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Methods for the Discovery of Novel Compounds Modulating a Gamma-Aminobutyric Acid Receptor Type A Neurotransmission
Published on: August 16, 2018
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Pharmacological characterization of the endocannabinoid sensor GRABeCB2.0
Simar Singh1,2,3, Dennis Sarroza1, Anthony English1,2,3
1Department of Pharmacology, University of Washington, Seattle, USA.
Biorxiv : the Preprint Server for Biology
|March 22, 2023
Summary
The GRABeCB2.0 sensor detects endocannabinoids (eCBs) and related compounds. Its response profile to various ligands, including phytocannabinoids like THC and CBD, was characterized to improve its utility in pharmacology research.
Area of Science:
- Neuroscience and Pharmacology
- Molecular Biology and Genetics
Background:
- Endocannabinoids (eCBs), such as 2-arachidonoylglycerol (2-AG) and arachidonoyl ethanolamine (AEA), are crucial signaling molecules with distinct pathways and receptor interactions.
- The genetically encoded sensor GRABeCB2.0 allows real-time monitoring of eCB levels, but its response to various analogues and phytocannabinoids is not fully characterized.
Approach:
- Expressed GRABeCB2.0 in HEK293 cells for live-cell confocal microscopy and high-throughput fluorescent signal measurements.
- Assessed the sensor's response to 2-AG, AEA, eCB analogues (2-LG, 2-OG), phytocannabinoids (THC), and synthetic agonists (CP55,940) and antagonists (SR141617).
Key Points:
- GRABeCB2.0 fluorescence signal correlated with the potencies of 2-AG and SR141617 at cannabinoid 1 receptors (CB1R).
- AEA, eCB analogues, and THC elicited responses with lower potencies than observed at CB1R.
- Cannabidiol (CBD) inhibited 2-AG-stimulated signals, indicating it retains CBD's negative allosteric modulator property at CB1R.
Conclusions:
- The study characterized the pharmacological profile of GRABeCB2.0, revealing differential responses to eCBs, analogues, and phytocannabinoids.
- This detailed profile enhances the interpretation of GRABeCB2.0 fluorescent signals in pharmacological studies, particularly for in vivo phytocannabinoid research.
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