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1.
PLoS Pathog ; 20(6): e1012222, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38838044

ABSTRACT

COVID-19 has affected more than half a billion people worldwide, with more than 6.3 million deaths, but the pathophysiological mechanisms involved in lethal cases and the host determinants that determine the different clinical outcomes are still unclear. In this study, we assessed lung autopsies of 47 COVID-19 patients and examined the inflammatory profiles, viral loads, and inflammasome activation. Additionally, we correlated these factors with the patient's clinical and histopathological conditions. Robust inflammasome activation was detected in the lungs of lethal cases of SARS-CoV-2. Experiments conducted on transgenic mice expressing hACE2 and infected with SARS-CoV-2 showed that Nlrp3-/- mice were protected from disease development and lethality compared to Nlrp3+/+ littermate mice, supporting the involvement of this inflammasome in disease exacerbation. An analysis of gene expression allowed for the classification of COVID-19 patients into two different clusters. Cluster 1 died with higher viral loads and exhibited a reduced inflammatory profile than Cluster 2. Illness time, mechanical ventilation time, pulmonary fibrosis, respiratory functions, histopathological status, thrombosis, viral loads, and inflammasome activation significantly differed between the two clusters. Our data demonstrated two distinct profiles in lethal cases of COVID-19, thus indicating that the balance of viral replication and inflammasome-mediated pulmonary inflammation led to different clinical outcomes. We provide important information to understand clinical variations in severe COVID-19, a process that is critical for decisions between immune-mediated or antiviral-mediated therapies for the treatment of critical cases of COVID-19.


Subject(s)
COVID-19 , Lung , SARS-CoV-2 , Viral Load , Virus Replication , COVID-19/virology , COVID-19/mortality , COVID-19/immunology , COVID-19/pathology , Animals , Humans , Mice , Female , Male , Lung/virology , Lung/pathology , Lung/immunology , Middle Aged , Inflammasomes/immunology , Inflammasomes/metabolism , Aged , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Mice, Transgenic , Pneumonia/virology , Pneumonia/mortality , Pneumonia/immunology , Pneumonia/pathology , Angiotensin-Converting Enzyme 2/metabolism , Angiotensin-Converting Enzyme 2/genetics , Mice, Knockout , Adult
2.
Microb Pathog ; 189: 106577, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38367848

ABSTRACT

Neospora caninum is a protozoan parasite with worldwide incidence, acting as a major cause of reproductive failures in ruminants and neuromuscular symptoms in dogs. Macrophage Migration Inhibitory Factor (MIF) is produced by several cell types and exhibits a central role in immune responses against intracellular pathogens. The present study aimed to comprehend the role of MIF in the relationship between N. caninum and its host. We used in vivo, in vitro and ex vivo experiments in a model of infection based on genetically deficient mice to analyze the infection kinetics and inflammatory markers. MIF production was measured in response to N. caninum during the acute and chronic phases of the infection. While Mif-/- mice survived lethal doses of NcLiv tachyzoites, sublethal infections in these mice showed that parasite burden was controlled in target tissues, alongside with reduced inflammatory infiltrates detected in lung and brain sections. TNF was increased at the initial site of the infection in genetically deficient mice and the MIF-dependent reduction was confirmed in vitro with macrophages and ex vivo with primed spleen cells. In sum, MIF negatively regulated host immunity against N. caninum, favoring disease progression.


Subject(s)
Coccidiosis , Macrophage Migration-Inhibitory Factors , Neospora , Animals , Mice , Dogs , Macrophage Migration-Inhibitory Factors/genetics , Coccidiosis/veterinary
3.
mSphere ; 8(5): e0026323, 2023 10 24.
Article in English | MEDLINE | ID: mdl-37768053

