N Ueda1, G P Kaushal, X Hong, S V Shah. 1. Division of Nephrology, University of Arkansas for Medical Sciences, Little Rock, USA. uedanorishi@exchange.uams.edu
Abstract
BACKGROUND: Ceramide has been implicated to be a second messenger in the cell signaling pathway involved in cell growth, proliferation, and apoptotic cell death. However, there is little information of a role of ceramide in DNA damage and cell death in hypoxic injury known to induce necrotic cell death. METHODS: Ceramide generation was measured in LLC-PK1 cells exposed to chemical hypoxia with a mitochondrial electron transport inhibitor, antimycin A and glucose deprivation. The effect of inhibition of ceramide generation on chemical hypoxia-induced DNA damage and cell death and the effect of exogenous ceramide on cellular injury were also determined. RESULTS: Chemical hypoxia resulted in a rapid increase in ceramide production prior to any evidence of DNA damage and cell death in LLC-PK1 cells. The inhibitor of ceramide synthase, fumonisin B1, provided a marked protection against chemical hypoxia-induced DNA strand breaks, DNA fragmentation and cell death. Fumonisin B1 did not affect adenosine triphosphate (ATP) depletion induced by antimycin A, suggesting that fumonisin B1 does not alter cellular uptake of antimycin A. We confirmed the ability of ceramide synthase inhibitor, fumonisin B1, to suppress chemical hypoxia-induced ceramide generation. Exposure of LLC-PK1 cells to synthetic ceramide, C2- and C6-ceramide, but not C2-dihydroceramide, the structural analog of C2-ceramide, resulted in DNA strand breaks, DNA fragmentation and cell death in a dose- and time-dependent manner similar to the effect of chemical hypoxia. CONCLUSIONS: Our data indicate that ceramide is a key modulator for DNA damage and cell death in chemical hypoxia to renal tubular epithelial cells.
BACKGROUND:Ceramide has been implicated to be a second messenger in the cell signaling pathway involved in cell growth, proliferation, and apoptotic cell death. However, there is little information of a role of ceramide in DNA damage and cell death in hypoxic injury known to induce necrotic cell death. METHODS:Ceramide generation was measured in LLC-PK1 cells exposed to chemical hypoxia with a mitochondrial electron transport inhibitor, antimycin A and glucose deprivation. The effect of inhibition of ceramide generation on chemical hypoxia-induced DNA damage and cell death and the effect of exogenous ceramide on cellular injury were also determined. RESULTS: Chemical hypoxia resulted in a rapid increase in ceramide production prior to any evidence of DNA damage and cell death in LLC-PK1 cells. The inhibitor of ceramide synthase, fumonisin B1, provided a marked protection against chemical hypoxia-induced DNA strand breaks, DNA fragmentation and cell death. Fumonisin B1 did not affect adenosine triphosphate (ATP) depletion induced by antimycin A, suggesting that fumonisin B1 does not alter cellular uptake of antimycin A. We confirmed the ability of ceramide synthase inhibitor, fumonisin B1, to suppress chemical hypoxia-induced ceramide generation. Exposure of LLC-PK1 cells to synthetic ceramide, C2- and C6-ceramide, but not C2-dihydroceramide, the structural analog of C2-ceramide, resulted in DNA strand breaks, DNA fragmentation and cell death in a dose- and time-dependent manner similar to the effect of chemical hypoxia. CONCLUSIONS: Our data indicate that ceramide is a key modulator for DNA damage and cell death in chemical hypoxia to renal tubular epithelial cells.
Authors: Evi Vlassaks; Chiara Mencarelli; Maria Nikiforou; Eveline Strackx; Maria J Ferraz; Johannes M Aerts; Marc H De Baets; Pilar Martinez-Martinez; Antonio W D Gavilanes Journal: J Lipid Res Date: 2013-04-26 Impact factor: 5.922
Authors: R T Riley; E Enongene; K A Voss; W P Norred; F I Meredith; R P Sharma; J Spitsbergen; D E Williams; D B Carlson; A H Merrill Journal: Environ Health Perspect Date: 2001-05 Impact factor: 9.031