Optical control of sphingosine-1-phosphate formation and function.

Area of Science:

• Lipid signaling
• Molecular pharmacology
• Cell biology

Background:

• Sphingosine-1-phosphate (S1P) is a crucial signaling lipid involved in numerous physiological and pathophysiological processes.
• S1P exerts its functions through G-protein-coupled receptors (GPCRs) S1P1-5 and intracellular targets.
• Understanding S1P signaling pathways is vital for various biological and disease contexts.

Purpose of the Study:

• To develop novel photoswitchable analogs of S1P and sphingosine for precise optical control of sphingolipid biology.
• To investigate the efficacy of these analogs in controlling S1P receptor activity in vitro and in vivo.
• To establish a new methodology for optically probing sphingolipid functions with enhanced metabolic stability.

Main Methods:

• Synthesis of photoswitchable analogs: PhotoS1P and PhotoSph.
• Electrophysiology and Ca2+ mobilization assays to assess S1P receptor activity.
• In vivo studies in mice to evaluate PhotoS1P's effect on pain hypersensitivity.
• Lipid mass spectrometry to construct metabolic maps of PhotoS1P and PhotoSph.
• Assessment of metabolic stability compared to native S1P.

Main Results:

• PhotoS1P demonstrated optical control over S1P receptors 1-3.
• In vivo, PhotoS1P reversibly modulated S1P3-dependent pain hypersensitivity in mice, comparable to S1P.
• PhotoS1P exhibited prolonged metabolic stability, surpassing that of S1P.
• The formation of PhotoS1P and PhotoSph was light-dependent, confirming their photoswitchable nature.
• A metabolic map of the novel compounds was successfully constructed.

Conclusions:

• PhotoS1P and PhotoSph represent valuable tools for optically manipulating and studying sphingolipid signaling.
• The prolonged metabolic stability of PhotoS1P makes it ideal for in vitro and in vivo research on S1P biology.
• Light-dependent formation and activity offer a novel optical approach to investigate sphingolipid functions.