Figure 7. NM ruptures are frequent in aortic SMCs but absent in cardiomyocytes and hepatocytes of Lmna^G609G/G609G mice.

(A) Fluorescence microscopy images of cross sections (10 μm–thick) of the ascending aorta from 3 8-week-old Lmna^+/+ (top row) and 3 8-week-old Lmna^G609G/G609G (bottom row) mice expressing the Nuc-tdTomato transgene. The mouse IDs are shown in the bottom left-hand corner of each image. Nuc-tdTomato (orange); DAPI (blue). Scale bar: 100 μm. (B) Quantification of NM ruptures in SMCs and endothelial cells (EC) in the ascending aorta of 8-week-old Lmna^+/+ and Lmna^G609G/G609G mice. The number of NM ruptures is reported as a percentage of total nuclei examined in individual cross sections (A) (mean ± SEM; Student’s t test; *P < 0.001). The total number of nuclei scored is shown in parentheses. (C) Quantification of NM ruptures in SMCs in the upper and lower descending aorta of 3 8-week-old Lmna^+/+ and Lmna^G609G/G609G mice. The number of NM ruptures is reported as a percentage of total nuclei examined in individual cross sections (see Supplemental Figure 6C) (mean ± SEM; Student’s t test; *P < 0.001). The total number of nuclei scored is shown in parentheses. (D) Confocal fluorescence microscopy images of the ascending aorta, heart, and liver from an 8-week-old Lmna^G609G/G609G mouse. The colored images show DAPI (blue), elastic fibers (green), and Nuc-tdTomato (orange). To assist in visualizing the boundaries of nuclei, the DAPI stain is shown in white (bottom row). The yellow arrow points to Nuc-tdTomato outside of a nucleus in an aortic SMC. Scale bar: 10 μm.