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BACKGROUND: Colorectal cancer (CRC) has a high mortality rate and can develop in either colitis-dependent (colitis-associated (CA)-CRC) or colitis-independent (sporadic (s)CRC) manner. There has been a significant debate about whether mast cells (MCs) promote or inhibit the development of CRC. Herein we investigated MC activity throughout the multistepped development of CRC in both human patients and animal models. METHODS: We analyzed human patient matched samples of healthy colon vs CRC tissue alongside conducting a The Cancer Genome Atlas-based immunogenomic analysis and multiple experiments employing genetically engineered mouse (GEM) models. RESULTS: Analyzing human CRC samples revealed that MCs can be active or inactive in this disease. An activated MC population decreased the number of tumor-residing CD8 T cells. In mice, MC deficiency decreased the development of CA-CRC lesions, while it increased the density of tumor-based CD8 infiltration. Furthermore, co-culture experiments revealed that tumor-primed MCs promote apoptosis in CRC cells. In MC-deficient mice, we found that MCs inhibited the development of sCRC lesions. Further exploration of this with several GEM models confirmed that different immune responses alter and are altered by MC activity, which directly alters colon tumorigenesis. Since rescuing MC activity with bone marrow transplantation in MC-deficient mice or pharmacologically inhibiting MC effects impacts the development of sCRC lesions, we explored its therapeutic potential against CRC. MC activity promoted CRC cell engraftment by inhibiting CD8+ cell infiltration in tumors, pharmacologically blocking it inhibits the ability of allograft tumors to develop. This therapeutic strategy potentiated the cytotoxic activity of fluorouracil chemotherapy. CONCLUSION: Therefore, we suggest that MCs have a dual role throughout CRC development and are potential druggable targets against this disease.
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Colite , Neoplasias Colorretais , Animais , Fluoruracila , Humanos , Mastócitos , CamundongosRESUMO
BACKGROUND: Trypanosoma cruzi (T. cruzi) infects millions of Latin Americans each year and can induce chagasic megacolon. Little is known about how serotonin (5-HT) modulates this condition. Aim We investigated whether 5-HT synthesis alters T. cruzi infection in the colon. MATERIALS AND METHODS: Forty-eight paraffin-embedded samples from normal colon and chagasic megacolon were histopathologically analyzed (173/2009). Tryptophan hydroxylase 1 (Tph1) knockout (KO) mice and c-KitW-sh mice underwent T. cruzi infection together with their wild-type counterparts. Also, mice underwent different drug treatments (16.1.1064.60.3). RESULTS: In both humans and experimental mouse models, the serotonergic system was activated by T. cruzi infection (p < 0.05). While treating Tph1KO mice with 5-HT did not significantly increase parasitemia in the colon (p > 0.05), rescuing its synthesis promoted trypanosomiasis (p < 0.01). T. cruzi-related 5-HT release (p < 0.05) seemed not only to increase inflammatory signaling, but also to enlarge the pericryptal macrophage and mast cell populations (p < 0.01). Knocking out mast cells reduced trypanosomiasis (p < 0.01), although it did not further alter the neuroendocrine cell number and Tph1 expression (p > 0.05). Further experimentation revealed that pharmacologically inhibiting mast cell activity reduced colonic infection (p < 0.01). A similar finding was achieved when 5-HT synthesis was blocked in c-KitW-sh mice (p > 0.05). However, inhibiting mast cell activity in Tph1KO mice increased colonic trypanosomiasis (p < 0.01). CONCLUSION: We show that mast cells may modulate the T. cruzi-related increase of 5-HT synthesis in the intestinal colon.
