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1.
Mol Metab ; 61: 101512, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35550189

RESUMO

BACKGROUND/PURPOSE: Adipose tissue contains progenitor cells that contribute to beneficial tissue expansion when needed by de novo adipocyte formation (classical white or beige fat cells with thermogenic potential). However, in chronic obesity, they can exhibit an activated pro-fibrotic, extracellular matrix (ECM)-depositing phenotype that highly aggravates obesity-related adipose tissue dysfunction. METHODS: Given that progenitors' fibrotic activation and fat cell browning appear to be antagonistic cell fates, we have examined the anti-fibrotic potential of pro-browning agents in an obesogenic condition. RESULTS: In obese mice fed a high fat diet, thermoneutral housing, which induces brown fat cell dormancy, increases the expression of ECM gene programs compared to conventionally raised animals, indicating aggravation of obesity-related tissue fibrosis at thermoneutrality. In a model of primary cultured murine adipose progenitors, we found that exposure to ß-hydroxybutyrate selectively reduced Tgfß-dependent profibrotic responses of ECM genes like Ctgf, Loxl2 and Fn1. This effect is observed in both subcutaneous and visceral-derived adipose progenitors, as well as in 3T3-L1 fibroblasts. In 30 patients with obesity eligible for bariatric surgery, those with higher circulating ß-hydroxybutyrate levels have lower subcutaneous adipose tissue fibrotic scores. Mechanistically, ß-hydroxybutyrate limits Tgfß-dependent collagen accumulation and reduces Smad2-3 protein expression and phosphorylation in visceral progenitors. Moreover, ß-hydroxybutyrate induces the expression of the ZFP36 gene, encoding a post-transcriptional regulator that promotes the degradation of mRNA by binding to AU-rich sites within 3'UTRs. Importantly, complete ZFP36 deficiency in a mouse embryonic fibroblast line from null mice, or siRNA knock-down in primary progenitors, indicate that ZFP36 is required for ß-hydroxybutyrate anti-fibrotic effects. CONCLUSION: These data unravel the potential of ß-hydroxybutyrate to limit adipose tissue matrix deposition, a finding that might exploited in an obesogenic context.


Assuntos
Tecido Adiposo Marrom , Tecido Adiposo Branco , Ácido 3-Hidroxibutírico/metabolismo , Ácido 3-Hidroxibutírico/farmacologia , Adipócitos Marrons/metabolismo , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Animais , Fibroblastos/metabolismo , Fibrose , Humanos , Camundongos , Obesidade/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Tristetraprolina/metabolismo
2.
Gut Microbes ; 14(1): 2050635, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35435140

RESUMO

Roux-en-Y gastric bypass (RYGB) is efficient at inducing drastic albeit variable weight loss and type-2 diabetes (T2D) improvements in patients with severe obesity and T2D. We hypothesized a causal implication of the gut microbiota (GM) in these metabolic benefits, as RYGB is known to deeply impact its composition. In a cohort of 100 patients with baseline T2D who underwent RYGB and were followed for 5-years, we used a hierarchical clustering approach to stratify subjects based on the severity of their T2D (Severe vs Mild) throughout the follow-up. We identified via nanopore-based GM sequencing that the more severe cases of unresolved T2D were associated with a major increase of the class Bacteroidia, including 12 species comprising Phocaeicola dorei, Bacteroides fragilis, and Bacteroides caecimuris. A key observation is that patients who underwent major metabolic improvements do not harbor this enrichment in Bacteroidia, as those who presented mild cases of T2D at all times. In a separate group of 36 patients with similar baseline clinical characteristics and preoperative GM sequencing, we showed that this increase in Bacteroidia was already present at baseline in the most severe cases of T2D. To explore the causal relationship linking this enrichment in Bacteroidia and metabolic alterations, we selected 13 patients across T2D severity clusters at 5-years and performed fecal matter transplants in mice. Our results show that 14 weeks after the transplantations, mice colonized with the GM of Severe donors have impaired glucose tolerance and insulin sensitivity as compared to Mild-recipients, all in the absence of any difference in body weight and composition. GM sequencing of the recipient animals revealed that the hallmark T2D-severity associated bacterial features were transferred and were associated with the animals' metabolic alterations. Therefore, our results further establish the GM as a key contributor to long-term glucose metabolism improvements (or lack thereof) after RYGB.


Assuntos
Diabetes Mellitus Tipo 2 , Derivação Gástrica , Microbioma Gastrointestinal , Animais , Bacteroidetes , Peso Corporal , Diabetes Mellitus Tipo 2/microbiologia , Derivação Gástrica/métodos , Humanos , Camundongos , Redução de Peso
3.
Nat Med ; 28(2): 303-314, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35177860

RESUMO

Previous microbiome and metabolome analyses exploring non-communicable diseases have paid scant attention to major confounders of study outcomes, such as common, pre-morbid and co-morbid conditions, or polypharmacy. Here, in the context of ischemic heart disease (IHD), we used a study design that recapitulates disease initiation, escalation and response to treatment over time, mirroring a longitudinal study that would otherwise be difficult to perform given the protracted nature of IHD pathogenesis. We recruited 1,241 middle-aged Europeans, including healthy individuals, individuals with dysmetabolic morbidities (obesity and type 2 diabetes) but lacking overt IHD diagnosis and individuals with IHD at three distinct clinical stages-acute coronary syndrome, chronic IHD and IHD with heart failure-and characterized their phenome, gut metagenome and serum and urine metabolome. We found that about 75% of microbiome and metabolome features that distinguish individuals with IHD from healthy individuals after adjustment for effects of medication and lifestyle are present in individuals exhibiting dysmetabolism, suggesting that major alterations of the gut microbiome and metabolome might begin long before clinical onset of IHD. We further categorized microbiome and metabolome signatures related to prodromal dysmetabolism, specific to IHD in general or to each of its three subtypes or related to escalation or de-escalation of IHD. Discriminant analysis based on specific IHD microbiome and metabolome features could better differentiate individuals with IHD from healthy individuals or metabolically matched individuals as compared to the conventional risk markers, pointing to a pathophysiological relevance of these features.


