A Small Molecule Fluorogenic Probe for the Detection of Sphingosine in Living Cells
ABSTRACTThe single-chained sphingolipid sphingosine is an essential structural lipid and signaling molecule. Abnormal sphingosine metabolism is observed in several diseases, including cancer, diabetes, and Alzheimer’s. Despite its biological importance, there are a lack of tools for detecting sphingosine in living cells. This is likely due to the broader challenge of developing highly selective and live-cell compatible affinity probes for hydrophobic lipid species. In this work, we have developed a small molecule fluorescent turn-on probe for labeling sphingosine in living cells. This probe utilizes a selective reaction between sphingosine and salicylaldehyde esters to fluorescently label sphingosine molecules. We demonstrate that this probe exhibits a dose-dependent response to sphingosine and is able to detect endogenous pools of sphingosine. Using our probe, we successfully detected sphingosine accumulation in live Niemann-Pick type C1 (NPC1) patient cells, a lipid transport disorder in which increased sphingosine mediates disease progression. This work provides a simple and accessible method for the detection of sphingosine and should facilitate study of this critical signaling lipid in biology and disease.Competing Interest StatementThe authors have declared no competing interest.View Full Text