title: Vascular endothelial growth factor plays an important autocrine/paracrine role in the progression of osteoarthritis.
abstract: Vascular endothelial growth factor (VEGF) plays an essential role in the angiogenesis of growing cartilage. Although VEGF expression in cartilage vanishes in normal adults, VEGF is known to be expressed in chondrocytes of osteoarthritic (OA) cartilage. As little information is available on the VEGF expression in the cartilage of OA-like lesions of the temporomandibular joint (TMJ), VEGF expression in the condylar cartilage of TMJs of rats affected with OA was examined. To evoke OA, mechanical stress was applied by forced jaw opening for 10 or 20 days. After 20 days, marked OA-like lesions were observed in the condyle. VEGF was expressed in the chondrocytes of the mature and hypertrophic cell layers of the intermediate and posterior region of the condyle. The percentage of VEGF immunopositive chondrocytes significantly increased with the period of applied mechanical stress. Furthermore, tartrate-resistant acid phosphatase (TRAP) staining of the condylar cartilage showed significant increment of osteoclasts in the mineralized layer subjacent to the hypertrophic layer where high VEGF expression could be detected. The results suggest that VEGF plays an important role in the progression of OA.
authors.affiliation: Department of Orthodontics and Craniofacial Developmental Biology, Hiroshima University Graduate School of Biomedical Sciences, Minami-ku, 734-8553 Hiroshima, Japan. etanaka@hiroshima-u.ac.jp
authors.forename: Eiji
authors.initials: E
authors.lastname: Tanaka
authors.forename: Junko
authors.initials: J
authors.lastname: Aoyama
authors.forename: Mutsumi
authors.initials: M
authors.lastname: Miyauchi
authors.forename: Takashi
authors.initials: T
authors.lastname: Takata
authors.forename: Koichi
authors.initials: K
authors.lastname: Hanaoka
authors.forename: Tatsunori
authors.initials: T
authors.lastname: Iwabe
authors.forename: Kazuo
authors.initials: K
authors.lastname: Tanne
mesh_terms: D000135:Acid Phosphatase / Q000032:analysis; D000818:Animals; D019898:Autocrine Communication; D019902:Chondrocytes / Q000737:chemistry / Q000378:metabolism; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000032:analysis; D008297:Male; D010003:Osteoarthritis / Q000378:metabolism* / Q000473:pathology; D010010:Osteoclasts / Q000737:chemistry / Q000378:metabolism; D019899:Paracrine Communication; D051381:Rats; D017208:Rats, Wistar; D013194:Staining and Labeling; D000071681:Tartrate-Resistant Acid Phosphatase; D013704:Temporomandibular Joint / Q000378:metabolism* / Q000473:pathology; D042442:Vascular Endothelial Growth Factors / Q000032:analysis / Q000096:biosynthesis / Q000378:metabolism*
chemical_list: D007527:Isoenzymes; D042442:Vascular Endothelial Growth Factors; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase