RESUMEN
BACKGROUND: Chagas disease is an infectious disease caused by the parasite Trypanosoma cruzi and is endemic from Latin American countries. The goal of our study was to identify novel genetic loci associated with chronic Chagas cardiomyopathy development in Chagas disease patients from different Latin American populations. METHODS: We performed a cross-sectional, nested case-control study including 3 sample collections from Colombia, Argentina, and Bolivia. Samples were genotyped to conduct a genome-wide association study (GWAS). These results were meta-analyzed with summary statistic data from Brazil, gathering a total of 3413 Chagas disease patients. To identify the functional impact of the associated variant and its proxies, we performed an in silico analysis of this region. RESULTS: The meta-analysis revealed a novel genome-wide statistically significant association with chronic Chagas cardiomyopathy development in rs2458298 (ORâ =â 0.90, 95%CIâ =â 0.87-0.94, P-valueâ =â 3.27â ×â 10-08), nearby the SAC3D1 gene. In addition, further in silico analyses displayed functional relationships between the associated variant and the SNX15, BAFT2, and FERMT3 genes, related to cardiovascular traits. CONCLUSIONS: Our findings support the role of the host genetic factors in the susceptibility to the development of the chronic cardiac form of this neglected disease.
Asunto(s)
Cardiomiopatía Chagásica , Enfermedad de Chagas , Trypanosoma cruzi , Estudios de Casos y Controles , Cardiomiopatía Chagásica/genética , Estudios Transversales , Estudio de Asociación del Genoma Completo , Humanos , Trypanosoma cruzi/genéticaRESUMEN
The aim of the present work was to evaluate the distribution of the different clones of the parasite prevailing after treatment with benznidazole (BZ) and clomipramine (CLO), in mice infected with Trypanosoma cruzi, Casibla isolate which consists of a mixture of two discrete typing units (DTUs). Albino Swiss mice were infected and treated with high and low concentrations of BZ (100 or 6.25 mg/kg), CLO (5 or 1.25 mg/kg), or the combination of both low doses (BZ6.25 + CLO1.25), during the acute phase of experimental infection. Treatment efficacy was evaluated by comparing parasitaemia, survival and tissular parasite presence. For DTUs genotyping, blood, skeletal and cardiac muscle samples were analysed by multiplex quantitative polymerase chain reaction. The combined treatment had similar outcomes to BZ6.25; BZ100 was the most effective treatment, but it failed to reach parasite clearance and produced greater histological alterations. Non-treated mice and the ones treated with monotherapies showed both DTUs while BZ6.25 + CLO1.25 treated mice showed only TcVI parasites in all the tissues studied. These findings suggest that the treatment may modify the distribution of infecting DTUs in host tissues. Coinfection with T. cruzi clones belonging to different DTUs reveals a complex scenario for the treatment of Chagas disease and search for new therapies.
Asunto(s)
Enfermedad de Chagas , Coinfección , Trypanosoma cruzi , Animales , Enfermedad de Chagas/tratamiento farmacológico , Enfermedad de Chagas/parasitología , Combinación de Medicamentos , Genotipo , Ratones , Distribución TisularRESUMEN
Combination therapies based on the available drugs have been proposed as promising therapeutic alternatives for many diseases. Clomipramine (CLO) has been found to modify the evolution of the experimental infection. The objective of this study was to evaluate the combined effect of benznidazole (BZ) and clomipramine (CLO) against different life-stages of Trypanosoma cruzi in vitro and their efficacy in a murine model. Life-stages of T. cruzi, BZ-partially-resistant (Y) strain, were incubated with BZ and CLO and isobolograms and combination index (CI) were obtained. Swiss mice were infected with trypomastigotes and different treatment schedules were performed, each of which consisted of 30 consecutive daily doses. Treatment efficacy was evaluated by comparing parasitemia, qPCR, survival and histological analysis. These results were analyzed using multivariate analysis to determine the combined effect of the drugs in vivo. CLO + BZ showed synergistic activity in vitro against the clinically relevant life-stages of T. cruzi. The most susceptible forms were the intracellular amastigotes (CI: 0.20), followed by trypomastigotes (CI: 0.60), with no toxicity upon mammalian cells. The combination of both drugs CLO (1.25â¯mg/kg) and BZ (6.25â¯mg/kg), in vivo, significantly diminished the parasitic load in blood and the mortality rate. CLO + BZ presented a similar inflammatory response in cardiac and skeletal muscle (amount of inflammatory cells) to BZ (6.25 mg/kg). Finally, the results from the principal component analysis reaffirmed that both drugs administered in combination presented higher activity compared with the individual administration in the acute experimental model.
