Combining lipoic acid to methylene blue reduces the Warburg effect in CHO cells: From TCA cycle activation to enhancing monoclonal antibody production

PLoS One. 2020 Apr 16;15(4):e0231770. doi: 10.1371/journal.pone.0231770. eCollection 2020.

Abstract

The Warburg effect, a hallmark of cancer, has recently been identified as a metabolic limitation of Chinese Hamster Ovary (CHO) cells, the primary platform for the production of monoclonal antibodies (mAb). Metabolic engineering approaches, including genetic modifications and feeding strategies, have been attempted to impose the metabolic prevalence of respiration over aerobic glycolysis. Their main objective lies in decreasing lactate production while improving energy efficiency. Although yielding promising increases in productivity, such strategies require long development phases and alter entangled metabolic pathways which singular roles remain unclear. We propose to apply drugs used for the metabolic therapy of cancer to target the Warburg effect at different levels, on CHO cells. The use of α-lipoic acid, a pyruvate dehydrogenase activator, replenished the Krebs cycle through increased anaplerosis but resulted in mitochondrial saturation. The electron shuttle function of a second drug, methylene blue, enhanced the mitochondrial capacity. It pulled on anaplerotic pathways while reducing stress signals and resulted in a 24% increase of the maximum mAb production. Finally, the combination of both drugs proved to be promising for stimulating Krebs cycle activity and mitochondrial respiration. Therefore, drugs used in metabolic therapy are valuable candidates to understand and improve the metabolic limitations of CHO-based bioproduction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Monoclonal / biosynthesis*
  • CHO Cells
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects
  • Citric Acid Cycle / physiology*
  • Cricetulus
  • Glucose / metabolism
  • Glutamine / metabolism
  • Glycolysis / drug effects*
  • Glycolysis / physiology
  • Lactic Acid / metabolism
  • Membrane Potential, Mitochondrial / drug effects
  • Metabolic Engineering / methods*
  • Methylene Blue / metabolism
  • Methylene Blue / pharmacology*
  • Mitochondria / drug effects
  • Mitochondria / metabolism
  • Oxidative Phosphorylation / drug effects
  • Oxidative Stress / drug effects
  • Respiration
  • Thioctic Acid / metabolism
  • Thioctic Acid / pharmacology*

Substances

  • Antibodies, Monoclonal
  • Glutamine
  • Lactic Acid
  • Thioctic Acid
  • Glucose
  • Methylene Blue

Grant support

MJ received the NSERC (https://www.nserc-crsng.gc.ca/) Discovery Grant #RGPIN-2019-05050. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.