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1.
Vet Parasitol Reg Stud Reports ; 37: 100815, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36623895

RESUMO

Trypanosoma cruzi is the etiological agent of Chagas disease, a neglected and frequently occurring zoonosis in Central and South American countries. Wild mammals and domestic dogs are the main reservoirs of the parasite in the wild and domestic cycles, respectively. The vectors have a wide variety of food sources that can influence transmission cycles. The aim of this study was to determine the prevalence of T. cruzi infection in donkeys (Equus asininos) and mules (Equus mulus) living in rural areas of the Brazilian semi-arid region. Whole-blood samples from 72 equids (65 donkeys and 7 mules) were analyzed by nested polymerase chain reaction (nested PCR). A total of 51.39% of the samples (37/72) were positive. Phylogenetic analysis identified discrete typing units TcI and TcII, which suggested the possibility that donkeys and mules might be participating in domestic/peridomestic and wild transmission cycles. This was the first report of T. cruzi infection in donkeys and mules in Brazil, with high prevalence of positive animals. This places these animals as potential reservoirs for the parasite and the particular features of these hosts, the presence of vectors and the socioeconomic characteristics of the population under semiarid conditions create interactions that may favor transmission and overlapping T. cruzi infection cycles.


Assuntos
Doença de Chagas , Doenças do Cão , Trypanosoma cruzi , Animais , Cães , Trypanosoma cruzi/genética , Brasil/epidemiologia , Filogenia , Doença de Chagas/epidemiologia , Doença de Chagas/veterinária , Doença de Chagas/parasitologia , Mamíferos/parasitologia
2.
Rural Remote Health ; 23(1): 6796, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36596293

RESUMO

INTRODUCTION: Chagas disease (CD) is a neglected tropical disease that affects 6 to 7 million people worldwide. In South America, CD is a major health problem in several regions, causing more than 12 000 deaths per year. CD is caused by a parasite called Trypanosoma cruzi, mostly transmitted through the contaminated feces of certain species of triatomine bug, commonly known as the 'kissing bug'. CD is endemic in Loja province in the southern region of Ecuador, where triatomines have been found in 68% of communities. Previous promotion of healthy practices in Loja province have included educational programs directed toward youth to affirm cultural and social norms that support health and prevent CD transmission. The present study was designed to evaluate current knowledge related to CD among youth in the three communities of Loja province following previous intervention programs. METHODS: A descriptive, qualitative approach was applied using individual semi-structured interviews with 14 young people (eight females, six males) from three rural communities in Loja province. Interviews assessed knowledge about CD transmission, knowledge about the parasite-vector-disease pathway, and the role of youth in preventing Chagas disease in their communities. RESULTS: Following a thematic analysis of the data, the study results showed there is cursory knowledge of the triatomine insect that can carry the causative parasite for CD. Participants were able to generally talk about the vector, habitat and prevention practices for triatomine infestation. Nevertheless, limited understanding of transmission dynamics in the parasite-vector-disease pathway itself was found. One major finding was that prevention practices were not correctly applied or followed, increasing the risk of exposure in the community. Youth also articulated that CD is stigmatized in their communities, which may be a barrier for prevention efforts. CONCLUSION: Gaps in knowledge about the parasite-vector-disease pathway were identified among youth. Overall, youth responses indicated positive regard for prevention practices and a desire to be involved in prevention programs. Developing educational programs focusing on CD transmission may be needed to improve control and prevention of this parasitic disease. The implications of these findings are discussed for developing effective control programs in the region.


Assuntos
Doença de Chagas , Trypanosoma cruzi , Masculino , Feminino , Humanos , Adolescente , Equador/epidemiologia , População Rural , Doença de Chagas/epidemiologia , Doença de Chagas/prevenção & controle , Doença de Chagas/parasitologia , Trypanosoma cruzi/fisiologia , Ecossistema
3.
J Med Chem ; 66(2): 1221-1238, 2023 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-36607408

RESUMO

Probing multiple proprietary pharmaceutical libraries in parallel via virtual screening allowed rapid expansion of the structure-activity relationship (SAR) around hit compounds with moderate efficacy against Trypanosoma cruzi, the causative agent of Chagas Disease. A potency-improving scaffold hop, followed by elaboration of the SAR via design guided by the output of the phenotypic virtual screening efforts, identified two promising hit compounds 54 and 85, which were profiled further in pharmacokinetic studies and in an in vivo model of T. cruzi infection. Compound 85 demonstrated clear reduction of parasitemia in the in vivo setting, confirming the interest in this series of 2-(pyridin-2-yl)quinazolines as potential anti-trypanosome treatments.


