初级纤毛及PGE-2信号通路在振动促进成骨细胞成骨中的机制研究

Osteoporosis is one of the main diseases that endanger the life and health of the elderly. In recent years, low magnitude high frequency vibration (LMHFV) characterized by a non-invasive method, low cost,less side effects, good compliance and other characteristics, have become an effective way in the prevention and treatment of osteoporosis. However, the mechanism of LMHFV increases bone formation and inhibits bone resorption remains unclear. We have preliminary data in the lab demonstrating: the expression of OCN, ALP and COL-1was up-regulated by LMHFV loading, and the promoting effect was blocked by the use of the hydrate to remove the primary cilia. Other works demonstrated: the PGE-2 signaling pathway was closely related to the formation and function of primary cilia, and they could promote the osteogenesis of osteoblasts under mechanical stimulation. This suggests that osteoblasts can feel the low mechanical vibration through the primary cilia, and then regulate the ability of osteogenesis via the PGE-2 dependent signaling pathway. The research on this subject has not been reported at home and abroad. This research will take this as the breakthrough point, to study how LMHFV activates PGE-2 dependent signaling pathways through the primary cilia, and affects the function of osteoblasts. This will deepen the application of LMHFV therapy in the orthopedical diseases(such as osteoporosis, nonunion), and provide theoretical basis and guidance for the development of new drugs to promote fracture healing or to prevent and cure heterotopic ossification.

骨质疏松症是危及老年人生命与健康的主要疾病之一。高频率低载荷机械振动（LMHFV）作为一种非药物疗法，针对骨质疏松症取得了较好的疗效，同时具有副作用小、费用低及患者依从性好等优点。我们的预实验显示：LMHFV加载能够上调成骨细胞成骨相关蛋白OCN、ALP、COL-1的表达，而使用水合氯醛去除初级纤毛后，该促进作用被阻断。另有研究发现：PGE-2信号通路与初级纤毛的形成和功能密切相关，初级纤毛与PGE-2信号通路能在机械刺激下促进成骨细胞成骨。这提示:成骨细胞能够通过初级纤毛感受低载荷机械振动，再通过PGE-2相关信号通路调节成骨细胞的成骨。关于这方面的研究，国内外未见报道。本课题将以此为切入点，研究LMHFV是如何通过初级纤毛，影响PGE-2相关信号通路，激活成骨细胞功能的。这将阐释振动等机械应力对成骨影响的机制，为深化LMHFV在骨科疾病的应用提供理论依据。

高频率低载荷机械振动（LMHFV）作为一种非药物疗法，针对骨质疏松症取得了较好的疗效，同时具有副作用小、费用低及患者依从性好等优点。但LMHFV对骨平衡产生积极影响的机制仍不清楚。本课题通过研究LMHFV是如何通过初级纤毛与PGE-2相关信号通路相互作用，激活成骨细胞功能，对LMHFV的成骨机制进行了初步研究。本课题首先验证LMHFV可以促进成骨细胞成骨，振动能够改变初级纤毛的形态结构。然后建立IFT88基因沉默细胞株，抑制初级纤毛的形成，研究其对成骨细胞在LMHFV下增殖、分化能力的影响，以及对PGE-2及PGE-2受体表达的影响；抑制细胞PGE-2的表达，研究在LMHFV影响下成骨细胞增殖、分化能力的改变，及初级纤毛的改变；最后应用PGE-2受体抑制剂，研究在LMHFV影响下成骨细胞生物学特性的改变，胞内PGE-2细胞通路关键因子的改变。研究显示：成骨细胞感受振动刺激后，细胞的初级纤毛变短，数量变少，并促进成骨细胞成骨。变化的初级纤毛，能够自我修复。在振动刺激下，成骨细胞的初级纤毛能激活胞内PGE-2信号通路，引起成骨细胞向外释放PGE-2，上调胞外PGE-2浓度。同时初级纤毛感受振动刺激后，引起PGE-2受体EP4增加，在上调的PGE-2作用下激活相关的信号通路，影响成骨细胞成骨。最后PGE-2信号通路能够促进成骨细胞初级纤毛在应力作用后的自我修复。此研究为阐释振动等机械应力对成骨影响的机制，深化LMHFV在骨科疾病的应用提供理论依据。项目资助发表核心论文1篇，待发表两篇。培养硕士生3名。项目投入经费22万元，支出19.6858万元，各项支出基本与预算相符。剩余经费2.3142万元，剩余经费计划用于本项目研究后续支出。