Wang William Wei-Jun, Man Gene Chi-Wai, Wong Jack Ho, Ng Tzi-Bun, Lee Kwong-Man, Ng Bobby Kin-Wah, Yeung Hiu-Yan, Qiu Yong, Cheng Jack Chun-Yiu
Department of Spine Surgery, Drum Tower Hospital, Nanjing University Medical School, Nanjing 210008, China.
Department of Obstetrics and Gynaecology, Faculty of Medicine, the Chinese University of Hong Kong, Hong Kong, China.
Int J Mol Sci. 2014 Sep 25;15(9):17100-14. doi: 10.3390/ijms150917100.
Abnormalities in the melatonin signaling pathway and the involvement of melatonin receptor MT2 have been reported in patients with adolescent idiopathic scoliosis (AIS). Whether these abnormalities were involved in the systemic abnormal skeletal growth in AIS during the peripubertal period remain unknown. In this cross-sectional case-control study, growth plate chondrocytes (GPCs) were cultured from twenty AIS and ten normal control subjects. Although the MT2 receptor was identified in GPCs from both AIS and controls, its mRNA expression was significantly lower in AIS patients than the controls. GPCs were cultured in the presence of either the vehicle or various concentrations of melatonin, with or without the selective MT2 melatonin receptor antagonist 4-P-PDOT (10 µM). Then the cell viability and the mRNA expression of collagen type X (COLX) and alkaline phosphatase (ALP) were assessed by MTT and qPCR, respectively. In the control GPCs, melatonin at the concentrations of 1, 100 nM and 10 µM significantly reduced the population of viable cells, and the mRNA level of COLX and ALP compared to the vehicle. Similar changes were not observed in the presence of 4-P-PDOT. Further, neither proliferation nor differentiation of GPCs from AIS patients was affected by the melatonin treatment. These findings support the presence of a functional abnormality of the melatonin signaling pathway in AIS GPCs, which might be associated with the abnormal endochondral ossification in AIS patients.
青少年特发性脊柱侧凸（AIS）患者中已报道褪黑素信号通路异常以及褪黑素受体MT2的参与情况。这些异常是否参与了青春期前后AIS患者的全身骨骼异常生长仍不清楚。在这项横断面病例对照研究中，从20名AIS患者和10名正常对照受试者中培养生长板软骨细胞（GPC）。虽然在AIS患者和对照的GPC中都鉴定出了MT2受体，但其mRNA表达在AIS患者中显著低于对照组。将GPC在载体或不同浓度褪黑素存在的情况下培养，有或没有选择性MT2褪黑素受体拮抗剂4-P-PDOT（10 μM）。然后分别通过MTT和qPCR评估细胞活力以及X型胶原（COLX）和碱性磷酸酶（ALP）的mRNA表达。在对照GPC中，与载体相比，浓度为1、100 nM和10 μM的褪黑素显著降低了活细胞数量以及COLX和ALP的mRNA水平。在存在4-P-PDOT的情况下未观察到类似变化。此外，褪黑素处理对AIS患者的GPC增殖和分化均无影响。这些发现支持AIS的GPC中存在褪黑素信号通路功能异常，这可能与AIS患者的软骨内成骨异常有关。
