Fat ‘disrupts sugar sensors causing type 2 diabetes’
20 August BBC
US researchers say they have identified how a high-fat diet can
trigger type 2 diabetes, in experiments on mice and human tissue.
Writing in the journal Nature Medicine, they say that fat interferes
with the body’s sugar sensors.
The authors argue that a deeper understanding of the processes
involved could help them develop a cure.
Diabetes UK said the study was interesting and a “theory worth
investigating further”.
One of the main risk factors for type 2 diabetes is being overweight
- rising obesity levels have contributed to a doubling of diabetes cases
in the last 30 years.
Fat and sugar Sugar in the blood is monitored by pancreatic beta
cells.
If sugar levels are too high then the cells release the hormone
insulin, which tells the body to bring the levels back down.
Key to this is the enzyme GnT-4a. It allows the cells to absorb
glucose and therefore know how much is in the blood.
Researchers at the University of California and the Sanford-Burnham
Medical Research Institute say they have shown how fat disrupts the
enzyme’s production.
Experiments on mice showed that those on a high-fat diet had elevated
levels of free fatty acids in the blood.
These fatty acids interfered with two proteins - FOXA2 and HNF1A -
involved in the production of GnT-4a.
The result: fat effectively blinded cells to sugar levels in the
blood and the mice showed several symptoms of type 2 diabetes.
The same process also took place in samples of human pancreatic
cells.
Lead researcher Dr Jamey Marth said: “The observation that beta cell
malfunction significantly contributes to multiple disease signs,
including insulin resistance, was unexpected.”
He suggested that boosting GnT-4a levels could prevent the onset of
type 2 diabetes: “The identification of the molecular players in this
pathway to diabetes suggests new therapeutic targets and approaches
towards developing an effective preventative or perhaps curative
treatment.
“This may be accomplished by beta cell gene therapy or by drugs that
interfere with this pathway in order to maintain normal beta cell
function.”
Dr Iain Frame, Director of Research at Diabetes UK, said: “This is a
well-executed study into possible factors responsible for the events
that lead to type 2 diabetes.
“The researchers have linked their results in mice to the same
pathways in humans and although they did not show they could prevent or
cure type 2 diabetes they have shown it is a theory worth investigating
further.
“We will watch this with great interest and hope this early work will
eventually lead to some benefit to people with type 2 diabetes.”
|