title: Extracellular polysaccharide from Bacillus sp. strain LBP32 prevents LPS-induced inflammation in RAW 264.7 macrophages by inhibiting NF-κB and MAPKs activation and ROS production.
abstract: Extracellular polysaccharides (EPSs) are high-molecular weight sugar-based polymers that are synthesized and secreted by many microorganisms. Recently, EPSs have attracted particular attention due to their multiple biological functions including anti-inflammation. However, studies rarely reported the molecular mechanisms underlying their functions. We previously purified an EPS from an oligotrophic bacteria (Bacillus sp. LBP32) found in Lop Nur Desert, which possesses a potent antioxidant activity, while the anti-inflammatory effects of EPS and signaling mechanisms underlying its action have not been clarified. In this study, we demonstrated that EPS significantly inhibited the LPS-induced release of pro-inflammatory mediators, such as nitric oxide (NO), IL-6 and TNF-α, without any significant cytotoxicity. EPS also downregulated the expression of nitric oxide synthase (iNOS) induced by LPS. Furthermore, activation of nuclear factor κB (NF-κB) was abrogated by EPS through inhibited the phosphorylation of IκB kinase (IKK). Activations of Mitogen-activated protein kinases (MAPKs), including p38 MAPK and c-Jun N-terminal kinase (JNK), were also found to be inhibited by EPS. In addition, the level of intracellular reactive oxygen species (ROS) was also significantly decreased with the treatment of EPS. In vivo experiments were conducted and showed that EPS could greatly improve the outcome of mice with LPS-induced endotoxic shock. Taken together, our data indicate that EPS prevents LPS-induced inflammatory response by inhibiting NF-κB and MAPKs activation and ROS production.
authors.affiliation: Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, Jiangsu, PR China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Diao
authors.affiliation: Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, Jiangsu, PR China.
authors.forename: Yinqiang
authors.initials: Y
authors.lastname: Xin
authors.affiliation: Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, Jiangsu, PR China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, Jiangsu, PR China.
authors.forename: Na
authors.initials: N
authors.lastname: Li
authors.affiliation: Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, Jiangsu, PR China.
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Pan
authors.affiliation: Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, Jiangsu, PR China.
authors.forename: Shimei
authors.initials: S
authors.lastname: Qi
authors.affiliation: Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, Jiangsu, PR China.
authors.forename: Zhilin
authors.initials: Z
authors.lastname: Qi
authors.affiliation: Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, Jiangsu, PR China.
authors.forename: Yimiao
authors.initials: Y
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, PR China; Collaborative Innovation Center of Biomedicine for Public Hygiene Emergency and Critical Care, Jiangsu Life Sciences & Technology Innovation Park, Nanjing, Jiangsu, PR China.
authors.forename: Lan
authors.initials: L
authors.lastname: Luo
authors.affiliation: College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing 210-009, PR China; Collaborative Innovation Center of Biomedicine for Public Hygiene Emergency and Critical Care, Jiangsu Life Sciences & Technology Innovation Park, Nanjing, Jiangsu, PR China. Electronic address: hg_wan@yahoo.cn.
authors.forename: Honggui
authors.initials: H
authors.lastname: Wan
authors.affiliation: Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, Jiangsu, PR China; Collaborative Innovation Center of Biomedicine for Public Hygiene Emergency and Critical Care, Jiangsu Life Sciences & Technology Innovation Park, Nanjing, Jiangsu, PR China. Electronic address: lanlei1978@gmail.com.
authors.forename: Lei
authors.initials: L
authors.lastname: Lan
authors.affiliation: Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, Jiangsu, PR China; Collaborative Innovation Center of Biomedicine for Public Hygiene Emergency and Critical Care, Jiangsu Life Sciences & Technology Innovation Park, Nanjing, Jiangsu, PR China. Electronic address: yinzhimin@njnu.edu.cn.
authors.forename: Zhimin
authors.initials: Z
authors.lastname: Yin
mesh_terms: D000818:Animals; D001407:Bacillus / Q000276:immunology* / Q000472:pathogenicity; D002460:Cell Line; D015536:Down-Regulation; D019446:Endotoxemia / Q000276:immunology*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D016908:Gram-Positive Bacterial Infections / Q000276:immunology*; D007165:Immunosuppression Therapy; D018836:Inflammation Mediators / Q000378:metabolism; D008264:Macrophages / Q000276:immunology* / Q000382:microbiology; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism; D011135:Polysaccharides, Bacterial / Q000276:immunology / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction; D015533:Transcriptional Activation; D037521:Virulence Factors / Q000276:immunology / Q000378:metabolism*
chemical_list: D018836:Inflammation Mediators; D016328:NF-kappa B; D011135:Polysaccharides, Bacterial; D017382:Reactive Oxygen Species; D037521:Virulence Factors; D048049:Extracellular Signal-Regulated MAP Kinases
keywords: ASK1; EPS; Inflammation; MAPKs; NF-κB; ROS