Regenerative medicine for acute lung injury : introduction of EPC

从外周血中分离CD 34阳性细胞。使用含有VEGF、FBS和IGF的EBM-2培养基将这些细胞分化为上皮祖细胞（EPC）。采用ARDS实验模型，用免疫组织化学方法检测内皮细胞表面抗原的动态变化。在博莱霉素诱导的急性肺损伤中，观察到血管增殖。然而，血管增生并没有发生在内毒素诱导的肺损伤。我们研究了咯利普兰（PDE-IV抑制剂），利多卡因，咪达唑仑，异丙酚，氯胺酮（麻醉剂）对肺泡II型肺细胞增殖的影响。Rolipram可促进培养的大鼠II型肺细胞的自发增殖和KGF/HGF诱导的增殖。利多卡因、咪达唑仑、异丙酚、氯胺酮对肺Ⅱ型细胞的自发增殖无明显影响，对KGF/HGF诱导的肺Ⅱ型细胞增殖无明显促进作用。抗Fas抗体诱导的中性粒细胞凋亡是由咯利普兰，而不是由麻醉剂增强。BrdU抗体的免疫组织化学分析显示，咯利普兰增加了KGF/HGF处理的小鼠II型肺细胞的DNA合成。咯利普兰可减轻内毒素所致急性肺损伤的病理改变。咯利普兰的这一成功结果可能是由于药物对肺泡上皮细胞的影响。

CD34-positive cells were isolated from peripheral blood. These cells were differentiated to epithelial progenitor cells (EPC) using EBM-2 medium containing VEGF, FBS, and IGF. Using ARDS experimental model, dynamic change of endothelial cells was immunohistologically assessed by surface antigen. In bleomycin-induced acute lung injury, proliferation of blood vessels was observed. However, vascular proliferation did not occur in endotoxin-induced lung injury. We investigated the effects of rolipram (PDE-IV inhibitor), lidocaine, midazolam, propofol, ketamine (anesthetics) on proliferation of alveolar type II pneumocytes. Rolipram increased spontaneous proliperation and enhanced KGF/HGF-induced proliferation of rat cultured type II pneumocytes. Lidocaine, midazolam, propofol, ketamine had no effect on spontaneous proliperation and enhanced KGF/HGF-induced proliferation of type II pneumocytes. Anti-Fas antibody-induced apoptosis of neutrophils was enhanced by rolipram and not by the anesthetics. Immunohistochemical analysis using BrdU antibody revealed that rolipram increased DNA synthesis in type II pneumocytes in mice treated with KGF/HGF. Rolipram attenuated the pathological changes of the endotoxin-induced acute lung injury. This successful result of rolipram may be due to the effect of the drug on alveolar epithelial cells.