水通道蛋白4基因敲除对博莱霉素诱导小鼠肺纤维化的影响

目的：评价水通道蛋白4（AQP4）在博莱霉素诱导的小鼠肺纤维化中的作用。方法：采用博莱霉素3 mg/kg气管内注射诱导AQP4基因敲除（AQP4-/-）小鼠发生肺纤维化，以野生型小鼠为对照，造模后第3、7、14、28天处死动物，检测肺系数、血清转化生长因子 β1（TGF β1）、肿瘤坏死因子 α（TNF α）水平和肺组织羟脯氨酸含量，作肺组织病理切片行HE染色和Masson染色观察肺部炎症及纤维化程度。结果：造模第14天，野生型小鼠肺系数增高为野生型对照小鼠的19倍（1269 ± 605与680 ± 082，q=4204，P<005）；AQP4-/-小鼠肺系数增高为AQP4-/-对照小鼠的23倍（1405 ± 582与605± 058，q=5172，P<001），但与野生型小鼠比较，AQP4基因敲除对博莱霉素诱导的小鼠肺纤维化过程中肺系数增高无明显影响（P>005）。小鼠肺组织羟脯氨酸含量随造模时间逐步增加，造模第28天，野生型小鼠肺组织羟脯氨酸含量增加为对照的155倍［（085 ± 022）μg/mg与（055 ± 014）μg/mg，q=4313，P<005］；AQP4-/-小鼠肺组织羟脯氨酸含量增加为对照的14倍［（084 ± 013）μg/mg与（060 ± 014）μg/mg，q=4595，P<005］，但与野生型小鼠比较，AQP4基因敲除对小鼠肺纤维化过程中肺组织羟脯氨酸含量增加无明显影响（P>005）。造模后，小鼠血清TGF β1、TNF α水平有增加趋势，但这两个指标在野生型和AQP4-/-小鼠间差别无统计学意义（均P>005）。肺组织病理学检查结果表明AQP4基因敲除对博莱霉素诱导的小鼠肺部炎症和纤维化无明显影响。结论：AQP4基因敲除对博莱霉素诱导的小鼠肺纤维化未产生明显影响。

Effects of the water channel aquaporin 4 deficiency on bleomycin induced lung fibrosis in mice

Objective： To evaluate the effect of water channel aquaporin 4 （AQP4） on bleomycin induced lung fibrosis in mice. Methods： In wild type and AQP4 gene knockout （AQP4-/-） mice， lung fibrosis was induced by injection of bleomycin （3 mg/kg） into the trachea and saline injection was used as a control. At d3， 7， 14， 28 after bleomycin treatment， mice were randomly sacrificed in batch and the lung coefficient was determined. Serum levels of TGF β1 and TNF α were measured by ELISA and hydroxyproline contents in lung tissue were determined by Alkaline hydrolysis method. H E staining and Massons staining were performed to examine the pathological changes of lung tissues after bleomycin treatment. Results： On d14 after bleomycin treatment， the lung coefficients in wild type mice and AQP4-/- mice were 19 fold （1269 ± 605 vs 680 ± 082，q=4204，P<005） and 23 fold （1405 ± 582 vs 605± 058， q=5172，P<001） of that in control， respectively， but no significant difference was found between wild type and AQP4-/- mice in the lung coefficient value （P>005）. The hydroxyproline contents in the lung increased after bleomycin treatment; on d28， the lung hydroxyproline contents in wild type and in AQP4-/- mice were 155 fold （085 ± 022 g/mg vs 055 ± 014 μg/mg， q=4313，P<005） and 14 fold （084 ± 013 μg/mg vs 060 ± 014μg/mg， q=4595，P<005） of that in control， respectively， but no significant difference was noticed between wild type and AQP4-/- mice in lung hydroxyproline contents. There was a tendency that serum TGF β1 and TNF α levels increased in bleomycin treated mice， but no significant difference was found between wild type and AQP4-/- mice. AQP4 knockout showed no effects on pathological changes of lung tissues with H E staining and Massons staining in mice with bleomycin induced lung fibrosis. Conclusion： AQP4 might not be involved in bleomycin induced lung fibrosis in mice.