Asunto(s)
Enfermedad de Chagas/tratamiento farmacológico , Clomipramina/farmacología , Nitroimidazoles/farmacología , Tripanocidas/farmacología , Trypanosoma cruzi/efectos de los fármacos , Animales , Clomipramina/uso terapéutico , Relación Dosis-Respuesta a Droga , Sinergismo Farmacológico , Quimioterapia Combinada , Femenino , Concentración 50 Inhibidora , Masculino , Ratones , Análisis Multivariante , Músculo Esquelético/parasitología , Músculo Esquelético/patología , Miocardio/patología , Nitroimidazoles/uso terapéutico , Parasitemia/tratamiento farmacológico , Análisis de Componente Principal , Reacción en Cadena en Tiempo Real de la Polimerasa , Tripanocidas/uso terapéuticoRESUMEN
Drug repositioning, i.e. use of existing medicals to treat a different illness, is especially rewarding for neglected tropical diseases (NTD), since in this field the pharmaceutical industry is rather reluctant to spend vast investments for drug development. NTDs afflict primarily poor populations in under-developed countries, which minimizes financial profit. Here we investigated the trypanocidal effect of clomipramine, a commercial antipsychotic drug, on Trypanosoma brucei. The data showed that this drug killed the parasite with an IC50 of about 5µM. Analysis of the involved cell death mechanism revealed furthermore an initial autophagic stress response and finally the induction of apoptosis. The latter was substantiated by a set of respective markers such as phosphatidylserine exposition, DNA degradation, loss of the inner mitochondrial membrane potential and characteristic morphological changes. Clomipramine was described as a trypanothione inhibitor, but as judged from our results it also showed DNA binding capacities and induced substantial morphological changes. We thus consider it likely that the drug induces a multifold adverse interaction with the parasite's physiology and induces stress in a way that trypanosomes cannot cope with.
Asunto(s)
Antiprotozoarios/farmacología , Apoptosis , Clomipramina/farmacología , Trypanosoma brucei brucei/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Concentración 50 InhibidoraRESUMEN
Clomipramine (CLO), a tricyclic antidepressant drug, has been used for the treatment of mice infected with Trypanosoma cruzi. In this work we evaluated the effectiveness of CLO treatment upon T. cruzi-infected mice in the chronic phase of the experimental infection using Quantitative polymerase chain reaction (qPCR) and recombinant ELISA. Sixty Swiss albino mice were inoculated with 50 trypomastigote forms of T. cruzi (Tulahuen strain). CLO treatment consisted of 5mg/kg/day during 60days by intraperitoneal injection, beginning on day 90 post infection (p.i) when the mice presented electrocardiographic (ECG) alterations compatible with the chronic phase of the disease. The evolution of experimental infection and the treatment efficacy were studied through survival, electrocardiography, serology using a mixture and individual (1, 2, 13, 30, 36 and SAPA) recombinant proteins from epimastigotes and trypomastigotes of T. cruzi; and qPCR on days 180 and 270 p.i. CLO treatment in the chronic phase decreased the parasite load, reduced the levels of antibodies against antigen 13 throughout 270days p.i and reversed the ECG abnormalities in the treated animals, from 100% of the mice with alterations at the beginning of the treatment to only 20% of the mice with alterations by day 270 p.i. This study shows that qPCR and the use of recombinant antigens are more sensitive to evaluate the effectiveness of the treatment and proves that clomipramine may be considered as a new chemotherapy for the chronic phase of the disease.
Asunto(s)
Enfermedad de Chagas/sangre , Enfermedad de Chagas/tratamiento farmacológico , Clomipramina/uso terapéutico , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Serología/métodos , Trypanosoma cruzi/fisiología , Animales , Anticuerpos Antiprotozoarios/sangre , Enfermedad de Chagas/diagnóstico por imagen , Enfermedad de Chagas/parasitología , ADN Protozoario/sangre , Electrocardiografía , Femenino , Masculino , Ratones , Parasitemia/tratamiento farmacológico , Estándares de Referencia , Análisis de Supervivencia , Resultado del Tratamiento , Trypanosoma cruzi/inmunologíaRESUMEN
Trypanosoma cruzi invasion and replication in cardiomyocytes and other tissues induce cellular injuries and cytotoxic reactions, with the production of inflammatory cytokines and nitric oxide, both sources of reactive oxygen species. The myocyte response to oxidative stress involves the progression of cellular changes primarily targeting mitochondria. Similar alterations could be taking place in mitochondria from the skeletal muscle; if that is the case, a simple skeletal muscle biopsy would give information about the cardiac energetic production that could be used as a predictor of the chagasic cardiopathy evolution. Therefore, in the present paper we studied skeletal muscle mitochondrial structure and the enzymatic activity of citrate synthase and respiratory chain complexes I to IV (CI-CIV), in Albino Swiss mice infected with T. cruzi, Tulahuen strain and SGO Z12 and Lucky isolates, along the infection. Changes in the mitochondrial structure were detected in 100% of the mitochondria analyzed from the infected groups: they all presented at least 1 significant abnormality such as