title: Age-dependent changes in the mechanical properties of tail tendons in TGF-beta inducible early gene-1 knockout mice.
abstract: The purpose of this study is to investigate age-dependent changes in the architecture and mechanical properties of tendon in TGF-beta inducible early gene-1 (TIEG) knockout mice. Wild-type and TIEG knockout mice, aged 1, 2, and 15 mo, were used. The mechanical properties of tail tendons isolated from these mice were determined using uniaxial tensile ramp (0.05 mm/s) and relaxation (5 mm/s) tests, with a strain of 10%. Mechanical parameters (Young's modulus from the ramp test; fast and static stresses from the relaxation test) were measured and recorded. The structure of the tail tendon fascicle was characterized by transmission electron microscopy. The results of the mechanical testing revealed no significant difference between the knockout and wild-type groups at 1 or 15 mo of age. However, the fascicles of the knockout mice at 3 mo of age exhibited decreased fast and static stresses compared with those of the wild-type mice. Electron microscopy revealed an increase in fibril size in the knockout mouse tendons relative to wild-type controls at 1 and 3 mo of age. These data indicate an important role for TIEG in tendon microarchitecture and strength in adult mice.
authors.affiliation: Biomechanics Laboratory, Department of Orthopedics, Mayo Clinic Rochester, Rochester, Minnesota 55905, USA.
authors.forename: Sabine F
authors.initials: SF
authors.lastname: Bensamoun
authors.forename: Tetsu
authors.initials: T
authors.lastname: Tsubone
authors.forename: Malayannan
authors.initials: M
authors.lastname: Subramaniam
authors.forename: John R
authors.initials: JR
authors.lastname: Hawse
authors.forename: Emir
authors.initials: E
authors.lastname: Boumediene
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Spelsberg
authors.forename: Kai-Nan
authors.initials: KN
authors.lastname: An
authors.forename: Peter C
authors.initials: PC
authors.lastname: Amadio
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D004268:DNA-Binding Proteins / Q000172:deficiency* / Q000235:genetics; D005260:Female; D051379:Mice; D018345:Mice, Knockout; D013314:Stress, Mechanical; D013623:Tail; D013710:Tendons / Q000502:physiology* / Q000648:ultrastructure*; D013718:Tensile Strength / Q000502:physiology; D014157:Transcription Factors / Q000172:deficiency* / Q000235:genetics; D016474:Weight-Bearing / Q000502:physiology; D051741:Kruppel-Like Transcription Factors; D051765:Early Growth Response Transcription Factors
chemical_list: D004268:DNA-Binding Proteins; D014157:Transcription Factors; C569958:KLF10 protein, mouse; D051741:Kruppel-Like Transcription Factors; D051765:Early Growth Response Transcription Factors