Fig. 4: PZ clears senescent bone marrow (BM) stromal cells to improve osteoprogenitor functions.

a–f Expression of Cdkn1a (a), Cxcl12 (b), Mmp13 (c), Tnfsf11 (d) and Il1α (e) mRNA in BM stromal cells from young (Young) or naturally aged mice treated with vehicle (VEH), ABT263 (ABT) or PZ as illustrated in Fig. 3b was measured by quantitative PCR (qPCR). f, g. Analysis of senescent cells (SCs) in BM stromal cells from young (Young) and naturally aged mice treated with VEH, ABT, or PZ by senescence-associated β-galacotosidase (SA-β-gal) staining. Representative staining images (left) and percentage of SA-β-gal positive cells (right) are presented. h, i Analysis of osteoblastogenesis of BM stromal cells from young (Young) and naturally aged mice treated with VEH, ABT or PZ by Alizarin Red staining. Representative staining images (left) and quantification of Alizarin Red staining in the cells (right) are presented. j, k. Analysis of adipogenesis of BM stromal cells from young (Young) or naturally aged mice treated with VEH, ABT or PZ by Oil Red O staining. Representative staining images (left) and quantification of Oil Red O staining in the cells (right) are presented. l, m. Analysis of osteoclastogenesis of BM myeloid cells from young (Young) or naturally aged mice treated with VEH, ABT, or PZ by tartrate-resistant acid phosphatase (TRAP) staining. Representative images (left) and quantification of TRAP-positive multinucleated osteoclasts (right) are presented. The data are presented as mean ± SEM (a–e, n = 3 independent assays; g, n = 5 independent assays; i, k, and m, n = 4 independent assays; each assay using a sample pooled from 2 to 3 mice from the same experimental group). a, b, c p < 0.05 vs. Young, Aged + VEH, and Aged + ABT, respectively, determined by one-way ANOVA with Tukey’s post-hoc tests. Scale bars for f, h, j, and l are 50 µm, 1 cm, 50 µm, and 500 µm, respectively. Source data are provided as a Source Data file. The exact P values are provided in the Source Data file.