Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), 20 Biopolis Way, #06-01, Centros, Singapore 138668, Singapore.
Biotechnol Bioeng. 2012 Jun;109(6):1415-29. doi: 10.1002/bit.24445. Epub 2012 Jan 31.
The increasing demand for recombinant therapeutic proteins highlights the need to constantly improve the efficiency and yield of these biopharmaceutical products from mammalian cells, which is fully achievable only through proper understanding of cellular functioning. Towards this end, the current study exploited a combined metabolomics and in silico modeling approach to gain a deeper insight into the cellular mechanisms of Chinese hamster ovary (CHO) fed-batch cultures. Initially, extracellular and intracellular metabolite profiling analysis shortlisted key metabolites associated with cell growth limitation within the energy, glutathione, and glycerophospholipid pathways that have distinct changes at the exponential-stationary transition phase of the cultures. In addition, biomass compositional analysis newly revealed different amino acid content in the CHO cells from other mammalian cells, indicating the significance of accurate protein composition data in metabolite balancing across required nutrient assimilation, metabolic utilization, and cell growth. Subsequent in silico modeling of CHO cells characterized internal metabolic behaviors attaining physiological changes during growth and non-growth phases, thereby allowing us to explore relevant pathways to growth limitation and identify major growth-limiting factors including the oxidative stress and depletion of lipid metabolites. Such key information on growth-related mechanisms derived from the current approach can potentially guide the development of new strategies to enhance CHO culture performance.
不断增长的对重组治疗性蛋白的需求凸显了从哺乳动物细胞中持续提高这些生物制药产品的效率和产量的必要性，而这只有通过对细胞功能的正确理解才能完全实现。为此，本研究采用了代谢组学和计算建模相结合的方法，深入了解中国仓鼠卵巢（CHO）分批补料培养中的细胞机制。最初，细胞外和细胞内代谢产物谱分析将与能量、谷胱甘肽和甘油磷脂代谢途径中细胞生长受限相关的关键代谢物进行了分类，这些代谢物在培养物的指数-稳定过渡阶段有明显变化。此外，生物量组成分析还揭示了 CHO 细胞与其他哺乳动物细胞在氨基酸含量上的不同，这表明在必需营养物质同化、代谢利用和细胞生长过程中，准确的蛋白质组成数据对于代谢物平衡具有重要意义。随后对 CHO 细胞进行的计算建模描述了内部代谢行为，在生长和非生长阶段实现了生理变化，从而使我们能够探索与生长受限相关的途径，并确定主要的生长限制因素，包括氧化应激和脂质代谢物的消耗。从当前方法中获得的与生长相关的机制的关键信息，可能有助于指导开发提高 CHO 培养性能的新策略。
