基于BMP-2/Smads信号通路研究傣族药肾叶山蚂蝗对去卵巢大鼠骨质疏松的保护作用及机制

Effect of Desmodium renifolium on ovariectomized rat model of osteoporosis via BMP-2/Smads signaling pathway

研究傣族药肾叶山蚂蝗对去卵巢大鼠骨质疏松的保护作用及其机制。通过复制去卵巢骨质疏松模型,探讨肾叶山蚂蝗治疗绝经后骨质疏松症(PMOP)的药效和作用机制。大鼠随机分为假手术组,模型组,仙灵骨葆组以及肾叶山蚂蝗低、中、高剂量组。除假手术组切除双侧卵巢周围脂肪组织外,其余各组均行双侧卵巢切除术。术后恢复性饲养2周,假手术组和模型组分别给予等体积的0.5%CMC-Na,仙灵骨葆组和肾叶山蚂蝗各剂量组分别给予仙灵骨葆和不同浓度的肾叶山蚂蝗醇提物,每天灌胃1次,连续14周。实验期间观察体质量变化,实验结束后取血检测血清中雌激素(E_(2))、1,25二羟基维生素D_(3)[1,25(OH)_(2)D_(3)]、钙(Ca)和磷(P)的含量;采用micro-CT技术对股骨骨微结构进行三维分析;实时定量PCR(RT-PCR)检测大鼠胫骨中骨形态发生蛋白2(BMP-2)、核心结合蛋白因子2(Runx2)和成骨细胞特异性转录因子Osterix(OSX)mRNA的表达;蛋白免疫印记法(Western blot)检测大鼠胫骨BMP-2、Runx2和OSX蛋白表达情况。结果显示,肾叶山蚂蝗能显著抑制大鼠体质量的增长,改善子宫外观形态,升高血清E_(2)、Ca、P和1,25(OH)_(2)D_(3)的含量,增加骨小梁的数量并能减少骨小梁断裂,改善骨微结构相关参数,同时能升高大鼠胫骨中BMP-2、Runx2和OSX mRNA和蛋白的表达。以上结果表明,肾叶山蚂蝗能显著改善去卵巢大鼠的骨质疏松,其作用机制可能与调控BMP-2/Smads信号通路相关。

This study aimed to investigate the effect of Desmodium renifolium(Linn.) Schindl on ovariectomized rat model of osteoporosis and explore the underlying mechanism. Rats were randomized into a sham group, a model group, a Xianlin Gubao group, and low-, medium-, and high-dose D. renifolium groups. Bilateral oophorectomy was performed in other groups except sham group(removal of bilateral peri-ovarian adipose tissue). The sham group and model group were administrated with equal volume of 0.5% CMC-Na, Xianlin Gubao group with Xianlin Gubao, and D. renifolium groups with different concentrations of alcoholic extract of D. renifolium once a day for 14 weeks. The body weight of rats were recorded during the experiment. The levels of estradiol(E_(2)), 1,25-dihydroxyvitamin D_(3)[1,25(OH)_(2)D_(3)], calcium(Ca), and phosphorus(P) in serum were determined after the administration. The femur microstructure was analyzed via micro-CT. RT-PCR and Western blot were employed to respectively determine the mRNA and protein levels of bone morphogenetic protein 2(BMP-2), Runt-related transcription factor 2(Runx2), and osterix(OSX) in the tibia of rats. The results indicated that D. renifolium significantly inhibited the weight growth, improved the uterus appearance, elevated the levels of E_(2), Ca, P, and 1,25(OH)_(2)D_(3)in serum, increased the number and reduced the fracture of bone trabeculae, ameliorated the bone microstructure parameters, and up-regulated the mRNA and protein levels of BMP-2, Runx2, and OSX. All the results demonstrated that D. renifolium had significant protective effect on the ovariectomized rat model of osteoporosis by regulating the BMP-2/Smads signaling pathway.