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1.
Front Immunol ; 12: 650856, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34211460

RESUMO

Accumulating evidence suggests that cholesterol accumulation in leukocytes is causally associated with the development of autoimmune diseases. However, the mechanism by which fatty acid composition influences autoimmune responses remains unclear. To determine whether the fatty acid composition of diet modulates leukocyte function and the development of systemic lupus erythematosus, we examined the effect of eicosapentaenoic acid (EPA) on the pathology of lupus in drug-induced and spontaneous mouse models. We found that dietary EPA supplementation ameliorated representative lupus manifestations, including autoantibody production and immunocomplex deposition in the kidneys. A combination of lipidomic and membrane dynamics analyses revealed that EPA remodels the lipid composition and fluidity of B cell membranes, thereby preventing B cell differentiation into autoantibody-producing plasma cells. These results highlight a previously unrecognized mechanism by which fatty acid composition affects B cell differentiation into autoantibody-producing plasma cells during autoimmunity, and imply that EPA supplementation may be beneficial for therapy of lupus.


Assuntos
Autoimunidade/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Suplementos Nutricionais , Ácido Eicosapentaenoico/farmacologia , Lúpus Eritematoso Sistêmico/prevenção & controle , Plasmócitos/efeitos dos fármacos , Animais , Autoanticorpos/imunologia , Autoanticorpos/metabolismo , Autoimunidade/imunologia , Linfócitos B/efeitos dos fármacos , Linfócitos B/imunologia , Linfócitos B/metabolismo , Diferenciação Celular/imunologia , Células Cultivadas , Modelos Animais de Doenças , Ácido Eicosapentaenoico/administração & dosagem , Feminino , Rim/efeitos dos fármacos , Rim/imunologia , Rim/patologia , Lúpus Eritematoso Sistêmico/imunologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Plasmócitos/imunologia , Plasmócitos/metabolismo
2.
Nature ; 595(7866): 266-271, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34163066

RESUMO

Obesity is a worldwide epidemic that predisposes individuals to many age-associated diseases, but its exact effects on organ dysfunction are largely unknown1. Hair follicles-mini-epithelial organs that grow hair-are miniaturized by ageing to cause hair loss through the depletion of hair follicle stem cells (HFSCs)2. Here we report that obesity-induced stress, such as that induced by a high-fat diet (HFD), targets HFSCs to accelerate hair thinning. Chronological gene expression analysis revealed that HFD feeding for four consecutive days in young mice directed activated HFSCs towards epidermal keratinization by generating excess reactive oxygen species, but did not reduce the pool of HFSCs. Integrative analysis using stem cell fate tracing, epigenetics and reverse genetics showed that further feeding with an HFD subsequently induced lipid droplets and NF-κB activation within HFSCs via autocrine and/or paracrine IL-1R signalling. These integrated factors converge on the marked inhibition of Sonic hedgehog (SHH) signal transduction in HFSCs, thereby further depleting lipid-laden HFSCs through their aberrant differentiation and inducing hair follicle miniaturization and eventual hair loss. Conversely, transgenic or pharmacological activation of SHH rescued HFD-induced hair loss. These data collectively demonstrate that stem cell inflammatory signals induced by obesity robustly represses organ regeneration signals to accelerate the miniaturization of mini-organs, and suggests the importance of daily prevention of organ dysfunction.


Assuntos
Alopecia/patologia , Alopecia/fisiopatologia , Folículo Piloso/patologia , Obesidade/fisiopatologia , Células-Tronco/patologia , Animais , Comunicação Autócrina , Contagem de Células , Diferenciação Celular , Linhagem da Célula , Senescência Celular , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Proteínas Hedgehog/metabolismo , Inflamação , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/patologia , Estresse Oxidativo , Comunicação Parácrina , Receptores de Interleucina-1/metabolismo
3.
Sci Rep ; 11(1): 11137, 2021 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-34045514

RESUMO

A growing body of evidence indicates that cellular metabolism is involved in immune cell functions, including cytokine production. Serine is a nutritionally non-essential amino acid that can be generated by de novo synthesis and conversion from glycine. Serine contributes to various cellular responses, but the role in inflammatory responses remains poorly understood. Here, we show that macrophages rely on extracellular serine to suppress aberrant cytokine production. Depleting serine from the culture media reduced the cellular serine content in macrophages markedly, suggesting that macrophages depend largely on extracellular serine rather than cellular synthesis. Under serine deprivation, macrophages stimulated with lipopolysaccharide showed aberrant cytokine expression patterns, including a marked reduction of anti-inflammatory interleukin-10 expression and sustained expression of interleukine-6. Transcriptomic and metabolomics analyses revealed that serine deprivation causes mitochondrial dysfunction: reduction in the pyruvate content, the NADH/NAD+ ratio, the oxygen consumption rate, and the mitochondrial production of reactive oxygen species (ROS). We also found the role of mitochondrial ROS in appropriate cytokine production. Thus, our results indicate that cytokine production in macrophages is tightly regulated by the nutritional microenvironment.

