Preparation and characterization of toxic Aβ aggregates for structural and functional studies in Alzheimer's disease research

Jan, Asad; Hartley, Dean M.; Lashuel, Hilal A.

doi:10.1038/nprot.2010.72

Cited by 220 publications

(243 citation statements)

References 94 publications

(168 reference statements)

Supporting

Mentioning

227

Contrasting

Order By: Relevance

“…To determine whether the cytotoxicity of protofibrils is associated with specific type of aggregates or depends on the dynamics of inter-conversion among different aggregate species, we subjected a crude A␤42 protofibril preparation (A␤42 CR) to fractionation by SEC (12,24). Then we investigated the cellular toxicity of individual A␤42 fractions, enriched with distinct protofibrillar aggregates, using cultured PC12 and SHSY5Y cells.…”

Section: Sec Subfractionation Retards Elongation Of Protofibrils Andmentioning

confidence: 99%

“…Decreases Toxicity-We and others have shown that toxic A␤ protofibril preparations consist of a heterogeneous mixture of high molecular weight aggregates of various sizes and morphologies (12,24,30). To determine whether the cytotoxicity of protofibrils is associated with specific type of aggregates or depends on the dynamics of inter-conversion among different aggregate species, we subjected a crude A␤42 protofibril preparation (A␤42 CR) to fractionation by SEC (12,24).…”

Section: Sec Subfractionation Retards Elongation Of Protofibrils Andmentioning

confidence: 99%

“…Crude A␤42 protofibril (A␤42 CR) solution was prepared as described previously (24,27). Briefly, 1 mg of lyophilized A␤42 was solubilized in 50 l of 100% anhydrous DMSO in a 1.5-ml sterile microtube.…”

Section: Preparation Of A␤42 Protofibrilsmentioning

confidence: 99%

“…SEC columns were thoroughly equilibrated with SEC running buffer (10 mM Tris-HCl, pH 7.4) prior to A␤ injections. A␤ (40 and 42) monomers and A␤42 protofibrils were obtained by SEC as described previously (24,27). To prepare A␤ monomers, 1 mg of lyophilized A␤ was dissolved in 1 ml of 6 M guanidine HCl solution and subsequently centrifuged (16,000 ϫ g, 4°C, 10 min).…”

Section: Size Exclusion Chromatographymentioning

confidence: 99%

“…To test this hypothesis, we developed different procedures to isolate A␤ species of defined size and morphology distribution (24), and we investigated their toxicity in different cell lines and primary neurons. We observed that crude A␤42 preparations, containing a monomeric and heterogeneous mixture of A␤42 oligomers and protofibrils, were more toxic than the purified monomeric protofibrillar fractions or fibrils.…”

mentioning

confidence: 99%

See 4 more Smart Citations

Aβ42 Neurotoxicity Is Mediated by Ongoing Nucleated Polymerization Process Rather than by Discrete Aβ42 Species

Jan¹,

Adolfsson

Allaman

et al. 2011

Journal of Biological Chemistry

Self Cite

166

158

View full text Add to dashboard Cite

Aggregation of amyloid-␤ (A␤)2 peptides and deposition into neuritic plaques are hallmark features of Alzheimer disease (AD) neuropathology (1, 2). Therefore, research efforts during the past 3 decades have focused on elucidating the mechanisms of A␤ fibrillization, identifying toxic species, and developing strategies to inhibit and/or reverse A␤ amyloid formation and toxicity in vivo (3,4).A␤ peptides are produced as soluble monomers (5, 6) and undergo oligomerization and amyloid fibril formation via a nucleation-dependent polymerization process (7,8). During the course of in vitro A␤ fibril formation, various nonfibrillar aggregation intermediates, collectively called soluble oligomers or protofibrils, have been shown to precede the emergence of fibrils. Increasing evidence from various sources points to A␤ oligomers/protofibrils as putative toxic species in AD pathogenesis and suggests that these species are potential therapeutic targets for treating AD (reviewed in Refs. 9, 10). Although the toxic oligomer hypothesis has emerged as one of the major current working hypotheses in AD research, the development of effective diagnostic tools and therapies on the basis of this hypothesis has yet to be realized (11-13). This is partially due to the fact that identification of a single toxic A␤ species that correlates with AD progression and severity remains elusive. Furthermore, the exact mechanisms by which these species contribute to A␤ toxicity in vivo and the nature of the toxic species are not yet fully understood. Recent evidence suggests that accelerating the process of A␤ fibrillization greatly enhances A␤ toxicity in vitro (14) and the spread of amyloid pathology in vivo (15-17).Despite significant efforts by different groups to isolate specific intermediates along the amyloid formation pathway (12, 18 -22), the inherent heterogeneity of the process and metastable nature of A␤ oligomers (11-13) have precluded the isolation of a single toxic species. Unless covalently crosslinked (23), A␤ oligomers do not exist as stable entities, i.e. they evolve into higher order aggregates and, if they are onpathway intermediates, convert into fibrils (19). Therefore, it is plausible to assume that the structural dynamics of oligomers and factors that govern their interconversion and/or growth might influence some of the disease-related cytotoxic effects of A␤. In other words, an ongoing polymerization

