Different Inhibitors of Aβ42-Induced Toxicity Have Distinct Metal-Ion Dependency
| Autor: | Ashley J Mason, Ravinder Malik, Frank-Gerrit Klärner, Gal Bitan, Irit Sagi, Ian Hurst, Inna Solomonov, Thomas Schrader, Ibrar Siddique |
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| Rok vydání: | 2020 |
| Předmět: |
inorganic chemicals
Amyloid Physiology Cognitive Neuroscience Beta sheet Chemie Neurodegenerative Biochemistry Oligomer Article 03 medical and health sciences chemistry.chemical_compound Medicinal and Biomolecular Chemistry 0302 clinical medicine Alzheimer Disease neurotoxicity medicine Humans Viability assay 030304 developmental biology Ions 0303 health sciences Amyloid beta-Peptides Neurosciences Neurotoxicity aggregation metal ions Cell Biology General Medicine Alzheimer's disease medicine.disease In vitro Peptide Fragments inhibitor chemistry 5.1 Pharmaceuticals Toxicity Biophysics Development of treatments and therapeutic interventions Molecular tweezers Alzheimer’s disease 030217 neurology & neurosurgery |
| Zdroj: | ACS Chem Neurosci ACS chemical neuroscience, vol 11, iss 15 |
| ISSN: | 1948-7193 |
| Popis: | Oligomers of amyloid β-protein (Aβ) are thought to be the proximal toxic agents initiating the neuropathologic process in Alzheimer’s disease (AD). Therefore, targeting the self-assembly and oligomerization of Aβ has been an important strategy for designing AD therapeutics. In parallel, research into the metallobiology of AD has shown that Zn(2+) can strongly modulate the aggregation of Aβ in vitro and both promote and inhibit the neurotoxicity of Aβ, depending on the experimental conditions. Thus, successful inhibitors of Aβ self-assembly may have to inhibit the toxicity not only of Aβ oligomers themselves but also of Aβ-Zn(2+) complexes. However, there has been relatively little research investigating the effects of Aβ self-assembly and toxicity inhibitors in the presence of Zn(2+). Our group has characterized previously a series of Aβ42 C-terminal fragments (CTFs), some of which have been shown to inhibit Aβ oligomerization and neurotoxicity. Here, we asked whether three CTFs shown to be potent inhibitors of Aβ42 toxicity maintained their activity in the presence of Zn(2+). Biophysical analysis showed that the CTFs had different effects on oligomer, β-sheet, and fibril formation by Aβ42-Zn(2+) complexes. However, cell viability experiments in differentiated PC-12 cells incubated with Aβ42-Zn(2+) complexes in the absence or presence of these CTFs showed that the CTFs completely lost their inhibitory activity in the presence of Zn(2+) even when applied at 10-fold excess relative to Aβ42. In light of these results, we tested another inhibitor, the molecular tweezer CLR01, which coincidentally had been shown to have a high affinity for Zn(2+), suggesting that it could disrupt both Aβ42 oligomerization and Aβ42-Zn(2+) complexation. Indeed, we found that CLR01 effectively inhibited the toxicity of Aβ42-Zn(2+) complexes. Moreover, it did so at a lower concentration than needed for inhibiting the toxicity of Aβ42 alone. In agreement with these results, CLR01 inhibited β-sheet and fibril formation in Aβ42-Zn(2+) complexes. Our data suggest that, for the development of efficient therapeutic agents, inhibitors of Aβ self-assembly and toxicity should be examined in the presence of relevant metal ions and that molecular tweezers may be particularly attractive candidates for therapy development. |
| Databáze: | OpenAIRE |
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