“Recent studies have shown that inhibition of fatty acid amide hydrolase (FAAH), the major degradative enzyme of the endocannabinoid N-arachidonoylethanolamine (AEA), produced antidepressant behavioral responses, but its underlying mechanism is not clear. Here we find that a systemic administration of the FAAH inhibitor PF3845 or an intra-CA1 application of AEA elicits an in vivo long-term depression (LTD) at excitatory glutamatergic CA3-CA1 synapses of the hippocampus. The PF3845- and/or AEA-elicited LTD are abolished by the LTD-blocking peptide Tat-GluR2. PF3845 significantly decreases passive behavioral coping of naïve mice to acute inescapable stress, which is also abolished by Tat-GluR2 peptide. However, PF3845 does not significantly affect sucrose assumption ratio of mice receiving chronic administration of corticosterone. These results suggest that FAAH inhibitors are able to produce antidepressant effects in naïve animals in response to acute stress through LTD at hippocampal glutamatergic CA3-CA1 synapses.” https://www.ncbi.nlm.nih.gov/pubmed/28193523]]>
Tag Archives: fatty acid amide hydrolase (FAAH)
Fatty acid amide hydrolase inhibitors produce rapid anti-anxiety responses through amygdala long-term depression in male rodents.
CONCLUSION:
We propose that the rapid anti-anxiety effects of FAAH inhibition are due to AEA activation of astroglial CB1R and subsequent basolateral amygdala LTD in vivo.” https://www.ncbi.nlm.nih.gov/pubmed/28234213Constitutive Increases in Amygdalar Corticotropin-Releasing Factor and Fatty Acid Amide Hydrolase Drive an Anxious Phenotype.
“Corticotropin-releasing factor (CRF) mediates anxiogenic responses by activating CRF type 1 (CRF1) receptors in limbic brain regions. Anxiety is further modulated by the endogenous cannabinoid (eCB) system that attenuates the synaptic effects of stress. In the amygdala, acute stress activates the enzymatic clearance of the eCB N-arachidonoylethanolamine via fatty acid amide hydrolase (FAAH), although it is unclear whether chronic dysregulation of CRF systems induces maladaptive changes in amygdalar eCB signaling. Here, we used genetically selected Marchigian Sardinian P (msP) rats carrying an innate overexpression of CRF1receptors to study the role of constitutive upregulation in CRF systems on amygdalar eCB function and persistent anxiety-like effects.
Treatment with an FAAH inhibitor relieves sensitized glutamatergic responses in msPs and attenuates the anxiety-like phenotype. Pathological anxiety and stress hypersensitivity are driven by constitutive increases in CRF1 signaling that dysregulate N-arachidonoylethanolamine signaling mechanisms and reduce neuronal inhibitory control of CeA glutamatergic synapses.” https://www.ncbi.nlm.nih.gov/pubmed/28209423]]>A novel inhibitor of endocannabinoid catabolic enzymes sheds light on behind the scene interplay between chronic pain, analgesic tolerance, and heroin dependence.
“From the Aristotelian ancient Greece, pain has been associated with appetites or emotions and is opposite to pleasure. Reward and addiction is also linked to pleasure and compulsive drug seeking reinstates pleasure.
Alleviation of chronic pain can induce a euphoric phase similar to what is found in addiction. Both chronic pain and addiction are recognized as a disease of the central nervous system. They share many characteristics and brain regions/mechanisms.
Evidence points to the usefulness of cannabinoids as a new class of agents to add to the pharmaceutical toolbox in the management of chronic pain.
Wilkerson and colleagues, in this issue, examine SA-57, an inhibitor of two different endocannabinoid catabolic enzymes FAAH and MAGL, demonstrating its analgesic effectiveness and morphine-sparing properties in a chronic pain model, as well as its ability to reduce heroin seeking behavior in a self-administration paradigm in mice.
This timely study emphasizes the need for development of more efficacious chronic pain therapeutics with minimized abuse potential and/or reinforcing properties. It also highlights the need for better understanding of the overlapping circuitry of chronic pain, reward, and addiction.”
Revealing the role of the endocannabinoid system modulators, SR141716A, URB597 and VDM-11, in sleep homeostasis.
