Your body clock determines your weight

Recently, a discovery from the Garvan Institute of medical research in Australia revealed that an important signal system in the brain controls appetite, energy consumption and body fat composition. One of the specific genes determines the bodys weight.

Evolution has preserved the neuropeptide Y (NPY) system in most organisms, which indicates that this system is very important. In this system, the mice are generally studied. However, mouse and human NPY systems are not the same.

In the human brain, the neurotransmitter NPY acts on four well-known cell surface receptors (Y1, Y2, Y4 and Y5), triggering the effect of NPY system. Y6 also plays a role in the mouse brain. Y6 is produced in a small area of the brain that regulates the biological clock and growth hormone production. The new study shows that y6 receptors have a profound effect on the body fat composition of mice.

Lead author Professor Herbert Herzog and his colleagues knocked out the y6 gene in mice for functional analysis. Studies have shown that mice lacking y6 gene are smaller and have fewer non adipose tissue in their bodies than normal mice. In addition, as mice age, knockout mice grow fatter than normal mice, especially when fed high-fat foods. In this case, the mice became obese and had metabolic problems similar to diabetes. The findings were published in cell metabolism.

Although the NPY system in humans is not exactly the same as that in mice, Herzog believes that it is not wise to ignore y6 receptors, because the development of obesity drugs mainly depends on mouse research. "Now we see that y6 receptor mediated signaling is critical to the pattern of energy consumption at different times," Herzog said.

Studies have shown that pancreatic polypeptide is closely related to y6 in mice. This is a signal of satiety, which can control the eating situation at different times. The researchers pointed out that the same amount of calories at different times had different effects on weight.

The researchers found that y6 gene is highly expressed in the suprachiasmatic nucleus of the hypothalamus, which controls the bodys circadian rhythm and closely regulates food metabolism. In addition, y6 gene can promote the high level expression of specific peptides, including vasoactive intestinal peptide (VIP), which controls the release of growth hormone.

"Pancreatic polypeptides are also highly expressed in humans, even higher than in mice. It is likely that this peptide is highly compatible with other receptors (such as Y4), which can take over the function of y6 Herzog said, "it is important that we generally use mice as research models in screening obesity drugs. Therefore, it is very important to fully understand the functions of NPY system. "

 

Cindy