Ceramides in Alzheimer’s Disease: Key Mediators of Neuronal Apoptosis Induced by Oxidative Stress and Aβ Accumulation

Figure 4

Interplay between neurons and astroglia in sphingolipid metabolism. Conditioned medium from palmitic acid- (PA-) treated astrocytes upregulates neuronal β-secretase (BACE1) leading to Aβ accumulation. PA increases de novo synthesis of ceramide and downregulates glucose uptake in astroglia. PA-induced activation of serine palmitoyltransferase (SPT) leads to production of proinflammatory cytokines, which after release in surrounding media activate neuronal sphingomyelinases (SMases), increase the ceramide pool, and ultimately lead to increase in Aβ accumulation.