Different expression of placental pyruvate kinase in normal, preeclamptic and intrauterine growth restriction pregnancies

Abstract

IntroductionPreeclampsia (PE) and intrauterine growth restriction (IUGR) are two diseases that affect pregnant women and their unborn children. These diseases cause low birth weight, pre-term delivery, and neurological and cardiovascular disorders in babies. Combined they account for 20% of preterm deliveries. Pyruvate kinase M2 (PKM2) is a metabolism enzyme found in developing embryonic and cancer tissues. Our objective is to determine the expression of PKM2 in human PE and IUGR compared to normal pregnancies. Understanding expression of PKM2 in PE and IUGR could help us to better understand the mechanisms and find treatments for PE and IUGR. MethodsHuman placental tissues were obtained for PKM2 determination and analyzed by immunohistochemistry, Western blot, and a pyruvate assay. Placental samples were homogenized and cytoplasmic and nuclear proteins were extracted for Western blot analysis. ResultsPreeclampsia samples had elevated levels of p-PKM2, p-ERK, and ERK in the cytoplasm. Beta-catenin and lactose dehydrogenase (LDH) were also elevated in preeclampsia placenta samples. Discussion and conclusionWe conclude that PKM2 is expressed in normal, PE and IUGR pregnancies. Also, that this expression is increased in the PE placenta at delivery. These results suggest placental metabolism through PKM2 could play a role in human preeclampsia.