Role of matrix metalloproteinase-2 in bleomycin-induced pulmonary fibrosis

基质金属蛋白酶-2在博莱霉素诱导的肺纤维化中的作用

基本信息

批准号：
12670582
负责人：
FUKUDA Yuh
金额：
$ 2.3万
依托单位：
Nippon Medical School
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12670582/
关键词：
MMP-2 KO mice bleomycin alveolar epithelial cells migration of epithelial cells intraalveolar fiborsis alveolar bronchiolization gelatin zymography 非特異的間質性肺炎器質化肺炎上皮基底膜

项目摘要

Fibrosis in interstitial pneumonia is usually formed in intraalveolar spaces and covered by regenerated alveolar or bronchogenic epithelial cells. In addition to that, activated MMP-2 is suggested to be important to the process of alveolar repair in interstitial pneumonia and the alveolization in fetal lungs. In this context, we investigated the bleomycin lungs in MMP-2 KO and wild mice. After intratracheal administration of bleomycin to mice, animals were sequentially sacrificed. Electron microscopic studies and immunohistochemistry for MMP-2, keratin, PCNA, fibronectin were performed. The degree of fibrosis was quantified by Ashcroft's method and the amount of hydroxyproline in lung tissues. Active form of MMP-2 of lung homogenates was analyzed with Western blotting and gelatin zymography. Degree of fibrosis was similarly observed in both KO and wild mice. Type II alveolar epithelial cell coverage on intraalveolar fibrosis was markedly less observed in KO mice, though the rate of proliferation of alveolar epithelial cells was similar in KO and wild mice. The initial detachment of alveolar epithelial cells from basement membrane and the migration may be blocked in KO mice. Intraalveolar fibrosis in KO mice was mainly mural incorporation and obliteration types, but bud type was less prominent than wild mice, because of retarded alveolar epithelial cell coverage on intraalveolar fibrosis. Alveolar bronchiolization in MMP-2 KO mice was formed similarly to wild mice, although it is reported that the bronchiolization was blocked in MMP-9 KO mice.

间质性肺炎中的纤维化通常在肺泡内形成，并被再生的肺泡或支气管上皮细胞覆盖。除此之外，激活的 MMP-2 对间质性肺炎的肺泡修复过程和胎儿肺的肺泡形成也很重要。在这种情况下，我们研究了 MMP-2 KO 和野生小鼠的博莱霉素肺。对小鼠气管内给予博莱霉素后，依次处死动物。对 MMP-2、角蛋白、PCNA、纤连蛋白进行了电子显微镜研究和免疫组织化学研究。通过Ashcroft法和肺组织中羟脯氨酸的量对纤维化程度进行定量。通过蛋白质印迹和明胶酶谱分析肺匀浆中 MMP-2 的活性形式。在 KO 小鼠和野生小鼠中也观察到类似的纤维化程度。尽管 KO 小鼠和野生小鼠的肺泡上皮细胞增殖率相似，但 KO 小鼠中观察到的 II 型肺泡上皮细胞对肺泡内纤维化的覆盖明显较少。在 KO 小鼠中，肺泡上皮细胞与基底膜的最初脱离和迁移可能被阻止。 KO小鼠的肺泡内纤维化主要是壁合并型和闭塞型，但芽型较野生小鼠不那么突出，因为肺泡上皮细胞对肺泡内纤维化的覆盖延迟。 MMP-2 KO 小鼠中肺泡细支气管化的形成与野生小鼠类似，但据报道，MMP-9 KO 小鼠中细支气管化被阻断。