Sphingolipids and brain resident macrophages in neuroinflammation: an emerging aspect of nervous system pathology

Abstract

Sphingolipid metabolism is deeply regulated along the differentiation and development of the central nervous system (CNS), and the expression of a peculiar spatially and temporarily regulated sphingolipid pattern is essential for the maintenance of the functional integrity of the nervous system. Microglia are resident macrophages of the CNS involved in general maintenance of neural environment. Modulations in microglia phenotypes may contribute to pathogenic forms of inflammation. Since defects in macrophage/microglia activity contribute to neurodegenerative diseases, it will be essential to systematically identify the components of the microglial cell response that contribute to disease progression. In such complex processes, the sphingolipid systems have recently emerged to play important roles, thus appearing as a key new player in CNS disorders. This review provides a rationale for harnessing the sphingolipid metabolic pathway as a potential target against neuroinflammation.

Figure 1

Schematic representation of main sphingolipid metabolic pathway. SM: sphingomyelin; Cer: ceramide; A-SMase: acid sphingomyelinase; N-SMase: neutral sphingomyelinase; A-CDase: acid ceramidase; N-CDase: neutral ceramidase; SMS: sphingomyelin synthase; Sph: sphingosine; S1P: sphingosine-1-phosphate; SK: sphingosine kinase; dhCer: dihydroceramide; CerS: ceramide synthase; GluCer: glucosylceramide; GCS: glucosylceramide synthase; GT: glycosyltransferase; GSL: ganglioside; Ser: serine.