“Endocannabinoids (eCBs) are internal lipid mediators recognized by the cannabinoid-1 and -2 receptors (CB1R and CB2R, respectively), which also mediate the different physiological effects of marijuana. The endocannabinoid system, consisting of eCBs, their receptors, and the enzymes involved in their biosynthesis and degradation, is present in a vast number of peripheral organs. In this review we describe the role of the eCB/CB1R system in modulating the metabolism in several peripheral organs. We assess how eCBs, via activating the CB1R, contribute to obesity and regulate food intake. In addition, we describe their roles in modulating liver and kidney functions, as well as bone remodeling and mass. Special importance is given to emphasizing the efficacy of the recently developed peripherally restricted CB1R antagonists, which were pre-clinically tested in the management of energy homeostasis, and in ameliorating both obesity- and diabetes-induced metabolic complications.”
Category Archives: Obesity
Peripheral modulation of the endocannabinoid system in metabolic disease.
“Dysfunction of the endocannabinoid system (ECS) has been identified in metabolic disease.
Cannabinoid receptor 1 (CB1) is abundantly expressed in the brain but also expressed in the periphery. Cannabinoid receptor 2 (CB2) is more abundant in the periphery, including the immune cells.
In obesity, global antagonism of overexpressed CB1 reduces bodyweight but leads to centrally mediated adverse psychological outcomes.
Emerging research in isolated cultured cells or tissues has demonstrated that targeting the endocannabinoid system in the periphery alleviates the pathologies associated with metabolic disease.
Further, peripheral specific cannabinoid ligands can reverse aspects of the metabolic phenotype.
This Keynote review will focus on current research on the functionality of peripheral modulation of the ECS for the treatment of obesity.”
Prospects for the Use of Cannabinoid Receptor Ligands for the Treatment of Metabolic Syndrome and Atherosclerosis: Analysis of Experimental and Clinical Data.
“An antagonist of central cannabinoid CB1 receptors rimonabant causes weight loss in patients with obesity and metabolic syndrome, improves blood lipid parameters, increases the adiponectin level, decreases the rate of glucose and glycosylated hemoglobin in patients with diabetes mellitus type-2. However, rimonabant adverse effects include depression, anxiety, nausea, and dizziness which are apparently due to the blockade of central CB1 receptors.
In mice with a high-calorie diet, we defined that the blockade of peripheral CB1 receptors prevents obesity, steatosis of the liver, improves lipid and carbohydrate metabolism. Experimental studies suggest that peripheral CB2 receptor agonists have antiatherogenic effect. To validate the expediency of clinical research of CB2 receptor agonists in patients with atherosclerosis the comparative analysis of antiatherogenic properties of cannabinoids should be performed. In addition, experiments are needed on the combination use of cannabinoids with well-known antiatherogenic agents, such as statins.”
Novel Peripherally Restricted Cannabinoid 1 Receptor Selective Antagonist TXX-522 with Prominent Weight-Loss Efficacy in Diet Induced Obese Mice.
“The clinical development of the first generation of globally active cannabinoid 1 receptor (CB1R) antagonists was suspended because of their adverse neuropsychiatric effects. Selective blockade of peripheral CB1Rs has the potential to provide a viable strategy for the treatment of severe obesity while avoiding these central nervous system side effects.
In the current study, a novel compound (TXX-522) was rationally designed based on the parent nucleus of a classical CB1R-selective antagonist/inverse agonist, rimonabant (SR141716A).
TXX-522 showed good binding, CB1R-selectivity (over the CB2R), and functional antagonist activities in a range of in vitro molecular and cellular assays.
In vivo analysis of the steady state distribution of TXX-522 in the rat brain and blood tissues and the assay of its functional effects on CB1R activity collectively showed that TXX-522 showed minimal brain penetration. Moreover, the in vivo pharmacodynamic study further revealed that TXX-522 had good oral bioavailability and a potent anti-obesity effect, and ameliorated insulin resistance in high-fat diet-induced obese mice. No impact on food intake was observed in this model, confirming the limited brain penetration of this compound.
