RESUMO
Tuberculosis (TB) has been declared the first cause of death by an infectious agent. Annually, 10.4 million people suffer active TB. Most infected individuals live in low-income countries, where social and economic conditions enhance the dissemination and progression of the disease. These countries have a high percentage of smokers. Thousands of studies have linked cigarette smoke (CS) with increased risk of many diseases, such as cancer and lung diseases. Numerous in vitro studies have been conducted to evaluate the general and specific toxic effects of CS in lung immune function. Smoke exposure increases the risk of TB development three-fold. However, until now, only few animal studies have been performed to analyze the association between smoke and TB. In the present work, we review in vitro and in vivo studies whose aim was to analyze the molecular basis of TB susceptibility caused by exposure to CS.
Assuntos
Poluição por Fumaça de Tabaco/efeitos adversos , Tuberculose/etiologia , Animais , Fumar Cigarros/efeitos adversos , HumanosRESUMO
It is well known that vitamin A and its receptors protect against cancer development and that Retinoid Acid Receptor ß (RARß) is epigenetically silenced during tumoral progression. Cervical Cancer (CC) has been causally linked to high risk human papillomavirus (HR-HPV) infection. However, host factors are important in determining the outcome of persistent HR-HPV infection as most cervical precancerous lesions containing HR-HPVs do not progress to invasive carcinomas. Increasing evidence suggests that low diet in vitamin A and their receptors participate in the development of CC. The aim of this study has been to investigate the effects of abated RARß expression in the development of cervical premalignant lesions in 4 month-old conditional mice (RARß(L-/L-)). Results demonstrated the development of spontaneous squamous metaplasia, inflammatory infiltrate, enhanced mitotic activity, loss of cell differentiation, as well as decreased apoptosis and p16(INK4a) protein levels in RARß(L-/L-) mice cervix. All these changes are hallmarks of moderate dysplasia. Importantly, our results suggest that the low expression of RARß, may induce the down regulation of p16(INK4a), chronic inflammation and decreased apoptosis and may be involved in vulnerability to HR-HPV and early stage cervical carcinogenesis.
Assuntos
Inflamação/patologia , Lesões Pré-Cancerosas/patologia , Receptores do Ácido Retinoico/metabolismo , Neoplasias do Colo do Útero/patologia , Animais , Apoptose , Proliferação de Células , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Colo do Útero/patologia , Inibidor p16 de Quinase Dependente de Ciclina/genética , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Feminino , Imunofluorescência , Deleção de Genes , Humanos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores do Ácido Retinoico/genética , Displasia do Colo do Útero/patologia , Vagina/patologiaRESUMO
Airway inflammation is the most common hallmark of allergic asthma. Chemokine receptors involved in leukocyte recruitment are closely related to the pathology in asthma. CCR9 has been described as a homeostatic and inflammatory chemokine receptor, but its role and that of its ligand CCL25 during lung inflammation remain unknown. To investigate the role of CCR9 as a modulator of airway inflammation, we established an OVA-induced allergic inflammation model in CCR9-deficient mice. Here, we report the expression of CCR9 and CCL25 as early as 6 hours post-OVA challenge in eosinophils and T-lymphocytes. Moreover, in challenged CCR9-deficient mice, cell recruitment was impaired at peribronchial and perivenular levels. OVA-administration in CCR9-deficient mice leads to a less inflammatory cell recruitment, which modifies the expression of IL-10, CCL11, and CCL25 at 24 hours after OVA challenge. In contrast, the secretion of IL-4 and IL-5 was not affected in CCR9-deficient mice compared to WT mice. These results demonstrate for the first time that CCR9 and CCL25 expressions are induced in the early stages of airway inflammation and they have an important role modulating eosinophils and lymphocytes recruitment at the first stages of inflammatory process, suggesting that they might be a potential target to regulate inflammation in asthma.
