Inhibition of tau fibrillization by oleocanthal via reaction with the amino groups of tau.
Tau is a microtubule-associated protein that promotes microtubule assembly and stability. In Alzheimer's disease and related tauopathies, tau fibrillizes and aggregates into neurofibrillary tangles. Recently, oleocanthal isolated from extra virgin olive oil was found to display non-steroidal anti-inflammatory activity similar to ibuprofen. As our unpublished data indicates an inhibitory effect of oleocanthal on amyloid beta peptide fibrillization, we reasoned that it might inhibit tau fibrillization as well. Herein, we demonstrate that oleocanthal abrogates fibrillization of tau by locking tau into the naturally unfolded state. Using PHF6 consisting of the amino acid residues VQIVYK, a hexapeptide within the third repeat of tau that is essential for fibrillization, we show that oleocanthal forms an adduct with the lysine via initial Schiff base formation. Structure and function studies demonstrate that the two aldehyde groups of oleocanthal are required for the inhibitory activity. These two aldehyde groups show certain specificity when titrated with free lysine and oleocanthal does not significantly affect the normal function of tau. These findings provide a potential scheme for the development of novel therapies for neurodegenerative tauopathies.
Li
Wenkai
W
Department of Pathology and Laboratory Medicine, Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 94305, USA.
Sperry
Jeffrey B
JB
Crowe
Alex
A
Trojanowski
John Q
JQ
Smith
Amos B
AB
Lee
Virginia M-Y
VM
D000447:Aldehydes / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology* / Q000627:therapeutic use; D000595:Amino Acid Sequence / Q000187:drug effects / Q000502:physiology; D000596:Amino Acids / Q000187:drug effects / Q000378:metabolism; D000893:Anti-Inflammatory Agents / Q000494:pharmacology / Q000627:therapeutic use; D001921:Brain / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D000081004:Cyclopentane Monoterpenes; D004660:Encephalitis / Q000188:drug therapy / Q000378:metabolism / Q000503:physiopathology; D006801:Humans; D008239:Lysine / Q000378:metabolism; D015394:Molecular Structure; D016874:Neurofibrillary Tangles / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D009454:Neurofibrils / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D018696:Neuroprotective Agents / Q000494:pharmacology / Q000627:therapeutic use; D010455:Peptides / Q000737:chemistry / Q000378:metabolism; D010636:Phenols / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use; D017510:Protein Folding / Q000187:drug effects; D012545:Schiff Bases / Q000737:chemistry / Q000378:metabolism; D024801:Tauopathies / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D016875:tau Proteins / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism
D000447:Aldehydes; D000596:Amino Acids; D000893:Anti-Inflammatory Agents; D000081004:Cyclopentane Monoterpenes; D018696:Neuroprotective Agents; D010455:Peptides; D010636:Phenols; D012545:Schiff Bases; D016875:tau Proteins; C503534:oleocanthal; D008239:Lysine