Fig. 6.

Sickle cardiomyocytes exhibit hypoxia/ischemia-related mitochondrial ultrastructural changes, contracted sarcomeres, and chaotic remodeling. Representative EM images of WT and sickle mouse LV posterior wall myocardium. Compared with WT control (A and C), a subset of cardiomyocytes in an 8-mo-old sickle mouse show ultrastructural abnormalities (B, D, and E). Electron lucent areas between mitochondria and sarcomeres, and membranes of the SR and sarcomeres are noted (B, arrows). Mitochondria are hypertrophied, more abundant, more rounded, with less densely packed and often disrupted cristae (D, arrow). Sarcomeres in some of the sickle cells were contracted and hence shorter in diastole (D, double-headed arrow) compared with WT (C, double-headed arrow). Chaotic cardiomyocyte remodeling is noted in a 2-mo-old Berk-SS mouse (E). Sarcomere lengths of two, 8-mo-old sickle (Berk-SS) and age- and gender-matched WT controls are shown in F. Data shown as mean ± SEM, n = 187 sarcomere in WT and 150 sarcomere in Berk-SS, two mice per group, Mann–Whitney U test, ****P ≤ 0.0001.