title: The disintegrin, trimucrin, suppresses LPS-induced activation of phagocytes primarily through blockade of NF-κB and MAPK activation.
abstract: In addition to antiplatelet activity, disintegrin, a small-mass RGD-containing polypeptide, has been shown to exert anti-inflammatory effects but the mechanism involved remains unclear. In this study, we report that trimucrin, a disintegrin from the venom of Trimeresurus mucrosquamatus, inhibits lipopolysaccharide (LPS)-induced stimulation of THP-1 and RAW 264.7 cells. We also investigate the underlying mechanism. Trimucrin decreased the release of proinflammatory cytokines including tumor necrosis factor α (TNFα), interleukin-6 (IL-6), nitric oxide, and reactive oxygen species (ROS), and inhibited the adhesion and migration of LPS-activated phagocytes. Trimucrin significantly blocked the expression of nuclear factor kappaB (NF-κB)-related downstream inducible enzymes such as inducible nitric oxide synthase (iNOS) and COX-2. In addition, its anti-inflammatory effect was associated with the decreased mitogen-activated protein kinase (MAPK) phosphorylation. Furthermore, trimucrin concentration dependently inhibited LPS-induced phosphorylation of focal adhesion kinase (FAK), PI3K, and Akt. Trimucrin also reversed the DNA-binding activity of NF-κB by suppressing the LPS-induced nuclear translocation of p65 and the cytosolic IκB release. Flow cytometric analyses showed that trimucrin bound to cells in a concentration-dependent manner. The anti-αVβ3 mAb also specifically decreased the binding of fluorescein isothiocyanate (FITC)-conjugated trimucrin. Binding assays demonstrated that integrin αVβ3 was the binding site for trimucrin on THP-1 and RAW 264.7 cells. In conclusion, we showed that trimucrin decreases the inflammatory reaction through the attenuation of iNOS expression and nitric oxide (NO) production by blocking MAP kinase and the NF-κB activation in LPS-stimulated THP-1 and RAW 264.7 cells.
authors.affiliation: Graduate Institute of Pharmacology, College of Medicine, National Taiwan University, No1, Sec1, Jen-Ai Rd, Taipei, Taiwan.
authors.forename: Yu-Chun
authors.initials: YC
authors.lastname: Hung
authors.affiliation: Graduate Institute of Pharmacology, College of Medicine, National Taiwan University, No1, Sec1, Jen-Ai Rd, Taipei, Taiwan.
authors.forename: Chun-Chieh
authors.initials: CC
authors.lastname: Hsu
authors.affiliation: Department of Medicine, Mackay Medical College, New Taipei, Taiwan.
authors.forename: Ching-Hu
authors.initials: CH
authors.lastname: Chung
authors.affiliation: Graduate Institute of Pharmacology, College of Medicine, National Taiwan University, No1, Sec1, Jen-Ai Rd, Taipei, Taiwan. turfu@ntu.edu.tw.
authors.forename: Tur-Fu
authors.initials: TF
authors.lastname: Huang
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D001665:Binding Sites; D002448:Cell Adhesion / Q000187:drug effects; D045744:Cell Line, Tumor; D002633:Chemotaxis / Q000187:drug effects; D003435:Crotalid Venoms / Q000737:chemistry*; D051546:Cyclooxygenase 2 / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism; D019483:Disintegrins / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D039302:Integrin alphaVbeta3 / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology*; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D010455:Peptides / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D010586:Phagocytes / Q000187:drug effects* / Q000201:enzymology; D010766:Phosphorylation; D011485:Protein Binding; D000067996:RAW 264.7 Cells; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D000893:Anti-Inflammatory Agents; D003435:Crotalid Venoms; D016207:Cytokines; D019483:Disintegrins; D018836:Inflammation Mediators; D039302:Integrin alphaVbeta3; D008070:Lipopolysaccharides; D016328:NF-kappa B; D010455:Peptides; C029748:Trimeresurus venoms; C089139:trimucrin; D009569:Nitric Oxide; C496319:NOS2 protein, human; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; C077623:Ptgs2 protein, mouse; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D020928:Mitogen-Activated Protein Kinases
keywords: Integrin αVβ3; LPS; Phagocyte; Signaling transduction; Snake venom disintegrin