RESUMO
Cancer chemotherapy and radiotherapy may result in mucositis characterized by stem cell damage and inflammation in the gastrointestinal tract. The molecular mechanisms underlying this pathology remain unknown. Based on the assumption that mitochondrial CPG-DNA (mtDNA) released and sensed by TLR9 could underlie mucositis pathology, we analyzed the mtDNA levels in sera as well as inflammatory and disease parameters in the small intestine from wild-type (WT) and TLR9-deficient mice (TLR9-/-) in an experimental model of intestinal mucositis induced by irinotecan. Additionally, we verified the ability of WT and TLR9-/- macrophages to respond to CpG-DNA in vitro. WT mice injected with irinotecan presented a progressive increase in mtDNA in the serum along with increased hematocrit, shortening of small intestine length, reduction of intestinal villus:crypt ratio and increased influx of neutrophils, which were followed by higher expression of Nlrp3 and Casp1 mRNA and increased IL-1ß levels in the ileum when compared to vehicle-injected mice. TLR9-deficient mice were protected in all these parameters when compared to WT mice. Furthermore, TLR9 was required for the production of IL-1ß and NO after macrophage stimulation with CpG-DNA. Overall, our findings show that the amount of circulating free CpG-DNA is increased upon chemotherapy and that TLR9 activation is important for NLRP3 inflammasome transcription and further IL-1ß release, playing a central role in the development of irinotecan-induced intestinal mucositis. We suggest that TLR9 antagonism may be a new therapeutic strategy for limiting irinotecan-induced intestinal inflammation.
Assuntos
Mucosite , Animais , DNA Mitocondrial/genética , Inflamação/metabolismo , Irinotecano/toxicidade , Ligantes , Camundongos , Camundongos Knockout , Mucosite/induzido quimicamente , Mucosite/tratamento farmacológico , Mucosite/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR , Receptor Toll-Like 9/genética , Receptor Toll-Like 9/metabolismoRESUMO
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/fisiologiaRESUMO
Mucositis is a major clinical complication associated with cancer treatment and may limit the benefit of chemotherapy. Leukocytes and inflammatory mediators have been extensively associated with mucositis severity. However, the role of eosinophils in the pathophysiology of chemotherapy-induced mucositis remains to be elucidated. Here, using GATA-1-deficient mice, we investigated the role of eosinophils in intestinal mucositis. There was marked accumulation of eosinophils in mice given irinotecan and eosinophil ablation inhibited intestinal mucositis. Treatment with Evasin-4, a chemokine receptor antagonist, reduced the recruitment of eosinophils and decreased irinotecan-induced mucositis. Importantly, Evasin-4 did not interfere negatively with the antitumour effects of irinotecan. Evasin-4 was of benefit for mice given high doses of irinotecan once Evasin-4-treated mice presented delayed mortality. Altogether, our findings suggest that Evasin-4 may have significant mucosal-protective effects in the context of antineoplastic chemotherapy and may, therefore, be useful in combination with anticancer treatment in cancer patients.
Assuntos
Antineoplásicos , Mucosite , Animais , Antineoplásicos/uso terapêutico , Camptotecina/efeitos adversos , Eosinófilos/patologia , Humanos , Mucosa Intestinal/patologia , Irinotecano/efeitos adversos , Camundongos , Mucosite/induzido quimicamente , Mucosite/tratamento farmacológico , Mucosite/patologiaRESUMO
Although dysbiosis in the gut microbiota is known to be involved in several inflammatory diseases, whether any specific bacterial taxa control host response to inflammatory stimuli is still elusive. Here, we hypothesized that dysbiotic indigenous taxa could be involved in modulating host response to inflammatory triggers. To test this hypothesis, we conducted experiments in germ-free (GF) mice and in mice colonized with dysbiotic taxa identified in conventional (CV) mice subjected to chemotherapy-induced mucositis. First, we report that the absence of microbiota decreased inflammation and damage in the small intestine after administration of the chemotherapeutic agent 5-fluorouracil (5-FU). Also, 5-FU induced a shift in CV microbiota resulting in higher amounts of Enterobacteriaceae, including E. coli, in feces and small intestine and tissue damage. Prevention of Enterobacteriaceae outgrowth by treating mice with ciprofloxacin resulted in diminished 5-FU-induced tissue damage, indicating that this bacterial group is necessary for 5-FU-induced inflammatory response. In addition, monocolonization of germ-free (GF) mice with E. coli led to reversal of the protective phenotype during 5-FU chemotherapy. E. coli monocolonization decreased the basal plasma corticosterone levels and blockade of glucocorticoid receptor in GF mice restored inflammation upon 5-FU treatment. In contrast, treatment of CV mice with ciprofloxacin, that presented reduction of Enterobacteriaceae and E. coli content, induced an increase in corticosterone levels. Altogether, these findings demonstrate that Enterobacteriaceae outgrowth during dysbiosis impacts inflammation and tissue injury in the small intestine. Importantly, indigenous Enterobacteriaceae modulates host production of the anti-inflammatory steroid corticosterone and, consequently, controls inflammatory responsiveness in mice.
