title: Tissue neogenesis and STRO-1 expression in immature and mature articular cartilage.
abstract: This study determined the potential for neotissue formation and the role of STRO-1+ cells in immature versus mature articular cartilage. Cartilage explants from immature and mature bovine knee joints were cultured for up to 12 weeks and stained with safranin-O, for type II collagen and STRO-1. Bovine chondrocyte pellet cultures and murine knee joints at the age of 2 weeks and 3 months, and surgically injured cartilage, were analyzed for changes in STRO-1 expression patterns. Results show that immature explants contained more STRO-1+ cells than mature explants. After 8 weeks in culture, immature explants showed STRO-1+ cell proliferation and newly formed tissue, which contained glycosaminoglycan and type II collagen. Mature cartilage explants showed only minimal cell expansion and neotissue formation. Pellet cultures with chondrocytes from immature cartilage showed increased glycosaminoglycan synthesis and STRO-1+ staining, as compared to pellets with mature chondrocytes. The frequency of STRO-1+ cells in murine knee joints significantly declined with joint maturation. Following surgical injury, immature explants had higher potential for tissue repair than mature explants. In conclusion, these findings suggest that the high percentage of STRO-1+ cells in immature cartilage changes with joint maturation. STRO-1+ cells have the potential to form new cartilage spontaneously and after tissue injury.
authors: Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
authors: Shuhei
authors: S
authors: Otsuki
authors: Shawn P
authors: SP
authors: Grogan
authors: Shigeru
authors: S
authors: Miyaki
authors: Mitsuo
authors: M
authors: Kinoshita
authors: Hiroshi
authors: H
authors: Asahara
authors: Martin K
authors: MK
authors: Lotz
mesh_terms: D000367:Age Factors; D000818:Animals; D000954:Antigens, Surface / Q000378:metabolism*; D002358:Cartilage, Articular / Q000254:growth & development / Q000293:injuries* / Q000378:metabolism* / Q000473:pathology; D002417:Cattle; D002478:Cells, Cultured; D019902:Chondrocytes / Q000378:metabolism; D024043:Collagen Type II / Q000378:metabolism; D006025:Glycosaminoglycans / Q000378:metabolism; D007718:Knee Injuries / Q000378:metabolism* / Q000473:pathology; D007719:Knee Joint / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D014945:Wound Healing / Q000502:physiology
chemical_list: D000954:Antigens, Surface; D024043:Collagen Type II; D006025:Glycosaminoglycans; C525590:STRO-1 antigen, mouse