Reactive oxygen species (ROS) act as cellular signaling molecules involved in the propagation of signaling and the translation of environmental cues into cellular responses to maintain cellular homeostasis, which is mediated by the coordination of various cellular processes, and to adapt cellular activity to available bioenergetic sources.
ROS are more reactive than free oxygen and are well known for their critical roles in the regulation of the developmental processes, such as the emergence of embryonic blood stem cells or differentiation of embryonic cardiomyocytes. ROS are also involved in many bio- logical processes including gene transcription, protein translation, and protein-protein interactions.
Recent advances in physiological relevance between oxygen and stem cells have revealed that oxygen acts as an important signaling molecule as well as a critical factor in the stem cell niche. New findings strongly indicate that ROS have important roles in both stem cell maintenance and their differentiation, which provide the possibility that the regulation of ROS in stem cells could be a valuable tool for developing stem cell-based therapeutics.
ROS act as signaling mediators linking between metabolic alteration and stem cell fate. Therefore, the elucidation of ROS regulation on stem cell proliferation and maintenance of self-renewal capacity will provide new insight into the optimization of in vitro stem cell culture systems, embryonic development, and the regulation of stem cell fate for therapeutic applications of stem cells. For a detailed review on the argument, read Min Ryu et al., 2015 (https://www.ncbi.nlm.nih.gov/pubmed/26019752).