Assuntos
Quimiocinas CC/metabolismo , Regulação da Expressão Gênica , Hipersensibilidade/metabolismo , Inflamação/metabolismo , Receptores CCR/metabolismo , Animais , Líquido da Lavagem Broncoalveolar , Separação Celular , Citocinas/metabolismo , Ensaio de Imunoadsorção Enzimática , Eosinófilos/citologia , Feminino , Citometria de Fluxo , Imunoglobulina E/sangue , Leucócitos/citologia , Pulmão/fisiopatologia , Linfócitos/citologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Linfócitos T/citologiaRESUMO
BACKGROUND: Helicobacter pylori (H. pylori) is the main risk factor for the development of chronic gastritis, gastric ulcer, and gastric cancer. In H. pylori-infected individuals, the clinical result is dependent on various factors, among which are bacterial components, the immune response, and environmental influence. AIMS: To compare IFN-γ expression with the H. pylori vacA and cagA genotypes in patients with chronic gastritis and patients with gastric cancer. METHODS: Ninety-five patients diagnosed with chronic gastritis and 20 with gastric cancer were included in the study. Three gastric biopsies were taken; one was used for the molecular detection and genotyping of H. pylori; another was fixed in absolute alcohol and histologic sections were made for determining IFN-γ expression through immunohistochemistry. RESULTS: No differences were found in the cells that expressed IFN-γ between the patients with chronic gastritis (median percentage of positive cells: 82.6% in patients without H. pylori and 82% in infected persons) and those with gastric cancer (70.5% in H. pylori-negative patients and 78.5% in infected persons). IFN-γ expression was 69% in chronic gastritis patients infected with H. pylori vacAs2m2/cagAâ» it was 86.5% in patients infected with H. pylori vacAs1m2/cagAâ», 86.5% in vacAs1m1/cagAâ», and 82% in vacAs1m1/cagAâº. Similar data were found in the patients with gastric cancer. CONCLUSIONS: IFN-γ expression varied depending on the H. pylori vacA and cagA genotype, but not in accordance with the presence of chronic gastritis or gastric cancer.
Assuntos
Gastrite/metabolismo , Gastrite/microbiologia , Helicobacter pylori/genética , Interferon gama/biossíntese , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/microbiologia , Adulto , Idoso , Doença Crônica , Feminino , Genes Bacterianos/genética , Variação Genética , Genótipo , Infecções por Helicobacter/microbiologia , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
BALB/c mice with pulmonary tuberculosis (TB) develop a T helper cell type 1 that temporarily controls bacterial growth. Bacterial proliferation increases, accompanied by decreasing expression of interferon (IFN)-γ, tumour necrosis factor (TNF)-α and inducible nitric oxide synthase (iNOS). Activation of dendritic cells (DCs) is delayed. Intratracheal administration of only one dose of recombinant adenoviruses encoding granulocyte-macrophage colony-stimulating factor (AdGM-CSF) 1 day before Mycobacterium tuberculosis (Mtb) infection produced a significant decrease of pulmonary bacterial loads, higher activated DCs and increased expression of TNF-α, IFN-γ and iNOS. When AdGM-CSF was given in female mice B6D2F1 (C57BL/6J X DBA/2J) infected with a low Mtb dose to induce chronic infection similar to latent infection and corticosterone was used to induce reactivation, a very low bacilli burden in lungs was detected, and the same effect was observed in healthy mice co-housed with mice infected with mild and highly virulent bacteria in a model of transmissibility. Thus, GM-CSF is a significant cytokine in the immune protection against Mtb and gene therapy with AdGM-CSF increased protective immunity when administered in a single dose 1 day before Mtb infection in a model of progressive disease, and when used to prevent reactivation of latent infection or transmission.
Assuntos
Adenoviridae/genética , Fator Estimulador de Colônias de Granulócitos e Macrófagos/genética , Fator Estimulador de Colônias de Granulócitos e Macrófagos/imunologia , Tuberculose Pulmonar/terapia , Animais , Modelos Animais de Doenças , Feminino , Terapia Genética , Imunoterapia , Pulmão/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Tuberculose Pulmonar/genética , Tuberculose Pulmonar/imunologia , Tuberculose Pulmonar/transmissãoRESUMO
Candida albicans causes opportunistic systemic infections with high mortality (30%-50%). Despite significant nephrotoxicity, amphotericin (AmB) is still used for the treatment of this serious fungal infection. Therefore, alternative treatments are urgently needed. Dialyzable leukocyte extracts have been used successfully to treat patients with mucocutaneous candidiasis, but their effectiveness in systemic candidiasis has not been evaluated. In this study, low-dose AmB (0.1 mg/kg) plus 10 pg of murine dialyzable spleen extracts (mDSE) were tested in a systemic candidiasis mouse model. Survival, tissue fungal burden, kidney damage, kidney cytokines, and serum levels of IL-6 and hepcidin were evaluated. Our results showed that the combined treatment of low-dose AmB plus mDSE improved survival and reduced kidney fungal burden and histopathology; these effects correlated with increased kidney concentration of IFN- γ and TGF- ß 1, decreased levels of TNF- α , IL-6, and IL-10, as well as high levels of systemic IL-6 and hepcidin. Low-dose AmB and mDSE synergized to clear the infectious agent and reduced tissue damage, confirming the efficacy of a low dose of AmB, which might decrease the risk of drug toxicity. Further studies are necessary to explore these findings and its implications in future therapeutic approaches.
