ABSTRACT
BACKGROUND:Fracture healing is the coupling interaction of osteoblasts and osteoclasts that promotes bone growth, in which osteoblast-mediated bone resorption and osteoclasts-mediated bone reconstruction make the bone reconstruction in a dynamic equilibrium to promote bone growth. However, the majorities of the current studies focus on osteogenic or osteoclastic mechanism alone, and ignore the interaction mechanism between these two cels under co-existing conditions. OBJECTIVE:To investigate the effects of Kidney Chinese Herbs on osteoblasts and osteoclasts coupling of osteoprotegerin-receptor activator of nuclear factor kappaB ligand-receptor activator of nuclear factor kappaB and its mechanism of action in fracture treatment. METHODS: Mouse osteoblasts and osteoclasts were isolated and cultured in vitro to establish the mouse “osteoblast-osteoclast co-culture system” as a research platform. Then, Kidney Chinese Herbs at doses of 1.25, 2.5, 6.25 g/(kg?d) were given intragastricaly for 7 consecutive days. Mice in the blank control group were fed with the same volume of normal saline. RESULTS AND CONCLUSION:The alkaline phosphatase activity in osteoblasts co-cultured with osteoclasts was significantly higher than that in osteoblasts cultured alone at 24 hours of culture (P < 0.05). Real-time PCR showed that in the co-culture system, the expression of alkaline phosphatase, Runt related transcription factor 2 and osteoprotegerin were increased in a dose-dependent manner (P < 0.05). Western blot assay showed 6.25 g/(kg?d) Kidney Chinese Herbs could dramaticaly promote the expression of osteoprotegerin and receptor activator of nuclear factor kappaB ligand, but restrained the expression of receptor activator of nuclear factor kappaB (P < 0.05). These findings indicate that Kidney Chinese Herbs can dynamicaly regulate the osteoprotegerin-receptor activator of nuclear factor kappaB ligand-receptor activator signaling pathway, and has a positive effect to promote bone reconstruction and rehabilitation.