母-胎界面RANKL调节滋养细胞生物学行为的分子机制

RANKL is a member of tumor necrosis factor superfamily, and it is involved in many physiological and pathological processes, such as bone remodeling, lymph node formation, thymus development, formation of lactating mammary glands, promoting tumorigenesis and bone metastases, controlling fever, and so on. Our recent study found that RANKL and its receptor RANK were expressed in villi and trophoblasts in human early pregnancy, and RANKL promoted the proliferation and invasion of trophoblasts. But the molecular mechanism of RANKL which regulates the biological behavior of trophoblasts is unclear. The project is based on the expression of RANKL at the maternal-fetal interface. We apply real time quantitative PCR, Transwell chamber, plasmid transfection, SiRNA interference and western blotting to explore whether RANKL regulates trophoblasts invasion through PI3K/Akt, Erk or NF-κB signaling pathway. In addition, RANKL knockout mice are used to study the effect of RANKL on embryo implantation. This research is beneficial to clarify the effect of RANKL on trophoblasts invasion and its molecular mechanism, which will provide the theoretical foundation of trophoblastic diseases such as spontaneous abortion.

RANKL是肿瘤坏死因子（TNF）配体超家族成员，参与多种生理病理过程，如骨重塑、淋巴结形成、胸腺发育、孕期乳腺发育、促进肿瘤的发生和骨转移及中枢体温调节等。本课题组前期研究发现人早孕期绒毛组织及滋养细胞表达RANKL及其受体RANK，并且RANKL促进滋养细胞的增殖及侵袭，但RANKL调节滋养细胞生物学行为的分子机制尚不清楚。本课题拟以RANKL在母-胎界面的表达为切入点，应用实时定量PCR、Transwell小室、质粒转染、SiRNA干扰及western blot技术，探讨RANKL是否通过PI3K/Akt、Erk或NF-κB信号通路，进而调节滋养细胞的侵袭等生物学行为；并利用RANKL基因敲除小鼠研究RANKL在胚胎着床及滋养细胞侵袭中的作用。通过本项目研究有利于阐明RANKL对滋养细胞侵袭能力的调控作用及其分子机制，将为滋养细胞疾病如自然流产等发病机理的研究提供理论基础。

RANKL是肿瘤坏死因子（TNF）配体超家族成员，参与多种生理病理过程，如骨重塑、淋巴结形成、胸腺发育、孕期乳腺发育、促进肿瘤的发生和骨转移及中枢体温调节等。本课题组首次发现人早孕期滋养细胞表达RANKL、蜕膜巨噬细胞高表达RANK。因此本课题组以RANKL调节蜕膜巨噬细胞的分化功能为切入点，首先模拟母-胎界面微环境，将滋养细胞、蜕膜基质细胞中及蜕膜巨噬细胞共培养，发现滋养细胞及蜕膜基质细胞来源的RANKL可诱导蜕膜巨噬细胞向M2型方向分化，但其分子机制尚不明确。我们通过实验进一步表明母-胎界面来源的RANKL可通过活化STAT6信号通路，进而诱导巨噬细胞向M2型方向分化，并且RANKL训导过的蜕膜巨噬细胞可诱导蜕膜naïve T细胞向Th2型方向分化，有利于妊娠维持。我们进一步通过动物实验进行了验证，发现RANKL表达水平降低可增加胚胎吸收率，导致流产的发生。敲除正常妊娠小鼠的巨噬细胞可导致流产的发生，过继转输RANK+巨噬细胞可改善妊娠结局。本项目研究表明RANKL在调控蜕膜巨噬细胞分化及功能方面发挥重要作用，将为复发性流产的治疗提供新的治疗方向及思路。