Oral Administration of GW788388, an Inhibitor of Transforming Growth Factor Beta Signaling, Prevents Heart Fibrosis in Chagas Disease

Cardiac damage and dysfunction are prominent features in patients with chronic Chagas disease, which is caused by infection with the protozoan parasite Trypanosoma cruzi (T. cruzi) and affects 10–12 million individuals in South and Central America. Our group previously reported that transforming growth factor beta (TGFß) is implicated in several regulatory aspects of T. cruzi invasion and growth and in host tissue fibrosis. In the present work, we evaluated the therapeutic action of an oral inhibitor of TGFß signaling (GW788388) administered during the acute phase of experimental Chagas disease. GW788388 treatment significantly reduced mortality and decreased parasitemia. Electrocardiography showed that GW788388 treatment was effective in protecting the cardiac conduction system, preserving gap junction plaque distribution and avoiding the development of cardiac fibrosis. Inhibition of TGFß signaling in vivo appears to potently decrease T. cruzi infection and to prevent heart damage in a preclinical mouse model. This suggests that this class of molecules may represent a new therapeutic tool for acute and chronic Chagas disease that warrants further pre-clinical exploration. Administration of TGFß inhibitors during chronic infection in mouse models should be further evaluated, and future clinical trials should be envisaged

A Phosphoproteomic Approach towards the Understanding of the Role of TGF-β in Trypanosoma cruzi Biology

Transforming growth factor beta (TGF-β) plays a pivotal role in Chagas disease, not only in the development of chagasic cardiomyopathy, but also in many stages of the T. cruzi life cycle and survival in the host cell environment. The intracellular signaling pathways utilized by T. cruzi to regulate these mechanisms remain unknown. To identify parasite proteins involved in the TGF-β response, we utilized a combined approach of two-dimensional gel electrophoresis (2DE) analysis and mass spectrometry (MS) protein identification. Signaling via TGF-β is dependent on events of phosphorylation, which is one of the most relevant and ubiquitous post-translational modifications for the regulation of gene expression, and especially in trypanosomatids, since they lack several transcriptional control mechanisms. Here we show a kinetic view of T. cruzi epimastigotes (Y strain) incubated with TGF-β for 1, 5, 30 and 60 minutes, which promoted a remodeling of the parasite phosphorylation network and protein expression pattern. The altered molecules are involved in a variety of cellular processes, such as proteolysis, metabolism, heat shock response, cytoskeleton arrangement, oxidative stress regulation, translation and signal transduction. A total of 75 protein spots were up- or down-regulated more than twofold after TGF-β treatment, and from these, 42 were identified by mass spectrometry, including cruzipain–the major T. cruzi papain-like cysteine proteinase that plays an important role in invasion and participates in the escape mechanisms used by the parasite to evade the host immune system. In our study, we observed that TGF-β addition favored epimastigote proliferation, corroborating 2DE data in which proteins previously described to be involved in this process were positively stimulated by TGF-β

Pivotal role for TGF-beta in infectious heart disease: The case of Trypanosoma cruzi infection and consequent Chagasic myocardiopathy

International audienceThis paper summarizes recent data from the literature suggesting that transforming growth factor-beta (TGF-beta) participates at least in four different processes influencing development of myocardiopathy in Chagas disease, a major parasitic illness caused by Trypanosoma cruzi infection: (a) invasion of cardiac fibroblasts and myocytes; (b) intracellular parasite cycle; (c) regulation of inflammation and immune response; (d) fibrosis and heart remodeling during acute and chronic disease. All these effects point to an important role of TGF-beta in Chagas disease myocardiopathy and suggest that monitoring the circulating levels of this cytokine could be of help in clinical prognosis and management of patients. Moreover, TGF-beta-interfering therapies appear as interesting adjuvant interventions during acute and chronic phases of T. cruzi infection

Gap junction reduction in cardiomyocytes following transforming growth factor- β treatment and Trypanosoma cruzi infection

