Navegando por Autor "Leite, Ana Luísa Junqueira"

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Atividade reguladora da via de degradação extracelular de nucleotídeos de adenina na virulência de diferentes cepas e formas evolutivas de Trypanosoma cruzi in vitro e in vivo.
(2020) Leite, Ana Luísa Junqueira; Silva, André Talvani Pedrosa da; Silva, André Talvani Pedrosa da; Roatt, Bruno Mendes; Silva, Eduardo de Almeida Marques da; Bressan, Gustavo Costa; Borges, William de Castro
Populações distintas de Trypanosoma cruzi interagem com células musculares cardíacas de mamíferos, causando diferentes padrões de inflamação e baixa funcionalidade do coração. Durante a infecção pelo T. cruzi, o ATP extracelular é hidrolisado em seu componente monofosfatado (AMP), com base na infectividade, virulência e regulação da resposta inflamatória. T. cruzi realiza essa hidrólise através da ectonucleotidase, TcNTPDase-1. Este estudo teve como objetivo avaliar o papel da via de degradação extracelular de nucleotídeos de adenina em culturas ricas em formas tripomastigotas metacíclicas (CTM) e formas tripomastigotas derivadas de cultura celular (TC) das cepas Colombiana (unidade de tipagem discreta - DTU I), VL-10 (DTU II) e CL (DTU VI) de T. cruzi. Para isso, medimos a atividade da ectonucleotidase no parasito e realizamos a infecção em células J774 infectadas e em camundongos C57BL/6 infectados com parasitos pré-tratados ou não com suramina para avaliar o perfil cardíaco parasitário e inflamatório na fase aguda da infecção. Nossos dados indicaram uma atividade mais alta para hidrólise de ATP no CTM da cepa Colombiana em comparação com as das cepas VL-10 e CL. A TC da cepa CL apresentou maior capacidade de hidrolisar o ATP do que as cepas Colombiana e VL-10. A suramina inibiu a hidrólise de ATP em todas as formas e cepas do parasito estudadas. A infecção em células J774 com parasitos pré-tratados com suramina foi reduzida e aumentou a produção de nitrito in vitro. Estudos in vivo mostraram uma redução do infiltrado inflamatório no tecido cardíaco de animais infectados com TC da cepa Colombiana prétratado com suramina. Em conclusão, a atividade dessa ectonucleotidase nas formas tripomastigotas direciona parte das características biológicas observadas em DTUs distintas e pode induzir patogênese cardíaca durante a infecção por T. cruzi.
Combination therapy with benznidazole and doxycycline shows no additive effect to monotherapy with benznidazole in mice infected with the VL-10 strain of the Trypanosoma cruzi.
(2020) Carneiro, Ana Cláudia Alvarenga; Costa, Guilherme de Paula; Ferreira, Cyntia Silva; Ramos, Isalira Peroba Rezende; Sarandy, Mariáurea Matias; Leite, Ana Luísa Junqueira; Menezes, Ana Paula de Jesus; Silva, Breno de Mello; Nogueira, Katiane de Oliveira Pinto Coelho
Background: Chagas heart disease is the most important clinical manifestation of Trypanosoma cruzi infection. Pharmacological therapies have been proposed aiming to reduce inflammatory response and cardiac damage in infected hosts. In this study, we investigated the use of doxycycline (Dox), in a sub-antimicrobial dose, in monotherapy and in combination with benznidazole (Bz) during the acute phase of infection with the VL-10 strain of T. cruzi, evaluating the therapeutic effect during the acute and chronic phases of the infection. Methods and results: C57BL/6 mice were treated for 20 days with Dox (30 mg/kg), Bz (100 mg/kg), or both drugs in combination starting 9 days after infection. Parasitemia was measured during the acute phase and the animals were monitored for 12 months, after which echocardiography analysis was performed. Blood samples were obtained from euthanized mice for CCL2, CCL5, IL-10 analysis, and cardiac fragments were collected for histopathological evaluation. Dox treatment did not ameliorate parasitological/inflammatory parameters but reduced the cardiac collagen neoformation (CN) in 35%. In contrast, Bz administration reduced parasitemia, plasma levels of CCL2 and CCL5, and cardiac infiltration during acute infection, and reduced the level of IL-10 and CN (95%) at 12 months. Dox was unable to improve ejection fraction, while Bz treatment ameliorated the ejection fraction. No additive effect was observed in combination therapy. Conclusion: Dox monotherapy is not effective in the acute or chronic phases of experimental cardiomyopathy induced by the VL-10 strain of T. cruzi. Furthermore, combination therapy with Dox does not potentiate the effects of Bz monotherapy.
