Triggering of Suicidal Erythrocyte Death by Fascaplysin

Abstract

Background/Aims: The bis-indole alkaloid Fascaplysin is effective against malignancy, an effect at least partially due to stimulation of tumor cell apoptosis. Similar to apoptosis of nucleated cells, erythrocytes could 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 Fascaplysin induces eryptosis and, if so, to shed light on the cellular mechanisms involved. Methods: Flow cytometry was employed to estimate phosphatidylserine exposure at the cell surface from annexin-V-binding, cell volume from forward scatter, [Ca²⁺]_i from Fluo3-fluorescence, ROS formation from DCFDA dependent fluorescence, and ceramide abundance utilizing specific antibodies. Hemolysis was quantified from the hemoglobin concentration in the supernatant. Results: A 48 hours exposure of human erythrocytes to Fascaplysin (≥ 5 µM) significantly increased the percentage of annexin-V-binding cells, significantly decreased forward scatter, and significantly increased Fluo3-fluorescence, DCFDA fluorescence as well as ceramide abundance. The effect of Fascaplysin on annexin-V-binding and forward scatter was significantly blunted but not abolished by removal of extracellular Ca²⁺. Conclusions: Fascaplysin triggers cell shrinkage and phospholipid scrambling of the erythrocyte cell membrane, an effect at least in part due to Ca²⁺ entry, oxidative stress and ceramide.

Association of Diesel Exhaust Particle Exposure With Erythrocytes Deformation of Male Mice

“…In addition to the cell alteration, the deformation of the mice erythrocytes can be linked to the cell physical alteration (Yoon and You, 2016) and the existence of eryptosis, suicidal death erythrocytes (Mischitelli et al, 2016). Consistent with this assessment, we found that deformation level, as well as the deformed erythrocytes, were significantly increased in the mice exposed to the ultrafine particles.…”

“…Consistent with this result, erythrocytes are highly deformable and may also exhibit reduced deformability and stronger aggregation in many pathological situations, such as sickle cell anemia (Popel and Johnson, 2005). Eryptosis itself can be triggered by any kind of erythrocyte injury, including oxidative stress due to reactive oxygen species (Mischitelli et al, 2016). This deformation effect is likely to be due to the continuous exposure of diesel exhaust particles which alter the lipid bilayer.…”

Methods Employed in Cytofluorometric Assessment of Eryptosis, the Suicidal Erythrocyte Death

“…Examples are provided by treatment of erythrocytes with the CDC25B phosphatase inhibitor NSC-95397 [35], the PLK1 kinase inhibitor BI-2536 [89], the protease inhibitor Lopinavir [22], the marine sponge-derived Fascaplycin [44], the selective histamine H1 receptor antagonist Terfenadine [58] and Fucoxanthin (a carotenoid from the chloroplasts of brown seaweeds) [25]. In parallel examples of substances interfering with eryptosis signalling, such as caspase inhibitor Z-VAD-FMK, p38 inhibitor SB203580, protein kinase C inhibitor staurosporine and casein kinase 1 CK1α inhibitor D4476 [9] are provided.…”

Fascaplysin Derivatives Are Potent Multitarget Agents against Alzheimer’s Disease: in Vitro and in Vivo Evidence

“…Fascaplysin is a fused benzoyl-linked β-carboline alkaloid first obtained from the marine sponge Fascaplysinopsis bergquist near the Fiji islands in 1988 . Fascaplysin can inhibit cyclin-dependent kinase 4 to prevent ovarian cancer cell proliferation and metastasis and can increase suicidal erythrocyte death. − Moreover, fascaplysin was reported to inhibit AChE with IC 50 around 1.5 μM, suggesting that this compound might be used to treat AD . Recently, it was reported that fascaplysin could preferentially prevent Aβ aggregation and protect against Aβ oligomer-induced neuronal death .…”