Targeting Cellular Retinoic Acid Binding Protein 1 with Retinoic Acid-like Compounds to Mitigate Motor Neuron...

Area of Science:

• Neuroscience
• Molecular Biology
• Pharmacology

Background:

• All-trans-retinoic acid (atRA) has canonical (RAR-mediated) and non-canonical (CRABP1-mediated) activities.
• RAR-mediated toxicity limits clinical applications of atRA-like compounds.
• CRABP1 is a therapeutic target for motor neuron (MN) degenerative diseases due to its role in CaMKII signaling.

Purpose of the Study:

• To identify CRABP1-binding ligands lacking RAR activity.
• To investigate the role of CRABP1 and its ligands in MN differentiation and survival.
• To evaluate the therapeutic potential of CRABP1 ligands for MN degenerative diseases.

Main Methods:

• Utilized a P19-MN differentiation system to study CRABP1 ligands.
• Identified and characterized CRABP1-binding ligands C32 and C4.
• Assessed the impact of CRABP1 and ligands on CaMKII activation and MN excitotoxicity.

Main Results:

• C32 and C4 were confirmed as CRABP1 ligands modulating CaMKII activation during P19-MN differentiation.
• Elevating CRABP1 reduced excitotoxicity-triggered MN death, demonstrating a protective role.
• C32 and C4 ligands conferred protection against MN excitotoxicity.

Conclusions:

• CRABP1 ligands C32 and C4 effectively modulate CaMKII signaling in MNs.
• CRABP1 signaling plays a protective role in MN survival against excitotoxicity.
• Signaling pathway-selective, CRABP1-binding ligands offer potential for treating MN degenerative diseases.