Scientists find hormonal switch of type 2 diabetes

New research has found that a hormone, contributing to a rare condition called neonatal progeroid syndromen, could be the key to prevent gaining excess weight, in mice.
Along with physical inactivity and a host of other environmental factors, obesity is one of the leading risk factors in the development of type 2 diabetes. Finding ways to prevent putting on extra weight is therefore important.
Neonatal progeroid syndromen, known as NPS, affects only a small fraction of the population and is characterised by traits including extreme thinness.
In this condition, there is an absence of the fat layer under the skin that could be the result of bad interactions with a glucose-releasing hormone, called asprosin.
Asprosin affects a part of the brain regulating appetite, and blocking it apparently counters weight gain in mice.
A study led by researchers at Baylor College of Medicine, in Texas, USA, zeroed in on the mechanism of action of asprosin.
They discovered that people with NPS had mutations in a gene (FBN1) responsible for controlling asprosi, which is secreted by fat tissue and causes the liver to make glucose.
The researchers did a lot of tests on two individuals with NPS and found that they had greatly reduced levels of asprosin in their system.
Then the team proceeded to genetically engineer a mouse that had a mutation in the FBN1 gene to see what the effects were on asprosin.
They found that the mice had less than half the levels of asprosin found in normal mice. The latter were also very lean and less susceptible to have impaired glucose tolerance or become obese – even when fed a high-calorie diet for six months.
In a separate experiment, the researchers showed that injecting a certain blocking agent – aimed at lowering asprosin – decreased food intake and reduced the body weight of obese mice.
An earlier study conducted by the authors of this paper has shown that reducing asprosin also diminishes appetite and lead to continued weight loss in obese mice.
The researchers think that asprosin stimulate neurons called agouti-related neuropeptide that increase appetite. Asprosin also decreases the activity of pro-opiomelanocortin (POMC)-positive neurons, which suppress appetite.
Overall, the findings shows that a hormone coming from fat tissue has all kinds of effects on appetite regulation and weight maintenance, and that controlling its levels might be key to prevent weight gain.
However, further research is needed to give a fuller picture and provide more information about the whole process by which asprosin can ward off weight gain.
The findings were published in the journal Nature Medicine.