The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
David R Eyre - One of the best experts on this subject based on the ideXlab platform.
-
analyses of lysine aldehyde cross linking in collagen reveal that the mature cross link histidinohydroxylysinonorleucine is an artifact
Journal of Biological Chemistry, 2019Co-Authors: David R Eyre, Marya Weis, Jyoti RaiAbstract:Lysyl oxidase-generated intermolecular cross-links are essential for the tensile strength of collagen fibrils. Two cross-linking pathways can be defined, one based on Telopeptide lysine aldehydes and another on Telopeptide hydroxylysine aldehydes. Since the 1970s it has been accepted that the mature cross-linking structures on the lysine aldehyde pathway, which dominates in skin and cornea, incorporate histidine residues. Here, using a range of MS-based methods, we re-examined this conclusion and found that Telopeptide aldol dimerization is the primary mechanism for stable cross-link formation. The C-Telopeptide aldol dimers formed labile addition products with glucosylgalactosyl hydroxylysine at α1(I)K87 in adjacent collagen molecules that resisted borohydride reduction and after acid hydrolysis produced histidinohydroxylysinonorleucine (HHL), but only from species with a histidine in their α1(I) C-Telopeptide sequence. Peptide MS analyses and the lack of HHL formation in rat and mouse skin, species that lack an α1(I) C-Telopeptide histidine, revealed that HHL is a laboratory artifact rather than a natural cross-linking structure. Our experimental results also establish that histidinohydroxymerodesmosine is produced by borohydride reduction of N-Telopeptide allysine aldol dimers in aldimine intermolecular linkage to nonglycosylated α1(I) K930. Borohydride reduction of the aldimine promotes an accompanying base-catalyzed Michael addition of α1(I) H932 imidazole to the α,β-unsaturated aldol. These aldehydes are intramolecular at the N terminus but at the C terminus they can be both intramolecular and intermolecular according to present and earlier findings.
-
a chaperone complex formed by hsp47 fkbp65 and bip modulates Telopeptide lysyl hydroxylation of type i procollagen
Journal of Bone and Mineral Research, 2017Co-Authors: Ivan Duran, Mary Ann Weis, Yasemin Alanay, David R Eyre, Jorge H Martin, Pavel Krejci, Peter Konik, Caressa Lietman, Brendan Lee, Daniel H CohnAbstract:Lysine hydroxylation of type I collagen Telopeptides varies from tissue to tissue, and these distinct hydroxylation patterns modulate collagen cross-linking to generate a unique extracellular matrix. Abnormalities in these patterns contribute to pathologies that include osteogenesis imperfecta (OI), fibrosis, and cancer. Telopeptide procollagen modifications are carried out by lysyl hydroxylase 2 (LH2); however, little is known regarding how this enzyme regulates hydroxylation patterns. We identified an ER complex of resident chaperones that includes HSP47, FKBP65, and BiP regulating the activity of LH2. Our findings show that FKBP65 and HSP47 modulate the activity of LH2 to either favor or repress its activity. BiP was also identified as a member of the complex, playing a role in enhancing the formation of the complex. This newly identified ER chaperone complex contributes to our understanding of how LH2 regulates lysyl hydroxylation of type I collagen C-Telopeptides to affect the quality of connective tissues. © 2017 American Society for Bone and Mineral Research.
-
increased c Telopeptide cross linking of tendon type i collagen in fibromodulin deficient mice
Journal of Biological Chemistry, 2014Co-Authors: Sebastian Kalamajski, Mary Ann Weis, Jyoti Rai, Cuiping Liu, Viveka Tillgren, Kristofer Rubin, Ake Oldberg, David R EyreAbstract:The controlled assembly of collagen monomers into fibrils, with accompanying intermolecular cross-linking by lysyl oxidase-mediated bonds, is vital to the structural and mechanical integrity of connective tissues. This process is influenced by collagen-associated proteins, including small leucine-rich proteins (SLRPs), but the regulatory mechanisms are not well understood. Deficiency in fibromodulin, an SLRP, causes abnormal collagen fibril ultrastructure and decreased mechanical strength in mouse tendons. In this study, fibromodulin deficiency rendered tendon collagen more resistant to nonproteolytic extraction. The collagen had an increased and altered cross-linking pattern at an early stage of fibril formation. Collagen extracts contained a higher proportion of stably cross-linked α1(I) chains as a result of their C-Telopeptide lysines being more completely oxidized to aldehydes. The findings suggest that fibromodulin selectively affects the extent and pattern of lysyl oxidase-mediated collagen cross-linking by sterically hindering access of the enzyme to Telopeptides, presumably through binding to the collagen. Such activity implies a broader role for SLRP family members in regulating collagen cross-linking placement and quantity.
