Functional Gap Junction Communication and Its Mechanobiological Role in the Outer Annulus Fibrosus

Decreased levels of intercellular communication with age or injury may play a role in the production of inappropriate matrix components leading to tissue degeneration. The gap junction protein connexin-43 has been shown to be present on the cell body and processes of annulus fibrosus cells (Gruber et al., 2001; Bruehlmann et al., 2002). Fluorescence recovery after photobleaching (FRAP) was used to assess cellular communication via gap junctions in the annulus fibrosus of six species. Functional gap junction communication was only observed in the bovine and porcine outer annulus. A preliminary study assessed changes in gene expression in response to load using an in vitro loading system that was modified for bovine outer annulus explants. Loading for 4 hours produced an increase in type I collagen expression and this response was eliminated by the presence of a gap junction blocker, 1-octanol. Loading did not appear to influence the expression of connexion-43, 18S rRNA, MMP-3 and aggrecan, although, 1-octanol appeared to decrease the expression of these genes.

Year	Entry
1999	Guilak F, Ting-Beall HP, Baer AE, Trickey WR, Erickson GR, Setton LA. Viscoelastic properties of intervertebral disc cells: identification of two biomechanically distinct cell populations. Spine. December 1, 1999;24(23):2475-2483.
1975	Maroudas A, Stockwell RA, Nachemson A, Urban J. Factors involved in the nutrition of the human lumbar intervertebral disc: cellularity and diffusion of glucose in vitro. J Anat. September 1975;120(1):113-130.
1987	Stokes IAF. Surface strain on human intervertebral discs. J Orthop Res. 1987;5(3):348-355.
2002	Rubin C, Turner AS, Mallinckrodt C, Jerome C, Mcleod K, Bain S. Mechanical strain, induced noninvasively in the high-frequency domain, is anabolic to cancellous bone, but not cortical bone. Bone. March 2002;30(3):445-452.
2005	Cherian PP, Siller-Jackson AJ, Gu S, Wang X, Bonewald LF, Sprague E, Jiang JX. Mechanical strain opens connexin 43 hemichannels in osteocytes: a novel mechanism for the release of prostaglandin. Mol Biol Cell. July 2005;16(7):3100-3106.
1990	Thompson JP, Pearce RH, Schechter MT, Adams ME, Tsang IK, Bishop PB. Preliminary evaluation of a scheme for grading the gross morphology of the human intervertebral disc. Spine. May 1990;15(5):411-415.
2005	Iatridis JC, MacLean JJ, Ryan DA. Mechanical damage to the intervertebral disc annulus fibrosus subjected to tensile loading. J Biomech. March 2005;38(3):557-565.
1996	Antoniou J, Steffen T, Nelson F, Winterbottom N, Hollander AP, Poole RA, Aebi M, Alini M. The human lumbar intervertebral disc: evidence for changes in the biosynthesis and denaturation of the extracellular matrix with growth, maturation, ageing, and degeneration. J Clin Invest. August 15, 1996;98(4):996-1003.
1997	Handa T, Ishihara H, Ohshima H, Osada R, Tsuji H, Obata K. Effects of hydrostatic pressure on matrix synthesis and matrix metalloproteinase production in the human lumbar intervertebral disc. Spine. May 15, 1997;22(10):1085-1091.
1998	Cohen NP, Foster RJ, Mow VC. Composition and dynamics of articular cartilage: structure, function, and maintaining healthy state. J Orthop Sports Phys Ther. October 1998;28(4):203-215.
1994	Kim Y-J, Sah RLY, Grodzinsky AJ, Plaas AHK, Sandy JD. Mechanical regulation of cartilage biosynthetic behavior: physical stimuli. Arch Biochem Biophys. May 1994;311(1):1-12.
1997	Poole CA. Articular cartilage chondrons: form, function and failure. J Anat. 1997;191(1):1-13.
1981	Doty SB. Morphological evidence of gap junctions between bone cells. Calcif Tiss Int. 1981;33(5):509-512.
2004	Wagner DR, Lotz JC. Theoretical model and experimental results for the nonlinear elastic behavior of human annulus fibrosus. J Orthop Res. July 2004;22(4):901-909.
2001	Graverand M-PHL, Ou Y, Schield-Yee T, Barclay L, Hart D, Natsume T, Rattner JB. The cells of the rabbit meniscus: their arrangement, interrelationship, morphological variations and cytoarchitecture. J Anat. May 2001;198(5):525-535.
2001	Gruber HE, Ma D, Hanley EN Jr, Ingram J, Yamaguchi DT. Morphologic and molecular evidence for gap junctions and connexin 43 and 45 expression in annulus fibrosus cells from the human intervertebral disc. J Orthop Res. September 2001;19(5):985-989.
2004	Walsh AJL, Lotz JC. Biological response of the intervertebral disc to dynamic loading. J Biomech. March 2004;37(3):329-337.
2004	Roughley PJ. Biology of intervertebral disc aging and degeneration: involvement of the extracellular matrix. Spine. December 1, 2004;29(23):2691-2699.
1996	Adams MA, McNally DS, Dolan P. “Stress” distributions inside intervertebral discs: the effects of age and degeneration. J Bone Joint Surg. November 1996;78B(6):965-972.
2002	Bruehlmann SB, Rattner JB, Matyas JR, Duncan NA. Regional variations in the cellular matrix of the annulus fibrosus of the intervertebral disc. J Anat. August 2002;201(2):159-171.
2001	Cheng B, Zhao S, Luo J, Sprague E, Bonewald LF, Jiang JX. Expression of functional gap junctions and regulation by fluid flow in osteocyte-like MLO-Y4 cells. J Bone Miner Res. February 2001;16(2):249-259.
1998	Errington RJ, Puustjarvi K, White IRF, Roberts S, Urban JPG. Characterisation of cytoplasm-filled processes in cells of the intervertebral disc. J Anat. April 1998;192(3):369-378.
2000	Adams MA, Freeman BJC, Morrison HP, Nelson IW, Dolan P. Mechanical initiation of intervertebral disc degeneration. Spine. July 1, 2000;25(13):1625-1636.
1996	Ebara S, Iatridis JC, Setton LA, Foster RJ, Mow VC, Weidenbaum M. Tensile properties of nondegenerate human lumbar anulus fibrosus. Spine. March 15, 1996;21(4):452-461.
1960	Nachemson A. Lumbar intradiscal pressure: experimental studies on post-mortem material. Acta Orthop Scand. 1960;31(suppl 43):1-104.
1999	Burger EH, Klein-Nulend J. Mechanotransduction in bone: role of the lacunocanalicular network. FASEB J. May 1999;12(9001):S101-S112.
1982	Viidik A, Danielsen CC, Oxlund H. On fundamental and phenomenological models, structure and mechanical properties of collagen, elastin and glycosaminoglycan complexes. Biorheology. 1982;19(3):437-451.
2002	Hunter CJ, Imler SM, Malaviya P, Nerem RM, Levenston ME. Mechanical compression alters gene expression and extracellular matrix synthesis by chondrocytes cultured in collagen I gels. Biomaterials. February 15, 2002;23(4):1249-1259.
2002	Boos N, Weissbach S, Rohrbach H, Weiler C, Spratt KF, Nerlich AG. Classification of age-related changes in lumbar intervertebral discs. Spine. December 1, 2002;27(23):2631-2644.