increase in their matrix or disorganization of their cristae, which are probably related to the enzymatic dysfunction. When we studied the Krebs cycle functionality through the measurement of the specific citrate synthase activity, we found it to be significantly diminished during the acute phase of the infection in Tulahuen and SGO Z12 infected groups with respect to the control one; citrate synthase activity from the Lucky group was significantly increased (p<0.05). The activity of this enzyme was reduced in all the infected groups during the chronic asymptomatic phase (p<0.001) and return to normal values (Tulahuen and SGO Z12) or increased its activity (Lucky) by day 365 post-infection (p.i.). When the mitochondrial respiratory chain was analyzed from the acute to the chronic phase of the infection through the measurement of the activity of complexes I to IV, the activity of CI remained similar to control in Tulahuen and Lucky groups, but was significantly augmented in the SGO Z12 one in the acute and chronic phases (p<0.05). CII increased its activity in Tulahuen and Lucky groups by day 75 p.i. and in SGO Z12 by day 365 p.i. (p<0.05). CIII showed a similar behavior in the 3 infected groups, remaining similar to control values in the first two stages of the infection and significantly increasing later on (p<0.0001). CIV showed an increase in its activity in Lucky throughout all stages of infection (p<0.0001) and an increase in Tulahuen by day 365days p.i. (p<0.0001); SGO Z12 on the other hand, showed a decreased CIV activity at the same time. The structural changes in skeletal muscle mitochondria and their altered enzyme activity began in the acute phase of infection, probably modifying the ability of mitochondria to generate energy; these changes were not compensated in the rest of the phases of the infection. Chagas is a systemic disease, which produces not only heart damage but also permanent skeletal muscle alterations.
Asunto(s)
Enfermedad de Chagas/metabolismo , Mitocondrias Musculares/metabolismo , Músculo Esquelético/metabolismo , Animales , Enfermedad de Chagas/patología , Proteínas del Complejo de Cadena de Transporte de Electrón/metabolismo , Femenino , Masculino , Ratones , Mitocondrias Musculares/ultraestructura , Músculo Esquelético/ultraestructuraRESUMEN
Chagasic cardiopathy has become one of the most frequent causes of heart failure and sudden death, as well as one of the most common causes of cardio-embolic stroke in Latin America. The myocyte response to oxidative stress involves the progression of cellular changes, primarily targeting the mitochondria and modifying therefore the energy supply. In this paper we analysed the effect of the infection of mice with 2 different strains of Trypanosoma cruzi (Tulahuen and SGO Z12) in the chronic indeterminate stage (75 days post-infection), upon the structure and function of cardiac mitochondria. The structural results showed that 83% of the mitochondria from the Tulahuen-infected mice presented an increase in their matrix and 91% of the mitochondria from the SGO Z12-infected group showed a reduction in their diameter (P < 0.05). When the Krebs cycle and mitochondrial respiratory chain functionality was analysed through the measurement of the citrate synthase and complexes I to IV activity, it showed that their activity was altered in all cases in a similar manner in both infected groups. In this paper we have demonstrated that the chronic indeterminate phase is not 'silent' and that cardiac mitochondria are clearly involved in the genesis and progression to the chronic chagasic cardiopathy when different factors alter the host-parasite equilibrium.
Asunto(s)
Cardiomiopatía Chagásica/patología , Cardiomiopatía Chagásica/fisiopatología , Corazón/parasitología , Interacciones Huésped-Parásitos , Mitocondrias/enzimología , Mitocondrias/parasitología , Trypanosoma cruzi/patogenicidad , Animales , Cardiomiopatía Chagásica/parasitología , Enfermedad de Chagas/parasitología , Enfermedad de Chagas/patología , Enfermedad de Chagas/fisiopatología , Enfermedad Crónica , Citrato (si)-Sintasa/metabolismo , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Electrocardiografía , Femenino , Corazón/fisiopatología , Humanos , Masculino , Ratones , Mitocondrias/patología , Miocardio/metabolismo , Miocardio/patología , Parasitemia/parasitología , Parasitemia/fisiopatología , Especificidad de la Especie , Trypanosoma cruzi/clasificaciónRESUMEN
Chagas infection is a major endemic disease affecting Latin American countries. The persistence of Trypanosoma cruzi generates a chronic inflammatory reactivity that induces an immune response directed to the host's tissues. The effectiveness of the treatment in the chronic phase is still unsatisfactory due, amongst other reasons, to the collateral effects of the drugs used. We investigated the effect of clomipramine, a tricyclic antidepressant that, when used as a treatment of T. cruzi-chronically infected mice, inhibits trypanothione reductase, an exclusive and vital enzyme of T. cruzi. Clomipramine improved survival (P<0.05) by diminishing the parasite intensity as demonstrated by PCR studies in the heart and skeletal muscle, and significantly prevented the evolution to fibrosis of the inflammatory infiltrates. Clomipramine could be a good candidate for the treatment of chronic Chagas disease.
