Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
1.
Int J Mol Sci ; 23(19)2022 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-36232806

RESUMO

The SARS-CoV-2 virus infection led to millions of deaths during the COVID-19 pandemic. Hundreds of workers from several other Brazilian cities, as well as from other countries, arrive daily in Macaé to work in the oil supply chain, making this city a putative hotspot for the introduction of new viral lineages. In this study, we performed a genomic survey of SARS-CoV-2 samples from Macaé during the first outbreak of COVID-19, combined with clinical data and a molecular integrative analysis. First, phylogenomic analyses showed a high occurrence of viral introduction events and the establishment of local transmissions in Macaé, including the ingression and spread of the B.1.1.28 lineage in the municipality from June to August 2020. Second, SARS-CoV-2 mutations were identified in patients with distinct levels of COVID-19 severity. Third, molecular interactions of the mutated spike protein from three B.1.1.33 local samples and human ACE2 showed higher interactions than that of the wild-type spike protein from the ancestral virus. Altogether, these results elucidate the SARS-CoV-2 genomic profile in a strategic Brazilian city and further explore the functional aspects of SARS-CoV-2 with a characterization of emerging viral mutations associated with clinical data and the potential targets for drug development against SARS-CoV-2.


Assuntos
COVID-19 , SARS-CoV-2 , Enzima de Conversão de Angiotensina 2 , Brasil/epidemiologia , COVID-19/epidemiologia , Genômica , Humanos , Mutação , Pandemias , Filogenia , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/genética
2.
Parasitology ; 148(8): 934-946, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33827719

RESUMO

Trichomonas vaginalis is a parasite of the human urogenital tract and the causative agent of trichomoniasis, a sexually transmitted disease of worldwide importance. This parasite is usually found as a motile flagellated trophozoite. However, when subjected to stressful microenvironmental conditions, T. vaginalis trophozoites can differentiate into peculiar cyst-like stages, which exhibit notable physiological resistance to unfavourable conditions. Although well documented in morphological and proteomic terms, patterns of gene expression changes involved in the cellular differentiation into cyst-like stages are mostly unknown. The real-time reverse transcription polymerase chain reaction (RT-qPCR) is recognized as a sensitive and accurate method for quantification of gene expression, providing fluorescence-based data that are proportional to the amount of a target RNA. However, the reliability of relative expression studies depends on the validation of suitable reference genes, which RNAs exhibit a minimum of variation between tested conditions. Here, we attempt to determine suitable reference genes to be used as controls of invariant expression during cold-induced in vitro differentiation of T. vaginalis trophozoites into cyst-like forms. Furthermore, we reveal that the mRNA from the meiotic recombinase Dmc1 is upregulated during this process, indicating that cryptic sexual events may take place in cyst-like stages of T. vaginalis.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento/genética , Meiose/genética , Trichomonas vaginalis/crescimento & desenvolvimento , Trichomonas vaginalis/genética , Proteínas de Ciclo Celular/genética , Temperatura Baixa , Proteínas de Ligação a DNA/genética , Humanos , RNA Mensageiro/metabolismo , Valores de Referência , Regulação para Cima
3.
Biochem Biophys Res Commun ; 467(1): 115-20, 2015 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-26408905

RESUMO

The life cycle of the protozoan parasite Trypanosoma cruzi comprises rounds of proliferative cycles and differentiation in distinct host environments. Ras GTPases are molecular switches that play pivotal regulatory functions in cell fate. Rjl is a novel GTPase with unknown function. Herein we show that TcRjl blocks in vivo cell differentiation. The forced expression of TcRjl leads to changes in the overall tyrosine protein phosphorylation profile of parasites. TcRjl expressing parasites sustained DNA synthesis regardless the external stimuli for differentiation. Heterologous expression in the Drosophila melanogaster genetic system strongly suggests a role from TcRjl protein in RTK-dependent pathways and MAPK activation.


