Mem Inst Oswaldo Cruz, Rio de Janeiro, 112(10) October 2017
Morphologic study of the effect of iron on pseudocyst formation in Trichomonas vaginalis and its interaction with human epithelial cells
1Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório de Biologia Molecular e Doenças Endêmicas, Rio de Janeiro, RJ, Brasil
2Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório de Pesquisa em Leishmanioses, Rio de Janeiro, RJ, Brasil
3Universidade Federal de São João Del Rei, Faculdade de Medicina, Departamento de Medicina, São João Del Rei, MG, Brasil
4Instituto de Ensino Superior Presidente Tancredo de Almeida Neves, São João Del Rei, MG, Brasil
5Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório de Ultraestrutura Celular, Rio de Janeiro, RJ, Brasil
6Universidade Estadual do Norte Fluminense Darcy Ribeiro, Centro de Biociências e Biotecnologia, Laboratório de Biologia Celular e Tecidual, Rio de Janeiro, RJ, Brasil
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.