Ectonucleotidases from trypomastigotes from different sources and various genetic backgrounds of Trypanosoma cruzi potentiate their infectivity and host inflammation.
(2020) Leite, Ana Luísa Junqueira; Oliveira, Daniela Silva de; Mota, Ludmilla Walter Reis; Carvalho, Luana Cristina Faria; Zimmermann, Fernanda Francine; Paiva, Nívia Carolina Nogueira de; Vieira, Paula Melo de Abreu; Lana, Marta de; Afonso, Luís Carlos Crocco; Silva, André Talvani Pedrosa da
Distinct populations of Trypanosoma cruzi interact with mammalian cardiac muscle cells causing different inflammation patterns and low heart functionality. During T. cruzi infection, the extracellular ATP is hydrolyzed to tri- and/or diphosphate nucleotides, based on the infectivity, virulence, and regulation of the inflammatory response. T. cruzi carries out this hydrolysis through the T. cruzi ectonucleotidase, NTPDase-1 (TcNTPDase-1). This study aimed to evaluate the role of TcNTPDase-1 in culture rich in metacyclic trypomastigote forms (MT) and cell culture-derived trypomastigote forms (CT) from Colombiana (discrete typing unit - DTU I), VL-10 (DTU II), and CL (DTU VI) strains of T. cruzi. For this, we measured TcNTPDase-1 activity in suramin-treated and untreated parasites and infected J774 cells and C57BL/6 mice with suramin pre-treated parasites to assess parasitic and inflammatory cardiac profile in the acute phase of infection. Our data indicated a higher TcNTPDase-1 activity for ATP in culture rich in metacyclic trypomastigote forms from Colombiana strain in comparison to those from VL-10 and CL strains. The cell culture-derived trypomastigote forms from CL strain presented higher capacity to hydrolyze ATP than those from Colombiana and VL-10 strains. Suramin inhibited ATP hydrolysis in all studied parasite forms and strains. Suramin pre-treated parasites reduced J774 cell infection and increased nitrite production in vitro. In vivo studies showed a reduction of inflammatory infiltrate in the cardiac tissues of animals infected with cell culture-derived trypomastigote forms from suramin pre-treated Colombiana strain. In conclusion, TcNTPDase-1 activity in trypomastigotes forms drives part of the biological characteristics observed in distinct DTUs and may induce cardiac pathogenesis during T. cruzi infection.
Enalapril in combination with benznidazole reduces cardiac inflammation and creatine kinases in mice chronically infected with Trypanosoma cruzi.
(2015) Penitente, Arlete Rita; Leite, Ana Luísa Junqueira; Costa, Guilherme de Paula; Bajracharya, Deena Shrestha; Horta, Aline Luciano; Natali, Antônio José; Neves, Clóvis Andrade
The protozoan Trypanosoma cruzi triggers an inflammatory process in mammalian heart causing events such as fibrosis, changes in the architecture and functionality in this organ. Enalapril, an angiotensin II-converting enzyme inhibitor, is a drug prescribed to ameliorate this heart dysfunction, and appears to exert a potential role in immune system regulation. Our aim was to evaluate the chronic cardiac inflammatory parameters after therapeutic treatment with enalapril and benznidazole in C57BL/6 mice infected with the VL-10 strain of T. cruzi. After infection, animals were treated with oral doses of enalapril (25 mg/kg), benznidazole (100 mg/kg), or both during 30 days. Morphometric parameters and levels of chemokines (CCL2, CCL5), IL-10, creatine kinases (CKs), and C-reactive protein were evaluated in the heart and serum at the 120th day of infection. Enalapril alone or in combination with benznidazole did not change the number of circulating parasites, but reduced cardiac leukocyte recruitment and total collagen in the cardiac tissue. Interestingly, the combination therapy (enalapril/benznidazole) also reduced the levels of chemokines, CK and CK-MB, and C-reactive proteins in chronic phase. In conclusion, during the chronic experimental T. cruzi infection, the combination therapy using enalapril plus benznidazole potentiated their immunomodulatory effects, resulting in a low production of biomarkers of cardiac lesions
Expression and production of cardiac angiogenic mediators depend on the Trypanosoma cruzi-genetic population in experimental C57BL/6 mice infection.
