New insights into human pre-implantation metabolism in vivo and in vitro

• Published in: Journal of assisted reproduction and genetics 2013-03, Vol.30 (3), p.293-303
• Main Authors: Ménézo, Yves, Lichtblau, Isabelle, Elder, Kay
• Format: Article
• Language: English
• Subjects: Amino acids; Amino Acids - metabolism; Apoptosis; Biochemistry; Cell cycle; Cell division; Chromosomes; DNA methylation; Embryonic Development - physiology; Embryos; Fertilization in Vitro; Genomes; Genomic Imprinting - genetics; Genomic Imprinting - physiology; Gynecology; Human Genetics; Humans; Lipid Metabolism - physiology; Lipids; Medicine; Medicine & Public Health; Metabolism; Metabolism - genetics; Metabolism - physiology; Metabolites; Oxidative stress; Oxidative Stress - physiology; Physiology; Reproductive Medicine; Review; Vitamins - metabolism
• ISSN: 1058-0468; 1573-7330
• DOI: 10.1007/s10815-013-9953-9

The metabolism of pre-implantation embryos is far from being understood. In human embryos, the two major obstacles are the scarcity of material, for obvious ethical reasons, and complete absence of a relevant in vivo control model. Over-extrapolation from animal species to human systems adds to the complexity of the problem. Removal of some metabolites from media has been proposed, such as glucose and essential amino acids, on the basis of their pseudo “toxicity”. In contrast, addition of some compounds such as growth factors has been proposed in order to decrease apoptosis, which is a natural physiologic process. These suggestions reflect the absence of global knowledge, and in consequence mask reality. Some aspects of metabolism have been ignored, such as lipid metabolism. Others are seriously underestimated, such as oxidative stress and its relationship to imprinting/methylation, of paramount importance for genetic regulation and chromosomal stability. It has become increasingly obvious that more studies are essential, especially in view of the major extension of ART activities worldwide.