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Doença de Chagas/metabolismo , Colo/metabolismo , Enteropatias Parasitárias/metabolismo , Mastócitos/metabolismo , Megacolo/metabolismo , Serotonina/biossíntese , Trypanosoma cruzi/patogenicidade , Adulto , Idoso , Animais , Estudos de Casos e Controles , Doença de Chagas/genética , Doença de Chagas/parasitologia , Colo/parasitologia , Interações Hospedeiro-Patógeno , Humanos , Enteropatias Parasitárias/genética , Enteropatias Parasitárias/parasitologia , Masculino , Mastócitos/parasitologia , Megacolo/genética , Megacolo/parasitologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Proteínas Proto-Oncogênicas c-kit/genética , Proteínas Proto-Oncogênicas c-kit/metabolismo , Fatores de Tempo , Triptofano Hidroxilase/genética , Triptofano Hidroxilase/metabolismoRESUMO
During the course of Chagas disease, infectious forms of Trypanosoma cruzi are occasionally liberated from parasitized heart cells. Studies performed with tissue culture trypomastigotes (TCTs, Dm28c strain) demonstrated that these parasites evoke neutrophil/CXCR2-dependent microvascular leakage by activating innate sentinel cells via toll-like receptor 2 (TLR2). Upon plasma extravasation, proteolytically derived kinins and C5a stimulate immunoprotective Th1 responses via cross-talk between bradykinin B2 receptors (B2Rs) and C5aR. Awareness that TCTs invade cardiovascular cells in vitro via interdependent activation of B2R and endothelin receptors [endothelin A receptor (ETAR)/endothelin B receptor (ETBR)] led us to hypothesize that T. cruzi might reciprocally benefit from the formation of infection-associated edema via activation of kallikrein-kinin system (KKS). Using intravital microscopy, here we first examined the functional interplay between mast cells (MCs) and the KKS by topically exposing the hamster cheek pouch (HCP) tissues to dextran sulfate (DXS), a potent "contact" activator of the KKS. Surprisingly, although DXS was inert for at least 30 min, a subtle MC-driven leakage resulted in factor XII (FXII)-dependent activation of the KKS, which then amplified inflammation via generation of bradykinin (BK). Guided by this mechanistic insight, we next exposed TCTs to "leaky" HCP-forged by low dose histamine application-and found that the proinflammatory phenotype of TCTs was boosted by BK generated via the MC/KKS pathway. Measurements of footpad edema in MC-deficient mice linked TCT-evoked inflammation to MC degranulation (upstream) and FXII-mediated generation of BK (downstream). We then inoculated TCTs intracardiacally in mice and found a striking decrease of parasite DNA (quantitative polymerase chain reaction; 3 d.p.i.) in the heart of MC-deficient mutant mice. Moreover, the intracardiac parasite load was significantly reduced in WT mice pretreated with (i) cromoglycate (MC stabilizer) (ii) infestin-4, a specific inhibitor of FXIIa (iii) HOE-140 (specific antagonist of B2R), and (iv) bosentan, a non-selective antagonist of ETAR/ETBR. Notably, histopathology of heart tissues from mice pretreated with these G protein-coupled receptors blockers revealed that myocarditis and heart fibrosis (30 d.p.i.) was markedly and redundantly attenuated. Collectively, our study suggests that inflammatory edema propagated via activation of the MC/KKS pathway fuels intracardiac parasitism by generating infection-stimulatory peptides (BK and endothelins) in the edematous heart tissues.
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Quantitative alterations in mast cell numbers in pancreatic lymph nodes (PLNs) have been reported to be associated with type 1 diabetes (T1D) progression, but their potential role during T1D remains unclear. In this study, we evaluated the role of mast cells in T1D induced by multiple low-dose streptozotocin (MLD-STZ) treatments, using two strains of mast cell-deficient mice (W/W(v) or Wsh/Wsh) and the adoptive transfer of mast cells. Mast cell deficient mice developed severe insulitis and accelerated hyperglycemia, with 100% of mice becoming diabetic compared to their littermates. In parallel, these diabetic mice had decreased numbers of T regulatory (Treg) cells in the PLNs. Additionally, mast cell deficiency caused a significant reduction in IL-10, TGF-ß, and IL-6 expression in the pancreatic tissue. Interestingly, IL-6-deficient mice are more susceptible to T1D associated with reduced Treg-cell numbers in the PLNs, but mast cell transfer from wild-type mice induced protection to T1D in these mice. Finally, mast cell adoptive transfer prior to MLD-STZ administration conferred resistance to T1D, promoted increased Treg cells, and decreased IL-17-producing T cells in the PLNs. Taken together, our results indicate that mast cells are implicated in resistance to STZ-induced T1D via an immunological tolerance mechanism mediated by Treg cells.
