刚地弓形虫感染对孕鼠细胞凋亡的影响

目的 探讨刚地弓形虫对孕鼠胎盘细胞凋亡及其相关基因bax、bcl-2表达的影响。方法 建立刚地弓形虫感染的孕鼠模型，采用胎盘组织压片及病理切片，观察胎盘组织的损伤情况；采用DNA缺口末端标记技术（TUNEL）检测胎盘细胞的凋亡情况；采用免疫组织化学法（SP法）观察细胞凋亡调控基因bax和bcl-2在胎盘细胞中的表达。结果 与对照组相比，随着感染时间的延长，感染组胎盘组织压片中可见弓形虫虫体逐渐增加，HE染色可见有大量的淋巴细胞浸润及凋亡小体；TUNEL证实感染组胎盘滋养层细胞凋亡显著增强（P〈0．05）；免疫组织化学结果显示，感染组胎盘滋养层细胞凋亡相关基因bax表达显著增强、bcl-2表达减弱（P〈0．05）。结论 刚地弓形虫侵入胎盘组织，可通过上调滋养层细胞bax基因表达，下调bcl-2基因表达而诱导胎盘滋养层细胞凋亡增加，从而影响胎盘组织结构和功能，导致不良妊娠。

Effect of Toxoplasma gondii on apoptosis of placental cell in pregnant mice

Objective To investigate the effect of Toxoplasma gondii on apoptosis and the expression of bcl-2 and bax protein in placental trophoblastic cell of pregnant mice. Methods Experimental model was established by intraperitoneal injection of tachyzoites of T. gondii. The morphological changes of the placenta were detected by microscopical examination on slides stained with hematoxylin and eosin (HE). The apoptosis of placental cell was measured using terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) techniques, the expression of bax and bcl-2 protein was detected by immunohistochemistry techniques in placenta of control and experiment groups. Results Along with gestational period, the number of the parasites increased gradually in placenta. Inflammatory reaction and apoptotic bodies were shown in placenta in experiment groups. Compared with the control, the apoptosis was identified obviously in the trophoblast cells in experiment groups. The expression of bax protein in the placenta of experiment group was significantly higher than that of the control group, whereas the expression of bcl-2 in the placenta of the experiment group was lower than that of the control group(P<0.05). Conclusion T. gondii might induce apopotosis by upregulating the expression of bax and downregulating the expression of bcl-2, which influence the natural structure and function of placenta, and increase the possibility of abnormal pregnancy.