Overly Reactivated Star-shaped Cells Cause AD
Korean researchers have found that overly reactivated star-shaped cells explain the unpredictability of Alzheimer's disease (AD).
This finding is expected to lay the groundwork for an early diagnosis of AD and the development of new treatments.
The Institute of Basic Science (IBS) announced on Nov. 17 that a joint research team led by Lee Chang-joon, a director of the IBS, and Ryu Hoon, a director of the Korea Institute for Science and Technology (KIST), found that severe reactive astrocytes destroy nerve cells and set off and deepen AD. The research results were published in Nature Neuroscience, a sister journal of Nature.
AD has been known to be a disease ignited by toxic substances such as amyloid beta in the brain. Treatments have been developed to get rid of amyloid beta, but the continued symptoms of AD after the removal of the substance have not been properly explained. Some cases showed that an increase in amyloid beta eased AD.
In addition to amyloid beta, the research team found that overly reactivated star-shaped cells, a kind of brain cell, were another cause, and explained what had not been explained before. Astrocytes are star-shaped non-nervous cells which have the largest number among cells in the brain, and serve to maintain brain constancy. When brain diseases including AD occur, the number and size of astrocytes grow and their functions change, turning them into reactive astrocytes.
The research team confirmed through a reaction control model of astrocytes that showed that mild reactive astrocytes recover naturally, while severe reactive star cells kill nerve cells and proceed with dementia, making dementia impossible to cure.
Severe reactive astrocytes release toxic substances during their activity process. In order to eliminate them, the human body makes hydrogen peroxide, a disinfectant. The more severe reactive astrocytes are generated, more hydrogen peroxide is produced, which can cause negative side effects that kill even nerve cells.