Development of Regenerative Medicine for COPD

将C57 BL/6小鼠的骨髓用GFP转基因重建，并制备GFP嵌合体小鼠。在该嵌合体小鼠中通过LPS产生急性肺损伤，并且通过在LPS滴注1、2或6个月后从肺组织获得单细胞悬液来分析肺细胞。使用几种干细胞标志物进行FACS分析。结果，急性肺损伤后6个月，肺泡壁GFP阳性细胞比例逐渐下降。虽然骨髓源性细胞在急性修复期起主要作用，但慢性期存在的肺内源性干细胞在损伤后的修复过程中显示出相关性。此外，肺内源性干细胞群体中不存在GFP阳性细胞，表明骨髓细胞不是肺内源性干细胞的来源。提示在急性肺损伤的修复过程中，不仅骨髓源性细胞，而且存在的内源性干细胞也起重要作用。然后，研究肺内源性干细胞在肺气肿肺再生模型中的作用。本研究采用弹性蛋白酶诱导的肺气肿中肝细胞生长因子（HGF）诱导的肺再生模型。结果，观察到肺组织中具有干细胞标志物如CD 34的细胞群的数量增加，并且这些细胞对于HGF诱导的受损肺的再生是必需的。此外，阐明了HGF增加这种肺内源性干细胞的数量，并促进这些干细胞群分化为成熟的肺细胞。这些结果正在分子治疗中进行修订。

The bone marrow of the C57BL/6 mouse was reconstituted with GFP-transgenic, and the GFP-chimera mouse was made. The acute lung injury was developed by LPS in this chimera mouse, and the lung cells were analyzed by obtaining single cell suspension from the pulmonary tissue after 1, 2 or 6 months of LPS-instillation. FACS analyses were performed using several stem cell markers. As a result, the ratio of the GFP-positive cells in the alveolar walls gradually decreased at the stage of 6 months after acute lung injury. The endogenous stem cells of existing lungs in the chronic phase shows relations in the repair processes after the injury though the bone marrow-derived cell plays a major role at the acute repair period. Moreover, the GFP-positive cells did not exist in the population of lung endogenous stem cells, suggesting that the bone marrow cells were not a source of lung endogenous stem cells. These data suggested that not only the bone marrow-derived cell but also existing endogenous stem cells were important in repair processes of acute lung injury. Then, the role of the lung endogenous stem cells in the lung regeneration model from pulmonary emphysema was examined. The hepatocyte growth factor (HGF)-induced lung regeneration model in the elastase-induced emphysema was utilized for this study. As a result, increasing the number of cell groups with the stem cell markers such as CD34 in the pulmonary tissue was observed, and these cells were necessary for HGF-induced regeneration of the destroyed lungs. Moreover, it was clarified for HGF to increase the number of such lung endogenous stem cells, and to promote the differentiation of these stem cell groups into the mature lungs cells. These results are being in under revision in the Molecular Therapy.