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1.
Clin Exp Immunol ; 212(3): 239-248, 2023 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-36966354

RESUMO

Immune-related adverse events (irAEs) clinically resemble autoimmune diseases, indicating autoantibodies could be potential biomarkers for the prediction of irAEs. This study aimed to assess the predictive value of peripheral blood antinuclear antibody (ANA) status for irAEs, considering the time and severity of irAEs, as well as treatment outcome in liver cancer patients administered anti-PD-1 therapy. Ninety-three patients with advanced primary liver cancer administered anti-PD-1 treatment were analyzed retrospectively. They were divided into the ANA positive (ANA+, titer ≥ 1:100) and negative (ANA-, titer < 1:100) groups. Development of irAEs, progression-free survival (PFS), and overall survival (OS) were assessed. Compared with ANA- patients, ANA+ cases were more prone to develop irAEs (43.3% vs. 19.2%, P = 0.031). With the increase of ANA titers, the frequency of irAEs increased. The time interval between anti-PD-1 therapy and the onset of irAEs was significantly shorter in ANA+ patients compared with the ANA- group (median, 1.7 months vs. 5.0 months, P = 0.022). Moreover, the time between anti-PD-1 therapy and irAE occurrence decreased with increasing ANA titer. In addition, PFS and OS were decreased in ANA+ patients compared with the ANA- group (median PFS, 2.8 months vs. 4.2 months, P = 0.043; median OS, 21.1 months vs. not reached, P = 0.041). IrAEs occur at higher frequency in ANA+ liver cancer patients undergoing anti-PD-1 therapy. ANA titer could help predict irAE development and treatment outcome in these patients.


Assuntos
Antineoplásicos Imunológicos , Doenças do Sistema Imunitário , Neoplasias Hepáticas , Humanos , Nivolumabe/efeitos adversos , Anticorpos Antinucleares , Estudos Retrospectivos , Doenças do Sistema Imunitário/induzido quimicamente , Neoplasias Hepáticas/tratamento farmacológico
2.
Biochem Biophys Res Commun ; 464(2): 396-400, 2015 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-26102032

RESUMO

Leucine-rich repeat-containing G protein-coupled receptor 4 (Lgr4) is a newfound obese-associated gene. Previous study reveals that heterozygous mutation of Lgr4 correlates with decreased body weight in human. In our recent study, we demonstrate that Lgr4 ablation promotes browning of white adipose tissue and improves whole-body metabolic status. However little is known about its role in other metabolic tissues. Herein, we show that Lgr4 homozygous mutant (Lgr4(m/m)) mice show increased respiratory exchange ratio (RER, closer to 1.0) than wild-type mice at 12:00 AM (food-intake time for mice) while decreased RER (closer to 0.75) at 12:00 PM (fasting for mice), indicating a glucose-prone versus fatty acid-prone metabolic pattern, respectively. Furthermore, Lgr4 ablation increases lipid oxidation-related gene expression while suppresses glucose transporter type 4 (Glut4) levels in skeletal muscle under fasting condition. These data suggest that Lgr4 ablation enhances the flexibility of skeletal muscle to switch energy provider from glucose to fatty acid in response to glucose depletion. We further reveal the activation of Ampk/Sirt1/Pgc1α pathway during this adaptive fuel shift due to Lgr4 ablation. This study suggests that Lgr4 might serve as an adaptive regulator between glucose and lipid metabolism in skeletal muscle and reveals a potentially new regulator for a well-established adaptive network.


Assuntos
Adenilato Quinase/metabolismo , Metabolismo Energético , Músculo Esquelético/metabolismo , Receptores Acoplados a Proteínas G/fisiologia , Sirtuína 1/metabolismo , Fatores de Transcrição/metabolismo , Animais , Jejum , Insulina/metabolismo , Camundongos , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Receptores Acoplados a Proteínas G/genética
3.
iScience ; 26(5): 106552, 2023 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-37128605

