title: Neohesperidin dihydrochalcone down-regulates MyD88-dependent and -independent signaling by inhibiting endotoxin-induced trafficking of TLR4 to lipid rafts.
abstract: Fulminant hepatic failure (FHF) is a lethal clinical syndrome characterized by the activation of macrophages and the increased production of inflammatory mediators. The purpose of this study was to investigate the effects of neohesperidin dihydrochalcone (NHDC), a widely-used low caloric artificial sweetener against FHF. An FHF experimental model was established in mice by intraperitoneal injection of D-galactosamine (d-GalN) (400mg/kg)/lipopolysaccharides (LPS) (10 μg/kg). Mice were orally administered NHDC for 6 continuous days and at 1h before d-GalN/LPS administration. RAW264.7 macrophages were used as an in vitro model. Cells were pre-treated with NHDC for 1h before stimulation with LPS (10 μg/ml) for 6h. d-GalN/LPS markedly increased the serum transaminase activities and levels of oxidative and inflammatory markers, which were significantly attenuated by NHDC. Mechanistic analysis indicated that NHDC inhibited LPS-induced myeloid differentiation factor 88 (MyD88) and TIR-containing adapter molecule (TRIF)-dependent signaling. Transient transfection of TLR4 or MyD88 siRNA inhibited the downstream inflammatory signaling. This effect could also be achieved by the pretreatment with NHDC. The fluorescence microscopy and flow cytometry results suggested that NHDC potently inhibited the binding of LPS to TLR4 in RAW264.7 macrophages. In addition, the inhibitory effect of NHDC on LPS-induced translocation of TLR4 into lipid raft domains played an important role in the amelioration of production of downstream pro-inflammatory molecules. Furthermore, the activation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) by NHDC inhibited TLR4 signaling. In conclusion, our results suggest that NHDC attenuates d-GalN/LPS-induced FHF by inhibiting the TLR4-mediated inflammatory pathway, demonstrating a new application of NHDC as a hepatoprotective agent.
authors.affiliation: Key Laboratory of Luminescence and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Pharmaceutical Sciences, Southwest University, Chongqing, People's Republic of China, 400715.
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Xia
authors.affiliation: Key Laboratory of Luminescence and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Pharmaceutical Sciences, Southwest University, Chongqing, People's Republic of China, 400715.
authors.forename: Juanli
authors.initials: J
authors.lastname: Fu
authors.affiliation: Key Laboratory of Luminescence and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Pharmaceutical Sciences, Southwest University, Chongqing, People's Republic of China, 400715.
authors.forename: Xiufang
authors.initials: X
authors.lastname: Song
authors.affiliation: Key Laboratory of Luminescence and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Pharmaceutical Sciences, Southwest University, Chongqing, People's Republic of China, 400715.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Shi
authors.affiliation: Key Laboratory of Luminescence and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Pharmaceutical Sciences, Southwest University, Chongqing, People's Republic of China, 400715.
authors.forename: Chuanyang
authors.initials: C
authors.lastname: Su
authors.affiliation: Key Laboratory of Luminescence and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Pharmaceutical Sciences, Southwest University, Chongqing, People's Republic of China, 400715.
authors.forename: Erqun
authors.initials: E
authors.lastname: Song
authors.affiliation: Key Laboratory of Luminescence and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Pharmaceutical Sciences, Southwest University, Chongqing, People's Republic of China, 400715. Electronic address: songyangwenrong@hotmail.com.
authors.forename: Yang
authors.initials: Y
authors.lastname: Song
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D015153:Blotting, Western; D047188:Chalcones / Q000494:pharmacology*; D004195:Disease Models, Animal; D015536:Down-Regulation; D024202:Electrophoretic Mobility Shift Assay; D004731:Endotoxins / Q000378:metabolism*; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006569:Hesperidin / Q000031:analogs & derivatives* / Q000494:pharmacology; D007150:Immunohistochemistry; D017114:Liver Failure, Acute / Q000378:metabolism* / Q000473:pathology; D021962:Membrane Microdomains / Q000378:metabolism; D051379:Mice; D053594:Myeloid Differentiation Factor 88 / Q000378:metabolism; D021381:Protein Transport / Q000187:drug effects; D034741:RNA, Small Interfering / Q000235:genetics; D015398:Signal Transduction / Q000187:drug effects*; D013549:Sweetening Agents / Q000494:pharmacology; D051197:Toll-Like Receptor 4 / Q000378:metabolism*; D014162:Transfection
chemical_list: D000975:Antioxidants; D047188:Chalcones; D004731:Endotoxins; C507780:Myd88 protein, mouse; D053594:Myeloid Differentiation Factor 88; D034741:RNA, Small Interfering; D013549:Sweetening Agents; C493487:Tlr4 protein, mouse; D051197:Toll-Like Receptor 4; C013613:neohesperidin dihydrochalcone; D006569:Hesperidin
keywords: D-galactosamine; Endotoxin; Fulminant hepatic failure; Inflammation; Lipid raft; Lipopolysaccharide; MyD88; NF-κB; Nrf2; ROS; Toll-like receptor 4