title: The distribution pattern of critically short telomeres in human osteoarthritic knees.
abstract: BACKGROUND
  Telomere shortening is associated with a number of common age-related diseases. A role of telomere shortening in osteoarthritis (OA) has been suggested, mainly based on the assessment of mean telomere length in ex vivo expanded chondrocytes. We addressed this role directly in vivo by using a newly developed assay, which measures specifically the load of ultra-short single telomeres (below 1,500 base pairs), that is, the telomere subpopulation believed to promote cellular senescence.
  
  
  METHODS
  Samples were obtained from human OA knees at two distances from the central lesion site. Each sample was split into three: one was used for quantification of ultra-short single telomeres through the Universal single telomere length assay (STELA), one for histological Mankin grading of OA, and one for mean telomere length measurement through quantitative fluorescence in situ hybridization (Q-FISH) as well as for assessment of senescence through quantification of senescence-associated heterochromatin foci (SAHF).
  
  
  RESULTS
  The load of ultra-short telomeres as well as mean telomere length was significantly associated with proximity to lesions, OA severity, and senescence level. The degree of significance was higher when assessed through load of ultra-short telomeres per cell compared with mean telomere length.
  
  
  CONCLUSIONS
  These in vivo data, especially the quantification of ultra-short telomeres, stress a role of telomere shortening in human OA.
authors.affiliation: Department of Clinical Cell Biology, Vejle/Lillebaelt Hospital, Institute of Regional Health Research, University of Southern Denmark, Kabbeltoft 25, 7100 Vejle, Denmark. maria.harbo@slb.regionsyddanmark.dk
authors.forename: Maria
authors.initials: M
authors.lastname: Harbo
authors.forename: Laila
authors.initials: L
authors.lastname: Bendix
authors.forename: Anne-Christine
authors.initials: AC
authors.lastname: Bay-Jensen
authors.forename: Jesper
authors.initials: J
authors.lastname: Graakjaer
authors.forename: Kent
authors.initials: K
authors.lastname: Søe
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Andersen
authors.forename: Per
authors.initials: P
authors.lastname: Kjaersgaard-Andersen
authors.forename: Steen
authors.initials: S
authors.lastname: Koelvraa
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Delaisse
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee; D016922:Cellular Senescence / Q000235:genetics; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007719:Knee Joint / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D012720:Severity of Illness Index; D016615:Telomere / Q000235:genetics*; D059506:Telomere Shortening