Identification Of Bone Morphometric Protein-related Hub Genes And Construction Of A Transcriptional Regulatory Network In Patients With Ossification Of The Ligamentum Flavum

Objective: Ossification of the ligamentum flavum(OLF)is initiated by elastic fiber reduction and collagen fiber proliferation,followed by chondral differentiation of mesenchymal stem cells in the ligamentum flavum and endochondral ossification.However,the exact etiology and pathological mechanism of OLF remain unclear.Bone morphogenetic proteins(BMPs)are pleiotropic osteoinductive proteins of the transforming growth factor-beta family and have been implicated in the formation of new bone and cartilage.This study aimed to identify BMP-related hub genes in OLF and analyze their functional characteristics.Methods: Differentially expressed genes(DEGs)were identified between OLF and normal LF groups and then intersected with BMP-related genes to obtain differentially expressed BMP-related genes(DEBRGs).The least absolute shrinkage selection operator(LASSO)and support vector machine recursive feature elimination(SVM-RFE)were used to screen hub genes.Furthermore,a receiver operating characteristic curve was plotted to verify the diagnostic values of the hub genes,and a competing endogenous(ce)RNA regulatory network was constructed to explain the expression regulation of the hub gene in OLF.Finally,the protein and m RNA expression levels of the hub genes were verified using western blot and real-time polymerase chain reaction(RT-PCR),respectively.Results: We identified 671 DEGs that were closely associated with OLF and 32 DEBRGs after intersecting the DEGs and BMP-related genes.Hub genes ADIPOQ,SCD,SCX,RPS18,WDR82,and SPON1,which were identified via LASSO and SVM-RFE analyses,showed high diagnostic values for OLF.Furthermore,the ce RNA network revealed the regulatory mechanisms of the hub genes.RT-PCR showed that the m RNA expression of the hub genes was significantly downregulated in the OLF group compared with the non-ossified LF(non-OLF)group.Western blot showed that the protein levels of ADIPOQ,SCD,WDR82,and SPON1 were significantly downregulated,whereas those of SCX and RPS18 were significantly up-regulated in the OLF group compared with the nonOLF group.Conclusion: ADIPOQ,SCD,SCX,RPS18,WDR82,and SPON1 were identified as hub genes for OLF.This study is the first to identify BMP-related genes in OLF pathogenesis through bioinformatics analysis.The identified genes may serve as potential therapeutic targets for treating patients with OLF.