-
type iii collagen a fibril network modifier in articular cartilage
Journal of Biological Chemistry, 2010Co-Authors: Jiann Jiu Wu, Mary Ann Weis, David R EyreAbstract:The collagen framework of hyaline cartilages, including articular cartilage, consists largely of type II collagen that matures from a cross-linked heteropolymeric fibril template of types II, IX, and XI collagens. In the articular cartilages of adult joints, type III collagen makes an appearance in varying amounts superimposed on the original collagen fibril network. In a study to understand better the structural role of type III collagen in cartilage, we find that type III collagen molecules with unprocessed N-propeptides are present in the extracellular matrix of adult human and bovine articular cartilages as covalently cross-linked polymers extensively cross-linked to type II collagen. Cross-link analyses revealed that Telopeptides from both N and C termini of type III collagen were linked in the tissue to helical cross-linking sites in type II collagen. Reciprocally, Telopeptides from type II collagen were recovered cross-linked to helical sites in type III collagen. Cross-linked peptides were also identified in which a trifunctional pyridinoline linked both an α1(II) and an α1(III) Telopeptide to the α1(III) helix. This can only have arisen from a cross-link between three different collagen molecules, types II and III in register staggered by 4D from another type III molecule. Type III collagen is known to be prominent at sites of healing and repair in skin and other tissues. The present findings emphasize the role of type III collagen, which is synthesized in mature articular cartilage, as a covalent modifier that may add cohesion to a weakened, existing collagen type II fibril network as part of a chondrocyte healing response to matrix damage.
-
proteolysis of human bone collagen by cathepsin k characterization of the cleavage sites generating the cross linked n Telopeptide neoepitope
Bone, 2000Co-Authors: L M Atley, John S Mort, M Lalumiere, David R EyreAbstract:An immunoassay for cross-linked N-Telopeptides of type I collagen (NTx) in urine or serum has proven to give a sensitive index of osteoclast-mediated bone resorption. We show that recombinant human cathepsin K is highly active in releasing the NTx neoepitope in 100% yield from bone type I collagen. Cathepsins S, L, and B were also active but at 57%, 36%, and 27% of the yield of K, respectively. The matrix metalloproteinases that were tested, stromelysin, collagenase 3, or matrilysin, did not produce any immunoreactivity. Cathepsin K also acted on demineralized bone matrix, releasing NTx epitope and completely dissolving the bone particles in 24-48 h. Proteolytic cleavage of a G-L peptide bond in the alpha2(I)N-Telopeptide was shown to be required for recognition by monoclonal antibody 1H11. Peptide analysis identified bonds in the N-Telopeptide and helical cross-linking domains adjacent to the cross-linking residues at which cathepsin K cleaved in bone collagen. The sites were consistent with the known substrate specificity of cathepsin K, which prefers a hydrophobic residue or proline in the critical P2 position. The NTx peptides generated by cathepsin K were of low molecular weight, in the range previously found in human urine. Because cathepsin K appears to be essential for the normal resorption of mineralized bone matrix by osteoclasts, these findings help explain the specificity and responsiveness of NTx as a marker of osteoclastic bone resorption in vivo.
Juha Risteli - One of the best experts on this subject based on the ideXlab platform.