Assuntos
Doença de Chagas , Tripanossomicidas , Trypanosoma cruzi , Humanos , Doença de Chagas/tratamento farmacológico , Quinazolinas/farmacologia , Quinazolinas/uso terapêutico , Relação Estrutura-Atividade , Tripanossomicidas/uso terapêutico , Tripanossomicidas/farmacocinética
4.
J Med Chem ; 66(2): 1522-1542, 2023 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-36626662

RESUMO

Herein, we describe the hit optimization of a novel diarylthioether chemical class found to be active against Trypanosoma cruzi; the parasite responsible for Chagas disease. The hit compound was discovered through a whole-cell phenotypic screen and as such, the mechanism of action for this chemical class is unknown. Our investigations led to clear structure-activity relationships and the discovery of several analogues with high in vitro potency. Furthermore, we observed excellent activity during acute in vivo efficacy studies in mice infected with transgenic T. cruzi. These diarylthioether compounds represent a promising new chemotype for Chagas disease drug discovery and merit further development to increase oral exposure without increasing toxicity.


Assuntos
Doença de Chagas , Tripanossomicidas , Trypanosoma cruzi , Camundongos , Animais , Tripanossomicidas/farmacologia , Tripanossomicidas/uso terapêutico , Tripanossomicidas/química , Doença de Chagas/tratamento farmacológico , Doença de Chagas/parasitologia , Relação Estrutura-Atividade , Descoberta de Drogas
5.
PLoS Negl Trop Dis ; 17(1): e0011019, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36608168

RESUMO

BACKGROUND: There have been significant improvements in Chagas disease therapy and it is now widely accepted that most patients with chronic disease might benefit from therapy. However, there are challenges to monitor drug efficacy and cure for these patients, which are important impediments for current and future therapies. Trypanosoma cruzi-PCR is highly variable while IgG seroconversion takes decades yielding variable results depending on the antigen(s) used for the assay. METHODS AND RESULTS: We used the genomic phage display (gPhage) platform to perform a pairwise comparison of antigens and epitopes recognized by twenty individual patients with chronic Chagas disease before and after treatment with benznidazole. In total, we mapped 54,473 T. cruzi epitopes recognized by IgG from individual patients (N = 20) before benznidazole treatment. After treatment, the number of epitopes recognized by all patients was significantly smaller (21,254), a reduction consistent with a decrease in anti-T. cruzi antibodies. Most of these epitopes represent distinct fragments from the same protein and could, therefore, be grouped into 80 clusters of antigens. After three years of treatment with benznidazole, we observed a 64% reduction in the number of clusters of antigens recognized by patients (59 clusters before versus 21 clusters after treatment). The most abundant antigenic clusters recognized by patients correspond to the surface antigen CA-2 (B13) followed by the microtubule associated antigen, which highlights the value of these epitopes in Chagas disease diagnosis. Most importantly, quantitative pairwise comparison of gPhage data allowed for the prediction of patient response to treatment based on PCR status. PRINCIPAL FINDING: Here, we compiled a list of antigens and epitopes preferentially recognized by Chagas disease patients before and after benznidazole treatment. Next, we observed that gPhage data correlated with patient PCR-status and could, therefore, predict patient response to treatment. Moreover, gPhage results suggest that overall, independent of PCR status, treatment led to a reduction in the presence of T. cruzi-specific antibody levels and the number of antigens and epitopes recognized by these patients. CONCLUSION: The gPhage platform use of unbiased library of antigens, which is different from conventional serological assays that rely on predetermined antigens, is a contribution for the development of novel diagnostic tools for Chagas disease.


Assuntos
Bacteriófagos , Doença de Chagas , Nitroimidazóis , Trypanosoma cruzi , Humanos , Trypanosoma cruzi/genética , Doença de Chagas/diagnóstico , Nitroimidazóis/uso terapêutico , Epitopos , Imunoglobulina G
6.
Vector Borne Zoonotic Dis ; 23(1): 18-28, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36633561

RESUMO

Background: Chagas disease is one of the world's most neglected tropical diseases, infecting over six million people across the Americas. The hemoparasite Trypanosoma cruzi is the etiological agent for the disease, circulating in domestic, peridomestic, and sylvatic transmission cycles that are maintained by triatomine vectors and a diversity of wild and synanthropic hosts. Public health and wildlife management interventions targeting the interruption of T. cruzi transmission rely on an understanding of the dynamics driving the ecology of this zoonotic pathogen. One wildlife host that purportedly plays a role in the transmission of Chagas disease within the southern United States is the striped skunk (Mephitis mephitis), although infection prevalence in this species is poorly understood. Materials and Methods: To this end, we conducted a PCR-based surveillance of T. cruzi in 235 wild skunks, representing 4 species, across 76 counties and 10 ecoregions in Texas, United States, along with an evaluation of risk factors associated with the infection. Results: We recovered an overall T. cruzi prevalence of 17.9% for all mephitid taxa aggregated, ranging between 6.7% for plains spotted skunks (Spilogale putorius interrupta) and 42.9% for western spotted skunks (Spilogale gracilis). We report the first cases of T. cruzi infection in plains spotted and American hog-nosed skunks (Conepatus leuconotus), of important note for conservation medicine since populations of both species are declining within Texas. Although not statistically significant, we also detected trends for juveniles to exhibit greater infection risk than adults and for differential sex biases in T. cruzi prevalence between taxa, which align with variations in species-specific seasonal activity patterns. No geographic or taxonomic risk factors were identified. Conclusion: Our study contributed key data for population viability analyses and epidemiologic models in addition to providing a baseline for future T. cruzi surveillance among skunks and other wildlife species.


