Spatial and temporal patterns of expression of messenger RNA for insulin-like growth factors and their binding proteins in the placenta of man and laboratory animals

Citation
Vkm. Han et Am. Carter, Spatial and temporal patterns of expression of messenger RNA for insulin-like growth factors and their binding proteins in the placenta of man and laboratory animals, PLACENTA, 21(4), 2000, pp. 289-305
Citations number
92
Categorie Soggetti
Reproductive Medicine","da verificare
Journal title
PLACENTA
ISSN journal
01434004 → ACNP
Volume
21
Issue
4
Year of publication
2000
Pages
289 - 305
Database
ISI
SICI code
0143-4004(200005)21:4<289:SATPOE>2.0.ZU;2-1
Abstract
To better understand the role of the insulin-like growth factors (IGF- I an d -II) and their binding proteins (IGFBPs 1-6) in placental development and function, it is important to review similarities and differences between s pecies in expression of the respective mRNAs. In human placenta, IGF-II mRN A is expressed in chorionic mesoderm and first trimester villous cytotropho blast, but not in syncytiotrophoblast. In contrast, in rhesus monkey placen ta, IGF-II mRNA is expressed in syncytiotrophoblast but not in chorionic me soderm. IGFBP-3 mRNA is present in the chorionic mesoderm of placental vill i from both these species and may modulate IGF-II action through a paracrin e mechanism. In rodent placentae, IGF-II mRNA is expressed both in fetal me soderm and in the trophoblast of the placental labyrinth. In guinea pig, wh ere IGFBP-5 mRNA is expressed in the marginal and interlobular syncytium an d IGF-PI mRNA in the labyrinth, interaction between IGF-II and IGFBP-5 mRNA may be involved in vascularization of the placenta by fetal vessels. In sh eep placenta, IGF-II mRNA is expressed, not in the trophoblast layer, but i n the fetal mesoderm immediately adjacent to it. In the basal plate of huma n, rhesus monkey and baboon placentae, extravillous trophoblasts express IG F-II mRNA and uterine decidual cells IGFBP 1-6 mRNAs. The inference is that there is interaction between IGF-II and IGFBPs at the maternal-fetal inter face of the primate placenta during trophoblast invasion and decidualizatio n. IGFBP-1 expressed by the decidua may also interact with alpha(5)beta(1) integrin expressed by the extravillous trophoblast. The placentae of rodent s are also of the invasive type. Glycogen cells of the mouse placenta are a nalogous with human extravillous trophoblast and express IGF-II mRNA. Howev er, expression of IGFBP mRNAs in the mouse, as in the guinea pig, is confin ed to non-decidualized endometrium and myometrium. IGF-II mRNA is strongly expressed by trophoblasts invading uterine vessels in human and guinea pig placentae. Interactions probably occur between IGF-II expressed by these tr ophoblasts and IGFBPs expressed in the vessel walls. However, it is possibl e that IGFBPs expressed by maternal vessels are associated with processes t hat are independent of trophoblast invasion. Thus, IGFBP-3 mRNA is highly e xpressed in the maternal blood vessels of the non-deciduate sheep placenta. Findings to date highlight the diversity in the expression of the IGF syst em among placentae of man and different laboratory animals, and even betwee n closely related species. Comparative studies will continue to be required to understand the functional role of IGFs and IGFBPs in each species. (C) 2000 Harcourt Publishers Ltd.