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Bay-Jensen A.C.,Cartilage Biology and Biomarkers | Leeming D.J.,Fibrosis Biology and Biomarkers | Kleyer A.,Friedrich - Alexander - University, Erlangen - Nuremberg | Veidal S.S.,Fibrosis Biology and Biomarkers | And 2 more authors.
Rheumatology International | Year: 2012

Ankylosing spondylitis (AS) is characterized by gradual cementation of the vertebrae, a process that is described by excessive extracellular matrix remodeling. Specific matrix metalloproteinase (MMP)-derived collagen fragments are released to the circulation, and measurement of those might act as biomarkers of ankylosis. The aim of the study was to investigate the diagnostic value of five novel assays measuring different collagen species. Five newly developed ELISAs measuring MMP-degraded collagen fragments in serum of 40 AS patients and 40 agematched controls were measured: collagen type I (C1M), type II (C2M), type III (C3M), type IV (C4M) and type VI (C6M) as well as the bone formation marker osteocalcin. The levels of the five collagen neoepitopes were significantly higher in AS patients, except for osteocalcin. Cartilage degradation (C2M) was only significantly correlated with the basement membrane (C4M) in the AS patients. In contrast, C3M was significantly correlated with all of the other collagen markers. The highest diagnostic value was achieved when combining the C2M, C3M and C6M markers, AUC 87% (P < 0.0001). Moreover, a combination of the markers correlated with the clinical mSASS score (P = 0.004, R = 0.44). Novel and unique biomarkers of tissue remodeling may provide diagnostic value and aid in understanding of the AS pathology. Each of the biomarkers tells a unique story, and by combining them in a panel there, we found a strong correlation with mSASSS. We speculate that such panel will be a valuable tool for monitoring patients as effect of treatment, for the prediction of responders and for diagnostic purposes. © Springer-Verlag 2011.

Madsen S.H.,Cartilage Biology and Biomarkers | Andreassen K.V.,Bone Biology | Christensen S.T.,Copenhagen University | Karsdal M.A.,Cartilage Biology and Biomarkers | And 3 more authors.
Steroids | Year: 2011

Introduction: Glucocorticoids are known to attenuate bone formation in vivo leading to decreased bone volume and increased risk of fractures, whereas effects on the joint tissue are less characterized. However, glucocorticoids appear to have a reducing effect on inflammation and pain in osteoarthritis. This study aimed at characterizing the effect of glucocorticoids on chondrocytes, osteoclasts, and osteoblasts. Experimental: We used four model systems to investigate how glucocorticoids affect the cells of the joint; two intact tissues (femoral head- and cartilage-explants), and two separate cell cultures of osteoblasts (2T3-pre-osteoblasts) and osteoclasts (CD14 +-monocytes). The model systems were cultured in the presence of two glucocorticoids; prednisolone or dexamethasone. To induce anabolic and catabolic conditions, cultures were activated by insulin-like growth factor I/bone morphogenetic protein 2 and oncostatin M/tumor necrosis factor-α, respectively. Histology and markers of bone- and cartilage-turnover were used to evaluate effects of glucocorticoid treatment. Results: Prednisolone treatment decreased collagen type-II degradation in immature cartilage, whereas glucocorticoids did not affect collagen type-II in mature cartilage. Glucocorticoids had an anti-catabolic effect on catabolic-activated cartilage from a bovine stifle joint and murine femoral heads. Glucocorticoids decreased viability of all bone cells, leading to a reduction in osteoclastogenesis and bone resorption; however, bone morphogenetic protein 2-stimulated osteoblasts increased bone formation, as opposed to non-stimulated osteoblasts. Conclusions: Using highly robust in vitro models of bone and cartilage turnover, we suggest that effects of glucocorticoids highly depend on the activation and differential stage of the cell targeted in the joint. Present data indicated that glucocorticoid treatment may be beneficial for articular cartilage, although detrimental effects on bone should be taken into account. © 2011 Elsevier Inc. All rights reserved.