Submitted by Sandra Infurna ([email protected]) on 2018-09-21T18:00:35Z No. of bitstreams: 1 taniac_araujorge_etal_IOC_2009.pdf: 568732 bytes, checksum: d374b12e3a5075c3233ac5c4c1e81696 (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2018-09-21T18:37:48Z (GMT) No. of bitstreams: 1 taniac_araujorge_etal_IOC_2009.pdf: 568732 bytes, checksum: d374b12e3a5075c3233ac5c4c1e81696 (MD5)Made available in DSpace on 2018-09-21T18:37:48Z (GMT). No. of bitstreams: 1 taniac_araujorge_etal_IOC_2009.pdf: 568732 bytes, checksum: d374b12e3a5075c3233ac5c4c1e81696 (MD5) Previous issue date: 2009Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Inovações Terapêuticas, Ensino e Bioprodutos. Rio de Janeiro, RJ, Brasil / Autonomic Neuroscience Centre. Royal Free and University College Medical School. Rowland Hill Street, London, UK .Autonomic Neuroscience Centre. Royal Free and University College Medical School. Rowland Hill Street, London, UK /Universidade Federal do Rio de Janeiro. Centro de Ciências da Saúde. Instituto de Biofísica Carlos Chagas Filho. Rio de Janeiro, RJ, Brasil.Institut National de la Santé et de la Recherche Médicale. Unité 878, and Commissariat à l’Énergie Atomique. Institut de Recherches en Technologies et Sciences pour le Vivant. Grenoble, France.Universidade de São Paulo. Faculdade de Medicina. Instituto do Coração. São Paulo, SP, Brasil.Department of Anatomy and Developmental Biology. University College London. Gower Street, London, UK.Autonomic Neuroscience Centre. Royal Free and University College Medical School. Rowland Hill Street, London, UK .Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Inovações Terapêuticas, Ensino e Bioprodutos. Rio de Janeiro, RJ, Brasil.Gap junction connexin-43 (Cx43) molecules are responsible for electrical impulse conduction in the heart and are affected by transforming growth factor-β (TGF-β). This cytokine increases during Trypanosoma cruzi infection, modulating fibrosis and the parasite cell cycle. We studied Cx43 expression in cardiomyocytes exposed or not to TGF-β T. cruzi, or SB-431542, an inhibitor of TGF-β receptor type I (ALK-5). Cx43 expression was also examined in hearts with dilated cardiopathy from chronic Chagas disease patients, in which TGF-β signalling had been shown previously to be highly activated. We demonstrated that TGF-β treatment induced disorganised gap junctions in non-infected cardiomyocytes, leading to a punctate, diffuse and non-uniform Cx43 staining. A similar pattern was detected in T. cruzi-infected cardiomyocytes concomitant with high TGF-β secretion. Both results were reversed if the cells were incubated with SB-431542. Similar tests were performed using human chronic chagasic patients and we confirmed a down-regulation of Cx43 expression, an altered distribution of plaques in the heart and a significant reduction in the number and length of Cx43 plaques, which correlated negatively with cardiomegaly. We conclude that elevated TGF-β levels during T. cruzi infection promote heart fibrosis and disorganise gap junctions, possibly contributing to abnormal impulse conduction and arrhythmia that characterise severe cardiopathy in Chagas disease

Pharmacological Inhibition of Transforming Growth Factor β Signaling Decreases Infection and Prevents Heart Damage in Acute Chagas' Disease▿

Chagas' disease induced by Trypanosoma cruzi infection is an important cause of mortality and morbidity affecting the cardiovascular system for which presently available therapies are largely inadequate. We previously reported that transforming growth factor β (TGF-β) is implicated in several regulatory aspects of T. cruzi invasion and growth and in host tissue fibrosis. This prompted us to evaluate the therapeutic action of an inhibitor of TGF-β signaling (SB-431542) administered during the acute phase of experimental Chagas' disease. Male Swiss mice were infected intraperitoneally with 104 trypomastigotes of T. cruzi (Y strain) and evaluated clinically for the following 30 days. SB-431542 treatment significantly reduced mortality and decreased parasitemia. Electrocardiography showed that SB-431542 treatment was effective in protecting the cardiac conduction system. By 14 day postinfection, enzymatic biomarkers of tissue damage indicated that muscle injury was decreased by SB-431542 treatment, with significantly lower blood levels of aspartate aminotransferase and creatine kinase. In conclusion, inhibition of TGF-β signaling in vivo appears to potently decrease T. cruzi infection and to prevent heart damage in a preclinical mouse model. This suggests that this class of molecules may represent a new therapeutic agent for acute and chronic Chagas' disease that warrants further clinical exploration

Gap junction reduction in cardiomyocytes following transforming growth factor- β treatment and Trypanosoma cruzi infection

Gap junction connexin-43 (Cx43) molecules are responsible for electrical impulse conduction in the heart and are affected by transforming growth factor-β (TGF-β). This cytokine increases during Trypanosoma cruzi infection, modulating fibrosis and the parasite cell cycle. We studied Cx43 expression in cardiomyocytes exposed or not to TGF-β T. cruzi, or SB-431542, an inhibitor of TGF-β receptor type I (ALK-5). Cx43 expression was also examined in hearts with dilated cardiopathy from chronic Chagas disease patients, in which TGF-β signalling had been shown previously to be highly activated. We demonstrated that TGF-β treatment induced disorganised gap junctions in non-infected cardiomyocytes, leading to a punctate, diffuse and non-uniform Cx43 staining. A similar pattern was detected in T. cruzi-infected cardiomyocytes concomitant with high TGF-β secretion. Both results were reversed if the cells were incubated with SB-431542. Similar tests were performed using human chronic chagasic patients and we confirmed a down-regulation of Cx43 expression, an altered distribution of plaques in the heart and a significant reduction in the number and length of Cx43 plaques, which correlated negatively with cardiomegaly. We conclude that elevated TGF-β levels during T. cruzi infection promote heart fibrosis and disorganise gap junctions, possibly contributing to abnormal impulse conduction and arrhythmia that characterise severe cardiopathy in Chagas disease

