Effect of oxygen tension on the amino acid utilisation of human embryonic stem cells.
OBJECTIVE
Human embryonic stem cells (hESCs) are a potential source of cells for treatment of many degenerative diseases, but in culture have a propensity to spontaneously differentiate, possibly due to suboptimal conditions. Culture at low oxygen tensions improves hESC maintenance and regulates carbohydrate metabolism. Hence, a greater understanding of the nutrient requirements of hESCs will allow production of more appropriate culture media. This study aims to investigate the effect of environmental oxygen tension on the amino acid metabolism of hESCs.


METHODS
The production or depletion of amino acids by hESCs cultured at 5% or 20% oxygen in the presence or absence of FGF2 was measured by reversephase HPLC.


RESULTS
Atmospheric oxygen, or removal of FGF2 from hESCs cultured at 5% oxygen, perturbed the uptake or release of individual amino acids and the total amino acid turnover compared to hESCs cultured at 5% oxygen. In particular, serine uptake was reduced at 20% oxygen and by removal of FGF2.


CONCLUSIONS
Highly pluripotent hESCs, cultured at 5% oxygen, demonstrate a greater amino acid turnover than hESCs cultured at 20% oxygen, or without FGF2. These data suggest that amino acid turnover could be used as a measure of the self-renewal capacity of hESCs.
Centre for Human Development, Stem Cells & Regeneration, University of Southampton, Southampton, UK.
David R
DR
Christensen
Philip C
PC
Calder
Franchesca D
FD
Houghton
D000596:Amino Acids / Q000378:metabolism*; D002478:Cells, Cultured; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D000066449:Human Embryonic Stem Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D055442:Metabolome / Q000187:drug effects; D010100:Oxygen / Q000494:pharmacology*; D013997:Time Factors
D000596:Amino Acids; D016222:Fibroblast Growth Factor 2; D010100:Oxygen