Tsao H.-CLiao Y.-FPratiwi F.WMou C.-YLin Y.-JPan C.-YCHIEN-YUAN PANYIT-TSONG CHEN2021-07-262021-07-26202114319276https://www.scopus.com/inward/record.uri?eid=2-s2.0-85100321376&doi=10.1017%2fS1431927620024940&partnerID=40&md5=a20499fda0619cbb524ef971885e3622https://scholars.lib.ntu.edu.tw/handle/123456789/573266Lysosomes are integration hubs for several signaling pathways, such as autophagy and endocytosis, and also crucial stores of ions, including Zn2+. Lysosomal dysfunction caused by changes in their morphology by fusion and fission processes can result in several pathological disorders. However, the role of Zn2+ in modulating the morphology of lysosomes is unclear. The resolution of conventional epifluorescence microscopy restricts accurate observation of morphological changes of subcellular fluorescence punctum. In this study, we used a modified epifluorescence microscopy to identify the center of a punctum from a series of z-stack images and calculate the morphological changes. We stained primary cultured rat embryonic cortical neurons with FluoZin3, a Zn2+-sensitive fluorescent dye, and Lysotracker, a lysosome-specific marker, to visualize the distribution of Zn2+-enriched vesicles and lysosomes, respectively. Our results revealed that treating neurons with N,N,N,N-tetrakis(2-pyridylmethyl)ethylenediamine, a cell-permeable Zn2+ chelator, shrank Zn2+-enriched vesicles and lysosomes by up to 25% in an hour. Pretreating the neurons with YM201636, a blocker of lysosome fission, could suppress this shrinkage. These results demonstrate the usefulness of the modified epifluorescence microscopy for investigating the homeostasis of intracellular organelles and related disorders. Copyright ? The Author(s), 2021. Published by Cambridge University Press on behalf of the Microscopy Society of America.[SDGs]SDG3journal article10.1017/S1431927620024940334872122-s2.0-85100321376