Specific protein may cause obesity by interfering with brown fat

124

NOT all body fat is bad news – in fact, the so-called brown and beige fat fulfill important metabolic functions, producing energy and helping the body to adjust to cold temperatures. New research finds that high levels of a certain protein may increase obesity by suppressing the energy-producing action of brown and beige fat.
New research suggests that targeting the Id1 protein may help to reverse obesity by increasing levels of brown fat and reducing white fat, which is commonly found on the belly.
Our bodies store energy in the form of fat. The fat, or adipose, tissue – which helps to regulate the body’s metabolism – is typically divided into two main types: white and brown. Additionally, a third type of fat can develop from white fat, as “beige” cells can form there when activated by certain stimuli.
White and brown fat have different functions. White fat mainly stores energy in the form of triglycerides – a type of fat commonly found in the blood, which may trigger conditions such as heart disease and diabetes if abnormally high. Brown fat, on the other hand, specializes in expending that energy by creating heat during exposure to cold temperatures, in a process known as thermogenesis.
There are also structural differences between these types of fat. Brown and beige fat have more mitochondria, which are also known as the “powerhouses” of the cell because they turn food into energy. White fat, on the other hand, has fewer mitochondria and blood vessels.
Brown and beige fat are considered “healthier” than white fat. Previous research has suggested that brown and beige fat reduce metabolic diseases and obesity in mice, and studies in humans have revealed a connection between leanness and these types of fat.
New research – published in the journal Diabetes – shows that high levels of a certain protein diminishes the positive, energy-producing effects of brown and beige fat.
The corresponding author of the study is Dr. Satya Ande, a molecular biologist at the Georgia Cancer Center and Medical College of Georgia at Augusta University.
The protein is called Id1, and previous research has connected it with prostate cancer. In their study, Ande and colleagues genetically modified mice to produce excessive levels of Id1 in their fat cells. They then fed these mice a high-fat diet, as well as a regular diet. They also fed a control group of normal mice the same diets.