Induction of Suicidal Erythrocyte Death by Novobiocin

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Background: The anticarcinogenic drug PRIMA-1 (p53 reactivation and induction of massive apoptosis 1) induces suicidal death of tumor cells, an effect in large part attributed to the up-regulation of the proapoptotic transcription factor p53. Erythrocytes are lacking gene transcription but are nevertheless able to enter eryptosis, a suicidal erythrocyte death characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Stimulators of eryptosis include increase of cytosolic Ca²⁺-activity ([Ca²⁺]_i) and ceramide formation. The present study tested whether PRIMA-1 stimulates eryptosis. Methods: Phosphatidylserine exposure at the cell surface was estimated from annexin V binding, cell volume from forward scatter, [Ca²⁺]_i from Fluo3-fluorescence, ceramide abundance from binding of specific antibodies, and ROS formation from DCFDA fluorescence. Results: A 48 h exposure of human erythrocytes to PRIMA-1 (25 µM) significantly increased the percentage of annexin-V-binding cells without significantly influencing [Ca²⁺]_i or forward scatter. PRIMA-1 (100 µM) induced annexin-V-binding was not significantly blunted by removal of extracellular Ca²⁺ or by the caspase-3 inhibitor zVAD. PRIMA-1 (100 µM) further increased the ceramide abundance at the cell surface and ROS formation. Conclusions: PRIMA-1 stimulates phosphatidylserine translocation at the erythrocyte cell membrane, an effect at least partially due to up-regulation of ceramide abundance and ROS formation.

Section: Discussionmentioning

confidence: 99%

Stimulation of Suicidal Erythrocyte Death by PRIMA-1

Faggio

Alzoubi

Calabrò

et al. 2015

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“…Moreover, eryptosis is triggered by activated casein kinase 1α, Janus-activated kinase JAK3, protein kinase C, p38 kinase, and PAK2 kinase [25], as well as by inhibited or lacking AMP activated kinase AMPK, cGMP-dependent protein kinase, sorafenib sensitive kinases and sunitinib sensitive kinases [25]. Stimulators of eryptosis further include diverse xenobiotics [25,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57]. …”

Section: Introductionmentioning

confidence: 99%

Stimulation of Suicidal Erythrocyte Death by the Antimalarial Drug Mefloquine

Bissinger

Barking

Alzoubi

et al. 2015

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Background: The antimalarial drug mefloquine has previously been shown to stimulate apoptosis of nucleated cells. Similar to apoptosis, erythrocytes may enter suicidal death or eryptosis, which is characterized by cell shrinkage and phospholipid scrambling of the erythrocyte cell membrane with phosphatidylserine translocation to the erythrocyte surface. Stimulators of eryptosis include oxidative stress, increase of cytosolic Ca²⁺-activity ([Ca²⁺]_i), and ceramide. Methods: Phosphatidylserine abundance at the cell surface was estimated from annexin V binding, cell volume from forward scatter, reactive oxidant species (ROS) from 2′,7′-dichlorodihydrofluorescein diacetate (DCFDA) fluorescence, [Ca²⁺]_i from Fluo3-fluorescence, and ceramide abundance from specific antibody binding. Results: A 48 h treatment of human erythrocytes with mefloquine significantly increased the percentage of annexin-V-binding cells (≥5 µg/ml), significantly decreased forward scatter (≥5 µg/ml), significantly increased ROS abundance (5 µg/ml), significantly increased [Ca²⁺]_i (7.5 µg/ml) and significantly increased ceramide abundance (10 µg/ml). The up-regulation of annexin-V-binding following mefloquine treatment was significantly blunted but not abolished by removal of extracellular Ca²⁺. Even in the absence of extracellular Ca²⁺, mefloquine significantly increased annexin-V-binding. Conclusions: Mefloquine treatment leads to erythrocyte shrinkage and erythrocyte membrane scrambling, effects at least partially due to induction of oxidative stress, increase of [Ca²⁺]_i and up-regulation of ceramide abundance.

“…Eryptosis is triggered by a myriad of xenobiotics [27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63] and enhanced eryptosis contributes to the pathophysiology of several clinical conditions including fever, malaria, sepsis, iron deficiency, malignancy, metabolic syndrome, diabetes, hepatic and renal insufficiency, hemolytic uremic syndrome, dehydration, hyperphosphatemia, phosphate depletion, sickle cell disease, thalassemia, glucose phosphate dehydrogenase deficiency and Wilson's disease [12,63,64,65]. …”

Section: Introductionmentioning

confidence: 99%

Programmed Erythrocyte Death Following in Vitro Treosulfan Treatment

Peter

Bissinger

Enkel

et al. 2015

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Background/Aims: The cytotoxic drug Treosulfan is clinically used for the treatment of malignancy. A common side effect of Treosulfan treatment is anemia. Treosulfan is at least partially effective by triggering apoptosis of tumor cells. Similar to apoptosis of nucleated cells, erythrocytes may enter eryptosis, a suicidal death characterized by cell shrinkage and translocation of phosphatidylserine from the inner to the outer leaflet of the plasma membrane. Triggers of eryptosis include oxidative stress, Ca²⁺-entry and increase of cytosolic Ca²⁺-activity ([Ca²⁺]_i). The present study explored whether Treosulfan stimulates eryptosis, which may contribute to development of anemia. Methods: Erythrocyte volume was estimated from forward scatter, phosphatidylserine abundance at the erythrocyte surface from Fluorescein isothiocyanate (FITC)-annexin-V-binding, [Ca²⁺]_i from Fluo3 fluorescence and reactive oxygen species (ROS) from 2',7'-dichlorodihydrofluorescein diacetate (DCFDA)-fluorescence. Results: A 48 hours exposure of human erythrocytes to Treosulfan (800 µg/ml) significantly decreased erythrocyte forward scatter, increased the percentage of annexin-V-binding cells, increased [Ca²⁺]_i, and increased ROS. The effect of Treosulfan on annexin-V-binding was virtually abrogated by removal of extracellular Ca²⁺. Conclusion: Treosulfan stimulates suicidal erythrocyte death or eryptosis at least in part by inducing oxidative stress and stimulating Ca²⁺ entry.