Category Archives: Obesity
Identification of novel mouse and rat CB1R isoforms and in silico modeling of human CB1R for peripheral cannabinoid therapeutics.
“Targeting peripheral CB1R is desirable for the treatment of metabolic syndromes without adverse neuropsychiatric effects.
We previously reported a human hCB1b isoform that is selectively enriched in pancreatic beta-cells and hepatocytes, providing a potential peripheral therapeutic hCB1R target. It is unknown whether there are peripherally enriched mouse and rat CB1R (mCB1 and rCB1, respectively) isoforms.
In this study, we found no evidence of peripherally enriched rodent CB1 isoforms; however, some mCB1R isoforms are absent in peripheral tissues. We show that the mouse Cnr1 gene contains six exons that are transcribed from a single promoter. We found that mCB1A is a spliced variant of extended exon 1 and protein-coding exon 6; mCB1B is a novel spliced variant containing unspliced exon 1, intron 1, and exon 2, which is then spliced to exon 6; and mCB1C is a spliced variant including all 6 exons.
Using RNAscope in situ hybridization, we show that the isoforms mCB1A and mCB1B are expressed at a cellular level and colocalized in GABAergic neurons in the hippocampus and cortex. RT-qPCR reveals that mCB1A and mCB1B are enriched in the brain, while mCB1B is not expressed in the pancreas or the liver. Rat rCB1R isoforms are differentially expressed in primary cultured neurons, astrocytes, and microglia.
We also investigated modulation of Cnr1 expression by insulin in vivo and carried out in silico modeling of CB1R with JD5037, a peripherally restricted CB1R inverse agonist, using the published crystal structure of hCB1R.
The results provide models for future CB1R peripheral targeting.”
Role of Cannabinoids in Obesity.
“Obesity is an increasing health problem worldwide. Its related comorbidities imply a high cost for the National Health System and diminish a patient’s life quality.
Adipose tissue is composed of three types of cells. White adipocytes are involved in fat storage and secretion of hormones. Brown adipocytes are involved in thermogenesis and caloric expenditure. Beige adipocytes are transitional adipocytes that in response to various stimuli can turn from white to brown and could be protective against the obesity, enhancing energy expenditure.
The conversion of white in beige adipose tissue is a potential new therapeutic target for obesity.
Cannabinoid receptors (CB) regulate thermogenesis, food intake and inflammation. CB1 ablation or inhibition helps reducing body weight and food intake. Stimulation of CB2 limits inflammation and promotes anti-obesity effects by reducing food intake and weight gain. Its genetic ablation results in adiposity development.
CB receptors are also responsible for transforming white adipose tissue towards beige or brown adipocytes, therefore their modulation can be considered potential anti-obesity target. CB1 principal localization in central nervous system represents an important limit. Stimulation of CB2, principally localized on peripheral cells instead, should facilitate the anti-obesity effects without exerting remarkable psychotropic activity.”
https://www.ncbi.nlm.nih.gov/pubmed/30201891
http://www.mdpi.com/1422-0067/19/9/2690
“Maintenance of body weight is fundamental to maintain one’s health and to promote longevity. Nevertheless, it appears that the global obesity epidemic is still constantly increasing.
Endocannabinoids (eCBs) are lipid messengers that are involved in overall body weight control by interfering with manifold central and peripheral regulatory circuits that orchestrate energy homeostasis.
Initially, blocking of eCB signaling by first generation
“The endocannabinoids are now known as novel and important regulators of energy metabolism and homeostasis.
The endocrine functions of white adipose are chiefly involved in the control of whole-body metabolism, insulin sensitivity and food intake. Adipocytes produce hormones, such as leptin and adiponectin, that can improve insulin resistance or peptides, such as TNF-α, that elicit insulin resistance. Adipocytes express specific receptors, such as peroxisome proliferator-activated receptor (PPAR)-γ, which serve as adipocyte targets for insulin sensitizers such as thiazolidinediones.
Recently, endocannabinoids and related compounds were identified in human fat cells.
The endocannabinoid system consists primarily of two receptors,
“Patients with obesity are susceptible to hypertension and diabetes. Over-activation of
“Activating brown adipose tissue (BAT) could provide a potential approach for the treatment of obesity and metabolic disease in humans.
Obesity is associated with up-regulation of the endocannabinoid system, and blocking the
“The use of different natural and/or synthetic preparations of Cannabis sativa is associated with therapeutic strategies for many diseases. Indeed, thanks to the widespread diffusion of the cannabinoidergic system in the brain and in the peripheral districts, its stimulation, or inhibition, regulates many pathophysiological phenomena.
In particular, central activation of the cannabinoidergic system modulates the limbic and mesolimbic response which leads to food craving.
Moreover,
“White adipose tissue (WAT) stores excess energy as triglycerides, and brown adipose tissue (BAT) is specialized in dissipating energy as heat. The endocannabinoid system (ECS) is involved in a broad range of physiological processes and is increasingly recognized as a key player in adipose tissue metabolism. High ECS tonus in the fed state is associated with a disadvantageous metabolic phenotype, and this has led to a search for pharmacological strategies to inhibit the ECS. In this review we present recent developments that cast light on the regulation of adipose tissue metabolism by the ECS, and we discuss novel treatment options including the modulation of endocannabinoid synthesis and breakdown enzymes.”