Assuntos
Corticosterona/metabolismo , Disbiose/microbiologia , Enterobacteriaceae/crescimento & desenvolvimento , Animais , Antineoplásicos/efeitos adversos , Bactérias/classificação , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Bactérias/isolamento & purificação , Corticosterona/imunologia , Disbiose/etiologia , Disbiose/imunologia , Disbiose/metabolismo , Enterobacteriaceae/genética , Fluoruracila/efeitos adversos , Microbioma Gastrointestinal/efeitos dos fármacos , Humanos , Intestino Delgado/imunologia , Intestino Delgado/metabolismo , Intestino Delgado/microbiologia , Masculino , CamundongosRESUMO
INTRODUCTION: Obesity is usually triggered by a nutrient overload that favors adipocyte hypertrophy and increases the number of pro-inflammatory cells and mediators into adipose tissue. These mediators may be regulated by suppressors of cytokine signaling (SOCS), such as SOCS2, which is involved in the regulation of the inflammatory response of many diseases, but its role in obesity is not yet known. We aimed to investigate the role of SOCS2 in metabolic and inflammatory dysfunction induced by a high-refined carbohydrate-containing diet (HC). MATERIAL AND METHODS: Male C57BL/6 wild type (WT) and SOCS2 deficient (SOCS2-/-) mice were fed chow or an HC diet for 8 weeks. RESULTS: In general, SOCS2 deficient mice, independent of the diet, showed higher adipose tissue mass compared with their WT counterparts that were associated with decreased lipogenesis rate in adipose tissue, lipolysis in adipocyte culture and energy expenditure. An anti-inflammatory profile was observed in adipose tissue of SOCS2-/- by reduced secretion of cytokines, such as TNF and IL-6, and increased M2-like macrophages and regulatory T cells compared with WT mice. Also, SOCS2 deficiency reduced the differentiation/expansion of pro-inflammatory cells in the spleen but increased Th2 and Treg cells compared with their WT counterparts. CONCLUSION: The SOCS2 protein is an important modulator of obesity that regulates the metabolic pathways related to adipocyte size. Additionally, SOCS2 is an inflammatory regulator that appears to be essential for controlling the release of cytokines and the differentiation/recruitment of cells into adipose tissue during the development of obesity.
Assuntos
Tecido Adiposo/metabolismo , Inflamação , Obesidade/metabolismo , Proteínas Supressoras da Sinalização de Citocina/metabolismo , Animais , Anti-Inflamatórios/farmacologia , Glicemia/metabolismo , Citocinas/metabolismo , Teste de Tolerância a Glucose , Insulina/metabolismo , Resistência à Insulina , Metabolismo dos Lipídeos , Lipogênese , Lipólise , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Consumo de Oxigênio , Proteínas Supressoras da Sinalização de Citocina/genética , Linfócitos T Reguladores/citologia , Células Th2/citologiaRESUMO
OBJECTIVES: Tumor necrosis factor (TNF) is a well-known cytokine that triggers insulin resistance during obesity development. On the other hand, it is also known that TNF induces a fat mass loss during acute diseases. However, whether TNF has a protective and physiological role to control adipose tissue expansion during obesity still needs to be verified. The aim of this study was to evaluate whether the ablation of TNF receptor 1 (TNFR1) alters fat mass and insulin resistance induced by a highly refined carbohydrate-containing (HC) diet. METHODS: Male C57 BL/6 wild-type (WT) mice and TNFR1 knockout (TNFR1-/-) mice were fed with chow or with the HC diet for 16 wk. RESULTS: TNFR1-/- mice gained more body weight than the WT groups independent of the diet composition. TNFR1-/- mice fed with the chow diet showed higher adiposity, accompanied by higher serum leptin levels. However, these mice showed lower non-esterified fatty acid levels. Furthermore, TNFR1-/- mice had suppressed TNF, interleukin (IL)-6, and IL-10 levels in adipose tissue compared with WT mice. TNFR1-/- mice fed with the HC diet were protected from increased adiposity and glucose intolerance induced by the HC diet and exhibited lower serum resistin levels. CONCLUSIONS: TNF signaling appears to have a paradoxical role on metabolism. Ablation of TNFR1 leads to a reduction of inflammatory cytokines in adipose tissue that is accompanied by higher adiposity in mice fed with chow diet. However, when these mice are given the HC diet, the loss of TNFR1 improves insulin sensitivity and protects mice against additional fat mass.
