Figure 3

Large-scale electron microscopy indicated increased intracellular stress, decreased elastin lamella and attenuated cell adhesion in Myh11^∆K/∆K aortas. (A) Electron microscopy images of WT and Myh11^∆K/∆K+ descending aortas. Myh11^∆K/∆K nuclei included thinner nuclear envelope and many granular components (upper row, scale bars = 1 µm, × 10,000). The adhesive faces between SMCs in Myh11^∆K/∆K+ aortas were shorter than those in WT (middle row, scale bars = 1 µm, × 12,000). The size of the SMCs in the Myh11^∆K/∆K+ aortas were larger than those in WT (bottom row, scale bars = 10 µm, × 2,000). (B) Debris was occasionally found in the Myh11^∆K/∆K aortas (scale bars = 1 µm, × 10,000). (C) Myelin figures were present inside or outside Myh11^∆K/∆K SMCs [scale bars = 1 µm, × 12,000 (left), × 20,000 (right)]. (D) The adhesive length of the SMCs in the Myh11^∆K/∆K aorta was significantly shorter than that in WT [n = 45 (15 cells per an aortic sample), WT 12.50 ± 8.16 µm/cell vs Myh11^∆K/∆K 7.28 ± 4.66 µm/cell, p < 0.01). (E) The area ratio of the elastic lamellae in the 50-µm section was decreased in MYH11^∆K/∆K aortas compared to that in WT [n = 45 (15 of 50-µm sections per an aortic sample), WT 0.29 ± 0.04 vs Myh11^∆K/∆K 0.23 ± 0.02, p < 0.01]. ** p < 0.01, Mann–Whitney U test.