“Endocannabinoids exert their effect on the regulation of energy homeostasis via activation of specific receptors. They control food intake, secretion of insulin, lipids and glucose metabolism, lipid storage. Long chain fatty acids are the main myocardial energy substrate. However, the heart exerts enormous metabolic flexibility emphasized by its ability to utilzation not only fatty acids, but also glucose, lactate and ketone bodies. Endocannabinoids can directly act on the cardiomyocytes through the CB1 and CB2 receptors present in cardiomyocytes. It appears that direct activation of CB1 receptors promotes increased lipogenesis, pericardial steatosis and bioelectrical dysfunction of the heart. In contrast, stimulation of CB2 receptors exhibits cardioprotective properties, helping to maintain appropriate amount of ATP in cardiomyocytes. Furthermore, the effects of endocannabinoids at both the central nervous system and peripheral tissues, such as liver, pancreas, or adipose tissue, resulting indirectly in plasma availability of energy substrates and affects myocardial metabolism. To date, there is little evidence that describes effects of activation of the endocannabinoid system in the cardiovascular system under physiological conditions. In the present paper the impact of metabolic diseases, i. e. obesity and diabetes, as well as the cardiovascular diseases – hypertension, myocardial ischemia and myocardial infarction on the deregulation of the endocannabinoid system and its effect on the metabolism are described.”
Tag Archives: cannabinoid receptors
Cannabinoids and Neuro-Inflammation: Regulation of Brain Immune Response.
“Cannabinoid receptors are involved in neurophatogenic mechanisms of inflammatory disorders of the central nervous system and their expression can be modulated during the disease.
Brain inflammatory processes are characterized by infiltration of numerous types of cells, peripheral immune cells, brain resident immune cells, the microglial cells and numerous other neuronal cells. The disruption of the blood brain barrier favours cell infiltration in the central nervous system with consequent neuronal damage, common event in many neuro-inflammatory diseases.
In this review we evidence the role of cannabinoid receptor, their expression at peripheral and central levels in order to better understand their implication in neuro-inflammation.
Cannabinoids affect brain adaptive and immune response, have regulatory action on inflammatory mediators and can exert a role in blood brain barrier damage prevention.
Furthermore, in numerous neurodegenerative diseases with inflammatory component the beneficial effects of cannabinoids have been widely reported, so current knowledge of cannabinoid involvement in these central nervous system disorders are also reviewed.”
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.”
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.”
Fabp-1 gene ablation impacts brain endocannabinoid system in male mice.
“Liver fatty acid binding protein (FABP1, L-FABP) has high affinity for and enhances uptake of arachidonic acid (ARA, C20:4, n-6) which, when esterified to phospholipids, is the requisite precursor for synthesis of endocannabinoids (EC) such as arachidonoylethanolamide (AEA) and 2-arachidonoylglycerol (2-AG). The brain derives most of its ARA from plasma, taking up ARA and transporting it intracellularly via cytosolic fatty acid binding proteins (FABPs 3,5, and 7) localized within the brain. In contrast, the much more prevalent cytosolic FABP1 is not detectable in the brain but is instead highly expressed in the liver. Therefore, the possibility that FABP1 outside the central nervous system may regulate brain AEA and 2-AG was examined in wild-type (WT) and FABP1 null (LKO) male mice. LKO increased brain levels of AA-containing EC (AEA, 2-AG), correlating with increased free and total ARA in brain and serum. LKO also increased brain levels of non-ARA that contain potentiating endocannabinoids (EC*) such as OEA, PEA, 2-OG, and 2-PG. Concomitantly, LKO decreased serum total ARA-containing EC, but not non-ARA endocannabinoids. LKO did not elicit these changes in the brain EC and EC* due to compensatory upregulation of brain protein levels of enzymes in EC synthesis (NAPEPLD, DAGLα) or cytosolic EC chaperone proteins (FABPs 3, 5, 7, SCP-2, HSP70), or cannabinoid receptors (CB1, TRVP1). These data show for the first time that the non-CNS fatty acid binding protein FABP1 markedly affected brain levels of both ARA-containing endocannabinoids (AEA, 2-AG) as well as their non-ARA potentiating endocannabinoids.”
