Sorafenib inhibits ossification of the posterior longitudinal ligament by blocking LOXL2-mediated vascularizationOAMEDLINE

Ossification of the Posterior Longitudinal Ligament(OPLL)is a degenerative hyperostosis disease characterized by the transformation of the soft and elastic vertebral ligament into bone,resulting in limited spinal mobility and nerve compression.Employing both bulk and single-cell RNA sequencing,we elucidate the molecular characteristics,cellular components,and their evolution during the OPLL process at a single-cell resolution,and validate these findings in clinical samples.This study also uncovers the capability of ligament stem cells to exhibit endothelial cell-like phenotypes in vitro and in vivo.Notably,our study identifies LOXL2 as a key regulator in this process.Through gain-and loss-of-function studies,we elucidate the role of LOXL2 in the endothelial-like differentiation of ligament cells.It acts via the HIF1A pathway,promoting the secretion of downstream VEGFA and PDGF-BB.This function is not related to the enzymatic activity of LOXL2.Furthermore,we identify sorafenib,a broad-spectrum tyrosine kinase inhibitor,as an effective suppressor of LOXL2-mediated vascular morphogenesis.By disrupting the coupling between vascularization and osteogenesis,sorafenib demonstrates significant inhibition of OPLL progression in both BMP-induced and enpp1 deficiency-induced animal models while having no discernible effect on normal bone mass.These findings underscore the potential of sorafenib as a therapeutic intervention for OPLL.