Huperzine A regulates amyloid precursor protein processing via protein kinase C and mitogen-activated protein kinase pathways in neuroblastoma SK-N-SH cells over-expressing wild type human amyloid precursor protein 695

Neuroscience. 2007 Dec 5;150(2):386-95. doi: 10.1016/j.neuroscience.2007.09.022. Epub 2007 Sep 14.


Alpha-secretase (alpha-secretase), cleaves the amyloid precursor protein (APP) within the amyloid-beta (Abeta) sequence, resulting in the release of a secreted fragment of APP (alphaAPPs) and precluding Abeta generation. We investigated the effects of the acetylcholinesterase inhibitor, huperzine A (Hup A), on APP processing and Abeta generation in human neuroblastoma SK-N-SH cells overexpressing wild-type human APP695. Hup A dose-dependently (0-10 microM) increased alphaAPPs release. Therefore, we evaluated two alpha-secretase candidates, a disintegrin and metalloprotease (ADAM) 10 and ADAM17 in Hup A-induced non-amyloidogenic APP metabolism. Hup A enhanced the level of ADAM10, and the inhibitor of tumor necrosis factor-alpha converting enzyme (TACE)/ADAM17 inhibited the Hup A-induced rise in alphaAPPs levels, further suggesting Hup A directed APP metabolism toward the non-amyloidogenic alpha-secretase pathway. Hup A had no effect on Abeta generation in this cell line. The steady-state levels of full-length APP and cell viability were unaffected by Hup A. Alpha-APPs release induced by Hup A treatment was significantly reduced by muscarinic acetylcholine receptor antagonists (particularly by an M1 antagonist), protein kinase C (PKC) inhibitors, GF109203X and calphostin C, and the mitogen-activated kinase kinase (MEK) inhibitors, U0126 and PD98059. Furthermore, Hup A markedly increased the phosphorylation of p44/p42 mitogen-activated protein (MAP) kinase, which was blocked by treatment with U0126 and PD98059. In addition, Hup A inhibited acetylcholinesterase activity by 20% in neuroblastoma cells. Our results indicate that the activation of muscarinic acetylcholine receptors, PKC and MAP kinase may be involved in Hup A-induced alphaAPPs secretion in neuroblastoma cells and suggest multiple pharmacological mechanisms of Hup A regarding the treatment of Alzheimer's disease (AD).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ADAM Proteins / drug effects
  • ADAM Proteins / metabolism
  • ADAM10 Protein
  • ADAM17 Protein
  • Alkaloids
  • Alzheimer Disease / drug therapy
  • Alzheimer Disease / metabolism
  • Alzheimer Disease / physiopathology
  • Amyloid Precursor Protein Secretases / drug effects
  • Amyloid Precursor Protein Secretases / metabolism
  • Amyloid beta-Peptides / biosynthesis*
  • Amyloid beta-Protein Precursor / drug effects*
  • Amyloid beta-Protein Precursor / metabolism
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Cell Survival / physiology
  • Cholinesterase Inhibitors / pharmacology
  • Dose-Response Relationship, Drug
  • Enzyme Activation / drug effects
  • Enzyme Activation / physiology
  • Enzyme Inhibitors / pharmacology
  • Humans
  • MAP Kinase Signaling System / drug effects*
  • MAP Kinase Signaling System / physiology
  • Membrane Proteins / drug effects
  • Membrane Proteins / metabolism
  • Mitogen-Activated Protein Kinase 3 / drug effects
  • Mitogen-Activated Protein Kinase 3 / metabolism
  • Muscarinic Antagonists / pharmacology
  • Neuroblastoma
  • Neurons / drug effects*
  • Neurons / metabolism
  • Peptide Fragments / drug effects
  • Peptide Fragments / metabolism
  • Phosphorylation / drug effects
  • Protein Kinase C / drug effects
  • Protein Kinase C / metabolism
  • Receptors, Muscarinic / drug effects
  • Receptors, Muscarinic / metabolism
  • Sesquiterpenes / pharmacology*


  • Alkaloids
  • Amyloid beta-Peptides
  • Amyloid beta-Protein Precursor
  • Cholinesterase Inhibitors
  • Enzyme Inhibitors
  • Membrane Proteins
  • Muscarinic Antagonists
  • Peptide Fragments
  • Receptors, Muscarinic
  • Sesquiterpenes
  • amyloid beta-protein precursor 695 (18-38)
  • huperzine A
  • Protein Kinase C
  • Mitogen-Activated Protein Kinase 3
  • Amyloid Precursor Protein Secretases
  • ADAM Proteins
  • ADAM10 Protein
  • ADAM10 protein, human
  • ADAM17 Protein
  • ADAM17 protein, human