Fig. 7: EC-specific Dach1 overexpression enhances trabecular bone formation.
From: Specialized post-arterial capillaries facilitate adult bone remodelling
a, Schematic representation of tamoxifen-inducible Dach1 overexpression in Aplnr+ ECs. b, Tile-scan confocal images showing expansion of CAV1 (green, white arrowheads) immunostained arteries and type R capillaries in the Dach1 gain-of-function (Dach1OE) femur relative to littermate control at postnatal day 30 (P30). c, High-magnification confocal images of EMCN (red) and VEGFR3 (green) immunostained femurs showing the expansion of type R capillaries near TB in Dach1OE mutants relative to littermate control. White arrowheads indicate type R capillaries. d, Quantitation of arteries/arterioles and CAV1+ area in control and Dach1OE mutants. n = 3 mice per group. Mean ± s.e.m. P values were obtained by unpaired two-tailed t-test. e, Representative three-dimensional (3D) reconstruction of µCT measurements of P30 Dach1OE and control femoral TB. f, Quantitation of parameters: bone volume/tissue volume (BV/TV), trabecular number represented by number of trabeculae per millimetre, connectivity density (connectivity density per cubic millimetre) and cortical thickness (mm). n = 3 mice per group. Mean ± s.e.m. P values were obtained by an unpaired two-tailed t-test. g, Schematic overview of scRNA-seq workflow for non-haematopoietic cells from Dach1OE and littermate control long bone. h,i, UMAP plots of BMSCs (n = 10,315) with colour-coded subclusters, namely osteoblasts (OBs), osteocytes (OCYs), septoclasts (SCs), proliferating BMSCs (pBMSCs), mpMSCs and dpMSCs (dpMSCs1 and dpMSCs2) (h). UMAP distribution of Dach1OE and control BMSCs, as indicated by colour (i). j, Bar plots showing proportion of cells in Dach1OE and control BMSC subclusters. k, Heatmap showing the top three marker genes for each BMSC subcluster. l, Heatmap illustrating differentially expressed genes in Dach1OE and control BMSCs related to hypoxia, growth factors, adipogenic and osteogenic transcription factors, and regulators of osteogenesis. Texts in red are the areas of interest. Colour bars in k and l illustrate the expression level (log2 fold change). Data in h–l are derived from an integrated scRNA-seq dataset of two conditions.
