Figure 3

Immuno-localization of the CTR in human chondrocytes. (A) Human OA cartilage tissue, upper zone (obj. 20×). The square indicated the area of interest of the upper zone. (B) Clonal chondrocytes (clusters) positive for the CTR (obj. 40×). (C) Singular chondrocytes of the upper zone positive for the CTR (obj. 40×). (D) Overview picture of the deep zone with the tidemark marked in light pink (obj. 20×). (E) Close up of a column chondrocytes of the deep zone (obj. 100×). (F) Close up of a hypertrophic chondrocytes in the deep zone with positive staining in the fragmentized nucleus (obj. 100×). (G)-(I) Positive CTR staining in the cell membrane of primary chondrocytes of three different patients (obj. 100×). (J) Negative control: No staining is shown when omitting the primary antibody in the experimental protocol (obj. 100×). (K) Positive control: A differentiated osteoclast resorbing on bone shows the expected staining of the basolateral membrane where the receptor is expressed (obj. 100×). (L) Negative staining in synovial membrane (obj. 20×). Antibody staining: Acris sp1338p (red-brown) and positive staining is indicated with arrows. Cell nucleus was counter stained with Mayer's hematoxylin (blue).