title: An omics approach to rational feed: Enhancing growth in CHO cultures with NMR metabolomics and 2D-DIGE proteomics.
abstract: Expression of recombinant proteins exerts stress on cell culture systems, affecting the expression of endogenous proteins, and contributing to the depletion of nutrients and accumulation of waste metabolites. In this work, 2D-DIGE proteomics was employed to analyze differential expression of proteins following stable transfection of a Chinese Hamster Ovary (CHO) cell line to constitutively express a heavy-chain monoclonal antibody. Thirty-four proteins of significant differential expression were identified and cross-referenced with cellular functions and metabolic pathways to identify points of cell stress. Subsequently, 1D-(1)H NMR metabolomics experiments analyzed cultures to observe nutrient depletion and waste metabolite accumulations to further examine these cell stresses and pathways. From among fifty metabolites tracked in time-course, eight were observed to be completely depleted from the production media, including: glucose, glutamine, proline, serine, cystine, asparagine, choline, and hypoxanthine, while twenty-three excreted metabolites were also observed to accumulate. The differentially expressed proteins, as well as the nutrient depletion and accumulation of these metabolites corresponded with upregulated pathways and cell systems related to anaplerotic TCA-replenishment, NADH/NADPH replenishment, tetrahydrofolate cycle C1 cofactor conversions, limitations to lipid synthesis, and redox modulation. A nutrient cocktail was assembled to improve the growth medium and alleviate these cell stresses to achieve a ∼75% improvement to peak cell densities.
authors: Waterloo Institute for Nanotechnology, Department of Chemical Engineering, University of Waterloo, Waterloo, Ontario, Canada.
authors: Eric J M
authors: EJM
authors: Blondeel
authors: Department of Biology, University of Waterloo, Waterloo, Ontario, Canada.
authors: Raymond
authors: R
authors: Ho
authors: Waterloo Institute for Nanotechnology, Department of Chemical Engineering, University of Waterloo, Waterloo, Ontario, Canada; Institute of Applied Biotechnology, University of Applied Sciences Biberach, Biberach, Germany.
authors: Steffen
authors: S
authors: Schulze
authors: Waterloo Institute for Nanotechnology, Department of Chemical Engineering, University of Waterloo, Waterloo, Ontario, Canada.
authors: Stanislav
authors: S
authors: Sokolenko
authors: Waterloo Institute for Nanotechnology, Department of Chemical Engineering, University of Waterloo, Waterloo, Ontario, Canada.
authors: Simon R
authors: SR
authors: Guillemette
authors: Biotechnology Research Institute, National Research Council of Canada, Montreal, QC, Canada.
authors: Igor
authors: I
authors: Slivac
authors: Biotechnology Research Institute, National Research Council of Canada, Montreal, QC, Canada.
authors: Yves
authors: Y
authors: Durocher
authors: Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada.
authors: J Guy
authors: JG
authors: Guillemette
authors: Department of Biology, University of Waterloo, Waterloo, Ontario, Canada.
authors: Brendan J
authors: BJ
authors: McConkey
authors: Chenomx Inc., Edmonton, Alberta, Canada.
authors: David
authors: D
authors: Chang
authors: Waterloo Institute for Nanotechnology, Department of Chemical Engineering, University of Waterloo, Waterloo, Ontario, Canada. Electronic address: marc.aucoin@uwaterloo.ca.
authors: Marc G
authors: MG
authors: Aucoin
mesh_terms: D000818:Animals; D016466:CHO Cells; D018929:Cell Culture Techniques; D006224:Cricetinae; D003412:Cricetulus; D003470:Culture Media; D006801:Humans; D007525:Isoelectric Focusing; D009682:Magnetic Resonance Spectroscopy; D053858:Metabolic Networks and Pathways; D055432:Metabolomics / Q000379:methods*; D040901:Proteomics / Q000379:methods*; D011994:Recombinant Proteins / Q000032:analysis* / Q000096:biosynthesis* / Q000378:metabolism*; D053719:Tandem Mass Spectrometry; D057825:Two-Dimensional Difference Gel Electrophoresis
chemical_list: D003470:Culture Media; D011994:Recombinant Proteins
keywords: 2D-DIGE; CHO cells; Metabolomics; NMR; Proteomics