title: Glucocorticoid receptor is involved in the breed-dependent transcriptional regulation of mtDNA- and nuclear-encoded mitochondria genes in the liver of newborn piglets.
abstract: BACKGROUND
  Mitochondria, which are essential for the functionality of eukaryotic cells, are particularly important in metabolically active tissues such as liver. Different breeds of pigs demonstrate distinct metabolic profiles in the liver, yet little is known whether the expression and transcriptional regulation of mitochondrial genes differ between breeds.
  
  
  RESULTS
  Here we used male newborn Large White (LW) and Erhualian (EHL) piglets to delineate the difference in hepatic mitochondrial gene regulation between breeds. The hepatic content of ATP was significantly higher (p < 0.01) in EHL piglets, which was associated with lower mtDNA copy number (p < 0.05). Most of the mtDNA-encoded genes (10 of 13), however, were more abundantly expressed in EHL compared to LW piglets. We also detected 3 differentially expressed nuclear-encoded mitochondrial genes, among which isocitrate dehydrogenase 2 (IDH2) and ATP synthase, H+ transporting, mitochondrial Fo complex, subunit d (ATP5H) were expressed significantly lower, while adenylate kinase 1 (AK1) was significantly over expressed in EHL piglets. Compared to LW, the over expression of mtDNA-encoded genes in EHL was associated with significantly higher (p < 0.01) glucocorticoid receptor (GR) binding to the control region of mtDNA with no alterations in the methylation status. For nuclear-encoded genes, however, a negative correlation was observed between GR binding and mRNA expression of AK1 and ATP5H. Moreover, higher expression of AK1 in EHL piglets was also associated with lower cytosine methylation (p < 0.05) and hydroxymethylation (p < 0.05). In the promoter region.
  
  
  CONCLUSIONS
  These results indicate a role of the GR in the breed-dependent regulation of mitochondrial genes in the liver of newborn piglets.
authors.affiliation: Key Laboratory of Animal Physiology & Biochemistry, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu, China. zhao.ruqian@gmail.com
authors.forename: Runsheng
authors.initials: R
authors.lastname: Li
authors.forename: Huafeng
authors.initials: H
authors.lastname: Zou
authors.forename: Yimin
authors.initials: Y
authors.lastname: Jia
authors.forename: Ruqian
authors.initials: R
authors.lastname: Zhao
mesh_terms: D000255:Adenosine Triphosphate / Q000032:analysis; D000263:Adenylate Kinase / Q000096:biosynthesis / Q000235:genetics; D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism; D002467:Cell Nucleus / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics*; D005786:Gene Expression Regulation / Q000187:drug effects* / Q000502:physiology; D007521:Isocitrate Dehydrogenase / Q000096:biosynthesis / Q000235:genetics; D008099:Liver / Q000737:chemistry / Q000378:metabolism*; D008297:Male; D008930:Mitochondria, Liver / Q000235:genetics*; D025261:Mitochondrial Proton-Translocating ATPases / Q000096:biosynthesis / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D011965:Receptors, Glucocorticoid / Q000502:physiology*; D013045:Species Specificity; D013552:Swine; D014158:Transcription, Genetic / Q000235:genetics / Q000502:physiology
chemical_list: D004272:DNA, Mitochondrial; D011965:Receptors, Glucocorticoid; D000255:Adenosine Triphosphate; D007521:Isocitrate Dehydrogenase; D000263:Adenylate Kinase; C110939:adenylate kinase 1; D025261:Mitochondrial Proton-Translocating ATPases