Assuntos
Doenças Cardiovasculares , Diabetes Mellitus Tipo 2 , Microbiota , Humanos , Estudos Longitudinais , Metaboloma , Pessoa de Meia-Idade
4.
Gut ; 71(12): 2463-2480, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35017197

RESUMO

OBJECTIVES: Gut microbiota is a key component in obesity and type 2 diabetes, yet mechanisms and metabolites central to this interaction remain unclear. We examined the human gut microbiome's functional composition in healthy metabolic state and the most severe states of obesity and type 2 diabetes within the MetaCardis cohort. We focused on the role of B vitamins and B7/B8 biotin for regulation of host metabolic state, as these vitamins influence both microbial function and host metabolism and inflammation. DESIGN: We performed metagenomic analyses in 1545 subjects from the MetaCardis cohorts and different murine experiments, including germ-free and antibiotic treated animals, faecal microbiota transfer, bariatric surgery and supplementation with biotin and prebiotics in mice. RESULTS: Severe obesity is associated with an absolute deficiency in bacterial biotin producers and transporters, whose abundances correlate with host metabolic and inflammatory phenotypes. We found suboptimal circulating biotin levels in severe obesity and altered expression of biotin-associated genes in human adipose tissue. In mice, the absence or depletion of gut microbiota by antibiotics confirmed the microbial contribution to host biotin levels. Bariatric surgery, which improves metabolism and inflammation, associates with increased bacterial biotin producers and improved host systemic biotin in humans and mice. Finally, supplementing high-fat diet-fed mice with fructo-oligosaccharides and biotin improves not only the microbiome diversity, but also the potential of bacterial production of biotin and B vitamins, while limiting weight gain and glycaemic deterioration. CONCLUSION: Strategies combining biotin and prebiotic supplementation could help prevent the deterioration of metabolic states in severe obesity. TRIAL REGISTRATION NUMBER: NCT02059538.


Assuntos
Diabetes Mellitus Tipo 2 , Microbioma Gastrointestinal , Obesidade Mórbida , Complexo Vitamínico B , Humanos , Camundongos , Animais , Prebióticos , Obesidade Mórbida/cirurgia , Biotina/farmacologia , Complexo Vitamínico B/farmacologia , Camundongos Endogâmicos C57BL , Obesidade/metabolismo , Inflamação
5.
Int J Obes (Lond) ; 46(1): 68-76, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34493775

RESUMO

BACKGROUND/OBJECTIVES: Platelet-activating factor receptor (PAFR) activation controls adipose tissue (AT) expansion in animal models. Our objective was twofold: (i) to check whether PAFR signaling is involved in human obesity and (ii) investigate the PAF pathway role in hematopoietic or non-hematopoietic cells to control adipocyte size. MATERIALS/SUBJECTS AND METHODS: Clinical parameters and adipose tissue gene expression were evaluated in subjects with obesity. Bone marrow (BM) transplantation from wild-type (WT) or PAFR-/- mice was performed to obtain chimeric PAFR-deficient mice predominantly in hematopoietic or non-hematopoietic-derived cells. A high carbohydrate diet (HC) was used to induce AT remodeling and evaluate in which cell compartment PAFR signaling modulates it. Also, 3T3-L1 cells were treated with PAF to evaluate fat accumulation and the expression of genes related to it. RESULTS: PAFR expression in omental AT from humans with obesity was negatively correlated to different corpulence parameters and more expressed in the stromal vascular fraction than adipocytes. Total PAFR-/- increased adiposity compared with WT independent of diet-induced obesity. Differently, WT mice receiving PAFR-/--BM exhibited similar adiposity gain as WT chimeras. PAFR-/- mice receiving WT-BM showed comparable augmentation in adiposity as total PAFR-/- mice, demonstrating that PAFR signaling modulates adipose tissue expansion through non-hematopoietic cells. Indeed, the PAF treatment in 3T3-L1 adipocytes reduced fat accumulation and expression of adipogenic genes. CONCLUSIONS: Therefore, decreased PAFR signaling may favor an AT accumulation in humans and animal models. Importantly, PAFR signaling, mainly in non-hematopoietic cells, especially in adipocytes, appears to play a significant role in regulating diet-induced AT expansion.


Assuntos
Tecido Adiposo/fisiopatologia , Obesidade/complicações , Glicoproteínas da Membrana de Plaquetas/farmacologia , Tecido Adiposo/metabolismo , Adulto , Animais , Modelos Animais de Doenças , Feminino , Humanos , Masculino , Camundongos , Camundongos Knockout , Pessoa de Meia-Idade , Obesidade/fisiopatologia , Paris , Receptores Acoplados a Proteínas G , Transdução de Sinais/fisiologia
6.
Life (Basel) ; 11(10)2021 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-34685423

