女贞子、蛇床子药对激活ERα36-MAPKs-Ca2+/NFATc1信号通路调控破骨细胞线粒体能量合成和破骨细胞凋亡的机制研究

Postmenopausal osteoporosis (POP) causes great challenge to the health in middle and aged women as well as the family and society. The herbal pair of glossy privet fruit and fructus cnidii from Tonifying kidney herbs represents one of the effective constitutions in treating POP by the instruction of “Mutual rooting of Yin Yang” theory in Traditional Chinese medicine (TCM). Our previous investigations have well established that this herbal pair can inhibit the bone resorption activity of osteoclast by activating estrogen receptor (ER) α36. However, the exact role of this herb pair in regulating ERα36-MAPKs-Ca2+/NFATc1 signaling activited energy synthesis in mitochondrial and apoptosis of osteoclasts are still not investigated. Therefore, we sought to fully establish the effect of herbal pair of glossy privet fruit and fructus cnidii in regulating the mitochondrial energy synthesis and apoptosis of osteoclast. Our hypothesis is verified based on that this herbal pair activate ERα36-MAPKs-Ca2+/NFATc1 signaling pathway through animal model, primary osteoclast culture and SiERα36 approaches. Our study will fully establish the mechanisms of this herbal pair as well as the effective components of Oleanolic acid and osthole in treating POP by down regulates the energy synthesis in mitochondria, the activity of osteoclast and promotes the apoptosis of osteoclast as well as inhibits osteoclastic bone repsorption. Our work wills gain new insights into drugs discovery in treating POP as well as broadening our biological understanding of“Mutual rooting of Yin Yang” theory in TCM.

绝经后骨质疏松症（POP）严重威胁中老年女性的健康，给家庭和社会带来沉重的负担。补肾中药女贞子、蛇床子药对是在中医“阴阳互根”理论指导下形成的治疗POP的有效药对。团队前期研究发现该药对能够激活雌激素受体ERα36，抑制破骨细胞的骨吸收，但是其对ERα36-MAPKs-Ca2+/NFATc1信号通路调控破骨细胞线粒体能量合成和破骨细胞凋亡的作用尚未阐述。本项目拟从ERα36-MAPKs-Ca2+/NFATc1信号通路着手，应用ERα敲除动物模型、去卵巢动物模型、原代细胞培养、siERα36等技术，阐明该药对及有效组分齐墩果酸、蛇床子素激活ERα36-MAPKs-Ca2+/NFATc1信号通路、抑制破骨细胞线粒体能量合成、抑制破骨细胞的活性、诱导破骨细胞的凋亡和降低骨吸收活性的机制，为防治POP提供新的分子生物学机制，丰富和发展“阴阳互根”理论的科学内涵。

绝经后骨质疏松症（POP）严重威胁中老年女性的健康，给家庭和社会带来沉重的负担。遵循中医“肾主骨”等理论的指导，临床广泛应用补肾法则治疗POP，而女贞子、蛇床子药是中医临床治疗POP的常见组合。本研究在前期研究明确该药对延缓骨丢失的基础上，继续阐述两者能激活雌激素受体非经典受体ERα36，发挥骨保护的作用机制。本研究发现激活ERα36-MAPKs-Ca2+/NFATc1信号通路,降低调控破骨细胞线粒体能量合成，诱导破骨细胞凋亡，降低破骨细胞的骨吸收功能。同时，研究发现女贞子、蛇床子药对破骨细胞的生成未见明显抑制作用，但是明显诱导成熟破骨细胞的凋亡，其主要机制是激活破骨细胞内的ERα36.-MAPKs-Ca2+/NFATc1信号通路，从而抑制破骨细胞线粒体能量合成和抑制骨吸收。小鼠实验表明敲除ERα后，小鼠出现骨丢失的表型，破骨细胞凋亡的降低，骨吸收增加。而女贞子、蛇床子药对干预后，破骨细胞凋亡的增加，骨吸收降低。表明女贞子、蛇床子药对调控破骨细胞的作用与选择性雌激素受体（SERMs）调控的作用类似。分子机制上，两者能够女贞子、蛇床子药对激活ERα36调控的MAPKs及其下游的 Ca2+/NFATc1表达，从而降低破骨细胞的线粒体能量合成，破坏其细胞骨架和稳态，诱导凋亡。本研究阐述女贞子、蛇床子药对抑制破骨细胞的活性、诱导破骨细胞的凋亡和降低骨吸收活性的机制，并明确其雌激素样作用的机制，为防治POP提供新的分子生物学机制，并同时临床治理POP新的药物开发提供分子机制。