Acute Myocardial Infarction Reduces Respiration in Rat Cardiac Fibers, despite Adipose Tissue Mesenchymal Stromal Cell Transplant

Figure 8

Representative images of transmission electron microscopy analysis of cardiac tissue at the necrotic and fibrotic phase after AMI. (a) Sham-operated group, where the inset presents typical mitochondria (M) with well-structured cristae and dense matrix. Image of (b) BZ and (c) IZ from the PBS-24 h-treated group, which displayed mitochondrial membrane disruption (black arrow); the inset allows the visualization of small and distorted cristae together with matrix vacuolization. Collagen deposits indicative of fibrosis (F) are also visible in the IZ. (d) AD-MSC-24 h group showing a moderate amount of mitochondria between sarcomeres (S); the inset allows the visualization of slight disturbance of mitochondrial architecture. (e) IZ of AD-MSC-treated rats, showing mitochondrial membrane disruption, with multiple alterations in the mitochondria, including loss of cristae and matrix material, and crista disorganization in approximately half of all mitochondrial profiles. From fibrotic phase (f), BZ from rats treated with PBS shows multiple and variable ultrastructural alterations, including disorganization of the mitochondrial cristae, and loss of cristae, and matrix material in some mitochondria. (g) IZ from PBS-treated shows significant and accentuated ultrastructural alterations such as mitochondrial membrane disruption (black arrow) and fewer number of mitochondria, which had reduced matrix density and fewer or no cristae, as well as internal vacuoles. The cardiac tissue displayed the areas of fibrosis (F) with no myofibrils. Images from the fibrotic phase in the (h) BZ and (i) IZ from AD-MSC-treated rats show the same aspects observed in the PBS-treated conditions; (j) the total number of mitochondria from the PBS-24 h-treated group () and PBS-8 d-treated group () compared with the Sham group (); (k) the total number of mitochondria from BZ comparing the PBS group () and AD-MSC group () in the necrotic and fibrotic phase; and (l) the total number of mitochondria from IZ comparing the PBS group () and AD-MSC group () in the necrotic and fibrotic phase. Data represent the values. (j) ^# with respect to Sham; within the BZ and IZ subgroups, the levels of significance are indicated by the number of asterisks: , , and (1-way ANOVA with Bonferroni’s posttest). To compare the treated and nontreated groups, an unpaired -test was used (k, l). Other symbols in the panels—M: mitochondria; N: nucleus; S: sarcomeres. .