title: The role of bone sialoprotein in the tendon-bone insertion.
abstract: Tendons/ligaments insert into bone via a transitional structure, the enthesis, which is susceptible to injury and difficult to repair. Fibrocartilaginous entheses contain fibrocartilage in their transitional zone, part of which is mineralized. Mineral-associated proteins within this zone have not been adequately characterized. Members of the Small Integrin Binding Ligand N-linked Glycoprotein (SIBLING) family are acidic phosphoproteins expressed in mineralized tissues. Here we show that two SIBLING proteins, bone sialoprotein (BSP) and osteopontin (OPN), are present in the mouse enthesis. Histological analyses indicate that the calcified zone of the quadriceps tendon enthesis is longer in Bsp(-/-) mice, however no difference is apparent in the supraspinatus tendon enthesis. In an analysis of mineral content within the calcified zone, micro-CT and Raman spectroscopy reveal that the mineral content in the calcified fibrocartilage of the quadriceps tendon enthesis are similar between wild type and Bsp(-/-) mice. Mechanical testing of the patellar tendon shows that while the tendons fail under similar loads, the Bsp(-/-) patellar tendon is 7.5% larger in cross sectional area than wild type tendons, resulting in a 16.5% reduction in failure stress. However, Picrosirius Red staining shows no difference in collagen organization. Data collected here indicate that BSP is present in the calcified fibrocartilage of murine entheses and suggest that BSP plays a regulatory role in this structure, influencing the growth of the calcified fibrocartilage in addition to the weakening of the tendon mechanical properties. Based on the phenotype of the Bsp(-/-) mouse enthesis, and the known in vitro functional properties of the protein, BSP may be a useful therapeutic molecule in the reattachment of tendons and ligaments to bone.
authors.affiliation: Department of Biochemistry, University of Western Ontario, London, ON, Canada.
authors.forename: Ryan
authors.initials: R
authors.lastname: Marinovich
authors.affiliation: Biomedical Engineering Program, University of Western Ontario, London, ON, Canada.
authors.forename: Yohannes
authors.initials: Y
authors.lastname: Soenjaya
authors.affiliation: Department of Chemistry, University of Western Ontario, London, ON, Canada.
authors.forename: Gregory Q
authors.initials: GQ
authors.lastname: Wallace
authors.affiliation: McKay Orthopaedic Research Laboratory, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Andre
authors.initials: A
authors.lastname: Zuskov
authors.affiliation: McKay Orthopaedic Research Laboratory, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Dunkman
authors.affiliation: Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA.
authors.forename: Brian L
authors.initials: BL
authors.lastname: Foster
authors.affiliation: National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA.
authors.forename: Min
authors.initials: M
authors.lastname: Ao
authors.affiliation: Department of Biochemistry, University of Western Ontario, London, ON, Canada.
authors.forename: Kevin
authors.initials: K
authors.lastname: Bartman
authors.affiliation: School of Dentistry, University of Western Ontario, London, ON, Canada.
authors.forename: Vida
authors.initials: V
authors.lastname: Lam
authors.affiliation: Biomedical Engineering Program, University of Western Ontario, London, ON, Canada; School of Dentistry, University of Western Ontario, London, ON, Canada.
authors.forename: Amin
authors.initials: A
authors.lastname: Rizkalla
authors.affiliation: Department of Physiology and Pharmacology, University of Western Ontario, London, ON, Canada.
authors.forename: Frank
authors.initials: F
authors.lastname: Beier
authors.affiliation: National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA.
authors.forename: Martha J
authors.initials: MJ
authors.lastname: Somerman
authors.affiliation: Departments of Surgery and Medical Biophysics, University of Western Ontario, London, ON, Canada.
authors.forename: David W
authors.initials: DW
authors.lastname: Holdsworth
authors.affiliation: McKay Orthopaedic Research Laboratory, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Louis J
authors.initials: LJ
authors.lastname: Soslowsky
authors.affiliation: Department of Chemistry, University of Western Ontario, London, ON, Canada.
authors.forename: François
authors.initials: F
authors.lastname: Lagugné-Labarthet
authors.affiliation: Department of Biochemistry, University of Western Ontario, London, ON, Canada; School of Dentistry, University of Western Ontario, London, ON, Canada. Electronic address: hagoldbe@uwo.ca.
