CAJ | 학술논문

目的探讨维甲酸(RA)对高氧肺损伤保护作用机制及其与调控丝裂原活化蛋白激酶(MAPKs)关系.方法建立高氧(85%)暴露早产SD大鼠肺损伤模型,运用RT-PCR方法检测基质金属蛋白酶2,9(MMP-2、-9)mRNA表达,采用明胶酶谱法检测MMP-2和MMP-9酶原及活酶表达,采用Western blot技术检测磷酸化和非磷酸化总的ERK1/2、JNK1/2和038蛋白质表达.结果与空气组比较,高氧暴露4、7、14 d,MMP-2和MMP-9 mRNA的表达均显著提高(P均<0.01),MMP-2活酶(除4 d外)、MMP-9酶原及活酶的表达明显上调(P<0.05或P<0.01),磷酸化ERK1/2、JNK1/2和p38表达显著增加(P均<0.01);与高氧组比较,4、7、14 d时,RA明显下调高氧暴露后MMP-2(除14d外)、MMP.9 mRNA的表达(P<0.01或P<0.05),不同程度降低MMP-2活酶、MMP.9酶原及活酶的表达和显著下调磷酸化JNK1/2、038水平,进一步上调磷酸化ERK1/2表达.结论高氧暴露显著提高MMP-2和MMP-9表达,是造成肺损伤的重要因素;JNK1/2和p38信号途径可能参与了高氧暴露下早产大鼠肺组织MMP-2和MMP-9的表达调控;RA可通过降低JNK1/2和p38磷酸化水平,抑制MMP-2和MMP-9的高表达和活化,从而发挥高氧肺损伤保护作用.
목적 탐토유갑산(RA)대고양폐손상보호작용궤제급기여조공사렬원활화단백격매(MAPKs)관계.방법 건립고양(85%)폭로조산SD대서폐손상모형,운용RT-PCR방법검측기질금속단백매2,9(MMP-2、-9)mRNA표체,채용명효매보법검측MMP-2화MMP-9매원급활매표체,채용Western blot기술검측린산화화비린산화총적ERK1/2、JNK1/2화038단백질표체.결과 여공기조비교,고양폭로4、7、14 d,MMP-2화MMP-9 mRNA적표체균현저제고(P균<0.01),MMP-2활매(제4 d외)、MMP-9매원급활매적표체명현상조(P<0.05혹P<0.01),린산화ERK1/2、JNK1/2화p38표체현저증가(P균<0.01);여고양조비교,4、7、14 d시,RA명현하조고양폭로후MMP-2(제14d외)、MMP.9 mRNA적표체(P<0.01혹P<0.05),불동정도강저MMP-2활매、MMP.9매원급활매적표체화현저하조린산화JNK1/2、038수평,진일보상조린산화ERK1/2표체.결론 고양폭로현저제고MMP-2화MMP-9표체,시조성폐손상적중요인소;JNK1/2화p38신호도경가능삼여료고양폭로하조산대서폐조직MMP-2화MMP-9적표체조공;RA가통과강저JNK1/2화p38린산화수평,억제MMP-2화MMP-9적고표체화활화,종이발휘고양폐손상보호작용.
Objective To further investigate the protective effect of retinoic acid (RA) on hyperoxia ieduced lung iniury and the role of RA as a modulator on mitogen-activated protein kinases (MAPKs).Methods Establishment of hypemxia(85%)induced lung injury model of premature SpragueDawley (SD) rats:21 d gestational age SD rat's fetuses (term=22 d)were delivered by hysterectomy.Within 12-24 h after birth,the premature rat pups were randomly divided into 4 groups:Group I,airexposed control group;Group Ⅱ,hyperoxia-exposed group;Group Ⅲ,air plus RA-exposed group,Group Ⅳ,hypemxia plus RA-exposed group.Group Ⅰ and Ⅲ were remained in room air,and group Ⅱ and Ⅳ were placed in 85% oxygen.The pups in Group Ⅲ and Ⅳ were injected with RA (500 μg/kg,every day)intraperitoneally.The entire lung tissues of premature rat pups were collected at 4 d,7 d and 14 d.The mBNA levels of MMP-2 and MMP-9 were detected by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR).MMP-2 and MMP-9 activities were measured by zymography.Western blot was used to detect phosphorylated and total nonphosphorylated form of ERKs,JNKs and p38.Results Exposure to oxygen for 4 d,7 d,and 14 d resulted in mcreased mRNA levels of MMP-2 and MMP-9 compared with air-exposed control group(P<0.01 for all).The mean protein levels of active MMP-2 and pro/active MMP-9 after exposure to O2 were higher than air control groups on each experimental day(P<0.01 or<0.05).The phosphorylated ERKl/2,JNKl/2 and p38 proteins in hyperoxia-exposed group increased markedly compared with air-exposed control group(P<0.01 fur all).The pups treated with RA in the hypemxic environment expressed significantly lower mRNA levels of MMP-2 and MMP-9 than the hyperoxic control pups on each experimental day(P<0.05 for all).The leveh of active MMP-2 and pro/active MMP9 decreased to a different degree after BA treatment in hyperexia exposure rat pups.In addition,RA treatment led to a decrease of p-JNK1/2 and p-38(P<0.01 for all)protein levels and a further elevation of P-ERK1/2 compared with hyperoxia-exposed group. Condusion Hypemxia exposure elevated the expression of MMP-2 and MMP-9 markedly,which played a role in oxygen-induced lung injury.RA could have a protective effect on hyperoxia induced lung injury by decreasing active levels of JNK and p38,which subsequently reduce the expression and activation of MMP-2 and MMP-9.