title: Inhibitory effects of simvastatin on staphylococcus aureus lipoteichoic acid-induced inflammation in human alveolar macrophages.
abstract: Staphylococcus aureus (S. aureus) is the most common bacterium in sepsis and pneumonia involving gram-positive bacteria. Lipoteichoic acid (LTA) is a cell wall component of gram-positive bacteria. It is a potent inducer of inflammatory mediators in human dendritic cells, human pulmonary epithelial cells, and murine macrophages. However, the effect of LTA on human alveolar macrophages (AMs) which are the major effector cells in host defense against respiratory tract infections has hardly been studied. Statins have anti-inflammatory, immunomodulatory, antioxidative, anticoagulant, and antibacterial activities. These effects may be contributed to reduce the markers of systemic inflammation. Emerging retrospective studies have demonstrated that statin use decreased the mortality of pneumonia. However, the precise mechanisms responsible for these effects are unclear. The purpose of this study is to define the role of S. aureus LTA in human AMs and the effects of simvastatin (SV) on LTA-stimulated human AMs. The results showed that LTA induced tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β), IL-8 mRNA expression, and suppressed IL-10 mRNA expression in human AMs. Simultaneously, LTA induced human AMs apoptosis. These effects were parallel with the up-regulation of the expression of NF-κB-P65 protein in the LTA-stimulated human AMs. The above effects of LTA on human AMs were inhibited significantly by SV. These data indicate that S. aureus LTA induces potent pro-inflammatory and pro-apoptotic effects on human AMs and statins exert anti-inflammatory effects by mediating inhibition of NF-κB activation and cytokine mRNA expression in human AMs. These results may explain, in part, the mechanisms responsible for favorable effects of statins on pneumonia.
authors: Department of Internal Medicine, Medical Intensive Care Unit and Division of Respiratory Diseases, Institute of Respiratory Disease and the Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510630, People's Republic of China, zswbq@163.com.
authors: Ben-Quan
authors: BQ
authors: Wu
authors: Jin-Mei
authors: JM
authors: Luo
authors: Yan-Hong
authors: YH
authors: Wang
authors: Yun-Feng
authors: YF
authors: Shi
authors: Hui
authors: H
authors: Liu
authors: Jun-Hui
authors: JH
authors: Ba
authors: Tian-Tuo
authors: TT
authors: Zhang
mesh_terms: D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis; D020869:Gene Expression Profiling; D006801:Humans; D008070:Lipopolysaccharides / Q000276:immunology*; D016676:Macrophages, Alveolar / Q000187:drug effects* / Q000276:immunology*; D019821:Simvastatin / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000276:immunology*; D013682:Teichoic Acids / Q000276:immunology*
chemical_list: D000893:Anti-Inflammatory Agents; D016207:Cytokines; D008070:Lipopolysaccharides; D013682:Teichoic Acids; C009900:lipoteichoic acid; D019821:Simvastatin