Stem cells generally occupy low oxygen niches. Historically, cultivation of stem cells is usually performed at 20% oxygen, which is aphysiologically toxic and induces oxidant stress. Stem cells cultured at physiologic (3-6%) vs. 20% oxygen display extremely different expression profiles and behaviors. Reactive oxygen species (ROS) levels are tightly regulated and play ubiquitous roles in signaling; high ROS levels lead to dysregulation of all cellular processes. This session will review ROS signaling in normal hematopoiesis and homeostasis and hematopoietic malignancies and discuss quantitative imaging of the marrow oxygen environment. It will also examine expression patterns and phenotypes of retinal stem cells at physiologic vs. 20% oxygen. A speaker will describe how oxygen conditions for clinical-scale expansions of multipotent adult progenitor cells are determined. This session will describe the importance of oxygen and oxidant stress signaling at multiple scales—biochemical, imaging, cellular, and clinical manufacturing.


Saghi Ghaffari and Tony Ting did not give consent to be recorded.