RESUMO

In the course of infection and intense endotoxemia processes, induction of a catabolic state leading to weight loss is observed in mice and humans. However, the late effects of acute inflammation on energy homeostasis, regulation of body weight and glucose metabolism are yet to be elucidated. Here, we addressed whether serial intense endotoxemia, characterized by an acute phase response and weight loss, could be an aggravating or predisposing factor to weight gain and associated metabolic complications. Male Swiss Webster mice were submitted to 8 consecutive doses of lipopolysaccharide (10 mg/kg LPS), followed by 10 weeks on a high-fat diet (HFD). LPS-treated mice did not show changes in weight when fed standard chow. However, when challenged by a high-fat diet, LPS-treated mice showed greater weight gain, with larger fat depot areas, increased serum leptin and insulin levels and impaired insulin sensitivity when compared to mice on HFD only. Acute endotoxemia caused a long-lasting increase in mRNA expression of inflammatory markers such as TLR-4, CD14 and serum amyloid A (SAA) in the adipose tissue, which may represent the key factors connecting inflammation to increased susceptibility to weight gain and impaired glucose homeostasis. In an independent experimental model, and using publicly available microarray data from adipose tissue from mice infected with Gram-negative bacteria, we performed gene set enrichment analysis and confirmed upregulation of a set of genes responsible for cell proliferation and inflammation, including TLR-4 and SAA. Together, we showed that conditions leading to intense and recurring endotoxemia, such as common childhood bacterial infections, may resound for a long time and aggravate the effects of a western diet. If confirmed in humans, infections should be considered an additional factor contributing to obesity and type 2 diabetes epidemics.

RESUMO

BACKGROUND: The dominant effect of age on COVID-19 mortality obscures the impact of other risk factors. Although the elderly is at a greater risk of severe disease and death due to COVID-19, the interaction of obesity and age was not carefully assessed. This analysis is especially critical for prioritizing groups to receive COVID-19 vaccination. METHODS: Starting with 1,120,767 unvaccinated individuals registered in a Brazilian surveillance system, we selected 313,898 hospitalized COVID-19 patients aged 20 to 89 who had a BMI ≥ 25 kg/m2 and cardiovascular diseases (CVD) or diabetes, as well as individuals with no risk factors associated with severe COVID-19. Patient data were stratified by age, obesity, BMI, and comorbidities, and subsequently, subjected to crude and adjusted odds ratio, hazard ratio, and Kaplan-Meier curves. Disease outcomes were invasive and non-invasive ventilatory support, intensive care unit (ICU) admission, and death. FINDINGS: Obesity alone is a risk factor for in-hospital mortality and is more significant than cardiovascular disease and diabetes. Furthermore, obesity, cardiovascular disease, and diabetes increase the risk of severity and death by COVID-19 more significantly in young adults than in the elderly. When categorizing patients by obesity classes, the severity of obesity was found to be associated with a higher risk of admission to the ICU and death from COVID-19 than the non-obese young adults or elderly population. INTERPRETATION: Our findings highlight the increased risk of severe COVID-19 on the Brazilian obese youth. As SARS-CoV-2 may become a recurrent seasonal infection, future vaccination campaigns against COVID-19 should prioritize obese young individuals. FUNDINGS: This work was supported by the Brazilian National Council for Scientific and Technological Development (grant number 313662/2017-7 and 307356/2017-5; the São Paulo Research Foundation (grant numbers 2018/14933-2); and CAPES.

