Microglia activation states and cannabinoid system: Therapeutic implications.

“Microglial cells are recognized as the brain’s intrinsic immune cells, mediating actions that range from the protection against harmful conditions that modify CNS homeostasis, to the control of proliferation and differentiation of neurons and their synaptic pruning. To perform these functions, microglia adopts different activation states, the so-called phenotypes that depending on the local environment involve them in neuroinflammation, tissue repair and even the resolution of the inflammatory process.

There is accumulating evidence indicating that cannabinoids (CBs) might serve as a promising tool to modify the outcome of inflammation, especially by influencing microglial activity.

Microglia has a functional endocannabinoid (eCB) signaling system, composed of cannabinoid receptors and the complete machinery for the synthesis and degradation of eCBs.

The expression of cannabinoid receptors – mainly CB2 – and the production of eCBs have been related to the activation profile of these cells and therefore, the microglial phenotype, emerging as one of the mechanisms by which microglia becomes alternatively activated.

Here, we will discuss recent studies that provide new insights into the role of CBs and their endogenous counterparts in defining the profile of microglia activation.

These actions make CBs a promising therapeutic tool to avoid the detrimental effects of inflammation and possibly paving the way to target microglia in order to generate a reparative milieu in neurodegenerative diseases.”

http://www.ncbi.nlm.nih.gov/pubmed/27373505

The bright side of psychoactive substances: cannabinoid-based drugs in motor diseases.

“Psychoactive substances are associated with the idea of drugs with high addictive liability, affecting mental states, cognition, emotion and motor behavior. However these substances can modify synaptic transmission and help to disclose some mechanisms underlying alterations in brain processing and pathophysiology of motor disease. Hence, the “bright side” of cannabinoid-based drugs must be thoroughly examined to be identified within the latter framework.

We will analyze the preclinical and clinical evidence of cannabinoid-based drugs, discussing their therapeutic value in basal ganglia motor disorders such as Parkinson’s disease and Huntington disease.

Expert commentary: despite the knowledge acquired in the last years, the therapeutic potential of cannabinoid-based drugs should be further tested by novel routes of investigation. This should be focused on the role of cannabinoid signaling system in mitochondrial function as well as on the physical and functional interaction with other key receptorial targets belonging to this network.”

http://www.ncbi.nlm.nih.gov/pubmed/27373318

Cannabinoid receptors in the kidney.

“The endocannabinoid system modulates cell signaling targets that are essential for energy homeostasis. Endocannabinoids bind to G protein-coupled receptors in the central nervous system and periphery, including the kidney. Modulation of cannabinoid receptor 1 (CB1) and CB2 activity in the kidney in diabetes and obesity has been identified as potential therapeutic target to reduce albuminuria and renal fibrosis.

CB1 and CB2 have been reported to play key roles in renal function and dysfunction. Recent studies have determined that antagonism of CB1 and agonism of CB2 in diabetic nephropathy and obesity associated kidney disease can reduce albuminuria, potentially by acting on both the glomeruli and tubules. Emerging studies have also identified a role for CB1 in renal diseases associated with fibrosis, with CB1 upregulated in multiple models of human nephropathies.

Emerging studies using isolated cells, rodent models, and human studies have identified a critical role for the endocannabinoid system in renal function and disease. Thus, therapeutics that modulate the activity of CB1 and CB2 in renal disease could become clinically relevant.”

http://www.ncbi.nlm.nih.gov/pubmed/27367912

 

Endocannabionoid System in Neurological Disorders.

“Several studies support the evidence that the endocannabinoid system and cannabimimetic drugs might have therapeutic potential in numerous pathologies. These pathologies range from neurological disorders, atherosclerosis, stroke, cancer to obesity/metabolic syndrome and others.

In this paper we review the endocannabinoid system signaling and its alteration in neurodegenerative disorders like multiple sclerosis, Alzheimer’s disease, Parkinson’s disease and Huntington’s disease and discuss the main findings about the use of cannabinoids in the therapy of these pathologies.

Despite different etiologies, neurodegenerative disorders exhibit similar mechanisms like neuro-inflammation, excitotoxicity, deregulation of intercellular communication, mitochondrial dysfunction and disruption of brain tissue homeostasis.

Current treatments ameliorate the symptoms but are not curative.

Interfering with the endocannabinoid signaling might be a valid therapeutic option in neuro-degeneration.

To this aim, pharmacological intervention to modulate the endocannabinoid system and the use of natural and synthetic cannabimimetic drugs have been assessed. CB1 and CB2 receptor signaling contributes to the control of Ca2+ homeostasis, trophic support, mitochondrial activity, and inflammatory conditions.