Thus, the current study indicates that TXX-522 is a novel and potent peripherally acting selective CB1R antagonist with the potential to control obesity and related metabolic disorders.”
https://www.ncbi.nlm.nih.gov/pubmed/29051736
https://www.frontiersin.org/articles/10.3389/fphar.2017.00707/full
Perinatal maternal high-fat diet induces early obesity and sex-specific alterations of the endocannabinoid system in white and brown adipose tissue of weanling rat offspring.
“Perinatal maternal high-fat (HF) diet programmes offspring obesity. Obesity is associated with overactivation of the endocannabinoid system (ECS) in adult subjects, but the role of the ECS in the developmental origins of obesity is mostly unknown. The ECS consists of endocannabinoids, cannabinoid receptors (cannabinoid type-1 receptor (CB1) and cannabinoid type-2 receptor (CB2)) and metabolising enzymes.
We hypothesised that perinatal maternal HF diet would alter the ECS in a sex-dependent manner in white and brown adipose tissue of rat offspring at weaning in parallel to obesity development.
Maternal HF diet induced early obesity, white adipocyte hypertrophy and increased lipid accumulation in brown adipose tissue associated with sex-specific changes of the ECS’s components in weanling rats. In male pups, maternal HF diet decreased CB1 and CB2 protein in subcutaneous adipose tissue. In female pups, maternal HF diet increased visceral and decreased subcutaneous CB1. In brown adipose tissue, maternal HF diet increased CB1 regardless of pup sex. In addition, maternal HF diet differentially changed oestrogen receptor across the adipose depots in male and female pups.
The ECS and oestrogen signalling play an important role in lipogenesis, adipogenesis and thermogenesis, and we observed early changes in their targets in adipose depots of the offspring. The present findings provide insights into the involvement of the ECS in the developmental origins of metabolic disease induced by inadequate maternal nutrition in early life.”
Maternal high-fat diet induces sex-specific endocannabinoid system changes in newborn rats and programs adiposity, energy expenditure and food preference in adulthood.
“Early life inadequate nutrition triggers developmental adaptations and adult chronic disease.
Maternal high-fat (HF) diet promotes visceral obesity and hypothalamic leptin resistance in male rat offspring at weaning and adulthood.
Obesity is related to over active endocannabinoid system (ECS). The ECS consists mainly of endogenous ligands, cannabinoid receptors (CB1 and CB2), and the enzymes fatty acid anandamide hydrolase (FAAH) and monoacylglycerol lipase (MAGL).
We hypothesized that perinatal maternal HF diet would regulate offspring ECS in hypothalamus and brown adipose tissue (BAT) at birth, prior to visceral obesity development, and program food preference and energy expenditure of adult offspring.
In conclusion, maternal HF diet alters ECS components and energy metabolism targets in hypothalamus and BAT of offspring at birth, in a sex-specific manner, which may contribute for hyperphagia, food preference and higher adiposity later in life.”
https://www.ncbi.nlm.nih.gov/pubmed/29102876
http://www.sciencedirect.com/science/article/pii/S0955286317303042?via%3Dihub
Novel Peripherally Restricted Cannabinoid 1 Receptor Selective Antagonist TXX-522 with Prominent Weight-Loss Efficacy in Diet Induced Obese Mice.
“The clinical development of the first generation of globally active cannabinoid 1 receptor (CB1R) antagonists was suspended because of their adverse neuropsychiatric effects. Selective blockade of peripheral CB1Rs has the potential to provide a viable strategy for the treatment of severe obesity while avoiding these central nervous system side effects.
In the current study, a novel compound (TXX-522) was rationally designed based on the parent nucleus of a classical CB1R-selective antagonist/inverse agonist, rimonabant (SR141716A). Docking assays indicate that TXX-522 was bound with the CB1R in a mode similar to that of SR141716A. TXX-522 showed good binding, CB1R-selectivity (over the CB2R), and functional antagonist activities in a range of in vitro molecular and cellular assays.
In vivo analysis of the steady state distribution of TXX-522 in the rat brain and blood tissues and the assay of its functional effects on CB1R activity collectively showed that TXX-522 showed minimal brain penetration. Moreover, the in vivopharmacodynamic study further revealed that TXX-522 had good oral bioavailability and a potent anti-obesity effect, and ameliorated insulin resistance in high-fat diet-induced obese mice. No impact on food intake was observed in this model, confirming the limited brain penetration of this compound.
