Hepatic CB1 receptor signaling triggers Gi/oα-mediated lipolysis in lean mice but Gsα-mediated lipogenesis in obese mice
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1302424 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Objectives: Obesity-induced steatotic liver disease (SLD) is driven by the uptake of adipocyte-derived fatty acids (FAs) into hepatocytes via the FA translocase CD36, which also prevents their consumption by inhibiting AMP kinase (AMPK)-mediated FA oxidation (FAO). We explored the role of hepatocyte CB1 receptors (hCB1R) in controlling hepatic triglyceride (TG) content by regulating CD36 and its downstream targets. Methods: hCB1R knockout (hCB1Rko) mice and their control littermates kept on standard or high-fat diet were used to analyze hCB1R-mediated hepatic gene expression profile and lipid metabolism in intact mice and in cultured hepatocytes. Results: Multi-omics data indicate that hCB1R target a distinct set of genes associated with SLD, including Cd36. In mice with diet-induced obesity, hCB1R signaling via CD36-AMPK-FAO pathway contributes to both the development of SLD and its reversal by CB1R blockade. But, in lean mice hCB1R signaling inhibits CD36 expression and activates AMPK-mediated FAO. These opposite effects were replicated in AML12 mouse hepatocytes incubated with or without oleic acid (OA). OA, an endogenous ligand of GPR3, induced a switch in hCB1R signaling from a Gi/oα-mediated reduction in cAMP to a Gsα-mediated increase in cAMP in a GPR3/Gsα -dependent manner, facilitated by increasing the ratio of Gsα:Gi/oα proteins in the steatotic compared to lean liver. Conclusions: In the lean state, endocannabinoid activation of hCB1R increases FAO, which mitigates SLD, as reported for chronic marihuana smokers, whereas in obese mice hCB1R tonically inhibit FAO, which promotes SLD and underlies the anti-steatotic effect of peripheral CB1R blockade.
2025-08-06 | GSE304736 | GEO
Project description:Long-lasting forms of postsynaptic plasticity commonly involve protein synthesis-dependent structural changes of dendritic spines. However, the relationship between protein synthesis and presynaptic structural plasticity remains unclear. Here, we investigated structural changes in cannabinoid-receptor 1 (CB1)-mediated long-term depression of inhibitory transmission (iLTD), a form of presynaptic plasticity that requires protein synthesis and involves a long-lasting reduction in GABA release. We found that CB1-iLTD in acute rat hippocampal slices was associated with protein synthesis-dependent presynaptic structural changes. Using proteomics, we determined that CB1 activation in hippocampal neurons resulted in increased ribosomal proteins and initiation factors, but decreased levels of proteins involved in regulation of the actin cytoskeleton, such as Arp2/3, and presynaptic release. Moreover, while CB1-iLTD increased ubiquitin/proteasome activity, ubiquitination but not proteasomal degradation was critical for structural and functional presynaptic CB1-iLTD. Thus, CB1-iLTD relies on both protein synthesis and ubiquitination to elicit structural changes that underlie long-term reduction of GABA release.
2020-09-23 | PXD020008 | Pride
Project description:The cannabinoid 1 receptor (CB1) regulates insulin sensitivity and glucose metabolism in peripheral tissues. CB1 is expressed on pancreatic beta (β)-cells where its functions have not been fully described. We generated a β-cell-specific CB1-knockout (β-CB1-/-) mouse to study the long-term consequences of CB1 ablation on β-cell function in adult mice. β-CB1-/- mice had increased basal- and stimulated-insulin secretion and intra-islet cAMP levels, resulting in primary hyperinsulinemia, as well as increased β-cell viability, proliferation, and islet area. Hyperinsulinemia led to insulin resistance, which was aggravated by a high fat/high glucose diet and weight gain, although β-cells maintained their insulin secretory capacity in response to glucose. Strikingly, islets from β-CB1-/- mice were protected from diet-induced inflammation. Mechanistically we show that this is a consequence of curtailment of oxidative stress and reduced activation of Nlrp3 inflammasome in β-cells. Our data demonstrate CB1 to be a negative regulator of β-cells and a mediator of islet inflammation under conditions of metabolic stress.
2018-03-07 | GSE102027 | GEO
Project description:In the present study, we investigated the role of endothelial Gsα in post-ischemic angiogenesis.