Year

Entry

1999

Guilak F, Ting-Beall HP, Baer AE, Trickey WR, Erickson GR, Setton LA. Viscoelastic properties of intervertebral disc cells: identification of two biomechanically distinct cell populations. Spine. December 1, 1999;24(23):2475-2483.

1975

Maroudas A, Stockwell RA, Nachemson A, Urban J. Factors involved in the nutrition of the human lumbar intervertebral disc: cellularity and diffusion of glucose in vitro. J Anat. September 1975;120(1):113-130.

1987

Stokes IAF. Surface strain on human intervertebral discs. J Orthop Res. 1987;5(3):348-355.

2002

Rubin C, Turner AS, Mallinckrodt C, Jerome C, Mcleod K, Bain S. Mechanical strain, induced noninvasively in the high-frequency domain, is anabolic to cancellous bone, but not cortical bone. Bone. March 2002;30(3):445-452.

2005

Cherian PP, Siller-Jackson AJ, Gu S, Wang X, Bonewald LF, Sprague E, Jiang JX. Mechanical strain opens connexin 43 hemichannels in osteocytes: a novel mechanism for the release of prostaglandin. Mol Biol Cell. July 2005;16(7):3100-3106.

1990

Thompson JP, Pearce RH, Schechter MT, Adams ME, Tsang IK, Bishop PB. Preliminary evaluation of a scheme for grading the gross morphology of the human intervertebral disc. Spine. May 1990;15(5):411-415.

2005

Iatridis JC, MacLean JJ, Ryan DA. Mechanical damage to the intervertebral disc annulus fibrosus subjected to tensile loading. J Biomech. March 2005;38(3):557-565.

1996

Antoniou J, Steffen T, Nelson F, Winterbottom N, Hollander AP, Poole RA, Aebi M, Alini M. The human lumbar intervertebral disc: evidence for changes in the biosynthesis and denaturation of the extracellular matrix with growth, maturation, ageing, and degeneration. J Clin Invest. August 15, 1996;98(4):996-1003.

1997

Handa T, Ishihara H, Ohshima H, Osada R, Tsuji H, Obata K. Effects of hydrostatic pressure on matrix synthesis and matrix metalloproteinase production in the human lumbar intervertebral disc. Spine. May 15, 1997;22(10):1085-1091.

