Stimulation of brain glucose uptake by cannabinoid CB2 receptors and its therapeutic potential in Alzheimer’s disease

Cover image

“Brain disorders, including Alzheimer’s disease (AD), often involve specific early alterations in the metabolism of glucose in the brain.

The idea of alleviating symptoms of dementia by boosting cerebral energy metabolism has been toyed with for decades, yet safe pharmacological agents with well characterized mechanism of action are still lacking.

In this sense, we have investigated here the local cerebral glucoregulatory potential of the endocannabinoid system in rodents.

Cannabinoid CB2 receptors (CB2Rs) are emerging as important therapeutic targets in brain disorders that typically involve neurometabolic alterations.

Together, these results reveal a novel general glucoregulatory role for CB2Rs in the brain, raising therapeutic interest in CB2R agonists as nootropic agents.

In conclusion, the present results provide the first direct pharmacological evidence in vitroand in vivo of a role of CB2R in central glucoregulation.

Additionally, we found that glucoregulation by endogenous CB2R signalling is negatively affected by β-amyloidosis, thought to be the first pathological step in AD.

Therefore, it would be interesting to perform further studies to define how CB2R mediated glucoregulation contributes to the recently discovered therapeutic potential of CB2R agonists in animal models of AD”

http://www.sciencedirect.com/science/article/pii/S0028390816300879

Novel role of cannabinoid receptor 2 in inhibiting EGF/EGFR and IGF-I/IGF-IR pathways in breast cancer.

Image result for Oncotarget.“Breast cancer is the second leading cause of cancer deaths among women.

Cannabinoid receptor 2 (CNR2 or CB2) is an integral part of the endocannabinoid system.

Although CNR2 is highly expressed in the breast cancer tissues as well as breast cancer cell lines, its functional role in breast tumorigenesis is not well understood.

We observed that estrogen receptor-α negative (ERα-) breast cancer cells highly express epidermal growth factor receptor (EGFR) as well as insulin-like growth factor-I receptor (IGF-IR). We also observed IGF-IR upregulation in ERα+ breast cancer cells.

In addition, we found that higher CNR2 expression correlates with better recurrence free survival in ERα- and ERα+ breast cancer patients.

Our studies showed that CNR2 activation inhibited EGF and IGF-I-induced migration and invasion of ERα+ and ERα- breast cancer cells.

In conclusion, we show that CNR2 activation suppresses breast cancer through novel mechanisms by inhibiting EGF/EGFR and IGF-I/IGF-IR signaling axes.”

http://www.ncbi.nlm.nih.gov/pubmed/27213582

Synthetic cannabinoid receptor agonists and antagonists: implication in CNS disorders.

“Since the discovery of the cannabinoid receptors, numerous studies associate the endocannabinoid system with several physiological and pathological processes including cancer, appetite, fertility, memory, neuropathic and inflammatory pain, obesity, and neurodegenerative diseases.

Over the last two decades, several researches have been dedicated extensively on the cannabinoid receptors ligands since the direct activation of cannabinoid receptors results in several beneficial effects, in the brain and in the periphery.

During past years, cannabinoid CB1 and CB2 receptor ligands from plants or lab were rapidly developed and then various new structures were reported to be cannabinoids.

The CB1 and CB2 receptor ligands offer several therapeutic opportunities for several CNS-related diseases.

Based on the scientific literature, this review provides an overview of CB1 and CB2 receptor synthetic ligands obtained from drug research and in particular those synthesized for therapeutic purposes and potential clinical applications for central nervous system disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/27193072

Opposite roles of cannabinoid receptors 1 and 2 in hepatocarcinogenesis.

“The endocannabinoid system (ECS) exerts key roles in the development of liver fibrosis and fatty liver, two diseases that promote the development of hepatocellular carcinoma (HCC).

Although cannabinoids exert potent antitumour effects in vitro, the contribution of the ECS to carcinogenesis in vivo remains elusive.

CONCLUSIONS:

Similar to their role in fibrogenesis, CB1 and CB2 exert opposite effects on hepatocarcinogenesis and may provide novel therapeutic targets.”

http://www.ncbi.nlm.nih.gov/pubmed/27196571

Beyond Cannabis: Plants and the Endocannabinoid System.

“Plants have been the predominant source of medicines throughout the vast majority of human history, and remain so today outside of industrialized societies.

One of the most versatile in terms of its phytochemistry is cannabis, whose investigation has led directly to the discovery of a unique and widespread homeostatic physiological regulator, the endocannabinoid system.

While it had been the conventional wisdom until recently that only cannabis harbored active agents affecting the endocannabinoid system, in recent decades the search has widened and identified numerous additional plants whose components stimulate, antagonize, or modulate different aspects of this system.