RESUMO

Canonical WNT pathway in mature adipocytes exacerbates obesity. In this study, we constructed UCP1-positive adipocytes-specific Ctnnb1 knockout mice (UBKO) and observed increased "browning" of white adipose tissue (WAT) following cold exposure or CL-316,243 administration compared to controls. UBKO mice also displayed increased energy expenditure. Furthermore, ß-catenin (encoded by Ctnnb1) inhibited thermogenic genes expression in differentiated beige adipocytes and repressed Ucp1 expression at transcription level. Transcriptome analysis revealed UBKO mice treated with CL-316,243 had enhanced mitochondrial function and downregulated immune-related genes in epididymal WAT. Improved glucose tolerance and insulin sensitivity were observed in 50-week-old UBKO mice. Public datasets indicated that CTNNB1 expression was inversely correlated with several thermogenic genes expression in human adipose tissue/adipocytes and positively correlated with BMI or waist-hip ratio (WHR). We proposed that intervention of ß-catenin in adipocytes could be an effective strategy to enhance energy expenditure and improve age-related metabolic performance.

4.
Heliyon ; 9(3): e13269, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36950598

RESUMO

Cancer/testis antigens (CTAs) are reproductive tissue-restricted genes, frequently ectopic expressed in tumors. CTA genes associate with a poor prognosis in some solid tumors, due to their potential roles in the tumorigenesis and progression. However, whether CTAs relate with hepatocellular carcinoma (HCC) remains unclear. In this study, the prognostic signatures based on CTA genes were investigated and validated in three cohorts including Chinese HCC patients with hepatitis B virus infection (CHCC-HBV), International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA) cohorts. Univariate, LASSO, and multivariate Cox regression analyses were used to screen prognostic genes and develop the prognostic gene signature. A prognosis model was established with six CTA genes (SSX1, CTCFL, OIP5, CEP55, NOL4, and TPPP2) in CHCC-HBV cohort, and further validated in the ICGC and TCGA cohorts. The CTA signature was an essential prognostic predictor independent of other clinical pathological factors. High-risk group exhibited up-regulated cell cycle-related and tumor-related pathways and more M0 macrophage, activated mast cell, activated memory CD4+ T cell, and memory B cell infiltration. Furthermore, CTA signature correlated with the sensitivity to multiple chemotherapy drugs. Our results highlighted that the CTA gene profiling was a prognostic assessment tool for HCC patients.

5.
Acad Radiol ; 28 Suppl 1: S157-S166, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-33653656

RESUMO

OBJECTIVE: This study aimed to assess the efficacy and safety of hepatic arterial infusion chemotherapy (HAIC) with modified FOLFOX (5-fluorouracil, leucovorin, and oxaliplatin) as an alternative treatment option in advanced hepatocellular carcinoma (HCC) patients with failed or unsuitability for transarterial chemoembolization (TACE). MATERIALS AND METHODS: From September 2018 to January 2020, 87 advanced HCC patients who progressed on TACE or were not eligible for TACE received HAIC treatment with modified FOLFOX. The primary endpoint was overall survival (OS) and secondary endpoints included progression-free survival (PFS), tumor response assessed by Response Evaluation Criteria in Solid Tumors 1.1, and adverse events graded according to CTCAE 5.0. Based on prognostic factors determined by multivariate analysis, a nomogram was developed to predict patient survival. RESULTS: The median OS and PFS were 9.0 months (95%CI 7.6-10.4) and 3.7 months (95%CI 3.1-4.3), respectively. The objective response rate was 13.8%, with a disease control rate of 48.3%. Grade 3 adverse events were observed, such as infection (9.2%), thrombocytopenia (5.7%), hyperbilirubinemia (3.4%), abdominal pain (2.3%) and alanine aminotransferase increase (2.3%). Albumin, AST, and extrahepatic metastasis were incorporated to construct a new nomogram that could stratify patients into three prognostic subgroups, including low-, intermediate-, and high-risk groups, with significant differences in 9-month OS rates (71%, 42% and 6%, respectively; p< 0.001). The nomogram was better than the Okuda, AJCC, and CLIP staging systems for OS prediction. CONCLUSION: These findings support the feasibility of HAIC with modified FOLFOX as an alternative treatment strategy for advanced HCC when TACE is ineffective or unsuitable.