1998

Cohen NP, Foster RJ, Mow VC. Composition and dynamics of articular cartilage: structure, function, and maintaining healthy state. J Orthop Sports Phys Ther. October 1998;28(4):203-215.

1994

Kim Y-J, Sah RLY, Grodzinsky AJ, Plaas AHK, Sandy JD. Mechanical regulation of cartilage biosynthetic behavior: physical stimuli. Arch Biochem Biophys. May 1994;311(1):1-12.

1997

Poole CA. Articular cartilage chondrons: form, function and failure. J Anat. 1997;191(1):1-13.

1981

Doty SB. Morphological evidence of gap junctions between bone cells. Calcif Tiss Int. 1981;33(5):509-512.

2004

Wagner DR, Lotz JC. Theoretical model and experimental results for the nonlinear elastic behavior of human annulus fibrosus. J Orthop Res. July 2004;22(4):901-909.

2001

Graverand M-PHL, Ou Y, Schield-Yee T, Barclay L, Hart D, Natsume T, Rattner JB. The cells of the rabbit meniscus: their arrangement, interrelationship, morphological variations and cytoarchitecture. J Anat. May 2001;198(5):525-535.

2001

Gruber HE, Ma D, Hanley EN Jr, Ingram J, Yamaguchi DT. Morphologic and molecular evidence for gap junctions and connexin 43 and 45 expression in annulus fibrosus cells from the human intervertebral disc. J Orthop Res. September 2001;19(5):985-989.

2004

Walsh AJL, Lotz JC. Biological response of the intervertebral disc to dynamic loading. J Biomech. March 2004;37(3):329-337.

2004

Roughley PJ. Biology of intervertebral disc aging and degeneration: involvement of the extracellular matrix. Spine. December 1, 2004;29(23):2691-2699.

1996

Adams MA, McNally DS, Dolan P. “Stress” distributions inside intervertebral discs: the effects of age and degeneration. J Bone Joint Surg. November 1996;78B(6):965-972.

2002

Bruehlmann SB, Rattner JB, Matyas JR, Duncan NA. Regional variations in the cellular matrix of the annulus fibrosus of the intervertebral disc. J Anat. August 2002;201(2):159-171.

2001

Cheng B, Zhao S, Luo J, Sprague E, Bonewald LF, Jiang JX. Expression of functional gap junctions and regulation by fluid flow in osteocyte-like MLO-Y4 cells. J Bone Miner Res. February 2001;16(2):249-259.

1998

Errington RJ, Puustjarvi K, White IRF, Roberts S, Urban JPG. Characterisation of cytoplasm-filled processes in cells of the intervertebral disc. J Anat. April 1998;192(3):369-378.

2000

Adams MA, Freeman BJC, Morrison HP, Nelson IW, Dolan P. Mechanical initiation of intervertebral disc degeneration. Spine. July 1, 2000;25(13):1625-1636.

1996

Ebara S, Iatridis JC, Setton LA, Foster RJ, Mow VC, Weidenbaum M. Tensile properties of nondegenerate human lumbar anulus fibrosus. Spine. March 15, 1996;21(4):452-461.

1960

Nachemson A. Lumbar intradiscal pressure: experimental studies on post-mortem material. Acta Orthop Scand. 1960;31(suppl 43):1-104.

1999

Burger EH, Klein-Nulend J. Mechanotransduction in bone: role of the lacunocanalicular network. FASEB J. May 1999;12(9001):S101-S112.

1982

Viidik A, Danielsen CC, Oxlund H. On fundamental and phenomenological models, structure and mechanical properties of collagen, elastin and glycosaminoglycan complexes. Biorheology. 1982;19(3):437-451.

2002

Hunter CJ, Imler SM, Malaviya P, Nerem RM, Levenston ME. Mechanical compression alters gene expression and extracellular matrix synthesis by chondrocytes cultured in collagen I gels. Biomaterials. February 15, 2002;23(4):1249-1259.

2002

Boos N, Weissbach S, Rohrbach H, Weiler C, Spratt KF, Nerlich AG. Classification of age-related changes in lumbar intervertebral discs. Spine. December 1, 2002;27(23):2631-2644.

Year	Entry
2007	Desrochers J. Intercellular Communication and in Situ Strains in the Annulus Fibrosus Under High Flexion Loads [Master's thesis]. Calgary, AB: University of Calgary; June 2007.
2009	McMillian JL. Cell Morphology and Gap Junction Communication in the Annulus Fibrosus [Master's thesis]. Calgary, AB: University of Calgary; August 2009.

Year

Entry

2007

Desrochers J. Intercellular Communication and in Situ Strains in the Annulus Fibrosus Under High Flexion Loads [Master's thesis]. Calgary, AB: University of Calgary; June 2007.

2009

McMillian JL. Cell Morphology and Gap Junction Communication in the Annulus Fibrosus [Master's thesis]. Calgary, AB: University of Calgary; August 2009.