4.
Biomed Pharmacother ; 140: 111738, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34029949

RESUMO

BACKGROUND: Diabetes and obesity contribute to the pathogenesis of nonalcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC). However, how diabetes and obesity accelerate liver tumorigenesis remains to be fully understood. Moreover, to verify the therapeutic potential of anti-diabetic drugs, there exists a strong need for appropriate animal models that recapitulate human pathophysiology of NASH and HCC. METHODS: We established a novel murine model of NASH-associated liver tumors using genetically obese melanocortin 4 receptor-deficient mice fed on Western diet in combination with a chemical procarcinogen, and verified the validity of our model in evaluating drug efficacy. FINDINGS: Our model developed multiple liver tumors together with obesity, diabetes, and NASH within a relatively short period (approximately 3 months). In this model, sodium glucose cotransporter 2 inhibitor Tofogliflozin prevented the development of NASH-like liver phenotypes and the progression of liver tumors. Tofogliflozin attenuated p21 expression of hepatocytes in non-tumorous lesions in the liver. INTERPRETATION: Tofogliflozin treatment attenuates cellular senescence of hepatocytes under obese and diabetic conditions. This study provides a unique animal model of NASH-associated liver tumors, which is applicable for assessing drug efficacy to prevent or treat NASH-associated HCC.


Assuntos
Compostos Benzidrílicos/uso terapêutico , Glucosídeos/uso terapêutico , Neoplasias Hepáticas/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Inibidores do Transportador 2 de Sódio-Glicose/uso terapêutico , Animais , Compostos Benzidrílicos/farmacologia , Glicemia/análise , Senescência Celular/efeitos dos fármacos , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/etiologia , Diabetes Mellitus Experimental/patologia , Dieta Ocidental , Modelos Animais de Doenças , Progressão da Doença , Glucosídeos/farmacologia , Hepatócitos/efeitos dos fármacos , Insulina/sangue , Fígado/efeitos dos fármacos , Fígado/patologia , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/etiologia , Neoplasias Hepáticas/patologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Hepatopatia Gordurosa não Alcoólica/sangue , Hepatopatia Gordurosa não Alcoólica/complicações , Hepatopatia Gordurosa não Alcoólica/patologia , Obesidade/sangue , Obesidade/complicações , Obesidade/tratamento farmacológico , Obesidade/patologia , Receptor Tipo 4 de Melanocortina/genética , Inibidores do Transportador 2 de Sódio-Glicose/farmacologia
5.
Endocr J ; 68(7): 743-749, 2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-33967185

RESUMO

Nonalcoholic fatty liver disease (NAFLD) is a clinical spectrum that encompasses simple steatosis to nonalcoholic steatohepatitis (NASH), the latter of which is characterized by chronic inflammation and fibrosis. NASH is now becoming the leading cause of cirrhosis and hepatocellular carcinoma worldwide. The pathophysiology of NASH is multifactorial and, therefore, not yet completely understood, although it is pointed out that hepatocyte death and subsequent inflammation play a central roles in disease pathogenesis. Since stromal cells dramatically change their cellular components and activation status as liver fibrosis develops, it is important to reveal the subset responsible for the disease development in each etiology. Macrophages foam crown-like structures (CLS), in which CD11c-positive macrophages surround dead hepatocytes induced by lipotoxic injury in mouse and human NASH. Hepatic CLS-constituting macrophages exhibit gene expression profiles distinct from other scattered macrophages in the liver, suggesting NASH-specific macrophages represent a subset that drives metabolic stress-induced liver fibrosis. Moreover, cancer-associated pathways are upregulated in activated fibroblasts from the liver of a mouse NASH model, suggesting that fibroblasts provide the microenvironment that promotes tumor progression. A better understanding of the upstream signals and regulatory mechanisms that drive the generation of NASH-specific macrophage and fibroblast subsets is crucial for the development of novel diagnostic and therapeutic strategies.