RESUMO

Peroxisome proliferator-activated receptor γ (PPARγ) is essential for placental development, whose SNPs have shown increased susceptibility to pregnancy-related diseases, such as preeclampsia. Our aim was to investigate the association between preeclampsia and three PPARγ SNPs (Pro12Ala, C1431T, and C681G), which together with nine clinical factors were used to build a pragmatic model for preeclampsia prediction. Data were collected from 1648 women from the EDEN cohort, of which 35 women had preeclamptic pregnancies, and the remaining 1613 women had normal pregnancies. Univariate analysis comparing preeclamptic patients to the control resulted in the SNP C1431T being the only factor significantly associated with preeclampsia (p < 0.05), with a confidence interval of 95% and odds ratio ranging from 4.90 to 8.75. On the other hand, three methods of multivariate feature selection highlighted seven features that could be potential predictors of preeclampsia: maternal C1431T and C681G variants, obesity, body mass index, number of pregnancies, primiparity, cigarette use, and education. These seven features were further used as input into eight different machine-learning algorithms to create predictive models, whose performances were evaluated based on metrics of accuracy and the area under the receiver operating characteristic curve (AUC). The boost tree-based model performed the best, with respective accuracy and AUC values of 0.971 ± 0.002 and 0.991 ± 0.001 in the training set and 0.951 and 0.701 in the testing set. A flowchart based on the boost tree model was constructed to depict the procedure for preeclampsia prediction. This final decision tree showed that the C1431T variant of PPARγ is significantly associated with susceptibility to preeclampsia. We believe that this final decision tree could be applied in the clinical prediction of preeclampsia in the very early stages of pregnancy.

7.
Am J Physiol Endocrinol Metab ; 321(3): E417-E432, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34338041

RESUMO

Carbohydrates and sweeteners are detected by the sweet taste receptor in enteroendocrine cells (EECs). This receptor is coupled to the gustducin G-protein, which α-subunit is encoded by GNAT3 gene. In intestine, the activation of sweet taste receptor triggers a signaling pathway leading to GLP-1 secretion, an incretin hormone. In metabolic diseases, GLP-1 concentration and incretin effect are reduced while partly restored after Roux-en-Y gastric bypass (RYGB). We wondered if the decreased GLP-1 secretion in metabolic diseases is caused by an intestinal defect in sweet taste transduction pathway. In our RNA-sequencing of EECs, GNAT3 expression is decreased in patients with obesity and type 2 diabetes compared with normoglycemic obese patients. This prompted us to explore sweet taste signaling pathway in mice with metabolic deteriorations. During obesity onset in mice, Gnat3 expression was downregulated in EECs. After metabolic improvement with enterogastro anastomosis surgery in mice (a surrogate of the RYGB in humans), the expression of Gnat3 increased in the new alimentary tract and glucose-induced GLP-1 secretion was improved. To evaluate if high-fat diet-induced dysbiotic intestinal microbiota could explain the changes in the expression of sweet taste α-subunit G-protein, we performed a fecal microbiota transfer in mice. However, we could not conclude if dysbiotic microbiota impacted or not intestinal Gnat3 expression. Our data highlight that metabolic disorders were associated with altered gene expression of sweet taste signaling in intestine. This could contribute to impaired GLP-1 secretion that is partly rescued after metabolic improvement.NEW & NOTEWORTHY Our data highlighted 1) the sweet taste transduction pathway in EECs plays pivotal role for glucose homeostasis at least at gene expression level; 2) metabolic disorders lead to altered gene expression of sweet taste signaling pathway in intestine contributing to impaired GLP-1 secretion; and 3) after surgical intestinal modifications, increased expression of GNAT3, encoding α-gustducin contributed to metabolic improvement.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Obesidade/metabolismo , Transdução de Sinais , Paladar , Transducina/metabolismo , Animais , Disbiose/metabolismo , Células Enteroendócrinas/metabolismo , Microbioma Gastrointestinal , Humanos , Masculino , Camundongos Endogâmicos C57BL
8.
Diabetologia ; 64(1): 240-254, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33125520

RESUMO

AIM/HYPOTHESIS: Altered adipose tissue secretory profile contributes to insulin resistance and type 2 diabetes in obesity. Preclinical studies have identified senescent cells as a cellular source of proinflammatory factors in adipose tissue of obese mice. In humans, potential links with obesity comorbidities are poorly defined. Here, we investigated adipose tissue senescent status and relationships with metabolic complications in human obesity. METHODS: The study includes a prospective cohort of 227 individuals with severe obesity. A photometric method was used to quantify senescence-associated ß-galactosidase (SA-ß-gal) activity in paired subcutaneous and omental adipose tissue biopsies obtained during gastric surgery. Gene and secretory profiling was performed in adipose tissue biopsies and in human primary pre-adipocytes in the presence or absence of senolytic drugs targeting senescent cells. Participants were phenotyped for anthropometric and bioclinical variables, metabolic complications and gastric surgery-induced improvement to address relationships with adipose tissue SA-ß-gal. RESULTS: SA-ß-gal activity was sevenfold higher in subcutaneous than in omental adipose tissue and not associated with BMI or chronological age. Several factors, including insulin-like growth factor binding protein 3 (IGFBP3), plasminogen activator inhibitor 1 (PAI1), C-C motif chemokine ligand 2 (CCL2) and IL-6, were upregulated in subcutaneous adipose tissue in relation with SA-ß-gal (p for linear trend across tertiles <0.05) and in pre-adipocytes cultured with inflammatory macrophage conditioned media. Senolytic treatment reduced SA-ß-gal staining and normalised these alterations. In the whole population, subcutaneous adipose tissue SA-ß-gal activity was positively associated with serum leptin, markers of insulin resistance and increased trunk fat mass. Metabolic complications, including type 2 diabetes and dyslipidaemia, were more prevalent in patients with high levels of SA-ß-gal, but improved with bariatric surgery whatever the initial adipose tissue senescent status. CONCLUSIONS/INTERPRETATION: This study highlights a phenotype of senescence in adipose tissue of severely obese individuals, which characterises prominently subcutaneous fat depots. Subcutaneous adipose tissue senescence is significantly linked to altered glucose metabolism and body fat distribution. Elimination of senescent cells through senolytic treatment could alleviate metabolic complications in severely obese people. Graphical abstract.


