Mitochondria-Anchored Molecular Thermometer Quantitatively Monitoring Cellular Inflammations

Abstract

Temperature in mitochondria can be a critical indicator of cell metabolism. Given the highly dynamic and inhomogeneous nature of mitochondria, it remains a big challenge to quantitatively monitor the local temperature changes during different cellular processes. To implement this task, we extend our strategy on mitochondria-anchored thermometers from "on-off" probe <b>Mito-TEM</b> to a ratiometric probe <b>Mito-TEM 2.0</b> based on the Förster resonance energy transfer mechanism. <b>Mito-TEM 2.0</b> exhibits not only a sensitive response to temperature through the ratiometric changes of dual emissions but also the specific immobilization in mitochondria via covalent bonds. Both characters support accurate and reliable detection of local temperature for a long time, even in malfunctioning mitochondria. By applying <b>Mito-TEM 2.0</b> in fluorescence ratiometric imaging of cells and zebrafishes, we make a breakthrough in the quantitative visualization of mitochondrial temperature rises in different inflammation states.