@article {Gu{\'e}vremont636, author = {M Gu{\'e}vremont and J Martel-Pelletier and C Boileau and F-T Liu and M Richard and J-C Fernandes and J-P Pelletier and P Reboul}, title = {Galectin-3 surface expression on human adult chondrocytes: a potential substrate for collagenase-3}, volume = {63}, number = {6}, pages = {636--643}, year = {2004}, doi = {10.1136/ard.2003.007229}, publisher = {BMJ Publishing Group Ltd}, abstract = {Background: Galectin-3 is a lectin detected in mature and early hypertrophic chondrocytes; osteoarthritic (OA) chondrocytes can re-express hypertrophic markers. Objective: To investigate the synthesis and subcellular localisation of galectin-3 in adult chondrocytes as well as the possibility of cleavage of galectin-3 by collagenase-1 and -3. Methods: Galectin-3 was assessed by immunohistochemistry and real time polymerase chain reaction (PCR) in normal and OA cartilage. Its localisation was investigated by subcellular fractionation, immunocytology, and flow cytometry. Proteolysis of galectin-3 by collagenase-1 and -3 was determined by in vitro assay. Results: Galectin-3 expression was increased 2.4-fold as measured by reverse transcriptase (RT)-PCR (p\<0.05, n = 5) and threefold by immunohistochemistry (p\<0.003 n = 6) in OA cartilage compared with normal cartilage. In adult chondrocytes, galectin-3 was found in the cytosol and membrane enriched fractions. Both immunocytology and flow cytometry confirmed the presence of galectin-3 at the surface of chondrocytes. A strong correlation was found between integrin-β1 and galectin-3 expression at the surface of chondrocytes. Moreover, collagenase-3 cleaved galectin-3 with a higher activity than collagenase-1. The proteolysed sites generated were identical to those produced by gelatinases A and B. Conclusion: Galectin-3 may play a part in OA, having two roles, one intracellular and not yet identified, and another at the cell surface, possibly related to the interaction of chondrocytes and the cartilage matrix.}, issn = {0003-4967}, URL = {https://ard.bmj.com/content/63/6/636}, eprint = {https://ard.bmj.com/content/63/6/636.full.pdf}, journal = {Annals of the Rheumatic Diseases} }