Tag Archives: endocannabinoid system

Inhibition of endocannabinoid degradation rectifies motivational and dopaminergic deficits in the Q175 mouse model of Huntington’s disease.

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“Prominent motor deficits (e.g., chorea) that typify Huntington’s disease (HD) arise following a prolonged prodromal stage characterized by psychiatric disturbances. Apathy, a disorder of motivation characterized by diminished goal-directed behavior, is one of the earliest and most common psychiatric symptoms in HD, but the underlying neurobiology is unclear and treatment options are limited.

Alterations in the endocannabinoid (eCB) and dopamine systems represent prominent pathophysiological markers in HD that-similar to motivational deficits-present early and decline across disease progression. Whether changes in dopamine and eCB systems are associated with specific behavioral impairments in HD and whether these deficits are amenable to viable treatments is unknown.

Here, we show that dopaminergic encoding of effortful drive progressively declines with age in an HD mouse model, and is restored by elevating tissue levels of the eCB 2-arachidonoylglycerol (2-AG) through targeted inhibition of its enzymatic degradation.

This work supports aberrant dopaminergic encoding of reward as a neurobiological correlate of apathy in HD, and indicates that cannabinoid receptor-based therapies may benefit neuropsychiatric care for HD.”

https://www.ncbi.nlm.nih.gov/pubmed/29925886

https://www.nature.com/articles/s41386-018-0107-8

Medicinal Cannabinoids in Palliative Care.

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“The treatment of symptoms in people with palliative diagnoses begins with meticulous clinical assessment with treatment choice (s) selected based on an understanding of the symptom aetiology and the evidence which underpins its treatment.

Increasingly the merits of palliative care have been established earlier in the disease trajectory where treatment outcomes may include increased survival and maintenance of function.

There is strong public support for the availability of medicinal cannabis, particularly for people with palliative diagnoses.

There are several areas where there is potential for symptom benefits through modulation of the endocannabinoid system, though clinical data to date has been inconclusive in key symptoms such as pain and nausea, and data from other settings such as chemotherapy-induced nausea and vomiting not readily extrapolated.

Ideally exploration of medicinal cannabinoids should occur within a clinical trial to accelerate the evidence base to inform practice. In people with refractory symptoms the consideration of unregistered products or off label prescribing should be guided by the potential influences of pharmacokinetic, pharmacodynamic and drug-drug interactions, supported by an informed discussion with the patient, and regular review of net clinical benefit.”

https://www.ncbi.nlm.nih.gov/pubmed/29923616

https://bpspubs.onlinelibrary.wiley.com/doi/abs/10.1111/bcp.13671

The Role of Cannabinoids in the Setting of Cirrhosis.

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“Although the mortality rates of cirrhosis are underestimated, its socioeconomic burden has demonstrated a significant global impact. Cirrhosis is defined by the disruption of normal liver architecture after years of chronic insult by different etiologies. Treatment modalities are recommended primarily in decompensated cirrhosis and specifically tailored to the different manifestations of hepatic decompensation. Antifibrogenic therapies are within an active area of investigation.

The endocannabinoid system has been shown to play a role in liver disease, and cirrhosis specifically, with intriguing possible therapeutic benefits. The endocannabinoid system comprises cannabinoid receptors 1 (CB1) and cannabinoid receptor 2 (CB2) and their ligands, endocannabinoids and exocannabinoids.

CB1 activation enhances fibrogenesis, whereas CB2 activation counteracts progression to fibrosis. Conversely, deletion of CB1 is associated with an improvement of hepatic fibrosis and steatosis, and deletion of CB2 results in increased collagen deposition, steatosis, and enhanced inflammation.

CB1 antagonism has also demonstrated vascular effects in patients with cirrhosis, causing an increase in arterial pressure and vascular resistance as well as a decrease in mesenteric blood flow and portal pressure, thereby preventing ascites. In mice with hepatic encephalopathy, CB1 blockade and activation of CB2 demonstrated improved neurologic score and cognitive function.

Endocannabinoids, themselves also have mechanistic roles in cirrhosis. Arachidonoyl ethanolamide (AEA) exhibits antifibrogenic properties by inhibition of HSC proliferation and induction of necrotic death. AEA induces mesenteric vasodilation and hypotension via CB1 induction. 2-arachidonoyl glycerol (2-AG) is a fibrogenic mediator independent of CB receptors, but in higher doses induces apoptosis of HSCs, which may actually show antifibrotic properties. 2-AG has also demonstrated growth-inhibitory and cytotoxic effects.

The exocannabinoid, THC, suppresses proliferation of hepatic myofibroblasts and stellate cells and induces apoptosis, which may reveal antifibrotic and hepatoprotective mechanisms. Thus, several components of the endocannabinoid system have therapeutic potential in cirrhosis.”

https://www.ncbi.nlm.nih.gov/pubmed/29890719

http://www.mdpi.com/2305-6320/5/2/52

Betacaryophyllene – A phytocannabinoid as potential therapeutic modality for human sepsis?

