Sphingomyelin degradation

Adinehzadeh M, Reo NV. 1998. Effects of peroxisome proliferators on rat liver phospholipids Sphingomyelin degradation may be involved in hepatotoxic mechanism of perfluorodecanoic acid. Chem Res Toxicol 11 428-440. 

Ferlinz, K., linke, T., Bartelsen, O., Weiler, M., and Sandhoff, K., 1999, Stimulation of lysosomal sphingomyelin degradation by sphingolipid activator proteins. Chem Phys Lipids 102 35-43. 

Christomanou, H., and Kleinschmidt, T., Isolation of two forms of an activation protein for the enzymic sphingomyelin degradation from human Gaucher spleen. Biol. Chem. Hoppe-Seyler 366, 245-256 (1985). 

Porn, M. I., Tenhunen, J., and Slotte, J. P. (1991). Increased steroid hormone secretion in mouse Leydig tumor cells after induction of cholesterol translocation by sphingomyelin degradation. Biochim Biophys Acta 1093, 7-12. 

The major pathway of sphingomyelin degradation involves a Sf>ecial PLC, a sphingomyelinase. The enzyme is secreted by B. cereus while several mammalian sphingomyelinases play a prominent role in signal transduction in mammalian systems. The description of sphingolipids and their metabolism is covered in Chapter 13. 

Sphingomyelin, a ubiquitous component of cell membranes, especially neuronal membranes, is normally degraded within lysosomes by the enzyme sphingomyelinase. 

Lysophospholipids have been found in butter serum by Cho et al. (1977). They characterized the sn-1 and -2 lysophosphatidylcholines and phosphatidylethanolamines. It is not known if these compounds are products of degradation or remnants of biosynthesis. Cho et al. (1977) searched for, but did not find, another possible product of enzymatic degradation of milk, phosphatidic acid. Phosphatidic acid can be formed by the action of phospholipase D on phosphatidylcholine, for example, but this enzymatic activity was not detected. The compound is also an important intermediate in the biosynthesis of lipids, but the concentration in tissue is always very low. The amount is also low in milk. Cho et al. (1977) found 1.2 and 0.9 (percent of total lipid P) of the lyso compounds above. The quantities of the other phospholipids were phosphatidylethanolamine, 27.3 -choline, 29.1 -serine, 13.4 -inositol, 2.5 and sphingomyelin, 25.6. 

Ohvo H, Olsio C, Slotte JP (1997) Effects of sphingomyelin and phosphatidylchoUne degradation on cyclodextrin-mediated cholesterol efflux in culmred fibroblasts. Biochim Biophys Acta 1349 131-141... 

Ceramides are a group of sphingolipids with the general structure shown as part of sphingomyelin here. Ceramides are made either as part of sphingolipid biosynthesis or degradation. 

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