Fig. 8: Inflammatory cytokines exacerbate the pro-inflammatory response in bone marrow macrophages.

a, b Representative Western blots (a) and corresponding quantification (b) showing the expression of NFATc1 (n = 3), NF-κB p65 (n = 4), and CTSK (n = 3) in BMMs isolated from matured adults (6 months) or young (3 months) mice with or without the presence of recombinant murine IL-1β or its neutralizing antibody. c, d The gene expression of pain-associated cytokines (c) and other pro/anti-inflammatory cytokines (d) in BMMs from young or matured adult mice with or without the addition of recombinant murine IL-1β or its neutralizing antibody (n = 3). e The effects of various inflammatory cytokines on the gene expression of IL-1R1, MMP9, CTSK, and NOS2 (n = 3). f Schematic diagram showing SARS-CoV-2 infection-induced cytokine dysregulation leads to an amplified and broadened pro-inflammatory cascade in the skeletal tissue, resulting in pathological bone resorption. Data were mean ± SD. ns: P > 0.05, *P < 0.05, **P < 0.01 by two-way ANOVA with Bonferroni’s post hoc test.