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Medical Hypotheses Home

“Sepsis is a clinical condition resulting from a dysregulated immune response to an infection that leads to organ dysfunction. Despite numerous efforts to optimize treatment, sepsis remains to be the main cause of death in most intensive care units.

The endogenous cannabinoid system (ECS) plays an important role in inflammation.

Cannabinoid receptor 2 (CB2R) activation is immunosuppressive, which might be beneficial during the hyper-inflammatory phase of sepsis.

Beta-caryophyllene (BCP) is a non-psychoactive natural cannabinoid (phytocannabinoid) found in Cannabis sativa and in essential oils of spices and food plants, that acts as a selective agonist of CB2R.

We propose BCP administration as novel treatment to reduce hyper-inflammation in human sepsis.”

 https://www.ncbi.nlm.nih.gov/pubmed/29317072
https://www.medical-hypotheses.com/article/S0306-9877(17)30861-7/fulltext

Ischemia/Reperfusion Model Impairs Endocannabinoid Signaling and Na+/K+ ATPase Expression and Activity in Kidney Proximal Tubule Cells.

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“LLC-PK1 cells, an immortalized epithelial cell line derived from pig renal proximal tubules, express all the major players of the endocannabinoid system (ECS) such as CB1, CB2 and TRPV1 receptor, as well as the main enzymes involved in the biosynthesis and degradation of the major endocannabinoids named 2-arachidonoylglycerol, 2-AG and anandamide, AEA.

Here we investigated whether the damages caused by ischemic insult either in vitro using LLC-PK1 cells exposed to antimycin A (an inductor of ATP-depletion) or in vivo using Wistar rats in a classic renal ischemia and reperfusion (IR) protocol, lead to changes in AEA and 2-AG levels, as well as altered expression of genes from the main enzymes involved in the regulation of the ECS.

Our data show that the mRNA levels of CB1 receptor gene were downregulated, while the transcript levels of monoacylglycerol lipase (MAGL), the main 2-AG degradative enzyme, are upregulated in LLC-PK1 cells after IR model. Accordingly, IR was accompanied by a significant reduction in the levels of 2-AG and AEA, as well as of the two endocannabinoid related molecules, oleoylethanolamide (OEA) and palmitoylethanolamide (PEA) in LLC-PK1 cells. In kidney cortex homogenates, the AEA levels were selectively significantly decreased. In addition, we found that both the in vitro and in vivo model of IR caused a reduction in the expression and activity of the Na+/K+ATPase. These changes were reversed by the CB1/CB2 agonist WIN55,212, in a CB1-receptor dependent manner on LLC-PK1 IR model.

In conclusion, the ECS and Na+/K+ ATPase are down-regulated following IR model in LLC-PK1 cells and rat kidney. We suggest that CB1 agonists might represent a potential strategy to reverse the consequences of IR injury in kidney tissues.”

https://www.ncbi.nlm.nih.gov/pubmed/29890144

https://www.sciencedirect.com/science/article/pii/S0006295218302132

The Lateral Habenula Directs Coping Styles Under Conditions of Stress Via Recruitment of the Endocannabinoid System.

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Biological Psychiatry Home

“The ability to effectively cope with stress is a critical determinant of disease susceptibility.

The lateral habenula (LHb) and the endocannabinoid (ECB) system have independently been shown to be involved in the selection of stress coping strategies, yet the role of ECB signaling in the LHb remains unknown.

CONCLUSIONS:

Alterations in LHb ECB signaling may be relevant for development of stress-related pathologies in which LHb dysfunction and stress-coping impairments are hallmark symptoms.”

https://www.ncbi.nlm.nih.gov/pubmed/29887035

https://www.biologicalpsychiatryjournal.com/article/S0006-3223(18)31473-2/fulltext

“Cannabinoids reverse the effects of early stress on neurocognitive performance in adulthood.” https://www.ncbi.nlm.nih.gov/pubmed/27317195

Activation of GPR55 increases neural stem cell proliferation and promotes early adult hippocampal neurogenesis

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“The cannabinoid system exerts functional regulation of neural stem cell (NSC) proliferation and adult neurogenesis, yet not all effects of cannabinoid-like compounds seen can be attributed to the cannabinoid 1 receptor (CB1 R) or cannabinoid 2 receptor (CB2 R).

The recently de-orphaned GPR55 has been shown to be activated by numerous cannabinoid ligands suggesting that GPR55 is a third cannabinoid receptor.

Here we examined the role of GPR55 activation in NSC proliferation and early adult neurogenesis.

CONCLUSIONS AND IMPLICATIONS:

Together, these findings suggest GPR55 activation as a novel target and strategy to regulate NSC proliferation and adult neurogenesis.”

https://www.ncbi.nlm.nih.gov/pubmed/29888782

https://bpspubs.onlinelibrary.wiley.com/doi/abs/10.1111/bph.14387

“The orphan receptor GPR55 is a novel cannabinoid receptor”  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2095107/

Probing the endocannabinoid system in healthy volunteers: Cannabidiol alters fronto-striatal resting-state connectivity.

