线粒体融合蛋白2在姜黄素减轻脓毒症小鼠淋巴细胞凋亡中的作用

Curcumin inhibits lymphocyte apoptosis in septic mice and its relation with mitofusin 2

目的研究线粒体融合蛋白2(Mfn2)在姜黄素减轻脓毒症小鼠淋巴细胞凋亡中的作用。方法将清洁级雄性Balb/c小鼠165只随机分为假手术组、脓毒症组、姜黄素干预组、姜黄素对照组、阴性病毒脓毒症组、阴性病毒姜黄素干预组、Mfn2干扰脓毒症组、Mfn2干扰姜黄素干预组,每组15只;剩余小鼠随机分为正常组、阴性病毒组、Mfn2干扰组,用于检测病毒转染效率,每组15只。脓毒症组及姜黄素干预组通过盲肠结扎穿孔术建立脓毒症小鼠模型,姜黄素干预组及姜黄素对照组予姜黄素200mg/(kg·d)灌胃1周,干扰组通过尾静脉注射携带相应干扰序列腺相关病毒建立模型,各组均于24h后处死小鼠,无菌留取脾脏,提取淋巴细胞。流式细胞术检测淋巴细胞凋亡情况以及线粒体膜电位,Western blot检测淋巴细胞Mfn2、Caspase-3、Bcl-2、Bax表达水平。结果与假手术相比,脓毒症组小鼠淋巴细胞Mfn2表达、Bcl-2/Bax明显降低(均P<0.05),脓毒症组小鼠淋巴细胞凋亡率、Caspase-3表达、线粒体膜电位降低率明显升高(均P<0.05)。姜黄素预处理后,与脓毒症组相比,Mfn2、Bcl-2/Bax表达均明显升高(均P<0.05),淋巴细胞凋亡率、Caspase-3表达、线粒体膜电位降低率均明显降低(均P<0.05)。下调Mfn2后,与脓毒症组相比,姜黄素干预组凋亡率及Caspase-3、Bcl-2/Bax表达水平均无统计学差异(均P>0.05)。结论姜黄素抑制脓毒症小鼠的淋巴细胞凋亡,其作用依赖于Mfn2的表达。

Objective To investigate the effect of curcumin on sepsis-induced lymphocyte apoptosis in mice and its relation with mitofusin(Mfn2).Methods One hundred and sixty-five male Balb/c mice were randomized into sham operation group,sepsis group,curcumin intervention group,curcumin control group,negative virus-sepsis group,negative virus-curcumin intervention group,Mfn2 interference-sepsis group,Mfn2 interference-curcumin intervention group with 15 rats in each group;the remaining mice were randomly divided into normal group,negative virus group,Mfn2 interference group for detection of virus transfection efficiency with 15 rats in each group.The septic was induced by cecal ligation and puncture(CLP).The curcumin intervention group and the curcumin control group were given 200mg/(kg·d)curcumin dissolved in corn oil for one week by intragastric administration.The adeno-associated virus with the corresponding interference sequence was established by tail vein injection.The mice were sacrificed after 24h of treatment,and then the spleen was removed to extract lymphocytes.Apoptosis and mitochondrial membrane potential were detected by flow cytometry.Mfn2,Caspase-3,Bcl-2 and Bax levels were detected by Western blot.Results Compared with sham group,the expression of Mfn2 significantly decreased in sepsis group(P<0.05).The levels of Bcl-2/Bax also significantly reduced(P<0.05),whereas the apoptosis rate of spleen lymphocytes in sepsis group significantly higher than that in sham group(P<0.05),and the expression of Caspase-3 significantly increased(P<0.05).Meanwhile,the reduction rate of mitochondrial membrane potentials in sham group was significantly increased by curcumin(P<0.05).The apoptosis rate and the levels of Caspase-3 significantly decreased compared with sepsis group(P<0.05).The levels of Mfn2 and Bcl-2/Bax were significantly up-regulated after pretreatment with curcumin(P<0.05).After down-regulation of Mfn2,there were no significant difference in apoptosis rate,Caspase-3 and Bcl-2/Bax between the curcumin group and the sepsis group.Conclusion Curcumin inhibits lymphocyte apoptosis in septic mice,and its effect depends on the expression of Mfn2.