Objective: To determine the apoptosis in placenta tissues of patients with hypertensive disorder complicating pregnancy and its relationship with Bcl-2, TGFbeta1, and to explore the etiology of hypertensive disorder complicating pregnancy.
Methods: Forty-five placenta samples were obtained from pregnancies with hypertensive disorder (15 gestational hypertension, 15 mild preeclampsia, and 15 severe preeclampsia) and 45 normal placenta tissues were enrolled from the third-trimester pregnancies. Immunohistochemistry (SP method) was used to study the expression of Bcl-2 and TGFbeta1 in human trophoblasts. Terminal deoxynucleotidyl transferase-dUTP nick end-labeling (TUNEL) was used to quantify the incidence of apoptosis in human trophoblasts.
Results: The apoptosis rate and TGFbeta1 expression in hypertensive disorder complicating pregnancy group was higher than that in the control group, but the Bcl-2 expression was significantly lower than the control group (all Ps<0.01). With the aggravation of this illness, the apoptosis rate and TGFbeta1 expression in the gestational hypertension group, mild preeclampsia group, and severe preeclampsia tended to be increasing, but the Bcl-2 expression was decreasing (P<0.001). The apoptosis of placenta villi and TGFbeta1 expression were positively correlated in the severe preeclampsia group and mild preeclampsia group,but the apoptosis of placenta villi and Bcl-2 were negatively correlated (all Ps<0.05). TGFbeta1 and Bcl-2 expressions in the severe preeclampsia group and mild preeclampsia group were negatively correlated (P<0.05).
Conclusion: Apoptosis of the placental trophoblasts of pregnancies with hypertensive disorder is evidently enhanced. The TGFbeta1 expression increases and the Bcl-2 expression decreases. The imbalance between TGFbeta1 and Bcl-2 expression may induce the hypertensive disorder.