Screening of differentially expressed microRNAs in degenerative intervertebral disc and investigation about the involvement of JNK pathway in IVDD / 中华骨科杂志

ABSTRACT

Objective To screen and validate differentially expressed microRNAs in human degenerative nucleus pulposus cells (NPCs) and to predict their target genes,and to investigate the role of JNK pathway in degenerative intervertebral disc disease.Methods Eight degenerative nucleus pulposus tissues were harvested from 8 patients (6 males and 2 females) with lumbar degenerative disease,and three normal nucleus pulposus tissues were harvested from 3 patients (3 males) with lumbar fracture,intraoperatively.Differentially expressed microRNAs were screened by microRNA microarray analysis and validated by real-time qPCR.Target genes of highly expressed microRNAs were predicted by analyzing information from data basesMicroCosm v5,TargetScan 5.1 and microRNA.org.Signal pathways associated with the target genes were analyzed,and qPCR was used to validate the screening results.Results Twenty differentially expressed microRNAs were identified.The microRNA-513a-5p and microRNA-494 were highly expressed in degenerative nucleus pulposus tissue,which was corresponding to the verification results,and the ratio was 2.222 2 and 2.948 5,respectively.Target genes of microRNA-513a-5p and microRNA-494 were MKK4 and JunD,respectively.MKK4 and JunD were both involved in JNK signaling pathway and located in upstream and downstream of this pathway,respectively.Conclusion In human degenerative nucleus pulposus cells,microRNA-513a-5p and microRNA-494 are highly expressed microRNAs,whose target genes are MKK4 and JunD,respectively.Both MKK4 and JunD are involved in JNK signaling pathway.These results indicate that JNK pathway may play important role in the pathogenesis of degenerative intervertebral disc disease.