Assuntos
Animais Selvagens , Doença de Chagas , Mephitidae , Animais , Animais Selvagens/parasitologia , Doença de Chagas/epidemiologia , Doença de Chagas/veterinária , Doença de Chagas/parasitologia , Prevalência , Texas/epidemiologia , Trypanosoma cruzi
7.
PLoS One ; 18(1): e0280335, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36638112

RESUMO

BACKGROUND: Cardiac complications, including heart failure and arrhythmias, are the leading causes of disability and death in Chagas disease (CD). CD, caused by the Trypanosoma cruzi parasite, afflicts 7 million people in Latin America, and its incidence is increasing in non-endemic countries due to migration. The cardiac involvement is explained by parasite-dependent, immune-mediated myocardial injury, microvascular abnormalities, and ischemia. Current treatment of early CD includes the administration of nifurtimox and benznidazole. However, their efficacy is low in the chronic phase and may induce severe adverse events, forcing therapy to halt. Therefore, finding innovative approaches to treat this life-threatening tropical disease is of utmost importance. Thus, improving the efficacy of the current antichagasic drugs by modifying the inflammatory response would render the current treatment more effective. It has been reported that, in mice, simvastatin decreases cardiac inflammation and endothelial activation, and improves cardiac function, effects that require clinical confirmation. OBJECTIVE: The study aims to analyze whether two doses of Atorvastatin, administered after CD treatment is completed, are safe and more efficacious than the antiparasitic drugs alone in reducing general inflammation and improving endothelial and cardiac functions in a proof-of-concept, placebo-controlled phase II trial. METHODS: 300 subjects will be recruited from four Chilean hospitals with an active Program for the Control of Chagas Disease. 40 or 80 mg/day of atorvastatin or placebo will be administered after completion of the antichagasic therapy. The patients will be followed up for 12 months. Efficacy will be determined by measuring changes in plasma levels of anti-inflammatory and pro-inflammatory cytokines, soluble cell adhesion molecules, BNP, and cTnT. Also, the resting 12-lead ECG and a 2D-echocardiogram will be obtained to evaluate cardiac function. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04984616.


Assuntos
Doença de Chagas , Inibidores de Hidroximetilglutaril-CoA Redutases , Nitroimidazóis , Tripanossomicidas , Trypanosoma cruzi , Atorvastatina/uso terapêutico , Doença de Chagas/tratamento farmacológico , Doença de Chagas/parasitologia , Ensaios Clínicos Fase II como Assunto , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Inflamação/tratamento farmacológico , Inflamação/induzido quimicamente , Estudos Multicêntricos como Assunto , Infecção Persistente , Ensaios Clínicos Controlados Aleatórios como Assunto , Tripanossomicidas/uso terapêutico , Tripanossomicidas/farmacologia , Humanos
8.
Eur J Med Chem ; 248: 115074, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36623331

RESUMO

Chagas disease, after more than a century after its discovery, is still a major public health problem. It is estimated that approximately 10 million people worldwide are infected with T. cruzi. However, the situation is more critical in Latin America and other regions where the disease is endemic. The largest number of cases occurs in Brazil, Argentina, and Mexico as more than 100 million people in these regions are located in areas with a high risk of contamination by the vector. The need for new therapeutic alternatives is urgent, as the available drugs have severe limitations such as low efficacy and high toxicity. From this scenario, in this work, we employed the virtual screening technique using cruzain and BDF2 as key biological targets for the survival of the parasite. Our objective was to identify potential inhibitors of T. cruzi trypomastigotes, which could be considered drug candidates against Chagas disease. For this, we employed different in silico methodologies and the obtained results were corroborated using in vitro biological assays. For the VS studies, a database containing synthetic compounds was simulated at the binding site of cruzain and BDF2. In addition, pharmacophoric models were constructed in the initial phases of VS, as well as other advanced analyses (molecular dynamics simulations, calculations of binding free energy, and ADME prediction) were carried out and the results allowed the selection of potential inhibitors of T. cruzi. Based on the obtained data, 32 different compounds commercially available were subjected to biological tests against the trypomastigote form of T. cruzi. As result, 11 of those compounds displayed significant activity against T. cruzi and can be considered potential candidates for the treatment of Chagas disease.