-
Serum-Based Test of the Pathologic Breakdown of Type I Collagen Fibers
2016Co-Authors: Juha Risteli, Leila RisteliAbstract:cross-linked carboxy-terminal Telopeptide of type-
-
autoantibodies binding to citrullinated Telopeptide of type ii collagen and to cyclic citrullinated peptides predict synergistically the development of seropositive rheumatoid arthritis
Annals of the Rheumatic Diseases, 2007Co-Authors: Marjakaisa Koivula, Markku Heliovaara, Jarmo Ramberg, Paul Knekt, Harri Rissanen, Timo Palosuo, Juha RisteliAbstract:Objectives: To find out whether autoantibodies to citrullinated Telopeptides of type I and II collagens and to cyclic citrullinated peptides (CCPs) predict the development of rheumatoid arthritis (RA). Methods: A case-control study (matched for sex, age and municipality) was nested within a Finnish cohort of 19072 adults who had neither arthritis nor a history of it at the baseline examination during 1973–7. 124 subjects developed RA by late 1989, and of these, 89 were positive for rheumatoid factor (RF). Preillness serum specimens were analysed for autoantibodies against arginine (A)- or citrulline (C)-containing synthetic Telopeptides using a chemiluminescence method and for anti-CCPs Mark2 with an enzyme-linked immunosorbent assay method. Results: The mean levels of autoantibodies to citrulline-containing Telopeptides and the C/A ratios of type I and II collagens and to CCP were higher in subjects who later developed RF-positive RA. In the highest tertiles of C/A (I), C/A (II) ratios and anti-CCPs levels, the relative risk of RF-positive RA was significantly increased. In the multifactorial model, only anti-CCPs retained its statistical significance. However, the interaction term of C/A (II) ratio and anti-CCPs proved to be statistically significant (p = 0.02). The subjects ranked into the highest tertiles of both C/A (II) ratio and anti-CCPs had an odds ratio of 20.06 (95% confidence interval, 4.37 to 92.06) of developing RF-positive RA compared with those in the lowest tertiles of these antibodies. None of the autoantibodies predicted RF-negative RA. Conclusion: Autoantibodies to citrullinated Telopeptides of type I and II collagen and to CCPs exert a synergistic effect on the risk of seropositive RA.
-
increased content of type iii collagen at the rupture site of human achilles tendon
Journal of Orthopaedic Research, 2002Co-Authors: Heidi Eriksen, Ari Pajala, Juhana Leppilahti, Juha RisteliAbstract:Abstract We compared the type I and III collagen amounts and cross-linked Telopeptides at the rupture site and two other sites of the same tendon. Tendon samples of ten individuals with total Achilles tendon rupture and six healthy cadavers were collected. The newly synthesized type I and III procollagens were assessed by extracting the soluble propeptides PINP, PICP and PIIINP. The insoluble matrix was solubilized by heat denaturation and trypsin digestion. Hydroxyproline, the cross-linked Telopeptide structures of type I (ICTP and SP 4) and III collagens (IIINTP) and the degradation product of type III collagen (tryptic PIIINP) were measured from the digests. The type III collagen content was significantly increased at the rupture site when compared to control sites (5- and 12-fold increased) or cadavers (5-fold increased). No changes in the amounts of newly synthesized type I and III procollagens were observed. The ICTP content decreased and the SP 4/ICTP ratio increased along with ageing, suggesting a structural change in the type of cross-link in the carboxyterminal Telopeptide of type I collagen. Type III collagen has accumulated at the rupture site probably due to microtraumas and the subsequent healing process. The increased content of type III collagen can cause thinner collagen fibers, decrease the tensile strength and may finally result in total rupture of the tendon. The age-related change in the nature of the cross-link in the carboxyterminal Telopeptide may contribute to this weakening.
-
type i and iii collagens in human colon cancer and diverticulosis
Scandinavian Journal of Gastroenterology, 2000Co-Authors: Michaela K Bode, Jyrki Makela, Tuomo J Karttunen, Leila Risteli, Juha RisteliAbstract:Background: Collagens are major proteins in the extracellular matrix, providing tissues with tensile strength. They are also important for cell adhesion and the invasion of malignant tumours. Methods: Thirty-nine samples of human colon (24 diverticulosis, 6 malignant tumours, 9 controls) were collected during elective surgery. Immunoassays for different domains of type I and III collagens and procollagens were used in soluble tissue extracts and trypsin digests of tissue samples. Results: The contents of cross-linked type I and III collagen Telopeptides and total collagen were similar in diverticulosis and healthy tissue, whereas in malignant tissue maturely cross-linked type III collagen was scarce. Furthermore, some of the cross-linked type I Telopeptide antigens were exceptionally small in size, indicating that the cross-linking of type I collagen in collagen fibres is impaired in cancer. The rate of type I collagen synthesis was clearly increased in malignancy, but not significantly in diverticulosis....
