Sphingomyelin signalling pathway

Activation of the sphingomyelin signaling pathway in intact EL4 cells and in a cell-free system by lL-1 beta. Science 259 519-522... 

Mathias, S., Younes, A., Kan, C. C., Orlow, I., Joseph, C., and Kolesnick, R. N., 1993, Activation of the sphingomyelin signaling pathway in intact EL4 cells and in a cell-free system by IL-1 beta Science 259 519-522... 

Cholesterol is an important structural component of cellular membranes, where it plays a role in modulating membrane fluidity and phase transitions, and, together with sphingomyelin, forms lipid rafts or caveolae, which are sites where proteins involved in diverse signaling pathways become concentrated. Furthermore, cholesterol is a precursor of oxysterols, steroid hormones, and bile acids. 

Kwon et al. (1996) used normal-phase HPLC to separate and quantify sphingomyelin (SPH). Flow injection ES-MS was then used to determine the SPH molecular species composition of isolated rat pancreatic islets. Kwon et al. concluded that sphingomyelin hydrolysis is not involved in the signalling pathway whereby cytokine interleukin-1 induces the overproduction of nitric oxide by pancreatic islets. They reported four molecular species of SPH SPH (16 0/d-18 l), (18 0/d-18 l), (22 0/d-18 l) and (24 0/d-18 l). They assumed that sphingosine (18 1) is the LCB however, studies of SPH from bovine brain (Jungalwala, Evans and McCluer, 1984), bovine milk (Morrison, 1969) and human plasma (Sweeley, 1963), show that there exist several LCB species, saturated as well as unsaturated, with one or two hydroxyl... 

Kolesnick, R. and Golde, D.W. The sphingomyelin pathway in tumor necrosis factor and interleukin-1 signaling (1994) Cell 77, 325-328... 

R. Kolesnick, and D. W. Golde, The Sphingomyelin Pathway in Tumor Necrosis Factor and Interleukin-1 Signaling, Cell, 77 (1994) 325-328. 

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. 

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