Category Archives: Alzheimer’s Disease (AD)

Cannabinoid pharmacology/therapeutics in chronic degenerative disorders affecting the central nervous system.

Posted on by
Reply

 Biochemical Pharmacology “The endocannabinoid system (ECS) exerts a modulatory effect of important functions such as neurotransmission, glial activation, oxidative stress, or protein homeostasis.

Dysregulation of these cellular processes is a common neuropathological hallmark in aging and in neurodegenerative diseases of the central nervous system (CNS). The broad spectrum of actions of cannabinoids allows targeting different aspects of these multifactorial diseases.

In this review, we examine the therapeutic potential of the ECS for the treatment of chronic neurodegenerative diseases of the CNS focusing on Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, and amyotrophic lateral sclerosis.

First, we describe the localization of the molecular components of the ECS and how they are altered under neurodegenerative conditions, either contributing to or protecting cells from degeneration.

Second, we address recent advances in the modulation of the ECS using experimental models through different strategies including the direct targeting of cannabinoid receptors with agonists or antagonists, increasing the endocannabinoid tone by the inhibition of endocannabinoid hydrolysis, and activation of cannabinoid receptor-independent effects.

Preclinical evidence indicates that cannabinoid pharmacology is complex but supports the therapeutic potential of targeting the ECS.

Third, we review the clinical evidence and discuss the future perspectives on how to bridge human and animal studies to develop cannabinoid-based therapies for each neurodegenerative disorder.

Finally, we summarize the most relevant opportunities of cannabinoid pharmacology related to each disease and the multiple unexplored pathways in cannabinoid pharmacology that could be useful for the treatment of neurodegenerative diseases.”

https://www.ncbi.nlm.nih.gov/pubmed/30121249

https://www.sciencedirect.com/science/article/abs/pii/S000629521830337X

Genetic deletion of CB1 cannabinoid receptors exacerbates the Alzheimer-like symptoms in a transgenic animal model.

Posted on by
Reply

Biochemical Pharmacology

“Activating CB1 cannabinoid receptor has been demonstrated to produce certain therapeutic effects in animal models of Alzheimer’s disease (AD).

In this study, we evaluated the specific contribution of CB1 receptor to the progression of AD-like pathology in double transgenic APP/PS1 mice.

In summary, our results suggest a crucial role for CB1 receptor in the progression of AD-related pathological events.”

 https://www.ncbi.nlm.nih.gov/pubmed/30096288
https://www.sciencedirect.com/science/article/abs/pii/S0006295218303277

Therapeutic applications of cannabinoids.

Posted on by
Reply

Chemico-Biological Interactions

“The psychoactive properties of cannabinoids are well known and there has been a continuous controversy regarding the usage of these compounds for therapeutic purposes all over the world. Their use for medical and research purposes are restricted in various countries. However, their utility as medications should not be overshadowed by their negative physiological activities.

This review article is focused on the therapeutic potential and applications of phytocannabinoids and endocannabinoids. It highlights their mode of action, overall effects on physiology, various in vitro and in vivo studies that have been done so far and the extent to which these compounds can be useful in different disease conditions such as cancer, Alzheimer’s disease, multiple sclerosis, pain, inflammation, glaucoma and many others.

Thus, this work is an attempt to make the readers understand the positive implications of these compounds and indicates the significant developments that can occur upon utilizing cannabinoids as therapeutic agents.”  https://www.ncbi.nlm.nih.gov/pubmed/30040916

“Cannabinoids can be used as therapeutic agents.”   https://www.sciencedirect.com/science/article/pii/S0009279718307373?via%3Dihub

Modulation of the Cannabinoid System: A New Perspective for the Treatment of the Alzheimer’s Disease.

Posted on by
Reply

“The pathogenesis of Alzheimer’s disease (AD) is somewhat complex and has yet to be fully understood. As the effectiveness of the therapy currently available for AD has proved to be limited, the need for new drugs has become increasingly urgent.

The modulation of the endogenous cannabinoid system (ECBS) is one of the potential therapeutic approaches that is attracting a growing amount of interest. The ECBS consists of endogenous compounds and receptors. The receptors CB1 and CB2 have already been well characterized: CB1 receptors, which are abundant in the brain, particularly in the hippocampus, basal ganglia and cerebellum, regulate memory function and cognition.