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Diabetes Mellitus Experimental/imunologia , Diabetes Mellitus Tipo 1/imunologia , Regulação da Expressão Gênica/imunologia , Mastócitos/imunologia , Linfócitos T Reguladores/imunologia , Animais , Citocinas/genética , Citocinas/imunologia , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/patologia , Mastócitos/patologia , Camundongos , Camundongos Knockout , Linfócitos T Reguladores/patologia , Células Th17/imunologia , Células Th17/patologiaRESUMO
INTRODUCTION AND OBJECTIVES: Chagas disease is a prevalent cause of heart failure in Latin America, and its prognosis is worse than other etiologies. The Heart Failure Survival Score has been used to assess prognosis in patients with heart failure; however, this score has not yet been studied in patients with Chagas cardiopathy. METHODS: The Heart Failure Survival Score was calculated in 55 patients with severe left ventricular systolic dysfunction due to Chagas disease. Correlations were assessed between the Heart Failure Survival Score and variables obtained from, cardiopulmonary exercise tests, quality-of-life measures, and 6-minute walking tests. RESULTS: Patients were distributed among New York Heart Association classes II-IV; 89% were taking angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, 62% were taking beta-blockers, 86% were taking diuretics, and 74% were taking aldosterone receptor blockers. The mean Heart Failure Survival Score was 8.75 (0.80). The score correlated well with cardiopulmonary test variables such as peak oxygen uptake (0.662; P<.01), oxygen uptake at the anaerobic threshold (0.644; P<.01), ventilation carbon dioxide efficiency slope (-0.417; P<.01), oxygen pulse (0.375; P<.01), oxygen uptake efficiency slope (0.626; P<.01), 6-minute walking test (0.370; P<.01), left ventricle ejection fraction (0.650; P=.01), and left atrium diameter (-0.377; P<.01). There was also a borderline significant correlation between the Heart Failure Survival Score and quality of life (-0.283; P<.05). CONCLUSIONS: In heart failure patients with Chagas disease, the Heart Failure Survival Score correlated well with the main prognostic functional test variables.
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Cardiomiopatia Chagásica/mortalidade , Insuficiência Cardíaca/mortalidade , Disfunção Ventricular Esquerda/mortalidade , Antagonistas Adrenérgicos beta/uso terapêutico , Adulto , Idoso , Antagonistas de Receptores de Angiotensina/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Cardiomiopatia Chagásica/complicações , Cardiomiopatia Chagásica/fisiopatologia , Ecocardiografia , Teste de Esforço/métodos , Feminino , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/etiologia , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Qualidade de Vida , Análise de Sobrevida , Disfunção Ventricular Esquerda/tratamento farmacológico , Disfunção Ventricular Esquerda/etiologia , Disfunção Ventricular Esquerda/fisiopatologia , Adulto JovemRESUMO
INTRODUCTION: The objective of this study was to investigate regional organ perfusion acutely following uncontrolled hemorrhage in an animal model that simulates a penetrating vascular injury and accounts for prehospital times in urban trauma. We set forth to determine if hypotensive resuscitation (permissive hypotension) would result in equivalent organ perfusion compared to normotensive resuscitation. METHODS: Twenty four (n=24) male rats randomized to 4 groups: Sham, No Fluid (NF), Permissive Hypotension (PH) (60% of baseline mean arterial pressure - MAP), Normotensive Resuscitation (NBP). Uncontrolled hemorrhage caused by a standardised injury to the abdominal aorta; MAP was monitored continuously and lactated Ringer's was infused. Fluorimeter readings of regional blood flow of the brain, heart, lung, kidney, liver, and bowel were obtained at baseline and 85 minutes after hemorrhage, as well as, cardiac output, lactic acid, and laboratory tests; intra-abdominal blood loss was assessed. Analysis of variance was used for comparison. RESULTS: Intra-abdominal blood loss was higher in NBP group, as well as, lower hematocrit and hemoglobin levels. No statistical differences in perfusion of any organ between PH and NBP groups. No statistical difference in cardiac output between PH and NBP groups, as well as, in lactic acid levels between PH and NBP. NF group had significantly higher lactic acidosis and had significantly lower organ perfusion. CONCLUSIONS: Hypotensive resuscitation causes less intra-abdominal bleeding than normotensive resuscitation and concurrently maintains equivalent organ perfusion. No fluid resuscitation reduces intra-abdominal bleeding but also significantly reduces organ perfusion.
