Visualization and Quantification of Browning Using a Ucp1-2A-Luciferase Knock-in Mouse Model

Area of Science:

• Metabolic research
• Adipose tissue biology
• Obesity and metabolic disease research

Background:

• Brown and beige adipocytes are crucial for energy expenditure and combating metabolic diseases.
• Uncoupling protein 1 (Ucp1) is a key marker for brown and beige adipocyte function.
• Accurate measurement of Ucp1 expression is vital for studying thermogenesis.

Purpose of the Study:

• To develop a sensitive tool for measuring Ucp1 expression in vivo and in vitro.
• To identify novel adipose tissue depots and potential therapeutic agents for obesity.

Main Methods:

• Generation of a Ucp1-2A-luciferase knock-in mouse model.
• Utilizing luciferase activity for quantitative and visualization studies of Ucp1 expression.
• Screening for compounds that induce 'browning' of adipose tissue.

Main Results:

• The Ucp1-2A-luciferase mouse model accurately reflects Ucp1 gene expression.
• Discovery of a novel, cold-sensitive brown/beige adipose depot in the ear (uBAT).
• Identification of axitinib as an effective 'browning' agent.

Conclusions:

• The Ucp1-2A-luciferase mouse is a valuable tool for studying thermogenesis and adipocyte function.
• The uBAT depot represents a new area for metabolic research.
• Axitinib shows promise as a therapeutic agent for obesity and related metabolic disorders.