show abstract

Section: Sec Subfractionation Retards Elongation Of Protofibrils Andmentioning

confidence: 99%

Section: Sec Subfractionation Retards Elongation Of Protofibrils Andmentioning

confidence: 99%

Section: Preparation Of A␤42 Protofibrilsmentioning

confidence: 99%

Section: Size Exclusion Chromatographymentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Aβ42 Neurotoxicity Is Mediated by Ongoing Nucleated Polymerization Process Rather than by Discrete Aβ42 Species

Jan¹,

Adolfsson

Allaman

et al. 2011

Journal of Biological Chemistry

Self Cite

166

158

View full text Add to dashboard Cite

show abstract

Protofibril–Fibril Interactions Inhibit Amyloid Fibril Assembly by Obstructing Secondary Nucleation

et al. 2020

View full text Add to dashboard Cite

Amyloid‐β peptides (Aβ) assemble into both rigid amyloid fibrils and metastable oligomers termed AβO or protofibrils. In Alzheimer's disease, Aβ fibrils constitute the core of senile plaques, but Aβ protofibrils may represent the main toxic species. Aβ protofibrils accumulate at the exterior of senile plaques, yet the protofibril–fibril interplay is not well understood. Applying chemical kinetics and atomic force microscopy to the assembly of Aβ and lysozyme, protofibrils are observed to bind to the lateral surfaces of amyloid fibrils. When utilizing Aβ variants with different critical oligomer concentrations, the interaction inhibits the autocatalytic proliferation of amyloid fibrils by secondary nucleation on the fibril surface. Thus, metastable oligomers antagonize their replacement by amyloid fibrils both by competing for monomers and blocking secondary nucleation sites. The protofibril—fibril interaction governs their temporal evolution and potential to exert specific toxic activities.

show abstract

Protofibril–Fibril Interactions Inhibit Amyloid Fibril Assembly by Obstructing Secondary Nucleation

et al. 2020

View full text Add to dashboard Cite

Amyloid-b peptides (Ab) assemble into both rigid amyloid fibrils and metastable oligomers termed AbO or protofibrils. In Alzheimers disease, Ab fibrils constitute the core of senile plaques, but Ab protofibrils may represent the main toxic species. Ab protofibrils accumulate at the exterior of senile plaques, yet the protofibril-fibril interplay is not well understood. Applying chemical kinetics and atomic force microscopy to the assembly of Ab and lysozyme, protofibrils are observed to bind to the lateral surfaces of amyloid fibrils. When utilizing Ab variants with different critical oligomer concentrations, the interaction inhibits the autocatalytic proliferation of amyloid fibrils by secondary nucleation on the fibril surface. Thus, metastable oligomers antagonize their replacement by amyloid fibrils both by competing for monomers and blocking secondary nucleation sites. The protofibril-fibril interaction governs their temporal evolution and potential to exert specific toxic activities.

show abstract

Preparation and characterization of toxic Aβ aggregates for structural and functional studies in Alzheimer's disease research

Cited by 220 publications

References 94 publications

Aβ42 Neurotoxicity Is Mediated by Ongoing Nucleated Polymerization Process Rather than by Discrete Aβ42 Species

Aβ42 Neurotoxicity Is Mediated by Ongoing Nucleated Polymerization Process Rather than by Discrete Aβ42 Species

Protofibril–Fibril Interactions Inhibit Amyloid Fibril Assembly by Obstructing Secondary Nucleation

Protofibril–Fibril Interactions Inhibit Amyloid Fibril Assembly by Obstructing Secondary Nucleation

Contact Info

Product

Resources

About