Fig. 1

NP tissues from IDD patients showed decreased miR-217 expression. A Graph depicting the scatter plot of miRNA expression profiles between IDD patients and the control group (The axes represent expression fold in the IDD or control group. Genes were considered to be differentially expressed if they had an absolute log2-fold change of >2. Red dots indicate no difference between IDD and controls; green dots indicate more than a twofold increase; blue dots indicate more than a twofold decrease). B Heatmaps of 21 miRNAs that were found to be differentially expressed. C The volcano graph depicts the difference in miRNA expression levels between patients with IDD and healthy individuals in the control group. The purple dots on the right represent miRNAs that were upregulated, and the red dots on the left represent miRNAs that were downregulated. miR-217 is indicated. D The expression of miR-217 in human nucleus pulposus tissues was determined using qRT–PCR. E The expression of miR-217 in human nucleus pulposus cells was determined using qRT–PCR. F FISH analysis was performed on individuals with IDD as well as on the control group. Scale bar = 50 μm. G IDD Pfirrmann scores were shown to be negatively associated with miR-217 expression levels (r = −0.896, ***P < 0.001). H Methylation of the miR-217 promoter region. I Comparison of the methylation status of IDD patients (n=18) and controls (n=11). IDD, intervertebral disc degeneration; miR, microRNA; FC, fold change; DAPI, 4′,6-diamidino-2-phenylindole. ***P < 0.001