title: The liver X-receptor gene promoter is hypermethylated in a mouse model of prenatal protein restriction.
abstract: Prenatal nutrition as influenced by the nutritional status of the mother has been identified as a determinant of adult disease. Feeding low-protein diets during pregnancy in rodents is a well-established model to induce programming events in offspring. We hypothesized that protein restriction would influence fetal lipid metabolism by inducing epigenetic adaptations. Pregnant C57BL/6J mice were exposed to a protein-restriction protocol (9% vs. 18% casein). Shortly before birth, dams and fetuses were killed. To identify putative epigenetic changes, CG-dinucleotide-rich region in the promoter of a gene (CpG island) methylation microarrays were performed on DNA isolated from fetal livers. Two hundred four gene promoter regions were differentially methylated upon protein restriction. The liver X-receptor (Lxr) alpha promoter was hypermethylated in protein-restricted pups. Lxr alpha is a nuclear receptor critically involved in control of cholesterol and fatty acid metabolism. The mRNA level of Lxra was reduced by 32% in fetal liver upon maternal protein restriction, whereas expression of the Lxr target genes Abcg5/Abcg8 was reduced by 56% and 51%, respectively, measured by real-time quantitative PCR. The same effect, although less pronounced, was observed in the fetal intestine. In vitro methylation of a mouse Lxra-promoter/luciferase expression cassette resulted in a 24-fold transcriptional repression. Our study demonstrates that, in mice, protein restriction during pregnancy interferes with DNA methylation in fetal liver. Lxra is a target of differential methylation, and Lxra transcription is dependent on DNA methylation. It is tempting to speculate that perinatal nutrition may influence adult lipid metabolism by DNA methylation, which may contribute to the epidemiological relation between perinatal/neonatal nutrition and adult disease.
authors.affiliation: Center for Liver, Digestive and Metabolic Diseases, Laboratory of Pediatrics, Univ. Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands.
authors.forename: Esther M E
authors.initials: EM
authors.lastname: van Straten
authors.forename: Vincent W
authors.initials: VW
authors.lastname: Bloks
authors.forename: Nicolette C A
authors.initials: NC
authors.lastname: Huijkman
authors.forename: Julius F W
authors.initials: JF
authors.lastname: Baller
authors.forename: Hester
authors.initials: H
authors.lastname: van Meer
authors.forename: Dieter
authors.initials: D
authors.lastname: Lütjohann
authors.forename: Folkert
authors.initials: F
authors.lastname: Kuipers
authors.forename: Torsten
authors.initials: T
authors.lastname: Plösch
mesh_terms: D000818:Animals; D001483:Base Sequence; D001724:Birth Weight / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D019556:COS Cells; D002522:Chlorocebus aethiops; D018899:CpG Islands / Q000235:genetics; D003562:Cytidine / Q000031:analogs & derivatives / Q000494:pharmacology; D019175:DNA Methylation / Q000187:drug effects*; D004032:Diet; D044127:Epigenesis, Genetic; D005260:Female; D050356:Lipid Metabolism / Q000235:genetics / Q000502:physiology; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D000071518:Liver X Receptors; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis; D057093:Orphan Nuclear Receptors / Q000235:genetics*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000235:genetics* / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011502:Protein-Energy Malnutrition / Q000235:genetics* / Q000378:metabolism*
chemical_list: D000071518:Liver X Receptors; C000605214:Nr1h3 protein, mouse; D057093:Orphan Nuclear Receptors; D003562:Cytidine; C009131:pyrimidin-2-one beta-ribofuranoside