特发性胎儿生长受限与胎盘细胞凋亡及bcl-2基因表达的关系

Roles of placental cellular apoptosis and bcl-2 expression in fetal growth restriction with unclear etiologies

目的探讨特发性胎儿生长受限（FGR）与胎盘细胞凋亡及bcl-2基因表达的关系。方法应用透射电镜、脱氧核苷酸末端转移酶介导的脱氧尿苷三磷酸标记法（TUNEL）、流式细胞技术（FCM）检测特发性FGR孕妇（FGR组）及正常妊娠妇女（对照组）各15例的胎盘细胞凋亡情况，并采用RT-PCR技术观察两组胎盘细胞中bcl-2基因相对表达量。结果电镜下观察到FGR组胎盘合体滋养细胞核膜皱缩，核仁消失，染色质致密、凝聚；TUNEL检测FGR组胎盘细胞凋亡率为13．68％，高于对照组的4．05％，两组比较，差异有统计学意义（P〈0．05）；FCM检测胎盘S期细胞比率FGR组为3．4％，对照组为2．2％，两组比较，差异有统计学意义（P〈0．05），FCM检测的胎盘细胞凋亡率变化趋势与TUNEL检测结果一致；FGR组胎盘细胞bcl-2基因相对表达量为0．19±0．13，对照组为0．55±0．17，两组比较，差异也有统计学意义（P〈0．05）。结论特发性FGR的发生与胎盘细胞凋亡增加有关，胎盘细胞凋亡增加与胎盘细胞中bcl-2基因表达下调有一定关系。

Objective To investigate the roles of placental cellular apoptosis and bcl-2 gene expression in fetal growth restriction （FGR） with unclear etiologies. Methods The placental tissues of 15 FGR and 15 parallel normal pregnancies were included in the study. Apoptosis were evaluated by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling （TUNEL） assay, transmission electron microscopy and flow cytometry assay （FCM）. Expression of bcl-2 was determined by RT-PCR. Results In ceils from FGR placentas, but not in control normal ceils, typical features of apoptosis were observed, including internucleosomal DNA degradation, and both nuclear （nuclear condensation and fragmentation） and extranuclear （cell blabbing） morphological alterations. The placental cellular apoptosis were also confirmed at a rate of 13.68% by TUNEL assay and 10. 58% by FCM in FGR group, compared to 4.05% and 3.88% in the normal tissues. Meanwhile, bcl-2 expression level was lower in FGR group （0. 19 ±0. 13） than in the normal group （0.55 ±0. 17）. Conclusion Apoptosis may play an important role in the pathogenesis of FGR and may be related with to lowered expression of bcl-2.