title: Celastrol inhibits lipopolysaccharide-induced angiogenesis by suppressing TLR4-triggered nuclear factor-kappa B activation.
abstract: Celastrol is an active compound extracted from the root bark of the traditional Chinese medicine Tripterygium wilfordii Hook F. In this study, we investigated the effect of celastrol on lipopolysaccharide (LPS)-activated LP-1 human multiple myeloma cell-induced angiogenesis, and identified its molecular mechanism of action. Migration of human umbilical vein endothelial cells (HUVECs) was tested using a wound-healing assay. HUVEC invasion was assayed using a Transwell chamber. Cell surface expression of Toll-like receptor 4 (TLR4) was analyzed by flow cytometry. Angiogenic factor vascular endothelial growth factor (VEGF) level was quantified by LUMINEX and protein expression was analyzed by Western blot. Translocation of nuclear factor-kappa B (NF-κB) was observed by fluorescence microscopy. Celastrol inhibited LPS-stimulated LP-1 human multiple myeloma-induced HUVEC migration and invasion in a concentration-dependent manner. Wound diameters increased by 72.9, 165.4 and 246.2% at 0.025, 0.05 and 0.1 μM, respectively, compared to LPS alone. A 45-74% inhibition of LPS-dependent cell invasion was achieved in the presence of 0.025-0.1 μM celastrol. Celastrol significantly downregulated LPS-induced TLR4 expression and inhibited LPS-induced VEGF secretion in LP-1 cells. VEGF levels decreased by 64.8, 84.4 and 92.9% after coexposure to celastrol at 0.025, 0.05 and 0.1 μM, respectively, compared to LPS alone. Celastrol also inhibited the IκB kinase (IKK)/NF-κB pathway induced by LPS. Protein levels of NF-κB p65, IKKα and IκB-α decreased in a dose-dependent manner after coexposure to celastrol. Celastrol also blocked nuclear translocation of the p65 subunit. These results suggest that celastrol inhibits LPS-induced angiogenesis by suppressing TLR4-triggered NF-κB activation.
authors.affiliation: Affiliated Hospital of Nanjing University of TCM, Nanjing, China.
authors.forename: Haiwen
authors.initials: H
authors.lastname: Ni
authors.forename: Wanzhou
authors.initials: W
authors.lastname: Zhao
authors.forename: Xiangtu
authors.initials: X
authors.lastname: Kong
authors.forename: Haitao
authors.initials: H
authors.lastname: Li
authors.forename: Jian
authors.initials: J
authors.lastname: Ouyang
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D020533:Angiogenesis Inhibitors / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D017077:Culture Media, Conditioned / Q000494:pharmacology; D015536:Down-Regulation; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D051550:I-kappa B Kinase / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics; D020672:I-kappa B Proteins / Q000235:genetics / Q000378:metabolism; D008070:Lipopolysaccharides / Q000633:toxicity; D015394:Molecular Structure; D009101:Multiple Myeloma / Q000378:metabolism / Q000473:pathology; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000378:metabolism*; D009389:Neovascularization, Pathologic / Q000188:drug therapy*; D053978:Pentacyclic Triterpenes; D051197:Toll-Like Receptor 4 / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D051996:Transcription Factor RelA / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects; D014315:Triterpenes / Q000737:chemistry / Q000494:pharmacology*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D014945:Wound Healing
chemical_list: D020533:Angiogenesis Inhibitors; D017077:Culture Media, Conditioned; D020672:I-kappa B Proteins; D008070:Lipopolysaccharides; D016328:NF-kappa B; C000606204:NFKBIA protein, human; D053978:Pentacyclic Triterpenes; C498143:RELA protein, human; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; D051996:Transcription Factor RelA; D014315:Triterpenes; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D000072000:NF-KappaB Inhibitor alpha; D051550:I-kappa B Kinase; C050414:celastrol