环氧合酶2抑制剂对高氧环境下新生大鼠肺组织肺表面活性物质相关蛋白B、转化生长因子-β1表达的影响

Influence of cyclooxygenase -2 inhibitor on the expressions of surfactant protein B and transforming growth factor β1 of newborn rats in hyperoxia environment

目的探讨环氧合酶-2抑制剂对高体积分数氧（高氧）环境下新生大鼠肺组织肺表面活性物质相关蛋白B（SP-B）、转化生长因子-β1（TGF-β1）表达的影响。方法将新生SD大鼠105只按随机数字表法分为3组（每组35只）：空气组（I组）大鼠置于空气中；高氧组（Ⅱ组）置于850mL／L氧气中；塞来昔布干预组（Ⅲ组）置于850mL／L氧气，每天腹腔注射塞来昔布5mg／kg。于出生3、7、14d处死大鼠，右下肺组织HE染色，光镜下观察其病理学改变；左肺进行肺灌洗，酶联免疫吸附试验（ELISA）检测支气管肺泡灌洗液SP-B、TGF-β1水平；右上肺组织一部分进行免疫组织化学检测，光镜观察肺组织SP-B、TGF-β1表达，一部分进行实时荧光定量聚合酶链反应（RT-PCR）检测SP-B、TGF-β1 mRNA表达。结果Ⅰ组大鼠肺泡结构正常，无炎性细胞浸润；Ⅱ组大鼠肺组织结构紊乱，肺泡内有出血、液体渗出；Ⅲ组大鼠肺组织形态及结构改变均较Ⅱ组明显减轻。ELISA法检测SP-B表达：14d时Ⅰ组为（29．93±6．40）ng／L，Ⅱ组为（18．20±3．70）ng／L，Ⅲ组为（19．63±10．20）ng／L；Ⅱ组表达较Ⅰ组明显减少，差异有统计学意义（t=13．152，P〈0．01）；Ⅲ组表达较Ⅱ组明显增多，差异有统计学意义（t=5．190，P〈0．01）。TGF-β1表达：14d时Ⅰ组为（34．73±2．30）ug／L，Ⅱ组为（41．66±1．80）ug／L，Ⅲ组为（38．03±0．20）ug／L；Ⅱ组表达较Ⅰ组明显增多，差异有统计学意义（t=6．584，P〈0．01）；Ⅲ组表达较Ⅱ组明显减少，差异有统计学意义（t=5．609，P〈0．01）。肺组织RT-PCR检测mRNA表达：SP-BmRNA表达，14d时I组为3．144-0．10，Ⅱ组为0．81±0．06，11组为1．12±0．06；Ⅱ组表达较Ⅰ组明显减少，差异有统计学意义（t=55．050，P〈0．01）；Ⅲ组表达较Ⅱ组明显增多，差异有统计学意义（t=10．305，P〈0．01）。TGF-β1 mRNA表达：14d时Ⅰ组为1．94±0．03，Ⅱ组为13．26±0．43，Ⅱ组为6．49±0．26；Ⅱ组表达较Ⅰ组明显增多，差异有统计学意义（t=75．471，P〈0．01）；Ⅲ组表达较Ⅱ组明显减少，差异有统计学意义（t=38．470，P〈0．01）。结论环氧合酶-2抑制剂可能通过抑制前列腺素减轻炎性反应，从而缓解高氧下新生大鼠的肺损伤。

Objective To investigate the effects of selective cyclooxygease - 2 inhibitor on pulmonary surfactant protein（SP -B） and transforming growth factor（ TGF - β1 ） of hyperoxic lung injury in newborn rats. Methods One hundred and five SD rats were randomly divided into 3 groups （35 cases in each group） ：air group（ group Ⅰ） ,in which the rats were exposed to room air; hyperoxia group（ group Ⅱ）, in which the rats were exposed to hyperoxia （850 mL/L oxygen） ;Celecoxib group（ group Ⅲ） ,in which the rats were exposed to heyperoxia（850 mL/L oxygen） and intraperitoneally injected with 5 mg/kg Celecoxib. The lungs of rats were removed on 3 d,7 d,14 d after birth and the following indices were measured：lung section from the lower fight lung were stained with HE, and the histological changes was examined; the contents of SP - B and TGF - β1 in the bronehoalveolar lavage fluid of left lung was determinated by using enzyme - linked immunosorbent assay（ELISA）;fight upper lung was immunohistochemically stained to measure the contents of SP- B and TGF- β1 ,quantitative real- time PCR（ RT- PCR） was used to detect the mRNA expression of SP- B and TGF - β1. Results There were no inflammatory cells and exudation in the lung in group Ⅰ ;in group Ⅱ, the structure disorder, pulmonary edema, and inflammatory infiltrates were found;but the damage was obviously alleviated in group Ⅲ. Protein expression could be better detected by ELISA, at the time of 14 day, SP - B was expressed at different levels in3 groups：（29.93 ±6.40） ng/L in group Ⅰ ,（18.20±3.70） ng/L in group Ⅱ and （19.63 ±10.20） ng/L in group Ⅲ, SP - B level in group Ⅱ was significantly lower than that in group Ⅰ （ t = 13. 152, P 〈 0.01 ）, and the expression in group Ⅲ was significantly higher than that in group Ⅱ （t =5. 190,P 〈0.01 ）. TGF - β1 was expressed at different levels in3 groups：（34.73 ±2.30） μg/L in group Ⅰ ,（41.66 ±1.80） u/L in group Ⅱ and （38.03 ±0.20） μg/L in group Ⅲ ,and the level of TGF - β1 was significantly higher in group Ⅱ than that in group Ⅰ （t =6. 584,P 〈 0.01 ） ,but the expression of group m was significantly lower than that in group Ⅱ （t =5. 609,P 〈0.01 ）. The expression of mRNA was detected by RT - PCR, and at the time of 14 day, SP - B mRNA was expressed at different levels in 3 groups：3.14±0. 10 in group Ⅰ ,0.81 ±0.06 in group Ⅱ and 1.12 ±0.06 in group Ⅲ ,and SP -B level in group Ⅱ was significantly lower than that in the group Ⅰ （ t = 55. 050, P 〈 0.01 ） , and the expression in group Ⅲ was significantly higher than that in group Ⅱ （ t = 10. 305, P 〈 0.01 ）. TGF - β1 mRNA was expressed at different levels in the 3 groups ： 1.94 ± 0.03 in group Ⅰ , 13.26 ± 0.43 in group Ⅱ and 6.49 ± 0.26 in group Ⅲ, the level of TGF - β1 was significantly higher in group H than that in group Ⅰ （ t = 75. 471, P 〈 0.01 ）, while the expression of group IU was significantly lower than that in group Ⅱ （ t = 38.470, P 〈 0. 01 ）. Conclusions Cyclooxygenase - 2 inhibitor can attenuate hypemxic lung injury in rats,and the mechanism might be related to the reduction of prostaglandin.