6.
iScience ; 24(2): 102032, 2021 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-33521599

RESUMO

Although recent evidence suggests the involvement of iron accumulation in the pathogenesis of nonalcoholic steatohepatitis (NASH), the underlying mechanisms remain poorly understood. Previously, we reported a unique histological structure termed "crown-like structure (CLS)," where liver-resident macrophages (Kupffer cells) surround dead hepatocytes, scavenge their debris, and induce inflammation and fibrosis in NASH. In this study, using magnetic column separation, we show that iron-rich Kupffer cells exhibit proinflammatory and profibrotic phenotypic changes during the development of NASH, at least partly, through activation of MiT/TFE transcription factors. Activation of MiT/TFE transcription factors is observed in Kupffer cells forming CLSs in murine and human NASH. Iron chelation effectively attenuates liver fibrosis in a murine NASH model. This study provides insight into the pathophysiologic role of iron in NASH. Our data also shed light on a unique macrophage subset rich in iron that contributes to CLS formation and serves as a driver of liver fibrosis.

7.
Sci Adv ; 6(51)2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33355142

RESUMO

Rs671 in the aldehyde dehydrogenase 2 gene (ALDH2) is the cause of Asian alcohol flushing response after drinking. ALDH2 detoxifies endogenous aldehydes, which are the major source of DNA damage repaired by the Fanconi anemia pathway. Here, we show that the rs671 defective allele in combination with mutations in the alcohol dehydrogenase 5 gene, which encodes formaldehyde dehydrogenase (ADH5FDH ), causes a previously unidentified disorder, AMeD (aplastic anemia, mental retardation, and dwarfism) syndrome. Cellular studies revealed that a decrease in the formaldehyde tolerance underlies a loss of differentiation and proliferation capacity of hematopoietic stem cells. Moreover, Adh5-/-Aldh2 E506K/E506K double-deficient mice recapitulated key clinical features of AMeDS, showing short life span, dwarfism, and hematopoietic failure. Collectively, our results suggest that the combined deficiency of formaldehyde clearance mechanisms leads to the complex clinical features due to overload of formaldehyde-induced DNA damage, thereby saturation of DNA repair processes.

8.
Nagoya J Med Sci ; 82(3): 391-397, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33132423

RESUMO

The pathological spectrum of nonalcoholic fatty liver disease includes simple steatosis and nonalcoholic steatohepatitis (NASH), the latter of which is the leading cause of cirrhosis and hepatocellular carcinoma. The available evidence shows that parenchymal cell injury and death trigger inflammation and tissue fibrosis. During the development of liver fibrosis, stromal cells dramatically changes in their cellular component and activation status responding to hepatocyte injury due to various etiologies. It is important to understand how cell death induces chronic inflammation and fibrosis, and the disease-specific macrophages and fibroblasts responsible for NASH development under metabolic stress. This review discusses recent progress in the understanding the pathogenesis of NASH, focusing on disease-specific macrophages and fibroblasts.

9.
Biochem Biophys Res Commun ; 530(4): 665-672, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32768187

RESUMO

The role of sphingosine 1-phosphate (S1P) and its sphingosine-1-phosphate receptors (S1PRs) in non-alcoholic steatohepatitis (NASH) is unclear. We aimed to analyze the role of S1P/S1PRs in a Melanocortin-4 receptor (Mc4r)-deficient NASH murine model using FTY720, the functional antagonist of S1PR1, S1PR3, S1PR4, and S1PR5, and JTE-013, the antagonist of S1PR2. We observed that, compared to that in the control, the mRNA of S1pr1 tended to decrease, whereas those of S1pr2 and S1pr3 significantly increased in Mc4r-knockout (KO) mice subjected to a Western diet (WD). While the fat area did not differ, fibrosis progression differed significantly between control mice and mice in which liver S1PRs were blocked. Lipidomic and metabolomic analysis of liver tissues showed that JTE-013-administered mice showed elevation of S-adenosyl-l-methionine level, which can induce aberrant methylation due to reduction in glycine N-methyltransferase (GNMT) and elevation in diacylglycerol (DG) and triacylglycerol (TG) levels, leading to increased susceptibility to hepatocellular carcinoma (HCC). These phenotypes are similar to those of Gnmt-KO mice, suggesting that blocking the S1P/S1PR2 axis triggers aberrant methylation, which may increase DG and TG, and hepatocarcinogenesis. Our observations that the S1P/S1PR2 axis averts HCC occurrence may assist in HCC prevention in NASH.