Assuntos
Glicemia/análise , Composição Corporal/fisiologia , Senescência Celular/fisiologia , Obesidade Mórbida/fisiopatologia , Gordura Subcutânea/enzimologia , beta-Galactosidase/metabolismo , Adipócitos/fisiologia , Cirurgia Bariátrica , Biópsia , Estudos de Coortes , Feminino , Humanos , Resistência à Insulina , Masculino , Obesidade Mórbida/metabolismo , Obesidade Mórbida/cirurgia , Estudos Prospectivos , Gordura Subcutânea/patologia , Resultado do Tratamento
9.
EBioMedicine ; 58: 102895, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32739864

RESUMO

BACKGROUND: Bariatric surgery is an effective treatment for type 2 diabetes. Early post-surgical enhancement of insulin secretion is key for diabetes remission. The full complement of mechanisms responsible for improved pancreatic beta cell functionality after bariatric surgery is still unclear. Our aim was to identify pathways, evident in the islet transcriptome, that characterize the adaptive response to bariatric surgery independently of body weight changes. METHODS: We performed entero-gastro-anastomosis (EGA) with pyloric ligature in leptin-deficient ob/ob mice as a surrogate of Roux-en-Y gastric bypass (RYGB) in humans. Multiple approaches such as determination of glucose tolerance, GLP-1 and insulin secretion, whole body insulin sensitivity, ex vivo glucose-stimulated insulin secretion (GSIS) and functional multicellular Ca2+-imaging, profiling of mRNA and of miRNA expression were utilized to identify significant biological processes involved in pancreatic islet recovery. FINDINGS: EGA resolved diabetes, increased pancreatic insulin content and GSIS despite a persistent increase in fat mass, systemic and intra-islet inflammation, and lipotoxicity. Surgery differentially regulated 193 genes in the islet, most of which were involved in the regulation of glucose metabolism, insulin secretion, calcium signaling or beta cell viability, and these were normalized alongside changes in glucose metabolism, intracellular Ca2+ dynamics and the threshold for GSIS. Furthermore, 27 islet miRNAs were differentially regulated, four of them hubs in a miRNA-gene interaction network and four others part of a blood signature of diabetes resolution in ob/ob mice and in humans. INTERPRETATION: Taken together, our data highlight novel miRNA-gene interactions in the pancreatic islet during the resolution of diabetes after bariatric surgery that form part of a blood signature of diabetes reversal. FUNDING: European Union's Horizon 2020 research and innovation programme via the Innovative Medicines Initiative 2 Joint Undertaking (RHAPSODY), INSERM, Société Francophone du Diabète, Institut Benjamin Delessert, Wellcome Trust Investigator Award (212625/Z/18/Z), MRC Programme grants (MR/R022259/1, MR/J0003042/1, MR/L020149/1), Diabetes UK (BDA/11/0004210, BDA/15/0005275, BDA 16/0005485) project grants, National Science Foundation (310030-188447), Fondation de l'Avenir.


Assuntos
Diabetes Mellitus Tipo 2/cirurgia , Redes Reguladoras de Genes , Células Secretoras de Insulina/química , MicroRNAs/genética , Obesidade/cirurgia , Animais , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Modelos Animais de Doenças , Derivação Gástrica , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Teste de Tolerância a Glucose , Humanos , Insulina/metabolismo , Masculino , Camundongos , Camundongos Obesos , Obesidade/genética , Obesidade/metabolismo
10.
Ann Rheum Dis ; 76(6): 1142-1148, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28298375

RESUMO

OBJECTIVES: Compared with subcutaneous adipose tissue (SCAT), infrapatellar fat pad (IFP), the main knee intra-articular adipose tissue (IAAT), has an inflammatory phenotype in patients with osteoarthritis (OA). We phenotyped suprapatellar fat pad (SPFP) and hip acetabular fat pad (AFP), two other IAATs, to determinate the unique signature of IAATs compared with SCAT. METHODS: IFP, SPFP, AFP and autologous SCAT were obtained from patients with OA during total knee (n=38) or hip replacement (n=5). Fibrosis and adipocyte area were analysed by histology and vascularisation, leucocyte and mast cell infiltration were analysed by immunohistochemistry for von Willebrand factor, leucocytes and tryptase, respectively. Secretion of interleukin (IL)-6, IL-8 and prostaglandin E2 (PGE2) was assessed by ELISA. The mRNA expression of adipocyte-associated genes (ATGL, LPL, PPAR-γ, FABP4 and CD36) and developmental genes (SFRP2, HoxC9 and EN1) was determined. The inflammatory response of isolated fibroblast-like synoviocytes (FLS) to autologous IFP and SPFP conditioned media was examined. RESULTS: Fibrosis, vascularisation and leucocyte and mast cell infiltration were greater in IAATs than SCAT, and levels of IL-6, IL-8 and PGE2 were greater in all IAATs than SCAT. IFP and SPFP induced a similar inflammatory response to FLS. Adipocyte area was smaller in IAATs than SCAT. Adipocyte-associated and developmental genes showed a similar gene expression pattern in all IAATs, different from SCAT. CONCLUSIONS: IFP but also SPFP and AFP (gathered under the term 'IAAT') may play a deleterious role in OA by affecting joint homeostasis because of their inflammatory phenotype and their close interaction with synovium in the same functional unit.


