Proceedings of The Physiological Society

University College Cork (2004) J Physiol 560P, C16

Communications

EFFECT OF EARLY TO MID GESTATION NUTRIENT RESTRICTION ON UNCOUPLING PROTEIN-2 nullMnullRNA ABUNDANCE IN THE OVINE FETAL PLACENTA AND ADOLESCENT LUNG.

Gnanalingham,Giritharalingham Muhuntha; Dandrea,Jennifer ; Gopalakrishnan,Gosala S; Bispham,Jayson ; Budge,Helen ; Symonds,Michael E; Stephenson,Terence ;

1. Centre for Reproduction and Early Life, University of Nottingham, Nottingham, United Kingdom.


  • mRNA abundance in Fetal Placenta and Adolescent Lung

    Significantly different from age matched controls:*p<0.05 **p<0.01

Maternal nutrient restriction has marked effects on the developing fetus, including upregulation of glucocorticoid receptor (GCR) mRNA in a range of fetal tissues, including the lung (Whorwood et al. 2001). Uncoupling protein (UCP)-2 is a member of the inner mitochondrial protein superfamily, whose exact function is not known. Postulated roles include the modulation of reactive oxygen species (ROS) and apoptosis, and immune regulation (Arsenijevic et al. 2000). The effect of maternal nutrient restriction in early to mid gestation, coincident with the period of maximal placental growth, on UCP2 and GCR mRNA abundance in the ovine fetal placenta and adolescent lung has not been determined. Fetal placental tissue was sampled at 80 or 140 days (term ≅147 days) gestation after humane euthanasia from nutrient restricted (NR) singleton-bearing ewes, receiving 60% of their metabolisable energy requirements (MER) from 28 to 80 days gestation, or Controls (C) receiving 100-150% MER (n=5 per group). All ewes were fed to meet their MER up to term. Lung tissue was also sampled from humanely killed adolescent offspring at 6 months born to NR singleton-bearing ewes (n=5 per group). Total RNA was isolated and mRNA abundance was measured by RT-PCR using oligonucleotide primers designed specifically to ovine UCP2 and GCR. Results are given as means (±SEM) relative to 18S rRNA. Statistical differences between groups were analysed by Mann-Whitney U test. Fetal placental weights decreased in the NR group (C 507.8±64; NR 326.2±20.3g, p<0.05) at 80 days, but increased at 140 days (C 183.6±9.6; NR 364.4±21.3g, p<0.05) compared to C. Lung fresh and dry weights, and total protein concentration were similar between groups. UCP2 and GCR mRNA abundance in fetal placenta increased with gestational age and with nutrient-restriction in mid-gestation. UCP2 mRNA levels were low in the adolescent lung but increased by NR. Maternal nutrient restriction in early to mid gestation increases UCP2 mRNA abundance in the fetal placenta and adolescent lung. These changes may be important in modulating ROS and apoptosis and may indicate long-term susceptibility to infection in the offspring.

Where applicable, experiments conform with Society ethical requirements