Roles of Decorin and Biglycan in Tendon Repair
Small leucine-rich proteoglycans (SLRPs) are extracellular matrix molecules that are important in the fundamental processes of growth, aging, and repair. The expression and accumulation of two SLRPs common in tendon, decorin and biglycan, differ dramatically during these processes; however, their specific roles remain unknown. The overall objective of this study is to evaluate the roles of decorin and biglycan and to assess how these processes are altered by changes in their expression. To satisfy this objective, we will use knockout mice, employing a patellar tendon injury model previously developed in our lab. Briefly, a plastic-coated backing is placed beneath the tendon to offer support (1). A 0.75 mm biopsy punch is used to create a full thickness partial transection of the tendon (2). Removal of the backing leaves a distinct and reproducible injury (3). Healing will be assessed through biomechanical testing as well as other biological and organizational assays at various post-injury time points.
To satisfy this objective, we will use knockout mice, employing a patellar
tendon injury model previously developed in our lab. Briefly, a plastic-coated
backing is placed beneath the tendon to offer support (1). A 0.75 mm biopsy
punch is used to create a full thickness partial transection of the tendon
(2). Removal of the backing leaves a distinct and reproducible injury (3).
Healing will be assessed through biomechanical testing as well as other
biological and organizational assays at various post-injury time points.
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This study is designed to help explain the mechanical and structural results so as to begin to elucidate potential mechanisms responsible for the differential roles of decorin and biglycan with growth and aging. This information will allow further investigation into the contrasting and potentially compensatory roles of these SLRPs that may aid in design of improved treatment modalities for tendon injuries.
For more information see:
Huang TF, Robinson PS, Kazam E, Iozzo RV, Soslowsky LJ: Elastic and viscoelastic mechanical properties of patellar tendons from decorin and biglycan knockout mice, Trans Orthop Res Soc 29:854, 2004.
Lin TW, Cardenas L, Glaser DL, Soslowsky LJ: Utilizing knockout mice to investigate the roles of interleukins 4 and 6 in tendon healing, Trans Orthop Res Soc 29: 266, 2004.
Robinson PS, Huang TF, Kazam E, Iozzo RV, Birk DE, Soslowsky LJ: Influence of Decorin and Biglycan on Mechanical Properties of Multiple Tendons in Knockout Mice, J Biomech Eng 127(1):181-5, 2005.
Lin TW, Cardenas L, Glaser DL, Soslowsky LJ: Tendon healing in interleukin-4 and interleukin-6 knockout mice, J Biomech 39(1):61-9, 2006.
Beason DP, Zgonis MH, Ansorge HL, Birk DE, Soslowsky LJ: Healing in a Mouse Patellar Tendon Injury Model: Effect of Age, Trans Orthop Res Soc 32:885, 2007.