Exogenous activation and inhibition of plasminogen/plasmin activity during in vitro maturation of bovine cumulus-oocyte complexes: A biological and spectroscopic approach

GABRIELA RIZO; ANTONIO DANIEL BARRERA; LUIS EMANUEL JIMENEZ; ELINA VANESA GARCÍA; DANIELA C. GARCIA; MARIELA ROLDÁN-OLARTE

MOLECULAR REPRODUCTION AND DEVELOPMENT

WILEY-LISS, DIV JOHN WILEY & SONS INC

Lugar: New York; Año: 2021

1040-452X

This work deals with the effect of plasminogen/plasmin on in vitro37 maturation (IVM) of bovine cumulus-oocyte complexes (COCs). Exogenous38 plasminogen activator streptokinase (SK) added to the IVM medium revealed39 similar values of cumulus expansion and oocyte nuclear maturation compared to40 controls (standard IVM medium). However, a decrease in both determinations41 was observed in COCs matured with supplementation of ɛ-amino caproic acid (ɛ42 ACA), a specific plasmin inhibitor. After in vitro fertilization, no differences were43 observed in either cleavage or blastocyst rates between SK and control groups;44 however, ε-ACA treatment caused a decrease in both developmental rates. Zona45 pellucida (ZP) digestion time decreased in the SK group while it increased in the46 ε-ACA group. Raman microspectroscopy revealed an increase in the intensity of47 the band corresponding to the glycerol group of sialic acid in the ZP of oocytes48 matured with SK, whereas ZP spectra of oocytes treated with ɛ-ACA presented49 similarities with immature oocytes. The results indicate that although treatment50 with SK did not alter oocyte developmental competence, it induced modifications51 in the ZP of oocytes that could favour gamete interaction. Plasmin inhibition52 impairs oocyte maturation and has an impact on embryo development, thus53 evidencing the importance of this protease during IVM.