Assuntos
Doença de Chagas , Tripanossomicidas , Trypanosoma cruzi , Humanos , Doença de Chagas/tratamento farmacológico , Doença de Chagas/parasitologia , Simulação de Dinâmica Molecular , Sítios de Ligação , Domínios Proteicos , Tripanossomicidas/farmacologia , Tripanossomicidas/uso terapêutico , Tripanossomicidas/química
9.
Mikrobiyol Bul ; 57(1): 71-82, 2023 Jan.
Artigo em Turco | MEDLINE | ID: mdl-36636847

RESUMO

Three obligate intracellular protozoan parasite species, namely Trypanosoma cruzi, Leishmania tropica and Toxoplasma gondii, causative agents of Chagas disease, Leishmaniasis and toxoplasmosis, respectively, which are responsible for significant morbidity and mortality and reside in macrophage cells, affect more than half of the world's population in connection with socio-economic and geographical factors and also causes neglected parasitic diseases of increasing importance. This study aimed to evaluate the ex vivo cultivation potential of T.cruzi, L.tropica and T.gondii parasites in J774, Vero and HeLa cells and to reproduce in a short time and in large amounts without losing their virulence properties. Ex vivo experimental models were created by infecting J774, Vero and HeLa cell lines confluently produced in cell culture flasks with T.cruzi, L.tropica and T.gondii parasites. In ex vivo cultivation, one passage was applied for seven days and three times in a row. Cells removed from the surface after each passage were plated on eight-well chamber slides. Giemsa stained slides were prepared and infection rates were evaluated by light microscopic examination. At the end of the study, it was observed that all three cell lines could be infected with T.cruzi, L.tropica and T.gondii parasites, and infection rates increased in all cell lines after consecutive passages. As a result of ex vivo cultivation, the best cell lines from which T.cruzi and L.tropica strains grew, were J774, Vero and HeLa, and HeLa, J774 and Vero cell lines for T.gondii strain, respectively (p<0.05). Trypanosoma cruzi, L.tropica and T.gondii parasites were successfully grown in J774, Vero and HeLa cell lines by ex vivo culture method in a short time and in large amounts without losing their virulence properties. Cell lines with the best ex vivo cultivation potential for T.cruzi and L.tropica parasites were J774, Vero and HeLa, respectively, while HeLa, J774 and Vero for T.gondii. It is thought that the data obtained in this regard will contribute to many studies on the development of vaccines, drugs and new diagnostic kits.


Assuntos
Doença de Chagas , Leishmania tropica , Parasitos , Toxoplasma , Trypanosoma cruzi , Animais , Humanos , Células HeLa
10.
Artigo em Inglês | MEDLINE | ID: mdl-36651468

RESUMO

This study describes the laboratory investigation of two acute Chagas disease outbreaks that occurred in the riverside communities of Marimarituba and Cachoeira do Arua, in the Santarem municipality, Para State, located in the Northern region of Brazil, and occurred in March 2016 and August 2017, respectively. The generation of data regarding the diversity of Trypanosoma cruzi parasites circulating in the Amazon region is key for understanding the emergence and expansion of Chagas disease. This study aimed to identify T. cruzi Discrete Typing Units (DTUs) involved in two outbreaks of acute Chagas disease (ACD) directly from the patient's biological sample. Nested and multiplex PCR targeting the 24Sα (rRNA) and mini-exon genes, respectively, were used to identify T. cruzi DTU in blood samples from patients diagnosed with ACD. The samples with positive cPCR were submitted for analysis for T. cruzi DTUs, which included 13 samples from the patients with ACD by oral transmission and two samples collected from two newborns of two women with ACD, from Marimarituba and Cachoeira do Arua. The samples were classified as T. cruzi TcIV, from Marimarituba's outbreak, and T. cruzi TcI, from Cachoeira do Arua's outbreak. The molecular identification of T. cruzi may increase understanding of the role of this parasite in Chagas disease's emergence within the Amazon region, contributing to the improvement of the management of this important, but also neglected, disease.


Assuntos
Doença de Chagas , Trypanosoma cruzi , Recém-Nascido , Humanos , Feminino , Trypanosoma cruzi/genética , Brasil/epidemiologia , Doença de Chagas/diagnóstico , Doença de Chagas/epidemiologia , Surtos de Doenças , RNA Ribossômico , Genótipo
11.
Mem Inst Oswaldo Cruz ; 117: e220164, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36700581

RESUMO

Chagas disease is an enduring public health issue in many Latin American countries, receiving insufficient investment in research and development. Strategies for disease control and management currently lack efficient pharmaceuticals, commercial diagnostic kits with improved sensitivity, and vaccines. Genetic heterogeneity of Trypanosoma cruzi is a key aspect for novel drug design since pharmacological technologies rely on the degree of conservation of parasite target proteins. Therefore, there is a need to expand the knowledge regarding parasite genetics which, if fulfilled, could leverage Chagas disease research and development, and improve disease control strategies. The growing capacity of whole-genome sequencing technology and its adoption as disease surveillance routine may be key for solving this long-lasting problem.


