The Role of S-Adenosylmethionine Sensor in the Metabolic and Epigenetic Profile of the Pre-Implantation Embryo

• Grant number: 23/15734-1
• Support Opportunities: Regular Research Grants
• Duration: March 01, 2024 - February 28, 2026
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: Marcella Pecora Milazzotto
• Grantee: Marcella Pecora Milazzotto
• Host Institution: Centro de Ciências Naturais e Humanas (CCNH). Universidade Federal do ABC (UFABC). Ministério da Educação (Brasil). Santo André , SP, Brazil
• Associated researchers: Camila Bruna de Lima ; Jéssica Ispada ; Marc-André Sirard ; Marcelo Demarchi Goissis
• Associated scholarship(s): 24/09187-0 - Optimization of Handling Protocols and Molecular Evaluation in Bovine Embryos, BP.TT

Abstract

During the early stages of development, the pre-implantation embryo undergoes an intense process of metabolic, molecular, and epigenetic reprogramming, which must be properly orchestrated for it to support the events that will lead to the generation of a new individual. Understanding these mechanisms is of fundamental importance for the development of efficient assisted reproduction techniques. A central event in early development is the reprogramming of nuclear and mitochondrial DNA methylation, which, among other factors, depends on the cell's appropriate metabolic profile. Recent studies have demonstrated the role of the mechanistic target of rapamycin complex 1 (mTORC1) as a common element in the control of mechanisms that directly interfere with DNA methylation profiles. In particular, one of these mechanisms is the S-adenosylmethionine sensor (SAM - the primary donor of methyl groups for DNA methylation), SAMTOR. In the presence of methionine, SAM is synthesized and binds to SAMTOR, leading to the activation of mTORC1 and subsequently the activation of its downstream targets, which include DNA methyltransferase 1 (DNMT1) and hypoxia-inducible factor 1-alpha (HIF-1±), which, in simplified terms, increase DNA methylation and glycolytic pathway activity, respectively. Therefore, in this study, we propose to contribute to the understanding of the role of SAMTOR in metabolic and epigenetic control during embryonic development. To achieve this, SAMTOR knockdown will be performed from the zygote stage, and the produced embryos will be evaluated for the quantity and localization of mTOR, HIF-1±, PDK1, and DNMT1, mitochondrial membrane potential, glycolytic pathway transcripts, and DNA methylation establishment. Additionally, the global DNA methylation profile of nuclear DNA throughout development will be analyzed, as well as the nuclear and mitochondrial methylome profiles under the influence of SAMTOR inhibition. It is expected that these results will contribute to the understanding of the regulatory mechanisms involved in DNA demethylation and de novo methylation processes in embryos, as well as the role of SAMTOR and mTORC1 in this process. (AU)