title: Macrophage apoptosis induced by aqueous C60 aggregates changing the mitochondrial membrane potential.
abstract: Fullerenes have been applied to various fields in recent years for their unique physicochemical properties. C60's potential environmental and health risks are therefore being investigated. This work presents the cytotoxicity of aqueous C60 aggregates (nC60) by using the mouse peritoneal macrophage (RAW264.7) as a model biological system. Cells incubated with nC60 showed a decrease in cell viability, and the quantities of cell apoptosis increased significantly in a dose-dependent and time-dependent manner. By TEM imaging cells were observed to be asymmetric and shrunken compared to control cells. nC60 was adsorbed onto the plasma membrane and apparent phagocytosis was observed after a 24h exposure. The intracellular reactive oxygen species (ROS) were quantified with the dichlorofluorescein diacetate (DCFH-DA) detection assay kit by flow cytometry and found to increase in treated cells. Membrane damage and lipid peroxidation were not observed, since both intracellular and extracellular MDA showed no variation. Detection of the mitochondrial membrane potential (MMP) by JC-1 assay kit showed that MMP had an obvious dose-dependent loss. We speculate that the nC60 aggregates induced apoptosis of macrophage by changing the mitochondrial membrane potential.
authors.affiliation: School of Environmental Science & Engineering, Shanghai Jiaotong University, 800 Dongchuan Road, Shanghai 200240, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang
authors.affiliation: School of Environmental Science & Engineering, Shanghai Jiaotong University, 800 Dongchuan Road, Shanghai 200240, China.
authors.forename: Weilin
authors.initials: W
authors.lastname: Bian
authors.affiliation: Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, E1A 07-03, Singapore 117576, Singapore.
authors.forename: Amrita
authors.initials: A
authors.lastname: Pal
authors.affiliation: School of Environmental Science & Engineering, Shanghai Jiaotong University, 800 Dongchuan Road, Shanghai 200240, China. Electronic address: ylhe@sjtu.edu.cn.
authors.forename: Yiliang
authors.initials: Y
authors.lastname: He
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D037741:Fullerenes / Q000633:toxicity*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D017737:Macrophages, Peritoneal / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects*; D051379:Mice; D046529:Microscopy, Electron, Transmission; D009336:Necrosis / Q000139:chemically induced; D017382:Reactive Oxygen Species / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
chemical_list: D037741:Fullerenes; D017382:Reactive Oxygen Species; D017392:Thiobarbituric Acid Reactive Substances; D007770:L-Lactate Dehydrogenase; C069837:fullerene C60
keywords: Apoptosis; Lipid peroxidation; Mitochondrial membrane potential; nC(60)