Melatonin reverses tumor necrosis factor-alpha-induced metabolic disturbance of human nucleus pulposus cells via MTNR1B/Gαi2/YAP signaling
Xianjian Qiu, Tongzhou Liang, Zizhao Wu, Yuanxin Zhu, Wenjie Gao, Bo Gao, Jincheng Qiu, Xudong Wang, Taiqiu Chen, Zhihuai Deng, Pengfei Li, Yanbo Chen, Hang Zhou, Yan Peng, Caixia Xu, Peiqiang Su, Anjing Liang, Dongsheng Huang
Abstract
Background: Intervertebral disc degeneration (IDD), the main cause of low back pain, is closely related to the inflammatory microenvironment in the nucleus pulposus (NP). Tumor necrosis factor- (TNF-) plays an important role in inflammation-related metabolic disturbance of NP cells. Melatonin has been proven to regulate the metabolism of NP cells, but whether it can protect NP cells from TNF--induced damage is still unclear. Therefore, this study aims to investigate the role and specific mechanism of melatonin on regulating the metabolism of NP cells in the inflammatory microenvironment. Methods: Western blotting, RT-qPCR and immunohistochemistry were used to detect the expression of melatonin membrane receptors (MTNR1A/B) and TNF- in human NP tissues. In vitro, human primary NP cells were treated with or without vehicle, TNF- and melatonin. And the metabolic markers were also detected by western blotting and RT-qPCR. The activity of NF-B signaling and Hippo/YAP signaling were assessed by western blotting and immunofluorescence. Membrane receptors inhibitors, pathway inhibitors, lentiviral infection, plasmids transfection and immunoprecipitation were used to explore the specific mechanism of melatonin. In vivo, the rat IDD model was constructed and melatonin was injected intraperitoneally to evaluate its therapeutical effect on IDD.