Assuntos
Tecido Adiposo/metabolismo , Dieta/efeitos adversos , Obesidade/metabolismo , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Animais , Carboidratos da Dieta/metabolismo , Modelos Animais de Doenças , Intolerância à Glucose/etiologia , Intolerância à Glucose/metabolismo , Resistência à Insulina/fisiologia , Leptina/sangue , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Obesidade/etiologia , Resistina/sangueRESUMO
OBJECTIVES: Studies suggest that sodium butyrate reduces obesity-associated inflammation and insulin resistance in in vitro and in vivo models. Apo E-/- mice have high basal oxidative stress and naturally develop dyslipidemia and atherosclerosis. Because these disorders are present in obesity, the aim of this study was to determine whether Apo E-/- mice could be a more realistic model for studying obesity and insulin resistance. METHODS: We evaluated the action of orally administered sodium butyrate on adipose tissue expansion and insulin resistance using diet-induced obese Apo E-/- mice. RESULTS: Findings from the present study demonstrated that obese mice fed a sodium butyrate-supplemented diet presented a modest reduction of weight gain associated with reduction of adipocyte expansion, induction of adipogenesis and angiogenesis, and adiponectin production. Sodium butyrate also improved insulin sensitivity, by increasing insulin receptor expression associated with activation of Akt signaling pathway. These results were associated with increased peroxisome proliferator-activated receptor-γ expression and nuclear factor-κB downregulation. CONCLUSION: These results suggested that oral supplementation of butyrate could be useful as an adjuvant in the treatment of obesity, metabolic syndrome, and insulin resistance.
Assuntos
Adipócitos/efeitos dos fármacos , Adipogenia/efeitos dos fármacos , Fármacos Antiobesidade/farmacologia , Ácido Butírico/farmacologia , Obesidade/terapia , Animais , Suplementos Nutricionais , Camundongos , Camundongos Knockout para ApoE , Camundongos Obesos , Obesidade/metabolismo , PPAR gama/metabolismo , Receptor de Insulina/metabolismo , Transdução de Sinais/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacosRESUMO
BACKGROUND: Mucositis is one of the most relevant gastrointestinal inflammatory conditions in humans, generated by the use of chemotherapy drugs, such as 5-fluoracil (5-FU). 5-FU-induced mucositis affects 80% of patients undergoing oncological treatment causing mucosal gut dysfunctions and great discomfort. As current therapy drugs presents limitations in alleviating mucositis symptoms, alternative strategies are being pursued. Recent studies have shown that the antimicrobial pancreatitis-associated protein (PAP) has a protective role in intestinal inflammatory processes. Indeed, it was demonstrated that a recombinant strain of Lactococcus lactis expressing human PAP (LL-PAP) could prevent and improve murine DNBS-induced colitis, an inflammatory bowel disease (IBD) that causes severe inflammation of the colon. Hence, in this study we sought to evaluate the protective effects of LL-PAP on 5-FU-induced experimental mucositis in BALB/c mice as a novel approach to treat the disease. RESULTS: Our results show that non-recombinant L. lactis NZ9000 have antagonistic activity, in vitro, against the enteroinvasive gastrointestinal pathogen L. monocytogenes and confirmed PAP inhibitory effect against Opportunistic E. faecalis. Moreover, L. lactis was able to prevent histological damage, reduce neutrophil and eosinophil infiltration and secretory Immunoglobulin-A in mice injected with 5-FU. Recombinant lactococci carrying antimicrobial PAP did not improve those markers of inflammation, although its expression was associated with villous architecture preservation and increased secretory granules density inside Paneth cells in response to 5-FU inflammation. CONCLUSIONS: We have demonstrated for the first time that L. lactis NZ9000 by itself, is able to prevent 5-FU-induced intestinal inflammation in BALB/c mice. Moreover, PAP delivered by recombinant L. lactis strain showed additional protective effects in mice epithelium, revealing to be a promising strategy to treat intestinal mucositis.
