Figure 3. Diagram of the involvement of ROS in signaling cascades resulting in cardiovascular commitment of ES cells. ROS are generated through the activity of a presumably membrane-bound NADPH oxidase that is up-regulated following mechanical strain application. ROS initiate phosphorylation of the MAPKs ERK1,2, JNK and p38. Vasculogenesis/angiogenesis requires the activation of ERK1,2 and JNK, whereas the activity of ERK1,2, JNK and p38 is necessary for cardiomyogenesis.