Therapeutic Potential of the Modulation of Sphingosine-1-Phosphate Receptors

It is accepted that sphingolipids (SL) are not only structural lipids in cellular membranes, but also key regulators of different cell process. Sphingosine-1-phosphate (S1P) is a member of this family involved, inter alia, in cell migration, angiogenesis and cell proliferation processes, being able to play different intracellular and extracellular roles. When S1P is transported out of the cell, it binds S1P specific G protein-coupled receptors, which are mainly involved in the regulation of the immune, vascular and nervous systems. These effects account for the vast diversity of functions that arise from the activation of S1P receptors. Deregulation of S1P levels is correlated with several pathologies, such as autoimmune disorders and cancer. Consequently, the correct modulation of these receptors represents a valuable approach for the development of new therapeutic strategies. Along this line, the non-selective S1P receptor agonist fingolimod (FTY720) has been commercialized recently for the treatment of multiple sclerosis and several related S1P receptor modulators are ongoing clinical trials. However, despite the progress in this field, the biological functions of S1P receptors are not still well elucidated. For this reason, several studies are being developed in order to better understand the functions of these receptors, making use of new selective S1P receptor agonists and antagonists as pharmacological tools.