title: Sequential changes of parathyroid hormone related protein (PTHrP) in articular cartilage during progression of inflammatory and degenerative arthritis.
abstract: OBJECTIVE
  To investigate immunolocalisation of parathyroid hormone related protein (PTHrP) in two sequential models of experimental cartilage damage (inflammatory and degenerative) in order to elucidate differences in chondrocyte response to the disease.
  
  
  METHODS
  Immunohistochemistry with a polyclonal rabbit antiserum to the N-terminal domain of PTHrP was used to detect this protein in two different rabbit models sharing progressive cartilage damage: antigen induced arthritis (AIA) and osteoarthritis (OA) secondary to partial medial meniscectomy. Cartilage specimens from early (2 days in AIA; 8 weeks in experimental OA) and late (3 weeks in AIA; 52 weeks in OA) disease were compared.
  
  
  RESULTS
  Cell and matrix PTHrP staining in early AIA and OA was similar to that in controls. Late AIA cartilage showed a significant decrease in PTHrP positive cells and in the cartilage matrix. In contrast, at late OA stages, distinct PTHrP positivity was detected in proliferating cell clones, as assessed by proliferating cell nuclear antigen staining around cartilage damaged areas.
  
  
  CONCLUSIONS
  PTHrP staining of hyaline articular cartilage shows a different pattern during progression of each type of arthritis: an overall decrease associated with the inflammatory disease, and an increase in the proliferating chondrocyte clones with degenerative arthritis.
authors.affiliation: Servicio de Cirugía Ortopédica y Traumatología, Fundación Jiménez Díaz, Avda. Reyes Católicos 2, E-28040 Madrid, Spain. egomez@fjd.es
authors.forename: E
authors.initials: E
authors.lastname: Gómez-Barrena
authors.forename: O
authors.initials: O
authors.lastname: Sánchez-Pernaute
authors.forename: R
authors.initials: R
authors.lastname: Largo
authors.forename: E
authors.initials: E
authors.lastname: Calvo
authors.forename: P
authors.initials: P
authors.lastname: Esbrit
authors.forename: G
authors.initials: G
authors.lastname: Herrero-Beaumont
mesh_terms: D000818:Animals; D001169:Arthritis, Experimental / Q000378:metabolism* / Q000473:pathology; D002358:Cartilage, Articular / Q000378:metabolism* / Q000473:pathology; D004195:Disease Models, Animal; D018450:Disease Progression; D007124:Immunoenzyme Techniques; D008297:Male; D010003:Osteoarthritis / Q000378:metabolism / Q000473:pathology; D044162:Parathyroid Hormone-Related Protein / Q000378:metabolism*; D011817:Rabbits
chemical_list: D044162:Parathyroid Hormone-Related Protein