IncRNA/circRNA-miRNA-mRNA ceRNA network in lumbar intervertebral disc degeneration

Abstract

Accumulating evidence has indicated that noncoding RNAs are involved in intervertebral disc degeneration (IDD); however, the competing endogenous RNA (ceRNA)-mediated regulatory mechanisms in IDD remain rarely reported. The present study aimed to comprehensively investigate the alterations in expression levels of circular RNA (circRNA), long noncoding RNA (IncRNA), microRNA (miRNA/miR) and mRNA in the nucleus pulposus (NP) of patients with IDD. In addition, crucial IncRNA/circRNA-miRNA-mRNA ceRNA interaction axes were screened using the GSE67567 microarray dataset obtained from the Gene Expression Omnibus database. After data preprocessing, differentially expressed circRNAs (DECs), IncRNAs (DELs), miRNAs (DEMs) or genes (DEGs) between IDD and normal controls were identified using the Linear Models for Microarray data method. A protein-protein interaction (PPI) network was constructed for DEGs based on protein databases, followed by module analysis. The ceRNA network was constructed based on the interaction between miRNAs and mRNAs, and IncRNAs/circRNAs and miRNAs. The underlying functions of mRNAs were predicted using the Database for Annotation, Visualization and Integrated Discovery database. The present study identified 636 DECs, 115 DELs, 84 DEMs and 1,040 DEGs between patients with IDD and control individuals. PPI network analysis demonstrated that Fos proto-oncogene, AP-1 transcription factor subunit (FOS), mitogen-activated protein kinase 1 (MAPK1), hypoxia inducible factor 1 subunit a (HIF1A) and transforming growth factor pi (TGFB1) were hub genes and enriched in modules. Metastasis-associated lung adenocarcinoma transcript 1 (MALATl)/hsa_drcRNA_102348-hsa-miR-185-5p-TGFBl/FOS, MALATl-hsa-miR-155-5p-HIFlA, hsa_circRNA_102399-hs a-miR-302a-3p-HIFlA, MALATl-hsa-miR-519d-3p-MAPKl and hsa_circRNA_100086-hsa-miR-509-3p-MAPKl ceRNA axes were obtained by constructing the ceRNA networks. In conclusion, these identified ceRNA interaction axes may be crucial targets for the treatment of IDD.