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European Neuropsychopharmacology Home

“Tetrahydrocannabinol (THC) and Cannabidiol (CBD) are two substances from cannabis sativa that have been implicated in the treatment of mental and neurological disorders.

We concentrated on a previously validated neuroimaging phenotype, fronto-striatal connectivity across different striatal seeds, because of this loop’s relevance to executive functioning, decision making, salience generation and motivation and its link to various neuropsychiatric conditions. Therefore, we studied the effect of THC and CBD on fronto-striatal circuitry by a seed-voxel connectivity approach using seeds from the caudate and the putamen.

We conducted a cross-over pharmaco-fMRI study in 16 healthy male volunteers with placebo, 10 mg oral THC and 600 mg oral CBD. Resting state was measured in a 3 T scanner. CBD lead to an increase of fronto-striatal connectivity in comparison to placebo.

In contrast to our expectation that THC and CBD show opposing effects, THC versus placebo did not show any significant effects, probably due to insufficient concentration of THC during scanning.

The effect of CBD on enhancing fronto-striatal connectivity is of interest because it might be a neural correlate of its anti-psychotic effect in patients.”

https://www.ncbi.nlm.nih.gov/pubmed/29887287
https://www.europeanneuropsychopharmacology.com/article/S0924-977X(18)30113-5/fulltext

The relationship of endocannabinoidome lipid mediators with pain and psychological stress in women with fibromyalgia – a case control study.

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“Characterized by chronic widespread pain, generalized hyperalgesia, and psychological stress fibromyalgia (FM) is difficult to diagnose and lacks effective treatments.

The endocannabinoids – arachidonoylethanolamide (AEA), 2-arachidonoylglycerol (2-AG), and the related oleoylethanolamide (OEA), palmitoylethanolamide (PEA), and stearoylethanolamide (SEA) – are endogenous lipid mediators with analgesic and anti-inflammatory characteristics, in company with psychological modulating properties (e.g., stress and anxiety), and are included in a new emerging “ome”, the endocannabinoidome.

This case -control study compared the concentration differences of AEA, OEA, PEA, SEA, and 2-AG in 104 women with FM and 116 healthy controls (CON). All participants OEArated their pain, anxiety, depression, and current health status. The relationships between the lipid concentrations and the clinical assessments were investigated using powerful multivariate data analysis and traditional bivariate statistics. The concentrations of OEA, PEA, SEA, and 2-AG were significantly higher in FM than in CON; significance remained for OEA and SEA after controlling for BMI and age. 2-AG correlated positively with FM duration and BMI, and to some extent negatively with pain, anxiety, depression, and health status. In FM, AEA correlated positively with depression ratings.

The elevated circulating levels of endocannabinoidome lipids suggest that these lipids play a role in the complex pathophysiology of FM and might be signs of ongoing low-grade inflammation in FM. Although the investigated lipids are significantly altered in FM their biological roles are uncertain with respect to the clinical manifestations of FM. Thus, plasma lipids alone are not good biomarkers for FM.

PERSPECTIVE:

This study reports about elevated plasma levels of endocannabinoidome lipid mediators in FM. The lipids suitability to work as biomarkers for FM in the clinic were low, however their altered levels indicate that a metabolic asymmetry is ongoing in FM, which could serve as basis during explorative FM pain management.”

https://www.ncbi.nlm.nih.gov/pubmed/29885369

https://www.jpain.org/article/S1526-5900(18)30197-4/fulltext

Cannabinoid receptor type 1 in the brain regulates the affective component of visceral pain in mice.

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“Endocannabinoids acting through cannabinoid receptor type 1 (CB1) are major modulators of peripheral somatic and visceral nociception. Although only partially studied, some evidence suggests a particular role of CB1 within the brain in nociceptive processes.

As the endocannabinoid system regulates affect and emotional behaviors, we hypothesized that cerebral CB1 influences affective processing of visceral pain-related behaviors in laboratory animals.

To study nocifensive responses modulated by supraspinal CB1, we used conditional knock-out mice lacking CB1 either in cortical glutamatergic neurons (Glu-CB1-KO), or in forebrain GABAergic neurons (GABA-CB1-KO), or in principle neurons of the forebrain (CaMK-CB1-KO). These mutant mice and mice treated with the CB1 antagonist SR141716 were tested for different pain-related behaviors. In an acetic acid-induced abdominal constriction test, supraspinal CB1 deletions did not affect nocifensive responses. In the cerulein-model of acute pancreatitis, mechanical allodynia or hyperalgesia were not changed, but Glu-CB1- and CaMK-CB1-KO mice showed significantly increased facial grimacing scores indicating increased affective responses to this noxious visceral stimulus. Similarly, these brain-specific CB1 KO mice also showed significantly changed thermal nociception in a hot-plate test.

These results reveal a novel, and important role of CB1 expressed by cortical glutamatergic neurons in the affective component of visceral nociception.”

https://www.ncbi.nlm.nih.gov/pubmed/29885522

https://www.sciencedirect.com/science/article/pii/S0306452218303919