title: The role of intraplatelet reactive oxygen species in the regulation of platelet glycoprotein Ibα ectodomain shedding.
abstract: Glycoprotein (GP) Ibα ectodomain shedding has become a generally accepted negative regulatory mechanism of platelet function. Stimulation of platelet with either physiological or chemical compound results in GPIbα ectodomain shedding in vitro and in vivo, the mechanism, however, is not totally understood. Here we show, collagen, thrombin, and calcium ionophore A23187 induce reactive oxygen species (ROS) generation, and simultaneously incur GPIbα ectodomain shedding. ROS scavengers N-acetylcysteine (NAC) and dithiothreitol (DTT) abolish not only collagen, thrombin, and A23187 induced ROS production, but also GPIbα ectodomain shedding. Interestingly, a recognized calpain activator, dibucaine, induces both ROS production and GPIbα shedding, which are also obviously reduced by NAC and DTT. Furthermore, calpain inhibitors calpain inhibitor I and carbobenzoxy-valinyl-phenylalaninal, obviously reduce dibucaine, thrombin, and A23187-induced ROS generation. These data indicate that ROS plays a key role in collagen, thrombin, and A23187-induced GPIbα ectodomain shedding. Calpain is an up-stream regulator that regulates ROS-mediated GPIbα shedding.
authors.affiliation: Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Suzhou, China; Department of Hematology, the First Affiliated Hospital of Bengbu medical college, Bengbu, China.
authors.forename: Pingping
authors.initials: P
authors.lastname: Zhang
authors.forename: Juan
authors.initials: J
authors.lastname: Du
authors.forename: Lili
authors.initials: L
authors.lastname: Zhao
authors.forename: Xiujuan
authors.initials: X
authors.lastname: Wang
authors.forename: Yiwen
authors.initials: Y
authors.lastname: Zhang
authors.forename: Rong
authors.initials: R
authors.lastname: Yan
authors.forename: Jin
authors.initials: J
authors.lastname: Dai
authors.forename: Guanglei
authors.initials: G
authors.lastname: Liu
authors.forename: Feng
authors.initials: F
authors.lastname: Zhang
authors.forename: Kesheng
authors.initials: K
authors.lastname: Dai
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D000001:Calcimycin / Q000494:pharmacology; D002154:Calpain / Q000037:antagonists & inhibitors / Q000097:blood; D003094:Collagen / Q000494:pharmacology; D004229:Dithiothreitol / Q000494:pharmacology; D005434:Flow Cytometry; D006801:Humans; D019038:Platelet Glycoprotein GPIb-IX Complex / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013917:Thrombin / Q000494:pharmacology
chemical_list: D019038:Platelet Glycoprotein GPIb-IX Complex; D017382:Reactive Oxygen Species; D000001:Calcimycin; D003094:Collagen; D013917:Thrombin; D002154:Calpain; D004229:Dithiothreitol; D000111:Acetylcysteine
keywords: 6-carboxy-2’,7’-dichlorodihydrofluorescein diacetate; ACD; ADAM17; ANOVA; CI I; Calpain; DCF; DCFH; DCFH-DA; DMSO; DTT; FITC; GC; GP; Glycoprotein Ibα; MDL; N-(6-aminohexyl)-5-chloro-1-naphthalene sulfonamide; N-acetylcysteine; N-ethylmaleimide; NAC; NEM; PMA; Platelets; ROS; RT; Reactive oxygen species (ROS); Shedding; VWF; W7; a disintegrin and metalloproteinase 17; acid-citratedextrose; calpain inhibitors I; carbobenzoxy-valinyl-phenylalaninal; dichlorofluorescein; dimethyl sulfoxide; dithiothreitol; fluorescein isothiocyanate; glycocalicin; glycoprotein; non-fluorescent compound dichlorofluorescein; one-way analysis of variance; phorbol 12-myristate-13-acetate; reactive oxygen species; room temperature; von Willebrand factor