The Effects Of Low Oxygen On Differentiation Of Mouse Embryonic Stem Cells Into Cardiomyocytes

Objective To explore the effects of low oxygen at different stages ondifferentiation of mouse embryonic stem cells into cardiomyocytes.Method The way to induce embryonic stem cells into cardiomyocytes wasestablished. At the different stages of differentiation, low oxygen (4%) or normaloxygen (20%） was used. Differentiated cardiomyocytes were identified byimmunofluorescence. The effects of low oxygen on cell proliferation, differentiation,and apoptosis of differentiated cardiomyocytes were measured.Results Immunofluorescence staining showed that part of differentiatedcardiomyocytes were α-actinin positive (red）and cTnI positive (green). Compared withthe normoxic group, flow cytometry results showed that α-actinin positive cellsincreased by12.55%(p <0.01**) and cTnI positive cells increased by6.11%(p <0.05*)in the hanging-drop group of low oxygen. Compared with normoxic group, theproportion of apoptotic cells significantly increased (p <0.01**) in the suspension groupof low oxygen. Compared with normoxic group, the proportion of cells in S phasesignificantly decreased (p <0.01**) in the hanging-drop group of low oxygen.Conclusion In the phase of amplification and hanging-drop, low oxygenenhances cardiac differentiation of embryonic stem cells, especially in the phase ofhanging-drop; While in the suspension period, low oxygen is unfavorable todifferentiation of embryonic stem cells into cardiomyocytes.