Monitoring the induction of ferroptosis following dissociation in human embryonic stem cells.

Human embryonic stem cells (hESCs) are vulnerable to cell death upon dissociation. Thus, dissociation is an obstacle in culturing, maintaining, and differentiating of hESCs. To date, apoptosis has become the focus of research into the nature of cell death triggered by cellular detachment; it remains baffling whether another form of cell death can occur upon dissociation in hESCs. Here, we demonstrate that iron accumulation and subsequently lipid peroxidation are responsible for dissociation-mediated hESC death. Moreover, we found that a decrease of glutathione peroxidase 4 because of iron accumulation promotes ferroptosis. Inhibition of lipid peroxidation (ferrostatin-1) or chelating iron (deferoxamine) largely suppresses iron accumulation-induced ferroptosis in dissociated hESCs. The results show that P53 mediates the dissociation-induced ferroptosis in hESCs, which is suppressed by pifithrin α. Multiple genes involved in ferroptosis are regulated by the nuclear factor erythroid 2-related factor 2 (Nrf2). In this study, solute carrier family 7 member 11 and glutathione peroxidase 4 are involved in GSH synthesis decreased upon dissociation as a target of Nrf2. In conclusion, our study demonstrates that iron accumulation as a consequence of cytoskeleton disruption appears as a pivotal factor in the initiation of ferroptosis in dissociated hESCs. Nrf2 inhibits ferroptosis via its downstream targets. Our study suggests that the antiferroptotic target might be a good candidate for the maintenance of hESCs.