Fig. 6: CD31hiEmcnhi vessels and skeletal progenitors expand and infiltrate into subcritical-sized defects during healing.
From: Quantitative 3D imaging of the cranial microvascular environment at single-cell resolution
A–H Blood vessels (A–H), Osterix+ progenitors (A–D, A'–D'), and Gli1+ progenitors (E–H, E'–H') inside and around 1-mm parietal bone defects at PFD21 (A, B, E, F) and PFD56 (C, D, G, H). The dotted circle marks the defect region. I, J Expansion of Osterix+ and Gli1+ progenitors in the periosteum (yellow arrows) nearby the defect region (dotted lines) and sutures (yellow arrowheads) at PFD21. Progenitors were sparsely populated in the dura mater—the only portion of the calvarium that remained intact following defect injury. Results were replicated in 3 calvaria for each timepoint and staining combination (12 total calvaria). K Spatial relationship of skeletal progenitors to different vessel phenotypes at PFD21 and PFD56 (n = 3). L–N Fractional vessel phenotype volume (L), skeletal progenitor number (M), and total vessel volume (N) in the defect at PFD21 and PFD56 (n = 6 for L, N; n = 3 for M). O MicroCT quantification of defect to contralateral bone volume ratio at PFD21 and PFD56 (n = 4). Data are mean ± SD. Statistics were performed using a two-way ANOVA with Bonferroni post-hoc test (K–M) or two-tailed t-test (N–O). ***p < 0.001, **p < 0.01, *p < 0.05 where designated or between CD31hiEmcnhi and CD31hiEmcn− vessels in K; +++p < 0.001 between CD31loEmcnhi and CD31hiEmcn− vessels. Exact p-values for two-tailed t-tests: N p = 0.0094, O p = 0.5660. Scale bars: 500 μm (I, J); 300 μm (A, C, E, G); 200 μm (B, D, F, H). Colors: Red: Endomucin (Emcn), Gray: Osterix (A–D, I, J) or Gli1 (E–H), Green: CD31.
