title: Celastrol enhances cell viability and inhibits amyloid-β production induced by lipopolysaccharide in vitro.
abstract: BACKGROUND
  Neuroinflammation is a notable hallmark of Alzheimer's disease pathogenesis and can markedly exacerbate amyloid pathology. Celastrol, a pentacyclic-triterpene, has been found to possess anti-inflammatory properties.
  
  
  OBJECTIVE
  The purpose of this study was to characterize the effects of celastrol on cell viability and amyloid-β (Aβ) peptide production induced by lipopolysaccharide (LPS) administration in H4 human neuroglioma cells stably transfected to overexpress human full length APP (H4-APP).
  
  
  METHODS
  H4-APP cells were exposed to 1, 10, and 100 nM of celastrol in the presence of 0.1 μg/ml or 100 μg/ml of LPS for 24 hours. The effects of celastrol were determined using MTT cell viability assay, immunohistochemistry, western blot, and ELISA.
  
  
  RESULTS
  Cell viability tests revealed that a dose-dependent death of H4-APP cells following administration of LPS. Moreover, celastrol significantly reduced (p < 0.05) cell death induced by LPS compared to LPS alone. Furthermore, the administration of celastrol was associated with a significant reduction in LPS-stimulated Aβ production compared to LPS alone. Western blot and immunofluorescence analysis showed that exposure to celastrol increased HSP-70 and Bcl-2 expression but decreased NFκB activity, phosphorylated glycogen synthase kinase-3β (GSK-3β) at tyrosine 216 and cyclooxygenase-2 (COX-2) expression, Aβ accumulation together with a reduction of superoxide and hydrogen peroxide generation. HSP-70 siRNA abolished celastrol mediated cytoprotection.
  
  
  CONCLUSIONS
  This study demonstrates that celastrol reduced both LPS-induced cell death and Aβ production in vitro through increasing HSP-70 and Bcl-2 expression and reducing NFκB, COX-2, and GSK-3β expression and oxidative stress.
authors.affiliation: Department of Anesthesiology, Peking University Third Hospital, Beijing, China Anaesthetics, Pain Medicine and Intensive Care, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Chelsea & Westminster Hospital, London, UK.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Anaesthetics, Pain Medicine and Intensive Care, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Chelsea & Westminster Hospital, London, UK.
authors.forename: Hailin
authors.initials: H
authors.lastname: Zhao
authors.affiliation: Anaesthetics, Pain Medicine and Intensive Care, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Chelsea & Westminster Hospital, London, UK.
authors.forename: Niyati
authors.initials: N
authors.lastname: Lobo
authors.affiliation: Department of Anesthesiology, Peking University Third Hospital, Beijing, China.
authors.forename: Xiangyang
authors.initials: X
authors.lastname: Guo
authors.affiliation: Neuropathology unit, Department of Medicine, Imperial College London, Charing Cross Campus, London, UK.
authors.forename: Steve M
authors.initials: SM
authors.lastname: Gentleman
authors.affiliation: Anaesthetics, Pain Medicine and Intensive Care, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Chelsea & Westminster Hospital, London, UK.
authors.forename: Daqing
authors.initials: D
authors.lastname: Ma
mesh_terms: D016229:Amyloid beta-Peptides / Q000378:metabolism*; D016564:Amyloid beta-Protein Precursor / Q000235:genetics; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D051546:Cyclooxygenase 2 / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects; D038341:Glycogen Synthase Kinases / Q000378:metabolism; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology*; D016328:NF-kappa B / Q000378:metabolism; D009447:Neuroblastoma / Q000473:pathology; D053978:Pentacyclic Triterpenes; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D034741:RNA, Small Interfering / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism; D013997:Time Factors; D014162:Transfection; D014315:Triterpenes / Q000494:pharmacology*
chemical_list: D016229:Amyloid beta-Peptides; D016564:Amyloid beta-Protein Precursor; D004791:Enzyme Inhibitors; D018840:HSP70 Heat-Shock Proteins; D008070:Lipopolysaccharides; D016328:NF-kappa B; D053978:Pentacyclic Triterpenes; D019253:Proto-Oncogene Proteins c-bcl-2; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; D014315:Triterpenes; D006861:Hydrogen Peroxide; D051546:Cyclooxygenase 2; D038341:Glycogen Synthase Kinases; C050414:celastrol
keywords: Alzheimer's disease; amyloid-β; celastrol; cell signal; lipopolysaccharide; neuroinflammation