脂肪干细胞3D微组织治疗压力性尿失禁的效果及机制研究

The morbidity of stress urinary incontinence (SUI) is up to 40% in middle and old age women, which is the most common type of urinary incontinence and seriously endanger women's health. Current SUI treatment methods can not effectively restore the physiological and pathological changes of pelvic floor muscle and urethra smooth muscle. Adipose-derived stem cells (ADSC) can be easily isolated and have lots of sources, and autologous transplantation has no ethic problems, which has become an important source of seed cells in clinical practice. The low retention rate of stem cells in the lesions, to some extent, has limited the therapeutic effects of stem cells' local injection. In the earlier study, applicants solved the problem of retention of stem cells, using ADSC to spontaneously form a three dimensional micro tissues (3D-MTs) structure. The aim of this study is to establish an ideal SUI rat model, trace the dynamic changes of 3D-MTs (labelled with EdU and GFP) in the body to prove its therapeutic efficacy and advantages in treating SUI rat model, and verify the molecular mechanism of 3D-MTs treatment for SUI through monitoring stem cell activation and migration-related signaling pathways (wnt/β-catenin pathway, BMP pathway, Notch pathway and CXCR4/SDF-1 axis). This project will provide a new theoretical basis and technical support for stem cell treatment for SUI.

压力性尿失禁（SUI）在经产及高龄妇女中发病率高达40%,严重危害女性健康和生活质量。目前SUI的治疗方法均不能从组织和功能上恢复盆底肌及尿道病理变化。脂肪干细胞（ADSC）来源丰富取材简单，自体移植没有伦理学问题，为治疗SUI带来新契机。申请者前期研究中，利用ADSC三维微组织（3D-MTs）解决了常规ADSC局部注射干细胞滞留率的问题。本研究拟通过建立分娩/球囊扩张/卵巢切除和双侧阴部神经离断SUI大鼠模型，利用经EdU和GFP标记过的3D-MTs治疗SUI大鼠，跟踪其在体内动态变化，证明3D-MTs在SUI模型中的治疗效果及其优势；并通过监测干细胞激活和迁移相关信号通路（wnt/β-catenin信号通路、BMP信号通路、Notch信号通路和CXCR4/SDF-1轴）的变化，探明3D-MTs治疗SUI的分子机制。本项目将为干细胞治疗SUI提供新的理论依据和技术支持。

压力性尿失禁是指腹压突然增高时，在不伴有逼尿肌收缩的情况下尿液的非随意性溢出，是最常见的尿失禁类型。其发病机制包括盆底及尿道周围横纹肌松弛，阴道前壁脱垂，尿道长度缩短，尿道平滑肌张力减退，膀胱颈及尿道位置降低使尿道倾斜角增大，膀胱尿道后角消失。目前压力性尿失禁的治疗方法主要包括非手术治疗和手术治疗两大类。最常用的手术治疗方法是无张力吊带法。非手术治疗主要是指各种盆底复健的方法，如盆底肌肉训练、盆底生物反馈治疗、口服药物治疗、以及局部注射填充剂疗法等。近年来，研究发现脂肪干细胞可以通过使有缺陷的尿道周围肌肉及结缔组织得以再生，从而替代、修复和增强压力性尿失禁患者盆底及尿道周围受损的组织和器官的生物功能，达到彻底治愈压力性尿失禁的目的。为提高干细胞在病变部位的滞留率，使干细胞充分发挥修复与抗损伤作用，采用悬吊法体外培养脂肪干细胞，可在不借助其它组织工程材料的情况下，在体外实现脂肪干细胞的自聚集，形成三维立体的微组织。结果显示，脂肪干细胞三维立体培养与普通常规培养相比，可显著提高营养因子如神经营养因子、血管生长因子的表达量，并且显著提高压力性尿失禁模型鼠的漏尿点压力和膀胱容量。