Asunto(s)
Antidepresivos Tricíclicos/farmacología , Enfermedad de Chagas/tratamiento farmacológico , Clomipramina/farmacología , Corazón/parasitología , Músculo Esquelético/parasitología , Trypanosoma cruzi/inmunología , Animales , Antidepresivos Tricíclicos/administración & dosificación , Enfermedad de Chagas/inmunología , Enfermedad de Chagas/parasitología , ADN Protozoario/química , ADN Protozoario/genética , Femenino , Corazón/efectos de los fármacos , Histocitoquímica , América Latina , Masculino , Ratones , Músculo Esquelético/efectos de los fármacos , Reacción en Cadena de la Polimerasa , Trypanosoma cruzi/genéticaRESUMEN
Host genetic factors have been proposed as determinants of the variable progression of Chagas disease (ChD). Two polymorphisms, H558R and A572D, of the voltage-gated sodium channel α-subunit SCN5A gene were studied in chagasic patients in order to determine their contribution to the susceptibility to the development and/or to the progression of the cardiovascular disease. A total of 104 patients were classified as seronegative or seropositive for Trypanosoma cruzi antibodies. Clinical evaluation, electrocardiograms (ECG) and echocardiograms (Echo) were performed to detect any conduction and/or structural alteration. Patients were classified into: G1: without ECG and/or Echo alterations, G2: with ECG alterations and G3: with ECG and Echo alterations. H558R and A572D polymorphisms were detected by PCR. Cardiac alterations were more frequent in G2 + G3 seropositive patients. For H558R polymorphism, the C allele was significantly increased in seropositive G2 + G3 patients (P = 0.049. OR = 2.08; 95% CI = 1.12-4.33). When comparing the disease cardiac progression (G2 vs G3), the genotypes from the H558R polymorphism were associated to more intense cardiac alterations (P = 0.018). For A572D polymorphism, no associations were found. The results suggest a possible involvement of SCN5A polymorphisms in the susceptibility to chronic ChD and the disease progression, contributing to the elucidation of the molecular mechanism underlying this complex myocardiopathy. In this regard, this is the first work that studies this gene in the context of chagasic cardiomyopathy.
Asunto(s)
Cardiomiopatía Chagásica/genética , Canal de Sodio Activado por Voltaje NAV1.5/genética , Polimorfismo Genético , Adulto , Anciano , Argentina , Cardiomiopatía Chagásica/patología , Femenino , Marcadores Genéticos/genética , Humanos , Masculino , Persona de Mediana Edad , Canal de Sodio Activado por Voltaje NAV1.5/metabolismoRESUMEN
Genetic factors and the immunologic response have been suggested to determine the susceptibility against the infection and the outcome of Chagas disease. In the present study, we analysed three IL17A genetic variants (rs4711998, rs8193036 and rs2275913) regarding the predisposition to Trypanosoma cruzi infection and the development of chronic Chagas cardiomyopathy (CCC) in different Latin American populations. A total of 2,967 individuals from Colombia, Argentina, Bolivia and Brazil, were included in this study. The individuals were classified as seronegative and seropositive for T. cruzi antigens, and this last group were divided into asymptomatic and CCC. For T. cruzi infection susceptibility, the IL17A rs2275913*A showed a significant association in a fixed-effect meta-analysis after a Bonferroni correction (P = 0.016, OR = 1.21, 95%CI = 1.06-1.41). No evidence of association was detected when comparing CCC vs. asymptomatic patients. However, when CCC were compared with seronegative individuals, it showed a nominal association in the meta-analysis (P = 0.040, OR = 1.20, 95%CI = 1.01-1.45). For the IL17A rs4711998 and rs8193036, no association was observed. In conclusion, our results suggest that IL17A rs2275913 plays an important role in the susceptibility to T. cruzi infection and could also be implicated in the development of chronic cardiomyopathy in the studied Latin American population.
Asunto(s)
Enfermedad de Chagas/genética , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad/genética , Interleucina-17/genética , Polimorfismo Genético/genética , Adulto , Anciano , Anciano de 80 o más Años , Enfermedad de Chagas/etiología , Femenino , Humanos , América Latina , Masculino , Metaanálisis como Asunto , Persona de Mediana EdadRESUMEN
The aim of the present study was to analyze IL6 rs1800795 genetic variant in the susceptibility to Trypanosoma cruzi infection and in the development of chronic Chagas cardiomyopathy (CCC), in five independent Latin American cohorts. A total of 3,087 individuals from Latin American countries (Argentina, Bolivia, Peru, and two cohorts from Colombia) were studied. In all cohorts, patients were classified as seropositive for T. cruzi antigens (n= 1,963) and seronegative (n= 1,124). Based on clinical evaluation, the seropositive patients, were classified as CCC (n= 900) and asymptomatic (n= 1,063). No statistically significant differences in the frequency of IL6 rs1800795 between seropositive and seronegative, or between CCC and asymptomatic patients, were found. Furthermore, after the meta-analysis no statistically significant differences were observed. Our results do not support a contribution of IL6 rs1800795 genetic variant in the susceptibility to the infection and the development of chronic Chagas cardiomyopathy in the studied populations.