Assuntos
Carcinoma Hepatocelular , Quimioembolização Terapêutica , Neoplasias Hepáticas , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/terapia , Fluoruracila/uso terapêutico , Humanos , Infusões Intra-Arteriais , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/terapia , Resultado do Tratamento
6.
Sci Adv ; 6(2): eaax9605, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31934629

RESUMO

Overnutrition results in adiposity and chronic inflammation with expansion of white adipose tissue (WAT). However, genetic factors controlling fat mass and adiposity remain largely undetermined. We applied whole-exome sequencing in young obese subjects and identified rare gain-of-function mutations in CTNNB1/ß-catenin associated with increased obesity risk. Specific ablation of ß-catenin in mature adipocytes attenuated high-fat diet-induced obesity and reduced sWAT mass expansion with less proliferated Pdgfrα+ preadipocytes and less mature adipocytes. Mechanistically, ß-catenin regulated the transcription of serum amyloid A3 (Saa3), an adipocyte-derived chemokine, through ß-catenin-TCF (T-Cell-Specific Transcription Factor) complex in mature adipocytes, and Saa3 activated macrophages to secrete several factors, including Pdgf-aa, which further promoted the proliferation of preadipocytes, suggesting that ß-catenin/Saa3/macrophages may mediate mature adipocyte-preadipocyte cross-talk and fat expansion in sWAT. The identification of ß-catenin as a key regulator in fat expansion and human adiposity provides the basis for developing drugs targeting Wnt/ß-catenin pathway to combat obesity.


Assuntos
Adipócitos/citologia , Adipócitos/metabolismo , Adiposidade , Diferenciação Celular , beta Catenina/genética , Células 3T3-L1 , Tecido Adiposo Branco/metabolismo , Animais , Sítios de Ligação , Proliferação de Células , Dieta Hiperlipídica , Mutação com Ganho de Função/genética , Homeostase , Humanos , Ativação de Macrófagos , Camundongos , Camundongos Knockout , Obesidade/genética , Obesidade/patologia , Tamanho do Órgão , Células RAW 264.7 , Proteína Amiloide A Sérica/metabolismo , Fatores de Transcrição TCF/metabolismo , Transcrição Gênica , Via de Sinalização Wnt
7.
Endocrine ; 56(2): 366-378, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28243972

RESUMO

PURPOSE: DGAT2 is the critical catalyzing enzyme for triglyceride biosynthesis, and excess triglyceride accumulation in fat tissues is a fundamental process for obesity. Mutations in DGAT2 or other genes interacting with DGAT2 associated with adiposity have not been reported in human to date. METHODS: DGAT2 mutation was identified based on our in-home database-exome sequencing 227 young obese subjects (body-mass index (BMI), 35.1-61.7 kg/m2) and 219 lean controls (BMI, 17.5-23.0 kg/m2), further validated in 1190 lean subjects and the pedigree of the proband. The trios of the proband were further subjected to whole-exome sequencing to explore the candidate genes for obesity. The mutations in DGAT2 and FAAH were functionally evaluated in vitro. RESULTS: We detected two rare variants in DGAT2 with no significant difference between obese and lean individuals. One novel heterozygous nonsense variant c.382C > T (p.R128*) was identified in one obese subject but not in 219 lean subjects and another 1190 lean subjects. Notably, in vitro study showed that R128* mutation severely damaged the TG-biosynthesis ability of DGAT2, and all other R128* carriers in the pedigree were lean. Thus, we further identified a loss-of-function variant c. 944G > T (p.R315I) in FAAH in the proband inheriting from his obese father. Importantly, FAAH overexpression inhibited DGAT2 expression and TG synthesis, while R315I mutant largely eliminated this inhibitory effect. We first report loss-of-function mutations in DGAT2 and FAAH in one obese subject, which may interact with each other to affect the adiposity penetrance, providing a model of genetic interaction associated with human obesity.


