“The first discovered member of the mammalian FABP family, liver fatty acid binding protein (FABP1, L-FABP), occurs at high cytosolic concentration in liver, intestine, and in the case of humans also in kidney. While the rat FABP1 is well studied, the extent these findings translate to human FABP1 is not clear-especially in view of recent studies showing that endocannabinoids and cannabinoids represent novel rat FABP1 ligands and FABP1 gene ablation impacts the hepatic endocannabinoid system, known to be involved in non-alcoholic fatty liver (NAFLD) development. Although not detectable in brain, FABP1 ablation nevertheless also impacts brain endocannabinoids. Despite overall tertiary structure similarity, human FABP1 differs significantly from rat FABP1 in secondary structure, much larger ligand binding cavity, and affinities/specificities for some ligands. Moreover, while both mouse and human FABP1 mediate ligand induction of peroxisome proliferator activated receptor-α (PPARα), they differ markedly in pattern of genes induced. This is critically important because a highly prevalent human single nucleotide polymorphism (SNP) (26-38 % minor allele frequency and 8.3 ± 1.9 % homozygous) results in a FABP1 T94A substitution that further accentuates these species differences. The human FABP1 T94A variant is associated with altered body mass index (BMI), clinical dyslipidemias (elevated plasma triglycerides and LDL cholesterol), atherothrombotic cerebral infarction, and non-alcoholic fatty liver disease (NAFLD). Resolving human FABP1 and the T94A variant’s impact on the endocannabinoid and cannabinoid system is an exciting challenge due to the importance of this system in hepatic lipid accumulation as well as behavior, pain, inflammation, and satiety.”
Tag Archives: Cannabinoids
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 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.”
Identification of Psychoactive Degradants of Cannabidiol in Simulated Gastric and Physiological Fluid
“The flowering plants of the genus Cannabis, which mainly comprises the sativa and indica species, have been recognized for medical treatment for millennia.
Although Cannabis contains nearly 500 compounds from 18 chemical classes, its physiological effects derive mainly from a family of naturally occurring compounds known as plant cannabinoids or phytocannabinoids. Of the more than 100 phytocannabinoids that have been identified in Cannabis, among the most important and widely studied are its main psychoactive constituent, Δ9-tetrahydrocannabinol (Δ9-THC), and the most important nonpsychoactive component, cannabidiol (CBD). Other biologically active phytocannabinoids that have been isolated in Cannabis include Δ8-THC, cannabinol, Δ9-tetrahydrocannabivarin, and cannabidivarin.
In recent research, orally administered cannabidiol (CBD) showed a relatively high incidence of somnolence in a pediatric population. Previous work has suggested that when CBD is exposed to an acidic environment, it degrades to Δ9-tetrahydrocannabinol (THC) and other psychoactive cannabinoids. To gain a better understanding of quantitative exposure, we completed an in vitro study by evaluating the formation of psychoactive cannabinoids when CBD is exposed to simulated gastric fluid (SGF).
SGF converts CBD into the psychoactive components Δ9-THC and Δ8-THC. The first-order kinetics observed in this study allowed estimated levels to be calculated and indicated that the acidic environment during normal gastrointestinal transit can expose orally CBD-treated patients to levels of THC and other psychoactive cannabinoids that may exceed the threshold for a physiological response. Delivery methods that decrease the potential for formation of psychoactive cannabinoids should be explored.
Despite persistent challenges with dosing and administration, CBD-based therapies have a good safety profile and a potential for efficacy in the treatment of a variety of medical conditions. The rapidly evolving sciences of drug delivery and cannabinoid pharmacology may soon lead to breakthroughs that will improve access to the benefits of this pharmacological class of agents. In addition, current technologies, such as transdermal-based therapy, may be able to eliminate the potential for psychotropic effects due to this acid-catalyzed cyclization by delivering CBD through the skin and into the neutral, nonreactive environment of the systemic circulation.”
Fatty acid amide hydrolase inhibition for the symptomatic relief of Parkinsońs disease.
“Elements of the endocannabinoid system are strongly expressed in the basal ganglia where they suffer profound rearrangements after dopamine depletion.
Modulation of the levels of the endocannabinoid 2-arachidonoyl glycerol by inhibiting monoacylglycerol lipase alters glial phenotypes and provides neuroprotection in a mouse model of Parkinsońs disease.
