2-Arachidonoylglycerol: A signaling lipid with manifold actions in the brain.

Cover image

“2-Arachidonoylglycerol (2-AG) is a signaling lipid in the central nervous system that is a key regulator of neurotransmitter release. 2-AG is an endocannabinoid that activates the cannabinoid CB1 receptor. It is involved in a wide array of (patho)physiological functions, such as emotion, cognition, energy balance, pain sensation and neuroinflammation. In this review, we describe the biosynthetic and metabolic pathways of 2-AG and how chemical and genetic perturbation of these pathways has led to insight in the biological role of this signaling lipid. Finally, we discuss the potential therapeutic benefits of modulating 2-AG levels in the brain.”

Human bone marrow mesenchymal stem cells secrete endocannabinoids that stimulate in vitro hematopoietic stem cell migration effectively comparable to beta adrenergic stimulation.

Experimental Hematology Home

“Granulocyte Colony-Stimulating Factor (G-CSF) is a well-known hematopoietic stem cell (HSC) mobilizing agent used in both allogeneic and autologous transplantation. However, a proportion of patients or healthy donors fail to mobilize sufficient number of cells. New mobilization agents are therefore needed.

Endocannabinoids (eCBs) are endogenous lipid mediators generated in the brain and peripheral tissues and activate the cannabinoid receptors (CB1, CB2). We suggest that eCBs may act as mobilizers of hematopoietic stem cells (HSC) from the BM under stress conditions as beta adrenergic receptors (Adrβ).

This study demonstrates that bone marrow (BM) mesenchymal stem cells (MSCs) secrete anandamide (AEA) and 2-arachidonylglycerol (2-AG), and peripheral blood (PB) and BM microenvironment contain AEA and 2-AG. 2-AG levels are significantly higher in PB of the G-CSF treated group when compared to BM plasma. BM mononuclear cells (MNCs) and CD34+HSCs, express CB1, CB2 and Adrβ subtypes. CD34+HSCs had higher CB1 and CB2 receptor expression in G-CSF untreated and treated groups when compared to MSCs. MNCs but not MSCs expressed CB1 and CB2 receptors based on qRT-PCR and flow cytometry (FC). AEA and 2-AG stimulated HSC migration was blocked by eCB receptor antagonists in in vitro migration assay.

In conclusion, components of the eCB system and their interaction with Adrβ subtypes were demonstrated on HSCs and MSCs of G-CSF treated and untreated healthy donors in vitro, revealing that eCBs might be potential candidates to enhance or facilitate G-CSF-mediated HSC migration under stress conditions in a clinical setting.”

https://www.ncbi.nlm.nih.gov/pubmed/29030083

http://www.exphem.org/article/S0301-472X(17)30813-5/fulltext

2-Arachidonylglycerol, an endogenous cannabinoid, inhibits tumor necrosis factor-alpha production in murine macrophages, and in mice.

Image result for Eur J Pharmacol.

“2-Arachidonylglycerol (2-AG) inhibits the production in vitro of tumor necrosis factor-alpha (TNF-alpha) by mouse macrophages, as well as in mice. It has no effect on the production of nitric oxide (NO). The effect on TNF-alpha is enhanced when 2-AG is administered together with 2-linoleylglycerol (2-Lino-G) and 2-palmitylglycerol (2-PalmG), an ‘entourage effect’ previously noted in several behavioral and binding assays. 2-AG also suppresses the formation of radical oxygen intermediates.”

Cannabinoids and Neuroprotection in Stroke

“One of the most recently described neural signaling systems is that mediated by endogenous cannabinoids (endocannabinoids). Cannabinoids have recently been shown to attenuate neuronal injury induced by hypoxia and glucose deprivation in cell culture, as well as injury induced in rat brain following both global and focal cerebral ischemia in vivo.

Two endocannabinoids have been characterized in detail: N-arachidonylethanolamide and 2-arachidonylglycerol. Cannabinoid CB1 and CB2receptors have been cloned and an alternatively spliced CB1A isoform has been identified.

The development of metabolically stable, synthetic, enantiomeric cannabinoid receptor agonists and of CB1 and CB2 receptor antagonists has greatly aided the characterization of cannabinoid receptor-mediated processes, although certain aspects of cannabinoid signaling in some systems remain poorly understood.

Indirect evidence suggests that cannabinoids might serve as endogenous regulators of ischemic neuronal injury, but several recent reports provide more direct evidence bearing on such a role.

The author’s own findings provide evidence for CB1 receptor-mediated neuroprotection in vivo, but non-receptor-mediated protection in vitro.”

http://journals.prous.com/journals/servlet/xmlxsl/pk_journals.xml_summary_pr?p_JournalId=3&p_RefId=129&p_IsPs=Y

[The modulatory role of endocannabinoids in sleep].

“The endogenous cannabinoid, or endocannabinoid, system is present in the central nervous system (CNS) of rodents and humans. This system includes receptors, endogenous ligands and enzymes. The presence of cannabinoid receptors, called CB1, in the CNS has been reported in the cerebral cortex, the hippocampus, the cerebellum and the brain stem. This neuroanatomical location suggests that this receptor could modify several physiological functions, such as the consolidation of memory, motor control and the generation of sleep.

 

Recent reports have described the presence of lipids in the CNS that bind to the CB1 receptor. Administration of said molecules induces cannabimimetic effects, and hence it has been suggested that these lipids are endogenous cannabinoids or endocannabinoids. Anandamide, 2-arachidonylglycerol, virodhamine, noladin ether and N-arachidonyldopamine are molecules that belong to the endocannabinoid family. Anandamide has received more attention from researchers because it was the first endocannabinoid to be reported. Pharmacological experiments have shown that this endocannabinoid induces several different intracellular and behavioural changes.

CONCLUSIONS:

In this study, we review the most important pharmacological aspects of exogenous cannabinoids and the neurobiological role played by the endocannabinoid system, including endogenous and exogenous ligands and receptors. We also examine their pharmacological effects on different behaviours, with particular attention given to the modulation of sleep.”

http://www.ncbi.nlm.nih.gov/pubmed/18297624