Atmospheric oxygen tension slows myoblast proliferation via mitochondrial activation.
Mitochondrial activity inhibits proliferation and is required for differentiation of myoblasts. Myoblast proliferation is also inhibited by the ~20% oxygen level used in standard tissue culture. We hypothesize that mitochondrial activity would be greater at hyperoxia (20% O(2)) relative to more phys...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2012-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC3427224?pdf=render |
| _version_ | 1819010382408187904 |
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| author | Stephanie Duguez William J Duddy Viola Gnocchi James Bowe Sherry Dadgar Terence A Partridge |
| author_facet | Stephanie Duguez William J Duddy Viola Gnocchi James Bowe Sherry Dadgar Terence A Partridge |
| author_sort | Stephanie Duguez |
| collection | DOAJ |
| description | Mitochondrial activity inhibits proliferation and is required for differentiation of myoblasts. Myoblast proliferation is also inhibited by the ~20% oxygen level used in standard tissue culture. We hypothesize that mitochondrial activity would be greater at hyperoxia (20% O(2)) relative to more physiological oxygen (5% O(2)).Murine primary myoblasts from isolated myofibres and conditionally immortalized H-2K myoblasts were cultured at 5% and 20% oxygen. Proliferation, assayed by cell counts, EdU labeling, and CFSE dilution, was slower at 20% oxygen. Expression of MyoD in primary myoblasts was delayed at 20% oxygen, but myogenicity, as measured by fusion index, was slightly higher. FACS-based measurement of mitochondrial activity indicators and luminometric measurement of ATP levels revealed that mitochondria exhibited greater membrane potential and higher levels of Reactive Oxygen Species (ROS) at 20% oxygen with concomitant elevation of intracellular ATP. Mitochondrial mass was unaffected. Low concentrations of CCCP, a respiratory chain uncoupler, and Oligomycin A, an ATP synthase inhibitor, each increased the rate of myoblast proliferation. ROS were investigated as a potential mechanism of mitochondrial retrograde signaling, but scavenging of ROS levels by N-acetyl-cysteine (NAC) or α-Phenyl-N-tert-butylnitrone (PBN) did not rescue the suppressed rate of cell division in hyperoxic conditions, suggesting other pathways. Primary myoblasts from older mice showed a slower proliferation than those from younger adult mice at 20% oxygen but no difference at 5% oxygen.These results implicate mitochondrial regulation as a mechanistic explanation for myoblast response to oxygen tension. The rescue of proliferation rate in myoblasts of aged mice by 5% oxygen suggests a major artefactual component to age-related decline of satellite cell proliferation in standard tissue culture at 20% oxygen. It lends weight to the idea that these age-related changes result at least in part from environmental factors rather than characteristics intrinsic to the satellite cell. |
| first_indexed | 2024-12-21T01:11:22Z |
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| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-21T01:11:22Z |
| publishDate | 2012-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-b088ab8d695b4008919535513b5fb8182022-12-21T19:20:55ZengPublic Library of Science (PLoS)PLoS ONE1932-62032012-01-0178e4385310.1371/journal.pone.0043853Atmospheric oxygen tension slows myoblast proliferation via mitochondrial activation.Stephanie DuguezWilliam J DuddyViola GnocchiJames BoweSherry DadgarTerence A PartridgeMitochondrial activity inhibits proliferation and is required for differentiation of myoblasts. Myoblast proliferation is also inhibited by the ~20% oxygen level used in standard tissue culture. We hypothesize that mitochondrial activity would be greater at hyperoxia (20% O(2)) relative to more physiological oxygen (5% O(2)).Murine primary myoblasts from isolated myofibres and conditionally immortalized H-2K myoblasts were cultured at 5% and 20% oxygen. Proliferation, assayed by cell counts, EdU labeling, and CFSE dilution, was slower at 20% oxygen. Expression of MyoD in primary myoblasts was delayed at 20% oxygen, but myogenicity, as measured by fusion index, was slightly higher. FACS-based measurement of mitochondrial activity indicators and luminometric measurement of ATP levels revealed that mitochondria exhibited greater membrane potential and higher levels of Reactive Oxygen Species (ROS) at 20% oxygen with concomitant elevation of intracellular ATP. Mitochondrial mass was unaffected. Low concentrations of CCCP, a respiratory chain uncoupler, and Oligomycin A, an ATP synthase inhibitor, each increased the rate of myoblast proliferation. ROS were investigated as a potential mechanism of mitochondrial retrograde signaling, but scavenging of ROS levels by N-acetyl-cysteine (NAC) or α-Phenyl-N-tert-butylnitrone (PBN) did not rescue the suppressed rate of cell division in hyperoxic conditions, suggesting other pathways. Primary myoblasts from older mice showed a slower proliferation than those from younger adult mice at 20% oxygen but no difference at 5% oxygen.These results implicate mitochondrial regulation as a mechanistic explanation for myoblast response to oxygen tension. The rescue of proliferation rate in myoblasts of aged mice by 5% oxygen suggests a major artefactual component to age-related decline of satellite cell proliferation in standard tissue culture at 20% oxygen. It lends weight to the idea that these age-related changes result at least in part from environmental factors rather than characteristics intrinsic to the satellite cell.http://europepmc.org/articles/PMC3427224?pdf=render |
| spellingShingle | Stephanie Duguez William J Duddy Viola Gnocchi James Bowe Sherry Dadgar Terence A Partridge Atmospheric oxygen tension slows myoblast proliferation via mitochondrial activation. PLoS ONE |
| title | Atmospheric oxygen tension slows myoblast proliferation via mitochondrial activation. |
| title_full | Atmospheric oxygen tension slows myoblast proliferation via mitochondrial activation. |
| title_fullStr | Atmospheric oxygen tension slows myoblast proliferation via mitochondrial activation. |
| title_full_unstemmed | Atmospheric oxygen tension slows myoblast proliferation via mitochondrial activation. |
| title_short | Atmospheric oxygen tension slows myoblast proliferation via mitochondrial activation. |
| title_sort | atmospheric oxygen tension slows myoblast proliferation via mitochondrial activation |
| url | http://europepmc.org/articles/PMC3427224?pdf=render |
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