Binding sites of human galectins in OA cartilage. (a): OA cartilage from five donors was histologically processed and stained with labeled Gal-1 and Gal-3, respectively. Positivity of chondrons and interterritorial matrix was assessed microscopically for MS ≥9 and MS ≤4 regions separately. The percentages given at the bottom of the table refer to the fractions of specimens presenting stained chondrons or interterritorial matrix among all analyzed OA cartilage specimens (n = 5). − no staining; + moderate staining; ++ intense staining; MS: Mankin score (b, c): Gal-1 staining: reactivity included the matrix of MS ≤4 (b) and MS ≥9 (c) regions of OA cartilage. Insets show negativity of chondrons. (d, e): Gal-3 staining: In MS ≤4 regions (d), no staining of chondrocytes and matrix, whereas in MS ≥9 regions (e) reactivity for both chondrons and matrix was observed. Bars in inserts of ( b-e ): 50μm. Gal-1, galectin-1, Gal-3, galectin-3, OA, osteoarthritis.