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Impact of sodium butyrate and mild hypothermia on metabolic and physiological behaviour of CHO TF 70R cells
Avello, Veronica; Tapia, Bethzabeth; Vergara, Mauricio; Acevedo, Cristian; Berrios, Julio; Reyes, Juan G. & Altamirano, Claudia
Abstract
Background: To reduce costs associated with productivity of recombinant proteins in the biopharmaceutical
industry, research has been focused on regulatory principals of growth and survival during the production
phases of the cell culture. The main strategies involve the regulation of cell proliferation by the modulation of
cell cycle control points (G1/S or G2/M) with mild hypothermia and the addition of sodium butyrate (NaBu).
In this study, batch culture strategies were evaluated using CHO TF 70R cells producing the recombinant
human tissue plasminogen activator (rh-tPA), to observe their individual and combined effect on the cellular
physiological state and relevant kinetic parameters.
Results: NaBu addition has a negative effect on the mitochondrial membrane potential (ΔΨm), the values of
which are remarkably diminished in cultures exposed to this cytotoxic compound. This effect was not
reflected in a loss of cell viability. NaBu and mild hypothermic conditions increased the doubling time in the
cell cultures, suggesting that these strategies triggered a general slowing of each cell cycle phase in a different
way. Finally, the individual and combined effect of NaBu and mild hypothermia produced an increase in the
specific rh-tPA productivity in comparison to the control at 37°C without NaBu. Nevertheless, both strategies
did not have a synergistic effect on the specific productivity.
Conclusions: The combination of NaBu addition and mild hypothermic condition causes an impact on
physiological and metabolic state of CHO TF 70R cells, decreasing cell growth rate and improving glucose
consumption efficiency. These results therefore provide a promising strategy to increase specific productivity
of rh-tPA.
Keywords
Cell cycle modulation; Cell viability; Chinese hamster ovary; Combined effect; Cytotoxic; Mitochondrial membrane potential; Recombinant human tissue plasminogen activator; Recombinant proteins; Regulation of cell proliferation; rh-tPA production; Sodium butyrate
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