β-arrestin-1 suppresses myogenic reprogramming of brown fat to maintain euglycemia

Area of Science:

• Metabolic signaling pathways
• Adipocyte function regulation
• Brown adipose tissue (BAT) biology

Background:

• Understanding adipocyte signaling is key for developing antidiabetic and anti-obesity drugs.
• Beta-arrestin-1 (barr1) is a cytoplasmic and nuclear signaling protein with roles in various cellular processes.

Purpose of the Study:

• To investigate the role of beta-arrestin-1 (barr1) in adipocytes and brown adipose tissue (BAT) in metabolic regulation.
• To determine the impact of barr1 deficiency or overexpression in adipocytes on glucose tolerance and insulin sensitivity.

Main Methods:

• Generation of mice with selective deletion or overexpression of barr1 in adipocytes.
• Feeding mice an obesogenic (high-calorie) diet to induce metabolic deficits.
• Measurement of glucose tolerance, insulin sensitivity, plasma myostatin (Mstn) levels, and insulin signaling in peripheral tissues.

Main Results:

• Mice lacking barr1 in adipocytes exhibited impaired glucose tolerance and insulin sensitivity on an obesogenic diet.
• Overexpression of barr1 in adipocytes protected against diet-induced metabolic deficits.
• Barr1 deficiency induced myogenic reprogramming of BAT, increasing plasma myostatin (Mstn) and impairing insulin signaling.

Conclusions:

• Beta-arrestin-1 (barr1) is a critical regulator of brown adipose tissue (BAT) function and overall metabolic homeostasis.
• Barr1-mediated suppression of myostatin (Mstn) in BAT is essential for maintaining normal blood glucose levels (euglycemia).
• Targeting barr1 activity in BAT presents a potential therapeutic strategy for type 2 diabetes and obesity.