Yang Jia, Zhou Cheng-Zhi, Zhu Rui, Fan Heng, Liu Xing-Xing, Duan Xue-Yun, Tang Qing, Shou Zhe-Xing, Zuo Dong-Mei
Department of Integrated Chinese and Western Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Department of Cardiology, The Affiliated Hospital of Hubei University of Traditional Chinese Medicine, Wuhan, China.
J Gastroenterol Hepatol. 2017 Dec;32(12):1966-1974. doi: 10.1111/jgh.13797.
Epithelial-mesenchymal transition (EMT), characterized by the decrease of E-cadherin (E-Cad) and increase in vimentin and alpha-smooth muscle actin (α-SMA), was demonstrated to participate in inflammatory bowel disease-related fibrosis. miR-200b plays an anti-fibrosis role in inhibiting EMT by targeting ZEB1 and ZEB2. But the stability of exogenous miR-200b in blood limits its application. Microvesicles (MVs), which can transfer miRNAs among cells and prevent them from degradation, may provide an excellent transport system for the delivery of miR-200b in the treatment of fibrosis.
Bone marrow mesenchymal stem cells (BMSCs) were transfected with lentivirus to overexpress miR-200b. The MVs packaged with miRNA-200b were harvested for the anti-fibrotic treatment using in vitro (transforming growth factor beta 1-mediated EMT in intestinal epithelial cells: IEC-6) and in vivo (TNBS-induced intestinal fibrosis in rats) models. The pathological morphology was observed, and the fibrosis related proteins, such as E-Cad, vimentin, α-SMA, ZEB1, and ZEB2, were detected.
MiR-200b-MVs would significantly reverse the morphology in TGF-β1-treated IEC-6 cells and improve the TNBS-induced colon fibrosis histologically. The treatment of miR-200b-MVs increased miR-200b levels both in the IEC-6 cells and colon, resulting in a significant prevention EMT and alleviation of fibrosis. The expression of E-Cad was increased, and the expressions of vimentin and α-SMA were decreased. ZBE1 and ZEB2, the targets of miR-200b, were also decreased.
miR-200b could be transferred from genetically modified BMSCs to the target cells or tissue by MVs. The mechanisms of miR-200b-MVs in inhibiting colonic fibrosis were related to suppressing the development of EMT by targeting ZEB1and ZEB2.
上皮-间质转化（EMT）的特征是E-钙黏蛋白（E-Cad）减少，波形蛋白和α-平滑肌肌动蛋白（α-SMA）增加，已证实其参与炎症性肠病相关纤维化。miR-200b通过靶向锌指E盒结合蛋白1（ZEB1）和锌指E盒结合蛋白2（ZEB2）在抑制EMT中发挥抗纤维化作用。但外源性miR-200b在血液中的稳定性限制了其应用。微泡（MVs）可在细胞间传递微小RNA（miRNAs）并防止其降解，可能为miR-200b在纤维化治疗中的递送提供一个良好的运输系统。
用慢病毒转染骨髓间充质干细胞（BMSCs）以过表达miR-200b。收集包装有miRNA-200b的MVs，用于体外（转化生长因子β1介导的肠上皮细胞EMT：IEC-6细胞）和体内（三硝基苯磺酸诱导的大鼠肠道纤维化）模型的抗纤维化治疗。观察病理形态，并检测纤维化相关蛋白，如E-Cad、波形蛋白、α-SMA、ZEB1和ZEB2。
miR-200b-MVs可显著逆转经转化生长因子-β1处理的IEC-6细胞的形态，并在组织学上改善三硝基苯磺酸诱导的结肠纤维化。miR-200b-MVs处理可提高IEC-6细胞和结肠中的miR-200b水平，从而显著预防EMT并减轻纤维化。E-Cad的表达增加，波形蛋白和α-SMA的表达降低。miR-200b的靶标ZBE1和ZEB2也降低。
miR-200b可通过MVs从基因修饰的BMSCs转移至靶细胞或组织。miR-200b-MVs抑制结肠纤维化的机制与通过靶向ZEB1和ZEB2抑制EMT的发展有关。