authors.forename: Harvey A
authors.initials: HA
authors.lastname: Goldberg
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000378:metabolism / Q000648:ultrastructure*; D002113:Calcification, Physiologic; D058574:Integrin-Binding Sialoprotein / Q000378:metabolism*; D051379:Mice; D053495:Osteopontin / Q000378:metabolism*; D013059:Spectrum Analysis, Raman; D013710:Tendons / Q000378:metabolism / Q000648:ultrastructure*; D055114:X-Ray Microtomography
chemical_list: C546872:Ibsp protein, mouse; D058574:Integrin-Binding Sialoprotein; C506896:Spp1 protein, mouse; D053495:Osteopontin
keywords: Bone sialoprotein; Calcified fibrocartilage; Enthesis; Osteopontin; Quadriceps tendon; Supraspinatus tendon
references.citation: Matrix Biol. 1998 Mar;16(8):457-70
references.pmid: 9550263
references.citation: J Biol Chem. 2005 Apr 8;280(14):13487-92
references.pmid: 15703183
references.citation: Bone. 2015 Feb;71:145-54
references.pmid: 25464126
references.citation: J Anat. 1998 Nov;193 ( Pt 4):481-94
references.pmid: 10029181
references.citation: J Dent Res. 2013 Feb;92(2):166-72
references.pmid: 23183644
references.citation: Bone. 2010 Feb;46(2):447-52
references.pmid: 19761880
references.citation: Matrix Biol. 2013 Mar 11;32(2):106-16
references.pmid: 23357642
references.citation: J Dent Res. 2015 Sep;94(9):1276-85
references.pmid: 26130257
references.citation: J Exp Med. 2008 May 12;205(5):1145-53
references.pmid: 18458111
references.citation: Matrix Biol. 2013 Jan;32(1):3-13
references.pmid: 23178232
references.citation: J Bone Joint Surg Am. 2004 Feb;86-A(2):219-24
references.pmid: 14960664
references.citation: Dev Biol. 2007 Jun 15;306(2):612-23
references.pmid: 17467682
references.citation: Calcif Tissue Int. 2006 Sep;79(3):179-89
references.pmid: 16969594
references.citation: PLoS One. 2013;8(6):e65411
references.pmid: 23762363
references.citation: Calcif Tissue Int. 2009 Sep;85(3):235-46
references.pmid: 19609735
references.citation: J Anat. 2001 Nov;199(Pt 5):503-26
references.pmid: 11760883
references.citation: Bone. 2012 May;50(5):1064-73
references.pmid: 22586700
references.citation: Proc Natl Acad Sci U S A. 1993 Sep 15;90(18):8562-5
references.pmid: 8397409
references.citation: J Biol Chem. 2003 Mar 7;278(10):7949-55
references.pmid: 12493752
references.citation: Development. 2015 Jan 1;142(1):196-206
references.pmid: 25516975
references.citation: PLoS One. 2014;9(5):e95144
references.pmid: 24816232
references.citation: Stain Technol. 1972 May;47(3):129-36
references.pmid: 4111887
references.citation: Nat Genet. 2006 Nov;38(11):1248-50
references.pmid: 17033625
references.citation: J Orthop Res. 2007 Sep;25(9):1154-63
references.pmid: 17506506
references.citation: Matrix Biol. 2008 Sep;27(7):600-8
references.pmid: 18620053
references.citation: Bone. 2007 Sep;41(3):462-73
references.pmid: 17572166
references.citation: Birth Defects Res C Embryo Today. 2014 Mar;102(1):101-12
references.pmid: 24677726
references.citation: J Biomech Eng. 2003 Feb;125(1):106-13
references.pmid: 12661203
references.citation: Tissue Eng Part A. 2012 Mar;18(5-6):598-608
references.pmid: 21939397
references.citation: Anat Embryol (Berl). 1996 Oct;194(4):399-406
references.pmid: 8896704
references.citation: N Engl J Med. 1985 Jul 4;313(1):1-6
references.pmid: 4000222
references.citation: J Eng Mater Technol. 2011 Jan 1;133(1):null
references.pmid: 21743758
references.citation: Biochem J. 1994 Jun 15;300 ( Pt 3):723-8
references.pmid: 8010953
references.citation: Dev Biol. 2015 Sep 1;405(1):96-107
references.pmid: 26141957
references.citation: Bone. 2015 Sep;78:150-64
references.pmid: 25963390
references.citation: J Biomech. 2006;39(10):1842-51
references.pmid: 16024026
references.citation: J Anat. 1996 Apr;188 ( Pt 2):367-73
references.pmid: 8621336
references.citation: Bone. 2009 Nov;45(5):853-61
references.pmid: 19524706
references.citation: PLoS One. 2012;7(11):e48630
references.pmid: 23152788
references.citation: Matrix Biol. 2016 May-Jul;52-54:60-77
references.pmid: 26763578
references.citation: J Orthop Res. 2015 Aug;33(8):1142-51
references.pmid: 25807894
references.citation: Matrix Biol. 1998 Apr;17(1):65-73
references.pmid: 9628253
references.citation: Connect Tissue Res. 2003;44 Suppl 1:33-40
references.pmid: 12952171
references.citation: Biochem J. 2014 Dec 15;464(3):355-64
references.pmid: 25310312
references.citation: Biophys J. 2009 Aug 19;97(4):976-85
references.pmid: 19686644