Oxygen concentration regulates 5-azacytidine-induced myogenesis in C3H/10T1/2 cultures.
This study reports that changing the oxygen concentration within a physiologic range has a striking effect on myogenesis induced by the cytidine analog 5-azacytidine. Reducing oxygen from 20% to 2.5% increases 7-fold the number of myocytes that appear in cultures of C3H/10T1/2 mouse embryo cells 10 days after they receive a 24-h exposure to 5-azacytidine. Reducing oxygen does not alter the extent to which a 24-h exposure to 5-azacytidine inhibits cytosine methylation in newly synthesized DNA. Instead, the oxygen-sensitive step in myogenesis occurs after 5-azacytidine is removed from the culture medium. Reducing oxygen increases the rate of logarithmic growth in C3H/10T1/2 cultures after 5-azacytidine exposure, suggesting that survival and proliferation of myocyte stem cells (morphologically indistinguishable from uncommitted C3H/10T1/2 cells) may be the oxygen-sensitive steps in myogenesis.
Storch
T G
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Department of Pediatrics, Tulane University School of Medicine, New Orleans, LA 70112.
D044503:5-Methylcytosine; D000818:Animals; D001374:Azacitidine / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D003596:Cytosine / Q000031:analogs & derivatives / Q000032:analysis; D004247:DNA / Q000378:metabolism; D007700:Kinetics; D008745:Methylation; D051379:Mice; D008809:Mice, Inbred C3H; D009132:Muscles / Q000166:cytology* / Q000187:drug effects; D010100:Oxygen / Q000494:pharmacology*
D044503:5-Methylcytosine; D003596:Cytosine; D004247:DNA; D001374:Azacitidine; D010100:Oxygen