We report chondrocyte phenotype and ectopic ossification in a collagenase-induced patellar tendon injury model. Collagenase or saline was injected intratendinously in one limb. The patella tendon was harvested for assessment at different times. There was an increase in cellularity, vascularity, and loss of matrix organization with time after collagenase injection. The tendon did not heal histologically until week 32. Ectopic mineralization as indicated by von Kossa staining started from week 8. Tendon calcification was mediated by endochondral ossification, as shown by expression of type X collagen. viva CT imaging and polarization microscopy showed characteristic bony porous structures and collagen fiber arrangement, respectively, in the calcific regions. Marrow-like cells and blood vessels were observed inside calcific deposits. Chondrocyte-like cells as indicated by morphology, expression of type II collagen, and sox 9 were seen around and embedded inside the calcific deposits. Fibroblast-like cells expressed type II collagen and sox 9 at earlier times, suggesting that erroneous differentiation of healing tendon fibroblasts may account for failed healing and ossification in collagenase-induced tendon degeneration. Because this animal model replicates key histopathological changes in calcific tendinopathy, it can be used as a model for the study of its pathogenesis at the patellar tendon.
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http://dx.doi.org/10.1369/jhc.2008.952143 | DOI Listing |
NPJ Regen Med
March 2023
Laboratory of Biomimetic Nanomaterials, Department of Orthodontics, Peking University School and Hospital of Stomatology, Beijing, 100081, China.
Macrophages are involved mainly in the balance between inflammation and tenogenesis during the healing process of tendinopathy. However, etiological therapeutic strategies to efficiently treat tendinopathy by modulating macrophage state are still lacking. In this study, we find that a small molecule compound Parishin-A (PA) isolated from Gastrodia elata could promote anti-inflammatory M2 macrophage polarization by inhibiting gene transcription and protein phosphorylation of signal transducers and activators of transcription 1.
View Article and Find Full Text PDFRegen Ther
June 2020
Division of Tissue Engineering, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
Introduction: Achilles tendinopathy is characterized by scar formation or ectopic ossification, both of which result in pain and worsened physical function in athletes and older people. Although cell therapy using adipose-derived stem cells (ASCs) has been shown to be effective for tendinopathy, the underlying mechanisms by which ASCs result in tendon healing in vivo have not yet been fully clarified.
Methods: ASCs were obtained from the fat pads of EGFP transgenic mice by collagenase digestion.
Osteoarthritis Cartilage
May 2016
Experimental Rheumatology, Radboud university medical center, Nijmegen, The Netherlands. Electronic address:
Objective: A relation between osteoarthritis (OA) and increased cholesterol levels is apparent. In the present study we investigate OA pathology in apolipoprotein E (ApoE)(-)(/-) mice with and without a cholesterol-rich diet, a model for high systemic low density lipoprotein (LDL) cholesterol levels independent of weight.
Method: Wild type (WT), Apoe(-)(/-), S100a9(-/-) and Apoe(-)(/-)S100a9(-/-) mice (C57BL/6 background) received a standard or cholesterol-rich diet.
Int J Clin Exp Pathol
September 2016
West China Hospital of Stomatology, State Key Laboratory of Oral Diseases, Sichuan University Chengdu 610041, Sichuan, China.
Purpose: The goals of this study were to characterize subchondral bone changes, and to determine biological activity characteristics of progenitor cell populations from subchondral bone in the collagenase-induced temporomandibular joint osteoarthritis (TMJOA) rabbit model. Greater understanding of such pathological changes occurring in TMJOA samples is critical in the future treatment modalities regarding cartilage protection and repair. Furthermore, the use of progenitor cell populations in various cartilage regeneration strategies proves to be a fruitful avenue for research and clinical applications.
View Article and Find Full Text PDFCan J Physiol Pharmacol
June 2015
Laboratory of Toxicology, Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-ourai-kita, Izumisano-shi, Osaka 598-8531, Japan., Department of Veterinary Clinical Pathobiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
The effect of acute osteoarthritis (OA) on peripheral nerve fibers (NFs) in synovial tissue, and their association with histological changes were investigated in collagenase-induced OA mice. Collagenase (10 U in 5 μL saline) was injected into the right knee, and the same volume of saline was injected into the left knee as the control. Mice were sacrificed 1, 2, 3, and 4 weeks after the collagenase injection.
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