Vaspin and amylin are expressed in human and rat placenta and regulated by nutritional status

Amylin (islet amyloid polypeptide) and vaspin (visceral adipose tissue specific serpin) are gut and adipocyte hormones involved in the regulation of body weight homeostasis. The aim of this study was to examine whether amylin and vaspin are expressed in human and rat placenta, as well as their regulation by nutritional status. Our results demonstrate that amylin and vaspin are localized in both human and rat placenta. In the rat term placenta vaspin was demonstrated in the trophoblast of the fetal villi, the labyrinth. Vaspin immunostaining in human placenta was localized in cytotrophoblast and syncytiotrophoblast in the first trimester placentas while in the third trimester vaspin was localized in the syncytiotrophoblast. Regarding amylin, rat placenta of 16 days of gestational age showed an intense immunostaining, mainly localized in the labyrinth. On the other hand, in the human third trimester placenta amylin immunoreactivity was intense in the syncytiotrophoblast of the chorionic villi and in decidual cells. Furthermore, placental amylin and vaspin showed an opposite pattern of expression during pregnancy, with vaspin showing the highest expression level at the end and amylin at the beginning of pregnancy. Finally, food restriction also has contrary effects on their expression, increasing vaspin but decreasing amylin placental mRNA and protein levels. Taken together, our results demonstrate that vaspin and amylin are modulated by energy status in the placenta, which suggests that these proteins may be involved in the regulation of placental metabolic functions.