“The endocannabinoid system comprises receptors (CB1 and CB2 cannabinoid receptors), enzymes (Fatty Acid Amide Hydrolase [FAAH], which synthesizes the endocannabinoid anandamide), as well as the anandamide membrane transporter (AMT).
Importantly, previous experiments have demonstrated that the endocannabinoid system modulates multiple neurobiological functions, including sleep.
For instance, SR141716A (the CB1 cannabinoid receptor antagonist) as well as URB597 (the FAAH inhibitor) increase waking in rats whereas VDM-11 (the blocker of the AMT) enhances sleep in rodents. However, no further evidence is available regarding the neurobiological role of the endocannabinoid system in the homeostatic control of sleep.
Therefore, the aim of the current experiment was to test if SR141716A, URB597 or VDM-11 would modulate the sleep rebound after sleep deprivation. Thus, these compounds were systemically injected (5, 10, 20mg/Kg; ip; separately each one) to rats after prolonged waking. We found that SR141716A and URB597 blocked in dose-dependent fashion the sleep rebound whereas animals treated with VDM-11 displayed sleep rebound during the recovery period.
Complementary, injection after sleep deprivation of either SR141716A or URB597 enhanced dose-dependently the extracellular levels of dopamine, norepinephrine, epinephrine, serotonin, as well as adenosine while VDM-11 caused a decline in contents of these molecules.
These findings suggest that SR141716A or URB597 behave as a potent stimulants since they suppressed the sleep recovery period after prolonged waking.
It can be concluded that elements of the endocannabinoid system, such as the CB1 cannabinoid receptor, FAAH and AMT, modulate the sleep homeostasis after prolonged waking.”
Hemopressin peptides as modulators of the endocannabinoid system and their potential applications as therapeutic tools.
“The endocannabinoid system is activated by the binding of natural arachidonic acid derivatives (endogenous cannabinoids or endocannabinoids) as lipophilic messengers to cannabinoid receptors CB1 and CB2.
The endocannabinoid system comprises also many hydrolytic enzymes responsible for the endocannabinoids cleavage, such as FAAH and MAGL. These two enzymes are possible therapeutic targets for the development of new drugs as indirect cannabinoid agonists.
Recently a new family of endocannabinoid modulators was discovered; the lead of this family is the nonapeptide hemopressin produced from enzymatic cleavage of the α-chain of hemoglobin and acting as negative allosteric modulator of CB1. Hemopressin shows several physiological effects, e.g. antinociception, hypophagy, and hypotension. It is still matter of debate whether this peptide, isolated from the brain of rats is a real neuromodulator of the endocannabinoid system.
Recent evidence indicates that hemopressin could be a by-product formed by chemical degradation of a longer peptide RVD-hemopressin during the extraction from the brain homolysate. Indeed, RVD-hemopressin is more active than hemopressin in certain biological tests and may bind to the same subsite as Rimonabant, which is an inverse agonist for the CB1 receptor and a μ-opioid receptor antagonist.
These findings have stimulated several studies to verify this hypothesis and to evaluate possible therapeutic applications of hemopressin, its peptidic derivatives and synthetic analogues, opening new perspectives to the development of novel cannabinoid drugs.”
Dysregulation of the endocannabinoid signaling system in the cerebellum and brainstem in a transgenic mouse model of spinocerebellar ataxia type-3
“Spinocerebellar ataxia type-3 (SCA-3) is a rare disease but it is the most frequent type within the autosomal dominant inherited ataxias. The disease lacks an effective treatment to alleviate major symptoms and to modify disease progression.
Our recent findings that endocannabinoid receptors and enzymes are significantly altered in the post-mortemcerebellum of patients affected by autosomal-dominant hereditary ataxias suggest that targeting the endocannabinoid signaling system may be a promising therapeutic option.
Our goal was to investigate the status of the endocannabinoid signaling system in a transgenic mouse model of SCA-3, in the two CNS structures most affected in this disease –cerebellum and brainstem-.
These animals exhibited progressive motor incoordination, imbalance, abnormal gait, muscle weakness, and dystonia, in parallel to reduced in vivobrain glucose metabolism, deterioration of specific neuron subsets located in the dentate nucleus and pontine nuclei, small changes in microglial morphology, and reduction in glial glutamate transporters.
