Endocannabinoid Modulation of Microglial Phenotypes in Neuropathology.

Image result for frontiers in neurology“Microglia, the resident immune cells of the central nervous system, mediate brain homeostasis by controlling neuronal proliferation/differentiation and synaptic activity. In response to external signals from neuropathological conditions, homeostatic (M0) microglia can adopt one of two activation states: the classical (M1) activation state, which secretes mediators of the proinflammatory response, and the alternative (M2) activation state, which presumably mediates the resolution of neuroinflammation and tissue repair/remodeling.

Since chronic inflammatory activation of microglia is correlated with several neurodegenerative diseases, functional modulation of microglial phenotypes has been considered as a potential therapeutic strategy.

The endocannabinoid (eCB) system, composed of cannabinoid receptors and ligands and their metabolic/biosynthetic enzymes, has been shown to activate anti-inflammatory signaling pathways that modulate immune cell functions. Growing evidence has demonstrated that endogenous, synthetic, and plant-derived eCB agonists possess therapeutic effects on several neuropathologies; however, the molecular mechanisms that mediate the anti-inflammatory effects have not yet been identified.

Over the last decade, it has been revealed that the eCB system modulates microglial activation and population. In this review, we thoroughly examine recent studies on microglial phenotype modulation by eCB in neuroinflammatory and neurodegenerative disease conditions.

We hypothesize that cannabinoid 2 receptor (CB2R) signaling shifts the balance of expression between neuroinflammatory (M1-type) genes, neuroprotective (M2-type) genes, and homeostatic (M0-type) genes toward the latter two gene expressions, by which microglia acquire therapeutic functionality.”

https://www.ncbi.nlm.nih.gov/pubmed/32117037

https://www.frontiersin.org/articles/10.3389/fneur.2020.00087/full

Cannabinoids and Hormone Receptor-Positive Breast Cancer Treatment.

cancers-logo “Breast cancer (BC) is the most common cancer in women worldwide. Approximately 70-80% of BCs express estrogen receptors (ER), which predict the response to endocrine therapy (ET), and are therefore hormone receptor-positive (HR+).

Endogenous cannabinoids together with cannabinoid receptor 1 and 2 (CB1, CB2) constitute the basis of the endocannabinoid system.

Interactions of cannabinoids with hypothalamic-pituitary-gonadal axis hormones are well documented, and two studies found a positive correlation between peak plasma endogenous cannabinoid anandamide with peak plasma 17β-estradiol, luteinizing hormone and follicle-stimulating hormone levels at ovulation in healthy premenopausal women. Do cannabinoids have an effect on HR+ BC? In this paper we review known and possible interactions between cannabinoids and specific HR+ BC treatments.

In preclinical studies, CB1 and CB2 agonists (i.e., anandamide, THC) have been shown to inhibit the proliferation of ER positive BC cell lines.

There is less evidence for antitumor cannabinoid action in HR+ BC in animal models and there are no clinical trials exploring the effects of cannabinoids on HR+ BC treatment outcomes. Two studies have shown that tamoxifen and several other selective estrogen receptor modulators (SERM) can act as inverse agonists on CB1 and CB2, an interaction with possible clinical consequences. In addition, cannabinoid action could interact with other commonly used endocrine and targeted therapies used in the treatment of HR+ BC.”

https://www.ncbi.nlm.nih.gov/pubmed/32106399

https://www.mdpi.com/2072-6694/12/3/525

Overview of cannabidiol (CBD) and its analogues: Structures, biological activities, and neuroprotective mechanisms in epilepsy and Alzheimer’s disease.

