雌激素水平降低和雌激素受体(ER)信号通路异常是绝经后骨质疏松症发病的主要原因。miRNA在骨代谢中发挥着重要作用，但其介导ER信号通路调控骨代谢的作用机制尚不清楚。前期研究发现，中药单体槲皮素(QUE)能够激活MAPK、Wnt和ER信号通路促进骨髓间充质干细胞(BMSCs)骨向分化，故得出QUE是通过某些miRNA介导ER信号通路来调控骨代谢的假说。因此，本课题以ER信号通路作为切入点，以ER基因敲除小鼠及ER基因沉默BMSCs作为研究媒介，结合体内和体外实验，采用Micro CT、QPCR、Western-blot和miRNA基因芯片等技术，观察ER阻断及QUE干预后骨代谢的变化并筛选相关miRNA，以明确与ER信号通路密切相关的miRNA，以及miRNA如何介导ER信号通路在QUE促骨形成过程中发挥调控作用。该项目为QUE防治骨质疏松症等骨性疾病提供了理论支持，具有很好的科学意义。

The decrease of estrogen and the dysfunction of estrogen receptor(ER) is the main cause of postmenopausal osteoporosis (PMOP). At present, many studies have confirmed that, microRNA(miRNA) play an important role in the regulation of osteoblast differentiation and bone formation, but the osteogenic related expression patterns of miRNA and the specific mechanism is not clear. Our previous study found that quercetin (QUE) could promote BMSCs osteogenic differentiation, but through which miRNA mediating estrogen receptor (ER) signaling pathway to regulate the bone metabolism pathway is unclear. Therefore, this project is based on the osteogenic differentiation of QUE as a research platform, the ER signaling pathway as a entry point, ER gene knockout mice and ER gene silencing of BMSCs as the study of media, combined with in vivo and in vitro experiments, by using the technology of the Micro CT, QPCR, Western-blot and miRNA gene microarray technique, to observe the change of bone metabolism and related miRNA after ER blocking and QUE intervention, to clear the specific regulation of ER signaling pathway and the relationship with miRNA in the process of bone formation of QUE. The project provides theoretical support for QUE in preventing and treating bone disease such as OP, has the good theoretical value and application value.