Assuntos
Anfotericina B/administração & dosagem , Antifúngicos/administração & dosagem , Candidíase/tratamento farmacológico , Linfocinas/administração & dosagem , Baço/metabolismo , Animais , Candidíase/mortalidade , Candidíase/patologia , Citocinas/biossíntese , Modelos Animais de Doenças , Feminino , Hepcidinas/biossíntese , Interleucina-6/biossíntese , Rim/metabolismo , Rim/microbiologia , CamundongosRESUMO
The thymus is the anatomical site where T cells undergo a complex process of differentiation, proliferation, selection, and elimination of autorreactive cells which involves molecular signals in different intrathymic environment. However, the immunological functions of the thymus can be compromised upon exposure to different infections, affecting thymocyte populations. In this work, we investigated the impact of malaria parasites on the thymus by using C57BL/6 mice infected with Plasmodium berghei ANKA and Plasmodium yoelii 17XL; these lethal infection models represent the most severe complications, cerebral malaria, and anemia respectively. Data showed a reduction in the thymic weight and cellularity involving different T cell maturation stages, mainly CD4-CD8- and CD4+CD8+ thymocytes, as well as an increased presence of apoptotic cells, leading to significant thymic cortex reduction. Thymus atrophy showed no association with elevated serum cytokines levels, although increased glucocorticoid levels did. The severity of thymic damage in both models reached the same extend although it occurs at different stages of infection, showing that thymic atrophy does not depend on parasitemia level but on the specific host-parasite interaction.
Assuntos
Malária , Plasmodium yoelii , Animais , Camundongos , Plasmodium berghei , Camundongos Endogâmicos C57BL , Atrofia , ParasitemiaRESUMO
AIMS/HYPOTHESIS: Liver X receptor (LXR)α regulates the genes involved in cholesterol, fatty acid and glucose metabolism. Soy protein (SP) consumption reduces the hepatic accumulation of cholesterol and triacylglycerol, and improves insulin sensitivity. However, it is not known whether these effects are mediated via LXRα. We therefore investigated whether the consumption of SP regulates metabolic changes in cholesterol metabolism and insulin sensitivity via LXRα. METHODS: Wild-type (WT) and Lxrα(-/-) (Lxrα, also known as Nr1h3) mice were fed an SP diet with or without cholesterol for 28 days. The expression of LXRα target genes was measured in liver and intestine, as were hepatic lipid content and faecal bile acid concentration. Oral glucose and insulin tolerance tests were also performed. Hepatocytes were used to study the effect of isoflavones on LXR activity. RESULTS: The livers of WT and Lxrα(-/-) mice fed an SP high-cholesterol diet showed less steatosis than those fed casein. The SP diet increased the expression of the ATP-binding cassette (ABC) sub-family genes Abca1, Abcg5 and Abcg8 in the liver and intestine, as well as increasing total faecal bile acid excretion and insulin sensitivity in WT mice compared with mice fed a casein diet. However, these effects of SP were not observed in Lxrα(-/-) mice. The SP isoflavone, genistein, repressed the activation of LXRα target genes by T0901317, whereas it stimulated the activation of LXRß target genes. The AMP-activated protein kinase inhibitor, compound C, had the opposite effects to those of genistein. CONCLUSIONS/INTERPRETATION: Our results suggest that SP isoflavones stimulate the phosphorylation of LXRα or LXRß, resulting in different biological effects for each LXR isoform.
Assuntos
Hepatócitos/metabolismo , Mucosa Intestinal/metabolismo , Metabolismo dos Lipídeos , Fígado/metabolismo , Receptores Nucleares Órfãos , Proteínas de Soja/farmacologia , Animais , Ácidos e Sais Biliares/metabolismo , Transporte Biológico , Dieta Hiperlipídica , Regulação da Expressão Gênica , Hepatócitos/efeitos dos fármacos , Resistência à Insulina , Isoflavonas/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Receptores X do Fígado , Masculino , Camundongos , Camundongos Transgênicos , Receptores Nucleares Órfãos/efeitos dos fármacos , Receptores Nucleares Órfãos/metabolismo , Isoformas de Proteínas/metabolismoRESUMO
Inhibition of the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase enhances the neural vulnerability to excitotoxicity both in vivo and in vitro through an unknown mechanism possibly related to mitochondrial failure. However, as the effect of glycolysis inhibition on mitochondrial function in brain has not been studied, the aim of the present work was to evaluate the effect of glycolysis inhibition induced by iodoacetate on mitochondrial function and oxidative stress in brain. Mitochondria were isolated from brain cortex, striatum and cerebellum of rats treated systemically with iodoacetate (25 mg/kg/day for 3 days). Oxygen consumption, ATP synthesis, transmembrane potential, reactive oxygen species production, lipoperoxidation, glutathione levels, and aconitase activity were assessed. Oxygen consumption and aconitase activity decreased in the brain cortex and striatum, showing that glycolysis inhibition did not trigger severe mitochondrial impairment, but a slight mitochondrial malfunction and oxidative stress were present.
