Re-programming CHO cell metabolism using miR-23 tips the balance towards a highly productive phenotype

Area of Science:

• Biotechnology
• Cell Biology
• Metabolic Engineering

Background:

• microRNA (miRNA) engineering in Chinese hamster ovary (CHO) cells enhances phenotypes and recombinant product yield.
• miRNAs regulate multiple mRNA targets, influencing cellular metabolism and phenotypes like growth and productivity.
• miR-23 is implicated in glutamate metabolism and oxidative phosphorylation via the TCA cycle.

Purpose of the Study:

• To investigate the potential of reprogramming cellular bioenergetics through miR-23 manipulation for enhanced mammalian cell culture productivity.
• To determine the effect of miR-23 depletion on CHO cell specific productivity and growth.
• To elucidate the impact of miR-23 on mitochondrial activity and identify its novel targets.

Main Methods:

• Engineering CHO cell clones using a miR-sponge decoy to deplete miR-23.
• Measuring specific productivity and cell growth rates.
• Utilizing cell respirometry to assess mitochondrial activity at the electron transport system (Complex I and II).
• Performing label-free proteomic analysis to identify miR-23 targets.

Main Results:

• CHO clones depleted of miR-23 exhibited an average threefold increase in specific productivity without affecting cell growth.
• Mitochondrial activity, specifically at Complex I and II of the electron transport system, was enhanced by approximately 30%.
• Proteomic analysis identified potential novel miR-23 targets, including LE1 and IDH1, involved in oxidative metabolism.

Conclusions:

• miRNA-based engineering is a viable strategy for reprogramming cellular metabolism in CHO cells.
• miR-23 depletion enhances mitochondrial oxidative metabolism, leading to significantly increased productivity.
• This approach offers a method to boost biopharmaceutical production without compromising cell growth viability.