elastin基因修饰的BMSCs在bFGF纳米缓释系统诱导下注射治疗盆底功能障碍性疾病的实验研究

Pelvic floor dysfunction (PFD) is a common gynecological disease. Traditional surgery or using graft to reconstruct pelvic floor has its limitations. Studies show a close relationship between collagen as well as elastin in pelvic support structure and PFD. The application of bone marrow mesenchymal stem cells (BMSCs) to promote tissue regeneration and repair of the pelvic floor shows promising results to the treatment of PFD. The key to this new treatment is to increase BMSCs’capability of differentiation to fibroblast and facilitate the secretion of collagen and elastin by fibroblast. Our previous study found that platelet-rich plasma (PRP) gel can not only be used as scaffold for BMSCs but also can improve the cell adherence and proliferation. Basic fibroblast growth factor (bFGF) can act as cytokine to induce BMSCs. The controlled release nano- microspheres invented in our previous study can effectively stabilize and release bFGF slowly. In this study, to improve BMSCs’ the capability of differentiation to fibroblast and facilitate the secretion of collagen and elastin by fibroblast, the elastin gene modified BMSCs will be mixed with PRP gel and injected into the weak spot of rat PFD model together with the bFGF encapsulated in the controlled release nano- microspheres by the stirring syringe invented by us, which will help the generated fibroblast to secrete collagen and elastin and then ultimately enhance the pelvic floor tissue regeneration and repair. This therapy could provide a new none-invasive treatment on the PFD.

盆底支持结构中胶原蛋白和弹性蛋白的减少是盆底功能障碍性疾病（PFD）发生的关键因素。理论上，骨髓间充质干细胞（BMSCs）可促进盆底组织的再生和修复，使PFD注射治疗成为可能，但需提高BMSCs局部生存和分化为成纤维细胞并促进其分泌胶原蛋白和弹性蛋白的能力。我们前期研究证实富血小板血浆（PRP）凝胶可作为BMSCs的支架，同时有利于细胞的粘附和增殖。为长期提高BMSCs有效分化为成纤维细胞，课题组成功研制了能长期平稳释放bFGF的纳米缓释系统。在前期研究基础上，本研究拟进一步以elastin基因转染BMSCs，在PRP凝胶条件下，与包封bFGF的纳米缓释微粒一起，通过自主研制的搅拌注射器混匀并注射至PFD大鼠模型的盆底薄弱部位，使薄弱部位生成的成纤维细胞大量分泌胶原蛋白，同时亦能较多分泌弹性蛋白，并最终促进盆底支持组织的再生和修复，为PDF的早期、微创治疗提供新的途径。

盆底支持结构中成纤维细胞分泌的胶原蛋白和弹性蛋白的减少是盆底功能障碍性疾病（PFD）发生的关键因素。应用骨髓间充质干细胞（BMSCs）来促进受损组织的再生和修复是治疗PFD的理想方法。故在本项目中，我们通过系列方法，来确保BMSCs能在局部生存和分化为成纤维细胞并高效分泌胶原蛋白和弹性蛋白，从而最终促进盆底支持组织的再生和修复。. 课题组首先以Elastin基因转染BMSCs，使BMSCs在分泌胶原蛋白同时亦能分泌较多的弹性蛋白；而后，我们应用bFGF作为生长因子来促进BMSCs增殖和定向分化为成纤维细胞。并且将bFGF包封在课题组自行研制的纳米缓释微粒中，以达到使bFGF在局部长期、高效释放的目的，从而提高了BMSCs在体内的分化效能；再次，我们将Elastin基因转染的BMSCs与包封bFGF的纳米缓释系统混合，通过自主研制的搅拌注射器混匀并注射至PFD大鼠模型的盆底薄弱部位，使薄弱部位新生成的成纤维细胞分泌胶原蛋白和弹性蛋白的能力大大增强，并最终证明该手段能有效促进盆底支持组织的再生和修复。. 此后，为进一步探明BMSCs中Elastin表达的调控机制，我们确定了miR-29a-3p可与Elastin基因mRNA上的3’UTR结合从而抑制其表达。因此，课题组将anti-miR-29转染BMSCs以构建Elastin高表达的BMSCs，并将其与bFGF纳米缓释系统混合，应用于PFD大鼠模型的治疗，同样也取得了显著成效。. 上述研究成果均提高了BMSCs再生和修复盆底薄弱和缺损组织的能力，为临床早期、微创治疗PFD提供了新的思路和途径。