Role of glycosphingolipids and therapeutic perspectives on Alzheimer's disease.

Alzheimer's disease (AD) is a devastating neurodegenerative disorder dividing into two forms, early onset familial and late onset sporadic forms. Early onset genetic cases (familial AD (FAD)) constitute about 10% of all AD cases. Heretofore, highly fibrillinogenic and pathological Abeta peptide formation is regarded as the fundamental molecular basis for this disorder. Recent enormous efforts to find out a pathogenesis, however, have revealed that this disorder has a multiplicity of causes such as glycosphingolipids abnormalities, impairment of neurotrophin signaling, protein trafficking, and protein turnover. Most of these aspects were disclosed by the studies on FAD-related presenilin. In this review, we will focus on the current knowledge of many abnormal aspects of cellular lipids, especially glycosphingolipids other than a pathogenic Abeta production caused by the mutant presenilins as a model system. Moreover, we will discuss how these glycosphingolipids abnormalities cause the pathological conditions found in this disorder.