Two-Color Visualization of Cholesterol Fluctuation in Plasma Membranes by Spatial Distribution-Controllable Single Fluorescent Probes

Visualizing
cholesterol (CL) fluctuation in plasma membranes is
a crucially important yet challenging task in cell biology. Here,
we proposed a new imaging strategy based on permeability changes of
plasma membranes triggered by different CL contents to result in controllable
spatial distribution of single fluorescent probes (SF-probes) in subcellular
organelles. Three spatial distribution-controllable SF-probes (PMM-Me,
PMM-Et, and PMM-Bu) for imaging CL fluctuation in plasma membranes
were rationally developed. These SF-probes target plasma membranes
and mitochondria at normal CL levels, while they display solely staining
in plasma membranes and mitochondria at increased and decreased CL
levels, respectively. These polarity-sensitive probes also show distinct
emission colors with fluorescence peaks of 575 and 620 nm in plasma
membranes and mitochondria, respectively. Thus, the CL fluctuation
in plasma membranes can be clearly visualized by means of the spatially
distributed and two-color emissive SF-probes.