title: Placental mTOR links maternal nutrient availability to fetal growth.
abstract: The mTOR (mammalian target of rapamycin) signalling pathway functions as a nutrient sensor, both in individual cells and, more globally, in organs such as the fat body in Drosophila and the hypothalamus in the rat. The activity of placental amino acid transporters is decreased in IUGR (intrauterine growth restriction), and recent experimental evidence suggests that these changes contribute directly to the restricted fetal growth. We have shown that mTOR regulates the activity of the placental L-type amino acid transporter system and that placental mTOR activity is decreased in IUGR. The present review summarizes the emerging evidence implicating placental mTOR signalling as a key mechanism linking maternal nutrient and growth factor concentrations to amino acid transport in the human placenta. Since fetal growth is critically dependent on placental nutrient transport, placental mTOR signalling plays an important role in the regulation of fetal growth.
authors.affiliation: Perinatal Center, Department of Physiology, Institute of Neuroscience and Physiology, University of Gothenburg, P.O. Box 432, SE-405 30 Gothenburg, Sweden. sara.roos@gu.se
authors.forename: Sara
authors.initials: S
authors.lastname: Roos
authors.forename: Theresa L
authors.initials: TL
authors.lastname: Powell
authors.forename: Thomas
authors.initials: T
authors.lastname: Jansson
mesh_terms: D000818:Animals; D005260:Female; D047109:Fetal Development; D005502:Food; D006801:Humans; D008431:Maternal-Fetal Exchange; D010920:Placenta / Q000201:enzymology*; D011247:Pregnancy; D011494:Protein Kinases / Q000378:metabolism*; D015398:Signal Transduction; D058570:TOR Serine-Threonine Kinases
chemical_list: D011494:Protein Kinases; C546842:MTOR protein, human; C546845:mTOR protein, rat; D058570:TOR Serine-Threonine Kinases