Mou Rong, Bao Huai-En, Zhang Ke, Wu Jia-Hong, Lang Shu-Yuan
Department of Parasitology, Guiyang Medical College, Guiyang 550004, China.
Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi. 2012 Oct 30;30(5):367-72.
To investigate apoptosis in liver tissue of the domestic pigs infected with eggs of Taenia asiatica and Taenia saginata.
The adult worms of T. asiatica and T. saginata were collected and identified from the taeniasis patients in Dunyun and Congjiang districts, Guizhou province. Eggs were collected from gravid proglottids and prepared by washing and centrifugation. Nineteen 20-day hybrid domestic pigs (Duroc-Yorkshire-Landrace strain) were randomly divided into T. asiatica group (6 pigs), T. saginata group (8 pigs) and control group (5 pigs). Each animal of experimental groups was infected with 1.5 x 10(5) eggs by stomach injection. On day 15, 32, 46 and 74 after infection, animals were sacrificed and liver samples were collected for further experiments. The liver tissues were sliced for glass slides and prepared for ultrathin sections. The apoptosis of hepatocytes was identified by terminal deoxynucleotidyl transferase-mediated dUTP nick and labeling. The morphological features of liver tissue were observed under transmission electron microscope.
The infection rate of two experiment groups reached 100%. Better developed cysticerci were found in liver of T. asiatica group than that of T. saginata group, but the liver pathological changes caused by cysticerci were similar. On day 15 and 32 after infection, hydropic degeneration, obvious vacuolization and some balloon-like degeneration were found in hepatocytes, and focal hepatic necrosis was observed. On day 46, spotty necrosis occurred in some local liver tissues. On day 74, main damages were granulomatous reactions surrounding cysticercus and focal liver fibrosis. On day 46, apoptosis index in T. asiatica group [(15.07 +/- 3.42)6%] and T. saginata group [(17.13 +/- 1.62)5%] was considerably higher than that in the control [(9.53 +/- 1.06)%] (P < 0.05). On day 74, apoptosis index in T. asiatica group [(27.33 +/- 0.92)5%] and T. saginata group [(34.20 +/- 0.73)%] was higher than that in the control [(13.60 +/- 2.26)%] (P < 0.05), and the apoptosis index in T. saginata group was significantly higher than that of T. asiatica group (P < 0.05). Simultaneously, morphological characteristics of apoptosis were clearly observed in hepatocytes in two experimental groups, showing shrunken, wrinkled and deformed nucleus with consolidation of chromosomes and appearance of apoptotic body.
The hepatocyte apoptosis of domestic pig is induced in the middle and late stages of infection by the cysticerci of T. asiatica and T. saginata, indicating that hepatic apoptosis might be related to focal liver fibrosis of the host caused by the cysticerci.
研究亚洲带绦虫和牛带绦虫虫卵感染家猪肝脏组织中的细胞凋亡情况。
从贵州省都匀和从江地区的绦虫病患者体内采集亚洲带绦虫和牛带绦虫成虫并进行鉴定。从妊娠节片中收集虫卵，经清洗和离心处理后备用。将19头20日龄的杜洛克-约克夏-长白杂交家猪随机分为亚洲带绦虫组（6头）、牛带绦虫组（8头）和对照组（5头）。实验组的每只动物经胃内注射1.5×10⁵个虫卵。在感染后第15、32、46和74天，处死动物并采集肝脏样本用于进一步实验。将肝脏组织切片制成玻片并制备超薄切片。通过末端脱氧核苷酸转移酶介导的dUTP缺口末端标记法鉴定肝细胞凋亡情况。在透射电子显微镜下观察肝脏组织的形态学特征。
两个实验组的感染率均达到100%。亚洲带绦虫组肝脏中发现的囊尾蚴发育较牛带绦虫组更好，但囊尾蚴引起的肝脏病理变化相似。感染后第15天和32天，肝细胞出现水样变性、明显空泡化和一些气球样变性，并观察到局灶性肝坏死。第46天，部分局部肝脏组织出现点状坏死。第74天，主要损伤为围绕囊尾蚴的肉芽肿反应和局灶性肝纤维化。第46天，亚洲带绦虫组[（15.07±3.42）%]和牛带绦虫组[（17.13±1.62）%]的凋亡指数显著高于对照组[（9.53±1.06）%]（P<0.05）。第74天，亚洲带绦虫组[（27.33±0.92）%]和牛带绦虫组[（34.20±0.73）%]的凋亡指数高于对照组[（13.60±2.26）%]（P<0.05），且牛带绦虫组的凋亡指数显著高于亚洲带绦虫组（P<0.05）。同时，在两个实验组的肝细胞中均清晰观察到凋亡的形态学特征，表现为细胞核皱缩、变形，染色体固缩，出现凋亡小体。
亚洲带绦虫和牛带绦虫的囊尾蚴在感染中晚期诱导家猪肝细胞凋亡，提示肝脏细胞凋亡可能与囊尾蚴引起的宿主局灶性肝纤维化有关。