Implication of transforming growth factor-beta1 in Chagas disease myocardiopathy

Submitted by Janaína Nascimento ([email protected]) on 2020-01-10T14:41:27Z No. of bitstreams: 1 ve_Araújo-Jorge_Tania_etal_INI_2002.pdf: 710663 bytes, checksum: 95b250936581295bc2ae1ec1c136b1a7 (MD5)Approved for entry into archive by Janaína Nascimento ([email protected]) on 2020-01-10T14:54:13Z (GMT) No. of bitstreams: 1 ve_Araújo-Jorge_Tania_etal_INI_2002.pdf: 710663 bytes, checksum: 95b250936581295bc2ae1ec1c136b1a7 (MD5)Made available in DSpace on 2020-01-10T14:54:13Z (GMT). No. of bitstreams: 1 ve_Araújo-Jorge_Tania_etal_INI_2002.pdf: 710663 bytes, checksum: 95b250936581295bc2ae1ec1c136b1a7 (MD5) Previous issue date: 2002Fundação Oswaldo Cruz. Instituto de Pesquisa Clínica Evandro Chagas. Departamento de Ultra-Estrutura e Biologia Celular. Laboratório de Biologia Celular. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto de Pesquisa Clínica Evandro Chagas. Departamento de Ultra-Estrutura e Biologia Celular. Laboratório de Biologia Celular. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto de Pesquisa Clínica Evandro Chagas. Departamento de Pesquisa Clínica. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto de Pesquisa Clínica Evandro Chagas. Departamento de Pesquisa Clínica. Rio de Janeiro, RJ, Brasil.University of São Paulo. Heart Institute. Service of Pathology. São Paulo, SP, Brazil.INSERM 105. Commissariat à l’Energie Atomique. Department of Cellular Responses and Dynamics. Grenoble, France.INSERM 105. Commissariat à l’Energie Atomique. Department of Cellular Responses and Dynamics. Grenoble, France.INSERM 105. Commissariat à l’Energie Atomique. Department of Cellular Responses and Dynamics. Grenoble, France.Cardiac dysfunction with progressive fibrosis is a hallmark of Chagas disease. To evaluate the involvement of transforming growth factor (TGF)-beta1 in this disease, TGF-beta1 levels in patients were measured at 3 stages: asymptomatic indeterminate (IND), cardiac with no or slight heart dysfunction (Card 1), and cardiac with moderate or severe heart dysfunction (Card 2). All patients had significantly higher circulating levels of TGF-beta1 than did healthy persons, and 27% of patients in the Card 1 group had higher TGF-beta1 levels than did patients in the IND group. Immunohistochemical analysis of cardiac biopsy specimens showed strong fibronectin staining in the extracellular matrix and staining for phosphorylated Smad 2 (activation of the TGF-beta1 signaling pathway) in cell nuclei. The higher levels of latent TGF-beta1 observed in patients with myocardiopathy, together with intracellular activation of the TGF-beta1 pathway and tissue fibrosis, suggest that TGF-beta1 plays an important role in Chagas disease. TGF-beta1 may represent a new target for preventive and curative treatments of Chagas disease

SB-431542, a Transforming Growth Factor β Inhibitor, Impairs Trypanosoma cruzi Infection in Cardiomyocytes and Parasite Cycle Completion▿

The antiinflammatory cytokine transforming growth factor β (TGF-β) plays an important role in Chagas disease, a parasitic infection caused by the protozoan Trypanosoma cruzi. In the present study, we show that SB-431542, an inhibitor of the TGF-β type I receptor (ALK5), inhibits T. cruzi-induced activation of the TGF-β pathway in epithelial cells and in cardiomyocytes. Further, we demonstrate that addition of SB-431542 greatly reduces cardiomyocyte invasion by T. cruzi. Finally, SB-431542 treatment significantly reduces the number of parasites per infected cell and trypomastigote differentiation and release. Taken together, these data further confirm the major role of the TGF-β signaling pathway in both T. cruzi infection and T. cruzi cell cycle completion. Our present data demonstrate that small inhibitors of the TGF-β signaling pathway might be potential pharmacological tools for the treatment of Chagas disease

Distribution of the identified proteins into functional groups.

<p>Bar graphs presenting the functional groups of proteins that had their expression (red) or phosphorylation (green) regulated by TGF-β.</p