Assuntos
Proteínas Monoméricas de Ligação ao GTP/metabolismo , Proteínas de Protozoários/metabolismo , Trypanosoma cruzi/enzimologia , Animais , Animais Geneticamente Modificados , Drosophila melanogaster/enzimologia , Drosophila melanogaster/genética , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Regulação Enzimológica da Expressão Gênica , Genes de Protozoários , Sistema de Sinalização das MAP Quinases , Proteínas Monoméricas de Ligação ao GTP/genética , Fenótipo , Proteínas de Protozoários/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Trypanosoma cruzi/genética , Trypanosoma cruzi/crescimento & desenvolvimento
4.
Insect Biochem Mol Biol ; 172: 104154, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38972513

RESUMO

Chagas disease affects around 8 million people globally, with Latin America bearing approximately 10,000 deaths each year. Combatting the disease relies heavily on vector control methods, necessitating the identification of new targets. Within insect genomes, genes harboring small open reading frames (smORFs - < 100 amino acids) present numerous potential candidates. In our investigation, we elucidate the pivotal role of the archetypal smORF-containing gene, mille-pattes/polished-rice/tarsalless (mlpt/pri/tal), in the post-embryonic development of the kissing bug Rhodnius prolixus. Injection of double-stranded RNA targeting mlpt (dsmlpt) during nymphal stages yields a spectrum of phenotypes hindering post-embryonic growth. Notably, fourth or fifth stage nymphs subjected to dsmlpt do not undergo molting. These dsmlpt nymphs display heightened mRNA levels of JHAMT-like and EPOX-like, enzymes putatively involved in the juvenile hormone (JH) pathway, alongside increased expression of the transcription factor Kr-h1, indicating changes in the hormonal control. Histological examination reveals structural alterations in the hindgut and external cuticle of dsmlpt nymphs compared to control (dsGFP) counterparts. Furthermore, significant changes in the vector's digestive physiology were observed, with elevated hemozoin and glucose levels in the posterior midgut of dsmlpt nymphs. Importantly, dsmlpt nymphs exhibit impaired metacyclogenesis of Trypanosoma cruzi, the causative agent of Chagas disease, underscoring the crucial role of proper gut organization in parasite differentiation. Thus, our findings constitute the first evidence of a smORF-containing gene's regulatory influence on vector physiology, parasitic cycle, and disease transmission.


Assuntos
Proteínas de Insetos , Muda , Ninfa , Rhodnius , Animais , Rhodnius/genética , Rhodnius/fisiologia , Rhodnius/crescimento & desenvolvimento , Ninfa/crescimento & desenvolvimento , Ninfa/genética , Ninfa/fisiologia , Muda/genética , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Hormônios Juvenis/metabolismo , Fases de Leitura Aberta , Digestão
5.
Front Microbiol ; 15: 1386271, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38746751

RESUMO

Introduction: A characteristic of the COVID-19 pandemic has been the sequential emergence and global dissemination of SARS-CoV-2 variants, noted for their enhanced transmission efficiency. These variants with mutations in the Spike glycoprotein (S-glycoprotein), which interacts with ACE2 receptors in human cells is critical for infection, affects the transmissibility of the virus, which is a matter of great concern for public health. Objective: This research analyses the effects these variants on a cohort of vaccinated and naturally infected individuals from the cities of Macaé-RJ, Rio das Ostras-RJ, and Campos dos Goytacazes-RJ, Brazil, from March 2021 to March 2023. Methods: This investigation encompasses the Alpha (B.1.1.7), Gamma (P.1), Delta (B.1.617.2, B.1.671.3), and Omicron (BQ.1, BQ.1.1 sublines, and BF.7) variants, focusing on their genomic surveillance and implications for the disease's epidemiology. The experimental analysis included a control group (vaccinated and uninfected subjects), and an infected group (post-vaccinated subjects). Samples from nasopharyngeal swabs underwent viral detection via RT-qPCR for diagnosis confirmation. RNase H-dependent RT-qPCR (rhAmp-PCR) and third-generation sequencing were used to detect SARS-CoV-2 variants. Anti-S-glycoprotein immunoglobulins were also evaluated for vaccinated infected and noninfected volunteers. Symptoms from infected individuals were compiled in order to reveal patterns of clinical signs associated with viral infection. Results: The study included 289 participants, with infections identified by Gamma (n = 44), Delta (n = 189), and Omicron (n = 56) variants. The prevalent symptoms among the naturally infected participants were cough, fever, sore throat, headache, and runny nose. For Omicron, cognitive symptoms such as memory loss and concentration issues were reported. Interestingly, the infected vaccinated group had higher anti-S-glycoprotein IgM production (n = 28, 0.2833 ± 0.09768 OD) compared to the uninfected vaccinated group (n = 14, 0.1035 ± 0.03625 OD). Conversely, anti-S-glycoprotein IgG production was higher in the control group (n = 12, 1.770 ± 0.1393 OD) than in the infected vaccinated group (n = 26, 1.391 ± 0.1563 OD). Conclusion: This comprehensive study enables monitoring of predominant variants and their correlation with clinical cases, providing valuable insights for public health. Our research group continues to survey circulating variants, contributing to the global understanding of the pandemic.

