Changes in placental dipeptidyl peptidase IV in preeclampsia with intrauterine growth restriction.

The purpose of this study was to examine alterations in placental expression of dipeptidyl peptidase IV (DPPIV). The localization of DPPIV was compared in control and preeclamptic placentas. Enzyme activity, mRNA, and protein expression were also measured. In term placentas, DPPIV was expressed preferentially in the fetal vascular endothelial cells within stem villi and only weakly in the villous stromal cells. DPPIV activity in control placentas showed no remarkable changes throughout gestation. Levels of activity in samples from normotensive control cases and women having preeclampsia with or without intrauterine growth restriction were 11.8 ′ 2.1, 13.4 ′ 1.1, and 15.3 ′ 0.62 pmol pNA/min/mg protein, respectively. The preeclamptic placentas with intrauterine growth restriction thus showed significantly higher levels of activity than the controls (p < 0.05). We propose that placental DPPIV influences fetal metabolism via the degradation of fetoplacental circulating bioactive peptides, including incretins, resulting in the regulation of fetal growth.