The contribution of the sphingosine 1-phosphate signaling pathway to chronic kidney diseases: recent findings and new perspectives.

Chronic kidney disease (CKD) is a multifactorial condition with diverse etiologies, such as diabetes mellitus, hypertension, and genetic disorders, often culminating in end-stage renal disease (ESRD). A hallmark of CKD progression is kidney fibrosis, characterized by the excessive accumulation of extracellular matrix components, for which there is currently no effective anti-fibrotic therapy. Recent literature highlights the critical role of sphingosine 1-phosphate (S1P) signaling in CKD pathogenesis and renal fibrosis. This review provides an in-depth analysis of the latest findings on S1P metabolism and signaling in renal fibrosis and in specific CKDs, including diabetic nephropathy (DN), lupus nephritis (LN), focal segmental glomerulosclerosis (FSGS), Fabry disease (FD), and IgA nephropathy (IgAN). Emerging studies underscore the therapeutic potential of modulating S1P signaling with receptor modulators and inhibitors, such as fingolimod (FTY720) and more selective agents like ozanimod and cenerimod. Additionally, the current knowledge about the effects of established kidney protective therapies such as glucocorticoids and SGLT2 and ACE inhibitors on S1P signaling will be summarized. Furthermore, the review highlights the potential role of S1P as a biomarker for disease progression in CKD models, particularly in Fabry disease and diabetic nephropathy. Advanced technologies, including spatial transcriptomics, are further refining our understanding of S1P's role within specific kidney compartments. Collectively, these insights emphasize the need for continued research into S1P signaling pathways as promising targets for CKD treatment strategies.