Fig. 1: Differential expression of circRNAs in degenerative and normal NP tissues and ceRNA analysis for circRNA_104670.

a The expression levels of circRNAs were recorded by a box plot as the mean ± standard deviation in the degenerative and normal NP groups. b Hierarchical clustering recorded the top 20 differentially expressed circRNAs between degenerative and normal NP tissues. The expression values are represented in different colors; red indicates high expression levels, and green indicates low expression levels. The red box indicates the selected circRNAs. c A scatter plot was used to evaluate the variation in circRNA expression. The values of the X and Y axes in the scatter plot correspond to the normalized signal values of the samples (log 2 scaled). The green lines are fold-change lines, the circRNAs above the top green and below the bottom line indicate greater than 1.5-fold changes between the two groups (p < 0.05). d Volcano plots were used to show differential expression of circRNAs. The vertical lines correspond to 1.5-fold up- and downregulation, with a p value of 0.05. The red point outside of the vertical lines in the plot shows the number of circRNAs that were differentially expressed with statistical significance between the two groups. e The interactions were specifically described basing on circRNA microarray and mRNA microarray data. In this network, 31 miRNAs were closely connected with circRNA_104670, while 26 miRNAs ranker higher. The hexagon at the center of the network indicates circRNA_104670, and the pink circles represent miRNAs that bound to this circRNA. The green quadrilaterals indicate target genes (miRNAs). The predicted interactions of ceRNA in the IDD process is circRNA_104670-miR-17-3p-MMP-2