European Journal of Medicinal Chemistry“Herein, 11 general types of natural cannabinoids from Cannabis sativa as well as 50 (-)-CBD analogues with therapeutic potential were described. The underlying molecular mechanisms of CBD as a therapeutic candidate for epilepsy and neurodegenerative diseases were comprehensively clarified. CBD indirectly acts as an endogenous cannabinoid receptor agonist to exert its neuroprotective effects. CBD also promotes neuroprotection through different signal transduction pathways mediated indirectly by cannabinoid receptors. Furthermore, CBD prevents the glycogen synthase kinase 3β (GSK-3β) hyperphosphorylation caused by Aβ and may be developed as a new therapeutic candidate for Alzheimer’s disease.”

https://www.ncbi.nlm.nih.gov/pubmed/32109623

“For AD treatment, CBD can rescue the production of neurofibrillary tangles and inhibit neuronal apoptosis.”

https://www.sciencedirect.com/science/article/abs/pii/S0223523420301306?via%3DihubImage 1

Cannabinoid agonists possibly mediate interaction between cholinergic and cannabinoid systems in regulating intestinal inflammation.

Medical Hypotheses“Inflammatory Bowel Disease (IBD) is idiopathic, chronic and affects the gastrointestinal tract. It results from the association of genetic, environmental and immune deregulation, which culminates in the development and progression of the inflammatory process. In an attempt to reverse colonic inflammation, endogenous systems involved in intestinal physiology are studied and the cholinergic system is fundamental for this process. In addition, this system has anti-inflammatory action in experimental models of IBD. Another important endogenous system in regulating the exacerbated inflammatory response in the gut is mediated by endocannabinoids, which play an important role in restoring bowel functionality after the onset of the inflammatory process. There are several reports in the literature showing the interconnection between the cannabinoid and cholinergic systems in different tissues. Considering that the activation of the cholinergic system stimulates the production of cannabinoid agonists in the intestine, our hypothesis is that the interaction between the muscarinic system and the cannabinoid in the control of intestinal inflammation is mediated by endogenous cannabinoids, since they are stimulated by the activation of muscarinic receptors.”

https://www.ncbi.nlm.nih.gov/pubmed/32085982

https://www.sciencedirect.com/science/article/abs/pii/S030698771931429X?via%3Dihub

Cannabinoid-mediated Modulation of Oxidative Stress and Early Inflammatory Response after Hypoxia-Ischemia.

ijms-logo“In the process of neonatal encephalopathy, oxidative stress and neuroinflammation have a prominent role after perinatal asphyxia. With the exception of therapeutic hypothermia, no therapeutic interventions are available in the clinical setting to target either the oxidative stress or inflammation, despite the high prevalence of neurological sequelae of this devastating condition.

The endocannabinoid system (ECS), recently recognized as a widespread neuromodulatory system, plays an important role in the development of the central nervous system (CNS).

This study aims to evaluate the potential effect of the cannabinoid (CB) agonist WIN 55,212-2 (WIN) on reactive oxygen species (ROS) and early inflammatory cytokine production after hypoxia-ischemia (HI) in fetal lambs.

Hypoxic-ischemic animals were subjected to 60 min of HI by partial occlusion of the umbilical cord. A group of lambs received a single dose of 0.01 μg/kg WIN, whereas non-asphyctic animals served as controls. WIN reduced the widespread and notorious increase in inflammatory markers tumor necrosis factor (TNF)-α and interleukin (IL)-1β and IL-6 induced by HI, a modulatory effect not observed for oxidative stress.

Our study suggests that treatment with a low dose of WIN can alter the profile of pro-inflammatory cytokines 3 h after HI.”

https://www.ncbi.nlm.nih.gov/pubmed/32074976

https://www.mdpi.com/1422-0067/21/4/1283

“Cannabinoid as a neuroprotective strategy in perinatal hypoxic-ischemic injury.”   https://www.ncbi.nlm.nih.gov/pubmed/21788999

Cannabinoid receptor expression in non-small cell lung cancer. Effectiveness of tetrahydrocannabinol and cannabidiol inhibiting cell proliferation and epithelial-mesenchymal transition in vitro.

