Nox4-IGF2 axis promotes differentiation of embryoid body cells into derivatives of the three embryonic germ layers

Reactive oxygen species (ROS) play important roles as second messengers in a wide array of cellular processes including differentiation of stem cells. We identified Nox4 as the major ROS generating enzyme whose expression is induced during differentiation of embryoid body (EB) into cells of all three germ layers. The role of Nox4 was examined using iPS cells generated from Nox4 -/- mouse. Differentiation markers showed significantly reduced expression levels consistent with the importance of Nox4-generated ROS during this process. From transcriptomic analyses, we found insulin-like growth factor 2 (IGF2), a member of a gene family extensively involved in embryonic development, as one of the most down-regulated genes. Indeed, addition of IGF2 to culture partly restored the differentiation efficiency of Nox4-/- iPS cells. Our results reveal an important signaling axis mediated by ROS in control of crucial events during differentiation of pluripotent stem cells. Time-series mRNA profiles of wild type (WT) and Nox4 knockout iPSC