Figure 4. GJA1-20k increases mitochondrial content.
(A) GST-GFP control or GJA1-20k-GFP are introduced into the heart by the recombinant AAV9 gene delivery system at 3 × 1010 vector genomes per mouse. Immunofluorescence confocal imaging of heart tissue confirms the expression of the GFP-tagged proteins at 4 weeks after AAV9 expression as compared with a PBS control heart with no AAV9. Scale bar: 50 μm. (B) Electron microscope images of left ventricular tissue isolated from AAV9-GJA1-20k– or AAV9-GST–expressing mouse hearts. Insets show mitochondria, with cardiomyocyte area outlined using a black line. Scale bar: 2 μm. (C) Quantification of the percentage area of the cardiomyocyte occupied by mitochondria in each group (number of images assessed is shown on the graph). Data in C are mean ± SEM. **P < 0.01, ****P < 0.0001, unpaired t test.