Targeting the CSF-1/CSF-1R Axis: Exploring the Potential of CSF1R Inhibitors in Neurodegenerative Diseases

Area of Science:

• Neuroscience
• Pharmacology
• Medicinal Chemistry

Background:

• Neuroinflammation plays a critical role in the pathogenesis of neurodegenerative diseases, including Alzheimer's disease (AD).
• Colony-stimulating factor-1 receptor (CSF1R) is a key mediator of microglial activation and inflammatory responses in the brain.
• Targeting CSF1R presents a potential therapeutic strategy for managing neuroinflammatory conditions.

Purpose of the Study:

• To identify and characterize novel, selective inhibitors of CSF1R for potential therapeutic applications in neuroinflammatory diseases.
• To evaluate the efficacy of these inhibitors in preclinical models of neuroinflammation.

Main Methods:

• Synthesis and chemical modification of a novel scaffold, N-(4-heterocycloalkyl-2-cycloalkylphenyl)-5-methylisoxazole-3-carboxamide.
• In silico molecular docking studies to predict binding modes within the CSF1R.
• Kinome-wide selectivity profiling to assess target specificity.
• In vitro assays to determine cellular activity, cytotoxicity, and CSF1R phosphorylation inhibition in microglial cells.
• In vivo studies using an LPS-induced neuroinflammation model.

Main Results:

• Identification of highly selective and potent CSF1R inhibitors, specifically compounds 7dr and 7ds.
• Compound 7dr demonstrated excellent selectivity for CSF1R over other kinases.
• 7dr exhibited favorable cellular activity with minimal cytotoxicity.
• Inhibition of CSF1R phosphorylation in microglial cells was observed.
• Significant mitigation of neuroinflammation was achieved in an in vivo LPS-induced model.

Conclusions:

• Compound 7dr is a potent CSF1R inhibitor with demonstrated antineuroinflammatory effects.
• The identified inhibitors hold significant promise as therapeutic agents for neuroinflammatory diseases, particularly Alzheimer's disease.
• Further investigation into 7dr is warranted for its clinical development in treating neuroinflammation.