Effect of Melatonin on the Extracellular-Regulated Kinase Signal Pathway Activation and Human Osteoblastic Cell Line hFOB 1.19 Proliferation.

Xiao-Chuan Xiong,Yue Zhu,Rui Ge,Wei Yuan,Li-Feng Liu

doi:10.3390/ijms160510337

Abstract

It has been shown that melatonin may affect bone metabolism. However, it is controversial whether melatonin could promote osteoblast proliferation, and the precise molecular mechanism of melatonin on osteoblast proliferation is still obscure. In this study, the results of the CCK-8 assay showed that melatonin significantly promoted human osteoblastic cell line hFOB 1.19 cell proliferation at 1, 2.5, 5, 10, 25, 50 and 100 µM concentrations for 24 h, but there were no significant differences among the groups. Western blot demonstrated that 10 µM melatonin significantly promoted ERK1/2 phosphorylation. Furthermore, we also detected the phosphorylation of c-Raf, MEK1/2, p90RSK and MSK1, and all of them increased with 10 µM melatonin. U0126 (a selective inhibitor of MEK that disrupts downstream activation of ERK1/2) downregulated the phosphorylation of ERK1/2, p90RSK and MSK1. U0126 also attenuated the proliferation of osteoblasts stimulated by melatonin. In conclusion, this study for the first time indicates that melatonin (10 nM–100 µM) promotes the proliferation of a human osteoblastic cell line hFOB 1.19 through activation of c-Raf, MEK1/2, ERK1/2, p90RSK and MSK1.

Highlights

Melatonin is involved in many physiological processes [1,2,3,4], including sleep, anti-inflammatory functions, gastrointestinal physiology, regulation of body core temperature, blood pressure, cardiovascular function, immune regulatory properties, antioxidative defense, detoxification, reproduction, inhibition of apoptosis and bone physiology [3,4,5,6,7,8,9,10]
To determine the effect of melatonin on the proliferation of hFOB 1.19 and to ascertain the specific concentration for the step of research, the Cell Counting Kit-8 (CCK-8) assay was performed on the hFOB cells
Melatonin slightly promoted hFOB cell proliferation at indicated concentrations for 4 h, but there was no statistical significance compared with the control group

Summary

Introduction

Melatonin is involved in many physiological processes [1,2,3,4], including sleep, anti-inflammatory functions, gastrointestinal physiology, regulation of body core temperature, blood pressure, cardiovascular function, immune regulatory properties, antioxidative defense, detoxification, reproduction, inhibition of apoptosis and bone physiology [3,4,5,6,7,8,9,10]. Some other organs can synthesize melatonin, such as gastrointestinal tract, retina and bone marrow [1]. Mouse and human bone marrow cells are capable of de novo synthesis of melatonin, which may have intracellular and or paracrine functions [11,12]. Some studies indicated that melatonin tended to promote osteoblasts differentiation and bone formation [14,15,16]. K.H. et al [20] indicated that melatonin promoted mouse osteoblastic

Methods

Results

Conclusion