Fig. 3
From: NEDD4-1 deficiency impairs satellite cell function during skeletal muscle regeneration
Effect of Nedd4-1 deletion in SCs during early muscle regeneration. A Pax7CreERT2/+; Nedd4-1f/f mice were injected with tamoxifen (TMX) or vehicle (Veh) for five days (see “Materials and methods” section). 48 h after the final dose, myofibers were isolated for further analysis. B Myofibers were isolated from mice treated as in A and maintained in proliferation culture conditions for 24 h. NEDD4-1 expression was analyzed by IF. PAX7 and SYNDECAN-4 (Sdc-4) were used as independent SC markers. Quantification shows average percentage of NEDD4-1(+)/PAX7(+)/SYNDECAN-4(+) cells upon treatment with vehicle (SC-N4wt) or TMX (SC-N4KO); n = 3, ***P-value < 0.001. Scale bar: 10 μm. C Pax7CreERT2/+; Nedd4-1f/f mice were injected with tamoxifen (TMX) or vehicle (Veh) for five days. 48 h after the final dose, TA muscles were injured by BaCl2 intramuscular injection (see “Materials and methods” section). Injured and contra-lateral uninjured TAs were isolated at 9 dpi for further analysis. D Representative image of frozen injured TAs obtained from SC-N4wt and SC-N4KO animals, respectively. Quantification shows normalized TA weight of contra-lateral (uninj.) and injured (inj.) muscles isolated from SC-N4wt (white bars) and SC-N4KO (black bars) animals; n = 3, ***P-value < 0.001. E H&E staining (left panels) of injured and contra-lateral (uninjured) TA cryosections from SC-N4wt and SC-N4KO animals. Dotted lines highlight differences in muscle size/shape. IF staining (right panels) for LAMININ (green) also shows differences in tissue architecture. Arrowheads indicate areas devoid of myofibers/enriched in infiltrating cells. Scale bars: 50 μm. F Sirius red staining of injured (9 dpi) and contra-lateral (uninjured) TA cryosections. Quantification of total Sirius red-stained area shows increased collagen deposition in injured SC-N4KO muscles; n = 3, ***P < 0.001. Scale bar: 200 μm