SDF-1/CXCR4介导羊膜间充质干细胞归巢修复卵巢功能的研究

Stem cell therapy，especially mesenchymal stem cells transplantation have been proved to improve the ovarian function in Premature Ovarian Failure(POF) model. Our preliminary experiment suggested human Amniotic Mesenchymal Stem Cells (AMSCs) refined ovarian function of POF mice. However, some problems have also been reported, such as its limited number of stem cells in targeted area due to the systemic and pulmonary circulation. At present, researches have confirmed that the SDF-1/CXCR4 axis is an important pathway of stem cells migration and homing to damaged region, such as myocardial infarction, acute kidney injury, lung epithelial injury, brain infarcts and so on. Therefore, we hypothesized that SDF-1/CXCR4 axis also mediate AMSCs homing to ovarian tissue in POF model. To exclude the damage of whole body, we first refine POF model by X-irradiation only at the ovary site, then detect the changes of secretion and distribution of SDF-1 both in serum and ovaries. Sodium Valproate (VPA) is employed to increase CXCR4 expression in AMSCs, while AMD3100, an antagonist of CXCR4 is used to block its expression. To test the hypothesis, AMSCs pretreated with VPA, AMD3100/VPA and non-treatment control are transplanted to POF mice by vein, as well as co-cultured with granulocytes in vitro. This study may provide a theoretical basis for the “stem cell homing to ovary” hypothesis, and further explore the clinical application of AMSCs treatment curative effect and mechanism of POF.

间充质干细胞移植后可改善小鼠卵巢早衰的卵巢功能，我们前期研究发现人羊膜间充质干细胞（Amniotic Mesenchymal Stem Cells，AMSCs）经静脉移植可改善卵巢功能，卵巢间质内存在少量移植细胞，但许多问题急待明确：AMSCs如何归巢进入卵巢、如何降低体循环吞噬细胞、如何提高移植细胞存活率等。研究表明SDF-1/CXCR4轴介导了干细胞向心肌梗死、脑梗死灶等部位的归巢。我们假设：SDF-1/CXCR4轴参与介导AMSCs向卵巢早衰的卵巢组织的归巢进而改善卵巢功能。本研究采用卵巢定点照射法构建小鼠卵巢早衰模型，检测SDF-1的分泌变化；利用丙戊酸钠促进AMSCs中CXCR4表达、CXCR4拮抗剂AMD3100阻断其表达；并在体内移植及体外与颗粒细胞共培养验证SDF-1/CXCR4是否为介导AMSCs向卵巢归巢的主要通路，为进一步探索临床疗效及机制提供理论据。

间充质干细胞移植可改善小鼠卵巢早衰的卵巢功能，我们前期研究发现人羊膜间充质干 细胞(Amniotic Mesenchymal Stem Cells，AMSCs)经静脉移植可改善卵巢功能，卵巢间质内存在少量移植细胞，但AMSCs如何归巢进入卵巢等尚不明确。研究表明SDF-1/CXCR4轴介导了干细胞向心肌梗死、脑梗死灶等部位的归巢。故本研究假设:SDF-1/CXCR4轴参与介导AMSCs向卵巢组织的归巢进而改善卵巢功能。本研究首先建立了人羊膜间充质干细胞库，并建立了临床级的质量检测标准，为后续实验及临床转化奠定了良好的基础；采用X射线照射法构建小鼠放疗致卵巢早衰模型，并检测SDF-1在卵巢组织中表达上升，但差异无统计学差异; 丙戊酸钠能促进AMSCs中CXCR4表达、并能促进AMSCs增殖及分化及迁移能力，CXCR4拮抗剂AMD3100阻断上述改变;在体外AMSCs与颗粒细胞共培养发现VPA处理后AMSCs向颗粒细胞趋化能力增加，从而验证了SDF-1/CXCR4可能是介导AMSCs向卵巢归巢并改善卵巢功能的机制之一，为进一步探索临床疗效及机制提供理论据。