Thus, the current study indicates that TXX-522 is a novel and potent peripherally acting selective CB1R antagonist with the potential to control obesity and related metabolic disorders.”
https://www.ncbi.nlm.nih.gov/pubmed/29051736
https://www.frontiersin.org/articles/10.3389/fphar.2017.00707/full
Cannabis in fat: high hopes to treat obesity.
“Cannabinoid receptor type-1 (CB1s) is known to have a substantial impact on the regulation of energy metabolism via central and peripheral mechanisms. In this issue of the JCI, Ruiz de Azua and colleagues provide important insights into the regulation of adipocyte physiology by CB1. Mice with adipocyte-specific deletion of the CB1-encoding gene had an overall improved metabolic profile in addition to reduced body weight and total adiposity. These changes were associated with an increase in sympathetic tone of the adipose tissue and expansion of activated macrophages, both of which occurred prior to changes in body weight, lending support to a causal relationship between loss of CB1 in adipocytes and systemic metabolic changes. This work identifies adipocyte CB1s as a potential novel peripheral target for affecting systemic metabolism with diminished CNS effects.”
Adipocyte cannabinoid receptor CB1 regulates energy homeostasis and alternatively activated macrophages.
“Dysregulated adipocyte physiology leads to imbalanced energy storage, obesity, and associated diseases, imposing a costly burden on current health care.
Cannabinoid receptor type-1 (CB1) plays a crucial role in controlling energy metabolism through central and peripheral mechanisms.
In this work, adipocyte-specific inducible deletion of the CB1 gene (Ati-CB1-KO) was sufficient to protect adult mice from diet-induced obesity and associated metabolic alterations and to reverse the phenotype in already obese mice. Compared with controls, Ati-CB1-KO mice showed decreased body weight, reduced total adiposity, improved insulin sensitivity, enhanced energy expenditure, and fat depot-specific cellular remodeling toward lowered energy storage capacity and browning of white adipocytes. These changes were associated with an increase in alternatively activated macrophages concomitant with enhanced sympathetic tone in adipose tissue.
Remarkably, these alterations preceded the appearance of differences in body weight, highlighting the causal relation between the loss of CB1 and the triggering of metabolic reprogramming in adipose tissues. Finally, the lean phenotype of Ati-CB1-KO mice and the increase in alternatively activated macrophages in adipose tissue were also present at thermoneutral conditions.
Our data provide compelling evidence for a crosstalk among adipocytes, immune cells, and the sympathetic nervous system (SNS), wherein CB1 plays a key regulatory role.”
Peripheral cannabinoid-1 receptor blockade restores hypothalamic leptin signaling.
“In visceral obesity, an overactive endocannabinoid/CB1 receptor (CB1R) system promotes increased caloric intake and decreases energy expenditure, which are mitigated by global or peripheral CB1R blockade. In mice with diet-induced obesity (DIO), inhibition of food intake by the peripherally restricted CB1R antagonist JD5037 could be attributed to endogenous leptin due to the rapid reversal of hyperleptinemia that maintains leptin resistance, but the signaling pathway engaged by leptin has remained to be determined.
METHODS:
We analyzed the hypothalamic circuitry targeted by leptin following chronic treatment of DIO mice with JD5037.
RESULTS:
Leptin treatment or an increase in endogenous leptin following fasting/refeeding induced STAT3 phosphorylation in neurons in the arcuate nucleus (ARC) in lean and JD5037-treated DIO mice, but not in vehicle-treated DIO animals. Co-localization of pSTAT3 in leptin-treated mice was significantly less common with NPY+ than with POMC+ ARC neurons. The hypophagic effect of JD5037 was absent in melanocortin-4 receptor (MC4R) deficient obese mice or DIO mice treated with a MC4R antagonist, but was maintained in NPY-/- mice kept on a high-fat diet.
CONCLUSIONS:
Peripheral CB1R blockade in DIO restores sensitivity to endogenous leptin, which elicits hypophagia via the re-activation of melanocortin signaling in the ARC.”
https://www.ncbi.nlm.nih.gov/pubmed/29031713
http://www.molmetab.com/article/S2212-8778(17)30327-7/fulltext