Busulfan Triggers Intrinsic Mitochondrial-Dependent Platelet Apoptosis Independent of Platelet Activation.
As a nonspecific alkylating antineoplastic agent, busulfan has been widely used in the treatment of patients with chronic myeloid leukemia. In vitro and in vivo studies demonstrated busulfan-induced cell apoptosis. Whether busulfan triggers platelet apoptosis remains unclear. This study aimed to evaluate the role of busulfan in platelet apoptosis. Isolated human platelets were incubated with busulfan followed by analysis of platelet apoptosis by flow cytometry or western blot, including mitochondrial depolarization, expression of Bcl-2, and Bax and caspase 3 activation. Meanwhile, platelet activation, expression of glycoprotein Ibα (GPIbα), glycoprotein VI (GPVI), and <alpha>IIb<beta>3 and platelet aggregation in response to collagen and adenosine diphosphate (ADP) were measured. Additionally, busulfan was injected into mice with or without administration of caspase inhibitor QVD-Oph to investigate its effect on platelet lifespan. Our results showed that busulfan-treated platelets displayed increased mitochondrial membrane depolarization, decreased expression of Bcl-2, increased expression of Bax and caspase 3 activation in dose-dependent manner, which were inhibited by QVD-Oph. Platelet activation was not observed in busulfan-treated platelets as showed by no increased P-selectin expression and PAC-1 binding. However, busulfan reduced collagen- or ADP-induced platelet aggregation without affecting expression of GPIbα, GPVI, and <alpha>IIb<beta>3. Furthermore, busulfan reduced circulating platelet lifespan which was ameliorated by QVD-Oph in mice. In conclusion, busulfan triggers mitochondrial-dependent platelet apoptosis and reduces platelet lifespan in mice. These data suggest targeting caspase activation might be beneficial in the prophylaxis of platelet apoptosis-associated thrombocytopenia after administration of busulfan.
Blood Diseases Institute, Xuzhou Medical University, Xuzhou 221002, China; Department of Hematology, The Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, China; Key Laboratory of Bone Marrow Stem Cell, Xuzhou, Jiangsu Province 221002, China.
Jianlin
J
Qiao
Blood Diseases Institute, Xuzhou Medical University, Xuzhou 221002, China; Key Laboratory of Bone Marrow Stem Cell, Xuzhou, Jiangsu Province 221002, China.
Yulu
Y
Wu
Department of Clinical Laboratory, The Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, China.
Yun
Y
Liu
Blood Diseases Institute, Xuzhou Medical University, Xuzhou 221002, China; Key Laboratory of Bone Marrow Stem Cell, Xuzhou, Jiangsu Province 221002, China.
Xiaoqian
X
Li
Blood Diseases Institute, Xuzhou Medical University, Xuzhou 221002, China; Key Laboratory of Bone Marrow Stem Cell, Xuzhou, Jiangsu Province 221002, China.
Xiaoqing
X
Wu
Department of Hematology, Tengzhou Central People's Hospital, Tengzhou 277500, China.
Na
N
Liu
Department of Hematology, The Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, China.
Feng
F
Zhu
Department of Hematology, The Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, China.
Kunming
K
Qi
Department of Hematology, The Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, China.
Hai
H
Cheng
Department of Hematology, The Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, China.
Depeng
D
Li
Department of Clinical Laboratory, The Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, China.
Hongchun
H
Li
Department of Hematology, The Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, China.
Zhenyu
Z
Li
Blood Diseases Institute, Xuzhou Medical University, Xuzhou 221002, China; Department of Hematology, The Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, China; Key Laboratory of Bone Marrow Stem Cell, Xuzhou, Jiangsu Province 221002, China.
Lingyu
L
Zeng
Department of Clinical Laboratory, The Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, China. Electronic address: pingm62@aliyun.com.
Ping
P
Ma
Blood Diseases Institute, Xuzhou Medical University, Xuzhou 221002, China; Department of Hematology, The Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, China; Key Laboratory of Bone Marrow Stem Cell, Xuzhou, Jiangsu Province 221002, China. Electronic address: lihmd@163.com.
Kailin
K
Xu
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001792:Blood Platelets / Q000166:cytology*; D002066:Busulfan / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D051379:Mice; D008928:Mitochondria / Q000502:physiology*; D015539:Platelet Activation
D002066:Busulfan
Apoptosis; Busulfan; Mitochondrion; Platelet activation; Platelets