title: Wear Particles Impair Antimicrobial Activity Via Suppression of Reactive Oxygen Species Generation and ERK1/2 Phosphorylation in Activated Macrophages.
abstract: Implant-related infection (IRI) is closely related to the local immunity of peri-implant tissues. The generation of reactive oxygen species (ROS) in activated macrophages plays a prominent role in the innate immune response. In previous studies, we indicated that implant wear particles promote endotoxin tolerance by decreasing the release of proinflammatory cytokines. However, it is unclear whether ROS are involved in the damage of the local immunity of peri-implant tissues. In the present study, we assessed the mechanism of local immunosuppression using titanium (Ti) particles and/or lipopolysaccharide (LPS) to stimulate RAW 264.7 cells. The results indicate that the Ti particles induced the generation of a moderate amount of ROS through nicotinamide adenine dinucleotide phosphate oxidase-1, but not through catalase. Pre-exposure to Ti particles inhibited ROS generation and extracellular-regulated protein kinase activation in LPS-stimulated macrophages. These findings indicate that chronic stimulation by Ti particles may lead to a state of oxidative stress and persistent inflammation, which may result in the attenuation of the immune response of macrophages to bacterial components such as LPS. Eventually, immunosuppression develops in peri-implant tissues, which may be a risk factor for IRI.
authors.affiliation: Department of Orthopaedic Surgery, The First Affiliated Hospital of Sun Yat-sen University, #58 Zhongshan 2nd Road, Guangzhou, 510080, China.
authors.forename: Weishen
authors.initials: W
authors.lastname: Chen
authors.forename: Ziqing
authors.initials: Z
authors.lastname: Li
authors.forename: Ying
authors.initials: Y
authors.lastname: Guo
authors.forename: Yuhuan
authors.initials: Y
authors.lastname: Zhou
authors.forename: Yangchun
authors.initials: Y
authors.lastname: Zhang
authors.forename: Guotian
authors.initials: G
authors.lastname: Luo
authors.forename: Xing
authors.initials: X
authors.lastname: Yang
authors.forename: Chaohong
authors.initials: C
authors.lastname: Li
authors.forename: Weiming
authors.initials: W
authors.lastname: Liao
authors.forename: Puyi
authors.initials: P
authors.lastname: Sheng
mesh_terms: D000818:Animals; D019643:Arthroplasty, Replacement / Q000009:adverse effects; D002374:Catalase / Q000378:metabolism; D002460:Cell Line; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D007113:Immunity, Innate; D007249:Inflammation / Q000276:immunology; D008070:Lipopolysaccharides / Q000276:immunology; D008262:Macrophage Activation / Q000276:immunology*; D008264:Macrophages / Q000276:immunology*; D051379:Mice; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism; D000074624:NADPH Oxidase 1; D018384:Oxidative Stress; D010766:Phosphorylation; D019736:Prostheses and Implants / Q000009:adverse effects*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D014025:Titanium / Q000276:immunology
chemical_list: D008070:Lipopolysaccharides; D017382:Reactive Oxygen Species; D014025:Titanium; D002374:Catalase; D009247:NADH, NADPH Oxidoreductases; D000074624:NADPH Oxidase 1; D048049:Extracellular Signal-Regulated MAP Kinases