title: AFM visualization of cortical filaments/network under cell-bound membrane vesicles.
abstract: While circulating/plasma membrane vesicles have been extensively characterized, due to the lack of effective methods cell-bound membrane vesicles are poorly understood including their shape and correlation with the intracellular cytoskeleton. In this study, we focused on cell-bound membrane vesicles and individual vesicle-derived pits on endothelial cells by using confocal microscopy and atomic force microscopy (AFM). For the first time, we found that cell-bound membrane vesicles are hemisphere-shaped and that the actin cortical filaments/network lies at the cytosolic opening of a vesicle instead of being closely attached to the inner side of the vesicle membrane. This structure of cell-bound membrane vesicles may be beneficial to their movement in, or release from, the plasma membrane of cells due to less membrane-cytoskeleton coupling to be broken therefore probably minimizing energy consumption and time usage. Further study indicates that TNF-α activation induced a significant increase in average number/size of cell-bound vesicles and the local disruption of the actin network at the cytosolic opening of cell-bound vesicles.
authors.affiliation: Nanoscale Science and Technology Laboratory, Institute for Advanced Study, Nanchang University, Nanchang, Jiangxi 330031, P. R. China.
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Nanoscale Science and Technology Laboratory, Institute for Advanced Study, Nanchang University, Nanchang, Jiangxi 330031, P. R. China.
authors.forename: Qisheng
authors.initials: Q
authors.lastname: Tang
authors.affiliation: School of Basic Medical Sciences, Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi 330025, P. R. China.
authors.forename: Li
authors.initials: L
authors.lastname: Wu
authors.affiliation: The Third Hospital of Jiujiang, Jiujiang, Jiangxi 332000, P. R. China.
authors.forename: Jie
authors.initials: J
authors.lastname: Huang
authors.affiliation: Nanoscale Science and Technology Laboratory, Institute for Advanced Study, Nanchang University, Nanchang, Jiangxi 330031, P. R. China. Electronic address: dr_yongchen@hotmail.com.
authors.forename: Yong
authors.initials: Y
authors.lastname: Chen
mesh_terms: D008841:Actin Cytoskeleton / Q000187:drug effects / Q000648:ultrastructure*; D002462:Cell Membrane / Q000187:drug effects / Q000648:ultrastructure*; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000187:drug effects / Q000648:ultrastructure*; D006801:Humans; D008560:Membrane Fluidity / Q000187:drug effects; D018625:Microscopy, Atomic Force / Q000379:methods*; D022161:Transport Vesicles / Q000187:drug effects / Q000648:ultrastructure*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D014409:Tumor Necrosis Factor-alpha
keywords: Atomic force microscopy (AFM); Cortical filaments/network; Endothelial cells; Membrane vesicles; TNF-α; Vesicle-derived pits