CB1 and GLP-1 Receptors Cross Talk Provides New Therapies for Obesity

Area of Science:

• Metabolic disorders
• Endocrinology
• Pharmacology

Background:

• Glucagon-like peptide 1 receptor (GLP-1R) agonists improve glycemic control and body weight in type 2 diabetes and obesity.
• However, their weight-lowering efficacy is limited, and they have minimal insulin-sensitizing effects.
• Peripherally restricted cannabinoid receptor type 1 (CB1R) inhibitors, unlike brain-penetrant ones, mitigate obesity and metabolic complications without neuropsychiatric side effects.

Purpose of the Study:

• To investigate the reciprocal functional interactions between CB1R and GLP-1R in modulating food intake and body weight.
• To evaluate the efficacy of coadministering peripheral CB1R inhibitors with GLP-1R agonists in diet-induced obese mice.

Main Methods:

• Utilized mouse models with genetic deletion of CB1R or GLP-1R.
• Administered a peripheral CB1R inhibitor in combination with long-acting GLP-1R agonists to diet-induced obese mice.
• Assessed body weight, fat mass, energy balance, insulin action, dyslipidemia, and hepatic steatosis.

Main Results:

• Coadministration of peripheral CB1R inhibitor and GLP-1R agonists resulted in greater reductions in body weight and fat mass compared to monotherapies.
• The combination therapy promoted a negative energy balance.
• Significant improvements were observed in systemic and hepatic insulin action, systemic dyslipidemia, and hepatic steatosis.

Conclusions:

• Peripheral CB1R blockade can safely potentiate the antiobesity and antidiabetic effects of GLP-1R agonists.
• This combination strategy offers a promising approach for managing type 2 diabetes and obesity.
• Reciprocal interactions between CB1R and GLP-1R pathways are crucial for metabolic regulation.