(2017) Bajracharya, Deena Shrestha; Bajracharya, Bijay; Costa, Guilherme de Paula; Salles, Beatriz Cristina Silveira; Leite, Ana Luísa Junqueira; Menezes, Ana Paula de Jesus; Souza, Débora Maria Soares de; Oliveira, Laser Antônio Machado de; Silva, André Talvani Pedrosa da
Mammalian cardiac cells are important targets to the protozoan Trypanosoma cruzi. The inflammatory reaction in the host aims at eliminating this parasite, can lead to cell destruction, fibrosis and hypoxia. Local hypoxia iswelldefined stimulus to the production of angiogenesis mediators. Assuming that different genetic T. cruzi populations induce distinct inflammation and disease patterns, the current study aims to investigate whether the production of inflammatory and angiogenic mediators is a parasite strain-dependent condition. C57BL/6 mice were infectedwith the Y and Colombian strains of T. cruzi and euthanized at the 12th and 32nd days, respectively. The blood and heart tissue were processed in immune assays and/or qPCR (TNF, IL-17, IL-10, CCL2, CCL3, CCL5, CCR2, CCR5 and angiogenic factors VEGF, Ang-1, Ang-2) and in histological assays. The T. cruzi increased the inflammatory and angiogenicmediators in the infectedmicewhen theywere compared to non-infected animals.However, the Colombian strain has led to higher (i) leukocyte infiltration, (ii) cardiac TNF and CCL5 production/expression, (iii) cardiac tissue parasitism, and to higher (iv) ratio between heart/body weights. On the other hand, the Colombian strain has caused lower production and expression VEGF, Ang-1 and Ang-2, when it was compared to the Y strain of the parasite. The present study highlights that the T. cruzi-genetic population defines the pattern of angiogenic/inflammatory mediators in the heart tissue, and that itmay contribute to themagnitude of the cardiac pathogenesis. Besides, such assumption opens windows to the understanding of the angiogenic mediator's role in association with the experimental T. cruzi infection.
A high-fat diet exacerbates the course of experimental Trypanosoma cruzi infection that can be mitigated by treatment with Simvastatin.
(2020) Souza, Débora Maria Soares de; Costa, Guilherme de Paula; Leite, Ana Luísa Junqueira; Oliveira, Daniela Silva de; Pinto, Kelerson Mauro de Castro; Farias, Sílvia Elvira Barros; Simões, Natália Figueira; Paiva, Nívia Carolina Nogueira de; Vieira, Paula Melo de Abreu; Silva, Camilo Adalton Mariano da; Figueiredo, Vivian Paulino; Menezes, Ana Paula de Jesus; Silva, André Talvani Pedrosa da
The protozoan Trypanosoma cruzi is responsible for triggering a damage immune response in the host cardiovascular system. This parasite has a high affinity for host lipoproteins and uses the low-density lipoprotein (LDL) receptor for its invasion. Assuming that the presence of LDL cholesterol in tissues could facilitate T. cruzi proliferation, dietary composition may affect the parasite-host relationship. Therefore, the aim of this study was to evaluate myocarditis in T. cruzi-infected C57BL/6 mice—acute phase—fed a high-fat diet and treated with simvastatin, a lipid-lowering medication. Animals (n = 10) were infected with 5 × 103 cells of the VL-10 strain of T. cruzi and treated or untreated daily with 20 mg/kg simvastatin, starting 24 h after infection and fed with a normolipidic or high-fat diet. Also, uninfected mice, treated or not with simvastatin and fed with normolipidic or high-fat diet, were evaluated as control groups. Analyses to measure the production of chemokine (C-C motif) ligand 2 (CCL2), interferon- (IFN-) γ, interleukin- (IL-) 10, and tumor necrosis factor (TNF); total hepatic lipid dosage; cholesterol; and fractions, as well as histopathological analysis, were performed on day 30 using cardiac and fat tissues. Our results showed that the high-fat diet increased (i) parasite replication, (ii) fat accumulation in the liver, (iii) total cholesterol and LDL levels, and (iv) the host inflammatory state through the production of the cytokine TNF. However, simvastatin only reduced the production of CCL2 but not that of other inflammatory mediators or biochemical parameters. Together, our data suggest that the high-fat diet may have worsened the biochemical parameters of the uninfected and T. cruzi-infected animals, as well as favored the survival of circulating parasites.
