Fig. 1

The effect of the JAK inhibitor on bone erosion, periarticular osteopenia and systemic bone loss in autoimmune arthritis. A Arthritis score of the CIA mice (n = 4) and CIA mice administered the JAK inhibitor upadacitinib (CIA + JAKi mice) (n = 6). The JAK inhibitor was administrated 1 week after the secondary immunization. B Representative μCT images (upper: knee joint, lower: calcaneocuboid joint), eroded surface (left) and eroded volume (right) per bone surface of the calcaneocuboid joint of untreated (n = 4), CIA (n = 4) and CIA + JAKi mice (n = 6). The red area indicates cavities. C Representative μCT images (upper panel), bone volume per tissue volume (BV/TV) (lower left) and trabecular thickness (lower right) of the distal femur of untreated (n = 4), CIA (n = 4), and CIA + JAKi mice (n = 6). D Representative μCT images (upper panel), BV/TV (lower left) and trabecular thickness (lower right) of lumbar vertebrae of untreated (n = 4), CIA (n = 4) and CIA + JAKi mice (n = 6). Scale bar: (1 mm) (B, C, D). All data are expressed as the mean ± SEM. *P < 0.05; **P < 0.01; ***P < 0.001; ****p < 0.0001; by unpaired Student’s t test (A), and one-way ANOVA with the Holm-Sidak multiple comparisons test (B–D)