Toluidine blue O attenuates tau phosphorylation in N2a-APPSwe cells


Onder S., BİBEROĞLU K., Yuksel M., TACAL Ö.

Chemico-Biological Interactions, cilt.366, 2022 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 366
  • Basım Tarihi: 2022
  • Doi Numarası: 10.1016/j.cbi.2022.110126
  • Dergi Adı: Chemico-Biological Interactions
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, BIOSIS, CAB Abstracts, Chemical Abstracts Core, EMBASE, MEDLINE, Veterinary Science Database
  • Anahtar Kelimeler: Alzheimer's disease, Amyloid-beta peptide, Tau phosphorylation, Tau kinases, Toluidine blue O
  • Hacettepe Üniversitesi Adresli: Evet

Özet

© 2022 Elsevier B.V.Alzheimer's disease (AD) is characterized by extracellular amyloid plaques composed of amyloid-β peptide (Aβ), intracellular neurofibrillary tangles containing hyperphosphorylated tau protein and neuronal loss. Most of the FDA-approved AD drugs currently on the market are cholinesterase inhibitors, which are only effective in relieving the symptoms of AD. However, recent studies in AD drug discovery focus on multi-targeted strategies, including anti-amyloid and anti-tau therapy. In the current study, we have investigated the effects of toluidine blue O (TBO), a cholinesterase inhibitor, on amyloid precursor protein (APP) processing, tau phosphorylation, and tau kinases/phosphatase in N2a mouse neuroblastoma cells stably expressing the Swedish mutation of human APP695 (N2a-APPSwe). The results demonstrated that TBO reduces Aβ40/42 levels by decreasing expression levels of β-secretase 1 (BACE1), presenilin 1 (PS1) and total APP without causing cytotoxic effects in N2a-APPSwe cells. TBO also decreased the levels of both total tau and phosphorylated tau at residues Ser202/Thr205, Thr181, Ser396 and Ser 396/Ser404. Moreover, when the possible mechanisms underlying its effects on tau pathology were explored, TBO was found to decrease tau phosphorylation at those sites by reducing the expression levels of Akt, GSK-3β, Cdk5, inactive p-PP2A and increasing the expression levels of p-Akt Ser473 and inactive p-GSK-3β Ser9. Our new data support the idea that TBO may be a promising multi-target drug candidate for the treatment of AD.