title: Evaluation of the association between runt-related transcription factor 2 expression and intervertebral disk aging in dogs.
abstract: OBJECTIVE
  To investigate the relationship between runt-related transcription factor 2 (RUNX2) expression in canine nucleus pulposus (NP) cells and intervertebral disk aging in chondrodystrophoid dogs.
  
  
  METHODS
  7 healthy Beagles (mean age, 35.6 months) and 11 Dachshunds with herniated disks (mean age, 61 months).
  
  
  METHODS
  All dogs underwent MRI examination of the thoracic and lumbar vertebral column immediately before sample collection under general anesthesia. The disk center-to-CSF T2-weighted signal intensity ratio was determined for healthy Beagles. Samples of NP were obtained from nonherniated disks in healthy Beagles and from herniated disks during surgical treatment of hospitalized Dachshunds. Samples were evaluated for RUNX2 and matrix metalloproteinase 13 transcript expression via reverse transcriptase PCR assay; RUNX2 protein expression was evaluated via immunohistochemical analysis, and correlation between these variables and age of dogs was evaluated. A 3' and 5' rapid amplification of cDNA ends method was used to identify the RUNX2 coding region.
  
  
  RESULTS
  RUNX2 cDNA had > 97% conservation with the human cDNA sequence and approximately 95% conservation with the mouse cDNA sequence; RUNX2 and matrix metalloproteinase 13 mRNA expression and RUNX2 protein expression in NP cells were positively correlated with age. The disk center-to-CSF T2-weighted signal intensity ratio was negatively correlated with RUNX2 protein expression in the NP of healthy dogs.
  
  
  CONCLUSIONS
  Results indicated that RUNX2 mRNA and protein expression in the NP are enhanced in aging intervertebral disks in dogs.
authors.affiliation: Division of Veterinary Surgery, Department of Veterinary Science, Faculty of Veterinary Medicine, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino, Tokyo, Japan.
authors.forename: Hisanori
authors.initials: H
authors.lastname: Itoh
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Hara
authors.forename: Masahiro
authors.initials: M
authors.lastname: Tagawa
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Kato
authors.forename: Hiroki
authors.initials: H
authors.lastname: Ochi
authors.forename: Daisuke
authors.initials: D
authors.lastname: Koga
authors.forename: Atsushi
authors.initials: A
authors.lastname: Okawa
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Asou
mesh_terms: D000375:Aging; D000818:Animals; D050659:Core Binding Factor Alpha 1 Subunit / Q000235:genetics / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D004283:Dog Diseases / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology*; D004285:Dogs / Q000033:anatomy & histology / Q000502:physiology*; D007150:Immunohistochemistry / Q000662:veterinary; D007403:Intervertebral Disc / Q000033:anatomy & histology* / Q000378:metabolism / Q000473:pathology*; D007405:Intervertebral Disc Displacement / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*; D008159:Lumbar Vertebrae / Q000378:metabolism / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000662:veterinary; D053509:Matrix Metalloproteinase 13 / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D017422:Sequence Analysis, DNA / Q000662:veterinary; D020539:Sequence Analysis, Protein / Q000662:veterinary; D013904:Thoracic Vertebrae / Q000378:metabolism / Q000473:pathology
chemical_list: D050659:Core Binding Factor Alpha 1 Subunit; D018076:DNA, Complementary; D012333:RNA, Messenger; D053509:Matrix Metalloproteinase 13