Galactosylceramides
Galactosylceramides (cerebrosides) are found primarily in neuronal tissues and are the major glycosphingolipids in the central nervous system. They act, along with other molecules, to form part of the structural support of the myelin sheath, of which galactosylceramides are the largest single component.1 Cerebrosides are involved in a very wide range of biological activities such as cell agglutination, intracellular communication, cellular development, and antitumor/cytotoxic effects.2 They can be metabolized into sulfatide which is also abundant in the nervous system and myelin sheaths. Due to the relatively high melting point of cerebrosides (much greater than physiological body temperature) they have a para-crystalline structure. Krabbe disease (globoid cell leukodystrophy) is characterized by a deficiency in the enzyme galactosylceramidase, which is responsible for degrading cerebroside. This deficiency leads to an accumulation of cerebroside and psychosine (which is very cytotoxic) resulting in demyelination of nerves and loss of axonal conductivity.3
References:
- S.L. Miller and L. Denisova. “Cycloserine-induced decrease of cerebroside in myelin” Lipids, Vol. 33:4 pp. 441-443, 1998
- X. Zhou, L. Tang and Y. Liu “An Isomeric Mixture of Novel Cerebrosides Isolated from Impatiens pritzellii Reduces Lipopolysaccharide-Induced Release of IL-18 from Human Peripheral Blood Mononuclear Cells” Lipids, Vol. 44:8 pp. 759-763, 2009
- X. Han and H. Cheng “Characterization and direct quantitation of cerebroside molecular species from lipid extracts by shotgun lipidomics” Journal of Lipid Research, Vol. 46 pp. 163-175, 2005