title: Cytotoxic effects of incense particles in relation to oxidative stress, the cell cycle and F-actin assembly.
abstract: Epidemiological studies have suggested that combustion-derived smoke, such as that produced during incense burning, is a deleterious air pollutant. It is capable of initiating oxidative stress and mutation; however, the related apoptotic processes remain unclear. In order to elucidate the biological mechanisms of reactive oxygen species (ROS)-induced respiratory toxicology, alveolar epithelial A549 cells were exposed to incense particulate matter (PM), with and without antioxidant N-acetyl-l-cysteine (NAC). The cross-linking associations between oxidative capacity, cell cycle events, actin cytoskeletal dynamics and intracellular calcium signals were investigated. An incense PM suspension caused significant oxidative stress in A549 cells, as shown by inhibition of the cell cycle at G1 and G2/M check-points, and the induction of apoptosis at Sub-G1. At the same time, alterations in the F-actin filamentous assemblies were observed. The levels of intracellular Ca(2+) were increased after incense PM exposure. Antioxidant NAC treatment revealed that oxidative stress and F-actin remodelling was significantly mitigated. This suggests that ROS accumulation could alter cell cycle regulation and anomalous remodelling of the cortical cytoskeleton that allowed impaired cells to enter into apoptosis. This study has elucidated the integral patho-physiological interactions of incense PM and the potential mechanisms for the development of ROS-driven respiratory impairment.
authors.affiliation: School of Respiratory Therapy, College of Medicine, Taipei Medical University, Taipei, Taiwan. r92841005@ntu.edu.tw
authors.forename: Hsiao-Chi
authors.initials: HC
authors.lastname: Chuang
authors.forename: Tim
authors.initials: T
authors.lastname: Jones
authors.forename: Tzu-Tao
authors.initials: TT
authors.lastname: Chen
authors.forename: Kelly
authors.initials: K
authors.lastname: BéruBé
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D008841:Actin Cytoskeleton / Q000378:metabolism* / Q000648:ultrastructure; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D059447:Cell Cycle Checkpoints / Q000187:drug effects*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000502:physiology; D004847:Epithelial Cells / Q000187:drug effects / Q000473:pathology; D006801:Humans; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D018384:Oxidative Stress / Q000187:drug effects*; D052638:Particulate Matter / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism; D012140:Respiratory Tract Diseases / Q000139:chemically induced* / Q000378:metabolism
chemical_list: D052638:Particulate Matter; D017382:Reactive Oxygen Species; D000111:Acetylcysteine