Shifting osteogenesis in vascular calcification.

Transitions between cell fates commonly occur in development and disease. However, reversing an unwanted cell transition in order to treat disease remains an unexplored area. Here, we report a successful process of guiding ill-fated transitions toward normalization in vascular calcification. Vascular calcification is a severe complication that increases the all-cause mortality of cardiovascular disease but lacks medical therapy. The vascular endothelium is a contributor of osteoprogenitor cells to vascular calcification through endothelial-mesenchymal transitions, in which endothelial cells (ECs) gain plasticity and the ability to differentiate into osteoblast-like cells. We created a high-throughput screening and identified SB216763, an inhibitor of glycogen synthase kinase 3 (GSK3), as an inducer of osteoblastic-endothelial transition. We demonstrated that SB216763 limited osteogenic differentiation in ECs at an early stage of vascular calcification. Lineage tracing showed that SB216763 redirected osteoblast-like cells to the endothelial lineage and reduced late-stage calcification. We also found that deletion of GSK3β in osteoblasts recapitulated osteoblastic-endothelial transition and reduced vascular calcification. Overall, inhibition of GSK3β promoted the transition of cells with osteoblastic characteristics to endothelial differentiation, thereby ameliorating vascular calcification