6.
Biochem Biophys Res Commun ; 419(1): 38-42, 2012 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-22326867

RESUMO

The protozoan parasite Trypanosoma cruzi, the etiological agent of Chagas Disease, undergoes through a complex life cycle where rounds of cell division and differentiation occur initially in the gut of triatominae vectors and, after transmission, inside of infected cells in vertebrate hosts. Members of the Ras superfamily of GTPases are molecular switches which play pivotal regulatory functions in cell growth and differentiation. We have previously described a novel GTPase in T. cruzi, TcRjl, which belongs to the RJL family of Ras-related GTP binding proteins. Here we show that most of TcRjl protein is found bound to GTP nucleotides and may be locked in this stage. In addition, we show that TcRjl is located close to the kinetoplast, in a region corresponding possibly to flagellar pocket of the parasite and the expression of a dominant-negative TcRjl construct (TcRjlS37N) displays a significative growth phenotype in reduced serum medium. Remarkably, overexpression of TcRjl inhibits differentiation of epimastigotes to trypomastigote forms and promotes the accumulation of intermediate differentiation stages. Our data suggest that TcRjl might play a role in the control of the parasite growth and differentiation.


Assuntos
Diferenciação Celular , Proliferação de Células , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Trypanosoma cruzi/crescimento & desenvolvimento , Guanosina Trifosfato/química , Guanosina Trifosfato/metabolismo , Interações Hospedeiro-Parasita , Humanos , Proteínas Monoméricas de Ligação ao GTP/química , Proteínas Monoméricas de Ligação ao GTP/genética , Trypanosoma cruzi/citologia , Trypanosoma cruzi/enzimologia
7.
PeerJ ; 10: e14547, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36540807

RESUMO

Objective: To analyze the long-term dynamics of antibodies against SARS-CoV-2 and understand the impact of age, gender, and viral load on patients' immunological response. Methods: Serum samples were obtained from 231 COVID-19 positive patients from Macaé, in Rio de Janeiro state, in Brazil, from June 2020 until January 2021. The production of IgA, IgM, IgG, and IgE against S glycoprotein was analyzed using the S-UFRJ assay, taking into account the age, gender, and viral load. Results: Analysis of antibody production over 7 months revealed that IgA positivity gradually decreased after the first month. Additionally, the highest percentage of IgM positivity occurred in the first month (97% of patients), and declined after this period, while IgG positivity remained homogeneous for all 7 months. The same analysis for IgE revealed that almost all samples were negative. The comparison of antibody production between genders showed no significant difference. Regarding the age factor and antibody production, patients aged ≥60 years produced almost twice more IgA than younger ones (17-39 years old). Finally, a relationship between viral load and antibody production was observed only for older patients. Conclusions: Our work provides an overview of long-term production of antibodies against SARS-CoV-2, suggesting prolonged production of IgA and IgM antibodies for 3 months and continued IgG production for over 7 months. In addition, it identified a correlation between viral load and IgM titers in the older group and, finally, different IgA production between the age groups.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Feminino , Masculino , Adolescente , Adulto Jovem , Adulto , Anticorpos Antivirais , Imunoglobulina G , Brasil/epidemiologia , Imunoglobulina M , Imunoglobulina A , Imunoglobulina E
8.
Sci Rep ; 11(1): 20121, 2021 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-34635707

RESUMO

The Brazilian strategy to overcome the spread of COVID-19 has been particularly criticized due to the lack of a national coordinating effort and an appropriate testing program. Here, a successful approach to control the spread of COVID-19 transmission is described by the engagement of public (university and governance) and private sectors (hospitals and oil companies) in Macaé, state of Rio de Janeiro, Brazil, a city known as the National Oil Capital. In 2020 between the 17th and 38th epidemiological week, over two percent of the 206,728 citizens were subjected to symptom analysis and RT-qPCR testing by the Federal University of Rio de Janeiro, with positive individuals being notified up to 48 h after swab collection. Geocodification and spatial cluster analysis were used to limit COVID-19 spreading in Macaé. Within the first semester after the outbreak of COVID-19 in Brazil, Macaé recorded 1.8% of fatalities associated with COVID-19 up to the 38th epidemiological week, which was at least five times lower than the state capital (10.6%). Overall, considering the successful experience of this joint effort of private and public engagement in Macaé, our data suggest that the development of a similar strategy countrywise could have contributed to a better control of the COVID-19 spread in Brazil. Quarantine decree by the local administration, comprehensive molecular testing coupled to scientific analysis of COVID-19 spreading, prevented the catastrophic consequences of the pandemic as seen in other populous cities within the state of Rio de Janeiro and elsewhere in Brazil.


