title: Cordycepin induced eryptosis in mouse erythrocytes through a Ca2+-dependent pathway without caspase-3 activation.
abstract: Cordyceps sinensis is a prized traditional Chinese medicine and its major component cordycepin is found to have anti-leukemia activities. However, its cytotoxicity in erythrocytes was unclear. To examine the effect of cordycepin on the induction of eryptosis (an apoptosis-like process in enucleated erythrocytes), flow cytometric assays based on membrane integrity and asymmetry were employed. For comparison, analyses were performed in parallel with two other anti-leukemia agents, indirubin 3'-monoxime (IDM) and As2O3. We found that at the IC50 against leukemia HL-60, cordycepin elicited eryptosis while IDM and As2O3 showed no erythrotoxicity in mouse erythrocytes. Mechanistically, cordycepin increased the [Ca2+]i and activated mu-calpain protease in a dose-dependent manner. Yet, no caspase-3 activation was observed in the cordycepin-treated erythrocytes. When extracellular Ca2+ was depleted, both the cordycepin-induced eryptosis and mu-calpain cleavage were suppressed. Our study therefore demonstrated for the first time that cordycepin induces eryptosis through a calcium-dependent pathway in the absence of mitochondria and caspase-3 activation.
authors.affiliation: Department of Biochemistry, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
authors.forename: Julian C K
authors.initials: JC
authors.lastname: Lui
authors.forename: Judy W Y
authors.initials: JW
authors.lastname: Wong
authors.forename: Y K
authors.initials: YK
authors.lastname: Suen
authors.forename: T T
authors.initials: TT
authors.lastname: Kwok
authors.forename: K P
authors.initials: KP
authors.lastname: Fung
authors.forename: S K
authors.initials: SK
authors.lastname: Kong
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000633:toxicity; D017209:Apoptosis / Q000187:drug effects*; D000077237:Arsenic Trioxide; D001152:Arsenicals; D015153:Blotting, Western; D000001:Calcimycin / Q000633:toxicity; D002118:Calcium / Q000378:metabolism*; D053148:Caspase 3 / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D003839:Deoxyadenosines / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D004912:Erythrocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D005434:Flow Cytometry; D018922:HL-60 Cells; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D007211:Indoles / Q000633:toxicity; D007424:Intracellular Fluid / Q000187:drug effects / Q000378:metabolism; D007476:Ionophores / Q000633:toxicity; D051379:Mice / Q000097:blood; D008807:Mice, Inbred BALB C; D010087:Oxides / Q000633:toxicity; D010091:Oximes / Q000633:toxicity
chemical_list: D000970:Antineoplastic Agents; D001152:Arsenicals; D003839:Deoxyadenosines; D007211:Indoles; D007476:Ionophores; D010087:Oxides; D010091:Oximes; C474021:indirubin-3'-monoxime; D000001:Calcimycin; D053148:Caspase 3; C058120:cordycepin; D000077237:Arsenic Trioxide; D002118:Calcium