Chen-An P.,Cartilage Biology and Biomarkers | Andreassen K.V.,Bone Biology and Pharmacology | Henriksen K.,Bone Biology and Pharmacology | Li Y.,Orthopedic Surgery Unit | And 2 more authors.
PLoS ONE | Year: 2012

Objective: Salmon calcitonin has chondroprotective effect both in vitro and in vivo, and is therefore being tested as a candidate drug for cartilage degenerative diseases. Recent studies have indicated that different chondrocyte phenotypes may express the calcitonin receptor (CTR) differentially. We tested for the presence of the CTR in chondrocytes from tri-iodothyronin (T3)-induced bovine articular cartilage explants. Moreover, investigated the effects of human and salmon calcitonin on the explants. Methods: Early chondrocyte hypertrophy was induced in bovine articular cartilage explants by stimulation over four days with 20 ng/mL T3. The degree of hypertrophy was investigated by molecular markers of hypertrophy (ALP, IHH, COLX and MMP13), by biochemical markers of cartilage turnover (C2M, P2NP and AGNxII) and histology. The expression of the CTR was detected by qPCR and immunohistochemistry. T3-induced explants were treated with salmon or human calcitonin. Calcitonin down-stream signaling was measured by levels of cAMP, and by the molecular markers. Results: Compared with untreated control explants, T3 induction increased expression of the hypertrophic markers (p<0.05), of cartilage turnover (p<0.05), and of CTR (p<0.01). Salmon, but not human, calcitonin induced cAMP release (p<0.001). Salmon calcitonin also inhibited expression of markers of hypertrophy and cartilage turnover (p<0.05). Conclusions: T3 induced early hypertrophy of chondrocytes, which showed an elevated expression of the CTR and was thus a target for salmon calcitonin. Molecular marker levels indicated salmon, but not human, calcitonin protected the cartilage from hypertrophy. These results confirm that salmon calcitonin is able to modulate the CTR and thus have chondroprotective effects. © 2012 Chen-An et al.

Chen-An P.,Cartilage Biology and Biomarkers | Andreassen K.V.,Bone Biology and Pharmacology | Henriksen K.,Bone Biology and Pharmacology | Karsdal M.A.,Cartilage Biology and Biomarkers | Bay-Jensen A.-C.,Cartilage Biology and Biomarkers
Rheumatology International | Year: 2013

Articular cartilage deterioration, which includes cartilage degradation and chondrocyte hypertrophy, is a hallmark of degenerative joint diseases (DJD). Chondrocyte hypertrophy is initiated in the deep layer of the cartilage; thus, a robust explants model for investigation of hypertrophy should include this zone. The aim of this study was to characterize and investigate the hypertrophy-promoting potential of different endogenous factors on an ex vivo articular cartilage model. The full-depth cartilage explants were harvested from bovine femoral condyle and cultured for 13 days in different conditions: 10 ng/ml oncostatin M + 20 ng/ml TNF-α; 100 ng/ml IGF1; 10-100 ng/ml bFGF; 10-100 ng/ml BMP2; 50 μg/ml ascorbic acid in combination with 10 mM β-glycerophosphate; and 20-100 ng/ml triiodothyronine. The cellular activity and morphology, degradation, formation and calcification, and expression level of hypertrophic markers were investigated. The hypertrophic factors tested all induced cellular activity and marked morphological changes starting at day 4, however, not in a synchronized manner. Both cartilage degradation and formation were induced by T3 (P < 0.05). Only T3 had a full hypertrophic gene expression profile (P < 0.05). We developed and characterized a novel model for investigation of chondrocyte hypertrophy. We speculated that this can become an important investigatory tool for investigation of matrix turnover, chondrocyte hypertrophy and cartilage calcification that are associated with DJD pathogenesis. © 2012 Springer-Verlag.

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