title: Altered gene and protein expression in liver of the obese spontaneously hypertensive/NDmcr-cp rat.
abstract: BACKGROUND
  It is difficult to study the mechanisms of the metabolic syndrome in humans due to the heterogeneous genetic background and lifestyle. The present study investigated changes in the gene and protein profiles in an animal model of the metabolic syndrome to identify the molecular targets associated with the pathogenesis and progression of obesity related to the metabolic syndrome.
  
  
  METHODS
  We extracted mRNAs and proteins from the liver tissues of 6- and 25-week-old spontaneously hypertensive/NIH -corpulent rat SHR/NDmcr-cp (CP), SHR/Lean (Lean) and Wistar Kyoto rats (WKY) and performed microarray analysis and two-dimensional difference in gel electrophoresis (2D-DIGE) linked to a matrix-assisted laser desorption ionization time-of-flight tandem mass spectrometry (MALDI-TOF/TOF MS).
  
  
  RESULTS
  The microarray analysis identified 25 significantly up-regulated genes (P < 0.01; log10 > 1) and 31 significantly down-regulated genes (P < 0.01; log10 < -1) in 6- and 25-week-old CP compared with WKY and Lean. Several of these genes are known to be involved in important biological processes such as electron transporter activity, electron transport, lipid metabolism, ion transport, transferase, and ion channel activity. MALDI-TOF/TOF MS identified 31 proteins with ±1.2 fold change (P < 0.05) in 6- and 25-week-old CP, compared with age-matched WKY and Lean. The up-regulated proteins are involved in metabolic processes, biological regulation, catalytic activity, and binding, while the down-regulated proteins are involved in endoplasmic reticulum stress-related unfolded protein response.
  
  
  CONCLUSIONS
  Genes with significant changes in their expression in transcriptomic analysis matched very few of the proteins identified in proteomics analysis. However, annotated functional classifications might provide an important reference resource to understand the pathogenesis of obesity associated with the metabolic syndrome.
authors.affiliation: Graduate School of Regional Innovation Studies, Mie University, 1577 Kurimamachiya-cho, Tsu 514-8507, Japan. saho@gene.mie-u.ac.jp.
authors.forename: Jie
authors.initials: J
authors.lastname: Chang
authors.forename: Shinji
authors.initials: S
authors.lastname: Oikawa
authors.forename: Gaku
authors.initials: G
authors.lastname: Ichihara
authors.forename: Yui
authors.initials: Y
authors.lastname: Nanpei
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Hotta
authors.forename: Yoshiji
authors.initials: Y
authors.lastname: Yamada
authors.forename: Saeko
authors.initials: S
authors.lastname: Tada-Oikawa
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Iwahashi
authors.forename: Emiko
authors.initials: E
authors.lastname: Kitagawa
authors.forename: Ichiro
authors.initials: I
authors.lastname: Takeuchi
authors.forename: Masao
authors.initials: M
authors.lastname: Yuda
authors.forename: Sahoko
authors.initials: S
authors.lastname: Ichihara