title: Expression of transforming growth factor beta isoforms and their roles in tendon healing.
abstract: Transforming growth factor beta (TGF-beta) plays active roles in tendon healing. However, the differential effects of TGF-beta isoforms on tendon healing have not been investigated. In cultured tendon fibroblasts, we tested the effects of TGF-beta1, beta2, and beta3 on the mRNA levels of COL1A1 and COL3A1 by quantitative real-time polymerase chain reaction. We also investigated the expression of TGF-beta isoforms, TGF-beta receptors, procollagen Type I and Type III in a rat model of tendon healing. We found that TGF-beta3 exhibited the highest potency in stimulating COL1A1 and COL3A1. TGF-beta1 exerted antagonistic effects to TGF-beta2 and beta3. All TGF-beta isoforms and procollagen Type I were confined to the edges of the healing tendon at day 28 postinjury. Our results indicated that interaction of TGF-beta isoforms exist in the regulation of collagen synthesis in tendon fibroblasts. Their effects may be further complicated by uneven spatial distribution of TGF-beta and TGF-beta receptors in healing tendons.
authors.affiliation: Department of Orthopaedics & Traumatology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong. kaimingchan@cuhk.edu.hk
authors.forename: Kai-Ming
authors.initials: KM
authors.lastname: Chan
authors.forename: Sai-Chuen
authors.initials: SC
authors.lastname: Fu
authors.forename: Yim-Ping
authors.initials: YP
authors.lastname: Wong
authors.forename: Wun-Chun
authors.initials: WC
authors.lastname: Hui
authors.forename: Yau-Chuk
authors.initials: YC
authors.lastname: Cheuk
authors.forename: Margaret Wan-Nar
authors.initials: MW
authors.lastname: Wong
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D024042:Collagen Type I / Q000235:genetics*; D000090602:Collagen Type I, alpha 1 Chain; D024061:Collagen Type III / Q000235:genetics*; D004195:Disease Models, Animal; D015870:Gene Expression; D016133:Polymerase Chain Reaction; D020033:Protein Isoforms / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D018125:Receptors, Transforming Growth Factor beta / Q000378:metabolism; D013708:Tendon Injuries / Q000503:physiopathology*; D014018:Tissue Distribution; D016212:Transforming Growth Factor beta / Q000378:metabolism*; D014945:Wound Healing / Q000502:physiology*
chemical_list: D024042:Collagen Type I; D000090602:Collagen Type I, alpha 1 Chain; D024061:Collagen Type III; D020033:Protein Isoforms; D012333:RNA, Messenger; D018125:Receptors, Transforming Growth Factor beta; D016212:Transforming Growth Factor beta