姜黄素预先给药对单肺通气诱发小鼠急性肺损伤时JNK信号通路的影响

Effect of curcumin pretreatment on JNK signaling pathway during one-lung ventilation-induced acute lung injury in mice

目的评价姜黄素预先给药对单肺通气诱发小鼠急性肺损伤时c—Jun氨基末端激酶（JNK）信号通路的影响。方法SPF级雄性C57BL／6J小鼠90只，6—9周龄，体重18～24g，采用随机数字表法，将其分为6组（n=15）：双肺通气组（TLV组）、单肺通气组（OLV组）、姜黄素100、150、200及250mg／kg组（C100组、C150组、C200组和C250组），C100组、C150组、C200组和C250组于单肺通气前2h时腹腔注射相应剂量姜黄素。气管插管后行容量控制通气，调整通气参数，维持P ET CO2 35～45mmHg，OLV组、C100组、C150组、C200组和C250组行右侧单肺通气1．5h时再行双肺通气O．5h，TLV组行双肺通气2．0h。机械通气结束后取左肺，分别在光镜和电镜下观察肺组织病理学结果，记录肺泡损伤的定量评价指标（IQA），确定肺组织湿重／干重比（W／D）比值，采用TUNEL法检测肺组织细胞凋亡情况，计算细胞凋亡指数（AI），采用RT—PCR法和Western blot法分别检测JNK mRNA、JNK和磷酸化JNK表达，计算JNK磷酸化水平。结果与TLV组比较，OLV组肺组织IQA、W／D比值、AI、JNK mRNA表达及JNK磷酸化水平升高（P〈0．05）；与OLV组比较，C150组、C200组和C250组肺组织IQA、W／D比值、AI、JNK mRNA表达及JNK磷酸化水平降低，C100组、C150组、C200组和C250组上述指标依次降低（P〈0．05），C100组上述指标比较差异均无统计学意义（P〉0．05）。与OLV组比较，C150组、C200组和C250组肺组织病理学损伤减轻，且依次减轻。结论姜黄素预先给药减轻单肺通气诱发小鼠急性肺损伤时细胞凋亡的机制与抑制JNK信号通路激活有关。

Objective To evaluate the effect of curcumin pretreatment on c-Jun N-terminal kinase （JNK） signaling pathway during one-lung ventilation （OLV）-induced acute lung injury in mice. Methods Ninety SPF male C57BL/6J mice, aged 6-9 weeks, weighing 18-24 g, were randomly divided into 6 groups （n= 15 each） using a random number table： two-lung ventilation （TLV） group; OLV group; curcumin 100, 150, 200 and 250 mg/kg groups （C100, C150, C200 and C250 groups）. The corresponding doses of curcumin were administered intraperitoneally at 2 h before one-lung ventilation in C100 , C150 , C200 and C250 groups. The animals were tracheally intubated and mechanically ventilated in volume-controlled mode. The ventilator settings were adjusted to maintain the end-tidal pressure of carbon dioxide at 35-45 mmHg. In OLV, C100, C150 , C200 and C250 groups, unilateral lung was ventilated for 1.5 h followed by 0.5 h of TLV. Bilateral lungs were ventilated for 2.0 h in group TLV. Peak airway pressure and airway pressure were recorded at 1.5 h of OLV and 0.5 h of TLV. At the end of mechanical ventilation, left lungs were removed for microscopic examination of the pathologic changes, and the index of quantitative assessment for alveolar damage （IQA） was recorded. Wet/dry lung weight ratio （W/D ratio） was determined, and the cell apoptosis in lung tissues was detected using TUNEL. The apoptosis index （AI） was calculated. The expression of JNK mRNA was determined using real-time polymerase chain reaction. The expression of JNK and phosphorylated JNK was determined by Western blot. The phosphorylation of JNK was calculated. Results Compared with group TLV, the IQA, W/D ratio, AI, expression of JNK mRNA and phosphorylation of JNK were significantly increased in group OLV （P〈 0.05 ）. Compared with group OLV, the IQA, W/D ratio, AI, expression of JNK mRNA and phosphorylation of JNK were significantly decreased in C150 , C200 and C250 groups, the parameters mentioned above were significantly decreased in sequence in C100, C150, C200 and C250 groups （P〈 0.05）, and no significant change was found in the parameters mentioned above in group C 100 （P〉 0.05）. Compared with group OLV, the pathological changes were significantly attenuated in sequence in C150, C200 and C250 groups. Conclusion The mechanism by which curcumin pretreatment reduces cell apoptosis during OLV-induced acute lung injury is related to inhibition of JNK signaling pathway activation in mice.