CD34抗体修饰的Smad7-壳聚糖纳米颗粒通过调控内皮细胞间质化途径抑制异位骨化症的实验研究

Endothelial-mesenchymal transition(EndMT) is an important pathological mechanismof heterotopic ossification(HO),and TGF-β signal transduction pathway is recognized as the main signal transduction pathway in this disease.Our research team has proved that EndMT as well as HO could be inhibited by over-expression of Smad-7 gene which exists in the TGF-β signal transduction pathway in the previous.study. So we put forward the following hypothesis : EndMT and HO in the local tissue could be inhibited by the combinated construction of nano chitosan particle and Smad-7 pDNA which is modified by CD-34 antibody on the surface.This study intends to validate the hypothesis preliminary by in vivo and in vitro experiments,also further discuss the mutual interaction and molecular mechanism between T-tGFβ and EndMT as well as HO in level of In cells, tissues and animals,including the downstream signal and special miRNA of TGF-β signal transduction pathway.The proposed study will clarify the molecular mechanism of HO and lead to new strategy for prevention and treatment of HO.

内皮细胞向间充质细胞转化（Endothelial-mesenchymal transition,EndMT）途径是异位骨化症（HO）重要的病理机制，而转化生长因子-β（TGF-β）信号传导途径是其公认的主要信号通路。本课题组在前期试验中证实促进TGF-β信号通路中的Smad-7基因表达上调，可有效抑制EndMT途径，阻滞HO进展。因此我们提出如下假说：采用纳米壳聚糖颗粒作为Smad-7基因载体，CD34抗体作为配体构建的Smad-7pDNA/壳聚糖纳米颗粒，能够在组织局部显著抑制EndMT和HO的进展。本研究拟通过体内和体外实验初步验证该假说，同时也在细胞、组织和动物水平进一步探讨TGF-β信号通路和EndMT途径以及HO三者之间的相互作用及其分子机制，包括影响TGF-β信号途径的下游信号通路和特定miRNA等。通过本研究将进一步明确HO的分子病理机制，为临床防治工作提供新的思路。

异位骨化症（HO）是一种引起广泛疼痛和功能障碍的疾病，其特征是受伤后骨骼外系统的骨异位形成。超磁性氧化铁（SPIO）纳米颗粒疗法已广泛用于各种骨科疾病。但是，SPIO纳米颗粒对HO的治疗仍然未知。在研究中，我们准备了携带SMAD7基因的SPIO纳米颗粒,并评估了它们在大鼠模型中对HO的机制功能。结果表明，含有SMAD7处理的SPIO纳米颗粒导致体外上皮-间质转化（EndMT）相关蛋白表达降低。此外，SPIO纳米颗粒标记EPCs移植可有效预防HO大鼠异位骨化并抑制内皮-间质转化（EndMT）。同时，SPIO纳米颗粒标记的EPCs移植抑制了胚胎成纤维细胞的成骨和成脂分化（EFs）在HO大鼠中。我们的研究结果表明，用SPIO纳米颗粒标记的EPC可以抑制大鼠体内的HO，这可能是临床上可能会进行医学干预的潜在治疗方法。