Supraphysiological Oxygen Levels in Mammalian Cell Culture: Current State and Future Perspectives

• Published in: Cells (Basel, Switzerland) Vol. 11; no. 19; p. 3123
• Main Authors: Alva, Ricardo, Gardner, Georgina L, Liang, Ping, Stuart, Jeffrey A
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01.10.2022; MDPI
• Subjects: Analysis; Animals; Biomarkers; Cell culture; Cell Culture Techniques; Enzymes; Fibroblasts; Gene expression; Headspace; Health aspects; Homeostasis; Hormones; Humans; Hyperoxia; Hypoxia; Incubators (Pediatrics); Life span; Lipid peroxidation; Lipids; Mammals - metabolism; Metabolism; Mitochondria; Oxidation; oxidative stress; oxygen; Oxygen - metabolism; Physiology; Physiology, Pathological; physioxia; Proteins; Reactive oxygen species; Reactive Oxygen Species - metabolism; Review; ROS; Sea level; Stem cells; Toxicants; Canada; drug response; senescence; hyperoxia; ROS; metabolism; oxygen; gene expression; oxidative stress; physioxia; mitochondrial dynamics
• ISSN: 2073-4409; 2073-4409
• DOI: 10.3390/cells11193123

Most conventional incubators used in cell culture do not regulate O levels, making the headspace O concentration ~18%. In contrast, most human tissues are exposed to 2-6% O (physioxia) in vivo. Accumulating evidence has shown that such hyperoxic conditions in standard cell culture practices affect a variety of biological processes. In this review, we discuss how supraphysiological O levels affect reactive oxygen species (ROS) metabolism and redox homeostasis, gene expression, replicative lifespan, cellular respiration, and mitochondrial dynamics. Furthermore, we present evidence demonstrating how hyperoxic cell culture conditions fail to recapitulate the physiological and pathological behavior of tissues in vivo, including cases of how O alters the cellular response to drugs, hormones, and toxicants. We conclude that maintaining physioxia in cell culture is imperative in order to better replicate in vivo-like tissue physiology and pathology, and to avoid artifacts in research involving cell culture.