title: Na-butyrate sustains energetic states of metabolism and t-PA productivity of CHO cells.
abstract: The effects of Na-butyrate on the physiological behaviour and on the specific productivity of recombinant tissue plasminogen activator (t-PA) Chinese Hamster Ovary (CHO) cells were characterized. Batch cultures were performed in a 3.5-L bioreactor. Na-butyrate was added either at the mid-exponential growth phase (48 h) or at the end of the exponential growth phase (74 h). The cultures with Na-butyrate showed higher net specific productivity of t-PA and lower final cell density and viability. Maximum specific productivity of t-PA for all cultures coincided with the early plateau phase (84 h). The cell's specific oxygen uptake rate (qO2) increased after the Na-butyrate addition and remained higher than that of the controlled culture. Triphosphate nucleotides, ADP, AMP and UDP-sugars all increased after 84 h in the cultures with Na-butyrate, showing different behaviours when Na-butyrate was added at 48 h or 74 h. Na-butyrate did not affect the cell's adenylate energy charge until the cell's viability started to decrease (156-168 h). The controlled culture and the culture with Na-butyrate addition, showed at 74 h, similar time trends as for purine and nucleotide ratios ((ATP+GTP)/(UTP+CTP) and UTP/ATP) with clear shifts in behaviour at 84 h and 168 h. However, the addition of Na-butyrate at 48 h resulted in damped variations of purine and nucleotide ratios in comparison to both the control culture and the culture with Na-butyrate addition at 74 h.
authors.affiliation: Canada Research Chair in Applied Metabolic Engineering, Ecole Polytechnique de Montréal, P.O. Box 6079, Centre-ville Station, Montréal, Québec H3C3A7, Canada.
authors.forename: Virginie
authors.initials: V
authors.lastname: McMurray-Beaulieu
authors.forename: Steve
authors.initials: S
authors.lastname: Hisiger
authors.forename: Caroline
authors.initials: C
authors.lastname: Durand
authors.forename: Michel
authors.initials: M
authors.lastname: Perrier
authors.forename: Mario
authors.initials: M
authors.lastname: Jolicoeur
mesh_terms: D000818:Animals; D002087:Butyrates / Q000494:pharmacology*; D016466:CHO Cells; D018929:Cell Culture Techniques; D006224:Cricetinae; D003412:Cricetulus; D004734:Energy Metabolism / Q000187:drug effects*; D006801:Humans; D009711:Nucleotides / Q000378:metabolism; D011994:Recombinant Proteins / Q000096:biosynthesis*; D013997:Time Factors; D010959:Tissue Plasminogen Activator / Q000096:biosynthesis*
chemical_list: D002087:Butyrates; D009711:Nucleotides; D011994:Recombinant Proteins; D010959:Tissue Plasminogen Activator