摘要
为探讨产单核细胞李氏杆菌感染小鼠的肝细胞凋亡机制及不同毒力菌株引起的肝细胞凋亡的差异,选取毒力差异显著的2株产单核细胞李氏杆菌,建立不同毒力及菌量的小鼠感染模型(A组低剂量攻弱毒、B组半数致死量攻弱毒、C组半数致死量攻强毒、D组过量攻强毒),利用建立的小鼠肝细胞凋亡因子荧光定量PCR方法,检测小鼠肝细胞凋亡途径的重要因子表达量的变化,同时应用TUNEL技术(末端脱氧核苷酸转移酶介导的dUTP缺口末端标记法)检测凋亡情况。TUNEL结果显示,4组小鼠均存在不同程度的肝细胞凋亡,凋亡程度与细菌毒力呈正相关。荧光定量PCR结果显示,死亡受体途径的重要因子Caspase-3和Caspase-8的变化趋势相似,在4组小鼠表达量变化大体呈现相似的趋势(P>0.05),即在感染早期(12h^2d)表达量急剧升高,至峰值后逐渐降低;NF-κB在感染早期升高,且在感染后期也维持在较高的水平;线粒体凋亡途径的重要因子bcl-2、bax组间和组内的变化趋势都不是很明显(P>0.05)。表明产单核细胞李氏杆菌介导的肝细胞凋亡存在剂量及毒力依赖性,并主要依赖死亡受体途径,线粒体凋亡途径在这一过程中并不发挥主要作用。
To explore the mechanism of hepatocyte apoptosis in mice induced by Listeria monocytogenes and compare the difference of apoptosis induced by L.monocytogenes strains with different virulence,L.monocytogenes strains were inoculated to mice and infected models were established(Group A,low-dose attenuated strains;Group B,median lethal dose attenuated strains;Group C,median lethal dose virulent strains;Group D,high-dose virulent strains).Then fluorescent quantitative PCR was established to detect expressions of important apoptosis agents,and at the same time apoptosis conditions were determined by means of terminal dexynucleotidyl transferase-mediated dUTP nick end labeling(TUNEL).In result,the four groups had different degrees of liver apoptosis by TUNEL.Important factors Caspase-3and Caspase-8in the death receptor pathway had almost the same changing trends(P>0.05)in four groups.Namely,in early period of infection(12h-2d)their levels significantly went up to reach a peak value and then gradually moved down.NF-κB expressions increased in the early stage,and still remained high in the late stage.However,the changes of bcl-2and bax,the important factors in the mitochondria-dependent pathway,were not obvious in four groups(P>0.05).So there existed virulent-and dose-dependent of apoptosis in mice liver,mainly through the death receptor pathway rather than the mitochondria-dependent pathway.
出处
《中国兽医科学》
CAS
CSCD
北大核心
2014年第11期1173-1179,共7页
Chinese Veterinary Science
基金
"十一五"国家科技支撑计划重大项目(2010BAD04B01)
