Ca2+ Entry, Oxidative Stress, Ceramide and Suicidal Erythrocyte Death Following Diosgenin Treatment

Abstract

Background/Aims: The bioactive steroid sapogenin diosgenin is considered for a wide variety of applications including treatment of malignancy. The substance counteracts tumor growth in part by stimulating apoptosis of tumor cells. Similar to apoptosis of nucleated cells, erythrocytes may enter suicidal death or eryptosis, which is characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Signaling involved in the stimulation of eryptosis includes increase of cytosolic Ca²⁺ activity ([Ca²⁺]_i), oxidative stress and ceramide. The present study explored, whether diosgenin induces eryptosis and, if so, to decipher 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 DCF dependent fluorescence, and ceramide abundance utilizing specific antibodies. Hemolysis was quantified by determination of haemoglobin concentration in the supernatant. Results: A 48 hours exposure of human erythrocytes to diosgenin significantly increased the percentage of annexin-V-binding cells (≥ 5 µM), significantly decreased forward scatter (15 µM), significantly increased Fluo3-fluorescence (≥ 10 µM), significantly increased DCF fluorescence (15 µM), significantly increased ceramide abundance (15 µM) and significantly increased hemolysis (15 µM). The effect of diosgenin (15 µM) on annexin-V-binding was significantly blunted but not abolished by removal of extracellular Ca²⁺. Conclusions: Diosgenin stimulates eryptosis with erythrocyte shrinkage and phospholipid scrambling of the erythrocyte cell membrane, an effect paralleled by and at least in part due to Ca²⁺ entry, oxidative stress and ceramide.

Diosgenin, an Activator of 1,25D3-MARRS Receptor/ERp57, Attenuates the Effects of TNF-α by Causing ADAM10-Dependent Ectodomain Shedding of TNF Receptor 1

“…In human cortical neuron cells [17], erythrocytes [18] and mesenteric endothelial cells [19], diosgenin (10 µM, 15 µM or 1 mM, respectively) was shown to increase intracellular Ca 2+ concentration. In these studies [17, 18], diosgenin induced little or no change in intracellular Ca 2+ in Ca 2+ -free solution as in the present study. However, it was not clear how diosgenin induces extracellular Ca 2+ influx.…”

Oxidative stress, eryptosis and anemia: a pivotal mechanistic nexus in systemic diseases

“…Eryptosis may be induced by oxidative stress , which not only plays a crucial role in eryptosis‐related pathophysiology in several diseases but also contributes to its stimulation by a wide spectrum of xenobiotics . Oxidative stress is defined as an augmented production and/or a diminished elimination of reactive oxygen species (ROS) affecting the major cellular components such as DNA, lipids and proteins.…”

Increased eryptosis in smokers is associated with the antioxidant status and C-reactive protein levels

“…These events can be linked with atherosclerosis and cardiovascular disease since eryptotic erythrocytes adhere to endothelial cells of the vascular wall by interaction of phosphatidylserine exposed at the membrane surface with endothelial CXCL16 (Borst et al, 2012;Silva-Herdade et al, 2016), triggering blood clotting and thrombosis (Andrews and Low, 1999), thus interfering with microcirculation (Closse et al, 1999;Lang et al, 2013;Briglia et al, 2017). In addition, increase in ROS, hemolysis, lipid peroxidation, PGE-2 release and decrease in GSH are common features in oxidative stress-induced eryptosis (Bissinger et al, 2014;Mischitelli et al, 2016aMischitelli et al, , 2016bTesoriere et al, 2014;Álvarez-Sala et al, 2018).…”