Department of Preventive Dentistry, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, Beijing, China.
Department of Stomatology, Xuanwu Hospital Capital Medical University, Beijing, China.
Oral Dis. 2018 Oct;24(7):1270-1281. doi: 10.1111/odi.12900. Epub 2018 Jun 8.
To explore the role of dental follicle cells (DFCs) with a novel cleidocranial dysplasia (CCD) causative gene RUNX2 mutation (DFCs ) in delayed permanent tooth eruption.
A CCD patient with typical clinical features was involved in this study. DFCs were cultured and DNA was extracted for RUNX2 mutation screening. Measurements of cell proliferation, alkaline phosphatase (ALP) activity, alizarin red staining and osteoblast-specific genes expression were performed to assess osteogenesis of DFCs . Co-culture of DFCs and peripheral blood mononuclear cells (PBMCs), followed tartrate-resistant acid phosphatase (TRAP) staining, real-time PCR and western blot were performed to evaluate osteoclast-inductive capacity of DFCs .
A missense RUNX2 mutation (c. 557G>C) was found in DFCs from the CCD patient. Compared with normal controls, this mutation did not affect the proliferation of DFCs , but down-regulated the expression of osteogenesis-related genes, leading to a decrease in ALP activity and mineralisation. Co-culture results showed that DFCs reduced the formation of TRAP multinucleated cells and the expression of osteoclastogenesis-associated genes. Furthermore, the mutation reduced the ratio of RANKL/OPG in DFCs .
DFCs disturbs bone remodelling activity during tooth eruption through RANK/RANKL/OPG signalling pathway and may thus be responsible for impaired permanent tooth eruption in CCD patients.
探讨具有新型 cleidocranial dysplasia (CCD) 致病基因突变的牙囊细胞 (DFCs) 在恒牙迟萌中的作用。
本研究纳入了一位具有典型临床特征的 CCD 患者。培养 DFCs 并提取 DNA 进行 RUNX2 突变筛查。通过细胞增殖、碱性磷酸酶 (ALP) 活性、茜素红染色和成骨细胞特异性基因表达等检测方法评估 DFCs 的成骨能力。进行 DFCs 与外周血单核细胞 (PBMCs) 的共培养，然后进行抗酒石酸酸性磷酸酶 (TRAP) 染色、实时 PCR 和 Western blot，评估 DFCs 的破骨诱导能力。
在 CCD 患者的 DFCs 中发现了一个错义 RUNX2 突变 (c.557G>C)。与正常对照组相比，该突变并未影响 DFCs 的增殖，但下调了成骨相关基因的表达，导致 ALP 活性和矿化减少。共培养结果表明，DFCs 减少了 TRAP 多核细胞的形成和破骨细胞生成相关基因的表达。此外，该突变降低了 DFCs 中 RANKL/OPG 的比值。
DFCs 通过 RANK/RANKL/OPG 信号通路干扰牙齿萌出过程中的骨重塑活动，可能是 CCD 患者恒牙迟萌的原因。
