Physiological mediator of apoptosis

A signaling rheostat has been proposed where the relative level of SIP and ceramide determines cellular fate. This was based on the observation that ceramide, Fas and TNFa-mediated programmed cell death is suppressed by the addition of SIP (Cuvillier et al, 1996). The model assumes that ceramide is a physiological mediator of apoptosis although this is subject to controversy (Hofmann and Dixit, 1998 Kolesnick and Hannun, 1999). Indeed, sphingosine is also implicated as an apoptotic agent (see above). 

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