Sphingolipid Regulation of Genome Stability: Stress Signaling, Chromatin Control, and Organelle Dysfunction

Sphingolipid metabolism has emerged as a regulatory interface between lipid homeostasis, organelle stress, and genome maintenance. Although sphingolipids are essential structural components of cellular membranes, specific metabolites also function as bioactive mediators that shape cellular responses to genotoxic stress. In this review, we examine how canonical and atypical sphingolipid pathways influence the DNA damage response through three mechanistic axes. First, ceramide-centered stress signaling links radiation, chemotherapy, and inflammatory injury to kinase and phosphatase pathways, mitochondrial apoptosis, and checkpoint-associated cell-fate decisions. Second, nuclear sphingolipid metabolism, particularly sphingosine kinase 2-dependent production of sphingosine-1-phosphate, regulates chromatin-associated transcriptional programs through modulation of histone deacetylase activity. Third, persistent sphingolipid imbalance promotes metabolic stress by disrupting lysosomal turnover, mitochondrial function, endoplasmic reticulum homeostasis, and redox balance, thereby increasing endogenous oxidative DNA damage. We also discuss atypical sphingolipids, including 1-deoxysphingolipids generated through altered serine palmitoyltransferase substrate utilization, as emerging mediators of mitochondrial dysfunction and genome instability. Finally, we consider the relevance of these mechanisms to cancer, lysosomal storage disorders, and neurodegenerative diseases, where sphingolipid dysregulation may influence therapeutic responses and disease progression. Together, these position sphingolipid metabolism as an integrated regulatory network connecting cellular stress signaling, chromatin regulation, organelle dysfunction, and genome stability.