Zhang Yan, Zheng Ming-xue, Xu Zhi-yong, Xu Huan-cheng, Cui Xiao-zhen, Yang Sha-sha, Zhao Wen-long, Li Shan, Lv Qiang-hua, Bai Rui
College of Animal Science and Technology, Shanxi Agricultural University, Taigu, 030801, China.
College of Animal Science and Technology, Shanxi Agricultural University, Taigu, 030801, China
Poult Sci. 2015 Dec;94(12):2970-9. doi: 10.3382/ps/pev293. Epub 2015 Oct 13.
Coccidiosis causes considerable economic losses in the poultry industry. At present, the pathology of coccidiosis is preventable with anticoccidials and vaccination, although at considerable cost to the international poultry industry. The purpose of the present study was to elucidate the relationship between Eimeria tenella development and host cell apoptosis in chickens, which provides a theoretical basis for further study of the injury mechanism of E. tenella and the prevention and treatment of coccidiosis. Cecal epithelial cells from chick embryo were used as host cells in vitro. In addition, flow cytometry, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP) nick-end labeling, and histopathological assays were used to detect the dynamic changes in E. tenella infection rates, DNA injury rates, and apoptosis rates in groups treated with and without the caspase-9 inhibitor Z-LEHD-FMK. Following E. tenella infection, we demonstrated that untreated cells had less apoptosis at 4 h and, inversely, more apoptosis at 24 to 120 h compared with control cells. Furthermore, after the application of Z-LEHD-FMK, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assays, and translation of phosphatidyl serines to the host cell plasma membrane surface, the treated group chick embryo cecal epithelial cells exhibited decreased apoptosis and DNA injuries (P<0.01) at 24 to 120 h. However, light microscopy showed that E. tenella infection rates of treated cells were higher (P<0.01) than untreated cells during the whole experimental period. Together, these observations suggest that E. tenella can protect host cells from apoptosis at early stages of development but can promote apoptosis during the middle to late stages. In addition, the inhibition of host cell apoptosis can be beneficial to the intracellular growth and development of E. tenella.
球虫病给家禽业造成了巨大的经济损失。目前，尽管给国际家禽业带来了相当大的成本，但球虫病的病理可以通过抗球虫药和疫苗接种来预防。本研究的目的是阐明鸡柔嫩艾美耳球虫发育与宿主细胞凋亡之间的关系，为进一步研究柔嫩艾美耳球虫的损伤机制及球虫病的防治提供理论依据。鸡胚盲肠上皮细胞被用作体外宿主细胞。此外，采用流式细胞术、末端脱氧核苷酸转移酶介导的脱氧尿苷三磷酸（dUTP）缺口末端标记法和组织病理学检测方法，检测有无半胱天冬酶-9抑制剂Z-LEHD-FMK处理组中柔嫩艾美耳球虫感染率、DNA损伤率和凋亡率的动态变化。在柔嫩艾美耳球虫感染后，我们发现与对照细胞相比，未处理的细胞在4小时时凋亡较少，而在24至120小时时凋亡较多。此外，在应用Z-LEHD-FMK、进行末端脱氧核苷酸转移酶介导的dUTP缺口末端标记检测以及磷脂酰丝氨酸向宿主细胞质膜表面的转位后，处理组鸡胚盲肠上皮细胞在24至120小时时凋亡和DNA损伤减少（P<0.01）。然而，光学显微镜显示，在整个实验期间，处理组细胞的柔嫩艾美耳球虫感染率高于未处理组细胞（P<0.01）。综上所述，这些观察结果表明，柔嫩艾美耳球虫在发育早期可保护宿主细胞免于凋亡，但在中后期可促进凋亡。此外，抑制宿主细胞凋亡可能有利于柔嫩艾美耳球虫在细胞内的生长和发育。
