271 Pharmacological manipulation of Alzheimer's amyloid β protein in vitro and in vivo

Abstract Background Molecular tweezers (MTs) are broad-spectrum inhibitors of abnormal protein aggregation. A lead MT, called CLR01, has been demonstrated to inhibit the aggregation and toxicity of multiple amyloidogenic proteins in vitro and in vivo. Previously, we evaluated the effect of CLR01 in the 3 × Tg mouse model of Alzheimer’s disease, which overexpresses mutant human presenilin 1, amyloid β-protein precursor, and tau and found that subcutaneous administration of the compound for 1 month led to a robust reduction of amyloid plaques, neurofibrillary tangles, and microgliosis. CLR01 also has been demonstrated to inhibit tau aggregation in vitro and tau seeding in cell culture, yet because in Alzheimer’s disease (AD) and in the 3 × Tg model, tau hyperphosphorylation and aggregation are thought to be downstream of Aβ insults, the study in this model left open the question whether CLR01 affected tau in vivo directly or indirectly. Methods To determine if CLR01 could ameliorate tau pathology directly in vivo, we tested the compound similarly using the P301S-tau (line PS19) mouse model. Mice were administered 0.3 or 1.0 mg/kg per day CLR01 and tested for muscle strength and behavioral deficits, including anxiety- and disinhibition-like behavior. Their brains then were analyzed by immunohistochemical and biochemical assays for pathological forms of tau, neurodegeneration, and glial pathology. Results CLR01 treatment ameliorated muscle-strength deterioration, anxiety-, and disinhibition-like behavior. Improved phenotype was associated with decreased levels of pathologic tau forms, suggesting that CLR01 exerts a direct effect on tau in vivo. Limitations of the study included a relatively short treatment period of the mice at an age in which full pathology is not yet developed. In addition, high variability in this model lowered the statistical significance of the findings of some outcome measures. Conclusions The findings suggest that CLR01 is a particularly attractive candidate for the treatment of AD because it targets simultaneously the two major pathogenic proteins instigating and propagating the disease, amyloid β-protein (Aβ), and tau, respectively. In addition, our study suggests that CLR01 can be used for the treatment of other tauopathies in the absence of amyloid pathology.

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RRY Inhibits Amyloid-β1–42 Peptide Aggregation and Neurotoxicity

Journal of Alzheimer s Disease Reports ◽

10.3233/adr-210012 ◽

2021 ◽

pp. 1-17

Author(s):

Xicui Sun ◽

Songwei Duan ◽

Anna Cao ◽

Bryan Villagomez ◽

Runxuan Lin ◽

...

Keyword(s):

In Silico ◽

Cognitive Deficit ◽

Amyloid Β ◽

In Vivo Studies ◽

Amyloid Β Protein ◽

Transmission Electron ◽

Β Protein ◽

Aβ Aggregation

Background: Current understanding of amyloid-β protein (Aβ) aggregation and toxicity provides an extensive list of drugs for treating Alzheimer’s disease (AD); however, one of the most promising strategies for its treatment has been tri-peptides. Objective: The aim of this study is to examine those tri-peptides, such as Arg-Arg-Try (RRY), which have the potential of Aβ1–42 aggregating inhibition and Aβ clearance. Methods: In the present study, in silico, in vitro, and in vivo studies were integrated for screening tri-peptides binding to Aβ, then evaluating its inhibition of aggregation of Aβ, and finally its rescuing cognitive deficit. Results: In the in silico simulations, molecular docking and molecular dynamics determined that seven top-ranking tri-peptides could bind to Aβ 1–42 and form stable complexes. Circular dichroism, ThT assay, and transmission electron microscope indicated the seven tri-peptides might inhibit the aggregation of Aβ 1–42 in vitro. In the in vivo studies, Morris water maze, ELISA, and Diolistic staining were used, and data showed that RRY was capable of rescuing the Aβ1–42-induced cognitive deficit, reducing the Aβ1–42 load and increasing the dendritic spines in the transgenic mouse model. Conclusion: Such converging outcomes from three consecutive studies lead us to conclude that RRY is a preferred inhibitor of Aβ 1–42 aggregation and treatment for Aβ-induced cognitive deficit.

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The molecular tweezer CLR01 improves behavioral deficits and reduces tau pathology in P301S-tau transgenic mice

10.21203/rs.3.rs-88943/v1 ◽

2020 ◽

Author(s):

Jing Di ◽

Ibrar Siddique ◽

Zizheng Li ◽

Ghattas Malki ◽

Simon Hornung ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Muscle Strength ◽

Mouse Model ◽

Amyloid Β ◽

Amyloid Β Protein ◽

Tau Pathology ◽

Behavioral Deficits ◽

Β Protein

Abstract Background: Molecular tweezers (MTs) are broad-spectrum inhibitors of abnormal protein aggregation. A lead MT, called CLR01, has been demonstrated to inhibit the aggregation and toxicity of multiple amyloidogenic proteins in vitro and in vivo. Previously, we evaluated the effect of CLR01 in the 3×Tg mouse model of Alzheimer’s disease, which overexpresses mutant human presenilin 1, amyloid β-protein precursor, and tau and found that subcutaneous administration of the compound for one month led to a robust reduction of amyloid plaques, neurofibrillary tangles, and microgliosis. CLR01 also has been demonstrated to inhibit tau aggregation in vitro and tau seeding in cell culture, yet because in Alzheimer’s disease (AD) and in the 3×Tg model, tau hyperphosphorylation and aggregation are thought to be downstream of Aβ insults, the study in this model left the question whether CLR01 affected tau in vivo directly or indirectly open.Methods: To determine if CLR01 could ameliorate tau pathology directly in vivo, we tested the compound similarly using the P301S-tau (line PS19) mouse model. Mice were administered 0.3- or 1.0-mg/Kg per day CLR01 and tested for muscle strength and behavioral deficits, including anxiety- and disinhibition-like behavior. Their brains then were analyzed by immunohistochemical and biochemical assays for pathological forms of tau, neurodegeneration, and glial pathology.Results: CLR01 treatment ameliorated muscle-strength deterioration, anxiety-, and disinhibition-like behavior. Improved phenotype was associated with decreased levels of pathologic tau forms, suggesting that CLR01 exerts a direct effect on tau in vivo. Limitations of the study included a relatively short treatment period of the mice at an age in which full pathology is not yet developed. In addition, high variability in this model lowered the statistical significance of the findings of some outcome measures.Conclusions: The findings suggest that CLR01 is a particularly attractive candidate for the treatment of AD because it targets simultaneously the two major pathogenic proteins instigating and propagating the disease, amyloid β-protein (Aβ) and tau, respectively. In addition, our study suggests that CLR01 can be used for the treatment of other tauopathies in the absence of amyloid pathology.

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