Advanced glycation end products cause collagen II reduction by activating Janus kinase/signal transducer and activator of transcription 3 pathway in porcine chondrocytes

• Published in: Rheumatology (Oxford, England) Vol. 50; no. 8; pp. 1379 - 1389
• Main Authors: Huang, Chuan-Yueh, Lai, Kuan-Yui, Hung, Li-Feng, Wu, Wan-Lin, Liu, Feng-Cheng, Ho, Ling-Jun
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.08.2011
• Subjects: ADAM Proteins - genetics; ADAM Proteins - metabolism; Advanced glycosylation end products; aggrecan; Aggrecans - metabolism; Animals; Biological and medical sciences; Cartilage diseases; Cells, Cultured; Chondrocytes; Chondrocytes - drug effects; Chondrocytes - metabolism; Collagen (type II); Collagen Type II - metabolism; Collagenase 3; Diseases of the osteoarticular system; Disintegrins - genetics; Disintegrins - metabolism; Drugs; Electrophoretic mobility; Enzymes; Female; Gene expression; Gene Expression - drug effects; Gene Knockdown Techniques; Gene Silencing; Glycation End Products, Advanced - pharmacology; Histochemistry; Immunoblotting; Janus kinase 2; Janus kinase 3; Janus Kinases - antagonists & inhibitors; Janus Kinases - genetics; Janus Kinases - metabolism; Matrix Metalloproteinase 13 - drug effects; Matrix Metalloproteinase 13 - genetics; Matrix Metalloproteinase 13 - metabolism; Medical sciences; Miscellaneous. Osteoarticular involvement in other diseases; Osteoarthritis; Osteoarthritis - drug therapy; Osteoarthritis - genetics; Osteoarthritis - metabolism; Phosphorylation; Proteoglycans; RNA, Small Interfering - genetics; Signal Transduction - drug effects; Signal Transduction - genetics; Stat3 protein; STAT3 Transcription Factor - antagonists & inhibitors; STAT3 Transcription Factor - genetics; STAT3 Transcription Factor - metabolism; Swine; Transcription; JAK/STAT3; Advanced glycation end products; Collagen II; Osteoarthritis; Ageing; Chondrocytes; Chondrocyte; Transcription; Enzyme; Transferases; Diseases of the osteoarticular system; Rheumatology; Glycation; Pig; Transducer; Vertebrata; Mammalia; Kinase; Collagen; Transcription factor STAT3; Arthropathy; Degenerative disease; Artiodactyla; Ungulata
• DOI: 10.1093/rheumatology/ker134
• ISSN: 1462-0324

Objectives. The major risk factor for OA is ageing; however, the mechanisms remain largely unclear. We investigated the effects and mechanisms of advanced glycation end products (AGEs) that accumulate in aged joints in chondrocytes. Methods. Porcine chondrocytes or cartilage fragments were prepared. Gene expression of MMPs and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) was assessed by real-time RT-PCR. Gelatin zymography was used to determine MMP-13 enzyme activity. Histochemistry or immunoblotting analysis was applied to determine the expression of collagen II, proteoglycan and aggrecan. Electrophoretic mobility shift assay and immunoblotting were used to study the activation of signal transducer and activator of transcription 3 (STAT3). Genetic manipulations with short hairpin RNA (shRNA) or dominant negative constructs were applied. Results. AGE enhanced expression and enzyme activity of MMP and ADAMTS genes and resulted in reduction of collagen II. Both janus kinase 2 (JAK2) and JAK3 inhibitors suppressed AGE-induced MMP-13, ADAMTS-4 and ADAMTS-5 expression and enzyme activity. Inhibition of JAK2 or JAK3 prevented AGE-mediated decrease of collagen II in chondrocytes and proteoglycan (aggrecan) degradation in cartilage fragments. In addition, interference of STAT3 expression inhibited AGE-induced MMP-13 and ADAMTS enzyme activities and mRNA levels. Furthermore, expression of the dominant negative receptor of AGE (DN-RAGE) blocked AGE-induced STAT3 phosphorylation. Conclusion. Blocking JAK/STAT3 signalling pathway inhibited AGE-induced activation of MMP-13 and ADAMTS and prevented AGE-mediated decrease of collagen II and proteoglycan (aggrecan). The results indicated that JAK/STAT3 pathway may be a potential target for designing disease-modifying drugs for the treatment of OA.