RESUMO

Kynurenine (KYN), the most abundant metabolite of tryptophan, is classically associated with immune tolerance and tumor immune escape. In the last years, KYN is in the spotlight in other biological processes. Here, we showed that KYN inhibited tyrosinase expression and melanin content in primary human melanocyte and keratinocyte co-cultures. Furthermore, KYN decreased melanosome content in a 3D human skin reconstruction model. In these experiments, we used tyrosine + NH4 Cl to induce pigmentation. We compared the inhibitory effect of KYN on melanogenesis with the already known inhibitory effect promoted by IFN-γ. Since increased KYN production depends on the IFN-γ-inducible enzyme indoleamine-2,3-dioxygenase (IDO), we propose that part of the effect of IFN-γ on melanogenesis involves KYN production. From that, we tested if, during melanogenesis, changes in tryptophan metabolism would occur. For this purpose, we measured tryptophan, KYN and downstream products along with pigmentation. There were no significant changes in Trp metabolism, except for the high consumption of kynurenic acid. Our data identify the skin as a potential target for the action of KYN relevant for skin physiology and pigmentation. The results are discussed concerning the high production of KYN in skin inflammatory disorders and cancer.

Assuntos

Cinurenina , Triptofano , Técnicas de Cocultura , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Queratinócitos/metabolismo , Cinurenina/metabolismo , Melanócitos/metabolismo , Triptofano/farmacologia

RESUMO

Research on melanogenesis, its regulation in health and disease, and the discovery of new molecules with pigmenting and depigmenting activities use different models. Here we standardize a protocol based on previous ones using primary human melanocytes and keratinocytes in co-cultures, in which melanogenesis was induced under mild conditions by the addition of tyrosine plus ammonium chloride (NH4Cl). The expression of MITF, TYR, TYRP1, and Melan-A as well as melanin content were measured. Furthermore, we extended this study to a reconstructed 3D model. Pigmentation was visually observable and melanosomes were identified by Fontana-Masson staining by the addition of tyrosine plus NH4Cl during the stratification phase. The 2D and 3D protocols proposed here circumvent limitations of previous models, using human primary cells and mild conditions for melanogenesis. These protocols offer a viable, robust, simple, and animal-free investigational option for human skin pigmentation studies and screening tests for new compounds that modulate pigmentation.

RESUMO

Indoleamine 2,3-dioxygenase (IDO) is associated with the progression of many types of tumors, including melanoma. However, there is limited information about IDO modulation on tumor cell itself and the effect of BRAF inhibitor (BRAFi) treatment and resistance. Herein, IDO expression was analyzed in different stages of melanoma development and progression linked to BRAFi resistance. IDO expression was increased in primary and metastatic melanomas from patients' biopsies, especially in the immune cells infiltrate. Using a bioinformatics approach, we also identified an increase in the IDO mRNA in the vertical growth and metastatic phases of melanoma. Using in silico analyses, we found that IDO mRNA was increased in BRAFi resistance. In an in vitro model, IDO expression and activity induced by interferon-gamma (IFNγ) in sensitive melanoma cells was decreased by BRAFi treatment. However, cells that became resistant to BRAFi presented random IDO expression levels. Also, we identified that treatment with the IDO inhibitor, 1-methyltryptophan (1-MT), was able to reduce clonogenicity for parental and BRAFi-resistant cells. In conclusion, our results support the hypothesis that the decreased IDO expression in tumor cells is one of the many additional outcomes contributing to the therapeutic effects of BRAFi. Still, the IDO production changeability by the BRAFi-resistant cells reiterates the complexity of the response arising from resistance, making it not possible, at this stage, to associate IDO expression in tumor cells with resistance. On the other hand, the maintenance of 1-MT off-target effect endorses its use as an adjuvant treatment of melanoma that has become BRAFi-resistant.

Assuntos

Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Melanoma/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Neoplasias Cutâneas/tratamento farmacológico , Vemurafenib/farmacologia , Linhagem Celular Tumoral , Bases de Dados Genéticas , Resistencia a Medicamentos Antineoplásicos/genética , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/antagonistas & inibidores , Indolamina-Pirrol 2,3,-Dioxigenase/genética , Melanoma/enzimologia , Melanoma/genética , Terapia de Alvo Molecular , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/metabolismo , Neoplasias Cutâneas/enzimologia , Neoplasias Cutâneas/genética , Triptofano/análogos & derivados , Triptofano/farmacologia