Assuntos
Tecido Adiposo/metabolismo , Tecido Adiposo/patologia , Articulação do Quadril , Articulação do Joelho , Osteoartrite do Quadril/metabolismo , Osteoartrite do Joelho/metabolismo , RNA Mensageiro/metabolismo , Adipócitos/metabolismo , Adipócitos/patologia , Adolescente , Adulto , Idoso , Antígenos CD36/genética , Meios de Cultivo Condicionados/farmacologia , Dinoprostona/metabolismo , Proteínas de Ligação a Ácido Graxo/genética , Feminino , Expressão Gênica , Proteínas de Homeodomínio/genética , Humanos , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Lipase/genética , Lipase Lipoproteica/genética , Masculino , Proteínas de Membrana/genética , Pessoa de Meia-Idade , Osteoartrite do Quadril/genética , Osteoartrite do Joelho/genética , PPAR gama/genética , Fenótipo , Gordura Subcutânea/metabolismo , Gordura Subcutânea/patologia , Sinoviócitos/efeitos dos fármacos , Adulto Jovem
11.
Cell Metab ; 25(3): 673-685, 2017 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-28215843

RESUMO

Obesity-induced white adipose tissue (WAT) fibrosis is believed to accelerate WAT dysfunction. However, the cellular origin of WAT fibrosis remains unclear. Here, we show that adipocyte platelet-derived growth factor receptor-α-positive (PDGFRα+) progenitors adopt a fibrogenic phenotype in obese mice prone to visceral WAT fibrosis. More specifically, a subset of PDGFRα+ cells with high CD9 expression (CD9high) originates pro-fibrotic cells whereas their CD9low counterparts, committed to adipogenesis, are almost completely lost in the fibrotic WAT. PDGFRα pathway activation promotes a phenotypic shift toward PDGFRα+CD9high fibrogenic cells, driving pathological remodeling and altering WAT function in obesity. These findings translated to human obesity as the frequency of CD9high progenitors in omental WAT (oWAT) correlates with oWAT fibrosis level, insulin-resistance severity, and type 2 diabetes. Collectively, our data demonstrate that in addition to representing a WAT adipogenic niche, different PDGFRα+ cell subsets modulate obesity-induced WAT fibrogenesis and are associated with loss of metabolic fitness.


Assuntos
Adipócitos/patologia , Tecido Adiposo/patologia , Obesidade/metabolismo , Obesidade/patologia , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/metabolismo , Células-Tronco/metabolismo , Tetraspanina 29/metabolismo , Adipogenia , Tecido Adiposo Branco/metabolismo , Tecido Adiposo Branco/patologia , Adulto , Animais , Peso Corporal , Epididimo/metabolismo , Fibrose , Homeostase , Humanos , Resistência à Insulina , Masculino , Camundongos Endogâmicos C57BL , Obesidade/fisiopatologia , Fator de Crescimento Derivado de Plaquetas/metabolismo , Transdução de Sinais
12.
J Clin Endocrinol Metab ; 101(6): 2578-87, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27049236

RESUMO

CONTEXT: Collagen accumulation around adipocytes and vessels (ie, pericellular fibrosis) is a hallmark of obese adipose tissue associated with altered metabolism. OBJECTIVE: Our objective was to evaluate components of basement membrane (BM) in adipose tissue, including collagen IV, a major BM component, and its relationships with metabolic parameters and TGFß isoforms. DESIGN AND SETTING: We used immuno-techniques and gene expression approaches to detect BM components in subcutaneous and visceral adipose tissue samples. Adipocytes and endothelial cells were isolated from lean and obese adipose tissue. We also focused on the expression of COL4A1 correlated to metabolic variables in moderate obesity and, in severe obesity before and after bariatric surgery. Using in vitro analysis, we explored the impact of TGFß isoforms on the expression of inflammatory and extracellular matrix genes in adipocytes and endothelial cells. RESULTS: BM components were detected around adipocytes and endothelial cells, and were increased in obese adipocytes. COL4A1 expression was positively correlated with insulin-resistance indices in obese subjects and showed less reduction in severely obese subjects with poorer insulin-resistance outcomes 6 months after gastric bypass. COL4A1 expression also correlated with TGFß1 and TGFß3 gene expressions in subcutaneous adipose tissue. Stimulating isolated adipocytes and endothelial cells in vitro with these TGFß isoforms showed an inflammatory and pro-fibrotic phenotype. However, TGFß1 and TGFß3 exposure only provoked COL4A1 overexpression in endothelial cells and not in adipocytes. CONCLUSION: The disorganization of several BM components, including collagen IV, could contribute to pathological alterations of obese adipose tissue and cells.


Assuntos
Tecido Adiposo/metabolismo , Membrana Basal/metabolismo , Obesidade/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Fator de Crescimento Transformador beta3/metabolismo , Adipócitos/metabolismo , Células Cultivadas , Colágeno Tipo IV/genética , Colágeno Tipo IV/metabolismo , Células Endoteliais/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta3/genética
13.
FASEB J ; 30(1): 241-51, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26362817

RESUMO

In mice, nutritional supplementation with the trans-10,cis-12 isomer of linoleic acid (t10,c12-CLA) promotes lipoatrophy, hyperinsulinemia, and macrophage infiltration in white adipose tissue (WAT). We explored the dynamics of these interrelated responses over 2 consecutive 7 d periods of t10,c12-CLA administration and withdrawal. t10,c12-CLA down-regulated lipogenic and lipolytic gene expression and increased collagen deposition, but with no evidence of cross-linking. An abundant CD45(+) cell infiltrate, comprising prominently CD206(+)CD11c(-) macrophages, was found in WAT in association with an anti-inflammatory gene signature. Infiltration of natural killer (NK) and dendritic cells contributed to WAT's innate immune response to t10,c12-CLA. Less abundant adaptive immune cells colonized WAT, including B, NK T, γδ T, and αß T cells. By contrast, T-regulatory cell abundance was not affected. Interruption of treatment allowed recovery of WAT mass and normalization of insulinemia, coincident with regain of WAT homeostasis owing to a coordinated reversion of genic, structural, and immune deregulations. These data revealed a striking resilience of WAT after a short-term metabolic injury induced by t10,c12-CLA, which relies on alternatively activated M2 macrophage engagement. In addition, the temporal links between variations in WAT alterations and insulinemia upon t10,c12-CLA manipulation strengthen the view that WAT dysfunctional status is critically involved in altered glucose homeostasis.