It has been suggested that the activation of CB1 receptors reduces intracellular Ca concentrations, inhibits glutamate release and enhances neurotrophin expression and neurogenesis. CB2 receptors are expressed, though to a lesser extent, in the central nervous system, particularly in microglia and in immune system cells involved in the release of cytokines. CB2 receptors have been shown to be upregulated in neuritic plaque-associated migroglia in the hippocampus and entorhinal cortex of patients, which suggests that these receptors play a role in the inflammatory pathology of AD.

The role of the ECBS in AD is supported by cellular and animal models. By contrast, few clinical studies designed to investigate therapies aimed at reducing behaviour disturbances, especially night-time agitation, eating behaviour and aggressiveness, have yielded positive results. In this review, we will describe how the manipulation of the ECBS offers a potential approach to the treatment of AD.”

 https://www.ncbi.nlm.nih.gov/pubmed/29962346
http://www.eurekaselect.com/163401/article

GPR3, GPR6, and GPR12 as novel molecular targets: their biological functions and interaction with cannabidiol.

Posted on by
Reply

Image result for APS journal

“The G protein-coupled receptors 3, 6, and 12 (GPR3, GPR6, and GPR12) comprise a family of closely related orphan receptors with no confirmed endogenous ligands. These receptors are constitutively active and capable of signaling through G protein-mediated and non-G protein-mediated mechanisms. These orphan receptors have previously been reported to play important roles in many normal physiological functions and to be involved in a variety of pathological conditions.

Although they are orphans, GPR3, GPR6, and GPR12 are phylogenetically most closely related to the cannabinoid receptors. Using β-arrestin2 recruitment and cAMP accumulation assays, we recently found that the nonpsychoactive phytocannabinoid cannabidiol (CBD) is an inverse agonist for GPR3, GPR6, and GPR12.

This discovery highlights these orphan receptors as potential new molecular targets for CBD, provides novel mechanisms of action, and suggests new therapeutic uses of CBD for illnesses such as Alzheimer’s disease, Parkinson’s disease, cancer, and infertility. Furthermore, identification of CBD as a new inverse agonist for GPR3, GPR6, and GPR12 provides the initial chemical scaffolds upon which potent and efficacious agents acting on these receptors can be developed, with the goal of developing chemical tools for studying these orphan receptors and ultimately new therapeutic agents.”

https://www.ncbi.nlm.nih.gov/pubmed/29941868

https://www.nature.com/articles/s41401-018-0031-9

Endocannabinoid and Muscarinic Signaling Crosstalk in the 3xTg-AD Mouse Model of Alzheimer’s Disease.

Posted on by
Reply

 Image result for ios press

“The endocannabinoid system, which modulates emotional learning and memory through CB1 receptors, has been found to be deregulated in Alzheimer’s disease (AD).

AD is characterized by a progressive decline in memory associated with selective impairment of cholinergic neurotransmission. The functional interplay of endocannabinoid and muscarinic signaling was analyzed in seven-month-old 3xTg-AD mice following the evaluation of learning and memory of an aversive stimulus.

The subchronic (seven days) stimulation of the endocannabinoid system following repeated WIN55,212-2 (1 mg/kg) or JZL184 (8 mg/kg) administration induced a CB1 receptor downregulation and CB1-mediated signaling desensitization, normalizing acquisition latencies to control levels. However, the observed modulation of cholinergic neurotransmission in limbic areas did not modify learning and memory outcomes.

A CB1 receptor-mediated decrease of GABAergic tone in the basolateral amygdala may be controlling the limbic component of learning and memory in 3xTg-AD mice. CB1 receptor desensitization may be a plausible strategy to improve behavior alterations associated with genetic risk factors for developing AD.”

https://www.ncbi.nlm.nih.gov/pubmed/29865071

https://content.iospress.com/articles/journal-of-alzheimers-disease/jad180137

Cannabinoid Receptor 2-Deficiency Ameliorates Disease Symptoms in a Mouse Model with Alzheimer’s Disease-Like Pathology.

Posted on by
Reply

 Image result for ios press

“It is widely accepted that the endocannabinoid system (ECS) is a modulator of neuroinflammation associated with neurodegenerative disorders, including Alzheimer’s disease (AD).

