Drug Development.

Area of Science:

• Neuroscience
• Biochemistry
• Pharmacology

Background:

• Proteostasis maintains proteome stability via systems like the ubiquitin-proteasome system (UPS) and autophagy.
• Aging-related dysregulation of these pathways leads to neuronal protein aggregation, a hallmark of neurodegenerative diseases.
• While proteasome activation is studied, the UPS's role in clearing aggregate proteins presents a therapeutic target for Alzheimer's and other misfolding diseases.

Purpose of the Study:

• To synthesize and screen novel phenothiazine- and imidazoline-based small molecules for proteasome activation.
• To investigate the mechanism of proteasome activation, including binding sites and molecular interactions.
• To evaluate the therapeutic potential of these compounds in cellular and animal models of neurodegenerative diseases.

Main Methods:

• Synthesis and screening of small molecules in SH-SY5Y neuroblastoma cells.
• Computational simulations (docking, molecular dynamics) to predict binding to the proteasome.
• In vitro protein activity assays and cell viability tests across multiple cell lines.
• In vivo studies in APP/PS1 Alzheimer's disease mouse models.

Main Results:

• Small molecules selectively bound and activated the proteasome through gate-opening mechanisms.
• One compound demonstrated high efficacy, activating proteasome activity at nanomolar concentrations with no observed toxicity.
• In Alzheimer's mice, treatment reduced amyloid plaques, improved memory, and restored proteasome function.
• Compounds provided neuroprotection against oxidative stress in neuronal cells.

Conclusions:

• Direct proteasome activation via gate-opening is a novel therapeutic strategy for neurodegenerative diseases.
• Validated in cell and animal models, this approach reduces amyloid pathology and enhances neuroprotection.
• These findings support the development of proteasome activators as a promising therapeutic class.