Assuntos
Antígenos de Neoplasias/genética , Antígenos de Neoplasias/metabolismo , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Ileíte/prevenção & controle , Lactococcus lactis/genética , Lactococcus lactis/fisiologia , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Mucosite/prevenção & controle , Animais , Antibiose , Antígenos de Neoplasias/farmacologia , Biomarcadores Tumorais/farmacologia , Modelos Animais de Doenças , Enterococcus faecalis/fisiologia , Fluoruracila , Humanos , Ileíte/induzido quimicamente , Ileíte/tratamento farmacológico , Doenças Inflamatórias Intestinais/tratamento farmacológico , Doenças Inflamatórias Intestinais/prevenção & controle , Mucosa Intestinal/metabolismo , Intestino Delgado/imunologia , Intestino Delgado/microbiologia , Intestino Delgado/patologia , Lactococcus lactis/metabolismo , Listeria monocytogenes/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Mucosite/induzido quimicamente , Mucosite/tratamento farmacológico , Mucosite/microbiologia , Proteínas Associadas a PancreatiteRESUMO
The inflammation induced by obesogenic diets is associated with deposition of fat in the liver. On the other hand, anti-inflammatory and immunosuppressive therapies may impact in body fat storage and in liver lipid dynamics. It is important to study specific inflammatory mediators in this context, since their role on hepatic damage is not fully clarified. This study aimed to evaluate the role of interleukin (IL)-18 and tumor necrosis factor (TNF) receptor in liver dysfunction induced by diet. Male C57BL/6 wild-type (WT), IL-18, and TNF receptor 1 knockout mice (IL-18-/- and TNFR1-/-) were divided according to the experimental diets: chow diet or a high-refined carbohydrate-containing diet. Alanine aminotransferase was quantified by colorimetric analysis. Total fat content in the liver was determined by Folch methods. Levels of TNF, IL-6, IL-4, and IL-13 in liver samples were measured by ELISA assay. IL-18 and TNFR knockout mice fed with chow diet showed higher liver triglycerides deposition than WT mice fed with the same diet (WT: 131.9 ± 24.5; IL-18-/-: 239.4 ± 38.12*; TNF-/-: 179.6 ± 50.45*; *P < 0.01). Furthermore, these animals also showed a worse liver histopathological score and lower levels of TNF, IL-6, IL-4, and IL-13 in the liver. Interestingly, treatment with a high-carbohydrate diet did not exacerbate liver damage in IL-18-/- and TNFR1-/- mice. Our data suggest that IL-18 and TNF may be involved on hepatic homeostasis mainly in a context of a healthy diet.
Assuntos
Interleucina-18/metabolismo , Metabolismo dos Lipídeos , Fígado/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Receptores Tipo I de Fatores de Necrose Tumoral/agonistas , Transdução de Sinais , Fator de Necrose Tumoral alfa/metabolismo , Animais , Biomarcadores/sangue , Biomarcadores/metabolismo , Colágeno/metabolismo , Dieta da Carga de Carboidratos/efeitos adversos , Manipulação de Alimentos , Inflamassomos/metabolismo , Interleucina-13/metabolismo , Interleucina-18/genética , Interleucina-4/metabolismo , Interleucina-6/metabolismo , Fígado/imunologia , Fígado/patologia , Fígado/fisiopatologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/imunologia , Hepatopatia Gordurosa não Alcoólica/patologia , Receptores Tipo I de Fatores de Necrose Tumoral/genética , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo , Triglicerídeos/metabolismoRESUMO
Hepatic diseases are comorbidities caused by obesity and are influenced by diet composition. The aim of this study was to evaluate the kinetics of metabolic and inflammatory liver dysfunction induced by a high-refined carbohydrate-containing (HC) diet and to determine how platelet-activating factor (PAF) modulates the liver lipid content of mice. BALB/c mice were fed a chow or HC diet for the following experimental periods: 1 and 3 days, 1, 2, 4, 6, 8, 10 and 12 weeks. Wild-type (WT) and PAF receptor-deficient (PAFR(-/-)) mice were fed the same diets for 8 weeks. Mice fed with HC diet showed higher triglycerides and cholesterol levels, fibrosis and inflammation in the liver. The number of neutrophils migrating into the liver was also increased in mice fed with HC diet. However, transaminase levels did not change. PAFR(-/-) mice fed with HC diet showed more steatosis, oxidative stress and higher transaminases levels associated with lower inflammation than WT mice. The consumption of HC diet altered the metabolic and inflammatory response in the liver and was worse in PAFR(-/-) mice. We suggest that PAF regulates liver lipid content and dyslipidemia, protecting the mice from lipotoxicity and liver damage.