Assuntos
Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Hepatopatia Gordurosa não Alcoólica/patologia , Receptores de Esfingosina-1-Fosfato/metabolismo , Animais , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Modelos Animais de Doenças , Progressão da Doença , Regulação da Expressão Gênica , Glicina N-Metiltransferase/genética , Glicina N-Metiltransferase/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/metabolismo , Receptor Tipo 4 de Melanocortina/genética , Receptor Tipo 4 de Melanocortina/metabolismo , Receptores de Esfingosina-1-Fosfato/antagonistas & inibidores , Receptores de Esfingosina-1-Fosfato/genética
10.
J Exp Med ; 217(11)2020 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-32797195

RESUMO

Accumulating evidence indicates that cell death triggers sterile inflammation and that impaired clearance of dead cells causes nonresolving inflammation; however, the underlying mechanisms are still unclear. Here, we show that macrophage-inducible C-type lectin (Mincle) senses renal tubular cell death to induce sustained inflammation after acute kidney injury in mice. Mincle-deficient mice were protected against tissue damage and subsequent atrophy of the kidney after ischemia-reperfusion injury. Using lipophilic extract from the injured kidney, we identified ß-glucosylceramide as an endogenous Mincle ligand. Notably, free cholesterol markedly enhanced the agonistic effect of ß-glucosylceramide on Mincle. Moreover, ß-glucosylceramide and free cholesterol accumulated in dead renal tubules in proximity to Mincle-expressing macrophages, where Mincle was supposed to inhibit clearance of dead cells and increase proinflammatory cytokine production. This study demonstrates that ß-glucosylceramide in combination with free cholesterol acts on Mincle as an endogenous ligand to induce cell death-triggered, sustained inflammation after acute kidney injury.


Assuntos
Injúria Renal Aguda/metabolismo , Morte Celular/genética , Lectinas Tipo C/metabolismo , Proteínas de Membrana/metabolismo , Injúria Renal Aguda/imunologia , Animais , Citocinas/metabolismo , Modelos Animais de Doenças , Feminino , Glucosilceramidase/metabolismo , Proteínas de Fluorescência Verde/genética , Inflamação/metabolismo , Lectinas Tipo C/deficiência , Lectinas Tipo C/genética , Ligantes , Macrófagos/imunologia , Macrófagos/metabolismo , Masculino , Proteínas de Membrana/deficiência , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transdução de Sinais/genética , Transdução de Sinais/imunologia
11.
Endocrinology ; 161(9)2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32603429

RESUMO

The hypothalamus plays a critical role in controlling energy balance. High-fat diet (HFD) feeding increases the gene expression of proinflammatory mediators and decreases insulin actions in the hypothalamus. Here, we show that a gut-derived hormone, glucose-dependent insulinotropic polypeptide (GIP), whose levels are elevated during diet-induced obesity, promotes and mediates hypothalamic inflammation and insulin resistance during HFD-induced obesity. Unbiased ribonucleic acid sequencing of GIP-stimulated hypothalami revealed that hypothalamic pathways most affected by intracerebroventricular (ICV) GIP stimulation were related to inflammatory-related responses. Subsequent analysis demonstrated that GIP administered either peripherally or centrally, increased proinflammatory-related factors such as Il-6 and Socs3 in the hypothalamus, but not in the cortex of C57BL/6J male mice. Consistently, hypothalamic activation of IκB kinase-ß inflammatory signaling was induced by ICV GIP. Further, hypothalamic levels of proinflammatory cytokines and Socs3 were significantly reduced by an antagonistic GIP receptor (GIPR) antibody and by GIPR deficiency. Additionally, centrally administered GIP reduced anorectic actions of insulin in the brain and diminished insulin-induced phosphorylation of Protein kinase B and Glycogen synthase kinase 3ß in the hypothalamus. Collectively, these findings reveal a previously unrecognized role for brain GIP signaling in diet-induced inflammation and insulin resistance in the hypothalamus.