Insights into IL-33 on inflammatory response during in vitro infection by Trypanosoma cruzi.
(2022) Oliveira, Daniela Silva de; Leite, Ana Luísa Junqueira; Pedrosa, Tamiles Caroline Fernandes; Mota, Ludmilla Walter Reis; Costa, Guilherme de Paula; Souza, Débora Maria Soares de; Perucci, Luiza Oliveira; Silva, André Talvani Pedrosa da
Inflammatory and regulatory cytokines play an important role in the immunopathogenesis of Trypanosoma cruzi infection. Interleukin (IL)-33 is a member of the IL-1 superfamily of cytokines whose expression/production is upregulated following pro-inflammatory stimulation to alert the immune system in response to tissue stress or damage. The aim of this study was to evaluate the inflammatory profile induced in cultured J774 cells stimulated or not with IL-33 (10 ng/mL), with live parasites (1 × 106 metacyclic trypomastigote forms) and/or total antigen, TcAg (100 μg/mL) and with both, IL-33 and TcAg/T. cruzi. The cultures were evaluated at 24 h and 48 h after addition of the stimuli. For this, the supernatants were collected for the measurement of TNF, IL-17, CCL2, and IL-10 by ELISA and of nitrite by the Griess method. TNF, IL-17, and CCL2 concentrations were elevated in the presence of TcAg or live T. cruzi parasites at 24 h, and the addition of IL-33 potentiated these effects at 48 h. In addition, the T. cruzi-amastigote forms reduced in those infected J774 cells stimulated with IL-33 at 48 h. In conclusion, the IL-33 elevated the production of the TNF, IL-17, and CCL2 in cultured J774 cells stimulated with T. cruzi and/or its antigen and reduced the intracellular parasites, providing impetus to new investigations on its potential actions on the parasite-induced inflammation.
New insights into blue light phototherapy in experimental Trypanosoma cruzi infection.
(2021) Ivanova, Natalia; Leite, Ana Luísa Junqueira; Vieira, Marcel Barbosa; Silva, Otto Henrique Cezar e; Mota, Ludmilla Walter Reis; Costa, Guilherme de Paula; Azevedo, Cristiano Schetini de; Auharek, Sarah Alves; Novaes, Romulo Dias; Pinto, Kelerson Mauro de Castro; Bianchi, Rodrigo Fernando; Silva, André Talvani Pedrosa da
The search for an effective etiologic treatment to eliminate Trypanosoma cruzi, the causative agent of Chagas disease, has continued for decades and yielded controversial results. In the 1970s, nifurtimox and benznidazole were introduced for clinical assessment, but factors such as parasite resistance, high cellular toxicity, and efficacy in acute and chronic phases of the infection have been debated even today. This study proposes an innovative strategy to support the controlling of the T. cruzi using blue light phototherapy or blue light-emitting diode (LED) intervention. In in vitro assays, axenic cultures of Y and CL strains of T. cruzi were exposed to 460 nm and 40 μW/cm2 of blue light for 5 days (6 h/day), and parasite replication was evaluated daily. For in vivo experiments, C57BL6 mice were infected with the Y strain of T. cruzi and exposed to 460 nm and 7 μW/cm2 of blue light for 9 days (12 h/day). Parasite count in the blood and cardiac tissue was determined, and plasma interleukin (IL-6), tumoral necrosis factor (TNF), chemokine ligand 2 (CCL2), and IL-10 levels and the morphometry of the cardiac tissue were evaluated. Blue light induced a 50% reduction in T. cruzi (epimastigote forms) replication in vitro after 5 days of exposure. This blue light-mediated parasite control was also observed by the T. cruzi reduction in the blood (trypomastigote forms) and in the cardiac tissue (parasite DNA and amastigote nests) of infected mice. Phototherapy reduced plasma IL-6, TNF and IL-10, but not CCL2, levels in infected animals. This non-chemical therapy reduced the volume density of the heart stroma in the cardiac connective tissue but did not ameliorate the mouse myocarditis, maintaining a predominance of pericellular and perivascular mononuclear inflammatory infiltration with an increase in polymorphonuclear cells. Together, these data highlight, for the first time, the use of blue light therapy to control circulating and tissue forms of T. cruzi. Further investigation would demonstrate the application of this promising and potential complementary strategy for the treatment of Chagas disease.
