Comparison of Bcl-xL protein expression in placental trophoblast cells between pregnancy complicated by severe preeclampsia and normotensive pregnancy

Abstract

Preeclampsia is one of the main causes of maternal and perinatal mortality and morbidity.
The pathogenesis of preeclampsia remains unclear until now. It is believed that
regulation of apoptosis in trophoblast cells plays an important role in the pathophysiology
of preeclampsia. Failure of spiral arteries remodeling will eventually lead to placental
hypoxia lead to excessive trophoblast apoptosis. The molecular mechanism of apoptosis
is very complicated involving many signaling molecules included Bcl-2 proteins. The Bcl-
2 protein group consists of proapoptosis proteins (Bax) and apoptosis inhibitor proteins
(Bcl-2 and Bcl-xL). The aimed of this stuty was to compare the expression of Bcl-xL
protein in placental trophoblast cells of pregnancy complicated by severe preeclampsia
with that normotensive pregnancy. This study was an observational study with cross
sectional design involving 43 pregnancy patients with severe preeclampsia and 38
normotensive pregnancy who treated in Dr. Sardjito General Hospital, Yogyakarta from
October 2011 until March 2012. Placenta samples were obtained from all subjects for
Bcl-xL protein expression analysis using immunohistochemistry technique. Data were
analyzed using independent t-test, chi-square test, and logistic regression. A p value
<0.05 was considered significant. Significant difference in Bcl-xL protein expression
in trophoblast cells of pregnancy complicated by severe preeclampsia (1.29 ± 0.12)
compared to that normotensive pregnancy (1.71 ± 0.14) was reported (p = 0.00). In
addition, logistic regression test showed that diagnosis of severe preeclampsia had a
statistically significant role in Bcl-xL protein expression (p= 0.000). In conclusion, the
expression of Bcl-xL protein is lower in pregnancy complicated by severe preeclampsia
compared to normotensive pregnancy.