Assuntos
Doença de Chagas , Trypanosoma cruzi , Humanos , Doença de Chagas/epidemiologia , Trypanosoma cruzi/genética , Genômica , Gerenciamento Clínico
12.
Artigo em Inglês | MEDLINE | ID: mdl-36700605

RESUMO

BACKGROUND: Chagas disease (CD) treatment is commonly associated with a high incidence of adverse effects. It is crucial to study and update these adverse effects to improve the existing knowledge of which drugs to use and to clarify the information presented to patients. METHODS: We analyzed the adverse effects of benznidazole in two cohorts of patients: a large retrospective study and a small prospective study. RESULTS: This large retrospective study described the most and least common adverse effects in our area and characterized our Chagas disease population. This prospective study, along with a close follow-up of the treatment, detected more adverse effects and enhanced the patients' perception of the disease and treatment. CONCLUSIONS: This information is important for preventing non-medical-related withdrawals and for removing baseless fears. Better knowledge of patients could help us provide better care.


Assuntos
Doença de Chagas , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Nitroimidazóis , Tripanossomicidas , Trypanosoma cruzi , Humanos , Estudos Prospectivos , Estudos Retrospectivos , Doença Crônica , Tripanossomicidas/efeitos adversos , Doença de Chagas/tratamento farmacológico , Doença de Chagas/epidemiologia , Nitroimidazóis/efeitos adversos
13.
Parasit Vectors ; 16(1): 26, 2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36691054

RESUMO

BACKGROUND: The study of the ecology of Trypanosoma cruzi is challenging due to its extreme adaptive plasticity, resulting in the parasitism of hundreds of mammal species and dozens of triatomine species. The genetic analysis of blood meal sources (BMS) from the triatomine vector is an accurate and practical approach for gathering information on which wild mammal species participate in a local transmission network. South American coatis, Nasua nasua, act as important reservoir host species of T. cruzi in the Pantanal biome because of their high rate of infection and elevated parasitemia, with the main discrete typing unit (DTU) lineages (TcI and TcII). Moreover, the carnivore coati is the only mammal species to build high arboreal nests for breeding and resting that can be shared by various vertebrate and invertebrate species. Herein, we applied the sensitive and specific methodology of DNA barcoding and molecular cloning to study triatomines found in a coati nest to access the diversity of mammal species that explore this structure, and therefore, may be involved in the parasite transmission network. METHODS: Twenty-three Triatoma sordida were collected in one coati's nest in the subregion of Nhecolândia, Pantanal. The DNA isolated from the gut of insects was subjected to BMS detection by PCR using universal primers that flank variable regions of the cytochrome b (cytb) and 12S rDNA mitochondrial genes from vertebrates. The Trypanosoma spp. diagnosis and DTU genotyping were based on an 18S rDNA molecular marker and also using new cytb gene primers designed in this study. Phylogenetic analyses and chord diagrams were constructed to visualize BMS haplotypes, DTU lineages detected on vectors, and their interconnections. RESULTS: Twenty of 23 triatomines analyzed were PCR-positive (86.95%) showing lineages T. cruzi DTU TcI (n = 2), TcII (n = 6), and a predominance of TcI/TcII (n = 12) mixed infection. Intra-DTU diversity was observed mainly from different TcI haplotypes. Genetic analyses revealed that the southern anteater, Tamandua tetradactyla, was the unique species detected as the BMS of triatomines collected from the coati's nest. At least three different individuals of T. tetradactyla served as BMS of 21/23 bugs studied, as indicated by the cytb and 12S rDNA haplotypes identified. CONCLUSIONS: The identification of multiple BMS, and importantly, different individuals of the same species, was achieved by the methodology applied. The study demonstrated that the southern anteaters can occupy the South American coati's nest, serving as the BMS of T. sordida specimens. Since anteaters have an individualist nonsocial behavior, the three individuals detected as BMS stayed at the coati's nest at different times, which added a temporal character to BMS detection. The TcI and TcII infection, and significantly, a predominance of TcI/TcII mixed infection profile with different TcI and TcII haplotypes was observed, due to the discriminatory capacity of the methodology applied. Tamandua tetradactyla, a host which has been little studied, may have an important role in the T. cruzi transmission in that Pantanal subregion. The data from the present study indicate the sharing of coatis' nests by other mammal species, expanding the possibilities for T. cruzi transmission in the canopy strata. We propose that coatis' nests can act as the true hubs of the T. cruzi transmission web in Pantanal, instead of the coatis themselves, as previously suggested.


