Osthol effects on the proliferation and differentiation of osteoblasts based on endoplasmic reticulum stress / 中国组织工程研究

ABSTRACT

BACKGROUND: Osthol has been reported to promote osteogenesis by increasing osteoblast proliferation, but the anti-osteoporosis mechanism underlying osthol is poorly understood.OBJECTIVE:To observe the effect of osthol on the proliferation and differentiation of rat osteoblasts in vitro and to explore its mechanism of anti-osteoporosis effect. METHODS: Rat osteoblasts were isolated by secondary enzyme digestion and identified by alkaline phosphatase staining and mineralized nodule staining. There were five groups blank control, solvent control, β-estradiol as well as low-, medium- and high-dose osthol groups. Cell proliferation was detected by cell counting kit-8 assay, and cell differentiation was evaluated by detection of alkaline phosphatase and mineralized nodule staining. The expression levels of GRP78, PDI and CHOP were detected by western blot assay. RESULTS AND CONCLUSION: Osthol at the concentrations of 1x10-4and 1x10-5mol/L could inhibit osteoblast proliferation. 1x10-4mol/L osthol could increase the activity of alkaline phosphatase in osteoblasts and enhance osteoblastic mineralization. Meanwhile, 1x10-4mol/L osthol was able to down-regulate the expression level of GRP78 and up-regulate the expression levels of PDI and CHOP. To conclude, osthol can promote osteoblast differentiation and inhibit osteoblast proliferation probably by endoplasmic reticulum stress.