A new lactoferrin-and iron-dependent lysosomal death pathway is induced by benzo [a] pyrene in hepatic epithelial cells

M Gorria, X Tekpli, M Rissel, O Sergent, L Huc… - Toxicology and applied …, 2008 - Elsevier
M Gorria, X Tekpli, M Rissel, O Sergent, L Huc, N Landvik, O Fardel, MT Dimanche-Boitrel…
Toxicology and applied pharmacology, 2008Elsevier
While lysosomal disruption seems to be a late step of necrosis, a moderate lysosomal
destabilization has been suggested to participate early in the apoptotic cascade. The origin
of lysosomal dysfunction and its precise role in apoptosis or apoptosis-like process still
needs to be clarified, especially upon carcinogen exposure. In this study, we focused on the
implication of lysosomes in cell death induced by the prototype carcinogen benzo [a] pyrene
(B [a] P; 50 nM) in rat hepatic epithelial F258 cells. We first demonstrated that B [a] P affected …
While lysosomal disruption seems to be a late step of necrosis, a moderate lysosomal destabilization has been suggested to participate early in the apoptotic cascade. The origin of lysosomal dysfunction and its precise role in apoptosis or apoptosis-like process still needs to be clarified, especially upon carcinogen exposure. In this study, we focused on the implication of lysosomes in cell death induced by the prototype carcinogen benzo[a]pyrene (B[a]P; 50 nM) in rat hepatic epithelial F258 cells. We first demonstrated that B[a]P affected lysosomal morphology (increase in size) and pH (alkalinization), and that these changes were involved in caspase-3 activation and cell death. Subsequently, we showed that lysosomal modifications were partly dependent on mitochondrial dysfunction, and that lysosomes together with mitochondria participate in B[a]P-induced oxidative stress. Using two iron chelators (desferrioxamine and deferiprone) and siRNA targeting the lysosomal iron-binding protease lactoferrin, we further demonstrated that both lysosomal iron content and lactoferrin were required for caspase-3 activation and apoptosis-like cell death.
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