RESUMO

RESUMEN Introducción: el síndrome metabólico se caracteriza por la obesidad central, anomalías metabólicas, dislipidemia e hipertensión arterial y comprende diferentes alteraciones cardiovasculares; así como la presencia de diabetes mellitus. Objetivo: caracterizar los factores de riesgo del síndrome metabólico en adolescentes de San Juan y Martínez durante el año 2018. Métodos: se realizó un estudio observacional, descriptivo y transversal. El universo estuvo constituido por 522 pacientes, se seleccionaron 141 adolescentes mediante un muestreo aleatorio simple. Se realizó la revisión de las historias de salud individual y familiar. Los datos obtenidos fueron procesados mediante SPSS. Resultados: existió predominio del sexo femenino (58,87 %) y color de piel blanca (80,14 %). El 63,1 % presentó antecedentes de hipertensión arterial en familiares de primera línea y el 61 % mostró hábitos alimentarios regulares. El 54,6 % de la muestra se encontró normopeso, el 75,2 % refirió ingerir bebidas alcohólicas y el 88 % eran fumadores. Conclusiones: la presencia de factores de riesgo del síndrome metabólico es cada día mayor en los adolescentes, lo cual trae grandes probabilidades para desarrollarlo en esta etapa de la vida. El diagnóstico precoz permite trabajar sobre ellos y evitar futuras enfermedades y complicaciones asociadas.

---

ABSTRACT Introduction: metabolic syndrome is characterized by central obesity, metabolic abnormalities, dyslipidemia, hypertension and it includes different cardiovascular alterations; as well as the presence of diabetes mellitus. Objective: to characterize the risk factors of the metabolic syndrome in adolescents from San Juan and Martinez municipality during the year 2018. Methods: an observational, descriptive and cross-sectional study was carried out. The target group consisted of 522 patients, 141 of them were chosen through a simple random sampling. Individual and family health histories were reviewed. The data obtained were processed by SPSS. Results: there was a predominance of female sex (58,87 %) and white race (80,14 %). A history of hypertension in first line relatives was found in 63,1 % and 61 % showed average eating habits; 54,6 % of the sample was found to be normal weight, 75,2 % reported drinking alcoholic beverages and 88% were smokers. Conclusions: the presence of risk factors associated with the metabolic syndrome is increasing in adolescents, which brings about great probabilities for its development at this stage of life. Early diagnoses allow working on them and avoid future diseases and associated complications.

RESUMO

Patients infected with the Dengue virus (DENV) often present with a massive generation of DENV-specific antibody-secreting cells (ASCs) in the blood. In some cases, these ASCs represent more than 50% of the circulating B cells, a higher magnitude than those induced by other infections, vaccinations, and plasma cell lymphomas. However, it remains unclear how the DENV infection elicits this colossal response. To address this issue, we utilised an in vitro strategy to induce human PBMCs of healthy individuals incubated with DENV particles (DENV4 TVP/360) to differentiate into ASCs. As controls, PBMCs were incubated with a mitogen cocktail or supernatants of uninfected C6/36 cells (mock). The ASC phenotype and function were increasingly detected in the DENV and mitogen-cultured PBMCs as compared to mock-treated cells. In contrast to the in vivo condition, secreted IgG derived from the PBMC-DENV culture was not DENV-specific. Lower ASC numbers were observed when inactivated viral particles or purified B cells were added to the cultures. The physical contact was essential between B cells and the remaining PBMCs for the DENV-mediated ASC response. Considering the evidence for the activation of the tryptophan metabolism detected in the serum of Dengue patients, we assessed its relevance in the DENV-mediated ASC differentiation. For this, tryptophan and its respective metabolites were quantified in the supernatants of cell cultures through mass spectrophotometry. Tryptophan depletion and kynurenine accumulation were found in the supernatants of PBMC-DENV cultures, which presented enhanced detection of indoleamine 2,3-dioxygenase 1 and 2 transcripts as compared to controls. In PBMC-DENV cultures, tryptophan and kynurenine levels strongly correlated to the respective ASC numbers, while the kynurenine levels were directly proportional to the secreted IgG titers. Contrastingly, PBMCs incubated with Zika or attenuated Yellow Fever viruses showed no correlation between their kynurenine concentrations and ASC numbers. Therefore, our data revealed the existence of distinct pathways for the DENV-mediated ASC differentiation and suggest the involvement of the tryptophan metabolism in this cellular process triggered by flavivirus infections.

