Type I IFN signaling pathway promotes osteoblast differentiation through targeting Sox9 [scRNA-seq]
Ossification of the posterior longitudinal ligament (OPLL) is a progressive ectopic bone formation of ligaments and may lead to severe neurological symptoms. However, in addition to conservative therapy for neurological symptoms or surgical management, effective pharmacotherapy and preventive intervention for OPLL remains absent. Here, to reveal the potential therapeutic target we generate single-cell maps of T-OPLL patients. We found that type I IFN signaling pathway is significantly activated during the progression of ossification. Further, stimulation of IFN ß obviously promoted the calcium deposition of murine MC3T3-E1 preosteoblasts. We profiled the transcriptome in MC3T3-E1 cells after osteogenic induction, and found that IFN ß promoted the expression of Sox9 and SPP1. STAT1 positively regulated the expression of Sox9 and phosphorylated STAT1 occupied on the promoter of Sox9. We also observed the localization of Sox9 in the ossificated region of ligament from OPLL patients. Thus, Sox9 is a target gene of type I IFN pathway during osteogenic induction. Furthermore, blockage of IFNAR1 by anti-IFNAR1 neutralizing antibody significantly impeded osteoblast differentiation induced by IFN ß and display efficacy against ossification. Together, these results demonstrated that type I IFN signaling pathway promotes osteoblast differentiation. Anti-IFNAR1 neutralizing antibody could be used as a potential therapy for OPLL by blocking type I IFN signaling pathway. Overall design: To investigate the mechanisms of OPLL with single-cell RNA-seq.