Morphologic study of the effect of iron on pseudocyst formation in Trichomonas vaginalis and its interaction with human epithelial cells

Submitted by Sandra Infurna ([email protected]) on 2017-11-09T11:11:13Z No. of bitstreams: 1 geovane_lopes_etal_IOC_2017.pdf: 2178070 bytes, checksum: a46da62a76d42d8f194ab2e1ec37016c (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2017-11-09T11:22:04Z (GMT) No. of bitstreams: 1 geovane_lopes_etal_IOC_2017.pdf: 2178070 bytes, checksum: a46da62a76d42d8f194ab2e1ec37016c (MD5)Made available in DSpace on 2017-11-09T11:22:04Z (GMT). No. of bitstreams: 1 geovane_lopes_etal_IOC_2017.pdf: 2178070 bytes, checksum: a46da62a76d42d8f194ab2e1ec37016c (MD5) Previous issue date: 2017Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular e Doenças Endêmicas. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Pesquisa em Leishmanioses. Rio de Janeiro, RJ, Brasil.Universidade Federal de São João Del Rei. Faculdade de Medicina. Departamento de Medicina. São João Del Rei, MG, Brasil.Universidade Federal de São João Del Rei. Faculdade de Medicina. Departamento de Medicina. São João Del Rei, MG, Brasil.Instituto de Ensino Superior Presidente Tancredo de Almeida Neves. São João Del Rei, MG, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Ultraestrutura Celular. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular e Doenças Endêmicas. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular e Doenças Endêmicas. Rio de Janeiro, RJ, Brasil.Universidade Estadual do Norte Fluminense Darcy Ribeiro. Centro de Biociências e Biotecnologia. Laboratório de Biologia Celular e Tecidual. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Pesquisa em Leishmanioses. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular e Doenças Endêmicas. Rio de Janeiro, RJ, Brasil / Universidade Federal de São João Del Rei. Faculdade de Medicina. Departamento de Medicina. São João Del Rei, MG, Brasil.Trichomonas vaginalis is the aetiological agent of human trichomoniasis, which is one of the most prevalent sexually transmitted diseases in humans. Iron is an important element for the survival of this parasite and the colonisation of the host urogenital tract

CARACTERÍSTICAS SOCIOECONÔMICAS DOS COMERCIANTES DE PLANTAS MEDICINAIS DE CURRAIS NOVOS/RN

As feiras livres são espaços dinâmicos, essenciais à integração socioeconômica entre comunidades, em especial nas cidades de pequeno porte. Dentre os produtos disponíveis, encontram-se as plantas medicinais, importantes recursos terapêuticos para a parcela mais carente da população. Objetivamos determinar as características socioeconômicas e culturais dos comerciantes de plantas medicinais em Currais Novos/RN. A atividade é predominantemente exercida por homens, de baixo poder aquisitivo e escolaridade. O comércio de plantas medicinais é a principal fonte de renda para 67,0% dos entrevistados e os dados apontam tendência à extinção da atividade na feira livre de Currais Novos

Morphologic study of the effect of iron on pseudocyst formation in Trichomonas vaginalis and its interaction with human epithelial cells

BACKGROUND Trichomonas vaginalis is the aetiological agent of human trichomoniasis, which is one of the most prevalent sexually transmitted diseases in humans. Iron is an important element for the survival of this parasite and the colonisation of the host urogenital tract. OBJECTIVES In this study, we investigated the effects of iron on parasite proliferation in the dynamics of pseudocyst formation and morphologically characterised iron depletion-induced pseudocysts. METHODS We performed structural and ultrastructural analyses using light microscopy, scanning electron microscopy and transmission electron microscopy. FINDINGS It was observed that iron depletion (i) interrupts the proliferation of T. vaginalis, (ii) induces morphological changes in typical multiplicative trophozoites to spherical non-proliferative, non-motile pseudocysts, and (iii) induces the arrest of cell division at different stages of the cell cycle; (iv) iron is the fundamental element for the maintenance of typical trophozoite morphology; (v) pseudocysts induced by iron depletion are viable and reversible forms; and, finally, (vi) we demonstrated that pseudocysts induced by iron depletion are able to interact with human epithelial cells maintaining their spherical forms. MAIN CONCLUSIONS Together, these data suggest that pseudocysts could be induced as a response to iron nutritional stress and could have a potential role in the transmission and infection of T. vaginalis

Activity and Cell-Death Pathway in Leishmania infantum Induced by Sugiol: Vectorization Using Yeast Cell Wall Particles Obtained From Saccharomyces cerevisiae

Visceral leishmaniasis, caused by Leishmania infantum, is a neglected tropical disease, to which efforts in the innovation of effective and affordable treatments remain limited, despite the rising incidence in several regions of the world. In this work, the antileishmanial effects of sugiol were investigated in vitro. This compound was isolated from the bark of Cupressus lusitanica and showed promising activity against L. infantum. In spite of the positive results, it is known that the compound is a poorly water-soluble diterpene molecule, which hinders further investigation, especially in preclinical animal studies. Thus, in an alternative delivery method, sugiol was entrapped in glucan-rich particles obtained from Saccharomyces cerevisiae yeast cell walls (YCWPs). To evaluate the activity of sugiol, the experiments were divided into two parts: (i) the in vitro investigation of antileishmanial activity of free sugiol against L. infantum promastigotes after 24, 48, and 72 h of treatment and (ii) the evaluation of antileishmanial activity of sugiol entrapped in glucan-rich particles against intracellular L. infantum amastigotes. Free sugiol induced the cell-death process in promastigotes, which was triggered by enhancing cytosolic calcium level and promoting the autophagy up to the first 24 h. Over time, the presence of autophagic vacuoles became rarer, especially after treatment with lower concentrations of sugiol, but other cellular events intensified, like ROS production, cell shrinkage, and phosphatidylserine exposure. Hyperpolarization of mitochondrial membrane potential was found at 72 h, induced by the mitochondria calcium uptake, causing an increase in ROS production and lipid peroxidation as a consequence. These events resulted in the cell death of promastigotes by secondary necrosis. Sugiol entrapped in glucan-rich particles was specifically recognized by dectin-1 receptor on the plasma membrane of macrophages, the main host cell of Leishmania spp. Electron micrographs revealed particles containing sugiol within the infected macrophages and these particles were active against the intracellular L. infantum amastigotes without affecting the host cell. Therefore, the YCWPs act like a Trojan horse to successfully deliver sugiol into the macrophage, presenting an interesting strategy to deliver water-insoluble drugs to parasitized cells