ABSTRACT

Toxoplasma gondii's propensity to infect its host and cause disease is highly dependent on its ability to modulate host cell functions. One of the strategies the parasite uses to accomplish this is via the export of effector proteins from the secretory dense granules. Dense granule (GRA) proteins are known to play roles in nutrient acquisition, host cell cycle manipulation, and immune regulation. Here, we characterize a novel dense granule protein named GRA83, which localizes to the parasitophorous vacuole (PV) in tachyzoites and bradyzoites. Disruption of GRA83 results in increased virulence, weight loss, and parasitemia during the acute infection, as well as a marked increase in the cyst burden during the chronic infection. This increased parasitemia was associated with an accumulation of inflammatory infiltrates in tissues in both acute and chronic infections. Murine macrophages infected with ∆gra83 tachyzoites produced less interleukin-12 (IL-12) in vitro, which was confirmed with reduced IL-12 and interferon-gamma in vivo. This dysregulation of cytokines correlates with reduced nuclear translocation of the p65 subunit of the nuclear factor-κB (NF-κB) complex. While GRA15 similarly regulates NF-κB, infection with ∆gra83/∆gra15 parasites did not further reduce p65 translocation to the host cell nucleus, suggesting these GRAs function in converging pathways. We also used proximity labeling experiments to reveal candidate GRA83 interacting T. gondii-derived partners. Taken together, this work reveals a novel effector that stimulates the innate immune response, enabling the host to limit the parasite burden. Importance Toxoplasma gondii poses a significant public health concern as it is recognized as one of the leading foodborne pathogens in the United States. Infection with the parasite can cause congenital defects in neonates, life-threatening complications in immunosuppressed patients, and ocular disease. Specialized secretory organelles, including the dense granules, play an important role in the parasite's ability to efficiently invade and regulate components of the host's infection response machinery to limit parasite clearance and establish an acute infection. Toxoplasma's ability to avoid early clearance, while also successfully infecting the host long enough to establish a persistent chronic infection, is crucial in allowing for its transmission to a new host. While multiple GRAs directly modulate host signaling pathways, they do so in various ways highlighting the parasite's diverse arsenal of effectors that govern infection. Understanding how parasite-derived effectors harness host functions to evade defenses yet ensure a robust infection is important for understanding the complexity of the pathogen's tightly regulated infection. In this study, we characterize a novel secreted protein named GRA83 that stimulates the host cell's response to limit infection.


Subject(s)
Parasitic Diseases , Toxoplasma , Infant, Newborn , Humans , Animals , Mice , Toxoplasma/metabolism , NF-kappa B/metabolism , Protozoan Proteins/metabolism , Parasitemia , Persistent Infection , Cells, Cultured , Immunity, Innate , Interleukin-12/metabolism
4.
bioRxiv ; 2023 Jun 01.
Article in English | MEDLINE | ID: mdl-37398161

ABSTRACT

Toxoplasma gondii 's propensity to infect its host and cause disease is highly dependent on its ability to modulate host cell functions. One of the strategies the parasite uses to accomplish this is via the export of effector proteins from the secretory dense granules. Dense granule (GRA) proteins are known to play roles in nutrient acquisition, host cell cycle manipulation, and immune regulation. Here, we characterize a novel dense granule protein named GRA83, which localizes to the parasitophorous vacuole in tachyzoites and bradyzoites. Disruption of GRA83 results in increased virulence, weight loss, and parasitemia during the acute infection, as well as a marked increase in the cyst burden during the chronic infection. This increased parasitemia was associated with an accumulation of inflammatory infiltrates in tissues in both the acute and chronic infection. Murine macrophages infected with Δ gra83 tachyzoites produced less interleukin-12 (IL-12) in vitro , which was confirmed with reduced IL-12 and interferon gamma (IFN-γ) in vivo . This dysregulation of cytokines correlates with reduced nuclear translocation of the p65 subunit of the NF-κB complex. While GRA15 similarly regulates NF-κB, infection with Δ gra83/ Δ gra15 parasites did not further reduce p65 translocation to the host cell nucleus, suggesting these GRAs function in converging pathways. We also used proximity labelling experiments to reveal candidate GRA83 interacting T. gondii derived partners. Taken together, this work reveals a novel effector that stimulates the innate immune response, enabling the host to limit parasite burden. Importance: Toxoplasma gondii poses a significant public health concern as it is recognized as one of the leading foodborne pathogens in the United States. Infection with the parasite can cause congenital defects in neonates, life-threatening complications in immunosuppressed patients, and ocular disease. Specialized secretory organelles, including the dense granules, play an important role in the parasite's ability to efficiently invade and regulate components of the host's infection response machinery to limit parasite clearance and establish an acute infection. Toxoplasma' s ability to avoid early clearance, while also successfully infecting the host long enough to establish a persistent chronic infection, is crucial in allowing for its transmission to a new host. While multiple GRAs directly modulate host signaling pathways, they do so in various ways highlighting the parasite's diverse arsenal of effectors that govern infection. Understanding how parasite-derived effectors harness host functions to evade defenses yet ensure a robust infection are important for understanding the complexity of the pathogen's tightly regulated infection. In this study, we characterize a novel secreted protein named GRA83 that stimulates the host cell's response to limit infection.

