Through fat and thin - a journey with the adipose tissues

Area of Science:

• Cellular and Molecular Nutrition
• Nutritional Energetics
• Adipose Tissue Biology

Background:

• The study reviews research on brown and white adipose tissues, focusing on their roles in obesity and metabolic regulation.
• Initial research explored metabolic factors in obesity development using animal models, leading to interest in non-shivering thermogenesis.
• Subsequent research shifted to white adipose tissue, investigating its endocrine and signaling functions in obesity.

Purpose of the Study:

• To review key studies on brown and white adipose tissues conducted by the author's research groups.
• To highlight the role of adipose tissue in nutritional energetics, obesity, and inflammation.
• To propose oxygen as a critical macronutrient based on hypoxia studies in white adipocytes.

Main Methods:

• Utilized animal models to study metabolic factors underlying obesity.
• Investigated non-shivering thermogenesis in brown adipose tissue.
• Examined nutritional regulation of Ob gene expression and leptin levels in white adipose tissue.

Main Results:

• Brown adipose tissue is a key effector of facultative heat production, with altered activity in obese rodents and during physiological states.
• Nutritional regulation and sympathetic nervous system influence (via β3-adrenoceptors) on Ob gene expression and leptin levels were demonstrated.
• Hypoxia in white adipose tissue was shown to underlie inflammation and affect gene expression and cellular function, leading to the proposal of oxygen as a macronutrient.

Conclusions:

• Adipose tissue, both brown and white, plays a crucial role in nutritional energetics and metabolic regulation.
• Obesity is associated with altered adipose tissue function, including reduced thermogenesis in brown fat and inflammation in white fat.
• Oxygen should be considered a critical macronutrient due to its profound effects on white adipocyte function and gene expression.