Assuntos

Linfócitos B/imunologia , Linfócitos B/virologia , Diferenciação Celular/imunologia , Vírus da Dengue/imunologia , Dengue/metabolismo , Triptofano/metabolismo , Febre Amarela/metabolismo , Vírus da Febre Amarela/imunologia , Infecção por Zika virus/metabolismo , Zika virus/imunologia , Doadores de Sangue , Células Cultivadas , Dengue/imunologia , Dengue/virologia , Humanos , Cinurenina/metabolismo , Febre Amarela/imunologia , Febre Amarela/virologia , Infecção por Zika virus/imunologia , Infecção por Zika virus/virologia

RESUMO

The deleterious health effects of thoracic fractions seem to be more related to the chemical composition of the particles than to their mass concentration. The presence of hazardous materials in PM10 (e.g., heavy metals and metalloids) causes risks to human health. In this study, twelve trace elements (Cd, Cr, Pb, Zn, Cu, Ni, Sn, Ba, Co, As, V, and Sb) in 315 samples of ambient PM10 were analyzed. The samples were collected at an urban background site in a Latin American megacity (Bogota, Colombia) for one year. The concentrations and temporal variabilities of these elements were examined. According to the results, Cu (52 ng/m3), Zn (44 ng/m3), Pb (25 ng/m3), and Ba (20 ng/m3) were the traces with the highest concentrations, particularly during the dry season (January to March), which was characterized by barbecue (BBQ) charcoal combustion and forest fires. In addition, the differences between the results of weekdays and weekends were identified. The determined enrichment factor (EF) indicated that Zn, Pb, Sn, Cu, Cd, and Sb mainly originated from anthropogenic sources. Moreover, a speciation analysis of inorganic Sb (EF > 300) was conducted, which revealed that Sb(V) was the main Sb species in the PM10 samples (>80%). Six causes for the hazardous elements were identified based on the positive matrix factorization (PMF) model: fossil fuel combustion and forest fires (60%), road dust (19%), traffic-related emissions (9%), copper smelting (8%), the iron and steel industry (2%), and an unidentified industrial sector (2%). Furthermore, a health risk assessment of the carcinogenic elements was performed. Accordingly, the cancer risk of inhalation exposure to Co, Ni, As, Cd, Sb(III), and Pb was negligible for children and adults at the sampling site. For adults, the adjusted Cr(VI) level was slightly higher than the minimal acceptable risk level during the study period (1.4 × 10-6).

Assuntos

Material Particulado/análise , Medição de Risco , Poluentes Atmosféricos , Cidades , Colômbia , Poeira , Monitoramento Ambiental , Metais Pesados , Oligoelementos