Assuntos
Doença de Chagas , Coinfecção , Procyonidae , Triatoma , Trypanosoma cruzi , Humanos , Animais , Trypanosoma cruzi/genética , Vermilingua , Procyonidae/parasitologia , Filogenia , Triatoma/parasitologia , Ecossistema , Mamíferos/parasitologia , Genótipo
14.
Braz. j. biol ; 83: e243910, 2023. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1278525

RESUMO

Abstract Nucleotide excision repair (NER) acts repairing damages in DNA, such as lesions caused by cisplatin. Xeroderma Pigmentosum complementation group C (XPC) protein is involved in recognition of global genome DNA damages during NER (GG-NER) and it has been studied in different organisms due to its importance in other cellular processes. In this work, we studied NER proteins in Trypanosoma cruzi and Trypanosoma evansi, parasites of humans and animals respectively. We performed three-dimensional models of XPC proteins from T. cruzi and T. evansi and observed few structural differences between these proteins. In our tests, insertion of XPC gene from T. evansi (TevXPC) in T. cruzi resulted in slower cell growth under normal conditions. After cisplatin treatment, T. cruzi overexpressing its own XPC gene (TcXPC) was able to recover cell division rates faster than T. cruzi expressing TevXPC gene. Based on these tests, it is suggested that TevXPC (being an exogenous protein in T. cruzi) interferes negatively in cellular processes where TcXPC (the endogenous protein) is involved. This probably occurred due interaction of TevXPC with some endogenous molecules or proteins from T.cruzi but incapacity of interaction with others. This reinforces the importance of correctly XPC functioning within the cell.


Resumo O reparo por excisão de nucleotídeos (NER) atua reparando danos no DNA, como lesões causadas por cisplatina. A proteína Xeroderma Pigmentosum complementation group C (XPC) está envolvida no reconhecimento de danos pela via de reparação global do genoma pelo NER (GG-NER) e tem sido estudada em diferentes organismos devido à sua importância em outros processos celulares. Neste trabalho, estudamos proteínas do NER em Trypanosoma cruzi e Trypanosoma evansi, parasitos de humanos e animais, respectivamente. Modelos tridimensionais das proteínas XPC de T. cruzi e T. evansi foram feitos e observou-se poucas diferenças estruturais entre estas proteínas. Durante testes, a inserção do gene XPC de T. evansi (TevXPC) em T. cruzi resultou em crescimento celular mais lento em condições normais. Após o tratamento com cisplatina, T. cruzi superexpressando seu próprio gene XPC (TcXPC) foi capaz de recuperar as taxas de divisão celular mais rapidamente do que T. cruzi expressando o gene TevXPC. Com base nesses testes, sugere-se que TevXPC (sendo uma proteína exógena em T. cruzi) interfere negativamente nos processos celulares em que TcXPC (a proteína endógena) está envolvida. Isso provavelmente ocorreu pois TevXPC é capaz de interagir com algumas moléculas ou proteínas endógenas de T.cruzi, mas é incapaz de interagir com outras. Isso reforça a importância do correto funcionamento de XPC dentro da célula.


Assuntos
Humanos , Animais , Trypanosoma cruzi/genética , Xeroderma Pigmentoso , Dano ao DNA/genética , Biologia Computacional , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Reparo do DNA/genética
15.
J Comput Aided Mol Des ; 37(2): 75-90, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36494599

RESUMO

Chagas disease, also known as American trypanosomiasis, is a neglected tropical disease caused by the protozoa Trypanosoma cruzi, affecting nearly 7 million people only in the Americas. Polyamines are essential compounds for parasite growth, survival, and differentiation. However, because trypanosomatids are auxotrophic for polyamines, they must be obtained from the host by specific transporters. In this investigation, an ensemble of QSAR classifiers able to identify polyamine analogs with trypanocidal activity was developed. Then, a multi-template homology model of the dimeric polyamine transporter of T. cruzi, TcPAT12, was created with Rosetta, and then refined by enhanced sampling molecular dynamics simulations. Using representative snapshots extracted from the trajectory, a docking model able to discriminate between active and inactive compounds was developed and validated. Both models were applied in a parallel virtual screening campaign to repurpose known drugs as anti-trypanosomal compounds inhibiting polyamine transport in T. cruzi. Montelukast, Quinestrol, Danazol, and Dutasteride were selected for in vitro testing, and all of them inhibited putrescine uptake in biochemical assays, confirming the predictive ability of the computational models. Furthermore, all the confirmed hits proved to inhibit epimastigote proliferation, and Quinestrol and Danazol were able to inhibit, in the low micromolar range, the viability of trypomastigotes and the intracellular growth of amastigotes.


