Fig. 2: Loss of TGFβ signaling suppresses inflammatory osteoclastogenesis and bone resorption. | Nature Communications

Fig. 2: Loss of TGFβ signaling suppresses inflammatory osteoclastogenesis and bone resorption.

From: TGFβ reprograms TNF stimulation of macrophages towards a non-canonical pathway driving inflammatory osteoclastogenesis

Fig. 2

a Osteoclast differentiation using BMMs derived from WT and Tgfbr2ΔM mice was stimulated with RANKL for 3 days. Left: TRAP staining. Right: relative area of TRAP-positive-MNCs (≥3 nuclei/cell) per well. TRAP-positive cells: red. (n = 5/group). b, c μCT images (b) and bone morphometric analysis (c) of trabecular bone of the distal femurs isolated from the indicated 12-week-old-male littermate mice (n = 5/group). d, e Osteoclast differentiation determined by TRAP staining (d, left) and the relative area of TRAP-positive MNCs per well (d, right), and qPCR analysis of mRNA expression of Ctsk, Acp5, and Dcstamp (e) in the cell cultures, in which the bone marrow of WT and Tgfbr2ΔM mice was primed with or without TGFβ for 4 days, followed by TNF stimulation for 3 days. TRAP-positive cells: red. d, e: n = 5/group. f–h μCT images (f, left), the quantification of the resorption area (f, right), TRAP staining of bone surface (g, left) and histological sections (g, right), and histomorphometric analysis of the slices of the calvarial bones obtained from 12-week-old-male WT and Tgfbr2ΔM mice after PBS or TNF injection to the calvarial periosteum daily for 5 days (n = 8/group in f, n = 6/group in h). i–k μCT images of the surface of tarsal joints (red arrows: bone erosion) (i), TRAP staining (j) and histomorphometric analysis (k) of the tarsal joint sections obtained from the indicated 12-week-old female mice with PBS injection as the control or the littermate female mice that developed K/BxN serum-induced arthritis (n = 6/group). BV/TV, bone volume per tissue volume; BMD, bone mineral density; Tb.N, trabecular number; Tb.Sp, trabecular separation; Tb.Th, trabecular thickness; ES/BS, erosion surface/bone surface; Oc.S/BS, osteoclast surface/bone surface; N.Oc/B.Pm, number of osteoclasts per bone perimeter. a, c ns: not statistically significant by two-sided Student’s t test. d, e, f, h, k **p < 0.01; ***p < 0.001; ****p < 0.0001; ns: not statistically significant by two-way ANOVA with Bonferroni’s multiple comparisons test. Error bars: a, c–f, h, k Data are mean ± SD. Scale bars: a, d, j 200 µm; b, g 100 µm; f, i 1.0 mm. Source data are provided as a Source Data file.

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