Assuntos
Encéfalo , Gliceraldeído-3-Fosfato Desidrogenases/metabolismo , Glicólise , Mitocôndrias , Trifosfato de Adenosina/biossíntese , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/enzimologia , Gliceraldeído-3-Fosfato Desidrogenases/antagonistas & inibidores , Glicólise/efeitos dos fármacos , Iodoacetatos/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/enzimologia , Consumo de Oxigênio/efeitos dos fármacos , Ratos , Espécies Reativas de Oxigênio/metabolismoRESUMO
Murine leprosy is a systemic infectious disease of mice caused by Mycobacterium lepraemurium (MLM) in which the central nervous system (CNS) is not infected; nevertheless, diseased animals show measurable cognitive alterations. For this reason, in this study, we explored the neurobehavioral changes in mice chronically infected with MLM. BALB/c mice were infected with MLM, and 120 days later, the alterations in mice were evaluated based on immunologic, histologic, endocrine, neurochemical, and behavioral traits. We found increases in the levels of IL-4 and IL-10 associated with high bacillary loads. We also found increase in the serum levels of corticosterone, epinephrine, and norepinephrine in the adrenal gland, suggesting neuroendocrine deregulation. Mice exhibited depression-like behavior in the tail suspension and forced swimming tests and anxiolytic behavior in the open field and elevated plus maze tests. The neurobehavioral alterations of mice were correlated with the histologic damage in the prefrontal cortex, ventral hippocampus, and amygdala, as well as with a blood-brain barrier disruption in the hippocampus. These results reveal an interrelated response of the neuroimmune--endocrinological axis in unresolved chronic infections that result in neurocognitive deterioration.
Assuntos
Ansiolíticos , Mycobacterium lepraemurium , Animais , Comportamento Animal/fisiologia , Corticosterona , Depressão , Camundongos , Camundongos Endogâmicos BALB CRESUMO
Tuberculosis is a worldwide health problem, and multidrug-resistant (MDR) and extensively multidrug-resistant (XMDR) strains are rapidly emerging and threatening the control of this disease. These problems motivate the search for new treatment strategies. One potential strategy is immunotherapy using cationic anti-microbial peptides. The capacity of l-isoleucine to induce beta-defensin expression and its potential therapeutic efficiency were studied in a mouse model of progressive pulmonary tuberculosis. BALB/c mice were infected with Mycobacterium tuberculosis strain H37Rv or with a MDR clinical isolate by the intratracheal route. After 60 days of infection, when disease was in its progressive phase, mice were treated with 250 µg of intratracheal l-isoleucine every 48 h. Bacillary loads were determined by colony-forming units, protein and cytokine gene expression were determined by immunohistochemistry and reverse transcription-quantitative polymerase chain reaction (RT-qPCR), respectively, and tissue damage was quantified by automated morphometry. Administration of l-isoleucine induced a significant increase of beta-defensins 3 and 4 which was associated with decreased bacillary loads and tissue damage. This was seen in animals infected with the antibiotic-sensitive strain H37Rv and with the MDR clinical isolate. Thus, induction of beta-defensins might be a potential therapy that can aid in the control of this significant infectious disease.
