Modulation of the glycolitic pathway in bovine embryos in vitro produced: impacts in histone acetylation under the metaboloepigenetics view

Abstract

Modifications of the in vitro embryo production system may be determinant for the adequate development of the pre-implantation embryo. Modifications related to energy metabolism, such as increased or decreased availability of substrates, may have consequences not only in survival but also in molecular control of the embryo. At the beginning of development, pyruvate and to some extent lactate, glutamine and aspartate are the preferred substrates for energy generation and, with the increase in energy demand after the activation of the embryonic genome, the embryo begins to metabolize glucose more efficiently, especially due to the greater activity of the glycolytic pathway. Through it, the produced pyruvate is directed to the mitochondria, converted to acetyl-CoA, entering the cycle of tricarboxilic acid. One of the metabolites generated in this cycle is citrate, which can be converted to acetyl-CoA again in the cytoplasm and serve as a precursor for the acetylation of histones, modifying the overall gene transcription pattern of the cell. The hypothesis of this work is that the pharmacological modulation of the glycolytic pathway in bovine embryos produced in vitro can lead to different profiles of citrate and acetyl-CoA generation, interfering with the histone acetylation pattern, thus altering its metabolic profile and potency of the blastocyst cells. For this, it is proposed to promote the modulation of the glycolytic pathway in bovine IVP embryos with an inhibitor of the enzyme glyceraldehyde-3-phosphate dehydrogenase (G3PD), sodium iodoacetate (IA), as well as an inhibitor of phosphorylation of the enzyme pyruvate dehydrogenase (PDH), sodium dichloroacetate (DCA) from the time of major activation of the embryonic genome (stage of 8 to 16 cells). In these models, the production/consumption of lactate, glucose, pyruvate, citrate, ATP/ADP, NADH and Acetyl-CoA in the culture medium will be verified; in the embryos, phosphorylated PDK, ACL, HAT and phosphorylated GAPDH proteins and the presence of glycolytic pathway transcripts, mitochondrial function, cell potential. (AU)