title: Effects of interleukin-1 receptor antagonist on collagen and matrix metalloproteinases in stress-shielded achilles tendons of rats.
abstract: Based on previous studies showing that interleukin-1 (IL-1) significantly increased after stress shielding, this article reports further research into the possible therapeutic applications of IL-1 receptor antagonist (IL-1Ra). Forty rats whose left Achilles tendons were denervated and completely stress shielded were divided into 5 groups: 2-week phosphate-buffered saline (PBS); 4-week PBS; 2-week IL-1Ra; 4-week IL-1Ra; and normal control. The Achilles tendons were tested morphologically, and the changes in collagen I and III, matrix metalloproteinases (MMP)-1 and -3, and tissue inhibitors of metalloproteinase (TIMP)-1 were determined. The collagen fibrils in the IL-1Ra groups were morphologically more similar to those in the control group than to those in the PBS groups. The collagen I levels increased in the 2-week groups. Significant differences existed between the PBS and IL-1Ra groups at 4 weeks. The MMP-1 level increased dramatically after stress shielding and increased less in the 2-week IL-1Ra group than in the 2-week PBS group. The degree of decrease of MMP-3 in the IL-1Ra groups was significantly less than that in the PBS groups. The collagen III and TIMP-1 levels continued to increase, and no difference was found between the PBS and IL-1Ra groups. Interleukin-1 receptor antagonist prevented morphological deterioration and collagen metabolism of the denervated Achilles tendons after stress shielding, likely by inhibiting the decline of MMP-3 and increasing MMP-1 levels at an early stage.
authors.affiliation: Department of Rehabilitation Medicine, the Affiliated Sixth People’s Hospital of Shanghai Jiaotong University, Shanghai, China. myhmyh2006@126.com
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Ma
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Yan
authors.forename: Huakun
authors.initials: H
authors.lastname: Zhao
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
mesh_terms: D000125:Achilles Tendon / Q000187:drug effects / Q000294:innervation / Q000378:metabolism* / Q000648:ultrastructure; D000818:Animals; D003094:Collagen / Q000032:analysis / Q000378:metabolism*; D024042:Collagen Type I / Q000032:analysis / Q000378:metabolism; D024061:Collagen Type III / Q000032:analysis / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism; D007267:Injections; D053590:Interleukin 1 Receptor Antagonist Protein / Q000008:administration & dosage / Q000378:metabolism / Q000502:physiology*; D008297:Male; D020781:Matrix Metalloproteinase 1 / Q000032:analysis / Q000378:metabolism; D019278:Matrix Metalloproteinase 3 / Q000032:analysis / Q000378:metabolism; D020782:Matrix Metalloproteinases / Q000032:analysis / Q000378:metabolism*; D046529:Microscopy, Electron, Transmission; D023421:Models, Animal; D051381:Rats; D017207:Rats, Sprague-Dawley; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000032:analysis / Q000378:metabolism
chemical_list: D024042:Collagen Type I; D024061:Collagen Type III; D053590:Interleukin 1 Receptor Antagonist Protein; D019715:Tissue Inhibitor of Metalloproteinase-1; D003094:Collagen; D020782:Matrix Metalloproteinases; D019278:Matrix Metalloproteinase 3; D020781:Matrix Metalloproteinase 1