Assuntos
Encefalite/induzido quimicamente , Polipeptídeo Inibidor Gástrico/farmacologia , Hipotálamo/efeitos dos fármacos , Inflamação/induzido quimicamente , Resistência à Insulina , Receptores dos Hormônios Gastrointestinais/fisiologia , Animais , Dieta Hiperlipídica , Encefalite/genética , Polipeptídeo Inibidor Gástrico/administração & dosagem , Polipeptídeo Inibidor Gástrico/fisiologia , Hipotálamo/imunologia , Hipotálamo/patologia , Inflamação/genética , Infusões Intraventriculares , Resistência à Insulina/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Obesos , Receptores dos Hormônios Gastrointestinais/genética , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genética
12.
Commun Biol ; 3(1): 313, 2020 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-32555343

RESUMO

Accumulating evidence demonstrates that not only sustained elevation of blood glucose levels but also the glucose fluctuation represents key determinants for diabetic complications and mortality. Current closed-loop insulin therapy option is limited to the use of electronics-based systems, although it poses some technical issues with high cost. Here we demonstrate an electronics-free, synthetic boronate gel-based insulin-diffusion-control device technology that can cope with glucose fluctuations and potentially address the electronics-derived issues. The gel was combined with hemodialysis hollow fibers and scaled suitable for rats, serving as a subcutaneously implantable, insulin-diffusion-active site in a manner dependent on the subcutaneous glucose. Continuous glucose monitoring tests revealed that our device not only normalizes average glucose level of rats, but also markedly ameliorates the fluctuations over timescale of a day without inducing hypoglycemia. With inherent stability, diffusion-dependent scalability, and week-long & acute glucose-responsiveness, our technology may offer a low-cost alternative to current electronics-based approaches.


Assuntos
Glicemia/metabolismo , Géis/química , Sistemas de Infusão de Insulina , Insulina/administração & dosagem , Animais , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/tratamento farmacológico , Liberação Controlada de Fármacos , Eletrônica , Desenho de Equipamento , Insulina/farmacocinética , Insulina Regular Humana/administração & dosagem , Insulina Regular Humana/genética , Rins Artificiais , Masculino , Modelos Teóricos , Ratos Sprague-Dawley , Temperatura
13.
Regen Ther ; 14: 252-261, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32455155

RESUMO

Introduction: Currently, there are no approved drugs for treating non-alcoholic steatohepatitis (NASH); however, mesenchymal stem cells (MSCs) and their small extracellular vesicles (sEVs), which possess immunomodulatory activities, are potential candidates. This study aimed to develop a mouse model of NASH with rapid accumulation of fibrosis using the pre-established melanocortin type-4 receptor knockout (Mc4r-KO) NASH mouse model and lipopolysaccharide (LPS), and to evaluate the therapeutic effect of MSCs and their sEVs. Methods: Mc4r-KO mice (8 weeks old, male) were fed a western diet (WD) for 8 weeks. Next, the mice were intraperitoneally injected with lipopolysaccharide (LPS) twice a week for 4 weeks while continuing the WD. To confirm the therapeutic effect of MSCs and sEVs, human adipose tissue-derived MSCs or their sEVs were administered 12 weeks after initiation of the WD, and serum testing, quantitative analysis of fibrosis, and quantitative reverse transcription-polymerase chain reaction qRT-PCR were performed. Results: By providing a WD combined with LPS treatment, we successfully developed a NASH model with rapid accumulation of fibrosis. Both human MSCs and their sEVs decreased serum alanine transaminase levels and inflammatory markers based on qRT-PCR. Histological analysis showed that MSC or sEV treatment did not affect fat accumulation. However, an improvement in fibrosis in the groups treated with MSCs and their sEVs was observed. Furthermore, after administering MSCs and sEVs, there was a significant increase in anti-inflammatory macrophages in the liver. Conclusion: We successfully developed a NASH model with rapid accumulation of fibrosis and confirmed the anti-inflammatory and anti-fibrotic effects of MSCs and their sEVs, which may be options for future therapy.

14.
Cell ; 180(6): 1228-1244.e24, 2020 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-32142649

RESUMO

Transcription-coupled nucleotide excision repair (TC-NER) is initiated by the stalling of elongating RNA polymerase II (RNAPIIo) at DNA lesions. The ubiquitination of RNAPIIo in response to DNA damage is an evolutionarily conserved event, but its function in mammals is unknown. Here, we identified a single DNA damage-induced ubiquitination site in RNAPII at RPB1-K1268, which regulates transcription recovery and DNA damage resistance. Mechanistically, RPB1-K1268 ubiquitination stimulates the association of the core-TFIIH complex with stalled RNAPIIo through a transfer mechanism that also involves UVSSA-K414 ubiquitination. We developed a strand-specific ChIP-seq method, which revealed RPB1-K1268 ubiquitination is important for repair and the resolution of transcriptional bottlenecks at DNA lesions. Finally, RPB1-K1268R knockin mice displayed a short life-span, premature aging, and neurodegeneration. Our results reveal RNAPII ubiquitination provides a two-tier protection mechanism by activating TC-NER and, in parallel, the processing of DNA damage-stalled RNAPIIo, which together prevent prolonged transcription arrest and protect against neurodegeneration.


