title: Differential gene expression in the proximal neck of human abdominal aortic aneurysm.
abstract: OBJECTIVE
  Abdominal aortic aneurysm (AAA) represents a common cause of morbidity and mortality in elderly populations but the mechanisms involved in AAA formation remain incompletely understood. Previous human studies have focused on biopsies obtained from the center of the AAA however it is likely that pathological changes also occur in relatively normal appearing aorta away from the site of main dilatation. The aim of this study was to assess the gene expression profile of biopsies obtained from the neck of human AAAs.
  
  
  METHODS
  We performed a microarray study of aortic neck specimens obtained from 14 patients with AAA and 8 control aortic specimens obtained from organ donors. Two-fold differentially expressed genes were identified with correction for multiple testing. Mechanisms represented by differentially expressed genes were identified using Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Some of the differentially expressed genes were validated by quantitative real-time PCR (qPCR) and immunohistochemistry.
  
  
  RESULTS
  We identified 1047 differentially expressed genes in AAA necks. The KEGG analysis revealed marked upregulation of genes related to immunity. These pathways included cytokine-cytokine receptor interaction (P = 8.67*10(-12)), chemokine signaling pathway (P = 5.76*10(-07)), and antigen processing and presentation (P = 4.00*10(-04)). Examples of differentially expressed genes validated by qPCR included the T-cells marker CD44 (2.16-fold upregulated, P = 0.008) and the B-cells marker CD19 (3.14-fold upregulated, P = 0.029). The presence of B-cells in AAA necks was confirmed by immunohistochemistry.
  
  
  CONCLUSIONS
  The role of immunity in AAA is controversial. This study suggests that immune pathways are also upregulated within the undilated aorta proximal to an AAA.
authors: The Vascular Biology Unit, Queensland Research Centre for Peripheral Vascular Disease, School of Medicine, James Cook University, Townsville, Queensland, Australia.
authors: Erik
authors: E
authors: Biros
authors: The Vascular Biology Unit, Queensland Research Centre for Peripheral Vascular Disease, School of Medicine, James Cook University, Townsville, Queensland, Australia.
authors: Corey S
authors: CS
authors: Moran
authors: The Vascular Biology Unit, Queensland Research Centre for Peripheral Vascular Disease, School of Medicine, James Cook University, Townsville, Queensland, Australia; School of Veterinary and Biomedical Sciences, James Cook University, Townsville, Queensland, Australia.
authors: Catherine M
authors: CM
authors: Rush
authors: Department of Vascular and Endovascular Surgery, Ludwig Maximilians University Munich, Munich, Germany.
authors: Gabor
authors: G
authors: Gäbel
authors: Department of Vascular Surgery, Leiden University Medical Center, Leiden, The Netherlands.
authors: Charlotte
authors: C
authors: Schreurs
authors: Department of Vascular Surgery, Leiden University Medical Center, Leiden, The Netherlands.
authors: Jan H N
authors: JH
authors: Lindeman
authors: University of Queensland, School of Medicine, Discipline of Surgery, and Centre for Clinical Research and Royal Brisbane and Women's Hospital, Department of Vascular Surgery Herston, Queensland 4029, Australia.
authors: Philip J
authors: PJ
authors: Walker
authors: The Cardiovascular Research Group, Department of Medicine, the University of Queensland, Queensland, Australia.
authors: Maria
authors: M
authors: Nataatmadja
authors: The Cardiovascular Research Group, Department of Medicine, the University of Queensland, Queensland, Australia.
authors: Malcolm
authors: M
authors: West
authors: Institute of Laboratory Medicine, Ludwig Maximilians University Munich, Munich, Germany.
authors: Lesca M
authors: LM
authors: Holdt
authors: Department of General, Visceral, Vascular and Thoracic Surgery, Charité Universitätsmedizin Berlin, Charité Campus Mitte, Berlin, Germany.
authors: Irene
authors: I
authors: Hinterseher
authors: Department of Vascular and Endovascular Surgery, Ludwig Maximilians University Munich, Munich, Germany.
authors: Christian
authors: C
authors: Pilarsky
authors: The Vascular Biology Unit, Queensland Research Centre for Peripheral Vascular Disease, School of Medicine, James Cook University, Townsville, Queensland, Australia; Department of Vascular and Endovascular Surgery, The Townsville Hospital, Townsville, Queensland, Australia. Electronic address: jonathan.golledge@jcu.edu.au.
authors: Jonathan
authors: J
authors: Golledge
mesh_terms: D000328:Adult; D000368:Aged; D001012:Aorta, Abdominal / Q000378:metabolism* / Q000473:pathology; D017544:Aortic Aneurysm, Abdominal / Q000473:pathology / Q000503:physiopathology*; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D007109:Immunity / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D040081:Protein Array Analysis; D059467:Transcriptome / Q000502:physiology*; D015854:Up-Regulation
keywords: Abdominal; Aortic aneurysm; B-lymphocytes; Inflammation; Tissue array analysis