Image result for plos one “Patients with non-small cell lung cancer (NSCLC) develop resistance to antitumor agents by mechanisms that involve the epithelial-to-mesenchymal transition (EMT). This necessitates the development of new complementary drugs, e.g., cannabinoid receptors (CB1 and CB2) agonists including tetrahydrocannabinol (THC) and cannabidiol (CBD).

The combined use of THC and CBD confers greater benefits, as CBD enhances the effects of THC and reduces its psychotropic activity. We assessed the relationship between the expression levels of CB1 and CB2 to the clinical features of a cohort of patients with NSCLC, and the effect of THC and CBD (individually and in combination) on proliferation, EMT and migration in vitro in A549, H460 and H1792 lung cancer cell lines.

METHODS:

Expression levels of CB1, CB2, EGFR, CDH1, CDH2 and VIM were evaluated by quantitative reverse transcription-polymerase chain reaction. THC and CBD (10-100 μM), individually or in combination (1:1 ratio), were used for in vitro assays. Cell proliferation was determined by BrdU incorporation assay. Morphological changes in the cells were visualized by phase-contrast and fluorescence microscopy. Migration was studied by scratch recolonization induced by 20 ng/ml epidermal growth factor (EGF).

RESULTS:

The tumor samples were classified according to the level of expression of CB1, CB2, or both. Patients with high expression levels of CB1, CB2, and CB1/CB2 showed increased survival reaching significance for CB1 and CB1/CB2 (p = 0.035 and 0.025, respectively).

Both cannabinoid agonists inhibited the proliferation and expression of EGFR in lung cancer cells, and CBD potentiated the effect of THC. THC and CBD alone or in combination restored the epithelial phenotype, as evidenced by increased expression of CDH1 and reduced expression of CDH2 and VIM, as well as by fluorescence analysis of cellular cytoskeleton.

Finally, both cannabinoids reduced the in vitro migration of the three lung cancer cells lines used.

CONCLUSIONS:

The expression levels of CB1 and CB2 have a potential use as markers of survival in patients with NSCLC. THC and CBD inhibited the proliferation and expression of EGFR in the lung cancer cells studied. Finally, the THC/CBD combination restored the epithelial phenotype in vitro.”

https://www.ncbi.nlm.nih.gov/pubmed/32049991

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0228909

The Epigenetics of the Endocannabinoid System.

ijms-logo “The endocannabinoid system (ES) is a cell-signalling system widely distributed in biological tissues that includes endogenous ligands, receptors, and biosynthetic and hydrolysing machineries.

The impairment of the ES has been associated to several pathological conditions like behavioural, neurological, or metabolic disorders and infertility, suggesting that the modulation of this system may be critical for the maintenance of health status and disease treatment.

Lifestyle and environmental factors can exert long-term effects on gene expression without any change in the nucleotide sequence of DNA, affecting health maintenance and influencing both disease load and resistance. This potentially reversible “epigenetic” modulation of gene expression occurs through the chemical modification of DNA and histone protein tails or the specific production of regulatory non-coding RNA (ncRNA).

Recent findings demonstrate the epigenetic modulation of the ES in biological tissues; in the same way, endocannabinoids, phytocannabinoids, and cannabinoid receptor agonists and antagonists induce widespread or gene-specific epigenetic changes with the possibility of trans-generational epigenetic inheritance in the offspring explained by the transmission of deregulated epigenetic marks in the gametes.

Therefore, this review provides an update on the epigenetics of the ES, with particular attention on the emerging role in reproduction and fertility.”

https://www.ncbi.nlm.nih.gov/pubmed/32046164

https://www.mdpi.com/1422-0067/21/3/1113

Cannabinoid receptor 2 activation alleviates septic lung injury by promoting autophagy via inhibition of inflammatory mediator release.

Cellular Signalling“Septic lung injury is one of main causes of high mortality in severe patients. Inhibition of excessive inflammatory response is considered as an effective strategy for septic lung injury.

