Related Experiment Video
Updated: Jul 29, 2026

A 3D System for Culturing Human Articular Chondrocytes in Synovial Fluid
Published on: January 31, 2012
Galectin-3 surface expression on human adult chondrocytes: a potential substrate for collagenase-3
M Guévremont1, J Martel-Pelletier, C Boileau
1Unité de Recherche en Arthrose, Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada.
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-beta1 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.
Related Concept Videos
Structural Protein Function
Collagen, the most abundant protein in mammals, is found throughout the body. In connective tissue, such as skin, ligaments, and tendons, it provides tensile strength and elasticity. In bones and teeth, it mineralizes to form...
Proteoglycans
Glycosaminoglycans
GAGS are found in the extracellular matrix of vertebrates, invertebrates, and bacteria. Due to their polar nature they attract water, and serve as excellent lubricants or shock absorbers in an animal body.
Hyaluronic...
Fibril-associated Collagen
For example, the type II collagen fibrils in cartilage have covalently bound type IX fibril-associated collagens at regular intervals. Other types of fibril-associated collagens are...
Matrix Proteoglycans and Glycoproteins
Type IV Collagen of Basal Lamina
A type IV collagen molecule has six alpha chains which can exist in...

