title: (5R)-5-Hydroxytriptolide (LLDT-8) inhibits osteoclastogenesis via RANKL/RANK/OPG signaling pathway.
abstract: BACKGROUND
  The aim of this study was to investigate the regulative activity of (5R)-5-hydroxytriptolide (LLDT-8) on receptor activator of nuclear factor κ-B ligand (RANKL)/receptor activator of nuclear factor κ-B (RANK)/Osteoprotegerin (OPG) system in rheumatoid arthritis (RA) and its anti-osteoclastogenesis mechanism.
  
  
  METHODS
  The expression of OPG, RANK and RANKL in CD3(+) T leukomonocytes in both peripheral blood and synovial fluid of RA patients was evaluated by flow cytometry. The levels of interleukin (IL) 1β, IL-6, IL-10, IL-21 and IL-23 in the supernatants of peripheral blood mononuclear cells (PBMCs) and synovial fluid mononuclear cells (SFMCs) were assayed by ELISA. Tartaric acid phosphatase (TRAP) staining was used to identify the osteoclast-like cells derived from RAW264.7. Western blotting analysis was used to check the downstream molecules of RANKL.
  
  
  RESULTS
  LLDT-8 increased the rate of OPG expression in CD3(+) T leukomonocytes in peripheral blood as well as the ratio of OPG/RANKL in both peripheral blood and synovial fluid. LLDT-8 inhibited IL-1β, IL-6, IL-21 and IL-23 secretion, but promoted the secretion of IL-10 in the supernatants of PBMCs and SFMCs. In addition, LLDT-8 decreased the number of TRAP-positive cells derived from RAW264.7 in the presence of RANKL and M-CSF. Furthermore, LLDT-8 also inhibited the expression of p-IκB, a key regulator of RANKL signaling pathway.
  
  
  CONCLUSIONS
  LLDT-8 exerts its anti-osteoclastogenesis effect in RA probably through regulating RANKL/RANK/OPG system and its downstream signaling pathway as well as cytokine productions.
authors.affiliation: Department of Rheumatology, Shanghai Guanghua Hospital of Integrated Traditional and Western Medicine, Shanghai, 200052, China. shenyi_740@hotmail.com.|Arthritis Institute of integrated Traditional and Western medicine, Shanghai Chinese Medicine Research Institute, Shanghai, 200052, China. shenyi_740@hotmail.com.
authors.forename: Yi
authors.initials: Y
authors.lastname: Shen
authors.affiliation: Department of Rheumatology, Shanghai Guanghua Hospital of Integrated Traditional and Western Medicine, Shanghai, 200052, China. hbs1976@126.com.|Arthritis Institute of integrated Traditional and Western medicine, Shanghai Chinese Medicine Research Institute, Shanghai, 200052, China. hbs1976@126.com.
authors.forename: Ting
authors.initials: T
authors.lastname: Jiang
authors.affiliation: Department of Rheumatology, Shanghai Guanghua Hospital of Integrated Traditional and Western Medicine, Shanghai, 200052, China. rowson@sohu.com.|Arthritis Institute of integrated Traditional and Western medicine, Shanghai Chinese Medicine Research Institute, Shanghai, 200052, China. rowson@sohu.com.
authors.forename: Rongsheng
authors.initials: R
authors.lastname: Wang
authors.affiliation: Laboratory of Immunopharmacology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China. heshijun@mail.shcnc.ac.cn.
authors.forename: Shijun
authors.initials: S
authors.lastname: He
authors.affiliation: Department of Rheumatology, Shanghai Guanghua Hospital of Integrated Traditional and Western Medicine, Shanghai, 200052, China. mengruguo@sina.com.|Arthritis Institute of integrated Traditional and Western medicine, Shanghai Chinese Medicine Research Institute, Shanghai, 200052, China. mengruguo@sina.com.
authors.forename: Mengru
authors.initials: M
authors.lastname: Guo
authors.affiliation: Laboratory of Immunopharmacology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China. jpzuo@mail.shcnc.ac.cn.
authors.forename: Jianping
authors.initials: J
authors.lastname: Zuo
authors.affiliation: Department of Rheumatology, Shanghai Guanghua Hospital of Integrated Traditional and Western Medicine, Shanghai, 200052, China. hedongyish@163.com.|Arthritis Institute of integrated Traditional and Western medicine, Shanghai Chinese Medicine Research Institute, Shanghai, 200052, China. hedongyish@163.com.
authors.forename: Dongyi
authors.initials: D
authors.lastname: He
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D001172:Arthritis, Rheumatoid / Q000188:drug therapy / Q000378:metabolism*; D002454:Cell Differentiation / Q000187:drug effects; D004224:Diterpenes / Q000494:pharmacology* / Q000627:therapeutic use; D004365:Drugs, Chinese Herbal / Q000494:pharmacology* / Q000627:therapeutic use; D005260:Female; D006801:Humans; D016753:Interleukin-10 / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D007378:Interleukins / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000378:metabolism; D016173:Macrophage Colony-Stimulating Factor / Q000378:metabolism; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism; D051379:Mice; D008875:Middle Aged; D016328:NF-kappa B / Q000378:metabolism; D010010:Osteoclasts / Q000187:drug effects* / Q000502:physiology; D053244:Osteoprotegerin / Q000378:metabolism*; D008517:Phytotherapy; D053245:RANK Ligand / Q000378:metabolism*; D000067996:RAW 264.7 Cells; D053246:Receptor Activator of Nuclear Factor-kappa B / Q000378:metabolism*; D015398:Signal Transduction; D000098546:Interleukin-21
chemical_list: C509074:5-hydroxytriptolide; D004224:Diterpenes; D004365:Drugs, Chinese Herbal; C508609:IL10 protein, human; D015850:Interleukin-6; D007378:Interleukins; D008562:Membrane Glycoproteins; D016328:NF-kappa B; D053244:Osteoprotegerin; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; C506030:TNFRSF11B protein, human; C505688:TNFSF11 protein, human; D016753:Interleukin-10; D016173:Macrophage Colony-Stimulating Factor; D000098546:Interleukin-21