Potential role of Carvedilol in the cardiac immune response induced by experimental infection with Trypanosoma cruzi.
(2017) Horta, Aline Luciano; Leite, Ana Luísa Junqueira; Costa, Guilherme de Paula; Figueiredo, Vivian Paulino; Silva, André Talvani Pedrosa da
Trypanosoma cruzi causes a cardiac infection characterized by an inflammatory imbalance that could become the inciting factor of the illness. To this end, we evaluated the role of carvedilol, a beta-blocker with potential immunomodulatory properties, on the immune response in C57BL/6 mice infected with VL-10 strain of T. cruzi in the acute phase. Animals (𝑛 = 40) were grouped: (i) not infected, (ii) infected, (iii) infected + carvedilol, and (iv) not infected + carvedilol.We analyzed parameters related to parasitemia, plasma levels of TNF, IL-10, and CCL2, and cardiac histopathology after the administration of carvedilol for 30 days. We did not observe differences in the maximum peaks of parasitemia in the day of their detection among the groups. The plasma TNF was elevated at 60 days of infection in mice treated or not with carvedilol. However, we observed a decreased CCL2 level and increased IL-10 levels in those infected animals treated with carvedilol, which impacted the reduction of the inflammatory infiltration in cardiac tissue. For this experimentalmodel, carvedilol therapy was not able to alter the levels of circulating parasites butmodulates the pattern of CCL2 and IL-10 mediators when the VL10 strain of T. cruzi was used in C57BL6 mice.
Resposta inflamatória cardíaca e sistêmica em terapia de combinação com inibidor da angiotensina II e Benznidazol durante a infecção experimental pelo Trypanosoma cruzi.
(2016) Leite, Ana Luísa Junqueira; Silva, André Talvani Pedrosa da; Silva, André Talvani Pedrosa da; Lana, Marta de; Machado, Fabiana Simão
A infecção pelo Trypanosoma cruzi desencadeia um processo inflamatório promotor de alterações morfofisiológicas nas células cardíacas. Terapias farmacológicas têm sido propostas objetivando a redução desta resposta inflamatória e, consequentemente, dos danos cardíacos no hospedeiro infectado. Neste estudo, foram avaliadas as ações do inibidor da enzima conversora da angiotensina (ECA) - Enalapril e do benznidazol (Bz), em monoterapia ou terapia de combinação (TC) durante a fase aguda e crônica da infecção experimental pelo T. cruzi. Camundongos C57BL/6 fêmeas foram infectados com 5000 formas tripomastigotas sanguíneas do T. cruzi (VL-10) e tratados durante 20 dias com diferentes doses de Enalapril (25mg/Kg; 20mg/Kg e 15mg/Kg) ou Bz (100mg/Kg; 80mg/Kg e 60mg/Kg) ou Enalapril+Bz (100mg/Kg/25mg/Kg; 80mg/Kg/20mg/Kg; 60mg/Kg/15mg/Kg). A eutanásia ocorreu no 30º e 120º dia após a infecção, sendo o coração conservado para análise histopatológica e avaliação das atividades enzimáticas das metaloproteinases (MMP-2 e MMP-9) e o sangue/plasma destinado aos ensaios imunoenzimáticos (CCL2, CCL5, TNF, IL-10). A TC com o Enalapril e o Bz, administrada na fase aguda da infecção pelo T. cruzi, mostrou-se promissora pela efetiva redução da parasitemia. A TC com 80mg/kg+20mg/kg foi capaz de elevar os níveis plasmáticos de IL-10 durante a fase aguda e mantê-los elevados na fase crônica. De uma forma geral, as TCs reduziram a produção plasmática de do TNF-alfa, CCL2 e CCL5 na fase aguda mantendo, em parte, este perfil durante a fase crônica. A TC não alterou a atividade das MMP-2 e MMP-9 na fase aguda e crônica, com exceção da combinação com 100+25mg/Kg, que resultou em um aumento da atividade da MMP-2 na fase crônica. Além disso, a TC reduziu o infiltrado inflamatório no tecido muscular cardíaco, tanto na fase aguda quanto na fase crônica, e foi eficaz na redução da neoformação de colágeno neste tecido durante a fase crônica. Portanto, conclui-se que esta redução na inflamação plasmática e tecidual observada para as TCs pode levar a uma regulação parcial da inflamação resultando em redução dos danos cardíacos causados pela infecção experimental pelo Trypanosoma cruzi.
The overweight increases circulating inflammatory mediators commonly associated with obesity in young individuals.
(2018) Lopes, Laís Roquete; Ribeiro, Silvana Mara Luz Turbino; Figueiredo, Vivian Paulino; Leite, Ana Luísa Junqueira; Nicolato, Roney Luiz de Carvalho; Estanislau, Juliana de Assis Silva Gomes; Oliveira, Fernando Luiz Pereira de; Silva, André Talvani Pedrosa da
Obesity is a serious and growing world healthy problem affecting developed and developing countries. The new conception of obesity as a basal inflammatory condition has opened a new window of possibilities to identify inflammatory biomarkers to be used in the diagnosis or prognosis of obesity-associated comorbidities. This present work aims the identification of the adipokines (leptin and resistin), chemokines (CCL2, CCL5, CXCL16) and the BMP-2 and their association with the clinical, biochemical (fasting glucose, hemogram, cholesterol, T3, T4 and TSH) and anthropometric (weight, height, body circumferences, skinfold thickness and percentage of body fat) parameters in young adults (18–30 years old) presenting obesity and overweight. Our data showed increasing in anthropometric parameters and in the plasma inflammatory levels in those individuals presenting overweight and obesity. We observed a higher plasma levels of CCL2, CCL5, CXCL16, leptin and resistin in those overweigh and obese individuals. In addition, the CCL2, CCL5 presented a positive correlation with the body mass index and the body fat percentage. Assuming the obesity as a systemic inflammatory process, in this current study, the overweight individuals possess a close similar pattern of circulating inflammatory mediators which might be a potential risk of the development of obesity comorbidities. Further studies are still needed to precise the role of the biomarkers CCL2, CCL5, CXCL16 and BMP-2 in the clinical prognosis related to the overweight or obese individuals.
The β-blocker carvedilol and the benznidazole modulate the cardiac immune response in the acute infection induced by Colombian strain of the Trypanosoma cruzi.
(2018) Horta, Aline Luciano; Figueiredo, Vivian Paulino; Leite, Ana Luísa Junqueira; Costa, Guilherme de Paula; Menezes, Ana Paula de Jesus; Ramos, Camila de Oliveira; Pedrosa, Tamiles Caroline Fernandes; Bezerra, Frank Silva; Vieira, Paula Melo de Abreu; Silva, André Talvani Pedrosa da
BACKGROUND The infection led by Trypanosoma cruzi persists in mammalian tissues causing an inflammatory imbalance. Carvedilol (Cv), a non-selective beta blocker drug indicated to treat heart failure and antihypertensive has shown to promote antioxidant and immunomodulatory properties which might improve the inflammation induced by T. cruzi. OBJECTIVES Evaluate the role of Cv on the inflammatory response of C57BL/6 mice acutely infected with the Colombian strain of T. cruzi. METHODS Animals were infected with the Colombian strain of T. cruzi and treated with Cv (25 mg/kg/day), benznidazole (Bz) (100 mg/kg/day) or their combination. On the 28th day of infection and 23 days of treatment, the euthanasia occurred, and the heart preserved for histopathological, oxidative stress (SOD, catalase, TBARs, carbonylated proteins) and plasma (CCL2, CCL5, TNF, IL-10) analyses. Parasitaemia and survival were assessed along the infection. FINDINGS Cv decreased TBARs, but increased the mortality rate, the parasitaemia and the levels of CCL2, CCL5, catalase and the inflammatory infiltrate in the cardiac tissue. Bz led the reduction of the inflammatory infiltrate and circulating levels of oxidative stress and inflammatory mediators in the infected mice. MAIN CONCLUSIONS Our data suggest that Cv, in this experimental model using the Colombian strain of T. cruzi, caused damage to the host.