Assuntos
Doença de Chagas , Tripanossomicidas , Trypanosoma cruzi , Humanos , Putrescina/uso terapêutico , Ligantes , Danazol/uso terapêutico , Quinestrol/uso terapêutico , Poliaminas/química , Poliaminas/uso terapêutico , Doença de Chagas/tratamento farmacológico , Doença de Chagas/parasitologia , Proteínas de Membrana Transportadoras/uso terapêutico , Tripanossomicidas/farmacologia , Tripanossomicidas/química
16.
Parasitol Res ; 122(2): 625-634, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36567399

RESUMO

During its life cycle, Trypanosoma cruzi undergoes physiological modifications in order to adapt to insect vector and mammalian host conditions. Metacyclogenesis is essential, as the parasite acquires the ability to infect a variety of mammalian species, including humans, in which pathology is caused. In this work, the transcriptomes of metacyclic trypomastigotes and epimastigotes were analyzed in order to identify differentially expressed genes that may be involved in metacyclogenesis. Toward this end, in vitro induction of metacyclogenesis was performed and metacyclic trypomastigotes obtained. RNA-Seq was performed on triplicate samples of epimastigotes and metacyclic trypomastigotes. Differential gene expression analysis showed 513 genes, of which 221 were upregulated and 292 downregulated in metacyclic trypomastigotes. The analysis showed that these genes are related to biological processes relevant in metacyclogenesis. Within these processes, we found that most of the genes associated with infectivity and gene expression regulation were upregulated in metacyclic trypomastigotes, while genes involved in cell division, DNA replication, differentiation, cytoskeleton, and metabolism were mainly downregulated. The participation of some of these genes in T. cruzi metacyclogenesis is of interest, as they may be used as potential therapeutic targets in the design of new drugs for Chagas disease.


Assuntos
Doença de Chagas , Trypanosoma cruzi , Humanos , Animais , Trypanosoma cruzi/fisiologia , Colômbia , Regulação da Expressão Gênica , Diferenciação Celular , Mamíferos
17.
Eur J Med Chem ; 246: 114926, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36508970

RESUMO

Quinones are attractive pharmacological scaffolds for developing new agents for the treatment of different transmissible and non-transmissible human diseases due to their capacity to alter the cell redox homeostasis. The bioactivity and potential mode of action of 19 p-quinone derivatives fused to different aromatic rings (carbo or heterocycles) and harboring distinct substituents were investigated in infective Trypanosoma brucei brucei. All the compounds, except for a furanequinone (EC50=38 µM), proved to be similarly or even more potent (EC50 = 0.5-5.5 µM) than the clinical drug nifurtimox (EC50 = 5.3 µM). Three furanequinones and one thiazolequinone displayed a higher selectivity than nifurtimox. Two of these selective hits resulted potent inhibitors of T. cruzi proliferation (EC50=0.8-1.1 µM) but proved inactive against Leishmania infantum amastigotes. Most of the p-quinones induced a rapid and marked intracellular oxidation in T. b. brucei. DFT calculations on the oxidized quinone (Q), semiquinone (Q•-) and hydroquinone (QH2) suggest that all quinones have negative ΔG for the formation of Q•-. Qualitative and quantitative structure-activity relationship analyses in two or three dimensions of different electronic and biophysical descriptors of quinones and their corresponding bioactivities (killing potency and oxidative capacity) were performed. Charge distribution over the quinone ring carbons of Q and Q.- and the frontier orbitals energies of SUMO (Q.-) and LUMO (Q) correlate with their oxidative and trypanocidal activity. QSAR analysis also highlighted that both bromine substitution in the p-quinone ring and a bulky phenyl group attached to the furane and thiazole rings (which generates a negative charge due to the π electron system polarized by the nearby heteroatoms) are favorable for activity. By combining experimental and in silico procedures, this study disclosed important information about p-quinones that may help to rationally tune their electronic properties and biological activities.


Assuntos
Doença de Chagas , Tripanossomicidas , Trypanosoma cruzi , Humanos , Nifurtimox/uso terapêutico , Quinonas/farmacologia , Doença de Chagas/tratamento farmacológico , Oxirredução , Simulação por Computador , Tripanossomicidas/farmacologia , Tripanossomicidas/uso terapêutico
18.
Front Cell Infect Microbiol ; 12: 980817, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36467728

