Category Archives: Endocannabinoid System

Activation of Cannabinoid CB2 receptors Reduces Hyperalgesia in an Experimental Autoimmune Encephalomyelitis Mouse Model of Multiple Sclerosis.

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“Clinical trials investigating the analgesic efficacy of cannabinoids in multiple sclerosis have yielded mixed results, possibly due to psychotropic side effects mediated by cannabinoid CB1 receptors. We hypothesized that a CB2-specific agonist (JWH-133) would decrease hyperalgesia in an experimental autoimmune encephalomyelitis mouse model of multiple sclerosis…

Our results suggest that JWH-133 acts at CB2 receptors, most likely within the dorsal horn of the spinal cord, to suppress the hypersensitivity associated with experimental autoimmune encephalomyelitis.

These are the first pre-clinical studies to directly promote CB2 as a promising target for the treatment of central pain in an animal model of multiple sclerosis.”

http://www.ncbi.nlm.nih.gov/pubmed/25849525

The role of the endocannabinoid system in pain.

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“Preparations of the Cannabis sativa plant have been used to analgesic effect for millenia, but only in recent decades has the endogenous system responsible for these effects been described.

The endocannabinoid (EC) system is now known to be one of the key endogenous systems regulating pain sensation, with modulatory actions at all stages of pain processing pathways.

The EC system is composed of two main cannabinoid receptors (CB1 and CB2) and two main classes of endogenous ligands or endocannabinoids (ECs).

The receptors have distinct expression profiles, with CB1 receptors found at presynaptic sites throughout the peripheral and central nervous systems (PNS and CNS, respectively), whilst CB2 receptor is found principally (but not exclusively) on immune cells.

The endocannabinoid ligands are lipid neurotransmitters belonging to either the N-acyl ethanolamine (NAEs) class, e.g. anandamide (AEA), or the monoacylglycerol class, e.g. 2-arachidonoyl glycerol (2-AG).

Both classes are short-acting transmitter substances, being synthesised on demand and with signalling rapidly terminated by specific enzymes. ECs acting at CB1 negatively regulate neurotransmission throughout the nervous system, whilst those acting at CB2 regulate the activity of CNS immune cells.

Signalling through both of these receptor subtypes has a role in normal nociceptive processing and also in the development resolution of acute pain states.

In this chapter, we describe the general features of the EC system as related to pain and nociception and discuss the wealth of preclinical and clinical data involving targeting the EC system with focus on two areas of particular promise: modulation of 2-AG signalling via specific enzyme inhibitors and the role of spinal CB2 in chronic pain states.”

http://www.ncbi.nlm.nih.gov/pubmed/25846617

http://www.thctotalhealthcare.com/category/pain-2/

Major urinary protein 1 interacts with cannabinoid receptor type 1 in fatty acid-induced hepatic insulin resistance in a mouse hepatocyte model.

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“Hepatic insulin resistance (HIR) is a metabolic abnormality characterized by increased gluconeogenesis which usually contributes from an elevation of free fatty acids.

Cannabinoid receptor type 1 (CB1R) and major urinary protein 1 (MUP1) are thought to play pivotal roles in mitochondrial dysfunction, liver steatosis and insulin resistance.

The aim of this study was to explore the role of MUP1 in CB1R-mediated HIR through the dysregulation of mitochondrial function in AML12 mouse hepatocytes challenged with high concentration of free fatty acids (HFFA)…

Altogether, these findings suggest that the anti-HIR effect of AM251 via improvement of mitochondrial functions might occur in a MUP1-dependent manner.”

http://www.ncbi.nlm.nih.gov/pubmed/25843798

The interactive role of cannabinoid and vanilloid systems in hippocampal synaptic plasticity in rats.

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“Long-term potentiation (LTP) has been most thoroughly studied in the hippocampus, which has a key role in learning and memory. Endocannabinoids are one of the endogenous systems that modulate this kind of synaptic plasticity. The activation of the vanillioid system has also been shown to mediate synaptic plasticity in the hippocampus. In addition, immunohistochemical studies have shown that cannabinoid receptor type 1 (CB1) and vanilloid receptor 1 (TRPV1) are closely located in the hippocampus.

It seems that agonists of the vanilloid system modulate cannabinoid outputs that cause an increase in synaptic plastisity, while in contemporary consumption of two agonist, TRPV1 agonist can change production of endocannabinoid, which in turn result to enhancement of LTP induction. These findings suggest that the two systems may interact or share certain common signaling pathways in the hippocampus.”

http://www.ncbi.nlm.nih.gov/pubmed/25843413

Localization and production of peptide endocannabinoids in the rodent CNS and adrenal medulla.

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“The endocannabinoid system (ECS) comprises the cannabinoid receptors CB1 and CB2 and their endogenous arachidonic acid-derived agonists 2-arachidonoyl glycerol and anandamide, which play important neuromodulatory roles.

Recently, a novel class of negative allosteric CB1 receptor peptide ligands, hemopressin-like peptides derived from alpha hemoglobin, has been described, with yet unknown origin and function in the CNS. Using monoclonal antibodies we now identified the localization of RVD-hemopressin (pepcan-12) and N-terminally extended peptide endocannabinoids (pepcans) in the CNS and determined their neuronal origin…

These data uncover important areas of peptide endocannabinoid occurrence with exclusive noradrenergic immunohistochemical staining, opening new doors to investigate their potential physiological function in the ECS.”

http://www.ncbi.nlm.nih.gov/pubmed/25839900

Increased Cerebral Cannabinoid-1 Receptor Availability Is a Stable Feature of Functional Dyspepsia: A [F]MK-9470 PET Study.

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“Functional dyspepsia (FD) is a prevalent functional gastrointestinal disorder (FGID) defined by chronic epigastric symptoms in the absence of organic abnormalities likely to explain them. Comorbidity with mood and anxiety disorders as well as with other FGIDs and functional somatic syndrome (FSS) is high. FD is characterized by abnormal regional cerebral activity in cognitive/affective pain modulatory circuits, but it is unknown which neurotransmitter systems are involved.

The authors aimed to assess and compare in vivo cerebral cannabinoid-1 (CB1) receptor availability between FD patients and age-, gender- and BMI-matched healthy controls (HC).

FD patients had significantly higher CB1 receptor availability in the cerebral regions involved in (visceral) nociception (brainstem, insula, anterior cingulate cortex) as well as in the homeostatic and hedonic regulation of food intake [hypothalamus, (ventral) striatum]….

Although these findings need replication in larger samples, they suggest that the abnormal brain activity in several of these regions, previously demonstrated in FD, may be due to a sustained endocannabinoid system dysfunction, identifying it as a potential novel target for treatment and warranting further studies to elucidate whether it is also a feature of other FGIDs or FSSs.”

http://www.ncbi.nlm.nih.gov/pubmed/25833408

Minocycline Attenuates Neonatal Germinal-Matrix-Hemorrhage-Induced Neuroinflammation and Brain Edema by Activating Cannabinoid Receptor 2.

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“Germinal matrix hemorrhage (GMH) is the most common neurological disease of premature newborns leading to detrimental neurological sequelae.

Minocycline has been reported to play a key role in neurological inflammatory diseases by controlling some mechanisms that involve cannabinoid receptor 2 (CB2R). The current study investigated whether minocycline reduces neuroinflammation and protects the brain from injury in a rat model of collagenase-induced GMH by regulating CB2R activity…

Our study demonstrates, for the first time, that minocycline attenuates neuroinflammation and brain injury in a rat model of GMH, and activation of CBR2 was partially involved in these processes.”

Endocannabinoid signaling in innate and adaptive immunity.

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“The immune system can be modulated and regulated not only by foreign antigens but also by other humoral factors and metabolic products, which are able to affect several quantitative and qualitative aspects of immunity.

Among these, endocannabinoids are a group of bioactive lipids that might serve as secondary modulators, which when mobilized coincident with or shortly after first-line immune modulators, increase or decrease many immune functions.

Most immune cells express these bioactive lipids, together with their set of receptors and of enzymes regulating their synthesis and degradation.

In this review, a synopsis of the manifold immunomodulatory effects of endocannabinoids and their signaling in the different cell populations of innate and adaptive immunity is appointed, with a particular distinction between mice and human immune system compartments.”

http://www.ncbi.nlm.nih.gov/pubmed/25585882

Palmitoyl Serine: An Endogenous Neuroprotective Endocannabinoid-Like Entity After Traumatic Brain Injury.

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“The endocannabinoid (eCB) system helps recovery following traumatic brain injury (TBI).

Treatment with 2-arachidonoylglycerol (2-AG), a cerebral eCB ligand, was found to ameliorate the secondary damage.

Interestingly, the fatty acid amino acid amide (FAAA) N-arachidonoyl-L-serine (AraS) exerts similar eCB dependent neuroprotective. The present study aimed to investigate the effects of the FAAA palmitoyl-serine (PalmS) following TBI.

We suggest that the neuroprotective action of PalmS is mediated by indirect activation of the eCB receptors following TBI. One such mechanism may involve receptor palmitoylation which has been reported to result in structural stabilization of the receptors and to an increase in their activity. Further research is required in order to establish this assumption.”

http://www.ncbi.nlm.nih.gov/pubmed/25721934

http://www.thctotalhealthcare.com/category/brain-trauma/

Chronic administration with AM251 improves albuminuria and renal tubular structure in obese rats.

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“Modulation of the endocannabinoid system as an anti-obesity therapeutic is well established, however the direct effects of CB1 antagonism on renal function and structure in a model of diet-induced obesity (DIO) are unknown. The aim of this study was to characterise the renal effects of the CB1 antagonist AM251 in a model of DIO.

Antagonism of CB1 with AM251 significantly reduced weight gain, systolic blood pressure, plasma leptin, and reduced albuminuria and plasma creatinine levels in obese rats.

Importantly, there was a significant reduction in tubular cross-section diameter in the obese rats treated with AM251. An improvement in albuminuria was likely due to the reduction in tubular size, reduced leptinemia and maintenance of megalin expression levels. In obese rats, AM251 did not alter diastolic blood pressure, sodium excretion, creatinine clearance or expression of the fibrotic proteins VEGF, TGFb1 and collagen IV in the kidney.

This study demonstrates that treatment with CB1 antagonist AM251 improves renal outcomes in obese rats.”

http://www.ncbi.nlm.nih.gov/pubmed/25804605

“Alexandros Makriyannis is a professor in the Department of Medicinal Chemistry at Northeastern University, where his research group has synthesized many new compounds with cannabinoid activity… AM-251 — an inverse agonist at the CB1 cannabinoid receptor that is structurally related to SR141716A (rimonabant), but has a higher binding affinity with a Ki value of 7.5nM.”  http://en.wikipedia.org/wiki/List_of_AM_cannabinoids