The effects of communication between female reproductive system cells and bovine oocytes mediated by extracellular vesicles of different estrous cycle stages

Author(s)

Ana Clara Faquineli Cavalcante Mendes de Ávila

• Document type: Master's Dissertation
• Press: Pirassununga.
• Institution: Universidade de São Paulo (USP). Faculdade de Zootecnica e Engenharia de Alimentos (FZE/BT)
• Defense date: 2019-09-04

Examining board members

Juliano Coelho da Silveira; Anna Carolina Denicol; Gisele Zoccal Mingoti; Paula Andrea de Albuquerque Salles Navarro

• Advisor: Juliano Coelho da Silveira

Abstract

Assisted reproductive techniques (ART) are alternatives to infertility and to increase animals\' production. Although these techniques are widely used, they can cause negative consequences since early pregnancy until adult life. Attempts to mimic in vivo environment are applied to improve ARTs. Extracellular vesicles (EVs) secreted by cells are targets of recent studies due to their function in intercellular communication. These vesicles are in body fluids and have bioactive material, as miRNAs, that regulate cell functions by post-transcriptional modulation. The hypothesis of this study is that small EVs secreted by follicular and oviductal cells improve the in vitro maturation and fertilization of cumulus-oocyte complexes (COCs). Our goal was to characterize and to evaluate the effects of small EVs from follicular and oviductal fluids obtained from different bovine estrous cycle stages during in vitro embryo production. For this, EVs were isolated from bovine follicular fluid (FF) and oviductal flushing, characterized and used as supplementation during in vitro maturation and fertilization, respectively. The results demonstrated that small EVs from follicles at different estrous cycle stage have different miRNA profile. The small EVs from FF and their RNA were taken up by COCs during in vitro maturation but did not change blastocyst production rates. However, we demonstrated that small EVs from different follicle origin modulate pathways such as PI3K-Akt and RNA transport and biological processes related to oocyte maturation, ovulation and immune responses in cumulus cells. Small EVs from oviduct at different estrous cycle stage did not improve embryo production rates and embryo quality in our model. Therefore, this study demonstrated that small EVs are modified according to their follicular origin and are able to impact biological processes in bovine cumulus cells. (AU)

• FAPESP's process: 17/02037-0 - Description of a new mechanism involved in cellular communication between female reproductive system cells and oocyte mediated by extracellular vesicles and their impacts on oocyte maturation, fertilization and bovine embryo cleavage
• Grantee: Ana Clara Faquineli Cavalcante Mendes de Ávila
• Support Opportunities: Scholarships in Brazil - Master