Fig. 5. MMP13 inhibition significantly increases SMC number in aortic arch of Lmna^G609G/G609G mice.

a Schematic representation of the animal protocol. WtWt, KiWt, KiHt, and KiKo mice (age: 10 weeks) were evaluated. b Quantification of MMP13 activity (plasma from WtWt, n = 9, and KiWt, n = 6, mice) by ELISA. Fluorescence signal was normalized by mice weight. Statistical analyses were performed by a two-tailed unpaired Student’s t test. c Immunofluorescence analyses in the aortic arch for α-SMA, progerin, and heparan sulfate (HS). Cell nuclei were stained with DAPI. Scale bar is 100 µm for α-SMA staining and 50 µm for progerin and heparan sulfate staining. For α-SMA staining, n = 5 animals, except for KiHt (four animals). For progerin staining, n = 5 animals, except for KiHt (three animals). For heparan sulfate n = 6 WtWt, n = 6 KiWt, n = 4 KiHt, and n = 5 for KiKo. d Heart rates in mice (n = 8 WtWt, n = 6 KiWt, n = 7 KiHt, and n = 5 KiKo). Statistical analyses were performed by one-way ANOVA followed by Newman–Keuls’s post test. e Number of SMC nuclei in aortic arch per tissue area (mm²) (n = 2–3 slides examined over five animals, except for KiHt (four animals)). Statistical analyses were performed by a two-tailed unpaired Student’s t test. f Percentage of progerin-positive cells in SMCs. n = 5 animals, except for KiHt (three animals). Statistical analyses were performed by one-way ANOVA followed by Newman–Keuls’s post test. g Expression of heparan sulfate as evaluated by immunofluorescence. Intensity of heparan sulfate was calculated in each picture (at least 16 pictures per condition) and normalized by cell number mice (n = 6 WtWt, n = 6 KiWt, n = 4, KiHt and n = 5 KiKo). In b, d–g, results are mean ± SEM. *, **, ***, **** denote statistical significance (p < 0.05, p < 0.01, p < 0.001, p < 0.0001).