Previous studies have shown that cannabinoid receptor 2 (CB2), a G protein-coupled receptor, play an important role in immunosuppression.

Whether CB2 can be used as a therapeutic target for septic lung injury is unclear. The aim of this study is to explore the role of CB2 in sepsis and its potential mechanism.

These results suggest that CB2 serves as a protective target for septic lung injury by decreasing inflammatory factors, which is associated with the enhancement of autophagy.”

https://www.ncbi.nlm.nih.gov/pubmed/32027949

“Activation of cannabinoid receptor 2 can alleviate sepsis-induced lung injury.”

https://www.sciencedirect.com/science/article/abs/pii/S0898656820300334?via%3Dihub

The endocannabinoid receptors CB1 and CB2 affect the regenerative potential of adipose tissue MSCs.

Experimental Cell Research“Human adipose tissue includes large quantities of mesenchymal stromal cells (atMSCs), which represent an abundant cell source for therapeutic applications in the field of regenerative medicine.

Adipose tissue secrets various soluble factors including endocannabinoids, and atMSCs express the cannabinoid receptors CB1 and CB2. This indicates that adipose tissue possesses an endocannabinoid system (ECS). The ECS is also ascribed great significance for wound repair, e.g. by modulating inflammation. However, the exact effects of CB1/CB2 activation in human atMSCs have not been investigated, yet.

In the present study, we stimulated human atMSCs with increasing concentrations (1-30 μM) of the unspecific cannabinoid receptor ligand WIN55,212-2 and the specific CB2 agonist JWH-133, either alone or co-applied with the receptor antagonist Rimonabant (CB1) or AM 630 (CB2). We investigated the effects on metabolic activity, cell number, differentiation and cytokine release, which are important processes during tissue regeneration.

WIN decreased metabolic activity and cell number, which was reversed by Rimonabant. This suggests a CB1 dependent mechanism, whereas the number of atMSCs was increased after CB2 ligation. WIN and JWH increased the release of VEGF, TGF-β1 and HGF. Adipogenesis was enhanced by WIN, which could be reversed by blocking CB1. There was no effect on osteogenesis, and only WIN increased chondrogenic differentiation.

Our results indicate that definite activation of the cannabinoid receptors exerted different effects in atMSCs, which could be of specific value in cell-based therapy for wound regeneration.”

https://www.ncbi.nlm.nih.gov/pubmed/32006556

https://www.sciencedirect.com/science/article/abs/pii/S001448272030080X?via%3Dihub

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Organophosphate agent induces ADHD-like behaviors via inhibition of brain endocannabinoid-hydrolyzing enzyme(s) in adolescent male rats.

 Go to Volume 0, Issue ja“Anticholinergic organophosphate (OP) agents act on the diverse serine hydrolases, thereby revealing unexpected biological effects. Epidemiological studies indicate a relationship between OP exposure and development of attention-deficit/hyperactivity disorder (ADHD)-like symptoms, whereas no plausible mechanism for the OP-induced ADHD has been established.

The present investigation employs ethyl octylphosphonofluoridate (EOPF) as an OP-probe which is an extremely potent inhibitor of endocannabinoid (EC, anandamide and 2-arachidonoylglycerol)-hydrolyzing enzymes: i.e., fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL).

Ex vivo experiment shows that EOPF treatment decreases FAAH and MAGL activities and conversely increases EC levels in rat brain. Subsequently, EOPF (treated intraperitoneally once at 0, 1, 2, or 3 mg/kg) clearly induces ADHD-like behaviors (in elevated plus-maze test) in both Wistar and spontaneously hypertensive rats. The EOPF-induced behaviors are reduced by a concomitant administration of cannabinoid receptor inverse agonist SLV-319.

Accordingly, EC system is a feasible target for OP-caused ADHD-like behaviors in adolescent rats.”

https://www.ncbi.nlm.nih.gov/pubmed/31995978

https://pubs.acs.org/doi/abs/10.1021/acs.jafc.9b08195