title: Mitochondrial permeability transition pore (MPTP) desensitization increases sea urchin spermatozoa fertilization rate.
abstract: Mitochondrial permeability transition pore (MPTP) is a protein complex whose opening promotes an abrupt increase in mitochondrial inner membrane permeability. Calcium signaling pathways are described in gametes and are involved in the fertilization process. Although mitochondria may act as Ca(2+) store and have a fast calcium-releasing mechanism through MPTP, its contribution to fertilization remains unclear. The work aimed to investigate the MPTP phenomenon in sea urchin spermatozoa and its role on the fertilization. Several pharmacological tools were used to evaluate the MPTP's physiology. Our results demonstrated that MPTP occurs in male gametes in a Ca(2+) - and voltage-dependent manner and it is sensitive to cyclosporine A. Additionally, our data show that MPTP opening does not alter ROS generation in sperm cells. Inhibition of MPTP in spermatozoa strongly improved the fertilization rate, which may involve mechanisms that increase the spermatozoa lifespan. The present work is the first report of the presence of a voltage- and Ca(2+) -dependent MPTP in gametes of invertebrates and indicates MPTP opening as another evolutionary feature shared by sea urchins and mammals. Studies about MPTP in sea urchin male gametes may contribute to the elucidation of several mechanisms involved in sperm infertility.
authors.affiliation: Laboratório de Biologia Celular e do Desenvolvimento, Departamento de Biologia Molecular, Universidade Federal da Paraíba, Campus I, Cidade Universitária, CEP: 58051-900, João Pessoa, Paraíba, Brazil.
authors.forename: Elis
authors.initials: E
authors.lastname: Torrezan-Nitao
authors.affiliation: Laboratório de Biologia Celular e do Desenvolvimento, Departamento de Biologia Molecular, Universidade Federal da Paraíba, Campus I, Cidade Universitária, CEP: 58051-900, João Pessoa, Paraíba, Brazil.
authors.forename: Raianna
authors.initials: R
authors.lastname: Boni
authors.affiliation: Laboratório de Biologia Celular e do Desenvolvimento, Departamento de Biologia Molecular, Universidade Federal da Paraíba, Campus I, Cidade Universitária, CEP: 58051-900, João Pessoa, Paraíba, Brazil. marques@ltf.ufpb.br.
authors.forename: Luis Fernando
authors.initials: LF
authors.lastname: Marques-Santos
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000378:metabolism; D016572:Cyclosporine / Q000494:pharmacology; D005260:Female; D005306:Fertilization / Q000502:physiology*; D008297:Male; D053078:Membrane Potential, Mitochondrial / Q000502:physiology; D008928:Mitochondria / Q000378:metabolism; D033681:Mitochondrial Membrane Transport Proteins / Q000378:metabolism*; D051336:Mitochondrial Membranes / Q000378:metabolism; D000083162:Mitochondrial Permeability Transition Pore; D017382:Reactive Oxygen Species / Q000378:metabolism; D012617:Sea Urchins; D013094:Spermatozoa / Q000378:metabolism*
chemical_list: D015220:Calcium Channels; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D017382:Reactive Oxygen Species; D016572:Cyclosporine; D002118:Calcium
keywords: calcium; fertilization; mitochondrial permeability transition pore; sea urchin; spermatozoa