Asunto(s)
Cardiomiopatía Chagásica/genética , Predisposición Genética a la Enfermedad , Interleucina-6/genética , Polimorfismo de Nucleótido Simple , Adulto , Anciano , Cardiomiopatía Chagásica/etiología , Enfermedad Crónica , Femenino , Humanos , América Latina , Masculino , Persona de Mediana EdadRESUMEN
Proinflammatory and inflammatory mediators induced by Trypanosoma cruzi infection increase the oxidative stress, generating toxicity for cells targeting mitochondria of different tissues. We studied the activity of citrate synthase and complexes I-IV of respiratory chain in mitochondria of blood lymphomonocyte fraction, from albino Swiss mice infected with different isolates of T. cruzi , during Chagas disease evolution. Complexes I-IV were modified in infected groups (p<0.05) in all the stages, and an inflammatory process of different magnitudes was detected in the heart and skeletal muscle according to the isolate. The citrate synthase activity presented modifications in the SGO Z12 and the Tulahuen group (p<0.05). Hearts showed fiber fragmentation and fibrosis; skeletal muscle presented inflammatory infiltrates and in the Tulahuen infected group, there were also amastigote nests. The inflammatory processes produced an oxidative stress that induced different alterations of mitochondrial enzymes activities in the lymphomonocyte fraction that can be detected by a simple blood extraction, suggesting that they could be used as disease markers, especially in the indeterminate phase of Chagas disease.
Asunto(s)
Enfermedad de Chagas/enzimología , Citrato (si)-Sintasa/metabolismo , Complejo IV de Transporte de Electrones/metabolismo , Mitocondrias/enzimología , Animales , Enfermedad de Chagas/metabolismo , Enfermedad de Chagas/fisiopatología , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Masculino , Mitocondrias/parasitología , Mitocondrias/patología , ParasitemiaRESUMEN
Genetic approaches have been proposed for improving the understanding of the causes of differential susceptibility to Trypanosoma cruzi infection and Chagas disease outcome. Polymorphisms in genes involved in the immune/inflammatory response are being studied in order to clarify their possible role in the occurrence or severity of the cardiac and/or gastrointestinal complications. However still today, the number of significant associated genes is limited and the pathophysiological mechanisms underlying this condition are unknown. This article review the information currently available from the published scientific literature regarding the genetic variants of molecules of the immune system and other variants that can contribute to the clinical presentation of the disease. Genomic medicine will improve our knowledge about the molecular basis of Chagas disease, will open new avenues for developing biomarkers of disease progression, new therapeutic strategies to suit the requirements of individual patients, and will contribute to the control of one of the infections with the greatest socio-economic impact in the Americas.
Asunto(s)
Enfermedad de Chagas/genética , Enfermedad de Chagas/tratamiento farmacológico , Progresión de la Enfermedad , Genómica , Humanos , Polimorfismo GenéticoRESUMEN
Host genetic factors have been suggested to play an important role in the susceptibility to Chagas disease. Given the influence of interleukin 18 (IL-18) in the development of the disease, in the present study, we analyzed three IL18 genetic variants (rs2043055, rs1946518, rs360719) regarding the predisposition to Trypanosoma cruzi infection and the development of chronic Chagas cardiomyopathy (CCC), in different Latin America populations. Genetic data of 3,608 patients from Colombia, Bolivia, Argentina, and Brazil were meta-analyzed to validate previous findings with increased statistical power. Seropositive and seronegative individuals were compared for T. cruzi infection susceptibility. In the Colombian cohort, the allelic frequencies of the three variants showed a significant association, with adjustment for sex and age, and also after applying multiple testing adjustments. Among the Colombian and Argentinean cohorts, rs360719 showed a significant genetic effect in a fixed-effects meta-analysis after a Bonferroni correction (OR: 0.76, CI: 0.66-0.89, P = 0.001). For CCC, the rs2043055 showed an association with protection from cardiomyopathy in the Colombian cohort (OR: 0.79, CI: 0.64-0.99, P = 0.037), with adjustment for sex and age, and after applying multiple testing adjustments. The meta-analysis of the CCC vs. asymptomatic patients from the four cohorts showed no evidence of association. In conclusion, our results validated the association found previously in the Colombian cohort suggesting that IL18 rs360719 plays an important role in the susceptibility to T. cruzi infection and no evidence of association was found between the IL18 genetic variants and CCC in the Latin American population studied.
