APR 07, 2016 5:03 PM PDT

Managing Microglia and Treating Neurodegenerative Disease

WRITTEN BY: Kara Marker
Even when the body has reached the peak of development, there are certain regions of the brain where neurons continue to grow. In order to keep these areas neat and clean, the brain recruits immune cells uniquely designed to clear out the dead and dying cells in the brain. 

Acting as a “garbage collector” is not a new function to the body’s immune cells or to the scientists studying them. Throughout the body, macrophages are pushed by two TAM receptors, Mer and Axl, to clear out the “junk” cells that get in the way. Immune cells express Mer and Axl to get the job done.
The area of a brain lacking Mer and Axl that Salk scientists call the ‘trail of death'
 However, in a new study from the Salk Institute, published in Nature, scientists are just now realizing the “surprising extent” to which specific cellular switches are controlling a similar “garbage collection” in the brain. Microglia act just like macrophages except strictly in the central nervous system, and these cells make up ten percent of all brain cells.

Healthy microglial function is important for both regular maintenance of brain health and for repair during a state of damage. Inspired by the potential for learning more about treating neurodegenerative diseases and inflammatory diseases like Parkinson’s, scientists from the current study began mice studies to pinpoint just how Mer and Axl instigate regular trash pick-up.

When Mer and Axl were experimentally removed from mice microglial populations, scientists saw a large aggregation of dead cells, but only in areas where neurogenesis occurs. Additionally, the amount of new neuron migration to the olfactory bulb largely increased when Mer and Axl were missing.

In mice lacking the TAM gene altogether, scientists saw a 70 percent increase of new neurons in the olfactory bulb. Scientists are still unsure how, if at all, this type of mutation would impact a mouse’s sense of smell.

In addition to appearing to affect neuronal migratory tendencies, Mer and Axl seemed to be playing another role, the scientists thought. Prompted by these two TAM receptors, microglia target healthy cells in addition to the dead and damaged. Although this seems detrimental to brain health, for a normal brain this is a beneficial function, because extra cells are usually not necessary for healthy brain function. However, if a brain is anything less than healthy, as in cases of Parkinson’s disease for example, deleting any extra healthy cells would certainly make the condition worse.

In mice models of Parkinson’s disease, deleting Axl and Mer actually helped mice live longer, with Axl being indicative of tissue inflammation in cases of neurodegeneration. This discovery has scientists realizing that these TAM receptors are in fact making diseases like Parkinson’s progress faster because they are killing too many cells. 

From this discovery, it seems that the scientists from the Salk Institute are on the brink of developing a new treatment plan for neurodegenerative and inflammatory brain diseases. However, instead of inserting something that the body is lacking for healing, scientists will inhibiting a self-inflicting mechanism to treat the condition. 
 

Source: Salk Institute 
About the Author
  • I am a scientific journalist and enthusiast, especially in the realm of biomedicine. I am passionate about conveying the truth in scientific phenomena and subsequently improving health and public awareness. Sometimes scientific research needs a translator to effectively communicate the scientific jargon present in significant findings. I plan to be that translating communicator, and I hope to decrease the spread of misrepresented scientific phenomena! Check out my science blog: ScienceKara.com.
You May Also Like
MAY 04, 2020
Microbiology
MAY 04, 2020
How Soap and Hand Sanitizer Kill Viruses
The COVID-19 pandemic has spread around the world and there is still no available treatment or a vaccine. Prevention rem ...
MAY 05, 2020
Cell & Molecular Biology
MAY 05, 2020
Preprint Suggests Sars-CoV-2 Mutation Makes it More Transmissable
Samples obtained from patients from all over the world have been used to sequence the genomes of the viral strains infec ...
MAY 25, 2020
Microbiology
MAY 25, 2020
Assessing the Risk of COVID-19 Posed by Various Summer Activities
While we know a lot more about the pandemic virus SARS-CoV-2 and the illness it causes, COVID-19, there are still many u ...
MAY 25, 2020
Drug Discovery & Development
MAY 25, 2020
Potential Targets for Alcohol Induced Liver Disease
Alcohol-related liver disease (ALD) is a fatal condition targeting more than 150 million people. Part of what makes it d ...
MAY 29, 2020
Cannabis Sciences
MAY 29, 2020
Japanese Company Makes CBD from Orange Peels
Japanese company, Hiro International, has derived cannabidiol (CBD) oil from orange peels. Free from tetrahydrocannabino ...
JUN 01, 2020
Neuroscience
JUN 01, 2020
What Causes 'Good' and 'Bad' Trips in the Brain
People who use psychedelics like magic mushrooms, LSD and DMT often describe a feeling of going 'beyond their human ...
Loading Comments...