Assuntos
Imunoterapia/métodos , Isoleucina/farmacologia , Tuberculose/terapia , beta-Defensinas/imunologia , Animais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Imuno-Histoquímica , Isoleucina/administração & dosagem , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Pulmão/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/imunologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Tuberculose/imunologia , Tuberculose/microbiologia , Tuberculose Pulmonar/imunologia , Tuberculose Pulmonar/microbiologia , Tuberculose Pulmonar/terapia , beta-Defensinas/genética , beta-Defensinas/metabolismoRESUMO
BACKGROUND: New therapies are necessary to address inadequate asthma control in many patients. This study sets out to investigate whether hypoxia-inducible factor (HIF) is essential for development of allergic airway inflammation (AAI) and therefore a potential novel target for asthma treatment. METHODS: Mice conditionally knocked out for HIF-1ß were examined for their ability to mount an allergic inflammatory response in the lung after intratracheal exposure to ovalbumin. The effects of treating wild-type mice with either ethyl-3,4-dihydroxybenzoate (EDHB) or 2-methoxyestradiol (2ME), which upregulate and downregulate HIF, respectively, were determined. HIF-1α levels were also measured in endobronchial biopsies and bronchial fluid of patients with asthma and nasal fluid of patients with rhinitis after challenge. RESULTS: Deletion of HIF-1ß resulted in diminished AAI and diminished production of ovalbumin-specific IgE and IgG(1) . EDHB enhanced the inflammatory response, which was muted upon simultaneous inhibition of vascular endothelial growth factor (VEGF). EDHB and 2ME antagonized each other with regard to their effects on airway inflammation and mucus production. The levels of HIF-1α and VEGF increased in lung tissue and bronchial fluid of patients with asthma and in the nasal fluid of patients with rhinitis after challenge. CONCLUSIONS: Our results support the notion that HIF is directly involved in the development of AAI. Most importantly, we demonstrate for the first time that HIF-1α is increased after challenge in patients with asthma and rhinitis. Therefore, we propose that HIF may be a potential therapeutic target for asthma and possibly for other inflammatory diseases.
Assuntos
Asma/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Hipersensibilidade Respiratória/fisiopatologia , Rinite/metabolismo , Adolescente , Adulto , Alérgenos/imunologia , Animais , Asma/imunologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Feminino , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Inflamação/imunologia , Inflamação/metabolismo , Pulmão/imunologia , Pulmão/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Ovalbumina/imunologia , Hipersensibilidade Respiratória/imunologia , Hipersensibilidade Respiratória/metabolismo , Rinite/imunologia , Regulação para Cima , Adulto JovemRESUMO
A novel coronavirus named severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a current outbreak of infection termed Coronavirus Disease 2019 (COVID-19) by the World Health Organization (WHO). COVID-19 is currently a global pandemic that may cause close to half a billion deaths around the world. Until now, there is no effective treatment for COVID-19. Quinacrine (Qx) has been used since the 1930s as preventive antimalarial compound. It is a recognized small molecule inhibitor of RNA virus replication, with known anti-prion activity, and identified as a potent Ebola virus inhibitor both in vitro and in vivo. Recently, Qx has showed anti-SARS-CoV-2 activity. Herein, we review the potential mechanisms associated with quinacrine as an antiviral compound.
Assuntos
Antivirais/farmacologia , Tratamento Farmacológico da COVID-19 , Quinacrina/farmacologia , SARS-CoV-2 , Animais , Antivirais/administração & dosagem , Antivirais/efeitos adversos , COVID-19/imunologia , Linhagem Celular , Síndrome da Liberação de Citocina/imunologia , Síndrome da Liberação de Citocina/prevenção & controle , Citocinas/imunologia , Humanos , Camundongos , Quinacrina/administração & dosagem , Quinacrina/efeitos adversos , SARS-CoV-2/efeitos dos fármacos , Replicação Viral/efeitos dos fármacosRESUMO
Cerebral malaria (CM) is a neurological complication derived from the Plasmodium falciparum infection in humans. The mechanisms involved in the disease progression are still not fully understood, but both the sequestration of infected red blood cells (iRBC) and leukocytes and an exacerbated host inflammatory immune response are significant factors. In this study, we investigated the effect of Monocyte Locomotion Inhibitory Factor (MLIF), an anti-inflammatory peptide, in a well-characterized murine model of CM. Our data showed that the administration of MLIF increased the survival and avoided the neurological signs of CM in Plasmodium berghei ANKA (PbA) infected C57BL/6 mice. MLIF administration down-regulated systemic inflammatory mediators such as IFN-γ, TNF-α, IL-6, CXCL2, and CCL2, as well as the in situ expression of TNF-α in the brain. In the same way, MLIF reduced the expression of CD31, CD36, CD54, and CD106 in the cerebral endothelium of infected animals and prevented the sequestration of iRBC and leucocytes in the brain microvasculature. Furthermore, MLIF inhibited the activation of astrocytes and microglia and preserved the integrity of the blood-brain barrier (BBB). In conclusion, our results demonstrated that the administration of MLIF increased survival and conferred neuroprotection by decreasing neuroinflammation in murine CM.
