Parkinson‘s disease: genetic defect triggers multiple damages in neurons

14-Jul-2014 - Germany

People whose genome carries certain variations have a particularly high risk of developing Parkinson's disease. In particular, genetic variants in a gene referred to as GBA1 (glucocerebrosidase) are associated to an increased risk for Parkinson’s. Researchers of the German Center for Neurodegenerative Diseases (DZNE) and the Hertie Institute for Clinical Brain Research have now pinpointed the consequences that genetic variations in GBA1 have on neurons – consequences that had been largely undetermined to date.

Using stem cells, they found that mutations affecting GBA1 impair calcium metabolism and the cell’s “garbage disposal” that normally digests and recycles defective substances including alpha-synuclein, the protein that accumulates in the brain of patients suffering from Parkinson’s. This research shows a link between alterations in the GBA1 gene and cellular dysfunctions in Parkinson’s disease for the first time. It also suggests potential targets for drugs and biomarkers that could be useful for diagnosis. The study is published in the journal Nature Communications.

In people suffering from Parkinson’s, brain cells that are supposed to produce a neurotransmitter called dopamine, die off over time, making it difficult for these patients to control their movements. They may also suffer from insomnia and depression. And as the illness progresses, they may also develop dementia. To date, there is no cure for Parkinson’s disease and the actual triggers of the death of neurons, i.e. of the so-called neurodegeneration, are still unknown. However, mutations of a certain gene referred to as GBA1, have been identified as a major risk factor. “This gene contains the blueprint of an enzyme, called glucocerebrosidase, that is involved in the processing of certain lipids,” explains DZNE researcher Michela Deleidi, who also works at the Hertie Institute for Clinical Brain Research. “Alterations in this gene do not necessarily lead to Parkinson’s. In fact, whereas people with mutations in both copies of the gene are affected by a metabolic disorder called Gaucher’s disease, both Gaucher’s disease patients and individuals with a mutation in just one copy of the gene are predisposed to develop Parkinson’s.”

Up to now, the consequences these mutations have on nerve cells were largely unexplored. “Studies addressing the effect of these mutations in Parkinson’s disease have not been performed yet,” observes Deleidi. She therefore set out to elucidate the consequences of the genetic mutations. The study involved a team based in Tübingen including Professor Thomas Gasser, as well researchers in Italy and the United States.

Original publication

David C. Schöndorf, Massimo Aureli, Fiona E. McAllister, Christopher J. Hindley, Florian Mayer, Benjamin Schmid, S. Pablo Sardi, et al.; “iPSC-derived neurons from GBA1-associated Parkinson’s disease patients show autophagic defects and impaired calcium homeostasis”; Nature Communications, 2014.

https://www.bionity.com/en/news/149063/parkinsons-disease-genetic-defect-triggers-multiple-damages-in-neurons.html