Assuntos
Tecido Adiposo Branco/efeitos dos fármacos , Ácidos Linoleicos Conjugados/farmacologia , Ativação de Macrófagos , Macrófagos/efeitos dos fármacos , Adaptação Fisiológica , Tecido Adiposo Branco/citologia , Animais , Células Cultivadas , Feminino , Macrófagos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Linfócitos T/efeitos dos fármacos
14.
Diabetes ; 64(10): 3452-63, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26038578

RESUMO

Adipose tissue dysfunction in obesity has been linked to low-grade inflammation causing insulin resistance. Transcriptomic studies have identified death-associated protein kinase 2 (DAPK2) among the most strongly downregulated adipose tissue genes in human obesity, but the role of this kinase is unknown. We show that mature adipocytes rather than the stromal vascular cells in adipose tissue mainly expressed DAPK2 and that DAPK2 mRNA in obese patients gradually recovered after bariatric surgery-induced weight loss. DAPK2 mRNA is also downregulated in high-fat diet-induced obese mice. Adenoviral-mediated DAPK2 overexpression in 3T3-L1 adipocytes did not affect lipid droplet size or cell viability but did increase autophagic clearance in nutrient-rich conditions, dependent on protein kinase activity. Conversely, DAPK2 inhibition in human preadipocytes by small interfering RNA decreased LC3-II accumulation rates with lysosome inhibitors. This led us to assess autophagic clearance in adipocytes freshly isolated from subcutaneous adipose tissue of obese patients. Severe reduction in autophagic flux was observed in obese adipocytes compared with control adipocytes, inversely correlated to fat cell lipids. After bariatric surgery, adipocyte autophagic clearance partially recovered proportional to the extent of fat cell size reduction. This study links adipocyte expression of an autophagy-regulating kinase, lysosome-mediated clearance and fat cell lipid accumulation; it demonstrates obesity-related attenuated autophagy in adipocytes, and identifies DAPK2 dependence in this regulation.


Assuntos
Adipócitos/metabolismo , Autofagia/fisiologia , Proteínas Quinases Associadas com Morte Celular/metabolismo , Obesidade/metabolismo , Células 3T3-L1 , Adulto , Animais , Proteínas Quinases Associadas com Morte Celular/genética , Gorduras na Dieta , Regulação para Baixo , Feminino , Humanos , Lisossomos , Masculino , Camundongos , Camundongos Obesos , Pessoa de Meia-Idade , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
15.
Diabetes ; 64(9): 3121-34, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25695947

RESUMO

Inflammation and lipid accumulation are hallmarks of muscular pathologies resulting from metabolic diseases such as obesity and type 2 diabetes. During obesity, the hypertrophy of visceral adipose tissue (VAT) contributes to muscle dysfunction, particularly through the dysregulated production of adipokines. We have investigated the cross talk between human adipocytes and skeletal muscle cells to identify mechanisms linking adiposity and muscular dysfunctions. First, we demonstrated that the secretome of obese adipocytes decreased the expression of contractile proteins in myotubes, consequently inducing atrophy. Using a three-dimensional coculture of human myotubes and VAT adipocytes, we showed the decreased expression of genes corresponding to skeletal muscle contractility complex and myogenesis. We demonstrated an increased secretion by cocultured cells of cytokines and chemokines with interleukin (IL)-6 and IL-1ß as key contributors. Moreover, we gathered evidence showing that obese subcutaneous adipocytes were less potent than VAT adipocytes in inducing these myotube dysfunctions. Interestingly, the atrophy induced by visceral adipocytes was corrected by IGF-II/insulin growth factor binding protein-5. Finally, we observed that the skeletal muscle of obese mice displayed decreased expression of muscular markers in correlation with VAT hypertrophy and abnormal distribution of the muscle fiber size. In summary, we show the negative impact of obese adipocytes on muscle phenotype, which could contribute to muscle wasting associated with metabolic disorders.


Assuntos
Adipócitos/metabolismo , Proteínas Contráteis/metabolismo , Gordura Intra-Abdominal/citologia , Fibras Musculares Esqueléticas/metabolismo , Obesidade Mórbida/metabolismo , Adipócitos/imunologia , Adulto , Animais , Atrofia/imunologia , Atrofia/metabolismo , Técnicas de Cocultura , Citocinas/imunologia , Feminino , Regulação da Expressão Gênica , Humanos , Inflamação , Proteína 5 de Ligação a Fator de Crescimento Semelhante à Insulina/farmacologia , Fator de Crescimento Insulin-Like II/farmacologia , Interleucina-10/imunologia , Interleucina-10/metabolismo , Interleucina-1beta/imunologia , Interleucina-1beta/metabolismo , Interleucina-6/imunologia , Interleucina-6/metabolismo , Gordura Intra-Abdominal/imunologia , Gordura Intra-Abdominal/metabolismo , Masculino , Camundongos , Camundongos Obesos , Fibras Musculares Esqueléticas/imunologia , Fibras Musculares Esqueléticas/patologia , Obesidade Mórbida/imunologia , Gordura Subcutânea/citologia , Gordura Subcutânea/imunologia , Gordura Subcutânea/metabolismo , Fator de Necrose Tumoral alfa/imunologia , Fator de Necrose Tumoral alfa/metabolismo
16.
PLoS One ; 8(11): e79413, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24265769

RESUMO

Human placental development is characterized by invasion of extravillous cytotrophoblasts (EVCTs) into the uterine wall during the first trimester of pregnancy. Peroxisome proliferator-activated receptor γ (PPARγ) plays a major role in placental development, and activation of PPARγ by its agonists results in inhibition of EVCT invasion in vitro. To identify PPARγ target genes, microarray analysis was performed using GeneChip technology on EVCT primary cultures obtained from first-trimester human placentas. Gene expression was compared in EVCTs treated with the PPARγ agonist rosiglitazone versus control. A total of 139 differentially regulated genes were identified, and changes in the expression of the following 8 genes were confirmed by reverse transcription-quantitative polymerase chain reaction: a disintegrin and metalloproteinase domain12 (ADAM12), connexin 43 (CX43), deleted in liver cancer 1 (DLC1), dipeptidyl peptidase 4 (DPP4), heme oxygenase 1 (HMOX-1), lysyl oxidase (LOX), plasminogen activator inhibitor 1 (PAI-1) and PPARγ. Among the upregulated genes, lysyl oxidase (LOX) was further analyzed. In the LOX family, only LOX, LOXL1 and LOXL2 mRNA expression was significantly upregulated in rosiglitazone-treated EVCTs. RNA and protein expression of the subfamily members LOX, LOXL1 and LOXL2 were analyzed by absolute RT-qPCR and western blotting, and localized by immunohistochemistry and immunofluorescence-confocal microscopy. LOX protein was immunodetected in the EVCT cytoplasm, while LOXL1 was found in the nucleus and nucleolus. No signal was detected for LOXL2 protein. Specific inhibition of LOX activity by ß-aminopropionitrile in cell invasion assays led to an increase in EVCT invasiveness. These results suggest that LOX, LOXL1 and LOXL2 are downstream PPARγ targets and that LOX activity is a negative regulator of trophoblastic cell invasion.


Assuntos
Perfilação da Expressão Gênica , PPAR gama/metabolismo , Placentação , Proteína-Lisina 6-Oxidase/genética , Proteína-Lisina 6-Oxidase/metabolismo , Trofoblastos/citologia , Aminoácido Oxirredutases/genética , Aminoácido Oxirredutases/metabolismo , Aminopropionitrilo/farmacologia , Feminino , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Humanos , Placenta/efeitos dos fármacos , Placenta/enzimologia , Gravidez , Primeiro Trimestre da Gravidez/genética , Primeiro Trimestre da Gravidez/fisiologia , Transporte Proteico/efeitos dos fármacos , Proteína-Lisina 6-Oxidase/antagonistas & inibidores , Rosiglitazona , Tiazolidinedionas/farmacologia , Trofoblastos/efeitos dos fármacos
17.
J Clin Invest ; 123(1): 362-79, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23221346

RESUMO

Low-grade chronic inflammation is a major characteristic of obesity and results from deregulated white adipose tissue function. Consequently, there is interest in identifying the underlying regulatory mechanisms and components that drive adipocyte inflammation. Here, we report that expression of the transcriptional corepressor complex subunits GPS2 and SMRT was significantly reduced in obese adipose tissue, inversely correlated to inflammatory status, and was restored upon gastric bypass surgery-induced weight loss in morbid obesity. These alterations correlated with reduced occupancy of the corepressor complex at inflammatory promoters, providing a mechanistic explanation for elevated inflammatory transcription. In support of these correlations, RNAi-mediated depletion of GPS2 and SMRT from cultured human adipocytes promoted derepression of inflammatory transcription and elevation of obesity-associated inflammatory markers, such as IL-6 and MCP-1. Furthermore, we identified a regulatory cascade containing PPARγ and TWIST1 that controlled the expression of GPS2 and SMRT in human adipocytes. These findings were clinically relevant, because treatment of diabetic obese patients with pioglitazone, an antidiabetic and antiinflammatory PPARγ agonist, restored expression of TWIST1, GPS2, and SMRT in adipose tissue. Collectively, our findings identify alterations in a regulatory transcriptional network in adipocytes involving the dysregulation of a specific corepressor complex as among the initiating events promoting adipose tissue inflammation in human obesity.


Assuntos
Adipócitos/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Correpressor 2 de Receptor Nuclear/metabolismo , Obesidade Mórbida/metabolismo , Adipócitos/patologia , Células Cultivadas , Quimiocina CCL2/biossíntese , Quimiocina CCL2/genética , Feminino , Regulação da Expressão Gênica/genética , Humanos , Inflamação/genética , Inflamação/metabolismo , Inflamação/patologia , Interleucina-6/biossíntese , Interleucina-6/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Masculino , Proteínas Nucleares/biossíntese , Proteínas Nucleares/genética , Correpressor 2 de Receptor Nuclear/genética , Obesidade Mórbida/genética , Obesidade Mórbida/patologia , Obesidade Mórbida/cirurgia , PPAR gama/antagonistas & inibidores , PPAR gama/genética , PPAR gama/metabolismo , Transcrição Gênica/genética , Proteína 1 Relacionada a Twist/biossíntese , Proteína 1 Relacionada a Twist/genética
18.
Am J Clin Nutr ; 95(1): 49-63, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22170375

RESUMO

BACKGROUND: The most effective and safe dietary approach for weight loss and its impact on the metabolic functions and morphology of adipose tissue remain unclear. OBJECTIVES: We evaluated whether an energy-restricted high-protein diet with a low glycemic index and soluble fiber (LC-P-LGI) would be more effective than a low-calorie conventional diet (LC-CONV) on weight loss and related metabolic risk factors. We further determined factors that may influence adipocyte size during energy restriction. DESIGN: Thirteen obese participants were randomly assigned in a crossover design to 2 periods of a 4-wk hypocaloric diet as either LC-P-LGI or LC-CONV, separated by 8-wk washout intervals. RESULTS: In comparison with the LC-CONV diet, the main effect of the LC-P-LGI diet was a greater decrease in adipocyte diameter (P = 0.048), plasma plasminogen activator inhibitor protein-1 (P = 0.019), vascular endothelial growth factor (P = 0.032), and interferon-γ inducible protein 10 (P = 0.010). Whereas fasting plasma glucose and high-sensitivity C-reactive protein decreased only after the LC-P-LGI diet, with no differences between diets, fasting plasma insulin and insulin resistance were lower after the LC-CONV diet. The diet results did not differ for body composition and lipid variables. Kinetic modifications in adipocyte diameter were associated with metabolic variables and genes implicated in adipocyte proliferation, apoptosis, and angiogenesis. CONCLUSIONS: In comparison with the LC-CONV diet, the LC-P-LGI diet was associated with improvement in some cardiometabolic risk factors and greater reduction in adipocyte size. Profiles of genes involved in inhibiting adipogenesis and angiogenesis, but increasing apoptosis, were correlated with decreased adipocyte size. This study provides insight into the adipose tissue-remodeling changes that induce regulation of adipocyte size during dietary weight loss. This trial was registered at clinicaltrials.gov as NCT01312740.


Assuntos
Tecido Adiposo/patologia , Restrição Calórica , Doenças Cardiovasculares/prevenção & controle , Dieta Redutora , Carboidratos da Dieta/administração & dosagem , Proteínas Alimentares/uso terapêutico , Obesidade/dietoterapia , Adipócitos/fisiologia , Adipogenia/genética , Adipogenia/fisiologia , Tecido Adiposo/citologia , Adulto , Glicemia/metabolismo , Proteína C-Reativa/metabolismo , Quimiocina CXCL10/sangue , Estudos Cross-Over , Fibras na Dieta/administração & dosagem , Proteínas Alimentares/administração & dosagem , Proteínas Alimentares/farmacologia , Ingestão de Energia , Feminino , Expressão Gênica , Índice Glicêmico , Humanos , Insulina/sangue , Resistência à Insulina , Masculino , Pessoa de Meia-Idade , Obesidade/sangue , Obesidade/patologia , Inibidor 1 de Ativador de Plasminogênio/sangue , Fatores de Risco , Fator A de Crescimento do Endotélio Vascular , Redução de Peso/fisiologia
19.
Am J Clin Nutr ; 94(2): 450-8, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21677057

RESUMO

BACKGROUND: Obesity is considered a low-grade inflammatory state that improves with weight loss. In addition to acute-phase proteins, other cytokines might contribute to systemic inflammation. OBJECTIVE: Our objective was to compare serum concentrations of a large panel of inflammation-related factors in obese and normal-weight subjects and to determine kinetic changes induced by caloric restriction. DESIGN: The cohort comprised 14 normal-weight women and 51 obese women who were followed over 2 y after Roux-en-Y gastric bypass. Multiplexed proteomics were used to simultaneously assay 27 cytokines and growth factors in serum. RESULTS: Concentrations of interleukin (IL)-9, IL-1-receptor antagonist, IL-10, interferon-γ-inducible protein 10, macrophage inflammatory protein 1ß, monocyte chemoattractant protein 1, IL-8, RANTES (regulated upon activation, normal T cell expressed and secreted), monokine induced by interferon-γ, and vascular endothelial growth factor were found to be elevated in obesity. IL-10 was further elevated in diabetic obese patients, whereas eotaxin was found to be higher only in diabetic subjects. After surgery, many factors showed a biphasic pattern of variation, decreasing sharply at month 3 before rising back to presurgical values at month 6; these changes closely tracked similar kinetic changes in calorie and carbohydrate intake. After 1 y, an overall reduction in cytokines accompanied the reduction in body mass index and an amelioration in metabolic status. CONCLUSIONS: Obesity is associated with elevated circulating concentrations of a large panel of cytokines. Coordinated kinetic changes during weight loss suggest an early influence of calorie and carbohydrate intakes, whereas a longer-term reduction in corpulence might prevail in regulating circulating cytokine concentrations. This trial is registered at clincaltrials.gov as NCT00476658.


Assuntos
Citocinas/sangue , Carboidratos da Dieta/administração & dosagem , Ingestão de Energia , Obesidade/imunologia , Procedimentos Cirúrgicos Operatórios , Redução de Peso , Adulto , Diabetes Mellitus Tipo 2/imunologia , Feminino , Derivação Gástrica , Humanos , Pessoa de Meia-Idade , Obesidade/cirurgia
20.
Obes Facts ; 4(1): 17-25, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21372607

RESUMO

OBJECTIVE: At present, circulating markers characterizing the inflammatory infiltration of white adipose tissue (WAT) in human obesity are not well known. We previously identified, by a pangenomic approach (microarrays), the urokinase plasminogen activator receptor (PLAUR or CD87) as a potential marker of subcutaneous adipose tissue macrophage infiltration (ATM). METHOD: We studied i) the presence of PLAUR protein in WAT; ii) the PLAUR amount in plasma of obese patients; iii) the circulating variations during surgery-induced weight loss, and iv) the correlations between PLAUR circulating levels and bioclinical parameters. RESULTS: We observed that PLAUR is preferentially expressed by infiltrating ATMs, with a typical localization on macrophage membrane. Circulating soluble PLAUR levels were significantly elevated in obese patients compared to lean controls. However, despite a trend towards a decrease 3 months after weight loss, PLAUR plasma levels were not modulated during a 1-year weight loss follow-up, suggesting the contribution of secretion sites other than subcutaneous WAT in obese patients. CONCLUSIONS: These findings indicate that PLAUR mRNA expression could be used for the estimation of local subcutaneous ATMs infiltration in obese patients, but it cannot be used as a systemic marker of this inflammatory infiltration in dynamic phases of weight loss.


Assuntos
Tecido Adiposo Branco/imunologia , Inflamação/patologia , Macrófagos/patologia , Obesidade Mórbida/patologia , Receptores de Ativador de Plasminogênio Tipo Uroquinase/metabolismo , Tecido Adiposo Branco/metabolismo , Tecido Adiposo Branco/patologia , Adulto , Biomarcadores/análise , Feminino , Humanos , Macrófagos/imunologia , Macrófagos/metabolismo , Obesidade Mórbida/imunologia , Obesidade Mórbida/metabolismo
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