CHIR99021 Maintenance of the Cell Stemness by Regulating Cellular Iron Metabolism

CHIR99021 is an aminopyrimidine derivative, which can efficiently inhibit the activity of glycogen synthesis kinase 3 alpha (GSK-3 alpha) and GSK-3 beta. As an essential component of stem cell culture medium, it plays an important role in maintaining cell stemness. However, the mechanism of its role is not fully understood. In the present study, we first found that removal of CHIR99021 from embryonic stem cell culture medium reduced iron storage in mouse embryonic stem cells (mESCs). CHIR99021-treated Neuro-2a cells led to an upregulation of ferritin expression and an increase in intracellular iron levels, along with GSK3 beta inhibition and Wnt/GSK-3 beta/beta-catenin pathway activation. In addition, iron treatment activated the classical Wnt pathway by affecting the expression of beta-catenin in the Neuro-2a cells. Our data link the role of iron in the maintenance of cell stemness via the Wnt/GSK-3 beta/beta-catenin signaling pathway, and identify intermediate molecules, including Steap1, Bola2, and Kdm6bos, which may mediate the upregulation of ferritin expression by CHIR99021. These findings reveal novel mechanisms of the maintenance of cell stemness and differentiation and provide a theoretical basis for the development of new strategies in stem cell treatment in disease.

Automated summary

CHIR99021 is a compound that inhibits the activity of GSK-3 alpha and GSK-3 beta. It is important in maintaining stem cell stemness, but its mechanism is not fully understood. This study found that removal of CHIR99021 from the culture medium reduced iron storage in embryonic stem cells.