Dipeptidyl peptidase IV reduces trophoblast invasion by inhibiting the activity of MMPs.

Preeclampsia is a severe pregnancy complication in part due to insufficient implantation. This study aimed at elucidating the mechanism of action of dipeptidyl peptidase IV (DPPIV) in preeclampsia. Small activating RNAs (saRNA) were used to upregulate DPPIV expression in human trophoblast JAR cells. The DPPIV expression level was analyzed by real-time quantitative PCR and western blot and its activity was measured by luminescent protease assay. MMP-9 activity was analyzed by zymography and cell invasion by matrigel invasion assay. DPPIV expression level and activity was significantly increased by saRNA in JAR cells. DDPIV specific inhibitor diprotin A inhibited its activity at both basal and activated levels. DPPIV did not regulate MMP-9 expression but did repress MMP-9 activity. The invading ability of JAR cells was reduced by saRNA but increased by diprotin A. DPPIV might be responsible for the shallow implantation of the placenta due to its inhibition of the invading ability of extravillous trophoblasts, causing preeclampsia at later stage of pregnancy.