Role of Blood Oxygen Saturation During Post-Natal Human Cardiomyocyte Cell Cycle Activities

Summary Blood oxygen saturation (SaO2) is one of the most important environmental factors in clinical heart protection. This study used human heart samples and human induced pluripotent stem cell−cardiomyocytes (iPSC-CMs) to assess how SaO2 affects human CM cell cycle activities. The results showed that there were significantly more cell cycle markers in the moderate hypoxia group (SaO2: 75% to 85%) than in the other 2 groups (SaO2  85%). In iPSC-CMs 15% and 10% oxygen (O2) treatment increased cell cycle markers, whereas 5% and rapid change of O2 decreased the markers. Moderate hypoxia is beneficial to the cell cycle activities of post-natal human CMs.