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Stimulation of erythrocyte phospholipid scrambling by enniatin A
Author(s) -
Jilani Kashif,
Qadri Syed M.,
Lang Elisabeth,
Zelenak Christine,
Rotte Anand,
Bobbala Diwakar,
Lang Florian
Publication year - 2011
Publication title -
molecular nutrition and food research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.495
H-Index - 131
eISSN - 1613-4133
pISSN - 1613-4125
DOI - 10.1002/mnfr.201100156
Subject(s) - phosphatidylserine , annexin , phospholipid , apoptosis , cytosol , chemistry , programmed cell death , phospholipid scramblase , biochemistry , annexin a5 , staurosporine , biology , microbiology and biotechnology , protein kinase c , kinase , membrane , enzyme
Scope : Enniatin A, a peptide antibiotic and common food contaminant, triggers mitochondrial dysfunction and apoptosis. Even though lacking mitochondria, erythrocytes may similarly undergo suicidal cell death or eryptosis. Eryptosis is characterized by cell shrinkage and cell membrane phospholipid scrambling. Triggers of phospholipid scrambling include energy depletion and increase in cytosolic Ca 2+ activity ([Ca 2+ ] i ). The present study explored whether enniatin A triggers phospholipid scrambling. Methods and results : Phospholipid scrambling was estimated from annexin‐V‐binding, cell volume from forward scatter (FSC), [Ca 2+ ] i from Fluo3‐fluorescence, cytosolic ATP‐concentration ([ATP] i ) using a luciferase assay and hemolysis from hemoglobin release. Exposure of erythrocytes for 48 h to enniatin A (≥2.5 μM) significantly increased [Ca 2+ ] i , decreased [ATP] i , decreased FSC, triggered annexin‐V‐binding and elicited hemolysis. Annexin‐V‐binding affected 25%, and hemolysis 2% of treated erythrocytes. Decreased [ATP] i by glucose depletion for 48 h was similarly followed by increased [Ca 2+ ] i , decreased FSC and annexin‐V‐binding. Enniatin A augmented the effect on [Ca 2+ ] i and annexin‐V‐binding, but not on FSC. Annexin‐V‐binding was blunted by Ca 2+ removal, by the cation channel inhibitor amiloride (1 mM), by the protein kinase C inhibitor staurosporine (500 nM) but not by the pancaspase inhibitor zVAD (10 μM). Conclusion : The food contaminant enniatin A triggers ATP depletion and increases cytosolic Ca 2+ activity, effects resulting in suicidal erythrocyte death.