RESUMO

BACKGROUND: Human papillomavirus (HPV) infection is the central factor for cervical cancer, whereas epithelial immune mechanisms contribute to the progression of HPV infection and its associated lesions. The authors evaluated the expression of indoleamine 2,3-dioxygenase (IDO) and tryptophan 2,3-dioxygenase (TDO) in cervicovaginal samples from women with normal cervical epithelium or with different degrees of squamous intraepithelial lesions (SILs) and cervical cancer. METHODS: IDO expression was analyzed by immunocytochemistry in liquid-based cytology samples from 165 women, of whom 42 had cervical changes subclassified as low-grade SIL (n = 6), high-grade SIL (n = 30), or squamous cell carcinoma (SCC) (n = 6), and 123 had negative Papanicolaou smears. IDO and TDO expression also were analyzed by immunohistochemistry, and HPV and other genital pathogens were evaluated by polymerase chain reaction analysis. RESULTS: Low IDO expression was observed in normal cervical epithelium irrespective of HPV status. Increased numbers of IDO-positive squamous cells and IDO-positive leukocytes were observed in women with SIL or SCC. TDO expression was detected in leukocytes infiltrating the stroma around intraepithelial or invasive cervical lesions. Higher IDO levels were detected in organotypic epithelial cultures established from keratinocytes transduced with the HPV16 E6/E7 oncoproteins. CONCLUSIONS: The upregulation of IDO expression in leukocytes and squamous cells in HPV-associated SIL and SCC suggests that immunosuppressive mechanisms involving tryptophan metabolism may have a role in cervical carcinogenesis. Although previous studies have suggested the role of IDO in HPV pathogenesis, this is the first evidence of TDO involvement in the process. Furthermore, the current data emphasize the role of leukocytes, especially neutrophil-like cells, as an IDO source.

Assuntos

Biomarcadores Tumorais/metabolismo , Carcinoma de Células Escamosas/patologia , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Infecções por Papillomavirus/patologia , Triptofano Oxigenase/metabolismo , Displasia do Colo do Útero/patologia , Neoplasias do Colo do Útero/patologia , Biomarcadores Tumorais/imunologia , Carcinogênese/imunologia , Carcinogênese/patologia , Carcinoma de Células Escamosas/imunologia , Carcinoma de Células Escamosas/virologia , Colo do Útero/imunologia , Colo do Útero/patologia , Colo do Útero/virologia , Feminino , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/imunologia , Pessoa de Meia-Idade , Oligopeptídeos , Teste de Papanicolaou , Papillomaviridae/imunologia , Papillomaviridae/isolamento & purificação , Papillomaviridae/patogenicidade , Infecções por Papillomavirus/imunologia , Infecções por Papillomavirus/virologia , Triptofano Oxigenase/imunologia , Regulação para Cima , Neoplasias do Colo do Útero/imunologia , Neoplasias do Colo do Útero/virologia , Esfregaço Vaginal , Displasia do Colo do Útero/imunologia , Displasia do Colo do Útero/virologia

RESUMO

Road dust has been identified as one of the main sources of outdoor PM10 in Bogota (a Latin American megacity), but there are no studies that have analyzed the physicochemical characteristics and origins of its respirable fraction. A characterization of inorganic compounds (water soluble ions, major and trace elements, organic and elemental carbon) and an analysis of source contributions to the PM10 fraction of road dust were carried out in this study. A total of twenty road dust samples, selected from representative industrial, residential and commercial areas, were swept and resuspended to obtain the thoracic fraction. Size distribution by laser diffraction and individual particle morphology by Scanning Electron Microscopy were also evaluated. The data obtained revealed that the volume (%) of thoracic particles was higher in samples from industrial zones where heavy vehicular traffic, industrial emissions and deteriorated pavements predominated. Crustal elements were the most abundant species, accounting for 49-62% of the thoracic mass, followed by OC (13-29%), water-soluble ions (1.4-3.8%), EC (0.8-1.9%) and trace elements (0.2-0.5%). The Coefficient of Divergence was obtained to identify the spatial variability of the samples. A source apportionment analysis was carried out considering the variability of chemical profiles, enrichment factors and ratios of Fe/Al, K/Al, Ca/Al, Ti/Al, Cu/Sb, Zn/Sb, OC/TC and OC/EC. By means of a PCA analysis, five components were identified, including local soils and pavement erosion (63%), construction and demolition activities (13%), industrial emissions (6%), brake wear (5%) and tailpipe emissions (4%). These components accounted for 91% of the total variance. The results provide data to understand better one of the main sources of PM10 emissions in Bogota, such as road dust. These data will be useful to optimize environmental policies, and they may be used in future studies of human health and air quality modeling.