title: Association between leukocyte telomere length and angiogenic cytokines in knee osteoarthritis.
abstract: OBJECTIVE
  The aims of this study were to compare leukocyte relative telomere length (RTL) in knee osteoarthritis (OA) patients and healthy controls and to investigate associations between plasma angiogenic cytokine concentrations and leukocyte RTL.
  
  
  METHODS
  Eighty knee OA patients and 60 age-matched controls were enrolled. Leukocyte RTL was assessed using real-time quantitative polymerase chain reaction (qPCR). Angiogenic cytokines were measured by a multiplex immunoassay.
  
  
  RESULTS
  Leukocyte RTL in knee OA patients was significantly lower than that in healthy controls (1.1 ± 0.4 vs. 1.3 ± 0.6, P = 0.039). Plasma angiopoietin-2, follistatin, granulocyte-colony stimulating factor (G-CSF), hepatocyte growth factor (HGF), interleukin-8 (IL-8), platelet endothelial cell adhesion molecule-1 (PECAM-1), and vascular endothelial growth factor (VEGF) levels in knee OA patients were higher than those in controls (P < 0.01). Correlation analysis revealed significant negative correlations between leukocyte RTL and plasma levels of HGF (r = -0.377, P = 0.017), VEGF (r = -0.405, P = 0.009) and G-CSF (r = -0.347, P = 0.026). In contrast, plasma angiopoietin-2, follistatin, IL-8, leptin, platelet-derived growth factor-BB and PECAM-1 were not correlated with leukocyte RTL.
  
  
  CONCLUSIONS
  Telomere length was shortened in knee OA patients compared to healthy controls. Plasma HGF, VEGF and G-CSF were negatively correlated with leukocyte RTL, suggesting involvement of telomere shortening and these cytokines in knee OA.
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
authors.forename: Thitiya
authors.initials: T
authors.lastname: Poonpet
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
authors.forename: Natthaphon
authors.initials: N
authors.lastname: Saetan
authors.affiliation: Department of Orthopaedics, Faculty of Medicine, Vinai Parkpian Orthopaedic Research Center, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Chulalongkorn University, Bangkok, Thailand.
authors.forename: Aree
authors.initials: A
authors.lastname: Tanavalee
authors.affiliation: Department of Orthopaedics, Faculty of Medicine, Vinai Parkpian Orthopaedic Research Center, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Chulalongkorn University, Bangkok, Thailand.
authors.forename: Vajara
authors.initials: V
authors.lastname: Wilairatana
authors.affiliation: Department of Orthopaedics, Faculty of Medicine, Vinai Parkpian Orthopaedic Research Center, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Chulalongkorn University, Bangkok, Thailand.
authors.forename: Pongsak
authors.initials: P
authors.lastname: Yuktanandana
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.|Department of Orthopaedics, Faculty of Medicine, Vinai Parkpian Orthopaedic Research Center, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Chulalongkorn University, Bangkok, Thailand.
authors.forename: Sittisak
authors.initials: S
authors.lastname: Honsawek
mesh_terms: D000368:Aged; D042501:Angiogenic Proteins / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D016207:Cytokines / Q000097:blood*; D005260:Female; D016179:Granulocyte Colony-Stimulating Factor / Q000097:blood; D017228:Hepatocyte Growth Factor / Q000097:blood; D006801:Humans; D007118:Immunoassay; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000097:blood* / Q000175:diagnosis / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D016615:Telomere / Q000235:genetics / Q000378:metabolism*; D059506:Telomere Shortening; D042461:Vascular Endothelial Growth Factor A / Q000097:blood
chemical_list: D042501:Angiogenic Proteins; D015415:Biomarkers; D016207:Cytokines; C066855:HGF protein, human; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D016179:Granulocyte Colony-Stimulating Factor; D017228:Hepatocyte Growth Factor
keywords: angiogenesis; cytokines; osteoarthritis; real-time quantitative PCR; telomere length