Three-dimensional reconstruction of the intercalated disc including the intercellular junctions by applying volume scanning electron microscopy

In this study, we generated 3-D datasets using serial block-face scanning electron microscopy (SBF-SEM) and focused ion beam SEM (FIB-SEM), the latter resulting in datasets with 5  nm isotropic voxels. We visualized cardiomyocytes in murine ventricular heart tissue and, for the first time, we could three-dimensionally reconstruct the ID including desmosomes and GJs with 5 nm precision in a large volume. Results show in three dimensions a highly folded structure of the ID, w ith the presence of GJs and desmosomes in both plicae and interplicae regions. We observed close contact of GJs with mitochondria and a variable spatial distribution of the junctions. Based on measurements of the shape of the intercellular junctions in 3-D, it is seen that GJs and desmosomes vary in size, depending on the region within the ID. This demonstrates that volume EM is essential to visualize morphological changes and its potential to quantitatively determine structural changes between normal and pathological conditions, e.g., cardiomyopathies.

Source: Histochemistry and Cell Biology - March 5, 2018 Category: Biomedical Science Source Type: research