Department of Tissue Regeneration, University of Twente, Enschede, The Netherlands.
Tissue Eng Part A. 2012 Mar;18(5-6):654-64. doi: 10.1089/ten.TEA.2011.0223. Epub 2011 Nov 21.
The nutritional requirements of stem cells have not been determined; in particular, the amino acid metabolism of stem cells is largely unknown. In this study, we investigated the amino acid metabolism of human mesenchymal stem cells (hMSCs), with focus on two questions: Which amino acids are consumed and/or secreted by hMSCs and at what rates? To answer these questions, hMSCs were cultured on tissue culture plastic and in a bioreactor, and their amino acid profile was analyzed. The results showed that the kinetics of hMSCs growth and amino acid metabolism were significantly higher for hMSCs in tissue culture plastic than in the bioreactor. Despite differences in culture conditions, 8 essential and 6 nonessential amino acids were consumed by hMSCs in both tissue culture plastic and bioreactor cultures. Glutamine was the most consumed amino acid with significantly higher rates than for any other amino acid. The metabolism of nonessential amino acids by hMSCs deviated significantly from that of other cell lines. The secretion of alanine, glycine, glutamate, and ornithine by hMSCs showed that there is a strong overflow metabolism that can be due to the high concentrations of amino acids provided in the medium. In addition, the data showed that there is a metabolic pattern for proliferating hMSCs, which can contribute to the design of medium without animal serum for stem cells. Further, this study shows how to implement amino acid rates and metabolic principles in three-dimensional stem cell biology.
干细胞的营养需求尚未确定；特别是，干细胞的氨基酸代谢在很大程度上是未知的。在这项研究中，我们研究了人骨髓间充质干细胞（hMSC）的氨基酸代谢，重点关注两个问题：hMSC 消耗和/或分泌哪些氨基酸以及以什么速率消耗和/或分泌？为了回答这些问题，我们将 hMSC 培养在组织培养塑料和生物反应器中，并分析其氨基酸谱。结果表明，hMSC 在组织培养塑料中的生长和氨基酸代谢动力学明显高于生物反应器。尽管培养条件存在差异，但 hMSC 在组织培养塑料和生物反应器培养中都消耗了 8 种必需氨基酸和 6 种非必需氨基酸。谷氨酰胺是消耗最多的氨基酸，其消耗速率明显高于其他任何氨基酸。hMSC 中非必需氨基酸的代谢与其他细胞系有明显的差异。hMSC 分泌的丙氨酸、甘氨酸、谷氨酸和鸟氨酸表明存在强烈的溢出代谢，这可能是由于培养基中提供的氨基酸浓度很高。此外，数据表明，增殖的 hMSC 存在一种代谢模式，这有助于为无动物血清的干细胞设计培养基。此外，这项研究展示了如何在三维干细胞生物学中实施氨基酸速率和代谢原则。
