Epidermal growth factor and insulin-like growth factor I differently influence the directional accumulation and transfer of 2-aminoisobutyrate (AIB) by human placental trophoblast in two-sided culture.
We examined the effects of epidermal growth factor (EGF) and insulin-like growth factor I (IGF-I) on the uptake of AIB by and its transfer across near-term human placental syncytiotrophoblast in two-sided culture. Pre-incubation of the trophoblast cell layer with either EGF (50ng/ml) or IGF-I (100ng/ml) on the apical (microvillous, in vivo maternal-facing) side reduced rates of unidirectional microvillous-to-basal transtrophoblast AIB transfer, increasing AIB retention within the cells. EGF on the basal (fetal-facing) side of the cell layer enhanced AIB uptake from the microvillous side but also increased overall mediated permeability in both directions. IGF-I at the basal surface, however, increased AIB uptake across the microvillous membrane, and induced a backflux from the cells into the basal medium dependent upon basal AIB concentration, suggesting that in vivo IGF-I on the fetal side enhances maternal-to-fetal placental transfer. The ideas are consistent with current concepts of maternal-placental and fetal-placental interactions regulating pregnancy and fetal development.
Bloxam
D L
DL
Reproductive Biology Laboratory, Royal Postgraduate Medical School Institute of Obstetrics and Gynaecology, Queen Charlotte's and Chelsea Hospital, London, United Kingdom.
Bax
B E
BE
Bax
C M
CM
D000621:Aminoisobutyric Acids / Q000378:metabolism*; D001692:Biological Transport / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004815:Epidermal Growth Factor / Q000494:pharmacology* / Q000502:physiology; D005260:Female; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology* / Q000502:physiology; D007700:Kinetics; D008871:Microvilli / Q000187:drug effects / Q000378:metabolism; D011247:Pregnancy; D014327:Trophoblasts / Q000187:drug effects / Q000378:metabolism*
D000621:Aminoisobutyric Acids; C100049:2-aminoisobutyric acid; D004815:Epidermal Growth Factor; D007334:Insulin-Like Growth Factor I