-
immunochemical characterization of assay for carboxyterminal Telopeptide of human type i collagen loss of antigenicity by treatment with cathepsin k
Bone, 2000Co-Authors: Mirjaliisa Sassi, Leila Risteli, Heidi Eriksen, S Niemi, J P Mansell, M Gowen, Juha RisteliAbstract:Abstract The assay for the cross-linked carboxyterminal Telopeptide of type I collagen (ICTP) has been shown to reflect increased type I collagen degradation in such pathological conditions as bone metastases and rheumatoid arthritis, but to be rather insensitive to the changes in physiological bone collagen turnover (e.g., induced by estrogen or bisphosphonate treatment). To determine the reasons for this discrepancy we localized the antigenic determinant recognized by the ICTP assay and studied the effects of two major osteoclastic proteinases, cathepsin K (EC 3.4.22.38) and matrix metalloproteinase-9 (MMP-9; gelatinase B; EC 3.4.24.35), on immunoreactivity. The antigenic determinant was shown to reside within the hydrophobic phenylalanine-rich regions of the carboxyterminal Telopeptides of the two α1 chains of human type I collagen, situated between the triple helical domain and the lysine-derived trivalent cross-link. This conclusion was based on differences between the amino acid sequences and cross reactivities of the corresponding human and bovine antigens before and after proteolytic treatments with chymotrypsin. A trivalent cross-link is necessary for providing such a structure, because the divalently cross-linked and monomeric natural and synthetic peptides from the same region, but containing only one phenylalanine-rich sequence, showed poor immunoreaction. Recombinant human cathepsin K cleaved the trivalently cross-linked ICTP structure at two sites between the phenylalanine-rich region and the cross-link, destroying the reactivity with ICTP antibodies. On the contrary, the treatment of isolated ICTP by the matrix metalloproteinases MMP-9 (gelatinase B), MMP-1 (collagenase 1), or MMP-13 (collagenase 3) had no effect on the immunoreaction. Our results indicate that the increased circulating concentrations of ICTP found in several clinical situations are most likely produced by matrix metalloproteinases, whereas cathepsin K-mediated, osteoclastic bone resorption destroys ICTP antigenicity.
Richard Eastell - One of the best experts on this subject based on the ideXlab platform.
-
antiresorptive effect of a cathepsin k inhibitor ono 5334 and its relationship to bmd increase in a phase ii trial for postmenopausal osteoporosis
BMC Musculoskeletal Disorders, 2017Co-Authors: Makoto Tanaka, Steve Deacon, Yoshitaka Hashimoto, Chihiro Hasegawa, Richard EastellAbstract:ONO-5334 is a cathepsin K inhibitor that induced bone mineral density (BMD) gain in a phase II study in postmenopausal osteoporosis patients. Even though the antiresorptive effect could only be monitored in the morning during the study, simulation can allow the antiresorptive effect to be assessed over 24 h, with assessment of the relationship to BMD gain. Inhibition of the serum C-Telopeptide of type I collagen (sCTX) level at doses of ONO-5334 of 100 mg once daily (QD), 300 mg QD, and 50 mg twice daily (BID) was simulated using plasma ONO-5334 pharmacokinetic (PK) data for repeated dose administration in a phase I study and corresponding sCTX inhibition from the PK-pharmacodynamic (PK/PD) relationship. sCTX was selected because it has a high signal-to-noise ratio compared to other Telopeptides. A negative sigmoidal shape for the PK/PD relationship between plasma ONO-5334 and sCTX levels was obtained in our previous study. The simulated sCTX inhibition reached >99% of the maximal inhibitory effect (Emax) at 0.5 h in all treatment groups, and decreased to <80% Emax at 8 and 12 h at 50 mg BID and 100 mg QD, respectively. However, sCTX inhibition at 300 mg QD was maintained at ≥82% Emax over 24 h. The mean sCTX inhibition rates for 24 h at 100 mg QD, 300 mg QD and 50 mg BID were 63, 95 and 80% Emax, respectively. There was a positive linear relationship by treatment group between mean sCTX inhibition over 24 h and observed BMD gain in the phase II study. The dose response for BMD with ONO-5334 at 100 and 300 mg QD and higher BMD gain at 50 mg BID vs. 100 mg QD can be explained by sCTX inhibition over 24 h. The simulation gave the antiresorptive effect of ONO-5334 over 24 h and allowed prediction of BMD gain due to ONO-5334. The registration number in The European Union Clinical Trials Register is 2007–002417-39 . The date of registration was August 31, 2007.
