title: Effect of oxygen tension on bioenergetics and proteostasis in young and old myoblast precursor cells.
abstract: In the majority of studies using primary cultures of myoblasts, the cells are maintained at ambient oxygen tension (21% O2), despite the fact that physiological O2 at the tissue level in vivo is much lower (~1-5% O2). We hypothesized that the cellular response in presence of high oxygen concentration might be particularly important in studies comparing energetic function or oxidative stress in cells isolated from young versus old animals. To test this, we asked whether oxygen tension plays a role in mitochondrial bioenergetics (oxygen consumption, glycolysis and fatty acid oxidation) or oxidative damage to proteins (protein disulfides, carbonyls and aggregates) in myoblast precursor cells (MPCs) isolated from young (3-4 m) and old (29-30 m) C57BL/6 mice. MPCs were grown under physiological (3%) or ambient (21%) O2 for two weeks prior to exposure to an acute oxidative insult (H2O2). Our results show significantly higher basal mitochondrial respiration in young versus old MPCs, an increase in basal respiration in young MPCs maintained at 3% O2 compared to cells maintained at 21% O2, and a shift toward glycolytic metabolism in old MPCs grown at 21% O2. H2O2 treatment significantly reduced respiration in old MPCs grown at 3% O2 but did not further repress respiration at 21% O2 in old MPCs. Oxidative damage to protein was higher in cells maintained at 21% O2 and increased in response to H2O2 in old MPCs. These data underscore the importance of understanding the effect of ambient oxygen tension in cell culture studies, in particular studies measuring oxidative damage and mitochondrial function.
authors.affiliation: Barshop Institute for Longevity and Aging Studies, The University of Texas Health Science Center, San Antonio, TX 78229, USA ; Universidad Autonoma Metropolitana-Iztapalpa, Mexico City, Mexico.
authors.forename: M
authors.initials: M
authors.lastname: Konigsberg
authors.forename: V I
authors.initials: VI
authors.lastname: Pérez
authors.forename: C
authors.initials: C
authors.lastname: Ríos
authors.forename: Y
authors.initials: Y
authors.lastname: Liu
authors.forename: S
authors.initials: S
authors.lastname: Lee
authors.forename: Y
authors.initials: Y
authors.lastname: Shi
authors.forename: H
authors.initials: H
authors.lastname: Van Remmen
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques; D049109:Cell Proliferation; D002478:Cells, Cultured; D004734:Energy Metabolism / Q000187:drug effects*; D006614:Hindlimb / Q000166:cytology; D006861:Hydrogen Peroxide / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008928:Mitochondria / Q000187:drug effects / Q000502:physiology; D018482:Muscle, Skeletal / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D013997:Time Factors
chemical_list: D006861:Hydrogen Peroxide; D010100:Oxygen
keywords: Hypoxia; Mitochondrial respiration; Myoblasts; Oxidative stress; Protein damage