Assuntos
Amidoidrolases/genética , Diacilglicerol O-Aciltransferase/genética , Epistasia Genética , Mutação , Obesidade/genética , Adiposidade , Alelos , Animais , Linhagem Celular , Feminino , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Camundongos , Linhagem
8.
Obesity (Silver Spring) ; 25(1): 252-260, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27925416

RESUMO

OBJECTIVE: To determine the relationship of the gain-of-function variant A750T in leucine-rich repeat containing G protein-coupled receptor 4 (LGR4) with central obesity and related metabolic phenotypes. METHODS: The LGR4 A750T (c.2248 G > A) variant was detected by Sanger sequencing in a discovery young population and a validation community-based population with obesity from eastern China. Fat indices determined by anthropometry and computed tomography scans and clinical biochemical measurements were collected for association analysis. RESULTS: LGR4 A750T was significantly correlated with waist circumference (P = 0.030) and waist-to-height ratio (P < 0.001) in the young cohort (N = 594) and with waist-to-hip ratio (P = 0.013) in the community population (N = 1067). Combined analysis showed a significant correlation of the variant with waist circumference (P < 0.001) and waist-to-hip ratio (P = 0.021). Moreover, the variant had a remarkable correlation with abdominal visceral fat area (P = 0.004) and was associated with 2-h plasma insulin (P = 0.009) and the Matsuda index (P = 0.027) after an oral glucose tolerance test in young subjects with obesity. CONCLUSIONS: The LGR4 A750T variant may contribute to central obesity characterized by abdominal visceral fat accumulation.


Assuntos
Variação Genética , Obesidade Abdominal/epidemiologia , Obesidade Abdominal/genética , Receptores Acoplados a Proteínas G/genética , Adolescente , Adulto , Glicemia/metabolismo , Pressão Sanguínea , Índice de Massa Corporal , China , Colesterol/sangue , Técnicas de Genotipagem , Humanos , Insulina/sangue , Resistência à Insulina/genética , Gordura Intra-Abdominal , Modelos Lineares , Reprodutibilidade dos Testes , Tomografia Computadorizada por Raios X , Circunferência da Cintura , Relação Cintura-Quadril , Adulto Jovem
9.
EBioMedicine ; 24: 64-75, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28988979

RESUMO

BACKGROUND: IRX3 was recently reported as the effector of the FTO variants. We aimed to test IRX3's roles in the browning program and to evaluate the association between the genetic variants in IRX3 and human obesity. METHODS: IRX3 expression was examined in beige adipocytes in human and mouse models, and further validated in induced beige adipocytes. The browning capacity of primary preadipocytes was assessed with IRX3 knockdown. Luciferase reporter analysis and ChIP assay were applied to investigate IRX3's effects on UCP1 transcriptional activity. Moreover, genetic analysis of IRX3 was performed in 861 young obese subjects and 916 controls. RESULTS: IRX3 expression was induced in the browning process and was positively correlated with the browning markers. IRX3 knockdown remarkably inhibited UCP1 expression in induced mouse and human beige adipocytes, and also repressed the uncoupled oxygen consumption rate. Further, IRX3 directly bound to UCP1 promoter and increased its transcriptional activity. Moreover, 17 rare heterozygous missense/frameshift IRX3 variants were identified, with a significant enrichment in obese subjects (P=0.038, OR=2.27; 95% CI, 1.02-5.05). CONCLUSIONS: IRX3 deficiency repressed the browning program of white adipocytes partially by regulating UCP1 transcriptional activity. Rare variants of IRX3 were associated with human obesity.


Assuntos
Adipócitos Marrons/metabolismo , Adipócitos Brancos/metabolismo , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Obesidade/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteína Desacopladora 1/genética , Adulto , Animais , Estudos de Casos e Controles , Linhagem Celular , Modelos Animais de Doenças , Feminino , Mutação da Fase de Leitura , Técnicas de Silenciamento de Genes , Predisposição Genética para Doença , Humanos , Masculino , Camundongos , Mutação , Mutação de Sentido Incorreto , Obesidade/genética , Regiões Promotoras Genéticas , Termogênese , Proteína Desacopladora 1/metabolismo , Adulto Jovem
10.
Diabetes ; 66(4): 935-947, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28130309

