Gazdhar Amiq, Fachinger Patrick, van Leer Coretta, Pierog Jaroslaw, Gugger Mathias, Friis Robert, Schmid Ralph A, Geiser Thomas
Division of Thoracic Surgery, University Hospital, CH-3010 Bern, Switzerland.
Am J Physiol Lung Cell Mol Physiol. 2007 Feb;292(2):L529-36. doi: 10.1152/ajplung.00082.2006. Epub 2006 Oct 20.
Abnormal alveolar wound repair contributes to the development of pulmonary fibrosis after lung injury. Hepatocyte growth factor (HGF) is a potent mitogenic factor for alveolar epithelial cells and may therefore improve alveolar epithelial repair in vitro and in vivo. We hypothesized that HGF could increase alveolar epithelial repair in vitro and improve pulmonary fibrosis in vivo. Alveolar wound repair in vitro was determined using an epithelial wound repair model with HGF-transfected A549 alveolar epithelial cells. Electroporation-mediated, nonviral gene transfer of HGF in vivo was performed 7 days after bleomycin-induced lung injury in the rat. Alveolar epithelial repair in vitro was increased after transfection of wounded epithelial monolayers with a plasmid encoding human HGF, pCikhHGF [human HGF (hHGF) gene expressed from the cytomegalovirus (CMV) immediate-early promoter and enhancer] compared with medium control. Electroporation-mediated in vivo HGF gene transfer using pCikhHGF 7 days after intratracheal bleomycin reduced pulmonary fibrosis as assessed by histology and hydroxyproline determination 14 days after bleomycin compared with controls treated with the same vector not containing the HGF sequence (pCik). Lung epithelial cell proliferation was increased and apoptosis reduced in hHGF-treated lungs compared with controls, suggesting increased alveolar epithelial repair in vivo. In addition, profibrotic transforming growth factor-beta1 (TGF-beta1) was decreased in hHGF-treated lungs, indicating an involvement of TGF-beta1 in hHGF-induced reduction of lung fibrosis. In conclusion, electroporation-mediated gene transfer of hHGF decreases bleomycin-induced pulmonary fibrosis, possibly by increasing alveolar epithelial cell proliferation and reducing apoptosis, resulting in improved alveolar wound repair.
肺泡伤口修复异常会导致肺损伤后肺纤维化的发展。肝细胞生长因子（HGF）是一种对肺泡上皮细胞有强大促有丝分裂作用的因子，因此可能在体外和体内改善肺泡上皮修复。我们假设HGF可在体外增加肺泡上皮修复，并在体内改善肺纤维化。使用转染了HGF的A549肺泡上皮细胞的上皮伤口修复模型来测定体外肺泡伤口修复情况。在大鼠博来霉素诱导的肺损伤7天后，进行电穿孔介导的HGF体内非病毒基因转移。与培养基对照相比，用编码人HGF的质粒pCikhHGF（从巨细胞病毒（CMV）立即早期启动子和增强子表达的人HGF（hHGF）基因）转染受伤上皮单层后，体外肺泡上皮修复增加。与用不含HGF序列的相同载体（pCik）处理的对照相比，经气管内给予博来霉素7天后使用pCikhHGF进行电穿孔介导的体内HGF基因转移，在博来霉素给药14天后通过组织学和羟脯氨酸测定评估，可减少肺纤维化。与对照相比，hHGF处理的肺中肺上皮细胞增殖增加且细胞凋亡减少，表明体内肺泡上皮修复增加。此外，hHGF处理的肺中促纤维化转化生长因子-β1（TGF-β1）减少，表明TGF-β1参与了hHGF诱导的肺纤维化减轻。总之，电穿孔介导的hHGF基因转移可减少博来霉素诱导的肺纤维化，可能是通过增加肺泡上皮细胞增殖和减少细胞凋亡，从而改善肺泡伤口修复实现的。