Thus, expression of the cannabinoid receptor 2 (CB2) is induced in plaque-associated microglia and astrocytes in brain tissues from AD patients and in genetic mouse models expressing pathogenic variants of the amyloid precursor protein (APP).

However, the exact mechanism of CB2 signaling in this mouse model remains elusive, because the genetic deletion of CB2 and the pharmacological activation of CB2 both reduced neuroinflammation.

Here, we demonstrate that CB2 deletion also improved cognitive and learning deficits in APP/PS1*CB2-/- mice. This was accompanied by reduced neuronal loss and decreased plaque levels and coincided with increased expression of Aβ degrading enzymes. Interestingly, plaque-associated microglia in APP/PS1*CB2-/- mice showed a less activated morphology, while plaques were smaller and more condensed than in APP/PS1 mice.

Taken together, these results indicate a beneficial effect of CB2-deficiency in APP transgenic mice. CB2 appears to be part of a protective system that may be detrimental when engaged continuously.”

https://www.ncbi.nlm.nih.gov/pubmed/29865078

https://content.iospress.com/articles/journal-of-alzheimers-disease/jad180230

The biomedical challenge of neurodegenerative disorders: an opportunity for cannabinoid-based therapies to improve on the poor current therapeutic outcomes.

Posted on by
Reply

British Journal of Pharmacology banner

“At the beginning of the 21st century, the therapeutic management of neurodegenerative disorders remains a major biomedical challenge, particularly given the worldwide aging of the population over the past 50 years that is expected to continue in the forthcoming years.

This review will focus on the promise of cannabinoid based therapies to address this challenge.

Such promise is based on the broad neuroprotective profile of cannabinoids, which may cooperate to combat excitotoxicity, oxidative stress, glia-driven inflammation and protein aggregation.

Such effects may be produced by the activity of cannabinoids through their canonical targets (e.g. cannabinoid receptors, endocannabinoid enzymes) but also, via non-canonical elements and activities in distinct cell types critical for cell survival or neuronal replacement (e.g. neurons, glia, neural precursor cells).

Ultimately, the therapeutic events driven by endocannabinoid signalling reflect the activity of an endogenous system that regulates the preservation, rescue, repair and replacement of neurons and glia.”

https://www.ncbi.nlm.nih.gov/pubmed/29856067

https://bpspubs.onlinelibrary.wiley.com/doi/abs/10.1111/bph.14382

Cannabinoid CB2 receptors in the mouse brain: relevance for Alzheimer’s disease.

Posted on by
Reply

Image result for BMC journal of neuroinflammation

“Because of their low levels of expression and the inadequacy of current research tools, CB2 cannabinoid receptors (CB2R) have been difficult to study, particularly in the brain. This receptor is especially relevant in the context of neuroinflammation, so novel tools are needed to unveil its pathophysiological role(s).

METHODS:

We have generated a transgenic mouse model in which the expression of enhanced green fluorescent protein (EGFP) is under the control of the cnr2 gene promoter through the insertion of an Internal Ribosomal Entry Site followed by the EGFP coding region immediately 3′ of the cnr2 gene and crossed these mice with mice expressing five familial Alzheimer’s disease (AD) mutations (5xFAD).

RESULTS:

Expression of EGFP in control mice was below the level of detection in all regions of the central nervous system (CNS) that we examined. CB2R-dependent-EGFP expression was detected in the CNS of 3-month-old AD mice in areas of intense inflammation and amyloid deposition; expression was coincident with the appearance of plaques in the cortex, hippocampus, brain stem, and thalamus. The expression of EGFP increased as a function of plaque formation and subsequent microgliosis and was restricted to microglial cells located in close proximity to neuritic plaques. AD mice with CB2R deletion exhibited decreased neuritic plaques with no changes in IL1β expression.

CONCLUSIONS:

Using a novel reporter mouse line, we found no evidence for CB2R expression in the healthy CNS but clear up-regulation in the context of amyloid-triggered neuroinflammation. Data from CB2R null mice indicate that they play a complex role in the response to plaque formation.”

 https://www.ncbi.nlm.nih.gov/pubmed/29793509
https://jneuroinflammation.biomedcentral.com/articles/10.1186/s12974-018-1174-9