Figure 1.

Response of IL6 trans-signaling by tissue-resident cells of articular joint

(A and B) Flow cytometric histogram (A) and quantitative gMFI (B) showing the expression of respective receptors in primary mouse chondrocytes. n = 3 biological replicates. gMFI, geometric mean fluorescence intensity.

(C and D) Experimental design (C) and heatmap (D) showing the secretion of interleukins, chemokines, and matrix enzymes from cartilage explants (n = 3) treated with hyper IL6, sgp130Fc, or their combination at the indicated doses. Each cell of heatmap represents the average expression value of cytokines from three technical replicates. Cytokines were measured using Luminex assay.

(E) Representative TRAP stain images of BMMs (isolated from wild-type, il6st^−/−, and tnsrsf11a^−/− mice) treated with 50 ng/mL hyper IL6 or 100 ng/mL RANKL for 5 days. Scale bars, 500 μm. These micrographs are representative of three biological replicates for each group.

(F) Surface area of TRAP-positive BMMs in (E) was measured using ImageJ software. Each dot represents the pixel size of an identified osteoclast.

(G) Representative TRAP stain images of hyper IL6-induced BMMs treated with DMSO (<0.1%), 20 μg/mL AG490, or 5 μmol/L Stattic. Scale bars, 500 μm. These micrographs are representative of three biological replicates for each group.

(H) Surface area of TRAP-positive BMMs in (G) was measured using ImageJ software. Each dot represents the pixel size of an identified osteoclast.

The data are representative of two (A–D) or three (E–H) independent experiments with biologically independent samples. All data are presented as mean ± SEM. In (F) and (H), statistical significance was calculated using Kruskal-Wallis test with Dunn’s multiple comparisons test.