间质胶原酶在高氧所致急性肺损伤中的表达

Expression of collagenase in mice with hyperoxia-induced acute lung injury

目的研究间质胶原酶（interstitial collagenase）在高氧所致急性肺损伤发病过程中的作用，探讨急性肺损伤的发病机理。方法将72只C57BL／6小鼠随机分为正常对照组、高氧24h组、高氧48h组、高氧72h组，每组18只；正常对照小鼠呼吸室内空气，高氧小鼠置于密闭的氧气室（氧浓度〉95％）。评价肺损伤程度；逆转录一聚合酶链反应（RT-PCR）及免疫组织化学法测定肺组织间质胶原酶的表达及组织分布。统计分析采用单因素方差分析和q检验。结果高氧能引起急性肺损伤；RT-PCR结果显示肺组织间质胶原酶mRNA表达量在暴露于高氧24h后达（0．59±0．13）较对照组（0．07±0．01）明显增加（q≥3．15，P〈0．01），72h达最高（0．68±0．12，q=3．78，P〈0．01）；免疫组织化学研究显示问质胶原酶蛋白主要表达于气道上皮细胞、Ⅱ型肺泡上皮细胞和血管平滑肌细胞的胞浆中；问质胶原酶蛋白在气道上皮细胞的表达在高氧环境下24h达（28．54±9．60）较对照组（13．48±4．32）明显升高（q≥2．62，P〈0．05），于48、72h表达逐渐降低，分别为（20．32±5．68）和（15．24±4．65）。结论高氧能引起急性肺损伤伴间质胶原酶的表达增高，它们通过降解细胞外基质在高氧所致的急性肺损伤过程中发挥重要作用。

Objective To investigate the role of interstitial collagenase in the pathogenesis of acute lung injury induced by hyperoxia outside of sealed cages and breath room air, and to study the mechanism of The severity of lung injury. Methods Seventy-two C57BL/6 mice were divided into normal control group, hyperoxia for24 hours group, hyperoxia for 48 hours and hyperoxia for 72 hours group randomly, 18 mice in each group. The hyperoxia group exposed in sealed cages with 〉 95% oxygen, and the control group were put in the inspiratory room. The expression of interstitial collagenase mRNA and protein in lung tissues was studied by reverse transcript- polymerase chain reaction （RT-PCR） and immunohistochemistry. Results Hyperoxia caused acute lung injury in mice. by The expression of interstitial collagenase mRNA in lung tissues was increased after 24 hours of hyperoxia compared with their control group [ 0.59 ± 0.11 vs O. 07 ± 0.01, q = 3.15 P 〈 0.01 ], the expression was higher at 72 hours of hyperoxia （0.68 ± 0.12, q = 3.78 P 〈 0.01 ） . Immunohistochemistry study showed interstitial collagenase protein was mainly expressed in cytoplasm of airway epithelial cells, while Ⅱ type alveolar epithelial cells mainly and vascular smooth muscle cells in hyperoxia mice. The expression of interstitial collagenase protein in airway epithelium significantly increased at 24 hours of hyperoxia compared with their control group [ （28.54 ± 9.60） vs （13.48± 4.32） q = 2.62 P 〈 0.05], and the expression level was lower after 48 and 72 hours of hyperoxia （20.32 ± 5.68） vs, （ 15.24 ± 4.65）. Conclusion Hyperoxia cause acute lung injury in mice; interstitial collagenase play an important role in the development of hyperoxia-induced lung injury in mice.