EFFECTS OF EXTRACELLULAR VESICLES FROM UTERINE ENVIRONMENT EXPOSED TO NEGATIVE ENERGY BALANCE ON EMBRYO METABOLISM IN CATTLE

• Grant number: 23/15072-9
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: January 30, 2024
• End date: January 29, 2025
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: Juliano Coelho da Silveira
• Grantee: Juliana Germano Ferst
• Supervisor: Patrick Lonergan
• Host Institution: Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Universidade de São Paulo (USP). Pirassununga , SP, Brazil
• Institution abroad: University College Dublin, Ireland
• Associated to the scholarship: 20/13075-2 - Dairy cows metabolic status effects on epigenetic changes in the embryo and endometrium: the role of extracellular vesicles, BP.PD

Abstract

Dairy cows milk production has increased over the past decade as a result of intense genetic selection. However, the advances in genetic selection of dairy herds did not come with an improvement of reproductive parameters. Negative energy balance (NEB) during postpartum period is important risk factor in the establishment of reproductive failure in high producing dairy cows and has significant economic impact due to the reduction in animal production. Therefore, research that aims to understand and increase reproductive rates in dairy cows industry is of extreme global economic importance. Metabolites generated during NEB state such as non-esterified fatty acids (NEFAs) and ²-hydroxybutyrate (BHB), negatively affect reproductive cells. However, there is a gap in knowledge about intercellular communication in the uterine environment of cows affected by NEB and how the uterine environment affected by NEB may have a detrimental effect in early embryonic development in dairy cows. Extracellular vesicles (EVs; exosomes and microvesicles) containing miRNAs and proteins are secreted by uterine cells. The EVs are mediators of intercellular communication, modulate several reproductive processes and can carry molecular signals in response to stressors such as NEB. The uterine environment has a fundamental role in early embryonic development and subsequent fetal growth in cattle. Changes in the uterine environment can affect embryonic development and have consequences even after birth. Also, the optimal metabolism is important to early embryo development and to successful conceptus elongation. In this context, our project intends to investigate the effect of the extracellular vesicles obtained from uterine environment affected by NEB on the embryonic metabolism from dairy cows. Our hypothesis is that the uterine environment altered by NEB affect embryonic metabolism mediated by extracellular vesicles contents, thus deregulating embryonic development. This work will help to understand an important problem in dairy cows production, which is pregnancy loss. Also, it will help choose the best time to transfer embryos into dairy cows. The expertise of Dr. Lonergan's research group in investigates the maternal-conceptus communication in dairy cows would greatly contribute to our research. Furthermore, learning a new technique such as metabolomics would bring a great advance to our research group.