10. DIFFERENCES IN MRNA EXPRESSION OF SELENOPROTEINS IN DOMESTIC CAT OOCYTES AND CUMULUS CELLS DURING IN VITRO MATURATION. (August 2019)

• Record Type: Journal Article
• Authors: Niwinska, A.; Faundez, R.; Kautz, E.; Juszczuk-Kubiak, E.
• Is Part Of: Reproductive biomedicine online. Volume 39(2019)Supplement 1
• Page Start: e32
• Publication Date: 2019-08
• Subjects: oxidative stress -- antioxidant enzymes -- feline oocytes -- selenoproteins; Human reproductive technology -- Periodicals; Human embryo -- Periodicals; Reproduction -- Periodicals; 616.692
• DOI: 10.1016/j.rbmo.2019.04.063
• Languages: English
• ISSNs: 1472-6483

Abstract

Abstract : Introduction: Reactive oxygen species (ROS) is one of the major factors that has a direct negative impact on oocyte quality. The presence of antioxidant enzymes including selenoproteins across different mammalian species suggests that defence mechanisms are conserved and are likely to be important for the final steps of in vitro oocyte maturation. Domestic cat serves as a good animal model for future research in conservation breeding of endangered feline species, but also it is a valuable model for studying developmental pathways that can be affected by in vitro culture and maturation of oocytes for many mammalian species including human. Competence of in vitro development of cat oocytes is low in comparison with other model organisms. A major factor affecting the viability of cells during in vitro culture is an increased oxidative stress. Oxidative modifications could be responsible for oocyte incompetence for in vitro maturation (IVM). The objective of this study was to investigate the relative mRNA expression pattern of three genes - Sep15 (selenoprotein 15), Gpx1 (glutathione peroxidase 1) and Sephs2 (selenophosphate synthetase 2), each involved in protection against free radicals, between oocyte and the surrounding cumulus cells during in vitro maturation. Material and methods: Ovaries from healthy, feral, 8-12 months old female domestic cats (n=10), were obtained by ovariectomy in local veterinary clinic. After 48h of culture in maturation media oocytes were collected at different stages (GV n= 40, MII n=75) and pooled in groups. Total RNA was isolated and level of mRNA expression was tested by qPCR method. Results: Results revealed that all three transcripts were detected, independently of the maturation stage. Nevertheless, significantly higher level of Gpx1 and Sephs2 expression was observed in oocytes, compared with their surrounding cumulus cells. Particularly higher level of Gpx1 mRNA expression was observed in MII oocytes (P<0.05), but no quantitative differences in the Sep15 mRNA expression was detected between GV and MII oocytes (P>0.05). Conclusions: In conclusion, our results indicate that Gpx1 and Sephs2 can be involved in in vitro maturation of oocytes and may be a part of anti-oxidant pathways induced by oxidative stress. Further studies should be conducted on the oxidative response pathways in relation to developmental potential of oocytes matured in vitro and conservation of the mechanism in human. This study was financed by the NCN, research project no. 2012/07B/NZ9/02196 and KNOW Leading National Research Centre-Scientific Consortium Healthy Animal - Safe Food No. 05-1/KNOW2/2015