title: Increased systemic and local interleukin 9 levels in patients with carotid and coronary atherosclerosis.
abstract: OBJECTIVE
  Atherosclerosis is a chronic inflammatory disorder that involves a range of inflammatory mediators. Although interleukin (IL)-9 has been related to inflammation, there are at present no data on its role in atherosclerosis. Here we have examined IL-9 and IL-9 receptor (IL-9R) systemically and locally in patients with coronary and carotid atherosclerosis.
  
  
  METHODS
  Plasma IL-9 was quantified by enzyme immunoassay and multiplex technology. IL-9 and IL-9R mRNA were quantified by real-time RT-PCR, and their localization within the lesion was assessed by immunohistochemistry.
  
  
  RESULTS
  THE MAIN FINDINGS WERE: (i) Patients with carotid atherosclerosis had significantly raised IL-9 plasma levels compared with healthy controls (n = 28), with no differences between asymptomatic (n = 56) and symptomatic (n = 88) patients. (ii) On admission, patients with acute ST-elevation myocardial infarction (STEMI) (n = 42) had markedly raised IL-9 plasma levels which gradually declined during the first week post-MI. (iii) T cells and monocytes from patients with unstable angina (n = 17) had increased mRNA levels of IL-9 as compared with controls (n = 11). (iv) Carotid plaques (n = 68) showed increased mRNA levels of IL-9 and IL-9R compared to non-atherosclerotic vessels (n = 10). Co-localization to T cells (IL-9 and IL-9R) and macrophages (IL-9) were shown by immunohistochemistry. (v) IL-9 increased IL-17 release in peripheral blood mononuclear cells from patients with unstable angina (n = 5) and healthy controls (n = 5) with a particularly enhancing effect in cells from the patient group.
  
  
  CONCLUSIONS
  Our findings show increased IL-9 levels in different atherosclerotic disorders both systemically and within the lesion, suggesting a role for the IL-9/IL-9R axis in the atherosclerotic process, potentially involving IL-17 mediated mechanisms. However, the functional consequences of these findings should be further investigated.
authors.affiliation: Research Institute of Internal Medicine, Oslo University Hospital Rikshospitalet, Oslo, Norway ; Faculty of Medicine, University of Oslo, Oslo, Norway.
authors.forename: Ida
authors.initials: I
authors.lastname: Gregersen
authors.forename: Mona
authors.initials: M
authors.lastname: Skjelland
authors.forename: Sverre
authors.initials: S
authors.lastname: Holm
authors.forename: Kirsten B
authors.initials: KB
authors.lastname: Holven
authors.forename: Kirsten
authors.initials: K
authors.lastname: Krogh-Sørensen
authors.forename: David
authors.initials: D
authors.lastname: Russell
authors.forename: Erik T
authors.initials: ET
authors.lastname: Askevold
authors.forename: Christen P
authors.initials: CP
authors.lastname: Dahl
authors.forename: Stein
authors.initials: S
authors.lastname: Ørn
authors.forename: Lars
authors.initials: L
authors.lastname: Gullestad
authors.forename: Tom E
authors.initials: TE
authors.lastname: Mollnes
authors.forename: Thor
authors.initials: T
authors.lastname: Ueland
authors.forename: Pål
authors.initials: P
authors.lastname: Aukrust
authors.forename: Bente
authors.initials: B
authors.lastname: Halvorsen
mesh_terms: D017252:CD3 Complex / Q000378:metabolism; D002340:Carotid Artery Diseases / Q000097:blood*; D016893:Carotid Stenosis / Q000378:metabolism / Q000473:pathology; D003324:Coronary Artery Disease / Q000097:blood*; D005260:Female; D006801:Humans; D020381:Interleukin-17 / Q000378:metabolism; D016906:Interleukin-9 / Q000097:blood*; D018950:Lipopolysaccharide Receptors / Q000378:metabolism; D008297:Male; D009000:Monocytes / Q000378:metabolism; D053651:Receptors, Interleukin-9 / Q000378:metabolism
chemical_list: D017252:CD3 Complex; C508607:IL9 protein, human; D020381:Interleukin-17; D016906:Interleukin-9; D018950:Lipopolysaccharide Receptors; D053651:Receptors, Interleukin-9
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