Assuntos
Anti-Inflamatórios/administração & dosagem , Malária Cerebral/prevenção & controle , Fármacos Neuroprotetores/administração & dosagem , Oligopeptídeos/administração & dosagem , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/imunologia , Encéfalo/efeitos dos fármacos , Encéfalo/imunologia , Encéfalo/patologia , Modelos Animais de Doenças , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/imunologia , Feminino , Humanos , Mediadores da Inflamação/antagonistas & inibidores , Mediadores da Inflamação/metabolismo , Malária Cerebral/imunologia , Malária Cerebral/parasitologia , Malária Cerebral/patologia , Camundongos , Microglia/efeitos dos fármacos , Microglia/imunologia , Plasmodium berghei/imunologiaRESUMO
AIMS: Trimethylamine N-oxide (TMAO), choline and betaine serum levels have been associated with metabolic diseases including type 2 diabetes (T2D) and non-alcoholic fatty liver disease (NAFLD). These associations could be mediated by insulin resistance. However, the relationships among these metabolites, insulin resistance and NAFLD have not been thoroughly investigated. Moreover, it has recently been suggested that TMAO could play a role in NAFLD by altering bile acid metabolism. We examined the association between circulating TMAO, choline and betaine levels and NAFLD in obese subjects. METHODS: Serum TMAO, choline, betaine and bile acid levels were measured in 357 Mexican obese patients with different grades of NAFLD as determined by liver histology. Associations of NAFLD with TMAO, choline and betaine levels were tested. Moreover, association of TMAO levels with non-alcoholic steatohepatitis (NASH) was tested separately in patients with and without T2D. RESULTS: TMAO and choline levels were significantly associated with NAFLD histologic features and NASH risk. While increased serum TMAO levels were significantly associated with NASH in patients with T2D, in non-T2D subjects this association lost significance after adjusting for sex, BMI and HOMA2-IR. Moreover, circulating secondary bile acids were associated both with increased TMAO levels and NASH. CONCLUSIONS: In obese patients, circulating TMAO levels were associated with NASH mainly in the presence of T2D. Functional studies are required to evaluate the role of insulin resistance and T2D in this association, both highly prevalent in NASH patients.
Assuntos
Diabetes Mellitus Tipo 2 , Metilaminas/sangue , Hepatopatia Gordurosa não Alcoólica , Adulto , Betaína/sangue , Ácidos e Sais Biliares/sangue , Biomarcadores/sangue , Biópsia , Colina/sangue , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/epidemiologia , Feminino , Humanos , Resistência à Insulina , Fígado/patologia , Masculino , Americanos Mexicanos , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica/complicações , Hepatopatia Gordurosa não Alcoólica/epidemiologia , Obesidade/complicações , Obesidade/epidemiologiaRESUMO
In spite of advances in immunology on mycobacterial infection, there are few studies on the role of anti-microbial peptides in tuberculosis. The cathelin-related anti-microbial peptide (CRAMP) is the only cathelicidin isolated from mice. In this work we investigated the cellular sources and the production kinetics of this molecule during experimental tuberculosis, using two well-characterized models of latent or chronic infection and progressive disease. The lung of non-infected control mice expressed CRAMP at very low levels. In both models of experimental tuberculosis the main cells immunolabelled for CRAMP were bronchial epithelial cells, macrophages and pneumocytes types II and I. After intratracheal infection with a high bacilli dose (H37Rv strain) in Balb/c mice to produce progressive disease, a high CRAMP gene expression was induced showing three peaks: very early after 1 day of infection, at day 21 when the peak of protective immunity in this model is raised, and at day 28 when the progressive phase starts and the immunoelectronmicroscopy study showed intense immunolabelling in the cell wall and cytoplasm of intracellular bacilli, as well as in cytoplasmic vacuoles. Interestingly, at day 60 post-infection, when advanced progressive disease is well established, characterized by high bacillary loads and extensive tissue damage, CRAMP gene expression decreased but strong CRAMP immunostaining was detected in vacuolated macrophages filled with bacilli. Thus, cathelicidin is highly produced during experimental pulmonary tuberculosis from diverse cellular sources and could have significant participation in its pathogenesis.
