Melatonin Alleviates Radiculopathy Against Apoptosis and NLRP3 Inflammasomes Via the Parkin-Mediated Mitophagy Pathway. Issue 16 (15th August 2021)

• Record Type: Journal Article
• Authors: Xie, Lin; Zhao, Zhiming; Chen, Zhenhao; Ma, Xiaosheng; Xia, Xinlei; Wang, Hongli; Zheng, Chaojun; Jiang, Jianyuan
• Is Part Of: Spine. Volume 46:Issue 16(2021)
• Publication Date: 2021-08-15
• Subjects: dorsal root ganglion -- melatonin -- mitophagy -- NLR pyrin domain containing 3 inflammasome -- radiculopathy; Spine -- Abnormalities -- Periodicals; Spine -- Diseases -- Periodicals; Spine -- Surgery -- Periodicals; 616.73005
• DOI: 10.1097/BRS.0000000000003942
• Languages: English
• ISSNs: 0362-2436

Abstract

Abstract : Study Design: Animal experimental study with intervention. Objective: To investigate the effect of melatonin on rat radiculopathy model and dorsal root ganglion (DRG) cells, and to elucidate the underlying mechanism. Summary of Background Data: Melatonin has a well-documented efficacy in intervertebral disc degeneration (IVDD) and low back pain. IVDD can also lead to other complications such as disc herniation which will cause radiculopathy. Herniated nucleus pulposus (NP) induced apoptosis and NLR pyrin domain containing 3 (NLRP3) activation in DRG. However, the effect and underlying mechanism of melatonin on radiculopathy and DRG cells are still unclear. Methods: Rat radiculopathy model was induced by implanting NP tissue from the tail disc of the same rat into the left L4/5 inter-laminar space near the left DRG. Melatonin was injected intraperitoneally in the treated group to test its function. Apoptosis was determined by Tunnel staining and flow cytometry. NLRP3 inflammasome activation was determined by levels of NLRP3, ASC, GSMDM-N, IL-1β, and Caspase-1. Mitophagy was determined by levels of Parkin, Beclin-1, p62, and LCB-II. Mitophagy was blocked by treatment with Parkin-si or cyclosporine A (CsA). Results: NLRP3 was significantly upregulated in DRG of rat radiculopathy model; moreover, melatonin markedly decreased pain behavior in rat radiculopathy model. Furthermore, melatonin treatment decreases the incidence of apoptosis in DRG cells. Melatonin also promotes mitophagy and inhibits NLRP3 inflammasomes in DRG cells. In addition, mitophagy was blocked by treatment with Parkin-si and CsA. Both Parkin-si and CsA attenuated melatonin's inhibitory effect on apoptosis and the NLRP3 inflammasome, indicating that the beneficial effects of melatonin in DRG cells are mediated through the Parkin-mediated mitophagy. Conclusion: Melatonin alleviates radiculopathy against apoptosis and NLRP3 inflammasomes by promoting Parkin-mediated mitophagy, which may help us provide a potential target for the treatment of radiculopathy. Level of Evidence: N/A Abstract : This study evaluated the protective role of melatonin on lumbar radiculopathy in a nucleus pulposus implantation model, TNF-α-induced dorsal root ganglion cells were used to explore potential mechanism.