These include common foodstuffs, herbs, spices, and more exotic ingredients: kava, chocolate, black pepper, and many others that are examined in this review.”

http://www.ncbi.nlm.nih.gov/pubmed/27179600

Potentiation of cannabinoid-induced cytotoxicity in Mantle Cell Lymphoma through modulation of ceramide metabolism

Logo of nihpa

“Ceramide accumulation is a widely described event in cancers after various treatments.

Ceramide levels are elevated in Mantle Cell Lymphoma (MCL) cells following treatment with cannabinoids.

In previous publications we and others observed that induction of ceramide accumulation by cannabinoids leads to apoptosis in MCL, glioma and pancreatic cancer.

Here, we investigated the pathways of ceramide accumulation in the MCL cell line Rec-1 using the stable endocannabinoid analogue R(+)-methanandamide (R-MA).

Our findings suggest that R-MA induces cell death in MCL via CB1-mediated upregulation of the de novo ceramide synthesis pathway.

This is the first study showing that the cytotoxic effect of a cannabinoid can be enhanced by modulation of ceramide metabolism.

The results suggest that interference with ceramide conversion may provide a tool to enhance the targeted cell death-promoting effects of cannabinoids in MCL and other malignant lymphomas overexpressing the CB1 receptor.

Cannabinoids have been suggested as a new non-toxic therapeutic option for cancer treatment.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3077284/

Cannabinoid receptors in mantle cell lymphoma

Logo of cc

“Mantle cell lymphoma (MCL) is a non-curable B cell lymphoma that in several independent studies have been shown to express higher levels of CB1 and CB2 than non-malignant B cells.

The endocannabinoid system is dysregulated in many types of cancer and is involved in the regulation of survival and proliferation of cancer cells and cancer stem cells, in cancer metabolism, as well as in pro-metastatic events such as angiogenesis, migration and invasion.

Previous in vitro studies of MCL cell lines and primary ex vivo isolated tumor cells have demonstrated that high concentrations of cannabinoid receptor ligands induced proliferation arrest and programmed cell death.

All together, the data suggest that perturbations in the endocannabinoid system participate in the regulation of multi-functional cell responses regarding proliferation, migration and cell death control.

Therefore, it can be concluded that further studies on pharmacological modulation of endocannabinoid accumulation and/or signaling offers an interesting option for novel anti-lymphoma therapy.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4353235/

Cannabinoid receptor-mediated apoptosis induced by R(+)-methanandamide and Win55,212-2 is associated with ceramide accumulation and p38 activation in mantle cell lymphoma.

“We have recently shown that cannabinoids induce growth inhibition and apoptosis in mantle cell lymphoma (MCL), a malignant B-cell lymphoma that expresses high levels of cannabinoid receptor types 1 and 2 (CB(1) and CB(2)).

In the current study, the role of each receptor and the signal transduction triggered by receptor ligation were investigated.

The present data suggest that targeting CB(1)/CB(2) may have therapeutic potential for the treatment of mantle cell lymphoma.”

http://www.ncbi.nlm.nih.gov/pubmed/16936228

Expression of cannabinoid receptors type 1 and type 2 in non-Hodgkin lymphoma: growth inhibition by receptor activation.

“Endogenous and synthetic cannabinoids exert antiproliferative and proapoptotic effects in various types of cancer and in mantle cell lymphoma (MCL).

In this study, we evaluated the expression of cannabinoid receptors type 1 and type 2 (CB1 and CB2) in non-Hodgkin lymphomas of B cell type.

Together, our results suggest that therapies using cannabinoid receptor ligands will have efficiency in reducing tumor burden in malignant lymphoma overexpressing CB1 and CB2.”

http://www.ncbi.nlm.nih.gov/pubmed/18546271

The role of cannabinoid receptors and the endocannabinoid system in mantle cell lymphoma and other non-Hodgkin lymphomas.

“The initiating oncogenic event in mantle cell lymphoma (MCL) is the translocation of cyclin D1, t(11;14)(q13;q32). However, other genetic aberrations are necessary for an overt lymphoma to arise. Like other B cell lymphomas, MCL at some points during the oncogenesis is dependent on interactions with other cells and factors in the microenvironment.

The G protein coupled receptors cannabinoid receptors 1 and 2 (CB1 and CB2) are expressed at low levels on non-malignant lymphocytes and at higher levels in MCL and other lymphoma subtypes.

In this review we give an overview of what is known on the role of the cannabinoid receptors and their ligands in lymphoma as compared to non-malignant T and B lymphocytes.

In MCL cannabinoids mainly reduce cell proliferation and induce cell death.

Importantly, our recent findings demonstrate that cannabinoids may induce either apoptosis or another type of programmed cell death, cytoplasmic vacuolation/paraptosis in MCL.”

http://www.ncbi.nlm.nih.gov/pubmed/22024769