Glucosamine altered the expression of bone resorption and bone remodeling markers in the CIOA joints. Joints of healthy mice, CIOA mice treated with PBS (CIOA) and CIOA mice treated with glucosamine hydrochloride (CIOA + Glu1) were fixed, decalcified, dehydrated and embedded in paraffin. The sections (n = 10/mice) were stained with antibodies against RANKL, BMP-2, TGF-β3, pSMAD-2 and DKK-1. The specific staining was detected using a peroxidase-DAB staining kit. The positive staining for RANKL in the joints (a), BMP-2 in osteophyte areas (b) and TGF-β3 (c), pSMAD-2 (d) and DKK-1 (e) in cartilage of CIOA mice untreated or treated with glucosamine was indicated with arrows; magnification × 100.