Assuntos
Teste de Ácido Nucleico para COVID-19/estatística & dados numéricos , COVID-19/epidemiologia , Pandemias/estatística & dados numéricos , SARS-CoV-2/isolamento & purificação , Adolescente , Adulto , Idoso , Brasil/epidemiologia , COVID-19/diagnóstico , COVID-19/transmissão , COVID-19/virologia , Cidades/epidemiologia , Cidades/estatística & dados numéricos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , RNA Viral/isolamento & purificação , SARS-CoV-2/genética , Adulto Jovem
9.
Biochem Biophys Res Commun ; 345(2): 617-22, 2006 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-16690023

RESUMO

Rho proteins are members of the Ras superfamily of small GTPases. In higher eukaryotes these proteins play pivotal role in cell movement, phagocytosis, intracellular transport, cell-adhesion, and maintenance of cell morphology, mainly through the regulation of actin microfilaments. The GTPase TcRho1 is the only member of the Rho family described in human protozoan parasite Trypanosoma cruzi. We previously demonstrated that TcRho1 is actually required for differentiation of epimastigote to trypomastigote forms during the parasite cell cycle. In the present work, we describe cellular phenotypes induced by TcRho1 heterologous expression in NIH 3T3 fibroblasts. The NIH-3T3 lineages expressing the TcRho1-G15V and TcRho1-Q76L mutants displayed decreased levels of migration compared to the control lineage NIH-3T3 pcDNA3.1, a phenotype probably due to distinct cell-substrate adhesion properties expressed by the mutant cell lines. Accordingly, cell-substrate adhesion assays revealed that the mutant cell lines of NIH-3T3 expressing TcRho1-positive dominants constructions present enhanced substrate-adhesion phenotype. Furthermore, similar experiments with T. cruzi expressing TcRho1 mutants also revealed an enhancement of cell attachment. These results suggest that TcRho1 plays a conserved regulatory role in cell-substrate adhesion in both NIH-3T3 fibroblasts and T. cruzi epimastigotes. Taken together, our data corroborate the notion that TcRho1 may regulate the substrate-adhesion in T. cruzi, a critical step for successful progression of the parasite life cycle.


Assuntos
Adesão Celular/fisiologia , Proteínas de Protozoários/fisiologia , Trypanosoma cruzi/química , Proteínas rho de Ligação ao GTP/fisiologia , Animais , Adesão Celular/genética , Linhagem Celular , Movimento Celular , Fibroblastos/citologia , Fibroblastos/metabolismo , Regulação da Expressão Gênica , Interações Hospedeiro-Parasita , Humanos , Estágios do Ciclo de Vida , Camundongos , Mutação , Células NIH 3T3 , Proteínas Nucleares/química , Proteínas Nucleares/fisiologia , Fenótipo , Proteínas de Protozoários/genética , Fatores de Tempo , Trypanosoma cruzi/citologia , Proteínas rho de Ligação ao GTP/genética
10.
Parasitol Res ; 91(2): 166-70, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12923631

RESUMO

Arfs (ADP-ribosylation factors) are conserved GTP-binding proteins involved in the control of coatomers assembling in budding vesicles in the eukaryotic secretory pathway and during some endocytic events. Here, we describe the gene for an Arf-homologue from the unicellular kinetoplastid parasite Trypanosoma cruzi, named TcArf1. TcArf1 is present in a discrete copy number in the T. cruzi genome and is expressed as a 1-kb transcript in the three main life forms of the parasite. Increased mRNA expression in epimastigotes may correlate with abundant protein biosynthesis and endocytosis in this stage.


Assuntos
Fator 1 de Ribosilação do ADP , Trypanosoma cruzi/metabolismo , Fator 1 de Ribosilação do ADP/química , Fator 1 de Ribosilação do ADP/genética , Fator 1 de Ribosilação do ADP/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Biblioteca Genômica , Dados de Sequência Molecular , Alinhamento de Sequência , Análise de Sequência de DNA , Trypanosoma cruzi/genética , Trypanosoma cruzi/crescimento & desenvolvimento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA