Fig. 1: Aged bone marrow causes senescence propagation in multiple young organs.
a, Experimental setup for bone marrow transplantation. Young recipients (3 months old, male mice) were lethally irradiated and then transplanted with bone marrow from young donors (3 months old, male mice) and aged donors (24 months old, male mice). b, The mRNA levels of senescence-associated genes and SASP factors in liver, muscle and adipose tissue of young recipients receiving bone marrow transplantation (YBMT and ABMT) (n = 4 mice for ABMT; n = 3 mice for other groups). c, Western blot analysis of p53, p21 and γH2A.X protein expression in liver (left) and quantitative analysis (right) (n = 3 mice). d, Immunofluorescence detection of γH2A.X in femur and brain (scale bar, 50 μm; n = 5 mice) (left) and quantitative analysis (right). e, GTT and ITT (n = 5 mice). f, Western blot analysis of phosphorylated key molecules of insulin pathway in the liver (left) and quantitative data (right) (n = 3 mice). g, Representative µCT images of recipient mice after transplantation (left) and quantitative analysis of trabecular bone volume/tissue volume (BV/TV) (right) (n = 5 mice). h, Old mice (16 months old, male) were treated with vehicle or D+Q for 5 months. After 5 months, bone marrow was isolated from mice and transplanted into young mice (3 months old, male) (ABMT and DQ-ABMT). Western blot analysis of p21 and γH2A.X protein expression in liver (n = 4 mice for ABMT; n = 3 mice for other groups) and adipose tissue (n = 6 mice for ABMT; n = 5 mice for other groups) (left) of young recipients receiving bone marrow from DQ-treated aged mice, and quantitative analysis (right). i,j, Representative images of SA-β-gal staining in the adipose tissue (i) and femur (j) (scale bar, 50 μm; n = 5 mice) (left), and their quantitative analysis (right). The red arrows represent the SA-β-gal-positive cells. k,l, GTT (k) and ITT (l) were performed on young recipients after transplantation (n = 6 mice). m, Representative µCT images (left) and quantitative analysis (right) (n = 6 mice). The colored shading in e, k and l represents the area under the curve. n, Hanging endurance (n = 6 mice). o, Novel object recognition (n = 6 mice). Data are presented as mean ± s.e.m. *P < 0.05, **P < 0.01 and ***P < 0.001, as determined by one-way ANOVA followed by Tukey’s multiple comparison test. BM, bone marrow; FDR, false discovery rate; I.V., intravenous; mo, months; Rel. fold, relative fold; T.Ar, total area.
