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

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.

Anti-Biofilm Molecules Targeting Functional Amyloids

“…Therefore, these macromolecules may work as singular molecular receptors for specific targets that can be used in numerous applications in biology and medicine [114]. Among the different applications, it was reported that a lysine-binding tweezer (CLR01) inhibits the self-assembly of different human amyloidogenic proteins, including Aβ protein, tau, and α-synuclein in vitro and in vivo [115,116]. CLR01 alters the assembly process and promotes the formation of non-amyloidogenic structures that can be efficiently removed by host clearance mechanisms (Figure 2a).…”

Lysine-selective molecular tweezers are cell-penetrant and concentrate in lysosomes

“…Tau-seeds were prepared from PS19-mouse hippocampal extracts and added to biosensor cells for measurement of intracellular tau aggregation as described previously 48 . CLR16 was added 24 h after seeding.…”

Biomimetic Recognition-Based Bioorthogonal Host–Guest Pairs for Cell Targeting and Tissue Imaging in Living Animals

“…Many host-guest pairs have been used in 3 guest-conjugated targets in complex biological media. 17,18,19,20,21,22,2324,25,26,27,28,29,30 It is even more challenging to achieve in situ capture in living animals, and there are only very limited successful examples via employing either monovalent 31,32 or multivalent 33,34 systems. In situ capture requires the host-guest pairs to be bioorthogonal, that is, the host-guest pairs are not interfered by biomolecules and salt ions.…”