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Skeletal Embryology and Limb Growth
Published in Manoj Ramachandran, Tom Nunn, Basic Orthopaedic Sciences, 2018
Rick Brown, Anish Sanghrajka, Deborah Eastwood
Multiple epiphyseal dysplasia (MED), a defect in ossification of the epiphysis, occurs in both autosomal and recessive forms. Both types affect the hips and knees, but the recessive type is commonly associated with scoliosis and deformities of the hands and knees. 70% of the dominant forms are due to mutations in the gene coding the cartilage oligometric matrix protein (COMP).
Tissue Engineering of Articular Cartilage
Published in Kyriacos A. Athanasiou, Eric M. Darling, Grayson D. DuRaine, Jerry C. Hu, A. Hari Reddi, Articular Cartilage, 2017
Kyriacos A. Athanasiou, Eric M. Darling, Grayson D. DuRaine, Jerry C. Hu, A. Hari Reddi
Cartilage matrix protein (CMP), not to be confused with cartilage oligomeric matrix protein (COMP), is expressed almost exclusively in cartilage (Choi et al. 1983). CMP binds to aggrecan and type II collagen, and chondrocytes attach to it via the α1β1 integrin. When used as a coating material, CMP enhanced both cell attachment and spreading on surfaces (Makihira et al. 1999). The addition of type II collagen to the CMP coating showed an improvement in these characteristics. Because CMP is specific to cartilage tissue, it might be a more appropriate protein to target for coating purposes, although issues such as ease of production and cost would certainly be important factors.
Genetic disorders, skeletal dysplasias and malformations
Published in Ashley W. Blom, David Warwick, Michael R. Whitehouse, Apley and Solomon’s System of Orthopaedics and Trauma, 2017
Fergal Monsell, Martin Gargan, Deborah Eastwood, James Turner, Ryan Katchky
Pseudoachondroplasia is a disproportionate, short limb dysplasia that is associated with significant short stature, limb malalignment and severe ligamentous laxity. It is an autosomal dominant disorder, affecting the cartilage oligomeric matrix protein gene (COMP) on chromosome 19. Secretion of COMP is disrupted and accumulates in chondrocytes, causing cell death and inhibiting epiphyseal cartilage growth and development.
Expression of cartilage oligomeric matrix protein in periampullary adenocarcinoma is associated with pancreatobiliary-type morphology, higher levels of fibrosis and immune cell exclusion
Published in OncoImmunology, 2022
Konstantinos S. Papadakos, Sebastian Lundgren, Chrysostomi Gialeli, Patrick Micke, Artur Mezheyeuski, Jacob Elebro, Karin Jirström, Anna M. Blom
Cartilage oligomeric matrix protein (COMP) is a large pentameric protein that under normal conditions is almost exclusively expressed in the cartilage. COMP is a regulator of the extracellular matrix (ECM) assembly.1 Fibrosis is characterized by excessive production of ECM proteins, which leads to stiffening of the tissue causing cellular stress and organ malfunction.2 COMP is highly expressed in fibrotic diseases, such as scleroderma,3 idiopathic pulmonary fibrosis,4 and liver fibrosis.5,6 Under fibrotic conditions, COMP plays a vital role in the organization of ECM and regulates type I and II collagen7 production and fibrillogenesis.8 Moreover, in COMP knockout mice, the organization of collagen fibers is unraveled, and development of fibrosis attenuated. Moreover, fibroblasts lacking expression of COMP are unable to secret and deposit collagens into the ECM, leading to intracellular stress due to collagen accumulation in the endoplasmic reticulum.9
Objective and noninvasive biochemical markers in rheumatoid arthritis: where are we and where are we going?
Published in Expert Review of Proteomics, 2021
Anne C. Bay-Jensen, Anne Sofie Siebuhr, Dres Damgaard, Patryk Drobinski, Christian Thudium, Joachim Mortensen, Claus H Nielsen
Collagens are the most abundant proteins in connective tissues, including the various joint tissues, and are ubiquitously expressed throughout all organs and tissues in the body [93]. Forty-two different collagen genes, coding for 28 different types of collagens, have been identified thus far [93]. Collagens are trimeric molecules composed of three polypeptide α-chains that constitute a triple helix characteristic of the collagen superfamily [93,94]. The molecular structure and supramolecular assembly of collagens allow their division into major subfamilies, as recently outlined by Ricard–Blum [93], who described the most important subclasses. In addition to collagens, the joints also contain a range of other matrix proteins, the most abundant of which is proteoglycan aggrecan, as well as several less abundant proteins with either structural or signaling properties, such as cartilage oligomeric protein (COMP), hyaluronic acid (HA) and fibronectin [95]. COMP is an ECM protein that binds to other ECM proteins, mainly in cartilage, and its measurement in the circulation is believed to be a marker of cartilage degradation [96].
Predictive factors for radiographic progression of large joint damage in patients with rheumatoid arthritis treated with biological disease-modifying antirheumatic drugs (bDMARDs): Results of 3 to 4 years of follow-up
Published in Modern Rheumatology, 2019
Arata Nakajima, Keiichiro Terayama, Masato Sonobe, Yasuchika Aoki, Hiroshi Takahashi, Yorikazu Akatsu, Shinji Taniguchi, Manabu Yamada, Ayako Kubota, Koichi Nakagawa
Thus far, a few papers have reported predictive factors associated with RPD to large joints. de Jong et al. showed a strong association between high serum cartilage oligomeric matrix protein (COMP) level and current damage to large joints; however, serum COMP level at baseline was not associated with an increased rate of radiological joint damage after 2 years of follow-up [21]. Recently, we demonstrated that LG was associated with RPD to large joints, with a cut-off value of 2.5 [14]. Matsushita et al. also showed that baseline LG was strongly associated with the progression of damage in the proximal weight-bearing joints of patients with RA receiving TNF-blocking therapies [22]. Furthermore, Suto et al., using 18F-fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG-PET/CT), showed that the maximum standardized uptake value (SUVmax) at baseline and DAS28-ESR at 6 months after biological treatment were significant factors for predicting destruction of large joints at 2 years [23]. These investigators also showed that a baseline SUVmax > 1.65 was a significant predictive factor for progressive damage at 3 years [24]. These studies demonstrated that imaging findings, but not the patient background characteristics that are assessed in routine clinical practice, could be predictive factors for RPD to large joints.