title: Effects on transcriptional regulation and lipid droplet characteristics in the liver of female juvenile pigs after early postnatal feed restriction and refeeding are dependent on birth weight.
abstract: Epidemiological and experimental data indicate that caloric restriction in early postnatal life may improve liver lipid metabolism in low birth weight individuals. The present study investigated transcriptional and metabolic responses to low (U) and normal (N) birth weight (d 75, T1) and postnatal feed restriction (R, 60% of controls, d 98, T2) followed by subsequent refeeding until d 131 of age (T3). Liver tissue studies were performed with a total of 42 female pigs which were born by multiparous German landrace sows. Overall, 194 genes were differentially expressed in the liver of U vs. N (T1) animals with roles in lipid metabolism. The total mean area and number of lipid droplets (LD) was about 4.6- and 3.7 times higher in U compared to N. In U, the mean LD size (µm(2)) was 24.9% higher. 3-week feed restriction reduced total mean area of LDs by 58.3 and 72.7% in U and N, respectively. A functional role of the affected genes in amino acid metabolism was additionally indicated. This was reflected by a 17.0% higher arginine concentration in the liver of UR animals (vs. NR). To evaluate persistency of effects, analyses were also done after refeeding period at T3. Overall, 4 and 22 genes show persistent regulation in U and N animals after 5 weeks of refeeding, respectively. These genes are involved in e.g. processes of lipid and protein metabolism and glucose homeostasis. Moreover, the recovery of total mean LD area in U and N animals back to the previous T1 level was observed. However, when compared to controls, the mean LD size was still reduced by 23.3% in UR, whereas it was increased in NR (+24.7%). The present results suggest that short-term postnatal feed restriction period programmed juvenile U animals for an increased rate of hepatic lipolysis in later life.
authors.affiliation: Institute of Nutritional Physiology 'Oskar Kellner', Leibniz Institute for Farm Animal Biology (FBN), Dummerstorf, Germany.
authors.forename: Constance
authors.initials: C
authors.lastname: Nebendahl
authors.forename: Ricarda
authors.initials: R
authors.lastname: Krüger
authors.forename: Solvig
authors.initials: S
authors.lastname: Görs
authors.forename: Elke
authors.initials: E
authors.lastname: Albrecht
authors.forename: Karen
authors.initials: K
authors.lastname: Martens
authors.forename: Steffen
authors.initials: S
authors.lastname: Hennig
authors.forename: Niels
authors.initials: N
authors.lastname: Storm
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Höppner
authors.forename: Ralf
authors.initials: R
authors.lastname: Pfuhl
authors.forename: Barbara U
authors.initials: BU
authors.lastname: Metzler-Zebeli
authors.forename: Harald M
authors.initials: HM
authors.lastname: Hammon
authors.forename: Cornelia C
authors.initials: CC
authors.lastname: Metges
mesh_terms: D000818:Animals; D001724:Birth Weight / Q000502:physiology*; D005247:Feeding Behavior / Q000502:physiology*; D005260:Female; D005786:Gene Expression Regulation / Q000502:physiology*; D050356:Lipid Metabolism / Q000502:physiology*; D008099:Liver / Q000502:physiology*; D013552:Swine; D014158:Transcription, Genetic / Q000502:physiology*