[Sphingolipid signaling: a potential pathway for TNF-alpha induced preconditioning]

Although cytokine activation has long been recognized to associate with cardiac ischemia and reperfusion, the concept that these cytokines may enhance some cardioprotective mechanisms has only recently been considered. Ischemic preconditioning is a biologic phenomenon that activates innate cytoprotective programs in the heart. Ischemic preconditioning has been described where a transient non-lethal ischemic "trigger" or endogenous molecules produced/released by ischemia enables the tissue to become more resistant/tolerant to subsequent potentially lethal ischemia. The mechanisms and signalling events involved in this cytoprotective program still remain obscure. Recently, it has been suggested that cytokine activation including tumour necrosis factor (TNF alpha) may play a key role in the preconditioned phenotype. Moreover, new studies have given the evidence that the exploration of cytokine-activated sphingolipid signalling pathways may enhance our understanding of the preconditioning program.