A recent preliminary study suggests that measuring DNA damage in mitochondria could potentially predict the development of Parkinson's disease, a debilitating brain disorder characterized by movement difficulties, tremors, and often dementia. Early diagnosis of Parkinson's disease is challenging, which hampers the testing of experimental treatments and delays access to existing drugs that alleviate symptoms but do not halt brain cell death. The study, conducted on rodents and using tissue samples from diagnosed Parkinson's patients, proposes that detecting DNA damage in blood samples could offer a straightforward method for early disease diagnosis.

Figure 1. An Analysis of The Blood for Parkinson's Disease

Figure 1 shows Although further validation through clinical studies is required, the identified DNA damage marker joins a growing list of biomarkers associated with Parkinson's disease. This marker could contribute to accurately diagnosing whether an individual has Parkinson's or not. The research was funded by the National Institute on Aging and was published in Science Translational Medicine. If developed into a blood test, this discovery could enable earlier administration of existing treatments and facilitate the evaluation of new therapies through clinical trials. [1] This non-invasive diagnostic approach is particularly exciting as it could potentially identify Parkinson's disease before noticeable clinical symptoms emerge, aiding physicians in providing timely interventions.

Parkinson's disease is characterized by the degeneration of specific brain neurons, leading to a decrease in dopamine levels, resulting in symptoms such as muscle stiffness, balance issues, cognitive impairment, and more. The condition is influenced by both genetic and environmental factors and affects a significant number of individuals in the United States, reaching up to 1 million people.

The new diagnostic test capitalizes on the observation that Parkinson's disease often involves dysfunctional mitochondria, which are cell organelles responsible for energy production and possess their own DNA. Researchers, including neuroscientist Laurie Sanders and her team at Duke University School of Medicine, have noted indications of mitochondrial DNA (mtDNA) damage in brain tissue from certain Parkinson's patients. Other studies have detected defective mitochondria in blood cells of patients, implying that assessing mtDNA damage in blood might reflect brain-related issues.

Sanders and her collaborators have developed an innovative assay capable of gauging the level of damaged mtDNA in a blood sample. This test successfully differentiated several groups of Parkinson's patients (consisting of around 50 individuals in each group) from healthy control subjects. Additionally, they observed elevated levels of mtDNA damage in the blood of a diagnosed Parkinson's patient who possessed a rare mutated form of the LRRK2 gene, a gene associated with an increased risk of Parkinson's disease. Sanders' team had previously linked this gene mutation to mtDNA damage in brain tissue.In essence, this novel assay has the potential to serve as a diagnostic tool for Parkinson's disease by detecting mitochondrial DNA damage in blood samples, which could reflect the underlying brain-related issues associated with the disorder. However, further research and validation are necessary to confirm the test's accuracy and clinical utility.

The newly developed mtDNA test has demonstrated its ability to detect DNA damage in individuals carrying the disease-promoting variant of the LRRK2 gene, even in the absence of symptoms. This suggests that the test could potentially identify individuals at risk of developing Parkinson's disease before severe symptoms manifest, including those without the LRRK2 mutation or other known Parkinson's-related mutations.

The assay also holds promise in evaluating the effectiveness of experimental Parkinson's treatments targeting LRRK2. In laboratory experiments, the test's creators found that a compound targeting LRRK2 reduced levels of mtDNA damage in cells from Parkinson's patients and in neurons from rats with induced Parkinson's disease. Clinical testing of the compound is underway, and the assay might serve as a means to monitor its impact on patients.[2] However, the mtDNA test has been tested retrospectively using stored blood samples. For further validation, researchers need to conduct prospective trials to confirm its accuracy in early Parkinson's detection. Additionally, understanding why blocking LRRK2 seems to reduce mtDNA damage is essential to grasp the mechanism underlying the potential biomarker's significance.

Notably, the mtDNA test is not the only contender for a blood-based Parkinson's diagnostic. Another approach involves analyzing spinal fluid for a misfolded form of a neural protein called alpha-synuclein, which tends to accumulate in the brains of Parkinson's patients. These different tests could provide complementary insights into Parkinson's disease subtypes or stages, and combining them might offer a more comprehensive understanding of the condition, ultimately leading to improved treatment strategies.

References:

1. https://www.science.org/content/article/blood-test-parkinson-s-disease
2. https://www.reuters.com/business/healthcare-pharmaceuticals/blood-test-parkinsons-disease-promising-early-study-2023-08-30/

Cite this article:

Janani R (2023),An Analysis of The Blood for Parkinson's Disease?,Anatechmaz, pp.576