-
Antiresorptive effect of a cathepsin K inhibitor ONO-5334 and its relationship to BMD increase in a phase II trial for postmenopausal osteoporosis
BMC, 2017Co-Authors: Makoto Tanaka, Steve Deacon, Yoshitaka Hashimoto, Chihiro Hasegawa, Richard EastellAbstract:Abstract Background ONO-5334 is a cathepsin K inhibitor that induced bone mineral density (BMD) gain in a phase II study in postmenopausal osteoporosis patients. Even though the antiresorptive effect could only be monitored in the morning during the study, simulation can allow the antiresorptive effect to be assessed over 24 h, with assessment of the relationship to BMD gain. Methods Inhibition of the serum C-Telopeptide of type I collagen (sCTX) level at doses of ONO-5334 of 100 mg once daily (QD), 300 mg QD, and 50 mg twice daily (BID) was simulated using plasma ONO-5334 pharmacokinetic (PK) data for repeated dose administration in a phase I study and corresponding sCTX inhibition from the PK-pharmacodynamic (PK/PD) relationship. sCTX was selected because it has a high signal-to-noise ratio compared to other Telopeptides. A negative sigmoidal shape for the PK/PD relationship between plasma ONO-5334 and sCTX levels was obtained in our previous study. Results The simulated sCTX inhibition reached >99% of the maximal inhibitory effect (Emax) at 0.5 h in all treatment groups, and decreased to
-
clinical performance of immunoreactive tartrate resistant acid phosphatase isoform 5b as a marker of bone resorption
Bone, 2004Co-Authors: R A Hannon, Richard Eastell, Jackie A Clowes, Alison C Eagleton, Amna Al Hadari, A BlumsohnAbstract:Previous immunoassays developed for the measurement of serum tartrate-resistant acid phosphatase (TRACP) have lacked specificity for osteoclastic TRACP, TRACP 5b, or have not shown satisfactory clinical performance. The aim of this study was to evaluate the clinical performance of a novel immunocapture activity assay for TRACP 5b, in comparison to Telopeptide fragments of type I collagen. Within-subject variability and the effect of feeding on TRACP 5b and Telopeptides of type I collagen were assessed in 20 healthy premenopausal women. Diurnal variation of TRACP 5b and serum beta C-terminal cross-linked Telopeptide of type I collagen (sbetaCTX) was assessed in 12 healthy postmenopausal women. Renal clearance was assessed in 19 end stage renal failure patients undergoing routine haemodialysis. Response to antiresorptive treatment and calcium supplementation was assessed in osteoporotic postmenopausal women treated with alendronate and calcium (n = 16) or with calcium alone (n = 7) for 24 weeks.Within-subject variability (CVi) of TRACP 5b was 6.6%, lower than CVi of urinary and serum Telopeptides. TRACP 5b decreased by 2.4 +/- 0.8%, in response to feeding (P < 0.05) compared to 7.0 +/- 2.6% to 7.9 +/- 3.7% for urinary Telopeptides (P < 0.05 to < 0.01) and 8.5 +/- 1.7% to 17.8 +/- 2.6% for serum Telopeptides (P < 0.0001). The amplitude of the diurnal rhythm for TRACP 5b was small compared to that of sbetaCTX, 14 +/- 4% vs. 137 +/- 14%. Haemodialysis did not have a significant effect on TRACP 5b but reduced sbetaCTX by 46 +/- 4% (P < 0.0001). In response to alendronate, TRACP 5b decreased by 39 +/- 4% compared to 49 +/- 4% to 69 +/- 5% for urinary Telopeptides and 75 +/- 8% for sbetaCTX. We conclude that TRACP 5b shows an attenuated response to antiresorptive therapy in comparison with other markers of bone resorption, but that this may be offset by lower biological variability. TRACP 5b may provide useful additional information about bone resorption.
