Altered ceramide and sphingosine expression during the induction phase of ischemic acute renal failure

Abstract

(1) sphingosine and ceramide fluxes are hallmarks of early ischemic/reperfusion injury; (2) these changes occur via divergent metabolic pathways; and (3) that ceramide increments can affect divergent injury pathways, and that sphingosine and ceramide have potent cell signaling effects, suggest that the currently documented sphingosine/ ceramide fluxes could have important implications for the induction phase and evolution of post-ischemic ARF.

Ceramide synthase is essential for endonuclease-mediated death of renal tubular epithelial cells induced by hypoxia-reoxygenation

“…In terms of the pathway for ceramide generation in hypoxic injury, an in vitro study showed that hypoxic injury to PC12 cells results in enhanced ceramide generation through activation of neutral sphingomyelinase (37). In contrast, the study by Zager et al (40) showed that the ceramide level is increased in an in vivo model of ischemia-reperfusion injury to kidneys or in an in vitro model of hypoxic injury to cultured kidney cells accompanied by a decrease in the activity of neutral sphingomyelinase. However, recent studies suggested the role of ceramide synthase for enhanced generation of ceramide in different models (8,23,28).…”

“…Although the role of ceramide has been studied in apoptotic cell death in response to a variety of stimuli, there is limited information of a role of ceramide in hypoxia-reoxygenation injury. In vivo studies of ischemic injury to the kidney (39,40) or brain (19) as well as in vitro study of hypoxic injury to cultured PC12 cells (37) have shown an increase in ceramide level. However, the cause-effect relationship between an alteration of ceramide and cytotoxicity is not known in hypoxiareoxygenation injury to renal tubular epithelial cells, and the pathways for ceramide generation in ischemia-reperfusion or hypoxia-reoxygenation injury remain to be elucidated.…”

Modulation of ACTH-induced cortisol release by polyunsaturated fatty acids in interrenal cells from gilthead seabream, Sparus aurata

“…This is the case in other organs such as testicles where medium concentrations of ARA (3-30 mM) induced testosterone production in testicular cells of male sea bass, whereas high concentrations (300 mM) inhibited it (Asturiano 1999). Despite the fact that no previous data has been published on in vitro exposures of fish interrenal cells to fatty acids, cytotoxic effects at the membrane level have been found in mammalian tissues, including renal cells (Zager et al 1997). Particularly, excess of ARA and its derived eicosanoids has been found to cause apoptosis associated with oxidative stress in human leukocytes (Pompeia et al 2002).…”

Mitochondrial Ceramide in Stroke

“…In the whole kidney IR model, ceramide content was increased about 1.8-fold in the injured tissue during the reperfusion phase (Zager et al, 1997) which was not accompanied by SM hydrolysis. In fact, there was no SM content change in post-IR tissue.…”