MMP-9和TIMP-1在高氧致CLD新生大鼠肺组织的动态变化及其对Ⅳ型胶原的影响(英文)

Dynamic expression and effects of MMP-9 and TIMP-1 on type Ⅳ collagen in lung tissue of neonatal rats with hyperoxia-induced CLD

目的探讨MMP-9(基质金属蛋白酶-9)和TIMP-1(基质金属蛋白酶抑制物-1)在高氧致CLD新生大鼠肺组织中的动态变化和在Ⅳ型胶原重塑中的作用。方法足月新生大鼠在生后12h内分别持续吸入浓度为0.90～0.95的高氧和空气,于1,3,7,14和21d,应用免疫组化的方法分别检测肺组织MMP-9和TIMP-1蛋白表达的动态变化,同时采用ELISA法动态检测肺组织中Ⅳ型胶原蛋白含量。结果MMP-9在高氧3d时的表达较空气组增强,蛋白平均灰度值为:(126.23±6.95)vs(130.38±7.36),P<0.05,其余时间点两组比较差异无显著性;TIMP-1在3d后高氧组肺组织的表达均高于空气组,3d和7d时平均灰度值为:(126.22±6.49)vs(129.49±4.75),(119.70±7.33)vs(124.99±6.83)(P<0.05),14d和21d差异有显著性,值为(112.35±10.29)vs(120.08±7.77),(109.19±10.56)vs(118.22±6.32)(P<0.01);高氧组ColⅣ含量在14d[(24.78±5.42)vs(14.90±2.44),P<0.05]和21d[(40.27±1.94)vs(26.13±1.94),P<0.01]均高于空气组。结论新生大鼠随着吸入高氧时间的延长,MMP-9/TIMP-1的平衡状态遭到破坏,Ⅳ型胶原降解失衡,促进了早期基膜损伤的加重和晚期伴有Ⅳ型胶原沉积的肺纤维化。

[Objective] To investigate the dynamic changes of matrix metalloproteinase-9 （MMP-9） and tissue inhibitors of metalloproteinase-1 （TIMP-1） in lung of neonatal rats after inhaling high concentration of oxygen （hyperoxia）, and the effects on type Iveollagen remodeling. [Methods] Full-term newborn rats were continuously exposed to oxygen （0.90～0.95） or room air （0.21O2） within 12 hours after birth. On day 1, 3, 7, 14 and 21, the contents of type Iv eollagen in lungs were detected by enzyme linked immunosorbent assay （ELISA）, the changes of MMP-9 and TIMP-1 expression were measured by immunohistoehemistry. [Results] The protein content of type Iveollagen in hyperoxia group increased significantly on the 14th day [（24.78±5.42） vs （14.90±2.44）, P 〈0.05] and the 21st day [（40.27±1.94） vs （26.13±1.94）, P 〈0.01] compared to that in control group, the expression of MMP-9 increased on the 3rd day in hyperoxia groups, the average values of protein were （126.23±6.95） vs （130.38±7.36） （P 〈0.05）, while no difference was seen on other days, higher values of TIMP-1 protein expression were seen on the 3rd day [（126.22±6.49） vs （129.49±4.75）] and the 7th day [（119.70＋7.33） vs （124.99＋6.83）] （P〈0.05）, which increased significantly compared with the control group on the 14th day [（112.35±10.29） vs （120.08±7.77）] and the 21st day [（109.19±10.56） vs （118.22±6.32）] （P 〈0.01）. [Conclusion] With prolonged hyperoxia, the balance of MMP-9/ TIMP-1 can not been kept, type Iveollagen breakdown is not balanced, which maybe make the basement membrane damage in early stage and lead to type Iveollagen deposition and lung fibrosis in late stage.