5.
JMIR Public Health Surveill ; 9: e44647, 2023 05 30.
Article in English | MEDLINE | ID: mdl-37252771

ABSTRACT

BACKGROUND: Multimorbidity is characterized by the co-occurrence of 2 or more chronic diseases and has been a focus of the health care sector and health policy makers due to its severe adverse effects. OBJECTIVE: This paper aims to use the latest 2 decades of national health data in Brazil to analyze the effects of demographic factors and predict the impact of various risk factors on multimorbidity. METHODS: Data analysis methods include descriptive analysis, logistic regression, and nomogram prediction. The study makes use of a set of national cross-sectional data with a sample size of 877,032. The study used data from 1998, 2003, and 2008 from the Brazilian National Household Sample Survey, and from 2013 and 2019 from the Brazilian National Health Survey. We developed a logistic regression model to assess the influence of risk factors on multimorbidity and predict the influence of the key risk factors in the future, based on the prevalence of multimorbidity in Brazil. RESULTS: Overall, females were 1.7 times more likely to experience multimorbidity than males (odds ratio [OR] 1.72, 95% CI 1.69-1.74). The prevalence of multimorbidity among unemployed individuals was 1.5 times that of employed individuals (OR 1.51, 95% CI 1.49-1.53). Multimorbidity prevalence increased significantly with age. People over 60 years of age were about 20 times more likely to have multiple chronic diseases than those between 18 and 29 years of age (OR 19.6, 95% CI 19.15-20.07). The prevalence of multimorbidity in illiterate individuals was 1.2 times that in literate ones (OR 1.26, 95% CI 1.24-1.28). The subjective well-being of seniors without multimorbidity was 15 times that among people with multimorbidity (OR 15.29, 95% CI 14.97-15.63). Adults with multimorbidity were more than 1.5 times more likely to be hospitalized than those without (OR 1.53, 95% CI 1.50-1.56) and 1.9 times more likely need medical care (OR 1.94, 95% CI 1.91-1.97). These patterns were similar in all 5 cohort studies and remained stable for over 21 years. A nomogram model was used to predict multimorbidity prevalence under the influence of various risk factors. The prediction results were consistent with the effects of logistic regression; older age and poorer participant well-being had the strongest correlation with multimorbidity. CONCLUSIONS: Our study shows that multimorbidity prevalence varied little in the past 2 decades but varies widely across social groups. Identifying populations with higher rates of multimorbidity prevalence may improve policy making around multimorbidity prevention and management. The Brazilian government can create public health policies targeting these groups, and provide more medical treatment and health services to support and protect the multimorbidity population.


Subject(s)
Multimorbidity , Adult , Male , Female , Humans , Middle Aged , Aged , Comorbidity , Brazil/epidemiology , Cross-Sectional Studies , Chronic Disease
6.
Cad. saúde colet., (Rio J.) ; 31(1): e31010250, 2023. tab, graf
Article in English | LILACS | ID: biblio-1430143

ABSTRACT

Abstract Background Smoking dependence is a chronic disease and a public health problem. The neurobiology of nicotine addiction can explain smoking behavior. This system has genetic variability that has been associated with vulnerability to dependence. Genetic variability in the neurobiology of smoking can help to understand why individuals exposed to drugs may or may not become addicted. Objective This study aims to address genetic variability in the neurobiology of smoking addiction with a focus on polymorphic genes related to the nicotinic response and the dopaminergic reward pathway. Method This work involved a search of the main scientific research on genetic variability in the neurobiology of smoking and its effects on smoking behavior. One hundred and five studies were selected, most of which highlighted polymorphisms in the genes of nicotinic receptors, dopamine receptors, and nicotine metabolism. Results The majority of studies have focused on genes related to the activation of the dopaminergic reward system by nicotine. Combinations between different polymorphisms were also highlighted, showing that interactions can determine a genetic profile of predisposition to smoking addiction. Additionally, gender and ethnicity were identified as relevant factors. Conclusion Knowledge of the genetic bases involved in the individual response to smoking can enable a better understanding of inter-individual differences in smoking behavior, and contribute to improving the treatment of addiction.


Resumo Introdução A dependência nicotínica é uma doença crônica e um problema de saúde pública. O comportamento tabágico pode ser explicado pela neurobiologia da adição, cujas variações genéticas têm sido associadas à dependência. A variabilidade genética na neurobiologia do tabagismo pode ajudar a entender por que indivíduos expostos a drogas podem ou não se tornar viciados. Objetivo Este estudo tem como objetivo abordar a variabilidade genética na neurobiologia do tabagismo com foco em genes polimórficos relacionados à resposta nicotínica e à via de recompensa dopaminérgica. Método Uma pesquisa foi realizada nas principais bases de dados científicos sobre a variabilidade genética na neurobiologia do tabagismo e seus efeitos no comportamento do tabagismo. 105 estudos foram selecionados, em sua maioria destacando polimorfismos nos genes de receptores nicotínicos, receptores de dopamina e de metabolismo da nicotina. Resultados A maioria dos estudos concentrou-se em genes relacionados à ativação do sistema de recompensa dopaminérgico pela nicotina. Determinadas combinações entre genótipos de diferentes polimorfismos também se destacaram, mostrando que interações gênicas podem determinar um perfil genético de predisposição ao tabagismo. Além disso, gênero e etnia foram identificados como fatores relevantes. Conclusão O conhecimento das bases genéticas envolvidas na resposta individual ao tabagismo pode permitir uma melhor compreensão das diferenças interindividuais no comportamento tabágico e contribuir para melhoria dos tratamentos disponíveis para a dependência.


Subject(s)
Humans , Male , Female , Tobacco Use Disorder , Genetic Variation , Behavior , Genetic Predisposition to Disease , Nicotine , Polymorphism, Genetic , Receptors, Dopamine , Receptors, Nicotinic , Gender Identity
7.
PLoS One ; 17(5): e0268538, 2022.
Article in English | MEDLINE | ID: mdl-35580093

ABSTRACT

The outbreak of COVID-19 has led to there being a worldwide socio-economic crisis, with major impacts on developing countries. Understanding the dynamics of the disease and its driving factors, on a small spatial scale, might support strategies to control infections. This paper explores the impact of the COVID-19 on neighborhoods of Recife, Brazil, for which we examine a set of drivers that combines socio-economic factors and the presence of non-stop services. A three-stage methodology was conducted by conducting a statistical and spatial analysis, including clusters and regression models. COVID-19 data were investigated concerning ten dates between April and July 2020. Hotspots of the most affected regions and their determinant effects were highlighted. We have identified that clusters of confirmed cases were carried from a well-developed neighborhood to socially deprived areas, along with the emergence of hotspots of the case-fatality rate. The influence of age-groups, income, level of education, and the access to essential services on the spread of COVID-19 was also verified. The recognition of variables that influence the spatial spread of the disease becomes vital for pinpointing the most vulnerable areas. Consequently, specific prevention actions can be developed for these places, especially in heterogeneous cities.


Subject(s)
COVID-19 , Brazil/epidemiology , COVID-19/epidemiology , Humans , Pandemics , Residence Characteristics , SARS-CoV-2
8.
Geospat Health ; 17(s1)2022 01 14.
Article in English | MEDLINE | ID: mdl-35147014

ABSTRACT

The paper presents an innovative application to identify areas vulnerable to coronavirus disease 2019 (COVID-19) considering a combination of spatial analysis and a multi-criteria learning approach. We applied this methodology in the state of Pernambuco, Brazil identifying vulnerable areas by considering a set of determinants and risk factors for COVID-19, including demographic, economic and spatial characteristics and the number of human COVID-19 infections. Examining possible patterns over a set number of days taking the number of cases recorded, we arrived at a set of compatible decision rules to explain the relation between risk factors and COVID-19 cases. The results reveal why certain municipalities are critically vulnerable to COVID-19 highlighting locations for which knowledge can be gained about environmental factors.


Subject(s)
COVID-19 , Brazil/epidemiology , Cities , Decision Support Techniques , Humans , SARS-CoV-2
9.
mSphere ; 7(1): e0089621, 2022 02 23.
Article in English | MEDLINE | ID: mdl-35019667

ABSTRACT

The development of molecular genetics has greatly enhanced the study of the biology and pathology associated with parasites of the phylum Apicomplexa. While the molecular tools are highly developed for the apicomplexan Toxoplasma gondii, the closely related parasite Neospora caninum lacks efficient tools for genetic manipulation. To enable efficient homologous recombination in N. caninum, we targeted the Ku heterodimer DNA repair mechanism in the genomic reference strain, Nc-Liverpool (NcLiv), and show that deletion of Ku80 results in a destabilization and loss of its partner Ku70. Disruption of Ku80 generated parasites in which genes are efficiently epitope tagged and only short homology regions are required for gene knockouts. We used this improved strain to target novel nonessential genes encoding dense granule proteins that are unique to N. caninum or conserved in T. gondii. To expand the utility of this strain for essential genes, we developed the auxin-inducible degron system for N. caninum using parasite-specific promoters. As a proof of concept, we knocked down a novel nuclear factor in both N. caninum and T. gondii and showed that it is essential for survival of both parasites. Together, these efficient knockout and knockdown technologies will enable the field to unravel specific gene functions in N. caninum, which is likely to aid in the identification of targets responsible for the phenotypic differences observed between these two closely related apicomplexan parasites. IMPORTANCE Neospora caninum is a parasite with veterinary relevance, inducing severe disease in dogs and reproductive disorders in ruminants, especially cattle, leading to major losses. The close phylogenetic relationship to Toxoplasma gondii and the lack of pathogenicity in humans drives an interest of the scientific community toward using N. caninum as a model to study the pathogenicity of T. gondii. To enable this comparison, it is important to develop efficient molecular tools for N. caninum, to gain accuracy and save time in genetic manipulation protocols. Here, we have developed base strains and protocols using the genomic reference strain of N. caninum to enable efficient knockout and knockdown assays in this model. We demonstrate that these tools are effective in targeting known and previously unexplored genes. Thus, these tools will greatly improve the study of this protozoan, as well as enhance its ability to serve as a model to understand other apicomplexan parasites.


Subject(s)
Neospora , Toxoplasma , Animals , Cattle , Dogs , Gene Knockout Techniques , Neospora/genetics , Phylogeny , Reproduction , Toxoplasma/genetics
10.
Rev. Bras. Cancerol. (Online) ; 68(1)jan./fev./mar. 2022.
Article in Portuguese | LILACS | ID: biblio-1371163

ABSTRACT

A relação entre raça (e etnicidade) e adoecimento no Brasil é bastante sólida e evidente. A cor da pele de um indivíduo influencia significativamente na sua vida, no seu adoecimento e morte. Como exemplo atual sobre o tema, cabe mencionar a relação entre a mortalidade da doença pelo coronavírus 2019 (do inglês, coronavirus disease 2019 - covid-19) e a raça, cuja população de pretos tem uma taxa de mortalidade mais alta do que os brancos


Subject(s)
Humans , Male , Female , Nicotiana , Tobacco Use Disorder , Tobacco Use Disorder/ethnology , Ethnicity , Racism , Tobacco Use , Brazil
11.
JMIR Public Health Surveill ; 7(11): e29693, 2021 11 25.
Article in English | MEDLINE | ID: mdl-34842558

ABSTRACT

BACKGROUND: Multimorbidity is the co-occurrence of two or more chronic diseases. OBJECTIVE: This study, based on self-reported medical diagnosis, aims to investigate the dynamic distribution of multimorbidity across sociodemographic levels and its impacts on health-related issues over 15 years in Brazil using national data. METHODS: Data were analyzed using descriptive statistics, hypothesis tests, and logistic regression. The study sample comprised 679,572 adults (18-59 years of age) and 115,699 elderly people (≥60 years of age) from the two latest cross-sectional, multiple-cohort, national-based studies: the National Sample Household Survey (PNAD) of 1998, 2003, and 2008, and the Brazilian National Health Survey (PNS) of 2013. RESULTS: Overall, the risk of multimorbidity in adults was 1.7 times higher in women (odds ratio [OR] 1.73, 95% CI 1.67-1.79) and 1.3 times higher among people without education (OR 1.34, 95% CI 1.28-1.41). Multiple chronic diseases considerably increased with age in Brazil, and people between 50 and 59 years old were about 12 times more likely to have multimorbidity than adults between 18 and 29 years of age (OR 11.89, 95% CI 11.27-12.55). Seniors with multimorbidity had more than twice the likelihood of receiving health assistance in community services or clinics (OR 2.16, 95% CI 2.02-2.31) and of being hospitalized (OR 2.37, 95% CI 2.21-2.56). The subjective well-being of adults with multimorbidity was often worse than people without multiple chronic diseases (OR=12.85, 95% CI: 12.07-13.68). These patterns were similar across all 4 cohorts analyzed and were relatively stable over 15 years. CONCLUSIONS: Our study shows little variation in the prevalence of the multimorbidity of chronic diseases in Brazil over time, but there are differences in the prevalence of multimorbidity across different social groups. It is hoped that the analysis of multimorbidity from the two latest Brazil national surveys will support policy making on epidemic prevention and management.


Subject(s)
Multimorbidity , Noncommunicable Diseases , Adult , Aged , Brazil/epidemiology , Chronic Disease , Cross-Sectional Studies , Female , Humans , Middle Aged , Noncommunicable Diseases/epidemiology , Prevalence
12.
Front Microbiol ; 12: 659028, 2021.
Article in English | MEDLINE | ID: mdl-33912151

ABSTRACT

Heme oxygenase-1 (HO-1) enzyme exerts beneficial effects at the maternal-fetal interface, especially in trophoblasts, being involved in survival and maturation of these cell phenotypes. Trophoblast cells play essential roles throughout pregnancy, being the gateway for pathogens vertically transmitted, such as Toxoplasma gondii. It was previously shown that HO-1 activity was involved in the control of T. gondii infection in vivo; however, its contribution in trophoblast cells during T. gondii infection, remain undefined. Thus, this study aimed to investigate the influence of HO-1 in T. gondii-infected BeWo and HTR-8/SVneo human trophoblast cells. For this purpose, trophoblast cells were infected and the HO-1 expression was evaluated. T. gondii-infected BeWo cells were treated with hemin or CoPPIX, as inducers of HO-1, or with bilirubin, an end-product of HO-1, and the parasitism was quantified. The involvement of p38 MAPK, a regulator of HO-1, and the cytokine production, were also evaluated. It was found that T. gondii decreased the HO-1 expression in BeWo but not in HTR-8/SVneo cells. When treated with the HO-1 inducers or bilirubin, BeWo cells reduced the parasite proliferation. T. gondii also decreased the p38 MAPK phosphorylation in BeWo cells; on the other hand, HO-1 induction sustained its activation. Finally, the IL-6 production was upregulated by HO-1 induction in T. gondii-infected cells, which was associated with the control of infection.

13.
J Ethnopharmacol ; 273: 114019, 2021 Jun 12.
Article in English | MEDLINE | ID: mdl-33716084

ABSTRACT

ETHNOPHARMACOLOGICAL RELEVANCE: Sulfadiazine and pyrimethamine are the two drugs used as part of the standard therapy for toxoplasmosis, however; they may cause adverse side effects and fail to prevent relapse in many patients, rendering infected individuals at risk of reactivation upon becoming immunocompromised. Extracts from various parts of Annona muricata have been widely used medicinally for the management, control and/or treatment of several human diseases, acting against parasites that cause diseases in humans. AIM OF THE STUDY: This study was performed to investigate the action of the ethanolic extract of A. muricata (EtOHAm) and its fractions in the control of the apicomplexan parasite Toxoplasma gondii in vitro and in vivo, and the effect of EtOHAm on the inflammatory response and lipid profile alteration induced by in vivo T. gondii infection. MATERIALS AND METHODS: The cytotoxicity of EtOHAm and its fractions ethyl acetate (EtOAcAm), n-butanol (BuOHAm), aqueous (H2OAm), hexane (HexAm) and dichloromethane (CH2Cl2Am) was evaluated in NIH/3T3 fibroblasts using the (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The cells were infected with T. gondii, treated with the extracts, and parasite proliferation was analyzed. For the in vivo experiments, C57BL/6 mice were orally infected with T. gondii and, treated with different concentrations of extract fractions that were effective in vitro (EtOHAm, EtOAcAm, HexAm and CH2Cl2Am). Tissue parasitism, histological alterations, systemic cytokine and lipid profile were investigated. RESULTS: EtOHAm, EtOAcAm, BuOHAm, H2OAm presented low cytotoxicity until doses of 200 µg/mL, while HexAm and CH2Cl2Am presented toxicity from doses of 100µg/mL. EtOHAm, HexAm and CH2Cl2Am decreased the parasitism in vitro, presenting a therapeutic index of 2.62, 2.44, and 2.96, respectively. In vivo, EtOHAm, HexAm and CH2Cl2Am improved the survival rate of infected animals, however, only EtOHAm was able to decrease the parasitism in the small intestine and lung. Additionally, EtOHAm decreased the systemic interferon (IFN)-γ and tumor necrosis factor (TNF) systemically in infected mice, and was able to maintain the triglycerides and very-low-density lipoprotein (VLDL) lipid fractions at similar levels to uninfected animals. Although treatment with EtOHAm could not control the inflammation induced by oral infection in the tissues analyzed, it was able to preserve the number of goblet cells in the small intestine. CONCLUSIONS: Ethanolic A. muricata leaf extract could be considered as a good candidate for the development of a complementary/alternative therapy against toxoplasmosis, and also as an anti-inflammatory alternative for decreasing TNF and IFN-γ concentrations and lipid fractions in specific diseases.


Subject(s)
Annona/chemistry , Plant Extracts/therapeutic use , Plant Leaves/chemistry , Toxoplasma/drug effects , Toxoplasmosis, Animal/drug therapy , Animals , Female , Mice , Mice, Inbred C57BL , NIH 3T3 Cells , Phytotherapy , Plant Extracts/administration & dosage , Plant Extracts/chemistry
14.
Front Cell Infect Microbiol ; 11: 789398, 2021.
Article in English | MEDLINE | ID: mdl-35071042

ABSTRACT

Neospora caninum is a protozoan associated with abortions in ruminants and neuromuscular disease in dogs. Classically, the immune response against apicomplexan parasites is characterized by the production of proinflammatory cytokines, such as IL-12, IFN-γ and TNF. TNF is mainly produced during the acute phases of the infections and binds to TNF receptor 1 (CD120a, p55, TNFR1) activating a variety of cells, hence playing an important role in the induction of the inflammatory process against diverse pathogens. Thus, in this study, we aimed to evaluate the role of TNF in cellular and humoral immune responses during N. caninum infection. For this purpose, we used a mouse model of infection based on wildtype (WT) and genetically deficient C57BL/6 mice in TNFR1 (Tnfr1-/-). We observed that Tnfr1-/- mice presented higher mortality associated with inflammatory lesions and increased parasite burden in the brain after the infection with N. caninum tachyzoites. Moreover, Tnfr1-/- mice showed a reduction in nitric oxide (NO) levels in vivo. We also observed that Tnfr1-/- mice showed enhanced serum concentration of antigen-specific IgG2 subclass, while IgG1 production was significantly reduced compared to WT mice, suggesting that TNFR1 is required for regular IgG subclass production and antigen recognition. Based on our results, we conclude that the TNF-TNFR1 complex is crucial for mediating host resistance during the infection by N. caninum.


Subject(s)
Coccidiosis , Neospora , Receptors, Tumor Necrosis Factor, Type I , Tumor Necrosis Factor-alpha/immunology , Animals , Coccidiosis/immunology , Cytokines , Female , Mice , Mice, Inbred C57BL , Mice, Knockout , Pregnancy , Receptors, Tumor Necrosis Factor, Type I/immunology
15.
Rev. bras. ativ. fís. saúde ; 25: 1-7, set. 2020. tab
Article in Portuguese | LILACS | ID: biblio-1148242

ABSTRACT

Os objetivos deste estudo foram estimar a prevalência de inatividade física no lazer e analisar a associação entre as práticas de atividades físicas (AF) pregressas na Educação Física (EF) escolar e fora do contexto escolar, sob a inatividade física no lazer durante o período da pandemia de COVID-19. Estudo transversal em que 1.679 estudantes dos cursos de graduação e pós-graduação da Universidade Federal de Uberlândia responderam um questionário online adaptado do Indicadores de Saúde e Qualidade de Vida em Acadêmicos (ISAQ-A). O período de coleta teve duração de 25 dias, em maio de 2020. A análise da associação empregada foram as Razões de Prevalências (RP), complementadas pelo intervalo de confiança a 95% (IC95%), nas análises brutas e ajustadas. A variável dependente foi relatar não praticar AF no lazer durante a pandemia de COVID-19. As variáveis independentes: prática de AF no período da infância e adolescência, fora da escola e participação nas aulas de Educação Física escolar (participação regular e irregular). As variáveis de controle foram estado de saúde, meios para a prática de AF antes da pandemia e renda. O nível de significância adotado foi de 5%. O não envolvimento em atividades físicas fora do contexto escolar está associado a maiores prevalências de inatividade física no lazer (RP = 1,245; IC95%: 1,087 ­ 1,426). Os achados deste estudo indicam que as AFs realizadas no âmbito do lazer no período da infância e adolescência podem influenciar na manutenção da prática mesmo em situações adversas, como o distanciamento social ocasionado pela pandemia de COVID-19


The objectives of the study were to estimate the prevalence of leisure-time physical inactivity and to analyze the association between past physical activity practices in childhood and adolescence, in the classes of Physical Education and outside the school context, under physical inactivity during leisure-time in COVID-19 pandemic. A cross-sectional study was carried out with college and postgraduate students (n = 1.679) of Federal University of Uberlândia, who answered an adapted online survey "Indicadores de Saúde e Qualidade de Vida em Acadêmicos (ISAQ-A)". The Prevalence Ratio was used, complemented by the 95% confidence interval (95% CI) to estimate association in crude and adjusted analysis. The significance value was 5%. The results revealed that non-involvement in physical activities outside the school context, during childhood and adolescence, is associated with higher prevalence of physical inactivity during leisure (RP: 1,245; IC95%: 1,087 ­ 1,426). The dependent variable was the reported absence of physical activities practice during the covid-19 pandemic. The independent variables were: practice of physical activities during childhood and teenage years during the physical education classes (even if not on a regular basis) and/also out of it. The control variables were health condition, personal income and resources available to enable the practice of physical activities.The findings of this research indicate that the PAs performed in leisure-time during childhood and adolescence can influence the maintenance of the practice even in adverse situations, such as the social distance caused by the pandemic of COVID-19


Subject(s)
Students , Surveys and Questionnaires , Pandemics , Leisure Activities
16.
Article in English | MEDLINE | ID: mdl-32523898

ABSTRACT

Neospora caninum poses as a considerable threat to animal health and generates significant economic impact in livestock production worldwide. Here, we have investigated the mechanism that underlies the participation of the inflammasome complex and Reactive Oxygen Species (ROS) in the regulation of immune responses during N. caninum infection. For that purpose, we used in vitro (bone marrow derived macrophages) and in vivo mouse models of infection. Our results show that NLRP3 and NLRC4 receptors, alongside with ASC and Caspase-1, are required for proper activation of the inflammasome during N. caninum infection. As expected, the engagement of these pathways is crucial for IL-1α, IL-1ß, and IL-18 production, as well as the induction of pyroptosis. Our results also show that N. caninum induces ROS production dependent of the inflammasome assembly, which in its turn also depends on MyD88/NF-κB-induced ROS to maintain its activation and, ultimately, lead to restriction of parasite replication.


Subject(s)
Inflammasomes , Neospora , Animals , Caspase 1 , Interleukin-1beta , Mice , NLR Family, Pyrin Domain-Containing 3 Protein , Reactive Oxygen Species
17.
Sci Rep ; 10(1): 7483, 2020 05 04.
Article in English | MEDLINE | ID: mdl-32366934

ABSTRACT

Neospora caninum is an Apicomplexan parasite related to important losses in livestock, causing abortions and decreased fertility in affected cows. Several chemotherapeutic strategies have been developed for disease control; however, no commercial treatment is available. Among the candidate drugs against neosporosis, phenothiazinium dyes, offer a low cost-efficient approach to parasite control. We report the anti-parasitic effects of the phenothiaziums Methylene Blue (MB), New Methylene Blue (NMB), 1,9-Dimethyl Methylene Blue (DMMB) and Toluidine Blue O (TBO) on N. caninum, using in vitro and in vivo models. The dyes inhibited parasite proliferation at nanomolar concentrations (0.019-1.83 µM) and a synergistic effect was achieved when Methylene Blue was combined with New Methylene Blue (Combination Index = 0.84). Moreover, the phenothiazinium dyes improved parasite clearance when combined with Pyrimethamine (Pyr). Combination of Methylene Blue + 1,9-Dimethyl Methylene Blue demonstrated superior efficacy compared to Pyrimethamine based counterparts in an in vivo model of infection. We also observed that Methylene Blue, New Methylene Blue and 1,9-Dimethyl Methylene Blue increased by 5000% the reactive oxygen species (ROS) levels in N. caninum tachyzoites. Phenothiazinium dyes represent an accessible group of candidates with the potential to compound future formulations for neosporosis control.