Several studies and patents suggest that the endocannabinoid system has neuro-protective properties and might be a target in neurodegenerative diseases.”

http://www.ncbi.nlm.nih.gov/pubmed/27364363

Marijuana fights Alzheimer’s disease, Salk Institute scientists discover

Cannabinoids remove plaque-forming Alzheimer's proteins from brain cells

“Salk Institute scientists have discovered that a main compound found in marijuana can fight a toxic protein associated with Alzheimer’s disease. According to the scientists, at this time, there are no drugs that significantly inhibit cell death associated with Alzheimer’s disease (AD), Parkinson’s or Huntington’s diseases. However, the most recent data about Alzheimer’s and marijuana suggests that there is a therapeutic potential of cannabinoids (the chemical compounds secreted by cannabis flowers) for the treatment of AD. Cannabinoids are able to remove plaque-forming Alzheimer’s proteins from brain cells, reports the Medical Express on June 29.”  http://www.examiner.com/article/marijuana-fights-alzheimer-s-disease-salk-institute-scientists-discover

“Cannabinoids remove plaque-forming Alzheimer’s proteins from brain cells”  http://medicalxpress.com/news/2016-06-cannabinoids-plaque-forming-alzheimer-proteins-brain.html

“Cannabinoids remove toxic proteins associated with Alzheimer’s disease from the brain” http://www.irishexaminer.com/examviral/science-world/cannabinoids-remove-toxic-proteins-associated-with-alzheimers-disease-from-the-brain-407788.html

“Marijuana Compound Helps Remove Alzheimer’s Disease Protein From Brain” -brain.” http://www.scienceworldreport.com/articles/42990/20160630/marijuana-compound-helps-remove-alzheimers-disease-protein-from-brain.htm

“Marijuana compound removes toxic Alzheimer’s protein from the brain”  http://www.sciencealert.com/marijuana-compound-removes-toxic-alzheimer-s-protein-from-the-brain

“Cannabinoids remove plaque-forming Alzheimer’s proteins from brain cells”  https://www.sciencedaily.com/releases/2016/06/160629095609.htm

“Cannabinoids Remove Plaque-forming Alzheimer’s Proteins from Brain Cells”  https://www.laboratoryequipment.com/news/2016/06/cannabinoids-remove-plaque-forming-alzheimers-proteins-brain-cells

“MARIJUANA COMPOUND REMOVES ALZHEIMER’S PLAQUE FROM BRAIN CELLS, STUDY FINDS” http://www.popsci.com/marijuana-compound-removes-alzheimers-plaque-from-brain-cells-study

“Cannabinoids remove plaque-forming Alzheimer’s proteins from brain cells. Preliminary lab studies at the Salk Institute find THC reduces beta amyloid proteins in human neurons.” http://www.salk.edu/news-release/cannabinoids-remove-plaque-forming-alzheimers-proteins-from-brain-cells/

 

The multiple waves of cannabinoid 1 receptor signaling.

“The cannabinoid 1 receptor (CB1R) is one of the most abundant G protein-coupled receptor (GPCR) in the CNS with key roles during neurotransmitter release and synaptic plasticity. Upon ligand activation, CB1Rs may signal in three different spatiotemporal waves.

The first wave is transient (<10 minutes) and is initiated by heterotrimeric G proteins followed by a second wave (>10 minutes) mediated by beta-arrestins. A final third wave occurs at intracellular compartments and could be elicited by G proteins or beta-arrestins.

This functional complexity presents multiple challenges, from the correct classification of receptor ligands to the identification of the signaling pathways regulated by each wave and their underlying molecular mechanisms and physiological impact.

Simultaneously, it provides new opportunities to harness the therapeutic potential of the cannabinoid system.

Over the last several years, we have significantly expanded our understanding of the mechanisms and pathways downstream from CB1R. The identification of mutations in the receptor that can bias signaling to specific pathways and the use of siRNA technology in combination with toxins have been key tools to identify which signaling cascades are controlled by G proteins or beta-arrestins.

Here, we review our current knowledge of the multiple waves of CB1R signaling with particular emphasis on the mechanisms and cascades mediated by beta-arrestins downstream from the CB1R.”

http://www.ncbi.nlm.nih.gov/pubmed/27338082

Activation of the orphan receptor GPR55 by lysophosphatidylinositol promotes metastasis in triple-negative breast cancer.

