This study investigated the mechanism of microRNA-21 in regulating IL-6 inflammatory response and cell autophagy in intervertebral disc degeneration. A total of 10 patients with lumbar disc herniation accompanied by nerve root pain (observation group) and 10 patients with lumbar burst fractures (control group) were selected. The nucleus pulposus tissues of the lesion were obtained during operation for cell culture. Real-time quantitative polymerase chain reaction (PCR) was used to detect the expression of microRNA-21. The ELISA method was used to detect the levels of IL-6, and type II collagen (Col II). Aggrecan and western blotting was used to detect autophagy-related gene 7 (ATG7) and microtubule-associated protein 1 light chain 3 (LC3)-II/-I. As a result, the levels of microRNA-21 and IL-6 in the observation group were significantly higher than those in the control group, but the levels of Col II and aggrecan were significantly lower than those in the control group. The differences were statistically significant (P<0.05). The levels of ATG7 and LC3-II/-I in the observation group were significantly decreased (P<0.05). In conclusion, the expression of microRNA-21 is abnormally high in the nerve root pain of the lumbar intervertebral disc, which can increase the IL-6 inflammatory response and reduce the capacity of cell autophagy.
Keywords: IL-6; cell autophagy; inflammatory response; intervertebral disc degeneration; lumbar intervertebral disc; microRNA-21.