Microarray based analysis of gene regulation by microRNA in intervertebral disc degeneration

The present study aimed to explore the underlying mechanism of the development of intervertebral disc degeneration (IDD) by bioinformatics based on microarray datasets. GSE 19943 and GSE 34095 datasets downloaded from Gene Expression Omnibus data were used to screen the differentially expressed genes (DEGs) in IDD. The correlation between microRNAs and target genes was investigated using different algorithms. The underlying molecular mechanisms of the target genes were then explored using Kyoto Encyclopedia of Genes and Genomes pathway and Gene Ontology function enrichment analysis. A total of 9 differentially expressed microRNAs, including 3 down- and 6 upregulated microRNAs and 850 DEGs were identified in tissue from patients with IDD. Two regulation networks of the target genes by microRNAs were constructed, including 33 upregulated microRNA-target gene pairs and 4 downregulated microRNA-target gene pairs. Certain target genes had been demonstrated to be involved in IDD progression via various pathways, including in the cell cycle and pathways in cancer. In addition, two important microRNAs (microRNA-222 and microRNA-589) were identified that were pivotal for the development of IDD, and their target genes, CDKNAB and SMAD4. In conclusion, a comprehensive miRNA-target gene regulatory network was constructed, which was found to be important in IDD progression.