Fig. 5 | Nature Communications

Fig. 5

From: Macrophage-released ADAMTS1 promotes muscle stem cell activation

Fig. 5

Adamts1 mice have accelerated regeneration when young but a depleted satellite cell pool with aging. ac (left) Images of H&E-stained histological sections prepared from TA muscle injuries that were induced at 1 a, 4 b and 8 c months of age in Wt and Tg mice (mice were sacrificed 5 days post injury for the 1- and 4 month-old mice and 7 days post injury for the 8-month-old mice). Scale bar = 50 μm. ac (right) Quantification of the cross-sectional myofiber diameters post injury calculated for a 1-month-old (Wt: n = 6; Tg: n = 3), b 4-month-old (Wt: n = 4; Tg: n = 4) and c 8-month-old (Wt: n = 3; Tg: n = 3) mice. The numbers of myofibers counted is displayed in the frequency axis. The 1-month-old Tg mice had accelerated regeneration compared to Wt littermates (P < 0.0001). The 8-month-old Tg mice had impaired regeneration compared to Wt littermates (P < 0.0001). d, e (left) Flow cytometry plots of CD45−/CD31−/Scal1−/Vcam+ satellite cells in Tg and Wt mice at d 1 and e 4 months of age. d, e (right) Quantification of the number of satellite cells per total live mononuclear cells isolated (~ 5×105 cells from each animal were analyzed) from the hind limb muscles of 1-month-old (Wt: n = 11; Tg: n = 10) and 4-month-old (Wt: n = 11; Tg: n = 9) mice showing a depletion of satellite cells in Tg mice (**P < 0.01 at 1 month; ***P < 0.001 at 4 months). f (left) Images from IHC of histological sections of TA muscles isolated from 4-month old Wt and Tg mice and stained for Pax7 (red), Dystrophin (white) and DAPI (blue). Scale bar = 100 μm. f (right) Quantification of the number of Pax7-positive satellite cells per myofiber show Tg mice have fewer satellite cells than Wt mice (n = 3 for each genotype; >200 myofibers per mouse were examined). **P < 0.01. g, Quantification of the number of Pax7-positive cells on freshly isolated myofibers from 4-month-old mice (each point represents a myofiber, n = 3 mice for each genotype) demonstrated that Tg mice have fewer satellite cells. ***P < 0.001. Error bars represent s.d. Statistical significance tested using χ2 for myofiber diameters and paired t-tests for other comparisons

Back to article page