Angiopoietin-related growth factor antagonizes obesity and insulin resistance

Area of Science:

• Metabolic research
• Endocrinology
• Obesity research

Background:

• Angiopoietin-related growth factor (AGF) is a protein secreted by the liver.
• The angiopoietin-like protein (Angptl) family includes AGF.
• The role of AGF in metabolic regulation is not fully understood.

Purpose of the Study:

• To investigate the physiological role of AGF in metabolic regulation.
• To determine the effects of AGF deficiency and activation on body weight, lipid metabolism, and insulin sensitivity.
• To explore AGF as a potential therapeutic target for obesity and related metabolic disorders.

Main Methods:

• Generation and analysis of AGF-deficient mice.
• Targeted activation of AGF in mice.
• Adenoviral transduction for hepatic AGF overexpression.
• Assessment of body weight, body composition, glucose tolerance, insulin sensitivity, and energy expenditure.
• High-fat diet feeding studies.

Main Results:

• AGF-deficient mice exhibit high embryonic lethality, with survivors developing obesity, hepatic and skeletal muscle steatosis, and insulin resistance due to reduced energy expenditure.
• Targeted AGF activation leads to leanness, increased insulin sensitivity, and elevated energy expenditure.
• Mice with AGF activation are protected against high-fat diet-induced obesity, insulin resistance, and non-adipose tissue steatosis.
• Hepatic AGF overexpression significantly reduces body weight and improves insulin sensitivity in mice on a high-fat diet.

Conclusions:

• AGF is a critical hepatocyte-derived circulating factor that plays a significant role in counteracting obesity and insulin resistance.
• AGF acts by increasing energy expenditure, thereby preventing obesity and improving metabolic health.
• AGF represents a promising novel therapeutic target for the management of obesity and associated metabolic complications.