-
bone mineral density and biochemical markers of bone turnover in aseptic loosening after total hip arthroplasty
Journal of Orthopaedic Research, 2003Co-Authors: Mark J Wilkinson, I Stockley, A J Hamer, Angela Rogers, Richard EastellAbstract:The aims of this study were to determine whether subjects with aseptic loosening after total hip arthroplasty (THA) have regional differences in periprosthetic bone mineral density (BMD) and systemic biochemical markers of bone turnover compared to subjects with successful implants. Proximal femoral and pelvic BMD were measured by dual energy X-ray absorptiometry and bone turnover markers were assayed in 49 subjects 12.6±4.3 (mean±SD) years after cemented THA. Femoral BMD was lower in Gruen zones 2, 5, 6, and 7 in subjects with a loose femoral implant (n=17) compared to those (n=32) with fixed femoral implants (P<0.05 all comparisons). This BMD difference was greatest (−31%, P=0.02) in the proximal and medial region of the femur. Subjects with femoral loosening had higher levels of the bone resorption marker N-Telopeptides of type-I collagen (P=0.02) than those with a fixed femoral implant. No differences in pelvic BMD or bone turnover markers were found between subjects with loose (n=18) versus fixed (n=31) pelvic implants. This study suggests that failure of femoral components after cemented THA is associated with region-specific decreases in BMD and an increase in urinary excretion of N-Telopeptide cross-links of type-I collagen. These surrogate outcome markers may be of value in monitoring response to antiresorptive therapies used to treat periprosthetic osteolysis, although the diagnosis of aseptic loosening remains clinical and radiological.
-
response of biochemical markers of bone turnover to hormone replacement therapy impact of biological variability
Journal of Bone and Mineral Research, 1998Co-Authors: R A Hannon, A Blumsohn, K E Naylor, Richard EastellAbstract:Biochemical markers of bone turnover may be useful to monitor patients taking hormone replacement therapy (HRT). The aim of this study was to assess the utility of markers in monitoring HRT by comparing the response of a large panel of markers to HRT with their within subject variability. We measured the response of markers to transdermal estradiol in 11 postmenopausal women over 24 weeks. We measured the within subject variability of markers in 11 untreated healthy postmenopausal women over the same period. The mean decrease in markers of bone formation after 24 weeks treatment ranged from 19% for procollagen type I C-terminal propeptide (PICP) to 40% for procollagen type I N-terminal propeptide (PINP). The mean decrease in markers of bone resorption ranged from 10% for tartrate-resistant acid phosphatase (TRAP) to 67% for C-terminal cross-linked Telopeptide. The least significant change (LSC at p < 0.05), calculated from the within subject variability in the untreated group, was used to define response. LSC for osteocalcin was 21%, bone alkaline phosphatase 28%, PICP 24%, PINP 21%, type I collagen Telopeptide 28%, TRAP 17%, urinary calcium 90%, hydroxyproline 75%, total deoxypyridinoline 47%, free pyridinoline 36%, free deoxypyridinoline 26%, N-terminal cross-linked Telopeptide 70%, and C-terminal cross-linked Telopeptide 132%. The greatest number of responders after 24 weeks of treatment were found using PINP and osteocalcin (9 each), and free deoxypyridinoline (8 each) and total deoxypyridinoline (7 each). Lumbar spine bone mineral density defined four patients as responders. The ability to detect a response differs between markers and is not dependent on the magnitude of response to therapy.
Per Qvist - One of the best experts on this subject based on the ideXlab platform.
