Stimulated\nEmission Depletion Imaging Reveals Mitochondrial\nPhenotypic Heterogeneity under Apoptosis Stimuli across Living Glioma\nModels

The mitochondrial phenotypes contribute to the understanding\nof\ndisease mechanisms and treatments, which are typically characterized\nthrough the omics methods. However, the high dynamics and phenotypic\nheterogeneity of mitochondria require high-resolution characterization\nwithin individual living cells. Therefore, we introduce a fluorescence\nanalysis method, based on two-color and fluorescence lifetime stimulated\nemission depletion (STED) super-resolution imaging, to explore mitochondrial\nphenotypic heterogeneity in human (U87) and mouse (GL261) glioma models.\nFurthermore, we used rotenone and etoposide to simulate the effects\nof antitumor drugs, inducing apoptosis through mitochondrial dysfunction,\nrespectively. The two-color labeling introduces intracellular parameters\nto qualitatively visualize changes in mitochondrial morphology, while\nfluorescence lifetime reflects the status of mitochondria and their\nmicroenvironment from the perspective of probe characteristics. This\nmethod reveals mitochondria phenotypic heterogeneity induced by the\napoptotic stimuli in human and mouse glioma models from a morphological\nperspective.