Image result for Oncotarget.“The orphan G protein-coupled receptor GPR55 has been directly or indirectly related to basic alterations that drive malignant growth: uncontrolled cancer cell proliferation, sustained angiogenesis, and cancer cell adhesion and migration. However, little is known about the involvement of this receptor in metastasis.

Here, we show that elevated GPR55 expression in human tumors is associated with the aggressive basal/triple-negative breast cancer population, higher probability to develop metastases, and therefore poor patient prognosis. Activation of GPR55 by its proposed endogenous ligand lysophosphatidylinositol confers pro-invasive features on breast cancer cells both in vitro and in vivo. Specifically, this effect is elicited by coupling to Gq/11 heterotrimeric proteins and the subsequent activation, through ERK, of the transcription factor ETV4/PEA3.

Together, these data show that GPR55 promotes breast cancer metastasis, and supports the notion that this orphan receptor may constitute a new therapeutic target and potential biomarker in the highly aggressive triple-negative subtype.”

http://www.ncbi.nlm.nih.gov/pubmed/27340777

Cannabimimetic Drugs: Recent Patents in Central Nervous System Disorders.

“Agents acting via cannabinoid receptors have been widely developed; starting from the chemical structure of phytocannabinoids isolated from cannabis sativa plant, specific and selective compounds of these receptors have been produced ranging from partial to full agonists and /or antagonists endowed with different potency.

The enhanced interest on developing such classes of drugs is due to the beneficial properties widely reported by both anecdotal reports and scientific studies describing the potential medicinal use of cannabinoids and their derivatives in numerous pathological conditions in both in vitro and in vivo models.

The use of these drugs has been found to be of benefit in a wide number of neurological and neuropsychiatric disorders, and in many other diseases ranging from cancer, atherosclerosis, stroke, hypertension, inflammatory related disorders, and autoimmune diseases, just to mention some.

In particular, being the cannabinoid CB1 receptor a central receptor expressed by neurons of the central nervous system, the attention for the treatment of neurological diseases has been mainly focused on compounds acting via this receptor, however some of these compounds has been showed to act by alternative pathways in some cases unrelated to CB1 receptors.

Nonetheless, endocannabinoids are potent regulators of the synaptic function in the central nervous system and their levels are modulated in neurological diseases.

In this study, we focused on endocannabinoid mechanism of action in neuronal signaling and on cannabimimetic drug potential application in neurological disorders.

Finally, novel patents on cannabis-based drugs with applicability in central nervous system disorders are highlighted, to suggest future potential therapeutic utility of derivatives of this ancient plant.”

http://www.ncbi.nlm.nih.gov/pubmed/27334611

Harnessing the Endocannabinoid 2-Arachidonoylglycerol to Lower Intraocular Pressure in a Murine Model.

“Cannabinoids, such as Δ9-THC, act through an endogenous signaling system in the vertebrate eye that reduces IOP via CB1 receptors.

Endogenous cannabinoid (eCB) ligand, 2-arachidonoyl glycerol (2-AG), likewise activates CB1 and is metabolized by monoacylglycerol lipase (MAGL). We investigated ocular 2-AG and its regulation by MAGL and the therapeutic potential of harnessing eCBs to lower IOP.

Our data confirm a central role for MAGL in metabolism of ocular 2-AG and related lipid species, and that endogenous 2-AG can be harnessed to reduce IOP. The MAGL blocker KML29 has promise as a therapeutic agent, while JZL184 may have difficulty crossing the cornea.

These data, combined with the relative specificity of MAGL for ocular monoacylglycerols and the lack of desensitization in MAGL-/- mice, suggest that the development of an optimized MAGL blocker offers therapeutic potential for treatment of elevated IOP.”

http://www.ncbi.nlm.nih.gov/pubmed/27333182

FABP1 in wonderland.

“Cannabinoid receptors hold a core position in the brain and control memory, cognition, movement, and pain sensitivity. sn-2 arachidonoylglycerol (2-AG) activates neuronal cannabinoid receptors as a full agonist. The brain may rely on circulating arachidonic acid to synthesize endogenous cannabinoids. This Editorial highlights a study by Martin and coworkers in the current issue of the Journal of Neurochemistry in which the authors describe, for the first time, that liver acts as a pool of arachidonic acid that under certain conditions feeds the brain to produce endocannabinoids. Therapeutics affecting liver FABP1 levels should take into account that FABP1 represents a fatty acid reservoirs for the brain. Read the highlighted article “FABP-1 gene ablation impacts brain endocannabinoid system in male mice”” http://www.ncbi.nlm.nih.gov/pubmed/27329821