AUTHOR=Collins Helen E. , Kane Mariame Selma , Litovsky Silvio H. , Darley-Usmar Victor M. , Young Martin E. , Chatham John C. , Zhang Jianhua TITLE=Mitochondrial Morphology and Mitophagy in Heart Diseases: Qualitative and Quantitative Analyses Using Transmission Electron Microscopy JOURNAL=Frontiers in Aging VOLUME=2 YEAR=2021 URL=https://www.frontiersin.org/journals/aging/articles/10.3389/fragi.2021.670267 DOI=10.3389/fragi.2021.670267 ISSN=2673-6217 ABSTRACT=

Transmission electron microscopy (TEM) has long been an important technique, capable of high degree resolution and visualization of subcellular structures and organization. Over the last 20 years, TEM has gained popularity in the cardiovascular field to visualize changes at the nanometer scale in cardiac ultrastructure during cardiovascular development, aging, and a broad range of pathologies. Recently, the cardiovascular TEM enabled the studying of several signaling processes impacting mitochondrial function, such as mitochondrial fission/fusion, autophagy, mitophagy, lysosomal degradation, and lipophagy. The goals of this review are to provide an overview of the current usage of TEM to study cardiac ultrastructural changes; to understand how TEM aided the visualization of mitochondria, autophagy, and mitophagy under normal and cardiovascular disease conditions; and to discuss the overall advantages and disadvantages of TEM and potential future capabilities and advancements in the field.