Asunto(s)
Enfermedad de Chagas/genética , Interleucina-18/genética , Polimorfismo de Nucleótido Simple , Adulto , Anciano , Argentina , Bolivia , Brasil , Enfermedad de Chagas/parasitología , Estudios de Cohortes , Colombia , Femenino , Predisposición Genética a la Enfermedad , Hispánicos o Latinos/genética , Humanos , América Latina , Masculino , Persona de Mediana Edad , Trypanosoma cruzi/fisiología , Adulto JovenRESUMEN
In the present work, we evaluated the effect of mixed Trypanosoma cruzi infections, studying the biological distribution of the different parasites in blood, heart and skeletal muscle during the acute phase. Albino Swiss mice were infected with different parasite strain/isolates or with a combination of them. The parasites in the different tissues were typified through specific PCR, population variability was analyzed through RFLP studies and parasitological and histopathological parameters were evaluated. We found a predominance of TcII and TcVI in all tissues samples respect to TcV and different parasite populations were found in circulation and in the tissues from the same host. These results verify the distribution of parasites in host tissues from early stages of infection and show biological interactions among different genotypes and populations of T. cruzi.
Asunto(s)
Enfermedad de Chagas/parasitología , Trypanosoma cruzi/fisiología , Animales , Enfermedad de Chagas/sangre , Enfermedad de Chagas/patología , Femenino , Genotipo , Corazón/parasitología , Humanos , Masculino , Ratones , Músculo Esquelético/parasitología , Músculo Esquelético/patología , Reacción en Cadena de la Polimerasa , Distribución Tisular , Trypanosoma cruzi/genética , Trypanosoma cruzi/crecimiento & desarrolloRESUMEN
Background: Mitochondrial activity is essential for cardiac and skeletal muscle. The relationship between mitochondrial dysfunction and different cardiovascular conditions has been well described. Pharmacological treatment for heart failure involves different drugs as: angiotensin-converting enzyme inhibitors, B-adrenergic blockers, digitalis glycosides and diuretics. The clinical benefit from medication is clear, however, the role of this drugs in mitochondrial metabolisms is not well understood. Aim of the study: The objective of our study was to analyze structural and functional characteristics of cardiac and skeletal muscle mitochondria in mice treated with drugs normally used for heart failure and compare it to a control group. Methods: Twenty-five Albino Mice divided in five groups were treated with heart failure medication during 30 days (group I to IV). 30 days after treatment they were sacrificed, heart and skeletal muscle were analyzed and compared with a control group (V). Results: Enzymatic activity was slightly increased in groups treated with heart failure medication compared to control group (p>0.05). Mitochondrial morphology was significantly altered in groups treated compared to control group, in addition, mitochondrial area was significantly increased in the treated groups, in both cardiac and skeletal muscle. Conclusions: We concluded that heart failure medication could produce modifications in mitochondrial function; we believe that mitochondria maintains the enzymatic activity by increasing size and modifying morphology. Methods: Twenty-five Albino Mice divided in five groups were treated with heart failure medication during 30 days (group I to IV). 30 days after treatment they were sacrificed, heart and skeletal muscle were analyzed and compared with a control group (V). Results: Enzymatic activity was slightly increased in groups treated with heart failure medication compared to control group (p>0.05). Mitochondrial morphology was significantly altered in groups treated compared to control group, in addition, mitochondrial area was significantly increased in the treated groups, in both cardiac and skeletal muscle. Conclusions: We concluded that heart failure medication could produce modifications in mitochondrial function; we believe that mitochondria maintains the enzymatic activity by increasing size and modifying morphology. Results: Enzymatic activity was slightly increased in groups treated with heart failure medication compared to control group (p>0.05). Mitochondrial morphology was significantly altered in groups treated compared to control group, in addition, mitochondrial area was significantly increased in the treated groups, in both cardiac and skeletal muscle. Conclusions: We concluded that heart failure medication could produce modifications in mitochondrial function; we believe that mitochondria maintains the enzymatic activity by increasing size and modifying morphology. Conclusions: We concluded that heart failure medication could produce modifications in mitochondrial function; we believe that mitochondria maintains the enzymatic activity by increasing size and modifying morphology.
