Possible New Treatment Target for Alzheimer’s Identified

Highlights

Scientists used donated brains of individuals belonging to different age groups to examine the role of membrane protein aquaporin-4.
Results showed the prevalence of aquaporin-4 in older people who did not suffer from Alzheimer's as compared to those who had the disease.

A new membrane protein in the brain, known as aquaporin-4 has been examined by researchers.

This discovery may pave way for treatment and prevention of Alzheimer's disease in future.

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‘Identifying the form and function of the membrane protein aquaporin-4 will help in the development of medication needed to treat and prevent the progress of Alzheimer’s disease.’

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The study is published in the journal JAMA Neurology.

Researchers from the Oregon Health & Science University (OHSU), used brains donated for scientific research.

They discovered that among older adults who did not suffer from Alzheimer's Disease, aquaporin-4 was prevalent.

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"It suggests that aquaporin-4 might be a useful target in preventing and treating Alzheimer's disease," said senior author Jeffrey Iliff, Ph.D., an Assistant Professor in the Department of Anesthesiology and Perioperative Medicine in the OHSU School of Medicine. "However, we aren't under any illusion that if we could just fix this one thing, then we'd be able to cure Alzheimer's Disease."

Alzheimer's Disease

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Alzheimer's is a progressive, neurodegenrative disease, that is most often associated with aging. It is characterized by the formation of plaques and tangles in the brain cells. It destroys an individual's ability to reason, remember, imagine and learn.

It is the leading cause of dementia worldwide and is currently the sixth leading cause of death in the United States. Every 67 seconds, someone in the U.S is affected by this condition.

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About 44 million people worldwide are affected with Alzheimer’s disease and by 2030, this number may rise to 76 million.

One in 6 women of age 65 years has a chance of developing this condition compared to one in 11 men.

The disease has no known cure but there are treatments available for some of its symptoms.

Role of Aquaporin-4

The brain-wide network of channels is collectively known as the glymphatic system. Aquaporin-4 is a key part of this system.

The role of Aquaporin-4 is to allow cerebral-spinal fluid from outside the brain to wash away proteins such as amyloid and tau that otherwise build up within the brain.

Accumulation of these proteins are seen in people suffering from Alzheimer’s, which plays a role in destroying neurons in the brain gradually.

"This system, and the failure of the system, may be one of many things that goes wrong in people with Alzheimer's disease," Iliff said.

Examining donated brains

The study closely examined 79 brains donated through the Oregon Brain Bank, a part of the OHSU Layton Aging and Alzheimer's Disease Center.

They were divided into three groups:

People below 60 years who had no history of Alzheimer's disease
People above 60 years with a history of Alzheimer's
People above 60 years without Alzheimer's

Prevalence of aquaporin-4

Results showed that the brains of people younger than 60 years and older people without Alzheimer’s had presence of well organized aquaporin-4 protein, lining the blood vessels of the brain.

However in the brains of older people with Alzheimer's, the aquaporin-4 protein appeared disorganized.

This may explain why these brains are unable to wash away proteins like amyloid beta, which leads to their accumulation and hence disease progression.

The study concluded that future research focusing on the form or function of aquaporin-4 may ultimately lead to medication to treat or prevent Alzheimer's disease.

In addition to Iliff, co-authors included Douglas M. Zeppenfeld; Matthew Simon, J. Douglas Haswell, and Daryl D'Abreo of the OHSU Department of Anesthesiology and Perioperative Medicine; Charles Murchison, Joseph F. Quinn, M.D., and Jeffrey Kaye, M.D., of the OHSU Department of Neurology; and Marjorie R. Grafe, M.D., Ph.D., and Randall L. Woltjer, M.D., Ph.D., of the Department of Pathology.

References

Alzheimer’s Disease - (https://www.medindia.net/patients/patientinfo/alzheimers.htm)
Douglas M. Zeppenfeld et al. Association of Perivascular Localization of Aquaporin-4 With Cognition and Alzheimer Disease in Aging Brains. JAMA Neurology; (2016) doi:10.1001/jamaneurol.2016.4370

Source-Medindia