Vulvodynia: Identification of Potential Relevant Biomarkers

Sphingosine-1-phosphate (S1P) is a potent anti-apoptotic sphingolipid with potent pro-inflammatory actions which are driven in most part by activation of the S1P receptor subtype S1PR158. Biologically active S1P is generated by the phosphorylation of sphingosine, catalyzed by two sphingosine kinases (SphK1, SphK2). S1P levels are further regulated by its dephosphorylation by two phosphatases (SGPP1 and SGPP2) and through degradation by one lyase (SGPL1). Once released S1P initiates signaling through a family of five cognate G protein-coupled receptors (S1PR1-5), leading to various cellular responses9. S1P signaling has important roles in inflammation and cancer. S1P acting via the S1PR1 has been implicated in the development of pain of several etiologies as discovered by Salvemini and coworkers and subsequently extended by others. FTY720 (fingolimod/Gilenya®) is the first orally available agent approved by the FDA for the treatment of relapsing-remitting multiple sclerosis (MS). The work by Salvemini's group in providing a mechanistic basis for understanding chronic pain through the S1P/S1PR1 axis, provides a promising therapeutic target for the use of agents like FTY720 as a novel treatment for pain. Ongoing work by the Salvemini's lab suggests that increased expression of S1PR1 in circulating peripheral blood leukocytes (PBLs) may provide a relevant biomarker to predict severity and pain induction outcomes as well as predict patient responses to anti-S1PR1 approaches.