Comprehensive analysis of molecular pathways and key genes involved in lumbar disc herniation

Based on the Thompson classification of intervertebral discs (IVDs), we systematically analyzed gene expression differences between severely degenerated and mildly degenerated IVDs and explored the underlying molecular mechanisms using bioinformatics methods and multichip integration. We used multiomics analysis, includes mRNA microarray and methylation chips, to explore the genetic network and mechanisms of lumbar disc herniation (LDH). Subsequently, the Combat function of the R language SVA package was applied to eliminate heterogeneity between the gene expression data. And the protein–protein interaction (PPI) network, gene ontology (GO), and molecular pathways were used to constructs the mechanisms network. Consequently, we obtained 149 differentially expressed genes. Related molecular pathways are the following: ribosome activity, oxidative phosphorylation, extracellular matrix response. Besides, through PPI network analysis, genes with higher connectivity such as UBA52, RPLP0, RPL3, RPLP2, and RPL27 were also identified, suggesting that they play important regulatory roles in the complex network associated with LDH. Additionally, cg12556991 (RPL27) and cg06852319 (RPLP0) were found to be LDH-related candidate DNA methylation modification sites in the IVDs tissue of LDH patients. In conclusions, ribosome activity, oxidative phosphorylation, and extracellular matrix response may be potential molecular mechanisms underlying LDH, while hub genes involved in UBA52, RPLP0, RPL3, RPLP2, and RPL27, and candidate DNA methylation modification sites of cg12556991and cg06852319 are likely key regulators in the development of LDH.