Targeting of CDKN1B by miR‐222‐3p may contribute to the development of intervertebral disc degeneration

MicroRNAs (miRNAs) are small endogenous non‐coding RNAs that can negatively regulate the expression of their complementary mRNA targets, and have been implicated in various pathophysiological processes. In this study, we examined the effect of miR‐222‐3p on intervertebral disc degeneration (IDD). We found that expression of miR‐222‐3p was significantly higher in IDD tissues than in normal intervertebral disc tissue, and report that overexpression of miR‐222‐3p remarkably increased apoptosis and reduced proliferation of nucleus pulposus (NP) cells. In addition, miR‐222‐3p promoted secretion of matrix metalloproteinase‐3, and decreased collagen type II and aggrecan production. Cyclin‐dependent kinase inhibitor 1B (CDKN1B) was identified as a direct target of negative regulation by miR‐222‐3p in NP cells, and expression of miR‐222‐3p was found to be negatively correlated with that of CDKN1B in IDD tissue. Finally, we observed that transfection with miR‐222‐3p dramatically reduced CDKN1B expression in NP cells. In conclusion, miR‐222‐3p may be involved in IDD development, possibly through targeting CDKN1B.