title: Stimulation of non-amyloidogenic processing of amyloid-β protein precursor by cryptotanshinone involves activation and translocation of ADAM10 and PKC-α.
abstract: Cerebral deposition of amyloid-β peptide (Aβ) plaques is now considered the central feature of Alzheimer's disease. Recent studies suggest that cryptotanshinone (CTS) extracted from the root of Salvia miltiorrhiza Bunge could be used for the prevention and treatment of Alzheimer's disease. In this study, we investigated the role of CTS on non-amyloidogenic processing of amyloid-β protein precursor (AβPP) as well as its regulation by protein kinase C (PKC). Treatment with CTS dose-dependently and significantly reduced both intracellular and secreted levels of Aβ40 and Aβ42 in N2a mouse neuroblastoma cells stably expressing human SwedishAβPP (N2a-SwedAβPP). Using N2a-SwedAβPP and human neuroblastoma SHSY5Y cells, it was demonstrated that CTS significantly and dose-dependently increased the production of sAβPPα and C-terminal fragment-α (CTF-α) from AβPP. At the same time, CTS specifically increased the maturation of "a disintegrin and metalloproteinase-10" (ADAM10), an α-secretase candidate. The increase of sAβPPα secretion by CTS was blocked by the hydroxamate-based inhibitors GI254023X and GW280264X, and by the PKC-α inhibitor GÖ6976, suggesting involvement of the ADAM10 and PKC-α in CTS-induced α-secretase cleavage. In other experiments, CTS induced the phosphorylation of PKC-α indicating that PKC-α is involved in CTS-induced sAβPPα secretion. Furthermore, treatment of neuroblastoma cells with CTS induced the co-translocation of ADAM10 and PKC-α to the cell membrane, the site at which AβPP was cleaved, and this translocation was significantly reduced by GÖ6976. These results suggest that CTS-induced sAβPPα secretion is regulated by a PKC-α and ADAM10 cascade in neuroblastoma cells and may be involved in the lowering of Aβ production.
authors.affiliation: School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong.
authors.forename: Siva Sundara Kumar
authors.initials: SS
authors.lastname: Durairajan
authors.forename: Liang-Feng
authors.initials: LF
authors.lastname: Liu
authors.forename: Jia-Hong
authors.initials: JH
authors.lastname: Lu
authors.forename: Irene
authors.initials: I
authors.lastname: Koo
authors.forename: Kei
authors.initials: K
authors.lastname: Maruyama
authors.forename: Sookja K
authors.initials: SK
authors.lastname: Chung
authors.forename: Jian-Dong
authors.initials: JD
authors.lastname: Huang
authors.forename: Min
authors.initials: M
authors.lastname: Li
mesh_terms: D051722:ADAM Proteins / Q000378:metabolism*; D000072197:ADAM10 Protein; D053829:Amyloid Precursor Protein Secretases / Q000378:metabolism*; D016229:Amyloid beta-Peptides / Q000378:metabolism; D016564:Amyloid beta-Protein Precursor / Q000235:genetics / Q000378:metabolism*; D000704:Analysis of Variance; D000818:Animals; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D009447:Neuroblastoma / Q000473:pathology; D010616:Phenanthrenes / Q000494:pharmacology*; D051571:Protein Kinase C-alpha / Q000378:metabolism*; D021381:Protein Transport / Q000187:drug effects; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D013997:Time Factors; D014162:Transfection / Q000379:methods
chemical_list: D016229:Amyloid beta-Peptides; D016564:Amyloid beta-Protein Precursor; D004791:Enzyme Inhibitors; D008565:Membrane Proteins; D010616:Phenanthrenes; D034741:RNA, Small Interfering; C037886:cryptotanshinone; D051571:Protein Kinase C-alpha; D053829:Amyloid Precursor Protein Secretases; D051722:ADAM Proteins; D000072197:ADAM10 Protein; C491236:ADAM10 protein, human