背景:牙周膜干细胞(PDLSCs)是组织工程和临床应用中重要的种子细胞。它们是用于感测各种机械应力的优先受体细胞。Yes相关蛋白(YAP)是公认的机械敏感转录因子。然而,YAP在张力应激(TS)下调节PDLSCs命运的作用及其机制尚不清楚。
方法:用荧光染色法研究TS对PDLSCs形态和命运的影响,透射电子显微镜,流式细胞术和定量实时聚合酶链反应(qRT-PCR)。然后qRT-PCR,西方印迹,免疫荧光染色和基因敲低实验研究YAP的表达和分布及其与PDLSCs增殖的相关性。随后通过添加细胞骨架抑制剂来探索细胞骨架动力学对YAP核易位的影响。通过qRT-PCR和western印迹证明细胞骨架动力学对LINC复合物表达的影响。腺病毒破坏LINC复合物后,研究了LINC复合物对YAP核易位和PDLSCs增殖的影响.然后进行线粒体相关检测以探索线粒体在YAP核易位中的作用。最后,通过构建Sprague-Dawley大鼠正畸牙齿移动模型对体外结果进行验证。
结果:TS增强了F-肌动蛋白的聚合和拉伸,上调LINC复合物的表达。这进一步加强了对核弹的拉力,扩大了核孔隙,并促进了YAP的核进入,从而增强增殖相关基因的表达。在这个过程中,线粒体沿着重建的微管运输到细胞核的外围。他们产生ATP以帮助YAP的核易位,并在一定程度上驱动F-肌动蛋白聚合。当LINC复合体被摧毁时,YAP的核易位被抑制,这限制了PDLSCs的增殖,牙周组织改建受阻,阻碍牙齿移动。
结论:我们的研究证实,适当的TS可以通过机械驱动的F-肌动蛋白/LINC复合物/YAP轴促进PDLSCs增殖和牙周组织重塑,为临床上种子细胞扩增和促进健康有效的牙齿移动提供理论指导。
BACKGROUND: Periodontal ligament stem cells (PDLSCs) are important seed cells in tissue engineering and clinical applications. They are the priority receptor cells for sensing various mechanical stresses. Yes-associated protein (YAP) is a recognized mechanically sensitive transcription factor. However, the role of YAP in regulating the fate of PDLSCs under tension stress (TS) and its underlying mechanism is still unclear.
METHODS: The effects of TS on the morphology and fate of PDLSCs were investigated using fluorescence staining, transmission electron microscopy, flow cytometry and quantitative real-time polymerase chain reaction (qRT-PCR). Then qRT-PCR, western blotting, immunofluorescence staining and gene knockdown experiments were performed to investigate the expression and distribution of YAP and its correlation with PDLSCs proliferation. The effects of cytoskeleton dynamics on YAP nuclear translocation were subsequently explored by adding cytoskeleton inhibitors. The effect of cytoskeleton dynamics on the expression of the LINC complex was proved through qRT-PCR and western blotting. After destroying the LINC complex by adenovirus, the effects of the LINC complex on YAP nuclear translocation and PDLSCs proliferation were investigated. Mitochondria-related detections were then performed to explore the role of mitochondria in YAP nuclear translocation. Finally, the in vitro results were verified by constructing orthodontic tooth movement models in Sprague-Dawley rats.
RESULTS: TS enhanced the polymerization and stretching of F-actin, which upregulated the expression of the LINC complex. This further strengthened the pull on the nuclear envelope, enlarged the nuclear pore, and facilitated YAP\'s nuclear entry, thus enhancing the expression of proliferation-related genes. In this process, mitochondria were transported to the periphery of the nucleus along the reconstructed microtubules. They generated ATP to aid YAP\'s nuclear translocation and drove F-actin polymerization to a certain degree. When the LINC complex was destroyed, the nuclear translocation of YAP was inhibited, which limited PDLSCs proliferation, impeded periodontal tissue remodeling, and hindered tooth movement.
CONCLUSIONS: Our study confirmed that appropriate TS could promote PDLSCs proliferation and periodontal tissue remodeling through the mechanically driven F-actin/LINC complex/YAP axis, which could provide theoretical guidance for seed cell expansion and for promoting healthy and effective tooth movement in clinical practice.