Navigation Links
Alzheimers Disease Enzyme may Interfere With Brain Function

An enzyme involved in the formation of the amyloid-beta protein associated with Alzheimers disease can also alter the mechanism by which signals are transmitted between brain cells , the disruption of which can cause seizures.

These findings from researchers at the MassGeneral Institute for Neurodegenerative Disorders may explain the increased incidence of seizures in Alzheimers patients and suggest that potential treatments that block this enzyme called beta-secretase may alleviate their occurrence.

Alzheimer's disease is characterized by plaques within the brain of the toxic amyloid-beta protein. Amyloid-beta is formed when the larger amyloid precursor protein (APP) is clipped by two enzymes BACE and gamma-secretase which releases the amyloid-beta fragment.

Signaling impulses in nerve cells are transmitted via voltage-gated sodium channels, structures on the cell membrane that transmit electrochemical signal by admitting charged sodium particles into the cells interior. Sodium channels consist of an alpha subunit, which makes up the body of the channel, and one or two beta subunits that help to regulate the channels activity.

Previous studies from Kovacs team and others showed that the BACE and gamma-secretase enzymes that release amyloid-beta from APP also act on the beta2 subunit of neuronal sodium channels. The current study was designed to examine how this processing of the beta2 subunit may alter neuronal function.

Lead author Doo Yeon Kim, PhD, and colleagues first confirmed that the beta2 subunit, similar to APP, can be acted on by BACE and gamma-secretase, releasing a portion of the beta2 molecule from the cell membrane.

A series of experiments using brain tissue from animal models and from Alzheimers patients revealed the following series of cellular events: Elevated levels of the free beta2 segment within the cell appear to increase production of the alpha subunits, but those molecules are not incorporated into new sodium channels on the cell surface. The resulting deficit of membrane sodium channels inhibits the passage of neuronal signals into and through the cells.

Neuronal sodium-channel dysfunction is known to cause seizures in both mice and humans. In a supplement to the current paper the investigators present evidence that sodium channel metabolism is altered in the brains of Alzheimers patients compared with non-demented individuals of similar age.

Our study suggests that the BACE inhibitors currently being developed to reduce amyloid-beta generation in Alzheimers disease patients may also help prevent seizures by alleviating disrupted neural activity, Kovacs explains. However, complete inhibition of BACE activity could interfere with the enzymes normal regulation of sodium channels, so therapeutic strategies using those inhibitors will need to be carefully designed.


'"/>




Related medicine news :

1. Testing genes for disease does not cause harm to children of people with Alzheimers
2. Age-Dependent Alterations Not Specific For Alzheimers Disease
3. Killing two birds (cholesterol and Alzheimers disease) with the same stone
4. Exposure To High Aluminum Levels In Tap Water Lead To Rare Form Of Alzheimers
5. Sugar variant may make a world of difference to Alzheimers disease
6. Cancer Causing Protein May Heal Alzheimers
7. Emotional Stress Could Be a Factor in Causing Alzheimers: Study
8. Alzheimers Incidence is Set to Quadruple by 2050
9. GAB2-A New Alzheimers Gene Identified
10. Reduced Oxygen to the Brain Increases Alzheimers Risk in Stroke Victims
11. Magnets to the rescue of Alzheimers patients
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:6/25/2016)... ... 2016 , ... Austin residents seeking Mohs surgery services, can now turn to ... Dr. Russell Peckham for medical and surgical dermatology. , Dr. Dorsey brings specialization to ... fellowship in Mohs Micrographic Surgery completed by Dr. Dorsey was under the direction of ...
(Date:6/25/2016)... ... June 25, 2016 , ... "With 30 hand-drawn hand ... project," said Christina Austin - CEO of Pixel Film Studios. , ProHand Cartoon’s ... within Final Cut Pro X . Simply select a ProHand generator and drag ...
(Date:6/25/2016)... ... June 25, 2016 , ... As a lifelong Southern Californian, Dr. ... his M.D from the David Geffen School of Medicine at UCLA. He trained in ... to complete his fellowship in hematology/oncology at the UCLA-Olive View-Cedars Sinai program where he ...
(Date:6/25/2016)... ... 2016 , ... On Friday, June 10, Van Mitchell, Secretary of the Maryland ... iHire in recognition of their exemplary accomplishments in worksite health promotion. , The Wellness ... & Wellness Symposium at the BWI Marriott in Linthicum Heights. iHire was one of ...
(Date:6/24/2016)... ... 24, 2016 , ... A recent article published June 14 on ... article goes on to state that individuals are now more comfortable seeking to undergo ... such as calf and cheek reduction. The Los Angeles area medical group, Beverly Hills ...
Breaking Medicine News(10 mins):
(Date:6/26/2016)... 2016 Jazz Pharmaceuticals plc (Nasdaq: ... Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended ("HSR"), ... Inc. ("Celator"; Nasdaq: CPXX ) expired effective ... As previously announced on May 31, 2016, ... agreement under which Jazz Pharmaceuticals has commenced a tender ...
(Date:6/26/2016)... 26, 2016 Story Highlights: ... models within the health care industry is causing providers ... , Deloitte offers a suite of solutions for ... impacting efficient cost optimization: labor resource analysis, revenue cycle ... facilitate better outcomes and better economics ...
(Date:6/24/2016)... 2016  Collagen Matrix, Inc., ("Collagen Matrix") the ... of collagen and mineral based medical devices for ... Bill Messer has joined the company as ... the growing portfolio of oral surgery, neurosurgery, orthopaedic ... joins the Collagen Matrix executive team as an ...
Breaking Medicine Technology: