Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 76
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
2.
Matrix Biol ; 102: 37-69, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34508852

RESUMO

Dysregulation of proteolytic enzymes has huge impact on epidermal homeostasis, which can result in severe pathological conditions such as fibrosis or Netherton syndrome. The metalloprotease meprin ß was found to be upregulated in hyperproliferative skin diseases. AP-1 transcription factor complex has been reported to induce Mep1b expression. Since AP-1 and its subunit fos-related antigen 2 (fra-2) are associated with the onset and progression of psoriasis, we wanted to investigate if this could partially be attributed to increased meprin ß activity. Here, we demonstrate that fra-2 transgenic mice show increased meprin ß expression and proteolytic activity in the epidermis. To avoid influence by other fra-2 regulated genes, we additionally generated a mouse model that enabled tamoxifen-inducible expression of meprin ß under the Krt5-promotor to mimic the pathological condition. Interestingly, induced meprin ß expression in the epidermis resulted in hyperkeratosis, hair loss and mottled pigmentation of the skin. Employing N-terminomics revealed syndecan-1 as a substrate of meprin ß in skin. Shedding of syndecan-1 at the cell surface caused delayed calcium-induced differentiation and impaired adhesion of keratinocytes, which was blocked by the meprin ß inhibitor fetuin-B.

3.
Nat Commun ; 12(1): 5249, 2021 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-34475397

RESUMO

The wake-active orexin system plays a central role in the dynamic regulation of glucose homeostasis. Here we show orexin receptor type 1 and 2 are predominantly expressed in dorsal raphe nucleus-dorsal and -ventral, respectively. Serotonergic neurons in ventral median raphe nucleus and raphe pallidus selectively express orexin receptor type 1. Inactivation of orexin receptor type 1 in serotonin transporter-expressing cells of mice reduced insulin sensitivity in diet-induced obesity, mainly by decreasing glucose utilization in brown adipose tissue and skeletal muscle. Selective inactivation of orexin receptor type 2 improved glucose tolerance and insulin sensitivity in obese mice, mainly through a decrease in hepatic gluconeogenesis. Optogenetic activation of orexin neurons in lateral hypothalamus or orexinergic fibers innervating raphe pallidus impaired or improved glucose tolerance, respectively. Collectively, the present study assigns orexin signaling in serotonergic neurons critical, yet differential orexin receptor type 1- and 2-dependent functions in the regulation of systemic glucose homeostasis.


Assuntos
Glucose/metabolismo , Obesidade/metabolismo , Receptores de Orexina/metabolismo , Neurônios Serotoninérgicos/metabolismo , Tecido Adiposo Marrom/metabolismo , Animais , Dieta Hiperlipídica/efeitos adversos , Homeostase , Região Hipotalâmica Lateral/citologia , Região Hipotalâmica Lateral/metabolismo , Resistência à Insulina , Fígado/metabolismo , Camundongos , Fibras Nervosas/metabolismo , Obesidade/etiologia , Receptores de Orexina/genética , Orexinas/metabolismo , Núcleos da Rafe/metabolismo , Proteínas da Membrana Plasmática de Transporte de Serotonina/genética , Proteínas da Membrana Plasmática de Transporte de Serotonina/metabolismo , Transdução de Sinais
4.
Cell Metab ; 33(7): 1466-1482.e7, 2021 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-34043943

RESUMO

Sensory neurons relay gut-derived signals to the brain, yet the molecular and functional organization of distinct populations remains unclear. Here, we employed intersectional genetic manipulations to probe the feeding and glucoregulatory function of distinct sensory neurons. We reconstruct the gut innervation patterns of numerous molecularly defined vagal and spinal afferents and identify their downstream brain targets. Bidirectional chemogenetic manipulations, coupled with behavioral and circuit mapping analysis, demonstrated that gut-innervating, glucagon-like peptide 1 receptor (GLP1R)-expressing vagal afferents relay anorexigenic signals to parabrachial nucleus neurons that control meal termination. Moreover, GLP1R vagal afferent activation improves glucose tolerance, and their inhibition elevates blood glucose levels independent of food intake. In contrast, gut-innervating, GPR65-expressing vagal afferent stimulation increases hepatic glucose production and activates parabrachial neurons that control normoglycemia, but they are dispensable for feeding regulation. Thus, distinct gut-innervating sensory neurons differentially control feeding and glucoregulatory neurocircuits and may provide specific targets for metabolic control.

5.
Blood ; 137(5): 646-660, 2021 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-33538798

RESUMO

Richter's transformation (RT) is an aggressive lymphoma that occurs upon progression from chronic lymphocytic leukemia (CLL). Transformation has been associated with genetic aberrations in the CLL phase involving TP53, CDKN2A, MYC, and NOTCH1; however, a significant proportion of RT cases lack CLL phase-associated events. Here, we report that high levels of AKT phosphorylation occur both in high-risk CLL patients harboring TP53 and NOTCH1 mutations as well as in patients with RT. Genetic overactivation of Akt in the murine Eµ-TCL1 CLL mouse model resulted in CLL transformation to RT with significantly reduced survival and an aggressive lymphoma phenotype. In the absence of recurrent mutations, we identified a profile of genomic aberrations intermediate between CLL and diffuse large B-cell lymphoma. Multiomics assessment by phosphoproteomic/proteomic and single-cell transcriptomic profiles of this Akt-induced murine RT revealed an S100 protein-defined subcluster of highly aggressive lymphoma cells that developed from CLL cells, through activation of Notch via Notch ligand expressed by T cells. Constitutively active Notch1 similarly induced RT of murine CLL. We identify Akt activation as an initiator of CLL transformation toward aggressive lymphoma by inducing Notch signaling between RT cells and microenvironmental T cells.


Assuntos
Leucemia Linfocítica Crônica de Células B/patologia , Linfoma Difuso de Grandes Células B/patologia , Proteínas de Neoplasias/fisiologia , Proteínas Proto-Oncogênicas c-akt/fisiologia , Receptor Notch1/fisiologia , Animais , Evolução Clonal , Progressão da Doença , Ativação Enzimática , Regulação Neoplásica da Expressão Gênica , Genes p53 , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/fisiopatologia , Linfócitos do Interstício Tumoral/imunologia , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/fisiopatologia , Camundongos , Camundongos Endogâmicos C57BL , Fenótipo , Fosfoproteínas/fisiologia , Proteínas Proto-Oncogênicas c-akt/genética , Receptores de Antígenos de Linfócitos B/imunologia , Transdução de Sinais/fisiologia , Transcriptoma , Microambiente Tumoral , Proteína Supressora de Tumor p53/fisiologia , Regulação para Cima
6.
Blood ; 2020 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-33140819

RESUMO

Richter's transformation (RT) is an aggressive lymphoma which occurs upon progression from chronic lymphocytic leukemia (CLL). Transformation has been associated with genetic aberrations in the CLL-phase involving TP53, CDKN2A, MYC, and NOTCH1, however a significant proportion of RT cases lack CLL-phase associated events. Here, we report that high levels of AKT phosphorylation occurs both in high-risk CLL patients harboring TP53 and NOTCH1 mutations as well as in RT patients. Genetic over-activation of Akt in the murine Eµ-TCL1 CLL mouse model resulted in CLL to RT with significantly reduced survival and an aggressive lymphoma phenotype. In the absence of recurrent mutations, we identified a profile of genomic aberrations intermediate between CLL and DLBCL. Multi-omics assessment by phosphoproteomic/proteomic and single-cell transcriptomic profiles of this Akt-induced murine RT revealed a S100-protein-defined subcluster of highly aggressive lymphoma cells, which developed from CLL cells, through activation of Notch via Notch ligand expressed by T cells. Constitutively active Notch1 similarly induced RT of murine CLL. We identify Akt activation as an initiator of CLL transformation towards aggressive lymphoma by inducing Notch signaling between RT cells and microenvironmental T cells.

7.
Mol Metab ; 42: 101085, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32956847

RESUMO

OBJECTIVE: Single-nucleotide polymorphisms in the FTO gene encoding an m6Am and an m6A demethylase are associated with obesity. Moreover, recent studies have linked a dysregulation of m6A modifications and its machinery, including FTO, to the development of several forms of cancers. However, the functional role of hepatic FTO in metabolism and the development and progression of hepatocellular carcinoma (HCC), a proteotypic obesity-associated cancer, remains unclear. Thus, we aimed to reveal the role of hepatic FTO in metabolism and in the initiation and progression of HCC in vivo. METHODS: We generated mice with hepatic FTO deficiency (FTOL-KO). The effect of hepatic FTO on metabolism was investigated by extensive metabolic phenotyping. To determine the impact of hepatic FTO on HCC development, FTOL-KO and Ctrl mice were subjected to long-term diethylnitrosamine (DEN)-induced HCC-development and the tumor initiation phase was examined via a short-term DEN protocol. RESULTS: In long-term DEN experiments, FTOL-KO mice exhibit increased HCC burden compared to Ctrl mice. In the tumor initiation phase, Ctrl mice display a dynamic regulation of FTO upon induction of liver damage, while this response is abrogated in FTO-deficient mice. Proteomic analyses revealed that liver damage-induced increases in FTO expression reduce CUL4A protein abundance. Functionally, simultaneous knockdown of Cul4a reverses the increased hepatocyte proliferation observed upon loss of FTO. CONCLUSION: Collectively, our study demonstrates that hepatic FTO is dispensable for the control of energy homeostasis and glucose metabolism. However, we show a protective function of FTO in liver carcinogenesis and suggest the FTO-dependent dynamic mRNA demethylation of Cul4a in the initiation of HCC development contributes to this effect.


Assuntos
Dioxigenase FTO Dependente de alfa-Cetoglutarato/genética , Glucose/metabolismo , Dioxigenase FTO Dependente de alfa-Cetoglutarato/metabolismo , Animais , Carcinoma Hepatocelular/metabolismo , Proliferação de Células/genética , Metabolismo Energético , Homeostase , Fígado/fisiologia , Neoplasias Hepáticas/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Polimorfismo de Nucleotídeo Único/genética , Proteômica/métodos , Transdução de Sinais/genética
8.
Neuron ; 106(6): 1009-1025.e10, 2020 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-32302532

RESUMO

Calorie-rich diets induce hyperphagia and promote obesity, although the underlying mechanisms remain poorly defined. We find that short-term high-fat-diet (HFD) feeding of mice activates prepronociceptin (PNOC)-expressing neurons in the arcuate nucleus of the hypothalamus (ARC). PNOCARC neurons represent a previously unrecognized GABAergic population of ARC neurons distinct from well-defined feeding regulatory AgRP or POMC neurons. PNOCARC neurons arborize densely in the ARC and provide inhibitory synaptic input to nearby anorexigenic POMC neurons. Optogenetic activation of PNOCARC neurons in the ARC and their projections to the bed nucleus of the stria terminalis promotes feeding. Selective ablation of these cells promotes the activation of POMC neurons upon HFD exposure, reduces feeding, and protects from obesity, but it does not affect food intake or body weight under normal chow consumption. We characterize PNOCARC neurons as a novel ARC neuron population activated upon palatable food consumption to promote hyperphagia.


Assuntos
Núcleo Arqueado do Hipotálamo/fisiologia , Dieta Hiperlipídica , Comportamento Alimentar/fisiologia , Neurônios GABAérgicos/fisiologia , Hiperfagia , Obesidade , Ganho de Peso/fisiologia , Animais , Núcleo Arqueado do Hipotálamo/citologia , Núcleo Arqueado do Hipotálamo/metabolismo , Neurônios GABAérgicos/metabolismo , Camundongos , Inibição Neural/fisiologia , Neurônios/metabolismo , Neurônios/fisiologia , Optogenética , Pró-Opiomelanocortina/metabolismo , Precursores de Proteínas/metabolismo , Receptores Opioides/metabolismo , Núcleos Septais/fisiologia
9.
J Immunol ; 204(12): 3217-3226, 2020 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-32341061

RESUMO

The glycoprotein CD83 is known to be expressed by different immune cells including activated CD4+Foxp3+ regulatory T cells (Tregs) and CD4+Foxp3- conventional T cells. However, the physiological function of endogenous CD83 in CD4+ T cell subsets is still unclear. In this study, we have generated a new CD83flox mouse line on BALB/c background, allowing for specific ablation of CD83 in T cells upon breeding with CD4-cre mice. Tregs from CD83flox/flox/CD4-cretg/wt mice had similar suppressive activity as Tregs from CD83flox/flox/CD4-crewt/wt wild-type littermates, suggesting that endogenous CD83 expression is dispensable for the inhibitory capacity of Tregs. However, CD83-deficient CD4+ conventional T cells showed elevated proliferation and IFN-γ secretion as well as an enhanced capacity to differentiate into Th1 cells and Th17 cells upon stimulation in vitro. T cell-specific ablation of CD83 expression resulted in aggravated contact hypersensitivity reaction accompanied by enhanced CD4+ T cell activation. Moreover, adoptive transfer of CD4+CD45RBhigh T cells from CD83flox/flox/CD4-cretg /wt mice into Rag2-deficient mice elicited more severe colitis associated with increased serum concentrations of IL-12 and elevated CD40 expression on CD11c+ dendritic cells (DCs). Strikingly, DCs from BALB/c mice cocultured with CD83-deficient CD4+ conventional T cells showed enhanced CD40 expression and IL-12 secretion compared with DCs cocultured with CD4+ conventional T cells from CD83flox/flox/CD4-crewt/wt wild-type mice. In summary, these results indicate that endogenous CD83 expression in CD4+ conventional T cells plays a crucial role in controlling CD4+ T cell responses, at least in part, by regulating the activity of CD11c+ DCs.


Assuntos
Antígenos CD/imunologia , Linfócitos T CD4-Positivos/imunologia , Imunidade/imunologia , Imunoglobulinas/imunologia , Inflamação/imunologia , Glicoproteínas de Membrana/imunologia , Transferência Adotiva/métodos , Animais , Células Dendríticas/imunologia , Feminino , Interferon gama/imunologia , Interleucina-12/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Linfócitos T Reguladores/imunologia , Células Th1/imunologia , Células Th17/imunologia
10.
J Immunol ; 204(4): 747-751, 2020 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-31924653

RESUMO

IL-6 binds to the IL-6R α-chain (IL-6Rα) and signals via the signal transducer gp130. Recently, IL-6 was found to also bind to the cell surface glycoprotein CD5, which would then engage gp130 in the absence of IL-6Rα. However, the biological relevance of this alternative pathway is under debate. In this study, we developed a mouse model, in which murine IL-6 is overexpressed in a CD11c-Cre-dependent manner. Transgenic mice developed a lethal immune dysregulation syndrome with increased numbers of Ly-6G+ neutrophils and Ly-6Chi monocytes/macrophages. IL-6 overexpression promoted activation of CD4+ T cells while suppressing CD5+ B-1a cell development. However, additional ablation of IL-6Rα protected IL-6-overexpressing mice from IL-6-triggered inflammation and fully phenocopied IL-6Rα-deficient mice without IL-6 overexpression. Mechanistically, IL-6Rα deficiency completely prevented downstream activation of STAT3 in response to IL-6. Altogether, our data clarify that IL-6Rα is the only biologically relevant receptor for IL-6 in mice.


Assuntos
Interleucina-6/imunologia , Receptores de Interleucina-6/imunologia , Transdução de Sinais/imunologia , Animais , Camundongos , Camundongos Transgênicos
11.
Immunity ; 50(5): 1232-1248.e14, 2019 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-31027998

RESUMO

Regulatory T cells (Treg cells) are important for preventing autoimmunity and maintaining tissue homeostasis, but whether Treg cells can adopt tissue- or immune-context-specific suppressive mechanisms is unclear. Here, we found that the enzyme hydroxyprostaglandin dehydrogenase (HPGD), which catabolizes prostaglandin E2 (PGE2) into the metabolite 15-keto PGE2, was highly expressed in Treg cells, particularly those in visceral adipose tissue (VAT). Nuclear receptor peroxisome proliferator-activated receptor-γ (PPARγ)-induced HPGD expression in VAT Treg cells, and consequential Treg-cell-mediated generation of 15-keto PGE2 suppressed conventional T cell activation and proliferation. Conditional deletion of Hpgd in mouse Treg cells resulted in the accumulation of functionally impaired Treg cells specifically in VAT, causing local inflammation and systemic insulin resistance. Consistent with this mechanism, humans with type 2 diabetes showed decreased HPGD expression in Treg cells. These data indicate that HPGD-mediated suppression is a tissue- and context-dependent suppressive mechanism used by Treg cells to maintain adipose tissue homeostasis.


Assuntos
Dinoprostona/análogos & derivados , Dinoprostona/metabolismo , Hidroxiprostaglandina Desidrogenases/metabolismo , Gordura Intra-Abdominal/imunologia , Linfócitos T Reguladores/enzimologia , Linfócitos T Reguladores/imunologia , Células 3T3 , Animais , Linhagem Celular , Diabetes Mellitus Tipo 2/metabolismo , Células HEK293 , Homeostase/imunologia , Humanos , Hidroxiprostaglandina Desidrogenases/genética , Resistência à Insulina/genética , Gordura Intra-Abdominal/citologia , Células Jurkat , Ativação Linfocitária/imunologia , Masculino , Camundongos , Camundongos Knockout , Fator de Transcrição STAT5/metabolismo
12.
Cancers (Basel) ; 11(1)2018 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-30591653

RESUMO

Obesity promotes the development of numerous cancers, such as liver and colorectal cancers, which is at least partly due to obesity-induced, chronic, low-grade inflammation. In particular, the recruitment and activation of immune cell subsets in the white adipose tissue systemically increase proinflammatory cytokines, such as tumor necrosis factor α (TNFα) and interleukin-6 (IL-6). These proinflammatory cytokines not only impair insulin action in metabolic tissues, but also favor cancer development. Here, we review the current state of knowledge on how obesity affects inflammatory TNFα and IL-6 signaling in hepatocellular carcinoma and colorectal cancers.

13.
Mol Metab ; 17: 122-133, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30224299

RESUMO

OBJECTIVE: The current obesity pandemic represents a major health burden, given that it predisposes to the development of numerous obesity-associated disorders. The obesity-derived adipokines not only impair systemic insulin action but also increase the incidence of hepatocellular carcinoma (HCC), a highly prevalent cancer with poor prognosis. Thus, worldwide incidences of HCC are expected to further increase, and defining the molecular as well as cellular mechanisms will allow for establishing new potential treatment options. The adipose tissue of obese individuals increases circulating leptin and interleukin-6 (IL-6) levels, which both share similar signaling capacities such as Signal Transducer and Activator of Transcription 3 (STAT3) and Phosphoinositide 3-kinase (PI3K)/Akt activation. While mouse models with deficient IL-6 signaling show an ameliorated but not absent Diethylnitrosamine (DEN)-induced HCC development, the morbid obesity in mice with mutant leptin signaling complicates the dissection of hepatic leptin receptor (LEPR) and IL-6 signaling in HCC development. Here we have investigated the function of compensating hepatic LEPR expression in HCC development of IL-6Rα-deficient mice. METHODS: We generated and characterized a mouse model of hepatic LEPR deficiency that was intercrossed with IL-6Rα-deficient mice. Cohorts of single and double knockout mice were subjected to the DEN-HCC model to ascertain liver cancer development and characterize metabolic alterations. RESULTS: We demonstrate that both high-fat diet (HFD)-induced obesity and IL-6Rα deficiency induce hepatic Lepr expression. Consistently, double knockout mice show a further reduction in tumor burden in DEN-induced HCC when compared to control and single LepRL-KO/IL-6Rα knock out mice, whereas metabolism remained largely unaltered between the genotypes. CONCLUSIONS: Our findings reveal a compensatory role for hepatic LEPR in HCC development of IL-6Rα-deficient mice and suggest hepatocyte-specific leptin signaling as promoter of HCC under obese conditions.


Assuntos
Subunidade alfa de Receptor de Interleucina-6/deficiência , Neoplasias Hepáticas Experimentais/metabolismo , Receptores para Leptina/biossíntese , Animais , Proliferação de Células/fisiologia , Dieta Hiperlipídica , Dietilnitrosamina , Modelos Animais de Doenças , Feminino , Expressão Gênica , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Hepatócitos/patologia , Subunidade alfa de Receptor de Interleucina-6/genética , Subunidade alfa de Receptor de Interleucina-6/metabolismo , Leptina/metabolismo , Metabolismo dos Lipídeos , Neoplasias Hepáticas Experimentais/induzido quimicamente , Neoplasias Hepáticas Experimentais/genética , Neoplasias Hepáticas Experimentais/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Receptores para Leptina/genética , Receptores para Leptina/metabolismo , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais
14.
Exp Mol Med ; 50(6): 1-17, 2018 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-29959317

RESUMO

Ciliopathies comprise a large number of hereditary human diseases and syndromes caused by mutations resulting in dysfunction of either primary or motile cilia. Both types of cilia share a similar architecture. While primary cilia are present on most cell types, expression of motile cilia is limited to specialized tissues utilizing ciliary motility. We characterized protein complexes of ciliopathy proteins and identified the conserved AAA-ATPase Ruvbl1 as a common novel component. Here, we demonstrate that Ruvbl1 is crucial for the development and maintenance of renal tubular epithelium in mice: both constitutive and inducible deletion in tubular epithelial cells result in renal failure with tubular dilatations and fewer ciliated cells. Moreover, inducible deletion of Ruvbl1 in cells carrying motile cilia results in hydrocephalus, suggesting functional relevance in both primary and motile cilia. Cilia of Ruvbl1-negative cells lack crucial proteins, consistent with the concept of Ruvbl1-dependent cytoplasmic pre-assembly of ciliary protein complexes.


Assuntos
ATPases Associadas a Diversas Atividades Celulares/deficiência , Ciliopatias , DNA Helicases/deficiência , Deleção de Genes , Hidrocefalia , Nefropatias , Animais , Cílios/genética , Cílios/metabolismo , Ciliopatias/genética , Ciliopatias/metabolismo , Ciliopatias/patologia , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Hidrocefalia/genética , Hidrocefalia/metabolismo , Hidrocefalia/patologia , Nefropatias/genética , Nefropatias/metabolismo , Nefropatias/patologia , Túbulos Renais/metabolismo , Túbulos Renais/patologia , Camundongos , Camundongos Transgênicos
15.
Nat Commun ; 9(1): 1646, 2018 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-29695802

RESUMO

Colorectal cancer (CRC) is one of the most lethal cancers worldwide in which the vast majority of cases exhibit little genetic risk but are associated with a sedentary lifestyle and obesity. Although the mechanisms underlying CRC and colitis-associated colorectal cancer (CAC) remain unclear, we hypothesised that obesity-induced inflammation predisposes to CAC development. Here, we show that diet-induced obesity accelerates chemically-induced CAC in mice via increased inflammation and immune cell recruitment. Obesity-induced interleukin-6 (IL-6) shifts macrophage polarisation towards tumour-promoting macrophages that produce the chemokine CC-chemokine-ligand-20 (CCL-20) in the CAC microenvironment. CCL-20 promotes CAC progression by recruiting CC-chemokine-receptor-6 (CCR-6)-expressing B cells and γδ T cells via chemotaxis. Compromised cell recruitment as well as inhibition of B and γδ T cells protects against CAC progression. Collectively, our data reveal a function for IL-6 in the CAC microenvironment via lymphocyte recruitment through the CCL-20/CCR-6 axis, thereby implicating a potential therapeutic intervention for human patients.


Assuntos
Quimiocina CCL20/metabolismo , Colite Ulcerativa/patologia , Neoplasias Colorretais/imunologia , Interleucina-6/metabolismo , Obesidade/imunologia , Receptores CCR6/metabolismo , Animais , Transformação Celular Neoplásica/imunologia , Transformação Celular Neoplásica/patologia , Quimiocina CCL20/imunologia , Quimiotaxia/imunologia , Colite Ulcerativa/induzido quimicamente , Colite Ulcerativa/imunologia , Colo/efeitos dos fármacos , Colo/imunologia , Colo/patologia , Neoplasias Colorretais/patologia , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Progressão da Doença , Feminino , Humanos , Subunidade alfa de Receptor de Interleucina-6/genética , Subunidade alfa de Receptor de Interleucina-6/metabolismo , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/imunologia , Mucosa Intestinal/patologia , Linfócitos/imunologia , Linfócitos/metabolismo , Macrófagos/imunologia , Macrófagos/metabolismo , Camundongos , Camundongos Knockout , Obesidade/etiologia , Receptores CCR6/genética , Transdução de Sinais/imunologia , Microambiente Tumoral/imunologia
16.
Nat Med ; 23(12): 1466-1473, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29106399

RESUMO

Over 40% of microRNAs (miRNAs) are located in introns of protein-coding genes, and many of these intronic miRNAs are co-regulated with their host genes. In such cases of co-regulation, the products of host genes and their intronic miRNAs can cooperate to coordinately regulate biologically important pathways. Therefore, we screened intronic miRNAs dysregulated in the livers of mouse models of obesity to identify previously uncharacterized protein-coding host genes that may contribute to the pathogenesis of obesity-associated insulin resistance and type 2 diabetes mellitus. Our approach revealed that expression of both the gene encoding ectodysplasin A (Eda), the causal gene in X-linked hypohidrotic ectodermal dysplasia (XLHED), and its intronic miRNA, miR-676, was increased in the livers of obese mice. Moreover, hepatic EDA expression is increased in obese human subjects and reduced upon weight loss, and its hepatic expression correlates with systemic insulin resistance. We also found that reducing miR-676 expression in db/db mice increases the expression of proteins involved in fatty acid oxidation and reduces the expression of inflammatory signaling components in the liver. Further, we found that Eda expression in mouse liver is controlled via PPARγ and RXR-α, increases in circulation under conditions of obesity, and promotes JNK activation and inhibitory serine phosphorylation of IRS1 in skeletal muscle. In accordance with these findings, gain- and loss-of-function approaches reveal that liver-derived EDA regulates systemic glucose metabolism, suggesting that EDA is a hepatokine that can contribute to impaired skeletal muscle insulin sensitivity in obesity.


Assuntos
Ectodisplasinas/genética , Resistência à Insulina/genética , Fígado/metabolismo , MicroRNAs/genética , Músculo Esquelético/metabolismo , Obesidade/genética , Animais , Células Cultivadas , Displasia Ectodérmica Anidrótica Tipo 1/genética , Ectodisplasinas/metabolismo , Perfilação da Expressão Gênica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Camundongos Obesos , Camundongos Transgênicos , Obesidade/metabolismo
18.
Nat Commun ; 8(1): 153, 2017 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-28751718

RESUMO

Chronic lymphocytic leukemia (CLL) remains an incurable disease. Two recurrent cytogenetic aberrations, namely del(17p), affecting TP53, and del(11q), affecting ATM, are associated with resistance against genotoxic chemotherapy (del17p) and poor outcome (del11q and del17p). Both del(17p) and del(11q) are also associated with inferior outcome to the novel targeted agents, such as the BTK inhibitor ibrutinib. Thus, even in the era of targeted therapies, CLL with alterations in the ATM/p53 pathway remains a clinical challenge. Here we generated two mouse models of Atm- and Trp53-deficient CLL. These animals display a significantly earlier disease onset and reduced overall survival, compared to controls. We employed these models in conjunction with transcriptome analyses following cyclophosphamide treatment to reveal that Atm deficiency is associated with an exquisite and genotype-specific sensitivity against PARP inhibition. Thus, we generate two aggressive CLL models and provide a preclinical rational for the use of PARP inhibitors in ATM-affected human CLL.ATM and TP53 mutations are associated with poor prognosis in chronic lymphocytic leukaemia (CLL). Here the authors generate mouse models of Tp53- and Atm-defective CLL mimicking the high-risk form of human disease and show that Atm-deficient CLL is sensitive to PARP1 inhibition.


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Modelos Animais de Doenças , Leucemia Linfocítica Crônica de Células B/metabolismo , Poli(ADP-Ribose) Polimerase-1/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Proteínas Mutadas de Ataxia Telangiectasia/genética , Deleção Cromossômica , Cromossomos Humanos Par 11/genética , Cromossomos Humanos Par 17/genética , Ciclofosfamida/farmacologia , Perfilação da Expressão Gênica/métodos , Humanos , Immunoblotting , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Leucemia Linfocítica Crônica de Células B/genética , Camundongos Endogâmicos C57BL , Camundongos Knockout , Poli(ADP-Ribose) Polimerase-1/antagonistas & inibidores , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Análise de Sobrevida , Proteína Supressora de Tumor p53/genética
19.
Cell Metab ; 26(1): 171-184.e6, 2017 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-28683285

RESUMO

Natural killer (NK) cells contribute to the development of obesity-associated insulin resistance. We demonstrate that in mice obesity promotes expansion of a distinct, interleukin-6 receptor (IL6R)a-expressing NK subpopulation, which also expresses a number of other myeloid lineage genes such as the colony-stimulating factor 1 receptor (Csf1r). Selective ablation of this Csf1r-expressing NK cell population prevents obesity and insulin resistance. Moreover, conditional inactivation of IL6Ra or Stat3 in NK cells limits obesity-associated formation of these myeloid signature NK cells, protecting from obesity, insulin resistance, and obesity-associated inflammation. Also in humans IL6Ra+ NK cells increase in obesity and correlate with markers of systemic low-grade inflammation, and their gene expression profile overlaps with characteristic gene sets of NK cells in obese mice. Collectively, we demonstrate that obesity-associated inflammation and metabolic disturbances depend on interleukin-6/Stat3-dependent formation of a distinct NK population, which may provide a target for the treatment of obesity, metaflammation-associated pathologies, and diabetes.


Assuntos
Metabolismo Energético , Glucose/metabolismo , Inflamação/metabolismo , Interleucina-6/metabolismo , Células Matadoras Naturais/patologia , Obesidade/metabolismo , Fator de Transcrição STAT3/metabolismo , Adulto , Animais , Homeostase , Humanos , Inflamação/complicações , Inflamação/patologia , Resistência à Insulina , Células Matadoras Naturais/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Obesidade/complicações , Obesidade/patologia , Receptores de Fator Estimulador das Colônias de Granulócitos e Macrófagos/metabolismo , Receptores de Interleucina-6/metabolismo , Transdução de Sinais , Adulto Jovem
20.
Nat Commun ; 8: 14803, 2017 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-28466852

RESUMO

Low-grade inflammation links obesity to insulin resistance through the activation of tissue-infiltrating immune cells. Interleukin-6 (IL-6) is a crucial regulator of T cells and is increased in obesity. Here we report that classical IL-6 signalling in T cells promotes inflammation and insulin resistance during the first 8 weeks on a high-fat diet (HFD), but becomes dispensable at later stages (after 16 weeks). Mice with T cell-specific deficiency of IL-6 receptor-α (IL-6RαT-KO) exposed to a HFD display improved glucose tolerance, insulin sensitivity and inflammation in liver and EWAT after 8 weeks. However, after 16 weeks, insulin resistance in IL-6RαT-KO epididymal white adipose tissue (EWAT) is comparable to that of controls, whereas the inflammatory profile is significantly worse. This coincided with a shift from classical T cell IL-6 signalling at 8 weeks, to enhanced IL-6 trans-signalling at 16 weeks. Collectively, our studies reveal that IL-6 action in T cells through classical IL-6 signalling promotes inflammation and insulin resistance early during obesity development, which can be compensated for by enhanced IL-6 trans-signalling at later stages.


Assuntos
Inflamação/metabolismo , Resistência à Insulina , Interleucina-6/metabolismo , Obesidade/metabolismo , Transdução de Sinais , Linfócitos T/metabolismo , Animais , Glicemia/metabolismo , Dieta Hiperlipídica , Homeostase , Interleucina-6/genética , Metabolismo dos Lipídeos , Masculino , Camundongos , Camundongos Knockout , Receptores de Interleucina-6/genética , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...