In this study, we assessed whether inhibiting fatty acid amide hydrolase could also provide beneficial effects on the time course of this disease.
Together, these results demonstrate an effect of fatty acid amide hydrolase inhibition on the motor symptoms of Parkinsońs disease in two distinct experimental models that is mediated by cannabinoid receptors.”
Cannabinoids reverse the effects of early stress on neurocognitive performance in adulthood.
“Early life stress (ES) significantly increases predisposition to psychopathologies. Cannabinoids may cause cognitive deficits and exacerbate the effects of ES.
Nevertheless, the endocannabinoid system has been suggested as a therapeutic target for the treatment of stress- and anxiety-related disorders.
Here we examined whether cannabinoids administered during “late adolescence” (extensive cannabis use in humans at the ages 18-25) could reverse the long-term adverse effects of ES on neurocognitive function in adulthood.
WIN administered during late adolescence prevented these stress-induced impairments and reduced anxiety levels.
There is a crucial role of the endocannabinoid system in the effects of early life stress on behavior at adulthood.”
Cannabinoids in the Brain: New Vistas on an Old Dilemma
“The use of cannabis as a therapeutic and recreational substance goes back to thousands of years throughout Asia, Middle East, Southern Africa, and South America.
The discovery of Δ-9-tetrahydrocannabinol (Δ9-THC) by Mechoulam and Gaoni in the midsixties as the major psychoactive constituent of cannabis sativa led to another important discovery, namely, its specific binding site that was isolated and cloned in 1990. This first cannabinoid receptor was coined CB1R and triggered a number of investigations on its expression, localization, and function within the body tissue including the brain, in various species. This was followed by the discovery in 1992 of the first endocannabinoid (eCB), anandamide, followed by another cannabinoid receptor CB2R and a second endocannabinoid called 2-arachidonoylglycerol (2-AG). Later on, some of the enzymes responsible for their synthesis (N-acyl phosphatidylethanolamine phospholipase D (NAPE-PLD); diacylglycerol lipase (DAGL)) and degradation (fatty acid amide hydrolase (FAAH); monoacylglycerol lipase (MAGL)) were identified.
Studies on the expression and localization of the cannabinoid receptors in the brain have burgeoned in the last decade and have furnished valuable data on their putative involvement in various sensory-motor and cognitive functions in diverse animal species, including Man. These studies have recently received substantial attention from pharmaceutical companies as a potential source for novel treatments. Additionally, the dilemma of legalizing the use of cannabis in some countries makes the investigation on cannabinoid systems more momentous. This special issue is therefore timely and brings historical and groundbreaking novel research on the role of these cannabinoid receptors in the mammalian central nervous system (CNS).
We hope that the collected papers in this special issue will contribute to the understanding of the various mechanisms involved in the functions of the endocannabinoid system and the development of new pharmaceutical tools to treat visual disorders.”
Inhibition of autophagy and enhancement of endoplasmic reticulum stress increase sensitivity of osteosarcoma Saos-2 cells to cannabinoid receptor agonist WIN55,212-2.
“WIN55,212-2, a cannabinoid receptor agonist, can activate cannabinoid receptors, which has proven anti-tumour effects in several tumour types. Studies showed that WIN can inhibit tumour cell proliferation and induce apoptosis in diverse cancers.
However, the role and mechanism of WIN in osteosarcoma are still unclear. In this study, we examined the effect of WIN55,212-2 on osteosarcoma cell line Saos-2 in terms of cell viability and apoptosis. Meanwhile, we further explored the role of endoplasmic reticulum stress and autophagy in apoptosis induced by WIN55,212-2.
Our results showed that the cell proliferation of Saos-2 was inhibited by WIN55,212-2 in a dose-dependent and time-dependent manner. WIN55,212-2-induced Saos-2 apoptosis through mitochondrial apoptosis pathway. Meanwhile, WIN55,212-2 can induce endoplasmic reticulum stress and autophagy in Saos-2 cells. Inhibition of autophagy and enhancement of endoplasmic reticulum stress increased apoptosis induced by WIN55,212-2 in Saos-2 cells.
These findings indicated that WIN55,212-2 in combination with autophagic inhibitor or endoplasmic reticulum stress activator may shed new light on osteosarcoma treatment.”