Disease relevance of COMP

• COMP was identified in scarred skin and granulation tissue but not in normal skin, chronic fibrosis, or a fibrosarcomatous skin growth [1].
• Pseudoachondroplasia and multiple epiphyseal dysplasia are two dominantly inherited chondrodysplasias associated with mutations in cartilage oligomeric matrix protein (COMP) [2].
• Data regarding displaced abomasum (DA), ketosis (KET), mastitis (MAST), lameness (LAME), cystic ovaries (CYST), and metritis (MET) were collected between January 1, 2001 and December 31, 2003 in herds using Dairy Comp 305, DHI-Plus, or PCDART herd management software programs [3].
• In 1933, M.H. Jacobs (J. Cell. Comp. Physiol. 4, 161-183) developed the theoretical basis for calculating permeability constants of nonelectryolytes passively penetrating erythrocytes from experimentally determined hemolysis times in isotonic solution of penetrating solute [4].

High impact information on COMP

• We developed a cell culture model by expressing mutant COMP in bovine primary chondrocytes using a gutless adenoviral vector [5].
• The secretion of mutant COMP was markedly delayed, presumably due to a prolonged association with chaperones in the endoplasmic reticulum (ER) [5].
• Disruption of extracellular matrix structure may cause pseudoachondroplasia phenotypes in the absence of impaired cartilage oligomeric matrix protein secretion [2].
• RT-PCR analysis showed that the expression levels of MMP-3, type II collagen, and COMP messenger RNA, which are tightly associated with the activation of RAR, RXR, or Sp-1, were up-regulated by treatment with HA(6) [6].
• METHODS: COMP fragments were generated in vitro by treating (a) bovine articular cartilage with interleukin-1alpha (IL-1alpha), (b) purified bovine COMP with MMPs, and (c) articular cartilage with MMPs [7].

Biological context of COMP

• The different kinetics of COMP and collagen expression suggest differential regulation at the level of transcription [8].
• Immunostaining and metabolic labelling experiments confirmed the switch in the collagen expression pattern and the rapid down-regulation of de novo synthesis of COMP and collagen IX [8].
• Arthritis score was monitored visually, and joint pathology was examined by histology, and serum cartilage oligomeric matrix protein (COMP) measured [9].
• An abundant matrix protein was purified under native conditions from adult bovine tendon and identified as cartilage oligomeric matrix protein (COMP) by immunochemical crossreaction, amino acid sequence identity of tryptic peptides derived from both N- and C-terminal regions, and structure revealed by electron microscopy [10].
• The rhodopsin (Rh) of the lizard Anolis carolinensis has only been detected in the pineal gland which controls circadian rhythms [Foster et al., J. Comp. Physiol. (1993) 33-45] [11].

Anatomical context of COMP

• Expression of the cDNA in COS cells showed that COMP is a homopolymer composed of five identical disulfide-linked subunits [12].
• The expression levels of the of chondrocyte specific genes: sox9, collagen type II, aggrecan, and COMP were measured by quantitative "Real Time" RT-PCR, and genes distribution in the hydrogel beads were localized by in situ hybridization [13].
• Immunohistochemistry showed age-dependent differences in distribution of COMP in tendon [10].
• With the recent discovery of a COMP gene mutation causing pseudoachondroplasia (Hecht et al., 1995), in which lax tendons and ligaments are a feature, the present data suggest that COMP is synthesized in response to, and is necessary for tendon to resist, load [1].
• In the present study, the ultrastructural localization of COMP in porcine immature joint cartilage and growth plate cartilage was semiquantitatively delineated [14].

Associations of COMP with chemical compounds

• RESULTS: IL-1alpha stimulation of cartilage resulted in a fragmentation of COMP, which was inhibited by MMP inhibitors CGS 27023A and BB-94 [7].
• Mean COMP levels in digital flexor tendon were approximately 2-5mg/g wet weight, but they showed a large variation [1].
• The %COMP alpha(t) was positively correlated to the percentage of CTC pattern AR (P <.001) and negatively correlated to the percentages of patterns F and B (-0.33 to -0.60, P <.05 to P <.001) [15].
• Tissues were fixed in a mixture of low concentration glutar- and paraformaldehyde, embedded at low temperature, and subjected to immunocytochemistry using polyclonal antibodies raised against bovine COMP [14].
• Incubation with anti-beta1 integrin blocking antibodies abolished the mechanosensitivity of COMP expression [16].

Other interactions of COMP

• Cyclic tension also upregulated the expression of type 2 collagen, COMP and lubricin, but did not change the expression of SOX9 and aggrecan [17].
• Cyclic compression of articular cartilage at 0.1 Hz and higher was consistently associated with a dramatic increase in the synthesis of COMP as well as fibronectin [18].
• In addition an oligomeric matrix protein initially identified in cartilage (COMP), aggrecan, and biglycan were present [19].
• Inhibition of interleukin-1alpha-induced cartilage oligomeric matrix protein degradation in bovine articular cartilage by matrix metalloproteinase inhibitors: potential role for matrix metalloproteinases in the generation of cartilage oligomeric matrix protein fragments in arthritic synovial fluid [7].

Analytical, diagnostic and therapeutic context of COMP

• Cloning and sequence analysis of cartilage oligomeric matrix protein (COMP) cDNA, representing a cartilage pentameric protein, revealed a protein of 755 amino acid residues with a calculated molecular mass of 82,700 Da [12].
• The fragments generated in each case were analyzed by Western blot, using an antibody to the C-terminal heptadecapeptide of COMP [7].
• Equine tendon COMP was purified by ion exchange chromatography and gel filtration and used in a heterologous inhibition ELISA to quantify COMP in equine digital flexor tendons at different ages, and in other tendons and ligaments [1].
• COMP expression was assessed by means of semi-quantitative RT-PCR and Northern blot techniques [16].
• The responses to the treatments were assessed using a combination of radio-labeling for total protein synthesis and an ELISA for quantification of Cartilage Oligomeric Matrix Protein (COMP) production [20].

References