Abstract: ［Abstract］ Objective To investigate the correlation of the serum expression of microRNA-494 and microRNA-125a with the degree of lumbar intervertebral disc degeneration.
Methods Forty-five patients with prolapse or protrusion of lumbar intervertebral disc were selected as degeneration group and 42 patients with low back pain as control group. All patients underwent lumbar MRI. The relationship between the degree of degeneration of lumbar intervertebral disc and Pfirrmann(PM) grade of intervertebral disc was analyzed via diffusion weighted magnetic resonance imaging(DWI).
Results In the control group, 126 intervertebral discs were examined, of which 99 were in grade Ⅰ and Ⅱ(normal), accounting for 78.6%(99/126), 27 were in grade Ⅲ, Ⅳ and Ⅴ, accounting for 21.4%(27/126).135 intervertebral discs were examined in the degeneration group, of which 66 were in grade Ⅰ and Ⅱ(normal), accounting for 12.6%(17/135),118 were in grade Ⅲ, Ⅳ and Ⅴ, accounting for 87.4%(118/135).There was significant difference in PM grading constituent ratio between two groups(P＜ 0.05), and the apparent diffusion coefficient(ADC) value in the degenerative group was lower than that in the control group(P＜0.05).The serum level of microRNA-125a in degenerative group was significantly lower whereas of serum microRNA-494 was significantly higher than that in control group(P＜0.05).The expression level of microRNA-125a in degenerative group was positively correlated with ADC value(r=0.853, P＜0.01), and the expression level of microRNA-494 was negatively correlated with ADC value(r=-0.897, P＜0.01).ROC curve analysis of microRNA-125a and microRNA-494 in serum showed that the area under the curve of microRNA-125a and microRNA-494 was 0.893(95%CI=0.815-0.971, P＜0.01) and 0.852(95%CI=0.762-0.932, P＜0.01), respectively. The sensitivity was 87.9% and 93.7%, specificity was 77.0% and 67.7%, accuracy was 80.0% and 77.7%, positive predictive value was 92.3% and 92.1%, negative predictive value was 81.8% and 76.9%, respectively.
Conclusion The expression of miRNA-494 and miRNA-125a in serum may be related to the pathogenesis of lumbar disc degeneration disease. Detecting their expression levels can provide a genetic basis for early diagnosis and treatment of lumbar disc degeneration disease.

Key words: lumbar intervertebral disc degeneration； magnetic resonance diffusion weighted imaging, microRNAs