Assuntos
Peptídeos Catiônicos Antimicrobianos/metabolismo , Tuberculose Latente/metabolismo , Mycobacterium tuberculosis/crescimento & desenvolvimento , Tuberculose Pulmonar/metabolismo , Células Epiteliais Alveolares/metabolismo , Animais , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/genética , Peptídeos Catiônicos Antimicrobianos/farmacologia , Brônquios/metabolismo , Brônquios/patologia , Células Epiteliais/metabolismo , Feminino , Expressão Gênica , Imuno-Histoquímica , Cinética , Tuberculose Latente/genética , Lipopolissacarídeos/metabolismo , Pulmão/metabolismo , Pulmão/microbiologia , Pulmão/ultraestrutura , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Microscopia Imunoeletrônica , Mycobacterium tuberculosis/efeitos dos fármacos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Tuberculose Pulmonar/genética , CatelicidinasRESUMO
To ascertain the in vivo role of mycobacterial lipids phthiocerol dimycocerosates (PDIM) in experimental murine tuberculosis (Tb), airways infection was used to compare the parental virulent clinical isolate MT103 with its mutant fadD26, lacking PDIM. Lungs were assessed as the Tb-target organ and mediastinal lymph nodes as the corresponding lymphoid tissue, in order to quantify: the major T-cell subsets (CD4+/CD8+/gammadelta+) and their activation kinetics, bacillary burden, and in vivo cytotoxicity against inoculated target cells loaded with mycobacterial Ags. After 4 weeks, infection augmented total and activated CD4+ and CD8+ T cells in lungs and nodes mainly with MT103, while gammadelta+ T cells increased earlier in nodes. MT103 bacillary burden was bigger and appeared earlier than the mutant fadD26, especially in the lung than in mediastinal nodes. At day 14 of MT103 infection, there was no cytotoxicity in lungs and nodes; while with fadD26 there was some in the nodes. At day 21 of MT103 infection, important cytotoxicity was detected only in lungs; while with fadD26 both tissues showed important activity. Interestingly, unlike the infection with fadD26, cytotoxicity under MT103 fell considerably in the target organ (lung) from days 21 to 60, the advanced phase. Although upon airways infection both mycobacteria behaved similarly regarding T cell (CD4/CD8/gammadelta) stimulation kinetics; they differed in the magnitude of these responses, in the bacterial load within tissues, and to trigger in vivo cytotoxicity in lungs and regional lymph nodes. This highlights the relevance of certain mycobacterial lipids to modify crucial effector branches of immunity.
Assuntos
Citotoxicidade Imunológica , Lipídeos/fisiologia , Pulmão/imunologia , Linfonodos/imunologia , Linfócitos T/imunologia , Tuberculose/imunologia , Animais , Hipersensibilidade Tardia , Ativação Linfocitária , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Tuberculose/microbiologiaRESUMO
With the hypothesis that genetic variability of Mycobacterium bovis could influence virulence and immunopathology, five M. bovis strains were selected from an epidemiological study in Argentina on the basis of their prevalence in cattle and occurrence in other species. We then determined the virulence and the immunopathology evoked by these strains in a well-characterized mouse model of progressive pulmonary tuberculosis. The reference strain AN5 was used as a control. BALB/c mice infected with this M. bovis reference strain showed 50% survival after 4 months of infection, with moderate bacillary counts in the lung. Two weeks after inoculation, it induced a strong inflammatory response with numerous granulomas and progressive pneumonia. In contrast, strain 04-303, isolated from a wild boar, was the most lethal and its most striking feature was sudden pneumonia with extensive necrosis. Strain 04-302, also isolated from wild boar but with a different spoligotype, induced similar pathology but to a lesser extent. In contrast, strains 534, V2 (both from cattle) and 02-2B (from human) were less virulent, permitting higher survival after 4 months of infection and limited tissue damage. Strain AN5 and the cattle and human isolates induced rapid, high and stable expression of interferon (IFN)-gamma and inducible nitric oxide synthase (iNOS). In contrast, the more virulent strains induced lower expression of IFN-gamma, tumour necrosis factor-alpha and iNOS. Interestingly, these more virulent strains induced very low expression of murine beta defensin 4 (mBD-4); whereas, the control strain AN5 induced progressive expression of this anti-microbial peptide, peaking at day 120. The less virulent strains induced high mBD-4 expression during early infection. Thus, as reported with clinical isolates of M. tuberculosis, M. bovis also showed variable virulence. This variability can be attributed to the induction of a different pattern of immune response.
