吡咯烷二硫代氨基甲酸对脂多糖诱导小鼠急性呼吸窘迫综合征肺组织凋亡因子表达影响的研究

Effects of PDTC on Apoptosis Factor Expression of LPS-induced Mouse ARDS Lung Tissue

目的探讨吡咯烷二硫代氨基甲酸(PDTC)对脂多糖(LPS)诱导小鼠急性呼吸窘迫综合征(ARDS)肺组织细胞凋亡的机制。方法实验小鼠随机分为对照组、模型组和干预组。采用腹腔内注射LPS20mg/kg复制小鼠ARDS动物模型,干预组在注射LPS前30min腹腔内注射PDTC120mg/kg,分别在注射LPS后4、8、12h三个时相收集标本;对照组腹腔内注射NS20mL/kg进行比较。RT-PCR法检测各组肺组织中Bcl-2、Bax及caspase-3的表达水平;荧光酶标分析法检测各组肺组织中caspase-3蛋白酶水平。结果①一般状况:对照组小鼠呼吸平顺、饮食正常、活动自如;模型组小鼠腹腔注射LPS后,呼吸急促,饮食量下降,活动减少;干预组小鼠相对模型组其呼吸较畅顺,饮食量及活动能力下降不明显。模型组及干预组随着实验时间的延长其症状呈加重趋势。②各组肺组织Bcl-2、Bax及caspase-3的表达水平:模型组及干预组肺组织Bcl-2表达水平均较对照组明显增加,干预组增加程度较模型组多,模型组及干预组随实验时间推移呈上升趋势(P<0.05)。模型组肺组织Bax、caspase-3表达水平较对照组明显升高,干预组介于对照组与模型组之间,模型组及干预组随实验时间延长呈上升趋势(P<0.05)。③各组肺组织caspase-3蛋白酶水平:模型组肺组织caspase-3蛋白酶水平较对照组含量增加明显,干预组介于对照组与模型组之间,模型组及干预组蛋白酶水平随实验时间延长呈减少趋势(P<0.05)。结论PDTC预处理能减轻LPS诱导小鼠ARDS肺组织损伤,其机制与上调抑凋亡因子Bcl-2、下调促凋亡因子Bax及caspase-3等密切相关。

Objective To investigate the mechanism of lung tissue apoptosis in LPS-induced mice ARDS via PDTC pretreatment.Methods The experimental mice were randomly divided into control group,model group and intervention group.LPS 20 mg/kg was intraperitoneally injected to duplicate mouse animal models with ARDS.30 min before injection of LPS,PDTC of 120 mg/kg was intraperitoneally injected in intervention group,and samples were collected 4 h,8 h and 12 h after injection of LPS.Normal saline(NS)of 20 mL/kg was intraperitoneally injected in control group.Real-time polymerase reaction(RT-PCR)was used to detect the levels of Bcl-2,Bax and caspase-3 in lung tissues in each group.Fluorescence enzyme immunosorbent assay was applied to detect the level of caspase-3 protease in lung tissues in each group.Results①Generally,the mice in the control group showed smooth respiration,normal diet and free activity,while those in the model group exhibited polypnea,reduced amount of diet and decrease of activity after injection of LPS,and those in the intervention group had relatively smooth respiration,and insignificant decrease of diet amount and activity.The symptoms were in a deteriorating tendency along with study time in the model group and intervention group.②The expression levels of Bcl-2,Bax and caspase-3 in lung tissues in each group:Bcl-2 expression in the lung tissues increased prominently in the lung tissues in the model group and intervention group than that in the control group,which increased more significantly in the intervention group than that in the model group.Bcl-2 expression was in an increasing tendency along with time in the model group and intervention group,and there was significant difference(P<0.05).Bax and caspase-3 expressions in the lung tissues increased evidently in the model group than that in the control group,and the increase in the intervention group was between the control group and model group.Bax and caspase-3 expressions were in an increasing tendency along with time in the model group and intervention group,and there were significant differences(P<0.05).③Caspase-3 protease level in the lung tissues in each group:caspase-3 protease level in the lung tissues increased notably in the model group than that in the control group,and the level in the intervention group was between the control group and model group.However,caspase-3 protease level was in a decreasing tendency along with time in the model group and intervention group,and there was significant difference(P<0.05).Conclusion PDTC pretreatment could attenuate the lung injury induced by LPS in ARDS mice,and the underlying mechanism is closely related not only to up-regulation of apoptosis inhibitory factor Bcl-2,but also to down-regulation of the pro-apoptotic factors Bax and Caspase-3.