Effects of Addition of Tissue‐Type Plasminogen Activator in In Vitro Fertilization Medium on Bovine Embryo Development and Quality

• Published in: Reproduction in domestic animals 2015-02, Vol.50 (1), p.112-120
• Main Authors: Krania, F, Dovolou, E, Rekkas, CA, Theodosiadou, EK, Pappas, I, Amiridis, GS
• Format: Article
• Language: English
• Subjects: Animal reproduction; Animals; apoptosis; Apoptosis - genetics; Blastocyst; Blastocyst - metabolism; cattle; Cattle - embryology; cell cycle; Cell Cycle Checkpoints - genetics; Culture Media; Embryo Culture Techniques; Embryo Implantation - genetics; embryogenesis; Embryonic Development - drug effects; Female; Fertilization in Vitro - methods; Fertilization in Vitro - veterinary; Gene expression; Gene Expression - drug effects; genes; In vitro fertilization; In Vitro Oocyte Maturation Techniques; Livestock; Male; metabolism; Metabolism - genetics; Morula - metabolism; oxidation; Oxidation-Reduction; plasmin; plasminogen; plasminogen activator; Plasminogen Activators - analysis; Plasminogen Inactivators - analysis; Tissue Plasminogen Activator - adverse effects; Tissue Plasminogen Activator - analysis; Tissue Plasminogen Activator - pharmacology; zygote
• ISSN: 0936-6768; 1439-0531
• DOI: 10.1111/rda.12456

Plasminogen activators/Plasmin system plays pivotal role in regulating reproductive functions of mammals. Here, we examined the effects of modification of in vitro fertilization medium (IVF medium) with the addition of tissue‐type plasminogen activator (t‐PA), on bovine embryo development and quality, assessed by quantification of expression of various genes related to metabolism, oxidation, implantation and apoptosis. In addition, plasminogen activator activity (PAA) and plasminogen activator inhibition (PAI) were measured in the spent media. After conventional IVM, 2016 cumulus‐oocyte complexes (COCs) were divided into four groups with modified composition of the IVF medium containing t‐PA and/or its inhibitor epsilon‐aminocaproic acid (control, t‐PA, t‐PA+ε‐ACA, ε‐ACA). Presumptive zygotes were cultured for 8 days in synthetic oviductal fluid (SOF) medium; gene expression studies were carried out on morulae and blastocysts. t‐PA alone significantly suppressed cleavage and blastocyst formation rates, but this effect was neutralized by the addition of ε‐ACA. PAA in the treated group was significantly reduced by ε‐ACA, but without total elimination. Significant differences were detected in the expression of genes related to apoptosis and/or cell cycle arrest (BAX, BCL2L1, KAT2B) between embryos produced in t‐PA‐modified media and controls, giving an overall notion that the inferior developmental competence of treated embryos may be attributed to apoptotic phenomena induced by t‐PA. In conclusion, it appears that excessive t‐PA content in the IVF media, suppresses blastocyst formation rate, possibly due to induction of apoptotic phenomena.