title: Maternal Factors Are Associated with the Expression of Placental Genes Involved in Amino Acid Metabolism and Transport.
abstract: BACKGROUND
  Maternal environment and lifestyle factors may modify placental function to match the mother's capacity to support the demands of fetal growth. Much remains to be understood about maternal influences on placental metabolic and amino acid transporter gene expression. We investigated the influences of maternal lifestyle and body composition (e.g. fat and muscle content) on a selection of metabolic and amino acid transporter genes and their associations with fetal growth.
  
  
  METHODS
  RNA was extracted from 102 term Southampton Women's Survey placental samples. Expression of nine metabolic, seven exchange, eight accumulative and three facilitated transporter genes was analyzed using quantitative real-time PCR.
  
  
  RESULTS
  Increased placental LAT2 (p = 0.01), y+LAT2 (p = 0.03), aspartate aminotransferase 2 (p = 0.02) and decreased aspartate aminotransferase 1 (p = 0.04) mRNA expression associated with pre-pregnancy maternal smoking. Placental mRNA expression of TAT1 (p = 0.01), ASCT1 (p = 0.03), mitochondrial branched chain aminotransferase (p = 0.02) and glutamine synthetase (p = 0.05) was positively associated with maternal strenuous exercise. Increased glutamine synthetase mRNA expression (r = 0.20, p = 0.05) associated with higher maternal diet quality (prudent dietary pattern) pre-pregnancy. Lower LAT4 (r = -0.25, p = 0.05) and aspartate aminotransferase 2 mRNA expression (r = -0.28, p = 0.01) associated with higher early pregnancy diet quality. Lower placental ASCT1 mRNA expression associated with measures of increased maternal fat mass, including pre-pregnancy BMI (r = -0.26, p = 0.01). Lower placental mRNA expression of alanine aminotransferase 2 associated with greater neonatal adiposity, for example neonatal subscapular skinfold thickness (r = -0.33, p = 0.001).
  
  
  CONCLUSIONS
  A number of maternal influences have been linked with outcomes in childhood, independently of neonatal size; our finding of associations between placental expression of transporter and metabolic genes and maternal smoking, physical activity and diet raises the possibility that their effects are mediated in part through alterations in placental function. The observed changes in placental gene expression in relation to modifiable maternal factors are important as they could form part of interventions aimed at maintaining a healthy lifestyle for the mother and for optimal fetal development.
authors.affiliation: Institute of Developmental Sciences, University of Southampton, Tremona Road, Southampton, SO16 6YD, United Kingdom.
authors.forename: Pricilla E
authors.initials: PE
authors.lastname: Day
authors.affiliation: MRC Lifecourse Epidemiology Unit, University of Southampton, Tremona Road, Southampton, SO16 6YD, United Kingdom.
authors.forename: Georgia
authors.initials: G
authors.lastname: Ntani
authors.affiliation: MRC Lifecourse Epidemiology Unit, University of Southampton, Tremona Road, Southampton, SO16 6YD, United Kingdom.
authors.forename: Sarah R
authors.initials: SR
authors.lastname: Crozier
authors.affiliation: MRC Lifecourse Epidemiology Unit, University of Southampton, Tremona Road, Southampton, SO16 6YD, United Kingdom.
authors.forename: Pam A
authors.initials: PA
authors.lastname: Mahon
authors.affiliation: MRC Lifecourse Epidemiology Unit, University of Southampton, Tremona Road, Southampton, SO16 6YD, United Kingdom.
authors.forename: Hazel M
authors.initials: HM
authors.lastname: Inskip
authors.affiliation: MRC Lifecourse Epidemiology Unit, University of Southampton, Tremona Road, Southampton, SO16 6YD, United Kingdom.|NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Tremona Road, Southampton, SO16 6YD, United Kingdom.|NIHR Musculoskeletal Biomedical Research Unit, University of Oxford, Nuffield Orthopedic Centre, Headington, Oxford, OX3 7HE, United Kingdom.
authors.forename: Cyrus
authors.initials: C
authors.lastname: Cooper
authors.affiliation: MRC Lifecourse Epidemiology Unit, University of Southampton, Tremona Road, Southampton, SO16 6YD, United Kingdom.|NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Tremona Road, Southampton, SO16 6YD, United Kingdom.
authors.forename: Nicholas C
authors.initials: NC
authors.lastname: Harvey
authors.affiliation: Institute of Developmental Sciences, University of Southampton, Tremona Road, Southampton, SO16 6YD, United Kingdom.|MRC Lifecourse Epidemiology Unit, University of Southampton, Tremona Road, Southampton, SO16 6YD, United Kingdom.|NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Tremona Road, Southampton, SO16 6YD, United Kingdom.
authors.forename: Keith M
authors.initials: KM
authors.lastname: Godfrey
authors.affiliation: Institute of Developmental Sciences, University of Southampton, Tremona Road, Southampton, SO16 6YD, United Kingdom.|NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Tremona Road, Southampton, SO16 6YD, United Kingdom.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Hanson
authors.affiliation: Institute of Developmental Sciences, University of Southampton, Tremona Road, Southampton, SO16 6YD, United Kingdom.|Institute for Life Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom.
authors.forename: Rohan M
authors.initials: RM
authors.lastname: Lewis
authors.affiliation: Institute of Developmental Sciences, University of Southampton, Tremona Road, Southampton, SO16 6YD, United Kingdom.|Institute for Life Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom.
authors.forename: Jane K
authors.initials: JK
authors.lastname: Cleal
mesh_terms: D000328:Adult; D026905:Amino Acid Transport Systems / Q000235:genetics* / Q000378:metabolism; D000596:Amino Acids / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D004032:Diet; D015444:Exercise; D005260:Female; D015870:Gene Expression; D059647:Gene-Environment Interaction; D006801:Humans; D008019:Life Style; D010920:Placenta / Q000378:metabolism / Q000502:physiology*; D011247:Pregnancy; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D012907:Smoking
chemical_list: D026905:Amino Acid Transport Systems; D000596:Amino Acids; D012333:RNA, Messenger