Активация ооцитов: фундаментальные и клинические аспекты

Abstract

Fertilization and embryogenesis in mammals are initiated by a series of molecular events called ‘oocyte activation.’ This process includes a number of specific fluctuations of calcium ions in the cell with the involvement of specific phospholipase C ζ (PLCζ), an enzyme of spermatozoa introduced into the ooplasm during gamete fusion and recognized as the main factor responsible for inducing oocyte activation. Substantial biochemical and clinical evidence supports the role of PLCζ in this fundamental process, which is very important for the diagnosis and treatment of infertility. This literature review aims to provide some insight in the structure, mechanism of action, and regulation of PLCζ activity in healthy individuals and people with pathological conditions. Oocyte activation deficiency is associated with abnormalities in the structure, expression, and location of this enzyme in spermatozoa. Artificial activation of oocytes using ionophores, which is the only therapeutic option currently available for patients with its insufficiency, is being debated, especially in terms of its potential epigenetic effects on the embryo. Therefore, interest towards the development of human recombinant PLCζ as an alternative treatment is understandable. Researchers are currently discussing the possibility of diagnostic and clinical application of this enzyme to overcome male infertility associated with oocyte activation deficiency, as well as general aspects of this pathology. Key words: oocyte activation, infertility, calcium ions, phospholipase C ζ