自由生活阿米巴成囊过程中的自噬变化  

Changes of autophagy during encystation of free-living amoeba

作　　者：王南宁[1] 谭玉珍[1] 王海杰[1] 

机构地区：[1]复旦大学上海医学院人体解剖学与组织学胚胎学系,上海200032

出　　处：《解剖学报》2011年第4期509-512,共4页Acta Anatomica Sinica

基　　金：国家自然科学基金资助项目(30570948)

摘　　要：目的探讨自由生活阿米巴由滋养体向包囊转变过程中的自噬变化。方法通过撤除大肠埃希菌培养基,诱导滋养体转变为包囊,分别在24 h、36 h和48 h时进行观察。在扫描电子显微镜下观察阿米巴成囊过程中的形态学变化,透射电镜下观察阿米巴自噬的变化及各种自噬结构的结构特点,图像分析仪测量自噬结构的断面面积。用单丹磺酰尸胺(MDC)染色法标记阿米巴虫体内的自噬体,在激光扫描共焦显微镜下观察和定量分析。结果对照组阿米巴虫体内充满细菌碎片,发生轻微的自噬,自噬结构数目较少。与对照组比较,成囊24 h组阿米巴自噬水平显著提高,自噬结构数目增多,自噬前体、自噬体和自噬溶酶体与细胞质的断面面积比增大;成囊36 h组阿米巴自噬水平显著降低,自噬结构数目减少;成囊48 h组阿米巴92%转变为包囊,虫体内未见自噬结构。结论自由生活阿米巴在由滋养体向包囊转变的早期,虫体内自噬功能显著增强,随后逐渐降低。Objective To investigate autophagic changes of free-living amoeba during transformation from trophozoites to cysts. Methods Trophozoites were induced to form cysts with withdrawing of E. coli from the medium. Autophagic changes of the amoeba were investigated on 24hours, 36hours and 48hours after induction, the morphological changes of amoeba during encystation were viewed with a scanning electron microscope, The autophagic structures in amoeba were examined with a transmission electron microscope, cross-section areas of the autophagic structures were measured with an image analyzer. The autophagosomes of amoeba were labeled with monodansylcadaverine （MDC） staining and counted under confocal laser scanning microscope. Results In the control group, amoeba was full of fragment of E. coli, the level of autophagy was low. There were few autophagic structures in amoeba. Comparing with the control group, the autophagic level of amoeba after induction for 24 hours was enhanced significantly. Number of autophagic structures increased, the ratios of the cross-sectional areas of the autophagic precursors, autophagosomes and autophagolysosomes to that of the cytoplasm of amoeba were higher. The level of autophagy was attenuated significantly and number of autophagic structures decreased after induction for 36 hours. After induction for 48 hours, 92% trophozoites were transform to cysts, no autophagic structures were observed. Conclusion During encystation, autophagic activities of amoeba increased significantly in the early phase and decreaed in the later phase gradually.

关 键 词：滋养体 成囊 自噬 扫描电镜 透射电镜 阿米巴 

分 类 号：R361.3[医药卫生—病理学]