The bioactive role of omega-3 endocannabinoid epoxide regioisomers

Omega-3 polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), possess anti-inflammatory properties and are a source for bioactive lipid metabolites. Dietary EPA and DHA are converted to omega-3 endocannabinoids (eCBs), eicosapentaenoicethanolamide (EPEA) and docosahexaenoicethanolamide (DHEA), respectively. Subsequently, omega-3 eCBs are substrates for eicosanoid-synthesizing enzymes, cyclooxygenase, lipoxygenase and cytochrome P450 (CYP450) to generate novel oxygenated lipid mediators. Recently, CYP450 2J2 (CYP2J2) was found to metabolize EPEA to epoxyeicosatetraenoic-ethanolamide (EEQ-EAs) and DHEA to epoxydocosapentaenoic-ethanolamide (EDP-EAs) that are known as omega-3 eCB epoxides. Previously, 17,18-EEQ-EA and 19,20-EDP-EA have shown to have anti-neuroinflammatory, vasodilatory, anti-angiogenic properties, activate cannabinoid receptors and regulate platelet aggregation in vitro. Although these metabolites have demonstrated beneficial results, very few studies have investigated the biological and pharmacological action of the additional regioisomers such as EPEA epoxides, 14,15-EEQ-EA, 11,12-EEQ-EA, 8,9-EEQ-EA and DHEA epoxides, 16,17-EDP-EA, 13,14-EDP-EA, 10,11-EDP-EA and 7,8-EDP-EA. Hence, this dissertation reports the bioactive role of omega-3 eCB epoxide regioisomers generated by CYP450s regarding their anti-inflammatory properties and activation of cannabinoid receptors. We investigated the differential effect of the distinct omega-3 eCB epoxide regioisomers on cannabinoid receptor 1 (CB1) and cannabinoid receptor 2 (CB2) activation as well as neuroinflammation in BV-2 microglial cells. Our studies indicate that these eCB epoxides activate cannabinoid receptors with distinct receptor selectivity. They also show anti-inflammatory action by reducing nitrite production in lipopolysaccharide (LPS) stimulated BV-2 microglial cells in the presence and absence of soluble epoxide hydrolase (sEH) and fatty acid amide hydrolase (FAAH) inhibitors. Furthermore, we showed that two specific regioisomers 8,9-EEQ-EA and 13,14-EDP-EA, dose dependently reduced nitrite production and reduced levels of interleukin-6 (IL-6) in LPS stimulated BV-2 microglial cells. Lastly, we demonstrated that 8,9-EEQ-EA and 13,14-EDP-EA altered microglial phenotype by reducing proinflammatory mRNA levels of IL-6, inducible nitric oxide synthase (iNOS), tumour necrosis factor α (TNF-α) and monocyte chemoattractant protein-1 (MCP-1) as well as increasing anti-inflammatory mRNA levels of arginase-1 (Arg-1) in LPS stimulated BV-2 microglia. Collectively, we showed that omega-3 eCB epoxide regioisomers differentially activate cannabinoid receptors and are anti-neuroinflammatory in microglial cell culture models.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Biochemistry

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2020

Author dc:creator

• Lauderdale, Josephine Enales

Contributors dc:contributor

• Nair, Satish
• Gennis, Robert B
• Huang, Raven H
• Fratti, Rutilio A

• inflammation
• omega-3 fatty acids
• cannabinoid receptors
• endocannabinoids

Statement dc:rights

• Copyright 2020 Josephine Lauderdale

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/108554

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/108554