MAPKs信号阻断剂U0126对油酸致急性肺损伤大鼠肺泡Ⅱ型上皮细胞中AQP4表达的影响

目的 观察大鼠肺泡Ⅱ型上皮细胞(AT-Ⅱ)上AQP4与MAPKs信号转导通路在早期急性呼吸窘迫综合征时的相互联系.方法 实验分正常组、油酸肺损伤组及加药组.加药组给予U0126,余两组予二甲基亚砜作为对照.测动脉血气、血管外肺水(EVLW),观察肺组织病理改变评价早期肺损伤程度.急性分离纯化大鼠AT-Ⅱ,行鞣酸染色、碱性磷酸酶染色(AKP)鉴定.采用逆转录-聚合酶链反应(RT-PCR)法检测肺泡Ⅱ型上皮细胞中AQP-4的mRNA的表达量.结果 血气分析、肺组织HE染色、EVLW 显示损伤组明显高于正常组,加药组较损伤组无明显变化.AQP4 mRNA表达损伤组最高,加药组较损伤组明显减少.结论 大鼠肺泡Ⅱ型细胞上AQP4 mRNA在不同组的表达变化,表明急性肺损伤时启动了MAPKs信号传导通路且增加AOP4 mRNA的表达.

Abstract：

Objective To investigate the relationship between aquaporin 4 (AQP4) in alveolar type II (AT-Ⅱ) cells and MAPK signaling pathway in rats with early-stage oleic acid-induced acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). Methods Three groups of rats, namely the normal control, ALI and U0126 treatment group were used in this study.After oleic acid-induced ALI in the latter two groups, the rats in the treatment group received 100 μ,mol/L U0126 treatment at the dose of 10 μ1, and dimethyl sulfoxide (DMSO) were given in the normal control and ALI groups. Arterial blood gas and the extravascular lung water (EVLW) content were measured after the treatments, and pathological changes in the lung tissues were observed microscopically. ATII cells were isolated from the lung tissues and identified using tannic acid staining and alkaline phosphatase (APK) staining. The expression of AQP-4 mRNA in the cells was detected with RT-PCR. Results Blood gas analysis, HE staining and EVLW content measurement revealed severer injury of the lung tissues in ALI group than in the normal control group, but the severity was comparable between the treatment and ALI groups. RT-PCR demonstrated significantly increased AQP-4 mRNA expression in ALI group as compared with that in the normal control group, and U0126treatment resulted in obvious reduction in AQP-4 mRNA expression in the U0126 treatment group. Conclusions Oleic acid-induced ALI results in the activation of MAPK signaling pathway and up-regulation of AQP-4 mRNA expression in the ATII cells of rats.

Effect of MAPK signal transduction pathway inhibitor U0126 on aquaporin 4 expression in alveolar type II cells in rats with oleic acid-induced acute lung injury

Objective To investigate the relationship between aquaporin 4 (AQP4) in alveolar type II (AT-Ⅱ) cells and MAPK signaling pathway in rats with early-stage oleic acid-induced acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). Methods Three groups of rats, namely the normal control, ALI and U0126 treatment group were used in this study.After oleic acid-induced ALI in the latter two groups, the rats in the treatment group received 100 μ,mol/L U0126 treatment at the dose of 10 μ1, and dimethyl sulfoxide (DMSO) were given in the normal control and ALI groups. Arterial blood gas and the extravascular lung water (EVLW) content were measured after the treatments, and pathological changes in the lung tissues were observed microscopically. ATII cells were isolated from the lung tissues and identified using tannic acid staining and alkaline phosphatase (APK) staining. The expression of AQP-4 mRNA in the cells was detected with RT-PCR. Results Blood gas analysis, HE staining and EVLW content measurement revealed severer injury of the lung tissues in ALI group than in the normal control group, but the severity was comparable between the treatment and ALI groups. RT-PCR demonstrated significantly increased AQP-4 mRNA expression in ALI group as compared with that in the normal control group, and U0126treatment resulted in obvious reduction in AQP-4 mRNA expression in the U0126 treatment group. Conclusions Oleic acid-induced ALI results in the activation of MAPK signaling pathway and up-regulation of AQP-4 mRNA expression in the ATII cells of rats.