Assuntos
Mycobacterium bovis/genética , Mycobacterium bovis/imunologia , Tuberculose Pulmonar/imunologia , Animais , Bovinos , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/microbiologia , Ensaio de Unidades Formadoras de Colônias , Progressão da Doença , Variação Genética , Granuloma/microbiologia , Interferon gama/genética , Pulmão/imunologia , Pulmão/microbiologia , Pulmão/patologia , Camundongos , Camundongos Endogâmicos BALB C , Modelos Animais , Óxido Nítrico Sintase Tipo II/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Doenças dos Suínos/imunologia , Doenças dos Suínos/microbiologia , Tuberculose Pulmonar/microbiologia , Tuberculose Pulmonar/patologia , Fator de Necrose Tumoral alfa/genética , Virulência , beta-Defensinas/genéticaRESUMO
BACKGROUND: A hallmark of airway remodelling in asthma is subepithelial fibrosis, but its relation with airway dysfunction is still controversial. OBJECTIVE: To describe airway functional abnormalities and subepithelial remodelling induced by repetitive antigenic challenges. METHODS: Nine inhaled antigenic challenges were applied every 10 days to guinea-pigs sensitized to ovalbumin (OVA). Antigen-induced airway hyperresponsiveness (AI-AHR) to histamine and its immunohistopathological relationship was evaluated at the first, third and ninth OVA challenges. RESULTS: From the first challenge on, OVA induced acute transient bronchoobstruction followed by development of AI-AHR. A progressive rise in baseline Penh (a bronchoobstruction index) and granulocyte airway infiltration was also observed. After the ninth OVA challenge, the amount of extracellular matrix in the subepithelial region (SER) of bronchi and bronchioles was increased. Immunohistochemistry analysis showed that this SER fibrosis was associated to beta1-integrin subunit overexpression, even in acellular areas. Immunoelectronmicroscopy corroborated the location of beta1-integrin in extracellular matrix, essentially in types l and II collagen fibres. Presence of alpha1- and alpha2-integrin subunits in these areas was also corroborated. AI-AHR was correlated with degree of SER increment, cell infiltration, and beta1-integrin expression. CONCLUSION: Our data suggested that beta1-integrin shedding produced by repetitive allergen challenges in guinea-pigs was associated with collagen deposition in SER of bronchi and bronchioles, along with inflammatory cells infiltration and AI-AHR development.
Assuntos
Asma/imunologia , Brônquios/imunologia , Integrina beta1/metabolismo , Administração por Inalação , Animais , Asma/patologia , Brônquios/ultraestrutura , Líquido da Lavagem Broncoalveolar/imunologia , Doença Crônica , Colágeno/imunologia , Colágeno/metabolismo , Modelos Animais de Doenças , Matriz Extracelular/imunologia , Matriz Extracelular/metabolismo , Cobaias , Integrina beta1/imunologia , Masculino , Microscopia Imunoeletrônica , Ovalbumina/imunologiaRESUMO
BACKGROUND: Polymerized-type I collagen (polymerized-collagen) is a down-regulator of inflammation and a tissue regenerator biodrug. The aim of this study was to evaluate its effect in co-cultures of cartilage and synovial tissue from patients with knee osteoarthritis (OA). MATERIALS AND METHODS: Cartilage and synovial tissue from five patients with OA were co-cultured for 7 days in the presence or absence of 1% polymerized-collagen. To determine proteoglycans content, tissues were stained with alcian blue technique. Pro- and anti-inflammatory cytokines [interleukin (IL)-1beta, IL-8, IL-10, IL-12, tumour necrosis factor (TNF)-alpha, and interferon (IFN)-gamma] and tissue inhibitor of metalloproteinase (TIMP)-1 were measured in supernatants by ELISA and results were normalized by total protein concentration. Cartilage oligomeric matrix protein (COMP), type II collagen, TNF-alpha, IL-10 and Ki-67 expression were determined by immunohistochemistry. RESULTS: Polymerized-type I collagen induced an increase of 3- to 6fold cell proliferation (Ki-67), proteoglycans content, and COMP and type II collagen expression, whereas it inhibited IL-1beta and TNF-alpha production. IL-10 levels were up-regulated in treated vs. untreated cultures. No differences were found on IL-8 or TIMP-1 levels in supernatants from polymerized-collagen-treated co-cultures when compared with untreated cultures. IL-12 and IFN-gamma were undetectable. CONCLUSION: The addition of polymerized-type I collagen to cartilage and synovial tissue co-cultures induced up-regulation of chondrocytes proliferation and cartilage extracellular matrix proteins production (COMP, type II collagen and proteoglycans) as well as an anti-inflammatory cytokine (IL-10) and the down-modulation of pro-inflammatory cytokines (IL-1beta and TNF-alpha). It is possible that this mechanism might contribute to induce tissue regeneration and down-regulation of inflammation in OA.