Subject(s)
Coccidiosis , Methylene Blue/analogs & derivatives , Neospora/growth & development , Animals , Chlorocebus aethiops , Coccidiosis/drug therapy , Coccidiosis/metabolism , Male , Methylene Blue/pharmacology , Mice , Vero Cells
18.
Vet Parasitol ; 276: 108990, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31775103

ABSTRACT

Neospora caninum infection is an important cause of neuromuscular disease in dogs and abortion in cattle, leading to significant economic losses in beef and dairy industries. The protective immunity against apicomplexan parasites, specifically Toxoplasma gondii and N. caninum, is typically achieved by inducing an IL-12-driven Th1 immune response. IL-12 stimulates IFN-γ production, which activates Inducible Nitric Oxide Synthase (iNOS) and promotes consequent Nitric Oxide (NO) synthesis, classically described as one of the main effector mechanisms for parasite elimination. Here, we aimed to evaluate the role played by iNOS during N. caninum infection. Our results show that N. caninum infection in C57BL/6 wild type (WT) mice induce NO production in vivo and in vitro. In agreement, iNOS deficient mice, as well as WT mice treated with iNOS inhibitor aminoguanidine, succumbed during acute infection with a dose lethal to 50 % of the WT mice, and presented significant increase in parasite load when submitted to sub-lethal infection protocols. Interestingly, the lack of control of parasite proliferation observed in iNOS-/- mice was associated with notable CNS inflammation and increased production of the main systemic proinflammatory cytokines (IL-12, IFN-γ, IL-6, TNF and IL-17A). Taken together, our findings show that iNOS plays an important role in restricting N. caninum replication, while also modulates the inflammatory process induced by the infection.


Subject(s)
Coccidiosis/enzymology , Neospora/immunology , Nitric Oxide Synthase Type II/physiology , Animals , Coccidiosis/parasitology , Coccidiosis/pathology , Interferon-gamma/analysis , Interleukin-12 Subunit p40/analysis , Macrophages/metabolism , Mice , Mice, Inbred C57BL , Nitric Oxide/metabolism , Nitric Oxide Synthase Type II/deficiency
19.
Cad Saude Publica ; 35(7): e00198618, 2019 08 12.
Article in English | MEDLINE | ID: mdl-31411285

ABSTRACT

Benzene is one of the most important substances for assessment, due to its significant use, the environmental contamination resulting from its emission and the effects on human health. It is classified by the International Agency for Research on Cancer (IARC) as a known carcinogen to humans (group 1) and associated with the development of leukemia. In general, the population is exposed to this substance by inhaling contaminated air, which varies according to the location and intensity of its potential sources. The petrochemical industry is one of the most important sources of this compound. The municipality of Duque de Caxias, specifically the Campos Elíseos district, in Rio de Janeiro State, Brazil, houses the Industrial Complex of Campos Elíseos (PICE), a grouping of over 25 industries, which includes the second largest oil refinery in Brazil. Environmental contamination from the PICE has been recognized, but there is a lack of studies concerning its impact on the health of the surrounding population. S-phenylmercapturic acid (S-PMA) concentrations ranging from 0.80 to 8.01µg.g-1 creatinine were observed in the local population, apparently related to hematological changes also observed in exposed population. The quantifiable presence of urinary S-PMA from the benzene metabolism is associated with the fact that 60% of the participants present specific hematological changes, which may be due to the environmental benzene exposure. The allele and genotype frequencies of the CYP2E1 and NQO1 enzymes observed in the study population were similar to those reported in other studies. The presence of the variant allele in the NQO1 genotype may be a risk factor for the observed hematological changes.


Subject(s)
Acetylcysteine/analogs & derivatives , Benzene , Environmental Exposure , Polymorphism, Genetic/genetics , Acetylcysteine/urine , Benzene/adverse effects , Biomarkers/urine , Brazil , Causality , Chemical Industry , Creatinine/urine , Cytochrome P-450 CYP2E1/analysis , Cytochrome P-450 CYP2E1/genetics , Environmental Exposure/adverse effects , Female , Gene Frequency/genetics , Health Surveys/statistics & numerical data , Hematologic Diseases/chemically induced , Humans , Male , NAD(P)H Dehydrogenase (Quinone)/analysis , NAD(P)H Dehydrogenase (Quinone)/genetics , Odds Ratio , Residence Characteristics/statistics & numerical data
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