The disturbed integrity of myelin and white matter, along with dysregulation of the lipid metabolism, may be involved in
schizophrenia pathophysiology. Considering the crucial role of
sphingolipids in neurodevelopment, particularly in oligodendrocyte differentiation and myelination, we examined the role of
sphingolipid dynamics in the pathophysiology of
schizophrenia. We performed targeted mass spectrometry-based analysis of
sphingolipids from the cortical area and corpus callosum of postmortem brain samples from patients with
schizophrenia and controls. We observed lower
sphingosine-1-phosphate (S1P) levels, specifically in the corpus callosum of patients with
schizophrenia, but not in
major depressive disorder or
bipolar disorder, when compared with the controls. Patient data and animal studies showed that
antipsychotic intake did not contribute to the lowered S1P levels. We also found that lowered S1P levels in the corpus callosum of patients with
schizophrenia may stem from the upregulation of genes for S1P-degrading
enzymes; higher expression of genes for S1P receptors suggested a potential compensatory mechanism for the lowered S1P levels. A higher ratio of the sum of
sphingosine and
ceramide to S1P, which can induce apoptosis and cell-cycle arrest, was also observed in the samples of patients with
schizophrenia than in controls. These results suggest that an altered S1P metabolism may underlie the deficits in oligodendrocyte differentiation and myelin formation, leading to the structural and molecular abnormalities of white matter reported in
schizophrenia. Our findings may pave the way toward a novel therapeutic strategy.