Introducción: la actividad mitocondrial es esencial para el músculo cardíaco y esquelético. La relación entre la disfunción mitocondrial y diferentes condiciones cardiovasculares ha sido bien descrita. El tratamiento farmacológico de la insuficiencia cardíaca implica diferentes medicamentos como: inhibidores de la enzima convertidora de la angiotensina, bloqueadores B-adrenérgicos, glucósidos digitálicos y diuréticos. Los beneficios clínicos del tratamiento son claros, sin embargo, el papel de estos fármacos en el metabolismo mitocondrial no esta bien establecido.Objetivo del estudio: El objetivo de nuestro estudio fue analizar las características estructurales y funcionales de las mitocondrias del músculo cardíaco y esquelético en ratones tratados con fármacos habitualmente utilizados para la insuficiencia cardíaca y compararlo con un grupo control.Métodos: Veinticinco ratones albinos divididos en cinco grupos fueron tratados con la medicación para insuficiencia cardíaca durante 30 días (grupo I a IV). 30 días después del tratamiento se sacrificaron, el corazón y el músculo esquelético se analizaron y se compararon con un grupo control (V).Resultados: La actividad enzimática se incrementó ligeramente en los grupos tratados con medicamentos insuficiencia cardiaca en comparación con el grupo control (p> 0,05). morfología mitocondrial se modificó significativamente en los grupos tratados en comparación con el grupo control, además, el área mitocondrial fue significativamente mayor en los grupos tratados, tanto en el músculo cardíaco y estriado.Conclusiones: Concluimos que la medicación insuficiencia cardíaca podría producir modificaciones en la función mitocondrial; creemos que las mitocondrias pueden mantener la actividad enzimática mediante el aumento de tamaño y modificación de la morfología. Objetivo: El objetivo de nuestro estudio fue analizar las características estructurales y funcionales de las mitocondrias del músculo cardíaco y esquelético en ratones tratados con fármacos habitualmente utilizados para la insuficiencia cardíaca y compararlo con un grupo control. Métodos: Veinticinco ratones albinos divididos en cinco grupos fueron tratados con la medicación para insuficiencia cardíaca durante 30 días (grupo I a IV). 30 días después del tratamiento se sacrificaron, el corazón y el músculo esquelético se analizaron y se compararon con un grupo control (V).Resultados: La actividad enzimática se incrementó ligeramente en los grupos tratados con medicamentos insuficiencia cardiaca en comparación con el grupo control (p> 0,05). morfología mitocondrial se modificó significativamente en los grupos tratados en comparación con el grupo control, además, el área mitocondrial fue significativamente mayor en los grupos tratados, tanto en el músculo cardíaco y estriado.Conclusiones: Concluimos que la medicación insuficiencia cardíaca podría producir modificaciones en la función mitocondrial; creemos que las mitocondrias pueden mantener la actividad enzimática mediante el aumento de tamaño y modificación de la morfología. Resultados: La actividad enzimática se incrementó ligeramente en los grupos tratados con medicamentos insuficiencia cardiaca en comparación con el grupo control (p> 0,05). morfología mitocondrial se modificó significativamente en los grupos tratados en comparación con el grupo control, además, el área mitocondrial fue significativamente mayor en los grupos tratados, tanto en el músculo cardíaco y estriado.Conclusiones: Concluimos que la medicación insuficiencia cardíaca podría producir modificaciones en la función mitocondrial; creemos que las mitocondrias pueden mantener la actividad enzimática mediante el aumento de tamaño y modificación de la morfología. Conclusiones: Concluimos que la medicación insuficiencia cardíaca podría producir modificaciones en la función mitocondrial; creemos que las mitocondrias pueden mantener la actividad enzimática mediante el aumento de tamaño y modificación de la morfología.
Asunto(s)
Antihipertensivos/uso terapéutico , Cardiotónicos/farmacología , Diuréticos/farmacología , Insuficiencia Cardíaca/tratamiento farmacológico , Dinitrato de Isosorbide/farmacología , Mitocondrias Cardíacas/efectos de los fármacos , Animales , Antihipertensivos/farmacología , Atenolol/farmacología , Digoxina/farmacología , Modelos Animales de Enfermedad , Electrocardiografía , Enalapril/farmacología , Femenino , Furosemida/farmacología , Insuficiencia Cardíaca/fisiopatología , Masculino , Ratones , Mitocondrias Cardíacas/fisiología , Mitocondrias Cardíacas/ultraestructura , Espironolactona/farmacologíaRESUMEN
Thioridazine (TDZ) is a phenothiazine that has been shown to be one of the most potent phenothiazines to inhibit trypanothione reductase irreversibly. Trypanothione reductase is an essential enzyme for the survival of Trypanosoma cruzi in the host. Here, we reviewed the use of this drug for the treatment of T. cruzi experimental infection. In our laboratory, we have studied the effect of TDZ for the treatment of mice infected with different strains of T. cruzi and treated in the acute or in the chronic phases of the experimental infection, using two different schedules: TDZ at a dose of 80 mg/kg/day, for 3 days starting 1h after infection (acute phase), or TDZ 80 mg/kg/day for 12 days starting 180 days post infection (d.p.i.) (chronic phase). In our experience, the treatment of infected mice, in the acute or in the chronic phases of the infection, with TDZ led to a large reduction in the mortality rates and in the cardiac histological and electrocardiographical abnormalities, and modified the natural evolution of the experimental infection. These analyses reinforce the importance of treatment in the chronic phase to decrease, retard or stop the evolution to chagasic myocardiopathy. Other evidence leading to the use of this drug as a potential chemotherapeutic agent for Chagas disease treatment is also revised.