2022-07-21 | GSE206934 | GEO
Project description:Although the cannabinoid CB1 receptor has been implicated in atherosclerosis, its cellspecific effects in this disease are not well understood. Here, we report that male mice with myeloid-specific Cnr1 deficiency on atherogenic background developed smaller lesions and necrotic cores than controls, while only minor genotype differences were observed in females. Male Cnr1 deficient mice showed reduced arterial monocyte recruitment and macrophage proliferation with less inflammatory phenotype. The sexspecific differences in proliferation were dependent on estrogen receptor (ER)α estradiol signaling. Kinase activity profiling revealed a CB1-dependent regulation of p53 and cyclin-dependent kinases. Transcriptomic profiling further unveiled chromatin modifications, mRNA processing and mitochondrial respiration among the key processes affected by CB1 signaling, which was supported by metabolic flux assays. Chronic administration of the peripherally-restricted CB1 antagonist JD5037 inhibited plaque progression and macrophage proliferation, but only in male mice. Finally, CNR1 expression was detectable in human carotid endarterectomy plaques and inversely correlated with proliferation, oxidative metabolism and inflammatory markers, hinting to a possible implication of CB1-dependent regulation in human pathophysiology. In conclusion, impaired macrophage CB1 signaling is atheroprotective by limiting their arterial recruitment, proliferation and inflammatory reprogramming. The importance of macrophage CB1 signaling seems to be more pronounced in male mice.
2023-12-07 | GSE249503 | GEO
Project description:SnoRNA antagonizes IL-15-mediated lipolysis and promotes obesity
| PRJNA880887 | ENA
Project description:Peripherally restricted cannabinoid CB1 receptor antagonists without central side effects hold promise for treating metabolic disorders including diabetes and obesity. In atherosclerosis, the specific effects of peripheral CB1 signaling in vascular endothelial cells (ECs) remain incompletely understood.We performed en face in situ hybridization of Cnr1 in murine aortas, revealing a significantly increased expression of the CB1 encoding gene in ECs within atheroprone compared to atheroresistant regions. In vitro, CNR1 was upregulated by oscillatory shear stress in human aortic endothelial cells (HAoECs). Endothelial CB1 deficiency (Cnr1EC-KO) in female mice on atherogenic background resulted in pronounced endothelial phenotypic changes, with reduced vascular inflammation and permeability. This translated into attenuated plaque development with reduced lipid content as well as reduced white and brown adipose tissue mass and liver steatosis. Ex vivo imaging of carotid arteries via two-photon microscopy revealed less DIL-LDL uptake in Cnr1EC-KO. This was accompanied by a significant reduction of aortic endothelial caveolin-1 (CAV1) expression, a key structural protein involved in lipid transcytosis in female Cnr1EC-KO mice. In vitro, pharmacological blocking with CB1 antagonist AM281 reproduced the inhibition of CAV1 expression and LDL uptake in response to atheroprone shear stress in human aortic endothelial cells (HAoECs), which was dependent on cAMP-mediated PKA activation. Conversely, the CB1 agonist ACEA increased DIL-LDL uptake and CAV1 expression in HAoECs. Finally, treatment of atherosclerotic mice with the peripheral CB1 antagonist JD-5037 reduced plaque progression, CAV1 and endothelial adhesion molecule expression in female mice. These results confirm an essential role of endothelial CB1 to the pathogenesis of atherosclerosis.
2024-04-04 | GSE260826 | GEO
Project description:To investigate the corelation of genes regualted by CB1
2022-06-01 | GSE173906 | GEO
Project description:Feline hyperthyroidism (FHT) is a debilitating disease affecting >10% of elderly cats. It is generally characterised by chronic elevation of thyroid hormone in the absence of circulating TSH. Understanding of the molecular pathogenesis of FHT is currently limited. However, FHT shares clinical and histopathological similarities with human toxic multinodular goitre, which has been associated with activating mutations in TSH receptor (TSHR) and Gsα encoding genes. Using RNA-seq transcriptomic analysis of thyroid tissue from hyperthyroid and euthyroid cats, we identified differentially expressed genes and dysregulated pathways in FHT, many of which are downstream of TSHR. In addition, we detected missense variants in thyroid RNA-seq reads that alter the structure of both TSHR and Gsα. All FHT-associated mutations were absent in germline sequence from paired blood samples. Only a small number of hyperthyroid cats demonstrated TSHR variation, however all thyroids from advanced cases of FHT carried at least one missense variant affecting Gsα. The activating nature of the acquired Gsα mutations was demonstrated by increased cAMP production in vitro. These data indicate that constitutive activation of signalling downstream of TSHR is central to the TSH-independent production of thyroid hormone in FHT, offering a novel therapeutic target pathway in this common disease.
2024-09-07 | GSE276271 | GEO