RESUMO

Some Shanghai Clinical Center f a role of Niemann-Pick type C1 (NPC1) for obesity traits. However, whether the loss-of-function mutations in NPC1 cause adiposity in humans remains unknown. We recruited 25 probands with rare autosomal-recessive Niemann-Pick type C (NP-C) disease and their parents in assessment of the effect of heterozygous NPC1 mutations on adiposity. We found that male NPC1+/- carriers had a significantly higher BMI than matched control subjects or the whole population-based control subjects. Consistently, male NPC1+/- mice had increased fat storage while eating a high-fat diet. We further conducted an in-depth assessment of rare variants in the NPC1 gene in young, severely obese subjects and lean control subjects and identified 17 rare nonsynonymous/frameshift variants in NPC1 (minor allele frequency <1%) that were significantly associated with an increased risk of obesity (3.40% vs. 0.73%, respectively, in obese patients and control subjects, P = 0.0008, odds ratio = 4.8, 95% CI 1.7-13.2), indicating that rare NPC1 variants were enriched in young, morbidly obese Chinese subjects. Importantly, participants carrying rare variants with severely damaged cholesterol-transporting ability had more fat accumulation than those with mild/no damage rare variants. In summary, rare loss-of-function NPC1 mutations were identified as being associated with human adiposity with a high penetrance, providing potential therapeutic interventions for obesity in addition to the role of NPC1 in the familial NP-C disease.


Assuntos
Povo Asiático/genética , Proteínas de Transporte/genética , Dieta Hiperlipídica , Glicoproteínas de Membrana/genética , Obesidade Mórbida/genética , Proteínas/genética , Adulto , Animais , Estudos de Casos e Controles , China , Feminino , Mutação da Fase de Leitura , Frequência do Gene , Predisposição Genética para Doença , Variação Genética , Heterozigoto , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Masculino , Camundongos , Pessoa de Meia-Idade , Proteína C1 de Niemann-Pick , Obesidade/genética , Fenótipo , Adulto Jovem
11.
Endocrinology ; 157(6): 2333-45, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27145005

RESUMO

A growing body of epidemiological research show that Bisphenol A (BPA) is positively correlated with obesity and metabolic disorders. However, the mechanisms of BPA on adiposity remain largely unknown. In this study, we found that 5-week-old male and female C57BL/6J mice exposed to four dosages of BPA (5, 50, 500, and 5000 µg/kg/d) by oral intake for 30 days showed significantly increased body weight and fat mass in a nonmonotonic dose-dependent manner when fed a chow diet. The effect occurred even at the lowest concentration (5µg/kg/d), lower than the tolerable daily intake of 50 µg/kg/day for BPA. However, no significant difference in body weight and fat mass was observed in either male or female mice fed a high-fat diet, suggesting that BPA may interact with diet in promoting obesity risk. In vitro study showed that BPA treatment drives the differentiation of white adipocyte progenitors from the stromal vascular fraction, partially through glucocorticoid receptor. BPA exposure increased circulating inflammatory factors and the local inflammation in white adipose tissues in both genders fed a chow diet, but not under high-fat diet. We further found that BPA concentration was associated with increased circulating inflammatory factors, including leptin and TNFα, in lean female subjects (body mass index < 23.0 kg/m(2)) but not in lean male subjects or in both sexes of overweight/obese subjects (body mass index > 25.0 kg/m(2)). In conclusion, we demonstrated the nonmonotonic dose effects of BPA on adiposity and chronic inflammation in 5-week-old mice, which is related to caloric uptake.


Assuntos
Compostos Benzidrílicos/toxicidade , Inflamação/induzido quimicamente , Fenóis/toxicidade , Adiposidade/efeitos dos fármacos , Adiposidade/genética , Idoso , Animais , Peso Corporal/efeitos dos fármacos , Peso Corporal/genética , Restrição Calórica , Diferenciação Celular/efeitos dos fármacos , Dieta Hiperlipídica/efeitos adversos , Feminino , Humanos , Inflamação/genética , Inflamação/metabolismo , Leptina/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Obesidade/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Receptores de Glucocorticoides/metabolismo
12.
Mol Cell Endocrinol ; 383(1-2): 118-25, 2014 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-24361598

