Caffeine Enhances the Expression of the Angiotensin II Type 2 Receptor mRNA in BeWo Cell Culture and in the Rat Placenta

Abstract

Although chronic caffeine exposure during pregnancy has been shown to affect fetal growth, adverse effects of caffeine on embryogenesis are not only well understood, but also controversial. We have used gene chip technology in an attempt to identify to what extent, if any, caffeine could possibly alter gene expressions in the cytotrophoblast-like cell line BeWo. Few down-regulated genes were found; most of the genes were up-regulated, suggesting that chronic caffeine exposure during the gestational period could exert certain influences on embryogenesis. The highest up-regulated gene expression of BeWo cells by caffeine was angiotensin II type 2 (AT 2) receptor gene. We focused the genes of the renin–angiotensin system (RAS), angiotensin II type 1 (AT 1) and AT 2receptors and angiotensin I converting enzyme, for study on caffeine's responsive gene expression in BeWo cells and in the placentae of pregnant rats that were fed a diet supplemented with caffeine (2 mg/100 g body weight) during gestation, and analysed the gene expressions using RT–PCR and LightCycler™ system. A significantly increased AT 2receptor gene expression and a slight decreased AT 1receptor gene expression demonstrated the caffeine's effect to the placental RAS.