Sphingomyelin and ceramide
CVDs, dyslipidaemia, Alzheimer disease, ischemia, Parkinson disease, depression, schizophrenia
NEURODEGENERATION, ISCHEMIA, INSULIN RESISTANCE, EVENTS, CELLULAR PROLIFERATION
Sphingomyelin and ceramide were other upregulated lipids in the VLCHF and VLCHF + HIIT groups. Sphingolipids are a large class of lipids with diverse functions in many (patho-) physiological processes. Sphingomyelin (SM) is the most abundant sphingolipid in the cell. It is one of the major components of the plasma membrane. The hydrolysis of SM increases the concentration of ceramide (Cer), a bioactive molecule, which is involved in cellular proliferation, growth and apoptosis. SM is essential for brain development and cognitive abilities and it is altered in neurodegeneration. Disturbances of enzymes involved in the SM cycle (i.e. ceramide/SM balance system) were observed in many CNS pathologies, including ischemia, Alzheimer disease, Parkinson disease, depression or schizophrenia (Bienias et al., Cer is a central molecule among the various sphingolipids because it is involved in synthesizing complex structural sphingolipids (sphingomyelin and ganglioside) and as a precursor of sphingosine-1-phosphate (S1P). Cer has been recognized a cause of selective insulin resistance and dyslipidaemia. Increased serum Cer levels are strongly associated with adverse CV risks and events. Therefore, decreasing ceramide levels through pharmacology and gene modification of the enzymes involved in the synthesis and degradation of ceramide can be a potential strategy to combat CVDs (Shu et al., The increased serum Cer level in our study might be related to the marked increase in fat intake in the VLCHF diet groups. When FA availability exceeds the cell’s storage and energetic capacities, Cers and other intermediates in these biosynthetic pathways start to accrue. Further, Cers initiate actions to enable storage or utilization of FAs to help the cell adapt to the surplus of FAs and protect membrane bilayers (Tippetts et al., We showed also a significant increase of sulphated glycosphingolipids (GSLs). However, there is still limited knowledge about their biological function. The sulphated GSLs play an important role in cell–cell communication (Honke et al., 