Tendon matrix composition and turnover in relation to functional requirements.
Tendons are dense regular connective tissue structures that are defined based on their anatomical position of connecting muscle to bone. Despite these obvious commons features tendons from different locations within the body show remarkable variation in terms of their morphological, molecular and mechanical properties which relates to their specialized function. An appreciation of these differences is necessary to understand all aspects of tendon biology in health and disease. In our work, we have used a combination of mechanical assessment, histological measurements and molecular analysis of matrix in functionally distinct tendons to determine relationships between function and structure. We have found significant differences in material and molecular properties between spring-like tendons that are subjected to high strains during locomotion and positional tendons which are subjected to much lower strains. Furthermore, we have data to suggest that not only is the matrix composition different but also the ability of cells to synthesize and degrade the matrix (matrix turnover) varies between tendon types. We propose that these differences relate to the magnitude of strain that the tendon experiences during normal activities in life. Tendon cells may be preprogrammed during embryological development for the strain they will encounter in life or may simply respond to the particular strain environment they are subjected to. The elucidation of controlling mechanisms resulting in tendon cell specialization will have important consequences for cell based therapies and engineering strategies to repair damaged tendons.
Birch
Helen L
HL
Institute of Orthopaedics and Musculoskeletal Science, University College London, Stanmore, UK. h.birch@ucl.ac.uk
D000818:Animals; D004548:Elasticity; D005109:Extracellular Matrix / Q000502:physiology*; D006736:Horses / Q000502:physiology; D006801:Humans; D013314:Stress, Mechanical; D013710:Tendons / Q000378:metabolism / Q000502:physiology*
J Exp Biol. 2000 Apr;203(Pt 8):1317-27
10729280
PLoS Genet. 2006 Jul;2(7):e119
16895450
Nature. 2001 Dec 20-27;414(6866):895-9
11780059
Comp Biochem Physiol A Mol Integr Physiol. 2002 Dec;133(4):987-1000
12485688
Comp Biochem Physiol A Mol Integr Physiol. 2002 Dec;133(4):1001-11
12485689
Acta Physiol Scand. 2003 Feb;177(2):185-95
12558555
J Morphol. 2003 Oct;258(1):106-14
12905538
Glycoconj J. 2002 May-Jun;19(4-5):287-93
12975607
J Biomech. 2003 Oct;36(10):1529-53
14499302
Equine Vet J. 2004 May;36(4):346-50
15163043
Equine Vet J. 2004 May;36(4):365-7
15163047
Connect Tissue Res. 1978;6(1):11-23
149646
Am J Physiol. 1987 Jan;252(1 Pt 1):C1-9
3544859
Am J Vet Res. 1989 Jul;50(7):1089-95
2774333
J Bone Joint Surg Am. 1991 Dec;73(10):1507-25
1748700
Foot Ankle. 1993 Oct;14(8):443-9
8253436
Ann Rheum Dis. 1994 Jun;53(6):359-66
8037494
Acta Orthop Scand. 1996 Oct;67(5):479-81
8948254
J Cell Biol. 1997 Feb 10;136(3):729-43
9024701
Equine Vet J. 1998 Nov;30(6):534-9
9844973
J Biol Chem. 1999 Apr 2;274(14):9636-47
10092650
Equine Vet J. 1999 Sep;31(5):391-6
10505954
BMJ. 2004 Dec 4;329(7478):1328-33
15576744
J Biomech. 2005 Mar;38(3):605-8
15652560
Foot Ankle Clin. 2005 Jun;10(2):293-308
15922920
N Z Vet J. 2005 Jun;53(3):184-92
16012588
J Exp Biol. 2005 Dec;208(Pt 24):4715-25
16326953
Rheumatology (Oxford). 2006 May;45(5):508-21
16490749
J Biomech. 2000 Nov;33(11):1453-9
10940404