Department of Medical Ultrasound, Qingdao Municipal Hospital (Group), Qingdao, 266000, Shandong, China.
Department of Medical Ultrasound, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, 100 Haining Rd., Shanghai, 200080, China.
Stem Cell Res Ther. 2020 Apr 3;11(1):145. doi: 10.1186/s13287-020-01655-1.
BACKGROUND/AIMS: Bone marrow mesenchymal stem cells (BMSCs) have shown their therapeutic potential in cytotherapy for liver fibrosis. However, the insufficient homing of BMSCs and undefined proliferation of BMSCs represent a significant challenge and largely limit the effective implementation. The aims of the present study were to determine whether stable expression of hepatic growth factor (HGF) in BMSCs coupled with ultrasound-targeted microbubble destruction (UTMD) technique could effectively and definitely alleviating carbon tetrachloride (CCl4)-induced liver fibrosis in rats.
A rat model of liver fibrosis was acquired by injection of carbon tetrachloride (CCl4). The experimental rats were randomly assigned to the four groups: normal, CCl4, BMSCs-HGF/US, and BMSCs-HGF/UTMD groups. The BMSCs, transfected by recombinant adeno-associated virus vector encoding human genome sequence of HGF (BMSCs-HGF), were transplanted in rat via the tail vein. The homing efficiency of BMSCs was observed by immunofluorescence staining. The liver function and its morphological changes were analyzed by biochemical tests and liver histology. The expression of liver fibrosis markers including α-smooth muscle actin (α-SMA), collagen I, and vimentin were examined by immunohistochemistry and quantitative real-time polymerase chain reaction.
The homing efficiency of BMSCs in the fibrotic liver was significantly greater with the application of UTMD. The biochemical markers of liver function and histopathological results showed significantly better improvement in BMSCs-HGF/UTMD group than the other groups, and the serum levels of biochemical markers returned to normal ranges in 12 weeks in this group. Furthermore, the expression levels of liver fibrosis markers (α-SMA, collagen I, and Vimentin) were all significantly lower in BMSCs-HGF/UTMD group in comparison with other groups.
Our findings have demonstrated that stable expression of HGF in BMSCs and application of the UTMD technique facilitate the homing of BMSCs, and more importantly, which could further improve their alleviation of liver fibrosis. Therefore, these findings have an important clinical implication that AAV-BMSCs-HGF and UTMD hold promise as a novel therapeutic approach for liver fibrosis.
背景/目的：骨髓间充质干细胞（BMSCs）在肝纤维化的细胞治疗中显示出了治疗潜力。然而，BMSCs 的归巢不足和增殖未定义仍然是一个重大挑战，在很大程度上限制了其有效实施。本研究旨在确定 BMSCs 中稳定表达肝细胞生长因子（HGF）并结合超声靶向微泡破坏（UTMD）技术是否能有效且明确地缓解大鼠的四氯化碳（CCl4）诱导的肝纤维化。
通过注射四氯化碳（CCl4）建立大鼠肝纤维化模型。实验大鼠被随机分为四组：正常组、CCl4 组、BMSCs-HGF/US 组和 BMSCs-HGF/UTMD 组。通过尾静脉将转染了重组腺相关病毒载体编码的人基因组序列 HGF（BMSCs-HGF）的 BMSCs 移植到大鼠体内。通过免疫荧光染色观察 BMSCs 的归巢效率。通过生化试验和肝组织学分析检测肝功能及其形态变化。通过免疫组化和实时定量聚合酶链反应检测肝纤维化标志物，包括α-平滑肌肌动蛋白（α-SMA）、胶原 I 和波形蛋白的表达。
应用 UTMD 后，BMSCs 在纤维化肝脏中的归巢效率显著增加。BMSCs-HGF/UTMD 组的肝功能生化标志物和组织病理学结果均有明显改善，12 周时血清生化标志物水平恢复正常。此外，与其他组相比，BMSCs-HGF/UTMD 组的肝纤维化标志物（α-SMA、胶原 I 和波形蛋白）表达水平均显著降低。
本研究结果表明，BMSCs 中 HGF 的稳定表达和 UTMD 技术的应用促进了 BMSCs 的归巢，更重要的是，这可以进一步改善它们对肝纤维化的缓解作用。因此，这些发现具有重要的临床意义，即 AAV-BMSCs-HGF 和 UTMD 有望成为肝纤维化的一种新的治疗方法。
