Superiority of SpiroZin2 Versus FluoZin-3 for monitoring vesicular Zn2+ allows tracking of lysosomal Zn2+ pools.
Yu HanJacob M GoldbergStephen J LippardAmy E PalmerPublished in: Scientific reports (2018)
Small-molecule fluorescent probes are powerful and ubiquitous tools for measuring the concentration and distribution of analytes in living cells. However, accurate characterization of these analytes requires rigorous evaluation of cell-to-cell heterogeneity in fluorescence intensities and intracellular distribution of probes. In this study, we perform a parallel and systematic comparison of two small-molecule fluorescent vesicular Zn2+ probes, FluoZin-3 AM and SpiroZin2, to evaluate each probe for measurement of vesicular Zn2+ pools. Our results reveal that SpiroZin2 is a specific lysosomal vesicular Zn2+ probe and affords uniform measurement of resting Zn2+ levels at the single cell level with proper calibration. In contrast, FluoZin-3 AM produces highly variable fluorescence intensities and non-specifically localizes in the cytosol and multiple vesicular compartments. We further applied SpiroZin2 to lactating mouse mammary epithelial cells and detected a transient increase of lysosomal free Zn2+ at 24-hour after lactation hormone treatment, which implies that lysosomes play a role in the regulation of Zn2+ homeostasis during lactation. This study demonstrates the need for critical characterization of small-molecule fluorescent probes to define the concentration and localization of analytes in different cell populations, and reveals SpiroZin2 to be capable of reporting diverse perturbations to lysosomal Zn2+.
Keyphrases
- living cells
- small molecule
- single cell
- fluorescent probe
- single molecule
- heavy metals
- protein protein
- quantum dots
- rna seq
- dairy cows
- high throughput
- risk assessment
- blood pressure
- heart rate variability
- stem cells
- heart rate
- human milk
- brain injury
- adverse drug
- fluorescence imaging
- mass spectrometry
- low birth weight
- drug induced
- preterm birth