脂质前列腺素E1对急性肺损伤T细胞特异性转录因子T—bet与Gata-3的作用

Effects of Lipo-PGE1 on the expression of T-cell specific transcription factors T-bet/Gata-3 in acutelung injury

目的 探讨脂质体前列腺素E1（Lipo-PGE1）对脂多糖（lipopolysaccharide,LPS）诱导的小鼠急性肺损伤中表达失衡的转录因子T-bet/Gata-3的影响及其对Th1/Th2平衡的调节机制.方法 60只雌性BALB/C小鼠随机（随机数字法）分成3组（每组20只）：尾静脉注射生理盐水10 ml/kg为对照组,尾静脉注射LPS 5 mg/kg（稀释至0.5 mg/ml）为LPS模型组,给予LPS 1 h后给予脂质前列腺素E1 15 μg/kg尾静脉注射为治疗组（LPS＋ PGE1组）.各组于6h后观察肺组织变化,并测定肺湿/干质量比（W/D）.采用流式细胞仪分别检测Th1、Th2细胞的阳性率,SYBRGreen Ⅰ实时荧光定量PCR技术检测T-bet和Gata-3 mRNA的表达.应用SPSS 13.0统计软件行单因素方差分析.结果 模型组肺组织出现病理学改变,W/D为（5.74±0.31）较对照组（4.79±0.27）升高（P＜0.01）,而PGE1治疗组W/D（4.92±0.27）较模型组明显降低（P＜0.01）,肺组织病理学改变也明显减轻.模型组Th1、Th2细胞的阳性率及两者比值[（16.65±1.70）％,（9.40±1.25）％,（1.77 ±0.03）]较对照组[（23.67±2.10）％,（12.17±1.80）％,（1.95±0.04）]均显著降低,差异具有统计学意义（P＜0.01）；与模型组比较,PGE1治疗组上述3个指 标[（20.31±2.20）％,（10.50±0.80）％,（1.93 ±0.05）]均升高,差异具有统计学意义（P＜0.01）.模型组转录因子T-bet与Gata-3基因表达量及两者比值[（1.183 ±0.495）,（0.693±0.285）,（1.713 ±0.131）]较对照组[（3.439 ±0.557）,（1.203±0.238）,（2.857±0.290）]均降低,差异具有统计学意义（P＜0.01）；与模型组比较,PGE1治疗组T-bet基因的表达量（1.827 ±0.705）,T-bet与Gata-3表达量比值（2.502±0.352）均明显增高,差异有统计学意义（P＜0.01）,而Gata-3的表达量（0.719 ±0.186）增高不明显,差异无统计学意义（P＞0.05）.结论 脂质前列腺素E1可能通过增加T-bet基因的表达,纠正Th1/Th2平衡失调,从而改善相应的炎性症状.

Objective To investigate the effects of Lipo-PGE1 on the expression of T-bet and Gata-3,and its potential mechanisms causing the shift of T cells from Th1 to Th2 on Acute lung injury（ALI）induced by Lipopolysaccharide（LPS）in mice.Methods Sixty male BALB-C mice were randomly divided into three groups（n =20 in each group）：（1）control group,mice were treated with intravenous injection of NS in dose of 10 ml/kg,（2）LPS group,mice were exposed to LPS with dosage of 5 mg/kg（0.5 g/ml diluted in saline）,and（3）LPS ＋ PGE1 group,mice were treated with Lipo-PGE1 in dose of 15μg/kg.Sixhours after injection,the lungs were removed for observing the histopathological changes and determination of wet/dry lung weight（W/D）ratio.The levels of Th1 and Th2 were determined by flow cytometry,and the expressions of T-bet and Gata-3 mRNA were detected by using RT-PCR.One-way ANOVA was used for comparing differences between groups,and all data were presented in（（x）± s）.Results The histological changes of lung injury were lessened by PGEC ompared with the W/D ratio（5.74 ± 0.31）in LPS group,the one（4.92 ±0.27）in LPS ＋PGE1 group was lower significantly（P 〈0.01）.The levels of Th1 and Th2 and their ratio Were higher in LPS ＋PGE1 group[（20.31 ±2.20）%,（10.50±0.80）%,（1.93±0.05）]than in LPS group[（16.65 ±1.70）%,（9.40 ±1.25）%,（1.73 ±0.03）]（P〈0.01）.Compared with control group,the expressions ofT-bet mRNA（1.183 ±0.495）,and Gata-3 mRNA（0.693±0.285）,and their ratio（1.713 ± 0.131）were lower（P 〈0.01）; compared with LPS group,PGE1 significantly increased the expressions of T-bet mRNA（1.827 ± 0.705）and the ratio of T-bet/Gata-3 （2.502 ±0.352）（P 〈0.01）,while didn（t）increased the expressions of Gata-3 mRNA（0.7191 ±0.186）significantly（P 〉 0.05）.Conclusions Lipo-PGE1 may up-regulate transcription factor T-bet which participates in the Th1 differentiation ratio,and then improve the inflammatorv svmntom.