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
Activation of cannabinoid CB1 receptors suppresses the ROS-induced hypersensitivity of rat vagal lung C-fiber afferents.
“Reactive oxygen species (ROS), including H2O2, have been shown to induce hypersensitivity of vagal lung C-fibers (VLCFs) mainly through receptor potential ankyrin 1 (TRPA1) and P2X receptors.
Cannabinoids (CBs) exert antinociceptive effects by binding to specific CB receptors, designated CB1 and CB2 (type 2) for type 1 and type 2, respectively.
We investigated whether activation of CB receptors can suppress ROS-mediated VLCF hypersensitivity and, if so, what type(s) of CB receptors are involved.
:Our results suggest that activation of CB1 receptors may suppress the ROS-mediated VLCF hypersensitivity through a mechanism that is at least partly distinct from the function of TRPA1 and P2X receptors.”
Basolateral amygdala CB1 cannabinoid receptors are involved in cross state-dependent memory retrieval between morphine and ethanol.
“Ethanol and morphine are largely co-abused and affect memory formation.
The present study intended to investigate the involvement of cannabinoid CB1 receptors of the basolateral amygdala (BLA) in cross state-dependent memory retrieval between morphine and ethanol.
Taken together, it can be concluded that morphine and ethanol can induce state-dependent memory retrieval.
In addition, the BLA endocannabinoid system mediates via CB1 receptors the functional interaction of morphine and ethanol state-dependent memory retrieval which may depend on the rewarding effects of the drugs.”
The multiplicity of spinal AA-5-HT anti-nociceptive action in a rat model of neuropathic pain.
“There is considerable evidence to support the role of anandamide (AEA), an endogenous ligand of cannabinoid receptors, in neuropathic pain modulation. AEA also produces effects mediated by other biological targets, of which the transient receptor potential vanilloid type 1 (TRPV1) has been the most investigated. Both, inhibition of AEA breakdown by fatty acid amide hydrolase (FAAH) and blockage of TRPV1 have been shown to produce anti-nociceptive effects.
Recent research suggests the usefulness of dual-action compounds, which may afford greater anti-allodynic efficacy. Therefore, in the present study, we examined the effect of N-arachidonoyl-serotonin (AA-5-HT), a blocker of FAAH and TRPV1, in a rat model of neuropathic pain after intrathecal administration.
We found that treatment with AA-5-HT increased the pain threshold to mechanical and thermal stimuli, with highest effect at the dose of 500nM, which was most strongly attenuated by AM-630, CB2 antagonist, administration. The single action blockers PF-3845 (1000nM, for FAAH) and I-RTX (1nM, for TRPV1) showed lower efficacy than AA-5-HT. Moreover AA-5-HT (500nM) elevated AEA and palmitoylethanolamide (PEA) levels.
Among the possible targets of these mediators, only the mRNA levels of CB2, GPR18 and GPR55, which are believed to be novel cannabinoid receptors, were upregulated in the spinal cord and/or DRG of CCI rats. It was previously reported that AA-5-HT acts in CB1 and TRPV1-dependent manner after systemic administration, but here for the first time we show that AA-5-HT action at the spinal level involves CB2, with potential contributions from GRP18 and/or GPR55 receptors.”
The cannabinoid WIN 55,212-2 prevents neuroendocrine differentiation of LNCaP prostate cancer cells.
“Neuroendocrine (NE) differentiation represents a common feature of prostate cancer and is associated with accelerated disease progression and poor clinical outcome. Nowadays, there is no treatment for this aggressive form of prostate cancer.
The aim of this study was to determine the influence of the cannabinoid WIN 55,212-2 (WIN, a non-selective cannabinoid CB1 and CB2 receptor agonist) on the NE differentiation of prostate cancer cells.
Taken together, we demonstrate that PI3K/Akt/AMPK might be an important axis modulating NE differentiation of prostate cancer that is blocked by the cannabinoid WIN, pointing to a therapeutic potential of cannabinoids against NE prostate cancer.”