-
collagen type ii c Telopeptide fragments as an index of cartilage degradation
Bone, 2001Co-Authors: Stephan Christgau, Patrick Garnero, C Fledelius, C Moniz, M Ensig, Evelyne Gineyts, Christian Rosenquist, Per QvistAbstract:We report the development of an assay for measurement of the urinary concentration of collagen type II C-Telopeptide fragments. This assay was developed for providing a specific marker of joint metabolism. A monoclonal antibody, recognizing a linear six amino acid epitope from the middle region of the collagen type II C-Telopeptide was used in a competitive enzyme-linked immunoassay (ELISA) format for measurement of urine samples. The technical performance and specificity of the assay was evaluated and a panel of samples from patients with rheumatoid arthritis (RA) (n = 27), osteoarthritis (OA) (n = 29), Paget's disease (n = 9), and healthy controls (n = 428) was measured in the assay. The ELISA was specific for the peptide EKGPDP derived from collagen type II C-Telopeptide: it did not recognize peptides from the N-Telopeptide of the molecule or from other collagen types. Collagen type II C-Telopeptide fragments measured in the assay resisted seven freeze-thaw cycles and >20 h of storage at room temperature. RA and OA patients showed significant 2.33-fold (95% confidence interval [CI] 1.50-3.16) and 1.53-fold (CI 1.24-1.82) elevations in CartiLaps concentration, respectively. Paget's disease patients did not have elevated CartiLaps levels. RA patients with radiological evidence of cartilage damage had significantly higher (1.79-fold, CI 1.04-2.54) CartiLaps levels than RA patients without radiological evidence of cartilage destruction. The Cartilaps assay showed high technical precision and an ability to differentiate populations with an elevated joint metabolism from normal controls. This suggests that the assay may have clinical value in assisting in the diagnosis of joint diseases and in monitoring progression and therapy in RA and OA.
-
characterization of urinary degradation products derived from type i collagen identification of a β isomerized asp gly sequence within the c terminal Telopeptide α1 region
Journal of Biological Chemistry, 1997Co-Authors: Christian Fledelius, Anders H Johnsen, Paul A C Cloos, Martin Bonde, Per QvistAbstract:Abstract The heterogeneity of urinary degradation products of C-terminal Telopeptides derived from the α1 chain of human type I collagen was investigated and characterized. The urinary fragments characterized in this study consisted of two cross-linked (X) amino acid sequences derived from the C-terminal Telopeptide (α1) of type I collagen. Fragments containing the sequence EXAHDGGR, with a DG site being either nonisomerized (Asp-Gly) or β-isomerized (βAsp-Gly), were identified. Pyridinoline was detected among the pyridinium cross-links, but there was a dominance of deoxypyridinoline and a cross-link containing pyridinoline having a molecular weight identical with that of galactosyl pyridinoline. A nonfluorescent cross-link was also found. The concentration of fragments derived from the C-terminal Telopeptide region of type I collagen containing the sequence Asp-Gly (αCTX) and/or βAsp-Gly (βCTX) was measured by enzyme-linked immunosorbent assays in urine and in collagenase digests of trabecular and cortical bone of young and old origin. It was shown that the urinary ratio between such fragments, αCTX/βCTX, was higher in children compared with adults and that the ratio decreased with increasing age of bone. The results indicated that the C-terminal Telopeptide fragments derived from type I collagen excreted into urine originated mainly from bone. In conclusion, it is demonstrated for the first time that the C-terminal Telopeptide α1 chain of type I collagen contains an Asp-Gly site prone to undergo β-isomerization and that the degree of β-isomerization of this linkage apparently increases with increasing age of bone. These findings indicate that the ratio αCTX/βCTX might be clinically important in diagnosing metabolic bone diseases.
-
development of a monoclonal antibody to urinary degradation products from the c terminal Telopeptide α1 chain of type i collagen application in an enzyme immunoassay and comparison to crosslaps elisa
Scandinavian Journal of Clinical & Laboratory Investigation, 1997Co-Authors: C Fledelius, Per Qvist, I Kolding, M Bonde, Christian Hassager, Jeanyves Reginster, J Hejgaard, H Frokiaer, Claus ChristiansenAbstract:A monoclonal antibody MAbA7 was raised against a synthetic peptide having a sequence (EKAHDGGR) specific for a part of the C-Telopeptide α1 chain of type I collagen. MAbA7 was labelled with horseradish peroxide and used in a competitive one-step enzyme-linked immunosorbent assay (ELISA) for measurement of urinary type I collagen degradation products. The assay was technically evaluated and preliminary clinical data are presented. The measuring range was 200–7000 µg 1−1 with a detection limit of 25 µg 1−1. Within-run and total CVs were 5.5 and 8.0%, respectively. Analytical recovery averaged 96.6%±M5.3 (mean±1SD). Values obtained in the ELISA were highly correlated (r=0.93) to values obtained by a commercially available assay (CrossLaps™ ELISA) known to measure urinary degradation products derived from the C-Telopeptide of type I collagen reflecting the rate of bone resorption. Investigation of the urinary fragments responsible for the immunological response in the two assays revealed, however, that they a...