RESUMO

Extracellular vesicles (EVs) include a heterogeneous group of particles. Microvesicles, apoptotic bodies and exosomes are the most characterized vesicles. They can be distinguished by their size, morphology, origin and molecular composition. To date, increasing studies demonstrate that EVs mediate intercellular communication. EVs reach considerable interest in the scientific community due to their role in diverse processes including antigen-presentation, stimulation of anti-tumoral immune responses, tolerogenic or inflammatory effects. In pathogens, EV shedding is well described in fungi, bacteria, protozoan and helminths parasites. For Trypanosoma cruzi EV liberation and protein composition was previously described. Dendritic cells (DCs), among other cells, are key players promoting the immune response against pathogens and also maintaining self-tolerance. In previous reports we have demonstrate that T. cruzi downregulates DCs immunogenicity in vitro and in vivo. Here we analyze EVs from the in vitro interaction between blood circulating trypomastigotes (Tp) and bone-marrow-derived DCs. We found that Tp incremented the number and the size of EVs in cultures with DCs. EVs displayed some exosome markers and intracellular RNA. Protein analysis demonstrated that the parasite changes the DC protein-EV profile. We observed that EVs from the interaction of Tp-DCs were easily captured by unstimulated-DCs in comparison with EVs from DCs cultured without the parasite, and also modified the activation status of LPS-stimulated DCs. Noteworthy, we found protection in animals treated with EVs-DCs+Tp and challenged with T. cruzi lethal infection. Our goal is to go deep into the molecular characterization of EVs from the DCs-Tp interaction, in order to identify mediators for therapeutic purposes.


Assuntos
Doença de Chagas , Exossomos , Vesículas Extracelulares , Trypanosoma cruzi , Animais , Comunicação Celular , Doença de Chagas/terapia
19.
Parasit Vectors ; 15(1): 466, 2022 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-36517855

RESUMO

BACKGROUND: Triatoma dimidiata is a vector of the protozoan parasite Trypanosoma cruzi, the etiologic agent of Chagas disease. Phenotypic plasticity allows an organism to adjust its phenotype in response to stimuli or environmental conditions. Understanding the effect of T. cruzi on the phenotypic plasticity of its vectors, known as triatomines, has attracted great interest because of the implications of the parasite-triatomine interactions in the eco-epidemiology and transmission of the etiologic agent of Chagas disease. We investigated if the infection of the vector with T. cruzi may be associated with a change in the antennal phenotype of sylvatic, domestic, and laboratory-reared populations of T. dimidiata. METHODS: The abundance of each type of sensillum (bristles, basiconic, thick- and thin-walled trichoid) on the antennae of T. cruzi-infected and non-infected T. dimidiata reared in the laboratory or collected in sylvatic and domestic ecotopes were measured under light microscopy and compared using Kruskal-Wallis non-parametric tests and permutational multivariate analysis of variance. RESULTS: We found significant differences between sensilla patterns of infected and non-infected insects within sylvatic and domestic populations. Conversely, we found no significant differences between sensilla patterns of infected and non-infected insects within the laboratory-reared population. Besides, for sylvatic and domestic populations, sexual dimorphism tended to be increased in infected insects. CONCLUSION: The differences observed in infected insects could be linked to higher efficiency in the perception of odor molecules related to the search for distant mates and hosts and the flight dispersal in search of new habitats. In addition, these insects could have a positive effect on population dynamics and the transmission of T. cruzi.


Assuntos
Doença de Chagas , Kinetoplastida , Triatoma , Triatominae , Trypanosoma cruzi , Trypanosomatina , Animais , Triatoma/fisiologia , Trypanosoma cruzi/genética , Fenótipo
20.
Artigo em Inglês | MEDLINE | ID: mdl-36542026

RESUMO

BACKGROUND: The emergence of Trypanosoma cruzi infection via oral transmission has a habitual character in its primitive endemic cycle. Recent findings revealed the first death by oral transmission of T. cruzi in the state of Espírito Santo, Brazil, in 2012, which was recorded in the rural area of Guarapari. This study evaluated the characteristics related to the occurrence of natural T. cruzi infection among dogs from the rural areas of Alegre and Iconha, municipalities of Espírito Santo. METHODS: Logistic regression analysis of factors contributing to serological detection of T. cruzi in dogs was performed in environments where Espírito Santo's Department of Health Surveillance had previously notified triatomines positive for Trypanosoma spp. from 2014 to 2017. RESULTS: A total of 36 dogs were analyzed, of which 10 (27.77%) tested positive, one was borderline (2.79%), and 25 tested negative (69.44%) for T. cruzi infection. São Caetano, a district from the Iconha municipality, presented a 25 times greater chance for the detection of positive tests (OR:25; 95% CI; 2.37->100). Dogs with updated mandatory vaccination presented with a lower risk of positive serodiagnosis (OR:0.12; 95% CI: 0.02-0.63). CONCLUSIONS: Our results highlight for the first time the occurrence of natural T. cruzi canine infection, detected in the municipality of Iconha, mainly among dogs with un-updated mandatory vaccines in the district of São Caetano.


Assuntos
Doença de Chagas , Trypanosoma cruzi , Animais , Cães , Brasil/epidemiologia , Insetos Vetores , Doença de Chagas/diagnóstico , Doença de Chagas/epidemiologia , Doença de Chagas/veterinária
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