potential therapeutic strategy for obesity-related metabolic disorders.


Assuntos
Adipócitos Bege/fisiologia , Quimiocinas/fisiologia , Peptídeos e Proteínas de Sinalização Intercelular/fisiologia , Interleucina-33/fisiologia , Receptores de Quimiocinas/fisiologia , Termogênese , Adipócitos/fisiologia , Adipócitos Bege/imunologia , Animais , Quimiocinas/genética , Quimiocinas/imunologia , Temperatura Baixa , Dieta Hiperlipídica , Humanos , Imunidade Inata , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/imunologia , Interleucina-33/imunologia , Masculino , Camundongos Transgênicos , Obesidade/imunologia , Obesidade/fisiopatologia , Receptores de Quimiocinas/genética , Receptores de Quimiocinas/imunologia
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