Shedding light on the dark side of immune cells in the brain

New findings on the function of microglial cells in a malign form of Parkinson’s disease.

Immune cells in the brain are known as microglia. They have the important function of protecting the brain from pathogens or targeting damaged cells. But they also have a dark side and can damage the brain. An international team of researchers led by Universitätsklinikum Erlangen have gathered detailed findings on microglial cells and their role in a form of Parkinson’s disease called multisystem atrophy (MSA).

MSA is a neurogenerative disease that progresses rapidly and generally proves fatal within 10 years after onset. Physicians are currently unable to hinder its progress or cure the disease. Alongside typical symptoms of Parkinson’s disease such as slow movements, MSA symptoms including problems with speech and swallowing, low blood pressure or bladder weakness. MSA is a rare disease that only affects 2 in 100 patients who have Parkinson’s.

For diseases such as Parkinson’s, Alzheimer’s or multiple sclerosis, clinical researchers have found that the microglial cells, the immune cells in the brain, are activated excessively which can cause damage to the surrounding cells and tissue. Approaches in therapy are attempting to reduce the number of microglial cells to reduce this damaging effect.

An international team of neuroscientists from the Department of Molecular Neurology at Universitätsklinikum Erlangen led by Dr. Alana Hoffmann in partnership with the University of California San Diego and the National Institutes of Health (both USA) have now shown that a lower number of microglial cells can have positive and negative consequences on the development of MSA.

In a MSA mouse model, the scientists were able to reduce the number of microglial cells by blocking a specific receptor on these cells. With treatment, the mice lived longer and the onset of neurological symptoms was delayed. The scientists also discovered that motor functions such as balance and coordination were affected more significantly, as they were able to detect neurological changes in regions of the brain responsible for motor function despite the reduction of microglial cells.

In this study, researchers were able to demonstrate clearly that microglial cells have neither a primarily negative nor a primarily positive role in MSA. Therefore further investigation is needed to unravel the double-edged function of these cells with the goal of developing new long-term therapies for MSA patients.

Further information:

https://doi.org/10.1523/JNEUROSCI.0417-22.2022

Dr. Alana Hoffmann and Prof. Dr. Jürgen Winkler
Department of Molecular Neurology, Universitätsklinikum Erlangen
Phone: +49 9131 85 39324
mn-sekretariat@uk-erlangen.de