Excessive systemic uptake of inorganic fluorides causes disturbances of bone homeostasis. The mechanism of skeletal fluorosis is still uncertain. This study aimed to study the effect of fluoride on osteocyte-driven osteoclastogenesis and probe into the role of PTH in this process. IDG-SW3 cells seeded in collagen–coated constructs were developed into osteocyte-like cells through induction of mineral agents. Then, osteocyte-like cells were exposed to fluoride in the presence or absence of parathyroid hormone (PTH). Cell viability and their capacity to produce receptor activator of nuclear factor kappa-B ligand (RANKL), osteoprotegerin (OPG) and sclerostin (SOST) were detected by MTT and Western blot assays, respectively. Finally, a transwell coculture system using osteocyte-like cells seeded in the low compartment, and osteoclast precursors added in the inserts was developed to observe the osteocyte-driven osteoclasogenesis response to fluoride with or without PTH, and the expression of molecules involved in this mechanism were measure by real time RT-PCR. Results showed that osteocytes withstood a toxic dose of fluoride, and yet PTH administration significantly reduced osteocytes viability. PTH amplified the effect of fluoride on the expression of osteoclastogenesis-related molecules in osteocyte, but did not enlarged the stimulating effect of fluoride on osteoclastogenesis drove by osteocyte coculture. Gene expression levels of TRAP, RANK, JNK and NFAtc1 significantly increased in fluoride affected osteoclast precursor cocultured with osteocyte-like cells. The impact of fluoride on osteocyte-driven osteoclast differentiation was stronger than that of PTH. In conclusion, osteocyte played a pivotal role on the mechanism underlying fluoride-affected osteoclastogenesis in which RANK-JNK-NFATc1 signaling pathway was involved, and PTH had a significant impact in this process.

全身摄入过量的无机氟化物会干扰骨稳态。骨骼氟中毒的机制仍不确定。这项研究旨在研究氟化物对骨细胞驱动的破骨细胞形成的影响，并探讨PTH在此过程中的作用。通过诱导矿物质，植入胶原蛋白涂层构建体中的IDG-SW3细胞被发育为类骨细胞。然后，在有或没有甲状旁腺激素（PTH）的情况下，使骨细胞样细胞暴露于氟化物。分别通过MTT法和Western blot法检测细胞活力及其产生核因子κB配体（RANKL），骨保护素（OPG）和硬化蛋白（SOST）受体激活剂的能力。最后，使用在低隔间播种的类骨细胞样细胞进行跨孔共培养系统，并开发了添加到插入物中的破骨细胞前体，以观察在有或没有PTH的情况下破骨细胞驱动的对氟的成骨作用，并通过实时RT-PCR测量参与该机制的分子的表达。结果表明，骨细胞能够耐受毒性剂量的氟化物，而PTH的施用却显着降低了骨细胞的生存能力。PTH增强了氟化物对骨细胞中破骨细胞形成相关分子表达的影响，但并未扩大氟化物对骨细胞共培养驱动的破骨细胞形成的刺激作用。在与骨细胞样细胞共培养的受氟影响的破骨细胞前体中，TRAP，RANK，JNK和NFAtc1的基因表达水平显着增加。氟化物对破骨细胞驱动的破骨细胞分化的影响强于PTH。