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Knockdown siRNA Targeting GPR55 Reveals Significant Differences Between the Anti-inflammatory Actions of KLS-13019
Douglas E Brenneman1, William A Kinney2, Mark E McDonnell2
1Kannalife Sciences, Inc, Pennsylvania Biotechnology Center, 3805 Old Easton Road, Doylestown, PA, 18902, USA. doug@kannalife.com.
Abstract:
KLS-13019 was reported previously to reverse paclitaxel-induced mechanical allodynia in a mouse model of chemotherapy-induced peripheral neuropathy (CIPN). Recent studies demonstrated that paclitaxel-induced increases in inflammatory markers (GPR55, NLRP3, and IL-1β) of dorsal root ganglion (DRG) cultures were shown to be reversed by KLS-13019 treatment. The mechanism of action for KLS-13019-mediated reversal of paclitaxel-induced neuroinflammation now has been explored using GPR55 siRNA. Pre-treatment of DRG cultures with GPR55 siRNA produced a 21% decrease of immunoreactive (IR) area for GPR55 in cell bodies and a 59% decrease in neuritic IR area, as determined by high-content imaging. Using a 24-h reversal treatment paradigm, paclitaxel-induced increases in the inflammatory markers were reversed back to control levels after KLS-3019 treatment. Decreases in these inflammatory markers produced by KLS-13019 were significantly attenuated by GPR55 siRNA co-treatment, with mean IR area responses being attenuated by 56% in neurites and 53% in cell bodies. These data indicate that the percentage decreases in siRNA-mediated attenuation of KLS-13019-related efficacy on the inflammatory markers were similar to the percentage knockdown observed for neuritic GPR55 IR area. Similar studies conducted with cannabidiol (CBD), the parent compound of KLS-13019, produced low efficacy (25%) reversal of all inflammatory markers that were poorly attenuated (29%) by GPR55 siRNA. CBD was shown previously to be ineffective in reversing paclitaxel-induced mechanical allodynia. The present studies indicated significant differences between the anti-inflammatory properties of KLS-13019 and CBD which may play a role in their observed differences in the reversibility of mechanical allodynia in a mouse model of CIPN.
Insights
KLS-13019 effectively reverses chemotherapy-induced nerve pain by reducing inflammatory markers in dorsal root ganglion cultures. Its mechanism involves GPR55, unlike its parent compound CBD, highlighting KLS-13019
Area of Science:
- Neuroscience
- Pharmacology
- Molecular Biology
Background:
- Chemotherapy-induced peripheral neuropathy (CIPN) causes debilitating mechanical allodynia.
- Paclitaxel treatment increases inflammatory markers like GPR55, NLRP3, and IL-1β in dorsal root ganglion (DRG) cultures.
- KLS-13019 has previously shown efficacy in reversing paclitaxel-induced allodynia and neuroinflammation.
Purpose of the Study:
- To elucidate the mechanism of action for KLS-13019's reversal of paclitaxel-induced neuroinflammation.
- To investigate the role of G protein-coupled receptor 55 (GPR55) in KLS-13019's anti-inflammatory effects.
- To compare the anti-inflammatory properties and efficacy of KLS-13019 with its parent compound, cannabidiol (CBD).
Main Methods:
- Dorsal root ganglion (DRG) cultures were treated with GPR55 siRNA to assess GPR55 knockdown.
- High-content imaging was used to quantify immunoreactive (IR) areas of GPR55 in cell bodies and neurites.
- Cultures were treated with paclitaxel, followed by KLS-13019 or CBD, with or without GPR55 siRNA co-treatment.
Main Results:
- GPR55 siRNA pre-treatment significantly reduced GPR55 expression in DRG cultures.
- KLS-13019 treatment reversed paclitaxel-induced increases in inflammatory markers (GPR55, NLRP3, IL-1β) to control levels.
- GPR55 siRNA co-treatment significantly attenuated the anti-inflammatory effects of KLS-13019, indicating GPR55's crucial role.
- Cannabidiol (CBD) showed limited efficacy in reversing inflammatory markers and was poorly attenuated by GPR55 siRNA.
Conclusions:
- KLS-13019 exerts its anti-neuroinflammatory effects, at least in part, through interaction with GPR55.
- The mechanism of action of KLS-13019 differs from that of CBD, explaining their distinct efficacies in reversing CIPN-related allodynia.
- These findings support KLS-13019 as a potential therapeutic agent for managing chemotherapy-induced peripheral neuropathy.
