title: Cpt1agene expression in peripheral blood mononuclear cells as an early biomarker of diet-related metabolic alterations.
abstract: BACKGROUND
  Research on biomarkers that provide early information about the development of future metabolic alterations is an emerging discipline. Gene expression analysis in peripheral blood mononuclear cells (PBMC) is a promising tool to identify subjects at risk of developing diet-related diseases.
  
  
  OBJECTIVE
  We analysed PBMC expression of key energy homeostasis-related genes in a time-course analysis in order to find out early markers of metabolic alterations due to sustained intake of high-fat (HF) and high-protein (HP) diets.
  
  
  METHODS
  We administered HF and HP diets (4 months) to adult Wistar rats in isocaloric conditions to a control diet, mainly to avoid overweight associated with the intake of hyperlipidic diets and, thus, to be able to characterise markers of metabolically obese normal-weight (MONW) syndrome. PBMC samples were collected at different time points of dietary treatment and expression of relevant energy homeostatic genes analysed by real-time reverse transcription-polymerase chain reaction. Serum parameters related with metabolic syndrome, as well as fat deposition in liver, were also analysed.
  
  
  RESULTS
  The most outstanding results were those obtained for the expression of the lipolytic gene carnitine palmitoyltransferase 1a (Cpt1a).Cpt1aexpression in PBMC increased after only 1 month of exposure to both unbalanced diets, and this increased expression was maintained thereafter. Interestingly, in the case of the HF diet,Cpt1aexpression was altered even in the absence of increased body weight but correlated with alterations such as higher insulin resistance, alteration of serum lipid profile and, particularly, increased fat deposition in liver, a feature characteristic of metabolic syndrome, which was even observed in animals fed with HP diet.
  
  
  CONCLUSIONS
  We proposeCpt1agene expression analysis in PBMC as an early biomarker of metabolic alterations associated with MONW phenotype due to the intake of isocaloric HF diets, as well as a marker of increased risk of metabolic diseases associated with the intake of HF or HP diets.
authors.affiliation: Laboratory of Molecular Biology, Nutrition and Biotechnology, Universitat de les Illes Balears and CIBER de Fisiopatología de la Obesidad y Nutrición (CIBERobn), Palma de Mallorca, Spain.
authors.forename: Rubén
authors.initials: R
authors.lastname: Díaz-Rúa
authors.affiliation: Laboratory of Molecular Biology, Nutrition and Biotechnology, Universitat de les Illes Balears and CIBER de Fisiopatología de la Obesidad y Nutrición (CIBERobn), Palma de Mallorca, Spain; andreu.palou@uib.es.
authors.forename: Andreu
authors.initials: A
authors.lastname: Palou
authors.affiliation: Laboratory of Molecular Biology, Nutrition and Biotechnology, Universitat de les Illes Balears and CIBER de Fisiopatología de la Obesidad y Nutrición (CIBERobn), Palma de Mallorca, Spain.
authors.forename: Paula
authors.initials: P
authors.lastname: Oliver
keywords: PBMC; dietary markers; high-fat diet; high-protein diet; liver steatosis; metabolic syndrome; prevention markers; unbalanced diets