Association between amino acid turnover and chromosome aneuploidy during human preimplantation embryo development in vitro

Abstract

This study investigated the relationship between human preimplantation embryo metabolism and aneuploidy rates during development in vitro. One hundred and eighty-eight fresh and cryopreserved embryos from 59 patients (33.9 +/- 0.6 years) were cultured for 2-5 days. The turnover of 18 amino acids was measured in spent media by high-performance liquid chromatography. Embryos were either fixed for interphase fluorescent in situ hybridization analysis of chromosomes 13, 18, 19, 21, X or Y, or were assayed for mitochondrial activity. Amino acid turnover was different (P < 0.05) between stage-matched fresh and cryopreserved embryos due to blastomere loss following warming. The proportion of embryos with aneuploid cells increased as cell division progressed from pronucleate- (23%) to late cleavage stages (50-70%). Asparagine, glycine and valine turnover was significantly different between uniformly genetically normal and uniformly abnormal embryos on Days 2-3 of culture. By Days 3-4, the profiles of serine, leucine and lysine differed between uniformly euploid versus aneuploid embryos. Gender significantly (P < 0.05) affected the metabolism of tryptophan, leucine and asparagine by cleavage-stage embryos. Pronucleate zygotes had a significantly higher proportion of active:inactive mitochondria compared with cleavage-stage embryos. Furthermore, mitochondrial activity was correlated (P < 0.05) with altered aspartate and glutamine turnover. These results demonstrate the association between the metabolism, cytogenetic composition and health of human embryos in vitro.

Astaxanthin ameliorates heat stress-induced impairment of blastocyst development In Vitro: –astaxanthin colocalization with and action on mitochondria–

“…As in the present study, physiological, environmental, or clinical factors can decrease ΔΨm in human oocytes and early embryos, which is one of proposed causes of their compromised quality and IVF outcome. These factors include advanced age of women [34,52], clinical hyperstimulation protocol [8], cryopreservation [20], and the condition of in vitro culture [53]. Therefore, Δ<m-promoting effects of Ax in challenged conditions shown in the present study may be applicable for ameliorating the effects of deleterious factors involved in human IVF.…”

Metabolism throughout follicle and oocyte development in mammals

“…Metabolic studies -which initially used radiolabelled substrates-made it possible to define the and is providing insights into the amino acids utilized by healthy oocytes (Hemmings et al, 2012). Indeed, in pre-implantation embryos the quantification of amino acid and energy metabolism is emerging as a potential non-invasive tool with which to assess embryo developmental competence and even pregnancy outcome Picton et al, 2010;Gardner et al, 2011).…”

Zygote serine decreased uptake from the fertilization medium is associated with implantation and pregnancy

“…Studies on pyruvate metabolism showed that increased uptake is correlated with embryo development, but the overall results were inconsistent [24-27, 11, 3, 28]. Glucose consumption was associated with blastocyst development [10]; however, other reports failed to demonstrate this relationship [27,11,29]. Studies regarding oxygen as a metabolite in the oocytes' fertilization environment, found an association between oxygen consumption embryonic development and implantation [13].…”