title: The effect of lubricin on the gliding resistance of mouse intrasynovial tendon.
abstract: The purpose of this study was to investigate the role of lubricin on the gliding resistance of intrasynovial tendons by comparing lubricin knockout, heterozygous, and wild type mice. A total of thirty-six deep digital flexor (DDF) tendons in the third digits of each hind paw from eighteen adult mice were used, including six lubricin knockout mice (Prg4 -/-), six heterozygous mice (Prg4 +/-), and six wild type mice (Prg4 +/+). The tendon gliding resistance was measured using a custom-made device. Tendon structural changes were evaluated by scanning electron and light microscopy. The gliding resistance of intrasynovial tendons from lubricin knockout mice was significantly higher than the gliding resistance of either wild type or heterozygous mice. The surface of the lubricin knockout tendons appeared to be rougher, compared to the wild type and heterozygous tendons. Synovial hyperplasia was found in the lubricin knockout mice. Cartilage-like tissue was found in the tendon and pulley of the lubricin knockout mice. Our findings confirm the importance of lubricin in intrasynovial tendon lubrication. This knockout model may be useful in determining the effect of lubricin on tendon healing and the response to injury.
authors.affiliation: Biomechanics Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, Minnesota, United States of America.
authors.forename: Masanori
authors.initials: M
authors.lastname: Hayashi
authors.affiliation: Biomechanics Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, Minnesota, United States of America.
authors.forename: Chunfeng
authors.initials: C
authors.lastname: Zhao
authors.affiliation: Biomechanics Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, Minnesota, United States of America.
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Thoreson
authors.affiliation: Biomechanics Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, Minnesota, United States of America.
authors.forename: Takako
authors.initials: T
authors.lastname: Chikenji
authors.affiliation: Department of Emergency Medicine, Rhode Island Hospital and Brown University, ‪‬‬‬‬‪Providence, Rhode Island, United States of America.
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Jay
authors.affiliation: Biomechanics Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, Minnesota, United States of America.
authors.forename: Kai-Nan
authors.initials: KN
authors.lastname: An
authors.affiliation: Biomechanics Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, Minnesota, United States of America.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Amadio
mesh_terms: D000818:Animals; D017276:Friction; D006965:Hyperplasia; D051379:Mice; D018345:Mice, Knockout; D011509:Proteoglycans / Q000235:genetics / Q000378:metabolism*; D013583:Synovial Membrane / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology*; D013708:Tendon Injuries / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D013710:Tendons / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology*; D000099158:Proteoglycan 4
chemical_list: D011509:Proteoglycans; C498837:Prg4 protein, mouse; D000099158:Proteoglycan 4