ALZEIMER ..DIABETES BRAIN??

[maria angelica sassone]

30/10/2009 - BBC Science

That's the conclusion of a team of scientists will now try to test whether the hormone insulin, or drugs to improve their production, could help patients suffering from Alzheimer's.

The research, published in Proceedings of the National Academy of Sciences (PNAS)(Proceedings of the National Academy of Sciences, USA) was carried out by scientists at Northwestern University in Chicago, and the University of Rio de Janeiro, Brazil.

Experts say the finding could lead to new treatments for disease.

"What we found was that insulin may have a protective effect on neurons," the BBC said Dr. William Klein, Northwestern University in Chicago, who led the study.

"The protection against toxic damage of a protein that causes memory loss in Alzheimer's disease," says the researcher.

Type 3 Diabetes

The relationship between insulin and brain damage has been investigated since scientists found evidence that insulin is active in the brain.

The new study, explains Dr. Klein, analyzed the effects of insulin on a group of proteins called ADDLs (amyloid-derived diffusible ligands beta), which form plaques in the brains of Alzheimer's patients and cause damage.

 

Recognize Alzheimer's disease is a brain type of diabetes may lead to new discoveries to treatments for this devastating disorder Prof. Sergio Ferreira

Scientists took neurons from the hippocampus, a part of the brain that plays a fundamental role in memory.

 

Neurons tested in the insulin and a drug called rosiglitazone (Avandia) given to patients with type 2 diabetes to increase the effect of the hormone in the cells.

Later, when neurons were exposed to the ADDL they were less susceptible to damage.

This means, scientists say, that insulin is able to block the effects of this toxic protein.

"A year ago we began to investigate the effect of insulin in the brain," says Dr. Klein. "That's when we realized that these toxic substances that cause Alzheimer neurons were resistant to insulin."

"And essentially this is a Type 3 diabetes, in which the brain becomes resistant to this hormone signals," says the researcher.

Dr. Klein believes that a drug to improve the brain's sensitivity to insulin may lead to a new way to treat Alzheimer's disease.

Scientists believe toxins in the attack ADDLs to neurons in very specific ways.

That is, just come to adhere to very specific sites of neurons and once attached cause damage to the synapses (the communication process) between neurons.

"The thing about insulin is that it can dramatically decrease the bonding capability of ADDL toxins in neurons," says Dr. Klein.

 

New drugs

 

Perhaps you could develop a drug against Alzheimer's based on insulin.

The investigation is in its early stages, but scientists believe that perhaps in the future could develop a new treatment based on insulin combined with drugs that enhance further the role of this hormone.

 

According to Dr. Klein, "Our study showed that if you have low levels of insulin neurons are not well protected."

"But if we add to a drug like Avandia insulin, the hormone becomes a much stronger ability to block the toxins."

Another of the study's authors, Professor Sergio Ferreira of the University of Rio de Janeiro, said, "recognize that Alzheimer's disease is a brain type of diabetes may lead to new discoveries to treatments for this devastating disorder."

In fact, scientists know that people with diabetes have an increased risk of developing Alzheimer's disease and that insulin affects how the brain works.

But the research, experts say, offers new evidence that may be possible to treat the disease as a form of cerebral diabetes.

"I think it's a very exciting find," says Dr. Klein, and several laboratories and are currently pursuing this line of research. "