Jiann Jiu Wu - One of the best experts on this subject based on the ideXlab platform.
-
type iii collagen a fibril network modifier in articular cartilage
Journal of Biological Chemistry, 2010Co-Authors: Jiann Jiu Wu, Mary Ann Weis, David R EyreAbstract:The collagen framework of hyaline cartilages, including articular cartilage, consists largely of type II collagen that matures from a cross-linked heteropolymeric fibril template of types II, IX, and XI collagens. In the articular cartilages of adult joints, type III collagen makes an appearance in varying amounts superimposed on the original collagen fibril network. In a study to understand better the structural role of type III collagen in cartilage, we find that type III collagen molecules with unprocessed N-propeptides are present in the extracellular matrix of adult human and bovine articular cartilages as covalently cross-linked polymers extensively cross-linked to type II collagen. Cross-link analyses revealed that Telopeptides from both N and C termini of type III collagen were linked in the tissue to helical cross-linking sites in type II collagen. Reciprocally, Telopeptides from type II collagen were recovered cross-linked to helical sites in type III collagen. Cross-linked peptides were also identified in which a trifunctional pyridinoline linked both an α1(II) and an α1(III) Telopeptide to the α1(III) helix. This can only have arisen from a cross-link between three different collagen molecules, types II and III in register staggered by 4D from another type III molecule. Type III collagen is known to be prominent at sites of healing and repair in skin and other tissues. The present findings emphasize the role of type III collagen, which is synthesized in mature articular cartilage, as a covalent modifier that may add cohesion to a weakened, existing collagen type II fibril network as part of a chondrocyte healing response to matrix damage.
-
identification of cross linking sites in bovine cartilage type ix collagen reveals an antiparallel type ii type ix molecular relationship and type ix to type ix bonding
Journal of Biological Chemistry, 1992Co-Authors: Jiann Jiu Wu, Patricia E Woods, David R EyreAbstract:Abstract Type IX collagen functions in covalent cross-linkage to type II collagen in cartilage (Eyre, D. R., Apone, S., Wu, J. J., Ericsson, L. H., and Walsh, K. A. (1987) FEBS Lett. 220, 337-341). To understand this molecular relationship better, an analysis of all cross-linking sites labeled by [3H]borohydride was undertaken using the protein prepared from fetal bovine cartilage. Sequence analysis of tryptic peptides containing the 3H-labeled cross-links showed that each of the chains of type IX collagen, alpha 1(IX), alpha 2(IX), and alpha 3(IX), contained a site of cross-linking at the amino terminus of the COL2 triple-helix to which the alpha 1(II)N-Telopeptide could bond. The alpha 3(IX)COL2 domain alone also had an attachment site for the alpha 1(II)C-Telopeptide. The distance between the alpha 1(II)N-Telopeptide and alpha 1(II)C-Telopeptide interaction sites, 137 residues, is equal to the length of the hole zone (0.6D) in a type II collagen fibril. This implies an antiparallel type II to type IX cross-linking relationship. Peptide analysis also revealed an unknown amino acid sequence linked to the COL2 cross-linking domains in both the alpha 1(IX) and alpha 3(IX) chains. Using antibodies to this novel peptide, its origin in the collagen alpha 3(IX)NC1 domain was established. In summary, the results confirm extensive covalent cross-linking between type IX and type II collagen molecules and reveal the existence of type IX-type IX bonding. These data provide a molecular basis for the proposed function of type IX collagen as a critical contributor to the mechanical stability and resistance to swelling of the collagen type II fibril framework of cartilage.
