title: Scleraxis expression is coordinately regulated in a murine model of patellar tendon injury.
abstract: This study investigated the expression of Scleraxis in a murine model of patellar tendon injury in which the central third of the patellar tendon was unilaterally injured. The presence of tendon pathology was assessed using dual photon microscopy, conventional histology and microCT. Tendon pathology was also quantified noninvasively over a 12-week period using high-frequency ultrasound and laser Doppler flowmetry. Gene expression (Scx, Tnmd, and Col1a1) was determined at defined end-points (1, 4, 8, and 12 weeks) using qPCR on RNA from individual patellar tendons on injured and uninjured sides. There was significant development of tendon pathology as gauged by ultrasound and laser Doppler over 12 weeks. Injured tendons demonstrated significant histological and microCT evidence of pathological change, and disorganized collagen with reduced density. The expression of Scx and Col1a1 was unchanged at 1 week, significantly upregulated at 4 and 8 weeks, and had returned to baseline by 12 weeks. Tnmd expression was unchanged at 1 week, and significantly increased at 4, 8, and 12 weeks. Patellar tendon injury was associated with marked increases in the expression of Scx, Tnmd, and Col1a1. Our data suggest new roles for Scleraxis in coordinating the response to injury in the pathogenesis of tendon disorders.
authors.affiliation: Biomedical Research Centre, Vancouver, Canada. ascott@interchange.ubc.ca
authors.forename: Alexander
authors.initials: A
authors.lastname: Scott
authors.forename: Arthur
authors.initials: A
authors.lastname: Sampaio
authors.forename: Thomas
authors.initials: T
authors.lastname: Abraham
authors.forename: Chris
authors.initials: C
authors.lastname: Duronio
authors.forename: Tully M
authors.initials: TM
authors.lastname: Underhill
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism*; D003094:Collagen / Q000378:metabolism; D024042:Collagen Type I / Q000378:metabolism; D000090602:Collagen Type I, alpha 1 Chain; D005260:Female; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D017847:Patellar Ligament / Q000098:blood supply / Q000293:injuries* / Q000473:pathology; D012039:Regional Blood Flow; D013708:Tendon Injuries / Q000175:diagnosis / Q000378:metabolism*; D014945:Wound Healing; D055114:X-Ray Microtomography
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D003094:Collagen; D024042:Collagen Type I; D000090602:Collagen Type I, alpha 1 Chain; D008565:Membrane Proteins; C503815:Scx protein, mouse; C486026:Tnmd protein, mouse