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BACKGROUND: The molecules that provide access to activated T cells in the CNS, including chemokines, have been considered to be a crucial step in the pathogenesis of multiple sclerosis (MS). AIMS: In this study, we investigated serial serum chemokine levels in patients with relapsing-remitting MS over 1 year and the association of these chemokine levels with treatment regimens, lesions on MRI and patients' characteristics. METHODS: Serum CXCL9, CXCL10, CCL2, CCL4 and CCL5 levels were evaluated using ELISA every 2 months for a year in 28 healthy controls and 28 MS patients during their treatment with interferon (IFN)-ß. Patients underwent MRI and were evaluated using the Expanded Disability Status Scale (EDSS) at the first and final evaluations. RESULTS: CXCL10 serum levels were higher in MS patients compared with controls, were positively correlated with T2 lesions on MRI and were slightly increased during relapses. Treatment with IFNß-1a or IFNß-1b was associated with increased CXCL10 levels when evaluated more than 36 hours after subcutaneous injection. The CXCL9 levels were higher after MS relapse. There was significant variability in CCL4 and CCL5 levels in the serial evaluations, associated with gender and treatment. CCL2 levels were higher in treated MS patients than healthy controls, particularly among those patients with a stable form of the disease. CONCLUSION: Serum is a feasible resource for searching for an immunological marker in MS. Peripheral chemokine levels correlated in different ways with IFNß therapy and with disease and patient characteristics. CLINICAL TRIAL REGISTRATION NUMBER: ISRCTN45526724.
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Adjuvantes Imunológicos/uso terapêutico , Quimiocinas/sangue , Fatores Imunológicos/uso terapêutico , Interferon beta/uso terapêutico , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Esclerose Múltipla/tratamento farmacológico , Adjuvantes Imunológicos/efeitos adversos , Adulto , Quimiocina CCL2/sangue , Quimiocina CCL4/sangue , Quimiocina CCL5/sangue , Quimiocina CXCL10/sangue , Quimiocina CXCL9/sangue , Estudos de Coortes , Feminino , Humanos , Fatores Imunológicos/efeitos adversos , Injeções Subcutâneas , Interferon beta/efeitos adversos , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/sangue , Prevenção Secundária , Adulto JovemRESUMO
BACKGROUND: The study of the endotoxin tolerance phenomenon in light of the recently defined roles of mast cells and toll-like receptors as essential components of the innate immune response and as orchestrators of acquired immunity may reveal potentially useful mechanisms of immunomodulation of infectious and allergic inflammatory responses, such as sepsis or asthma. Here we evaluated the phenomenon of direct tolerance of endotoxins, as well as the induction of cross-tolerance and synergism by stimulation with toll-like receptor-2 (TLR2) and FcepsilonR1 agonists, in murine mast cells prestimulated with lipopolysaccharide (LPS). Additionally, we evaluated some stimulatory and inhibitory signaling molecules potentially involved in these phenomena. METHODS: MC/9 cells and primary bone marrow-derived mast cells obtained from C57BL/6 and TLR4-/- knock-out mice were sensitized to DNP-HSA (antigen) by incubation with DNP-IgE and were prestimulated with LPS for 18 hr prior to stimulation. Cultures were stimulated with LPS or Pam3Cys-Ser-(Lys)4 3HCl (P3C), a TLR2 agonist, individually or in combination with antigen. The production of IL-6 and TNFalpha, the phosphorylation of NFkappaB and p38 MAPK, and the expression of TLR4 and SOCS-1 and -3 were analyzed. RESULTS: We found that production of TNFalpha and IL-6 in murine mast cells that have been pretreated with LPS and challenged with TLR4 (LPS) or -2 (P3C) agonists was reduced, phenomena described as endotoxin tolerance (LPS) and cross-tolerance (P3C), respectively. The expression of TLR4 was not affected by LPS pretreatment. Our results show that the FcepsilonR1 agonist DNP-HSA (antigen) interacts synergistically with LPS or P3C to markedly enhance production of cytokines (TNFalpha and IL-6). This synergistic effect with LPS and P3C was also attenuated by LPS pretreatment and was mediated by TLR4. These results may be attributed to the reduction in phosphorylation of the mitogen-activated protein kinase (MAPK), p38, and the transcription factor NFkappaB, as well as to an increase in the expression of the suppressors of cytokine signaling (SOCS)-1 and -3 proteins in LPS-pretreated mast cells. CONCLUSIONS: These findings can be explored with respect to the modulation of inflammatory responses associated with infectious and allergic processes in future studies.
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Endotoxinas/imunologia , Mastócitos/imunologia , Receptores de IgE/imunologia , Proteínas Supressoras da Sinalização de Citocina/biossíntese , Receptor 2 Toll-Like/imunologia , Receptor 4 Toll-Like/biossíntese , Animais , Células Cultivadas , Endotoxinas/toxicidade , Imunomodulação , Interleucina-6/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Fosforilação , Receptores de IgE/agonistas , Receptor 2 Toll-Like/agonistas , Fator de Necrose Tumoral alfa/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
Heart failure due to Chagas cardiomyopathy (HFCC) differs from failure with other etiologies because of the occurrence of intense inflammatory infiltrate and right ventricle compromise. This article investigates correlations of B-type natriuretic peptide (BNP) levels with parameters of severity in HFCC. Twenty-eight patients and 8 normal controls underwent heart catheterization and clinical and laboratory analyses. BNP levels were higher in patients with HFCC (P<.0001) and correlated with New York Heart Association (NYHA) class; right atrial pressure; wedge pressure; cardiac output; levels of serum sodium, hemoglobin, urea, and tumor necrosis factor-alpha; and ejection fraction. Interferon-gamma and transforming growth factor-beta did not correlate with BNP level. The authors conclude that BNP levels are elevated in patients experiencing HFCC, irrespective of NYHA class, and that the occurrence of HFCC correlates with severity of disease.
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Cardiomiopatia Chagásica/complicações , Insuficiência Cardíaca/etiologia , Peptídeo Natriurético Encefálico/sangue , Cateterismo Cardíaco , Estudos de Casos e Controles , Cardiomiopatia Chagásica/sangue , Cardiomiopatia Chagásica/fisiopatologia , Diástole , Tolerância ao Exercício , Feminino , Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/fisiopatologia , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Medição de Risco , Fatores de Risco , Inquéritos e Questionários , SístoleRESUMO
OBJETIVO: Descrever técnica de curativo para cobertura temporária da cavidade abdominal que utiliza sistema de vácuo. MÉTODO: A técnica foi aplicada em 12 pacientes. Inicialmente coloca-se sobre a laparostomia a bolsa plástica fenestrada, em seguida a primeira camada de compressas. Sobre esta, coloca-se o tubo de látex. Este é recoberto por outra camada de compressas as quais são fixadas sobre o curativo com o campo cirúrgico auto-aderente. O tubo de látex é conectado ao sistema de vácuo com pressão de -10 a -50 mmHg. Trocam-se os curativos a cada 12 horas. Material utilizado bolsa plástica de solução salina, compressas cirúrgicas, tubo de látex, campo cirúrgico auto-aderente de 50cm x 30cm e vácuo do sistema de gases hospitalares. RESULTADOS:A peritonite grave foi a indicação mais freqüente para laparostomia, seguida da síndrome de compartimento abdominal. Fechamento definitivo da cavidade abdominal foi possível em oito pacientes (67 por cento) em média após 11 dias (9 a 21 dias) da laparostomia. Não houve complicações associadas ao método. O custo diário aproximado do curativo foi de R$ 50,00. CONCLUSÃO: O curativo a vácuo proporcionou boa contenção das vísceras abdominais, controlou o extravasamento de secreções e o edema. Permitiu o fechamento definitivo da cavidade abdominal na maioria dos casos e foi de baixo custo.
BACKGROUND: We describe a vacuum pack technique for a temporary abdominal wound closure. METHODS: The vacuum pack materials were a plastic sheet, laparotomy pads, latex tube, 50cm x 30cm adhesive-backed plastic, and a vacuum source. Twelve patients underwent the procedure as follows: we cut several slits in the plastic sheet, which is applied directly over the abdominal contents. We put laparotomy pads over the plastic sheet, and then a latex tube is placed over the laparotomy pads. Another layer of laparotomy pads is placed over the latex tube, which is stuck by an adhesive-backed plastic. We connect the tube to a vacuum source with negative pressure between -10 to -50 mmHg. The pack is changed every 12 hours. RESULTS: Severe peritonitis was the most common indication followed by the abdominal compartment syndrome. Definitive abdominal closure was performed in eight patients (67 percent) after an average of 11 days (9 to 21 days) from the first day of laparostomy. There were no complications directly associated with the method. Daily cost was approximately R$ 50.00. CONCLUSION: The vacuum pack kept the underlying abdominal viscera secure beneath the dressing; in addition, it controlled fluid leakage and edema. Definitive abdominal wound closure was possible in the majority of the patients. This was achieved at a reasonable financial cost.