Concerning the endocannabinoid signaling, our data indicated no changes in CB2 receptors. By contrast, CB1 receptors increased in the Purkinje cell layer, in particular in terminals of basket cells, but they were reduced in the dentate nucleus.
We also measured the levels of endocannabinoid lipids and found reductions in anandamide and oleanolamideoyleth in the brainstem. These changes correlated with an increase in the FAAH enzyme in the brainstem, which also occurred in some cerebellar areas, whereas other endocannabinoid-related enzymes were not altered.
Collectively, our results in SCA-3 mutant mice confirm a possible dysregulation in the endocannabinoid system in the most important brain structures affected in this type of ataxia, suggesting that a pharmacological manipulation addressed to correct these changes could be a promising option in SCA-3.”
http://www.sciencedirect.com/science/article/pii/S0306452216305012
From Fertilisation to Implantation in Mammalian Pregnancy-Modulation of Early Human Reproduction by the Endocannabinoid System.
“There is an increasing recognition that the endocannabinoid system is the crucial cytokine-hormone system regulating early human pregnancy. The synchronous development of the fertilized embryo and the endometrium to ensure timely implantation has been shown to be one of the pivotal steps to successful implantation. This development is thought to be regulated by a finely balanced relationship between various components of the endocannabinoid system in the endometrium, the embryo and the Fallopian tube. In addition, this system has also been shown to be involved in the regulation of the development and maturation of the gametes prior to fertilization. In this review, we will examine the evidence from animal and human studies to support the role of the endocannabinoid system in gametogenesis, fertilization, implantation, early pregnancy maintenance, and in immunomodulation of pregnancy. We will discuss the role of the cannabinoid receptors and the enzymes involved in the synthesis and degradation of the key endocannabinoid ligands (e.g., anandamide and 2-arachinoylglycerol) in early reproduction.”
Dual-Acting Compounds Targeting Endocannabinoid and Endovanilloid Systems-A Novel Treatment Option for Chronic Pain Management.
“Compared with acute pain that arises suddenly in response to a specific injury and is usually treatable, chronic pain persists over time, and is often resistant to medical treatment.
Because of the heterogeneity of chronic pain origins, satisfactory therapies for its treatment are lacking, leading to an urgent need for the development of new treatments.
The leading approach in drug design is selective compounds, though they are often less effective and require chronic dosing with many side effects.
Herein, we review novel approaches to drug design for the treatment of chronic pain represented by dual-acting compounds, which operate at more than one biological target.
A number of studies suggest the involvement of the cannabinoid and vanilloid receptors in pain.
Interestingly cannabinoid system is in interrelation with other systems that comprise lipid mediators: prostaglandins, produced by COX enzyme.
Therefore, in the present review, we summarize the role of dual-acting molecules (FAAH/TRPV1 and FAAH/COX-2 inhibitors) that interact with endocannabinoid and endovanillinoid systems and act as analgesics by elevating the endogenously produced endocannabinoids and dampening the production of pro-inflammatory prostaglandins.
The plasticity of the endocannabinoid system (ECS) and the ability of a single chemical entity to exert an activity on two receptor systems has been developed and extensively investigated.
Here, we review up-to-date pharmacological studies on compounds interacting with FAAH enzyme together with TRPV1 receptor or COX-2 enzyme respectively.
Multi-target pharmacological intervention for treating pain may lead to the development of original and efficient treatments.”
Deficient Adolescent Social Behavior Following Early-Life Inflammation is Ameliorated by Augmentation of Anandamide Signaling.
“Early-life inflammation has been shown to exert profound effects on brain development and behavior, including altered emotional behavior, stress responsivity and neurochemical/neuropeptide receptor expression and function.
The current study extends this research by examining the impact of inflammation, triggered with the bacterial compound lipopolysaccharide (LPS) on postnatal day (P) 14, on social behavior during adolescence.
We investigate the role that the endocannabinoid (eCB) system plays in sociability after early-life LPS.
These data suggest that alterations in eCB signaling following postnatal inflammation contribute to impairments in social behavior during adolescence and that inhibition of FAAH could be a novel target for disorders involving social deficits such as social anxiety disorders or autism.”