Insulin/IGF, adiponectin and PPAR signalling systems in the placenta

In a large study population of small (SGA), appropriate (AGA) and large-for-gestational-age (LGA)-born infants, placental expression of 22 genes within the insulin/IGF, adiponectin and PPAR signalling systems have been investigated. Substances that showed differential expression between the three study groups were further studied at the protein level by immunohistochemistry in placental tissue, in first-trimester maternal serum and in umbilical cord blood. Our preliminary findings show that placental IGF-1, IGF-2 and IGFBP2 signalling appear to stimulate fetal growth, probably via a common upstream regulator such as nutrition, while the IGF2 receptor appears to be controlled in a different way striving to compensate fetal under- and overgrowth.