淫羊藿甙促进体外培养成骨细胞骨成形蛋白-2及OsterixmRNA表达

Icarrin increases bone morphogenetic protein 2 and Osterix expression in rat osteoblast

目的观察淫羊藿甙对体外培养成骨细胞增殖、分化以及骨成形蛋白-2（BMP-2）、成骨细胞特异性转录因子OsterixmRNA表达的影响，探讨淫羊藿抗骨质疏松的作用机制。方法体外原代培养用酶消化法获得的新生sD大鼠颅盖骨成骨细胞。在培养液中分别加入不同浓度的淫羊藿甙，用RT-PCR法测定成骨细胞BMP-2、Osterix、碱性磷酸酶（ALP）和I型胶原（ColI）mRNA表达。将淫羊藿甙（10ng／m1）与BMP-2单克隆抗体单独或共同加入培养液中，培养48h，用RT—PCR测定成骨细胞OsterixmRNA表达水平的变化。结果1、10、100ng／ml淫羊藿甙均可促进BMP-2、Osterix、ALP和ColImRNA表达（P〈0．05），以10ng／ml组作用最显著。淫羊藿甙和BMP-2单克隆抗体混合组OsterixmRNA表达下调，与淫羊藿甙组比较，差异有统计学意义（P〈0．05），而与BMP-2抗体组比较，差异无统计学意义（P〉0．05）。结论淫羊藿甙能提高成骨细胞中ALP和ColImRNA的表达水平，从而促进成骨细胞增殖与分化，并通过提高BMP-2的表达水平来促进成骨细胞Osterix的基因表达，从而诱导骨形成，发挥抗骨质疏松作用。

Objective To observe the effect of icarrin on proliferation and differentiation of rat osteoblasts cultured in vitro as well as the expressions of bone morphogenetic protein-2 （BMP-2） and Osterix in rat osteoblast. Methods Calvarial osteoblasts were obtained from newborn （ 〈 24 h ） SD rats by trypsin-eollagenase digestion. The culture medium with different icarrin concentrations and the second generation osteoblasts were mixed. The mRNA expressions of BMP-2, Osterix, ALP, and Col I were detected by semiquantative RT-PCR. Then the second generation osteoblasts were cultured in the medium containing ieariin （ 10 ng/ml） with or without BMP-2 antibody. After48 h, RT-PCR was used to estimate the mRNA expression of Osterix. Results In comparison with the control group, the mRNA expressions of BMP-2, Osterix, ALP, Col I were increased in a dose-dependent manner （ P〈0.05 ） with a maximal effect at the concentration of 10 ng/ml. The mRNA expression of Osterix treated with the mixture of icarrin and BMP-2 antibody was significant decreased（ P〈0.05 ）, and compared with the group of icarrin, however, the difference between the BMP-2 group and the mixture group was not statistically significant （P 〉0. 05 ）. Conclusions Icarrin stimulates proliferation and differentiation of cultured osteoblast in vitro by increasing the mRNA expression of ALP and Col I . Iearrin could stimulate Osterix gene expression by enchanting BMP-2 gene expression, finally, it could induce bone formation and prevent and/or treat osteoporosis.