Abstract
Aims: Emerging evidence implicates CB2R, a key component of the endocannabinoid signalling (ECS) system, in the control of adiposity and metabolic function by as yet poorly understood mechanisms. Herein, we explore how CB2R modulation in human adipocytes affects processes linked to the activation of AMP-activated protein kinase (AMPK), a key cellular energy sensor and mitochondrial respiratory capacity.
Methods: Using human Simpson–Golabi–Behmel syndrome (SGBS) adipocytes as a model system, we examined changes in AMPK-dependent signalling by immunoblotting following provision of a selective CB2R agonist (AM1241) and inverse antagonist (SR144528). In addition, CB2R modulation by these ligands upon radiolabelled 2-deoxyglucose uptake and mitochondrial oxidative capacity, using a Seahorse XF24 Extracellular Flux Analyzer, was determined.
Results: Differentiated SGBS adipocytes express CB2R and treatment with AM1241 significantly increased AMPK-Thr172 phosphorylation (1.7-fold), and that of its downstream substrate acetyl-CoA carboxylase (ACC) (2.2-fold), indicative of AMPK activation. Notably, the stimulatory action of AM1241 upon AMPK was found to be dependent on nitric oxide production via nitric oxide synthase (NOS). Allied to this, CB2R stimulation increased glucose uptake (1.3-fold; p < 0.05) and oxygen consumption (1.6-fold; p < 0.05) rates in SGBS adipocytes.
Conclusions: Our data implicate CB2R in the modulation of AMPK-dependent signalling in human adipocytes through a NOS-dependent pathway. Associated improvements in adipocyte glucose transport and mitochondrial oxidative capacity suggest that CB2R may be a promising therapeutic target for mitigating obesity-related metabolic dysfunction.
Methods: Using human Simpson–Golabi–Behmel syndrome (SGBS) adipocytes as a model system, we examined changes in AMPK-dependent signalling by immunoblotting following provision of a selective CB2R agonist (AM1241) and inverse antagonist (SR144528). In addition, CB2R modulation by these ligands upon radiolabelled 2-deoxyglucose uptake and mitochondrial oxidative capacity, using a Seahorse XF24 Extracellular Flux Analyzer, was determined.
Results: Differentiated SGBS adipocytes express CB2R and treatment with AM1241 significantly increased AMPK-Thr172 phosphorylation (1.7-fold), and that of its downstream substrate acetyl-CoA carboxylase (ACC) (2.2-fold), indicative of AMPK activation. Notably, the stimulatory action of AM1241 upon AMPK was found to be dependent on nitric oxide production via nitric oxide synthase (NOS). Allied to this, CB2R stimulation increased glucose uptake (1.3-fold; p < 0.05) and oxygen consumption (1.6-fold; p < 0.05) rates in SGBS adipocytes.
Conclusions: Our data implicate CB2R in the modulation of AMPK-dependent signalling in human adipocytes through a NOS-dependent pathway. Associated improvements in adipocyte glucose transport and mitochondrial oxidative capacity suggest that CB2R may be a promising therapeutic target for mitigating obesity-related metabolic dysfunction.
| Original language | English |
|---|---|
| Article number | P56 |
| Pages (from-to) | 54 |
| Number of pages | 1 |
| Journal | Diabetic Medicine |
| Volume | 35 |
| Issue number | S1 |
| Early online date | 14 Mar 2018 |
| DOIs | |
| Publication status | Published - Mar 2018 |