RESUMO

It is known that adipokines can regulate the hypothalamic-pituitary-adrenal axis (HPAA). In this study, we confirmed that adiponectin regulates the HPAA by affecting pituitary corticotroph cells. Using RT-PCR and immunofluorescence, we determined that adiponectin receptors were expressed in pituitary corticotroph tumour cells (AtT-20 cells and human corticotroph tumours). Adiponectin stimulated calcium influx and increased basal ACTH secretion without affecting corticotrophin-releasing hormone (CRH)-stimulated ACTH secretion, which was most likely due to the expression of adiponectin repressing CRH receptor 1 (CRHR1). Adiponectin also acutely stimulated ACTH release in primary culture pituitary cells. Lastly, adiponectin directly phosphorylated 5' AMP-activated protein kinase (AMPK) in AtT-20 cells. The effects of adiponectin were mimicked by AICAR, which was blocked by compound C. Taken together, our results suggested that adiponectin stimulated ACTH secretion and down-regulated CRHR1, possibly via an AMPK-dependent mechanism in pituitary corticotroph cells.


Assuntos
Adiponectina/metabolismo , Hormônio Adrenocorticotrópico/metabolismo , Corticotrofos/metabolismo , Sistema Hipotálamo-Hipofisário/metabolismo , Sistema Hipófise-Suprarrenal/metabolismo , Proteínas Quinases Ativadas por AMP/antagonistas & inibidores , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Adiponectina/farmacologia , Hormônio Adrenocorticotrópico/genética , Aminoimidazol Carboxamida/análogos & derivados , Aminoimidazol Carboxamida/farmacologia , Animais , Cálcio/metabolismo , Linhagem Celular Tumoral , Corticotrofos/citologia , Hormônio Liberador da Corticotropina/genética , Hormônio Liberador da Corticotropina/metabolismo , Regulação da Expressão Gênica , Humanos , Sistema Hipotálamo-Hipofisário/citologia , Masculino , Camundongos , Fosforilação/efeitos dos fármacos , Sistema Hipófise-Suprarrenal/citologia , Cultura Primária de Células , Pirazóis/farmacologia , Pirimidinas/farmacologia , Ratos , Ratos Sprague-Dawley , Receptores de Adiponectina/genética , Receptores de Adiponectina/metabolismo , Receptores de Hormônio Liberador da Corticotropina , Ribonucleotídeos/farmacologia
13.
J Mol Endocrinol ; 52(2): 133-43, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24353284

RESUMO

The circadian clock plays an important role in the liver by regulating the major aspects of energy metabolism. Currently, it is assumed that the circadian clock regulates metabolism mostly by regulating the expression of liver enzymes at the transcriptional level, but the underlying mechanism is not well understood. In this study, we showed that Lgr4 homozygous mutant (Lgr4(m/m)) mice showed alteration in the rhythms of the respiratory exchange ratio. We further detected impaired plasma triglyceride rhythms in Lgr4(m/m) mice. Although no significant changes in plasma cholesterol rhythms were observed in the Lgr4(m/m) mice, their cholesterol levels were obviously lower. This phenotype was further confirmed in the context of ob/ob mice, in which lack of LGR4 dampened circadian rhythms of triglyceride. We next demonstrated that Lgr4 expression exhibited circadian rhythms in the liver tissue and primary hepatocytes in mice, but we did not detect changes in the expression levels or circadian rhythms of classic clock genes, such as Clock, Bmal1 (Arntl), Pers, Rev-erbs, and Crys, in Lgr4(m/m) mice compared with their littermates. Among the genes related to the lipid metabolism, we found that the diurnal expression pattern of the Mttp gene, which plays an important role in the regulation of plasma lipid levels, was impaired in Lgr4(m/m) mice and primary Lgr4(m/m) hepatocytes. Taken together, our results demonstrate that LGR4 plays an important role in the regulation of plasma lipid rhythms, partially through regulating the expression of microsomal triglyceride transfer protein. These data provide a possible link between the peripheral circadian clock and lipid metabolism.