Asunto(s)
Enfermedad de Chagas/tratamiento farmacológico , Inhibidores Enzimáticos/farmacología , NADH NADPH Oxidorreductasas/antagonistas & inhibidores , Tioridazina/farmacología , Animales , Relación Dosis-Respuesta a Droga , Ratones , Trypanosoma cruzi/efectos de los fármacos , Trypanosoma cruzi/enzimologíaRESUMEN
BACKGROUND AND AIMS: The fundamental mechanisms involved in the genesis and progression of heart failure are not clearly understood. The present study was conducted to analyze the cardiac mitochondrial involvement in heart failure, the possible parallelism between cardiac and skeletal muscle and if there is a link between clinical symptoms and mitochondrial damage. METHODS: Left ventricle and pectoral biopsies were obtained from patients with heart failure (n: 21) and patients with inter-auricular communication as the unique diagnosis for surgery (n: 6). Mitochondria were isolated from these tissues and studied through electron microscopy, spectrophotometry to measure the activity of respiratory complex III and immunohistochemistry to determine the presence of reactive oxygen species. RESULTS: More than 90% of cardiac and skeletal muscle mitochondria presented structural and functional alterations in relation to an increment in the reactive oxygen species production, even in patients without the presence of any clinical Framingham criteria. CONCLUSIONS: We demonstrated some parallelism between cardiac and skeletal muscle mitochondrial alterations in patients with heart failure and that these alterations begin before the major clinical Framingham criteria are installed, pointing to mitochondria as one of the possibly responsible factors for the evolution of cardiac disease.
Asunto(s)
Insuficiencia Cardíaca/metabolismo , Insuficiencia Cardíaca/patología , Mitocondrias Musculares/metabolismo , Mitocondrias Musculares/patología , Músculo Esquelético/metabolismo , Músculo Esquelético/patología , Miocardio/metabolismo , Miocardio/patología , Anciano , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mitocondrias Musculares/ultraestructura , Músculo Esquelético/ultraestructura , Miocardio/ultraestructura , Especies Reactivas de Oxígeno/metabolismoRESUMEN
We evaluated the presence and distribution of two Trypanosoma cruzi natural isolates in blood, heart, skeletal muscle, liver, and spleen tissues in the acute phase of the experimental infection (35 days postinfection) in order to determine if the populations present in blood were different to those found in the tissues of the same host. Thirty mice were infected with 50 forms of each isolate or with a combination of them. Presence and molecular characterization of the parasites in the host tissues were determined by specific PCR. Cardiac and skeletal muscle alterations were analyzed by histological studies. T. cruzi variability in the host tissues was analyzed through RFLP studies. Both isolates used consisted of a mixture of two T. cruzi lineages. Specific PCRs were positive for most of the samples from the 3 groups analyzed. Cardiac and skeletal muscle sections from the groups infected with one isolate presented mild to moderate inflammatory infiltrates; the group infected with both isolates showed severe inflammatory infiltrates and the presence of amastigote nests in both tissues. Different parasite populations were found in circulation and in the tissues from the same host. These results are important for patients with high probability of mixed infections in endemic areas and contribute to the knowledge of parasite/host interactions.
Asunto(s)
Sangre/parasitología , Enfermedad de Chagas/parasitología , Variación Genética , Trypanosoma cruzi/clasificación , Trypanosoma cruzi/aislamiento & purificación , Animales , Enfermedad de Chagas/patología , ADN Protozoario/genética , Modelos Animales de Enfermedad , Femenino , Genotipo , Masculino , Ratones , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción , Trypanosoma cruzi/genéticaRESUMEN
Alternative strategies are being designed to identify candidates among drugs already available on the market that could be used in combination to improve the efficacy of Chagas disease treatment. This work evaluates the effect of the association of clomipramine (CLO) with benznidazole (BZN) for the treatment of experimental Chagas disease in the acute stage, in Swiss albino mice infected with Trypanosoma cruzi Tulahuen strain. Infected mice were treated with CLO 5mg/kg/day and BZN 50 and 100mg/kg/day, each separately or together. Efficacy of the treatment was evaluated through parasitemia, survival, electrocardiography, histopathological studies, serological and PCR assays at 90 days post-infection (dpi). All treatments significantly (P<0.05) reduced mortality and decreased parasitemia. Histopathological analysis of liver and kidneys of mice treated with CLO and the drug combination showed less injury than mice treated only with BZN. The lower dose of BZN (50mg/kg/day) combined with CLO showed the same efficacy as the habitual dose of BZN (100mg/kg/day) combined with CLO. The therapeutic results from the combination of BZN with CLO presented lesser side effects than the treatment with BZN.