Targeting soluble amyloid-beta oligomers with a novel nanobody.

The classical amyloid cascade hypothesis postulates that the aggregation of amyloid plaques and the accumulation of intracellular hyperphosphorylated Tau tangles, together, lead to profound neuronal death. However, emerging research has demonstrated that soluble amyloid-β oligomers (SAβOs) accumulate early, prior to amyloid plaque formation. SAβOs induce memory impairment and disrupt cognitive function independent of amyloid-β plaques, and even in the absence of plaque formation.

Synthesis and Evaluation of a Novel PET Radioligand for Imaging Glutaminyl Cyclase Activity as a Biomarker for Detecting Alzheimer's Disease.

Several new lines of research have demonstrated that a significant number of amyloid-β peptides found in Alzheimer's disease (AD) are truncated and undergo post-translational modification by glutaminyl cyclase (QC) at the N-terminal. Notably, QC's products of Abeta-pE3 and Abeta-pE11 have been active targets for investigational drug development. This work describes the design, synthesis, characterization, and in vivo validation of a novel PET radioligand, [F]PB0822, for targeted imaging of QC.

TARGETING SOLUBLE AMYLOID-BETA OLIGOMERS WITH A NOVEL NANOBODY.

The classical amyloid cascade hypothesis postulates that the aggregation of amyloid plaques and the accumulation of intracellular hyperphosphorylated Tau tangles, together, lead to profound neuronal death. However, emerging research has demonstrated that soluble amyloid-β oligomers (SAβOs) accumulate early, prior to amyloid plaque formation. SAβOs induce memory impairment and disrupt cognitive function independent of amyloid-β plaques, and even in the absence of plaque formation.

Ergothioneine, a dietary antioxidant improves amyloid beta clearance in the neuroretina of a mouse model of Alzheimer's disease.

Introduction: Ergothioneine (Ergo) is a naturally occurring dietary antioxidant. Ergo uptake is dependent on the transporter, organic cation transporter novel-type 1 (OCTN1) distribution. OCTN1 is highly expressed in blood cells (myeloid lineage cells), brain and ocular tissues that are likely predisposed to oxidative stress.

Longitudinal Consumption of Ergothioneine Reduces Oxidative Stress and Amyloid Plaques and Restores Glucose Metabolism in the 5XFAD Mouse Model of Alzheimer's Disease.

Ergothioneine (ERGO) is a unique antioxidant and a rare amino acid available in fungi and various bacteria but not in higher plants or animals. Substantial research data indicate that ERGO is a physiological antioxidant cytoprotectant. Different from other antioxidants that need to breach the blood-brain barrier to enter the brain parenchyma, a specialized transporter called OCTN1 has been identified for transporting ERGO to the brain.

Improved synthesis of an ergothioneine PET radioligand for imaging oxidative stress in Alzheimer's disease.

L-ergothioneine (ERGO) is a potent antioxidant with cytoprotective effects. To study ERGO biodistribution and detect oxidative stress in vivo, we report an efficient and reproducible preparation of [ C]-labeled ERGO PET radioligand based on protecting the histidine carboxylic group with a methyl ester. Overall, this new protection approach using methyl ester improved the chemical yield of a 4-step reaction from 14% to 24% compared to the previous report using t-butyl ester.

A novel antioxidant ergothioneine PET radioligand for in vivo imaging applications.

Ergothioneine (ERGO) is a rare amino acid mostly found in fungi, including mushrooms, with recognized antioxidant activity to protect tissues from damage by reactive oxygen species (ROS) components. Prior to this publication, the biodistribution of ERGO has been performed solely in vitro using extracted tissues. The aim of this study was to develop a feasible chemistry for the synthesis of an ERGO PET radioligand, [C]ERGO, to facilitate in vivo study.

Design, Synthesis, and Validation of a Novel [C]Promethazine PET Probe for Imaging Abeta Using Autoradiography.

Promethazine, an antihistamine drug used in the clinical treatment of nausea, has been demonstrated the ability to bind Abeta in a transgenic mouse model of Alzheimer's disease. However, so far, all of the studies were performed in vitro using extracted tissues. In this work, we report the design and synthesis of a novel [C]promethazine PET radioligand for future in vivo studies.