title: Increased expression of transforming growth factor-beta1 in patellar tendinosis.
abstract: Patellar tendinosis is characterized by longstanding localized and activity-related pain, swelling and tenderness on palpation, and characteristic features on magnetic resonance imaging and ultrasonography and during surgical excision. Histologic examination of tendinosis tissues shows disrupted collagen matrix, increased cellularity, and increased proteoglycan stainability, but lack of inflammatory cell infiltration despite the clinical signs resembling inflammation. Disturbances in inflammatory response may be associated with the development of tendinosis. Expression of cyclooxygenase-2 and transforming growth factor-beta1 were detected in tendinosis, and the in vitro production of prostaglandin E2 by tendinosis and healthy tendon fibroblast cultures also was observed. Eleven patients with patellar tendinosis and 12 control subjects with healthy patellar tendons, but deficient anterior cruciate ligaments, were included in the current study. The percentages of immunopositive cells in tendinosis samples for cyclooxygenase-2 and transforming growth factor-beta1 were 66.75 and 56.40, respectively, which were significantly higher than those of the control subjects (25.15 and 23.06 respectively). Tendinosis fibroblast culture also produced more prostaglandin E2 and active transforming growth factor-beta1. These findings indicate the involvement of prostaglandins and cytokines that may explain the clinical symptoms and nonhealing features of tendinosis.
authors.affiliation: Department of Orthopaedics & Traumatology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong, ROC.
authors.forename: Sai Chuen
authors.initials: SC
authors.lastname: Fu
authors.forename: Wen
authors.initials: W
authors.lastname: Wang
authors.forename: Hon Man
authors.initials: HM
authors.lastname: Pau
authors.forename: Yim Ping
authors.initials: YP
authors.lastname: Wong
authors.forename: Kai Ming
authors.initials: KM
authors.lastname: Chan
authors.forename: Christer Gustav
authors.initials: CG
authors.lastname: Rolf
mesh_terms: D000293:Adolescent; D000328:Adult; D015232:Dinoprostone / Q000378:metabolism; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D007719:Knee Joint / Q000378:metabolism*; D008297:Male; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D052256:Tendinopathy / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000378:metabolism*; D053773:Transforming Growth Factor beta1
chemical_list: C508960:TGFB1 protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D011451:Prostaglandin-Endoperoxide Synthases; D015232:Dinoprostone