Assuntos
Reparo do DNA/fisiologia , RNA Polimerase II/metabolismo , Animais , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , DNA/metabolismo , Dano ao DNA/fisiologia , DNA Helicases/metabolismo , Enzimas Reparadoras do DNA/genética , Enzimas Reparadoras do DNA/metabolismo , Feminino , Células HCT116 , Células HEK293 , Células HeLa , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , RNA Polimerase II/genética , Ubiquitinação
15.
Sci Rep ; 10(1): 983, 2020 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-31969650

RESUMO

Nonalcoholic steatohepatitis (NASH) is a hepatic phenotype of the metabolic syndrome, and increases the risk of cirrhosis and hepatocellular carcinoma (HCC). Although increasing evidence points to the therapeutic implications of certain types of anti-diabetic agents in NASH, it remains to be elucidated whether their effects on NASH are independent of their effects on diabetes. Genetically obese melanocortin 4 receptor-deficient (MC4R-KO) mice fed Western diet are a murine model that sequentially develops hepatic steatosis, NASH, and HCC in the presence of obesity and insulin resistance. In this study, we investigated the effect of the dipeptidyl peptidase-4 (DPP-4) inhibitor anagliptin on NASH and HCC development in MC4R-KO mice. Anagliptin treatment effectively prevented inflammation, fibrosis, and carcinogenesis in the liver of MC4R-KO mice. Interestingly, anagliptin only marginally affected body weight, systemic glucose and lipid metabolism, and hepatic steatosis. Histological data and gene expression analysis suggest that anagliptin treatment targets macrophage activation in the liver during the progression from simple steatosis to NASH. As a molecular mechanism underlying anagliptin action, we showed that glucagon-like peptide-1 suppressed proinflammatory and profibrotic phenotypes of macrophages in vitro. This study highlights the glucose metabolism-independent effects of anagliptin on NASH and HCC development.


Assuntos
Carcinoma Hepatocelular/prevenção & controle , Inibidores da Dipeptidil Peptidase IV/farmacologia , Cirrose Hepática/prevenção & controle , Neoplasias Hepáticas/prevenção & controle , Hepatopatia Gordurosa não Alcoólica/prevenção & controle , Substâncias Protetoras/farmacologia , Pirimidinas/farmacologia , Animais , Carcinoma Hepatocelular/patologia , Inibidores da Dipeptidil Peptidase IV/uso terapêutico , Modelos Animais de Doenças , Fígado/efeitos dos fármacos , Fígado/patologia , Cirrose Hepática/patologia , Neoplasias Hepáticas/patologia , Masculino , Camundongos , Hepatopatia Gordurosa não Alcoólica/patologia , Substâncias Protetoras/uso terapêutico , Pirimidinas/uso terapêutico
16.
Sci Rep ; 9(1): 19601, 2019 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-31862949

RESUMO

Non-alcoholic steatohepatitis (NASH), characterized by chronic inflammation and fibrosis, is predicted to be the leading cause of cirrhosis and hepatocellular carcinoma (HCC) in the next decade. Although recent evidence suggests the importance of fibrosis as the strongest determinant of HCC development, the molecular mechanisms underlying NASH-induced carcinogenesis still remain unclear. Here we performed RNA sequencing analysis to compare gene expression profiles of activated fibroblasts prepared from two distinct liver fibrosis models: carbon tetrachloride-induced fibrosis as a model without obesity and HCC and genetically obese melanocortin 4 receptor-deficient (MC4R-KO) mice fed Western diet, which develop steatosis, NASH, and eventually HCC. Our data showed that activated fibroblasts exhibited distinct gene expression patterns in each etiology, and that the 'pathways in cancer' were selectively upregulated in the activated fibroblasts from MC4R-KO mice. The most upregulated gene in these pathways was fibroblast growth factor 9 (FGF9), which was induced by metabolic stress such as palmitate. FGF9 exerted anti-apoptotic and pro-migratory effects in fibroblasts and hepatoma cells in vitro and accelerated tumor growth in a subcutaneous xenograft model. This study reveals upregulation of cancer-associated gene expression in activated fibroblasts in NASH, which would contribute to the progression from NASH to HCC.


Assuntos
Fibroblastos/metabolismo , Regulação Neoplásica da Expressão Gênica , Neoplasias/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Regulação para Cima , Animais , Apoptose , Carcinoma Hepatocelular/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Progressão da Doença , Fator 9 de Crescimento de Fibroblastos/genética , Perfilação da Expressão Gênica , Humanos , Fígado/metabolismo , Cirrose Hepática/metabolismo , Neoplasias Hepáticas/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transplante de Neoplasias
17.
Magn Reson Imaging ; 57: 210-217, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30465867

RESUMO

INTRODUCTION: Melanocortin 4 receptor-deficient (MC4R-KO) mice fed a high-fat diet (HFD) develop liver pathology similar to human nonalcoholic steatohepatitis (NASH). However, although liver histology and blood biochemistry have been reported, hepatic function has not been evaluated. In the present study, we evaluated hepatic function in MC4R-KO mice fed an HFD using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) with gadolinium­ethoxybenzyl­diethylenetriamine pentaacetic acid (Gd-EOB-DTPA). MATERIALS AND METHODS: Wild type (WT) mice and MC4R-KO mice were fed a standard diet (SD) or an HFD for 20 weeks. The hepatic signal intensity was obtained from DCE-MRI images, and relative enhancement (RE), the time to maximum RE (Tmax), and the half-life of RE elimination (T1/2) were calculated. Histopathological analysis was then performed. RESULTS: Histological analysis with nonalcoholic fatty liver disease activity score (NAS) revealed that MC4R-KO mice fed an HFD achieved the NAS of 5. There was moderate fibrosis in MC4R-KO mice fed an HFD. DCE-MRI with Gd-EOB-DTPA showed that Tmax and T1/2 were significantly longer in MC4R-KO mice fed an HFD compared with wild type (WT) mice (Tmax, WT, 3.9 ±â€¯0.4 min; MC4R-KO, 7.4 ±â€¯1.5 min; T1/2, WT, 23.7 ±â€¯1.9 min; MC4R-KO, 62.5 ±â€¯18.5 min). Tmax and T1/2 were significantly correlated with histopathologic score (steatosis vs. Tmax, rho = 0.48, P = 0.04; steatosis vs. T1/2, rho = 0.50, P = 0.03; inflammation vs. Tmax, rho = 0.55, P = 0.02; inflammation vs. T1/2, rho = 0.61, P < 0.01; ballooning vs. T1/2, rho = 0.51, P = 0.03;fibrosis vs Tmax, rho = 0.72, P < 0.01; fibrosis vs T1/2, rho = 0.75, P < 0.01). CONCLUSIONS: MC4R-KO mice fed an HFD developed obesity and NASH. The liver kinetics of Gd-EOB-DTPA were significantly different in MC4R-KO mice fed an HFD from WT mice, and correlated with the histopathologic score. These results suggest that MC4R-KO mice fed an HFD mimic the hepatic pathology and liver function of human NASH, and therefore might be useful for the study of hepatic dysfunction during the fibrotic stage of NASH.


Assuntos
Meios de Contraste , Aumento da Imagem/métodos , Fígado/fisiopatologia , Imageamento por Ressonância Magnética/métodos , Hepatopatia Gordurosa não Alcoólica/diagnóstico por imagem , Hepatopatia Gordurosa não Alcoólica/fisiopatologia , Animais , Modelos Animais de Doenças , Gadolínio DTPA , Fígado/diagnóstico por imagem , Fígado/patologia , Camundongos , Hepatopatia Gordurosa não Alcoólica/patologia , Receptor Tipo 4 de Melanocortina/deficiência
18.
ACS Biomater Sci Eng ; 5(11): 5781-5789, 2019 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-33405670

RESUMO

Microneedle (MN) technology, which can transdermally deliver insulin in a noninvasive manner, offers a promising way to replace subcutaneous self-injection for diabetes management. Hydrogel is an attractive candidate for MN fabrication because of its biocompatibility, controllable degradability, and possibility to achieve sustained as well as stimuli-responsive drug delivery. Herein, we report a smart MN composed of a semi-interpenetrating network (semi-IPN) hydrogel prepared by biocompatible silk fibroin (SF) and phenylboronic acid/acrylamide for glucose-responsive insulin delivery. Six fabrication methods were investigated to maintain the glucose sensitivity of the hydrogel while avoiding deformation during fabrication. The optimized method was to fabricate smart MNs using a two-layer strategy, with a needle region formed by the SF combined semi-IPN hydrogel and the base layer fabricated by SF. The hybrid MN autonomously released insulin well-correspondent to the glucose change pattern via the regulation of the skin layer formed on the surface. Furthermore, this hybrid MN retained its original needle shape after 1 week in aqueous system, thus eliminating the safety concerns associated with dissolving MNs and suggesting the possibility for sustained delivery. This nondegradable smart MN is promising to provide on-demand insulin in a long-acting, painless, and convenient way.

19.
Sci Rep ; 8(1): 8157, 2018 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-29802399

RESUMO

Accumulating evidence has suggested that farnesoid X receptor (FXR) agonists, such as obeticholic acid (OCA) are therapeutically useful for non-alcoholic steatohepatitis (NASH). However, it is still unclear how FXR agonists protect against NASH and which cell type is the main target of FXR agonists. In this study, we examined the effects of OCA on the development of NASH using melanocortin 4 receptor-deficient (MC4R-KO) mice that progressively developed hepatic steatosis and NASH on Western diet (WD). Treatment with OCA effectively prevented chronic inflammation and liver fibrosis in WD-fed MC4R-KO mice with only marginal effect on body weight and hepatic steatosis. Hepatic crown-like structure (hCLS) is a unique histological structure characteristic of NASH, which triggers hepatocyte death-induced interstitial fibrosis. Intriguingly, treatment with OCA markedly reduced hCLS formation even after MC4R-KO mice developed NASH, thereby inhibiting the progression of liver fibrosis. As its mechanism of action, OCA suppressed metabolic stress-induced p53 activation and cell death in hepatocytes. Our findings in this study highlight the role of FXR in hepatocytes in the pathogenesis of NASH. Collectively, this study demonstrates the anti-fibrotic effect of OCA in a murine model of NASH with obesity and insulin resistance, which suggests the clinical implication for human NASH.


Assuntos
Morte Celular/efeitos dos fármacos , Ácido Quenodesoxicólico/análogos & derivados , Citoproteção/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Hepatócitos/patologia , Cirrose Hepática/prevenção & controle , Hepatopatia Gordurosa não Alcoólica/complicações , Animais , Peso Corporal/efeitos dos fármacos , Ácido Quenodesoxicólico/farmacologia , Modelos Animais de Doenças , Progressão da Doença , Técnicas de Inativação de Genes , Hepatócitos/metabolismo , Resistência à Insulina , Cirrose Hepática/complicações , Cirrose Hepática/patologia , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/complicações , Receptor Tipo 4 de Melanocortina/deficiência , Receptor Tipo 4 de Melanocortina/genética , Proteína Supressora de Tumor p53/metabolismo
20.
Sci Rep ; 8(1): 2362, 2018 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-29402900

RESUMO

Sodium glucose cotransporter 2 (SGLT2) inhibitors, an antidiabetic drug, promotes urinary excretion of glucose by blocking its reabsorption in the renal proximal tubules. It is unclear whether SGLT2 inhibition could attenuate nonalcoholic steatohepatitis (NASH) and NASH-associated hepatocellular carcinoma. We examined the preventive effects of an SGLT2 inhibitor canagliflozin (CANA) in Western diet (WD)-fed melanocortin 4 receptor-deficient (MC4R-KO) mice, a mouse model of human NASH. An eight-week CANA treatment attenuated hepatic steatosis in WD-fed MC4R-KO mice, with increased epididymal fat mass without inflammatory changes. CANA treatment for 20 weeks inhibited the development of hepatic fibrosis in WD-fed MC4R-KO mice. After one year of CANA treatment, the number of liver tumors was significantly reduced in WD-fed MC4R-KO mice. In adipose tissue, CANA suppressed the ratio of oxidative to reduced forms of glutathiones (GSSG/GSH) in WD-fed MC4R-KO mice. Treatment with GSH significantly attenuated the H2O2-induced upregulation of genes related to NADPH oxidase in 3T3-L1 adipocytes, and that of Il6, Tgfb, and Pdgfb in RAW264.7 cells. This study provides evidence that SGLT2 inhibitors represent the unique class of drugs that can attenuate or delay the onset of NASH and eventually hepatocellular carcinoma, at least partly, through "healthy adipose expansion".


Assuntos
Canagliflozina/administração & dosagem , Carcinoma Hepatocelular/prevenção & controle , Neoplasias Hepáticas/prevenção & controle , Hepatopatia Gordurosa não Alcoólica/complicações , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Inibidores do Transportador 2 de Sódio-Glicose/administração & dosagem , Animais , Modelos Animais de Doenças , Fígado/patologia , Camundongos , Camundongos Knockout , Receptor Tipo 4 de Melanocortina/deficiência , Resultado do Tratamento
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