Assuntos
Relógios Circadianos , Metabolismo dos Lipídeos , Fígado/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Animais , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Células Cultivadas , Relógios Circadianos/genética , Ritmo Circadiano/genética , Feminino , Regulação da Expressão Gênica , Hepatócitos/metabolismo , Leptina/deficiência , Leptina/metabolismo , Metabolismo dos Lipídeos/genética , Lipídeos/sangue , Masculino , Camundongos , Camundongos Knockout , Camundongos Obesos , Receptores Acoplados a Proteínas G/genética , Respiração
14.
J Mol Endocrinol ; 53(3): 405-15, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25324487

RESUMO

WNT/ß-catenin signalling is involved in regulating adipogenesis, and its dysregulation occurs in obesity. Secreted frizzled-related protein 5 (SFRP5) is a WNT protein inhibitor; however, its role in adipogenesis and obesity is controversial. In this study, we observed that SFRP5 mRNA levels were increased in the fat tissues of obese humans and mice. Sfrp5 expression was gradually induced during differentiation of white and brown adipocytes and was highly increased in mature adipocytes rather than preadipocytes. However, the effects of the exogenous overexpression of Sfrp5 indicated that Sfrp5 may not directly regulate adipogenesis in vitro under the conditions studied. Moreover, SFRP5 did not inhibit the canonical WNT/ß-catenin signalling pathway in preadipocytes. Subsequently, we measured the levels of circulating SFRP5 in obese patients and non-obese subjects using ELISA and did not find any significant difference. Collectively, these findings indicate that Sfrp5 represents a candidate for a mature adipocyte marker gene. Our data provide new evidence concerning the role of SFRP5 in adipogenesis of white and brown adipocytes and obesity.


Assuntos
Adipócitos/metabolismo , Biomarcadores , Proteínas do Olho/fisiologia , Proteínas de Membrana/fisiologia , Células 3T3-L1 , Proteínas Adaptadoras de Transdução de Sinal , Adipogenia/genética , Tecido Adiposo/metabolismo , Adolescente , Adulto , Animais , Biomarcadores/metabolismo , Estudos de Casos e Controles , Células Cultivadas , Feminino , Células HEK293 , Humanos , Masculino , Camundongos , Camundongos Obesos , Camundongos Transgênicos , Obesidade/sangue , Adulto Jovem
15.
Nat Cell Biol ; 15(12): 1455-63, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24212090

RESUMO

Obesity occurs when excess energy accumulates in white adipose tissue (WAT), whereas brown adipose tissue (BAT), specialized for energy expenditure through thermogenesis, potently counteracts obesity. Factors that induce brown adipocyte commitment and energy expenditure would be a promising defence against adiposity. Here, we show that Lgr4 homozygous mutant (Lgr4(m/m)) mice show reduced adiposity and resist dietary and leptin mutant-induced obesity with improved glucose metabolism. Lgr4(m/m) mice show a striking increase in energy expenditure, and exhibit brown-like adipocytes in WAT depots with higher expression of BAT and beige cell markers. Furthermore, Lgr4 ablation potentiates brown adipocyte differentiation from the stromal vascular fraction of epididymal WAT, partially through retinoblastoma 1 gene (Rb1) reduction. A functional low-frequency human LGR4 variant (A750T) has been associated with body mass index in a Chinese obese-versus-control study. Our results identify an important role for LGR4 in energy balance and body weight control through regulating the white-to-brown fat transition.


Assuntos
Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Obesidade/metabolismo , Receptores Acoplados a Proteínas G/genética , Adipócitos/fisiologia , Adipogenia , Tecido Adiposo Marrom/patologia , Tecido Adiposo Branco/patologia , Adolescente , Adulto , Sequência de Aminoácidos , Animais , Estudos de Casos e Controles , Metabolismo Energético , Feminino , Estudos de Associação Genética , Células HEK293 , Humanos , Desequilíbrio de Ligação , Masculino , Camundongos , Camundongos Endogâmicos C3H , Camundongos Knockout , Camundongos Obesos , Obesidade/genética , Obesidade/patologia , Polimorfismo de Nucleotídeo Único , Receptores Acoplados a Proteínas G/metabolismo , Adulto Jovem
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