Institute of Oral Research, School of Stomatology, Kunming Medical University, Kunming, Yunnan, 650500, China.
Department of Orthodontics, Affiliated Stomatology Hospital of Kunming Medical University, Kunming, Yunnan, 650000, China.
Biochem Biophys Res Commun. 2020 Jun 18;527(1):83-89. doi: 10.1016/j.bbrc.2020.04.090. Epub 2020 Apr 27.
Static magnetic fields (SMF) have been proved to enhance osteogenic differentiation in mesenchymal stem cells (MSCs). However, the effect of SMF on mandibular condylar chondrocytes (MCCs) are less investigated, which contributes to the vertical formation of mandible. The purpose of the present study was to identify whether SMF accelerate the osteogenesis on mature condylar cartilage and explore the potential regulatory mechanism.
In this study, we presented a 280 mT SMF stimulation set-up to investigate the genomic effects of SMF exposure on MCCs differentiation and osteoblast-related factor secretion in vitro. Induced by Oricell™ for osteogenesis, MCCs from primary SD Rat were stimulated with or without SMF for cell culture. Cell proliferation was determined by CCK-8. The enhanced osteogenetic capacity of the SMF stimulated MCCs was identified by Alizarin red staining (ARS). Additionally, the effects of SMF on the expression of transmembrane protein marker (FLRT3), terminal differentiation markers (BMP2), and transcription factors (Smad1/5/8) were quantified by Western blot and immunofluorescence analysis.
Compared with the control group, SMF decreased the proliferation of MCCs (p < 0.05) after 14 days osteogenesis-specific induction. The mineral synthesis of MCCs was upregulated by SMF (p < 0.0001). The expression of BMP2, Smad1/5/8 showed decrease trends while the protein level of FLRT3 acted in contrary manner (p < 0.05).
Our findings emphasized the ability of osteogenesis positively respond to SMF stimulation by exhibiting enhanced differentiation via FLRT/BMP signaling.
静磁场（SMF）已被证明可增强间充质干细胞（MSCs）的成骨分化。然而，SMF 对下颌髁突软骨细胞（MCCs）的影响研究较少，而后者有助于下颌的垂直发育。本研究旨在确定 SMF 是否能加速成熟髁突软骨的成骨作用，并探讨其潜在的调节机制。
在这项研究中，我们提出了一种 280 mT 的 SMF 刺激装置，以研究 SMF 暴露对 MCCs 分化和成骨相关因子分泌的基因组影响。通过 Oricell™ 诱导成骨，将来自原代 SD 大鼠的 MCCs 在有或没有 SMF 的情况下进行细胞培养刺激。通过 CCK-8 测定细胞增殖。通过茜素红染色（ARS）鉴定 SMF 刺激的 MCCs 增强的成骨能力。此外，通过 Western blot 和免疫荧光分析定量测定 SMF 对跨膜蛋白标志物（FLRT3）、终末分化标志物（BMP2）和转录因子（Smad1/5/8）表达的影响。
与对照组相比，SMF 减少了 14 天成骨特异性诱导后 MCCs 的增殖（p < 0.05）。SMF 上调了 MCCs 的矿化合成（p < 0.0001）。BMP2、Smad1/5/8 的表达呈下降趋势，而 FLRT3 的蛋白水平则相反（p < 0.05）。
我们的研究结果强调了 MCCs 通过 FLRT/BMP 信号正向响应 SMF 刺激的能力，表现为通过增强分化来促进成骨作用。
