Fig. 1: Loss of aortic smooth muscle cells (SMCs) occurs in HGPS knock-in mice but not Zmpste24–/– mice.
A Confocal fluorescence microscopy images of the proximal ascending aorta from 16-week-old Lmna+/+, LmnaG609G/G609G, and Zmpste24−/− mice stained with antibodies against smooth muscle actin (Sm-actin, green), collagen type VIII (Col VIII, red), and CD31 (magenta). Nuclei were stained with Dapi (white). Scale bar, 50 µm. Yellow dotted lines mark the borders of the medial layer. Red arrowheads point to areas with reduced Sm-actin staining and reduced numbers of SMC nuclei. The yellow arrowhead points to collagen type VIII staining in the adventitia. Images of the entire tissue sections are shown in Fig. S1A. B Confocal fluorescence microscopy images of the proximal ascending aorta from 13-week-old Lmna+/+ and LmnaG609G/G609G mice and a 21-week-old Zmpste24−/− mouse, all expressing a nuclear-targeted tdTomato transgene, stained with an antibody against farnesyl-prelamin A. The boxed regions are shown at higher magnification in the middle and far-right columns. The images show Dapi (white), elastic fibers (green), tdTomato (tdTom; red), and farnesyl-prelamin A (PreA; magenta). The yellow arrowhead (middle column) points to tdTomato outside of an SMC nucleus. Scale bar, 10 µm. Images of the entire tissue sections are shown in Fig S1B. C Expression of Col8α1 in aortas from 21-week old Lmna+/+, LmnaG609G/+, and Zmpste24−/− mice. Mean ± SEM. The numbers of mice are shown in parentheses. ANOVA. *P < 0.01. Representative microscopy images of sections from the ascending thoracic aorta [stained with Dapi (blue)] from a 21-week-old Zmpste24+/+ mouse (D) and a Zmpste24−/− mouse (E) Scale bar, 100 µm. F Bar graph showing the numbers of nuclei (relative to area) in the proximal ascending thoracic aorta in 21-week-old Zmpste24+/+ (WT) and Zmpste24−/− (ZmpKO) mice. Mean ± SEM (n = 5 mice/group). Student’s t test. P = 0.84. Images of the entire tissue sections used for quantification are shown in Fig. S2.
