No abstract

Background/Aims: The sesquiterpene lactone Costunolide is effective against various disorders including inflammation and malignancy. The substance is effective in part by triggering suicidal death or apoptosis of tumor cells. Mechanisms involved include altered function of transcription factors and mitochondria. Erythrocytes lack nuclei and mitochondria but are – in analogy to apoptosis of nucleated cells – able to enter suicidal erythrocyte death or eryptosis, characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Triggers of eryptosis include increase of cytosolic Ca²⁺ activity ([Ca²⁺]_i), oxidative stress and ceramide. The present study explored, whether Costunolide induces eryptosis and, if so, to shed light on the mechanisms involved. Methods: Phosphatidylserine exposure at the cell surface was estimated from annexin-V-binding, cell volume from forward scatter, [Ca²⁺]_i from Fluo3-fluorescence, reactive oxygen species (ROS) formation from 2’,7’-dichlorodihydrofluorescein (DCF)-dependent fluorescence, and ceramide abundance utilizing specific antibodies. Results: A 48 hours exposure of human erythrocytes to Costunolide (15 µg/ml) significantly enhanced the percentage of annexin-V-binding cells, significantly decreased forward scatter and significantly increased Fluo3-fluorescence, DCF-fluorescence, and ceramide abundance. The effect of Costunolide on annexin-V-binding was significantly blunted by removal of extracellular Ca²⁺. Conclusion: Costunolide triggers cell shrinkage and phospholipid scrambling of the erythrocyte cell membrane, an effect at least in part due to Ca²⁺ entry and paralleled by oxidative stress and ceramide formation.

Background/Aims: The taurine derivative Taurolidine is effective against diverse bacteria and tumor growth. In the treatment of cancer, the substance is effective in part by triggering suicidal death or apoptosis of tumor cells. The Taurolidine-induced apoptosis involves mitochondria. Erythrocytes lack mitochondria but are nevertheless able to enter suicidal erythrocyte death or eryptosis, which is characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Signaling of eryptosis includes increase of cytosolic Ca²⁺ activity ([Ca²⁺]_i), oxidative stress and ceramide. The present study explores, whether Taurolidine induces eryptosis and, if so, which cellular mechanisms are involved. Methods: Phosphatidylserine exposure at the cell surface was estimated using annexin-V-binding, cell volume using forward scatter, [Ca²⁺]_i using Fluo3-fuorescence, reactive oxygen species (ROS) formation using 2’,7’-dichlorodihydrofuorescein (DCF)-dependent fluorescence, and ceramide abundance using specific antibodies. Results: A 48 hours exposure of human erythrocytes to Taurolidine (60 µg/ml) significantly enhanced the percentage of annexin-V-binding cells, significantly decreased forward scatter and significantly increased Fluo3-fluorescence and ceramide abundance, but not DCF-fluorescence. The effect of Taurolidine on annexin-V-binding was virtually abrogated by removal of extracellular Ca²⁺. Conclusion: Taurolidine triggers cell shrinkage and phospholipid scrambling of the erythrocyte cell membrane, an effect at least in part due to Ca²⁺ entry and paralleled by increase of ceramide abundance.

The original version of this article contains several mistakes due to the below missed corrections: Line 21: DELETE the "," after "scatter" and DELETE the "significantly increased"; ADD the "significantly increased" after "Fluo3 fluorescence and" LIne 23: add "In conclusion, phenoxodiol" instead of Phenoxodiol; DELETE Ca2+ entry Line 24: DELETE and Line 155: decreased INSTEAD OF increased Line 200: decreases INSTEAD OF increases Line 201: and INSTEAD OF, but Line 204: DELETE could still have partially been due to increases of [Ca2+]i, but Line 205: REMOVE this Line 234: DELETE Ca2+ entry and The original article has been corrected. Publisher's note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

No abstract