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Pharmacological targets to inhibit alzheimer neurofibrillary degeneration

  • K. Iqbal
  • A.C. del Alonso
  • E. El-Akkad
  • C.-X. Gong
  • N. Haque
  • S. Khatoon
  • I. Tsujio
  • I. Grundke-Iqbal
Part of the Journal of Neural Transmission. Supplementa book series (NEURAL SUPPL, volume 62)

Abstract

Neurofibrillary degeneration appears to be required for the clinical expression of Alzheimer disease (AD) and related tauopathies. Given the polyetiology of these diseases and the pivotal involvement of neurofibrillary degeneration in their pathogenesis, inhibition of this lesion offers a promising therapeutic target. Studies from our laboratories have shown that there is a protein phosphorylation/dephosphorylation imbalance and that the microtubule associated protein tau is abnormally hyperphosphorylated in the brain of patients with AD and in this form it is the major protein subunit of paired helical filaments/neurofibrillary tangles (PHF/NFT). The abnormal tau which is polymerized into PHF/NFT neither promotes or inhibits in vitro microtubule assembly. In contrast the cytosolic abnormally hyperphosphorylated tau from AD brain, the AD P-tau neither associates with tubulin nor promotes in vitro microtubule assembly but instead it sequesters normal tau, MAPI and MAP2 and inhibits microtubule assembly. The AD P-tau readily self-assembles in vitro into tangles of PHF/straight filaments under physiological conditions of protein concentration, pH, ionic strength and reducing conditions and this self assembly requires the abnormal hyperphosphorylation of this protein. The activity of phosphoseryl/phosphothreonyl protein phosphatase (PP)-2A which regulates the phosphorylation of tau, is compromised in AD brain. Thus, modulation of the activities of protein phosphatase-2A and tau kinases and inhibition of the sequestration of normal MAPs by AD P-tau offer promising therapeutic opportunities to inhibit neurofibrillary degeneration and the diseases characterized by this lesion.

Keywords

Alzheimer Disease Microtubule Assembly Paired Helical Filament Alzheimer Disease Brain Neurofibrillary Degeneration 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag Wien 2002

Authors and Affiliations

  • K. Iqbal
    • 1
  • A.C. del Alonso
    • 1
  • E. El-Akkad
    • 1
  • C.-X. Gong
    • 1
  • N. Haque
    • 1
  • S. Khatoon
    • 1
  • I. Tsujio
    • 1
  • I. Grundke-Iqbal
    • 1
  1. 1.New York State Institute for Basic Research in Developmental DisabilitiesStaten IslandNYUSA

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