Parkinson's Disease: The Search for a Cure in Space

Parkinson’s Disease is one of the most common neurodegenerative disorders and is second only to Alzheimer’s Disease. It affects an estimated seven to ten million people worldwide, and despite the advancement of modern medicine, it has no known treatment to stop its progression. For a long time, it was believed to have been a result of environmental stimuli without genetic roles or factors.

However, in 1997, mutations in the SNCA genes was discovered. This led to the discovery of the LRRK2 on 2004 by two groups of researchers, Zimprich et al. and Paisan-Ruiz et al. These research findings both agree that additional investigative research about the LRRK2 protein may benefit not only those that have a genetic mutation in LRRK2, but also for those that have a different genetic mutation.

Recently, the Michael J. Fox Foundation has collaborated with the Center for the Advancement of Science in Space to further understand this mutation involved with LRRK2. But, to learn more about this gene, researchers need to look at the structure in detail so they can see why Parkinson's disease develops as a result, and for this, they need a different environment to enhance this sample gene. 

Leucine-Rich Repeat Kinase 2 (LRRK2) Protein

LRRK2 is identified as a protein necessary for P21-Activated Kinase 6 (PAK6) function as a regulator of neurite complexity in the brain. LRRK2 is also linked to many other brain cell processes. However, a mutation of the LRRK2 gene disrupts those processes. This leads to brain cell loss, and eventually leads to the development Parkinson’s disease. Although additional variants of the LRRK2 mutations are discovered, there are five distinct variants that are used to segregate the disease within large families. These are the R1441C, R1441G, Y1699C, G2019S, and I2020T mutations.

The following additional information about LRRK2 and its significance on the development and treatment of Parkinson’s disease is based on the article from Cold Spring Harbor Perspectives in Medicine.

This is also one of the most common mutations as it accounts for 4% of the familial Parkinson's disease population and 1% for the sporadic PD across all populations. In certain populations, like with North African Arabs and Ashkenazi Jews, it accounts for 40% of Parkinson's disease cases. In a large multinational study that involved 1045 patients with LRRK2 mutations, the LRRK2 G2019S mutation variant accounted for 28% of the patient's population at 59 years, 51% of the patient's population at 69 years, and 74% of the patient's population at 79 years.

The symptoms and disease progression of patients that are suffering from the LRRK2 mutation does not differ a lot from other mutations. This is because the majority of LRRK2 mutation carry the G2019S variant of mutation with symptoms and disease progression very similar to those that are idiopathic Parkinson's disease patients. The other four LRRK2 mutations may show different symptoms and disease progressions. However, as those cases are few, further in-depth studies are needed to come up with an exact answer.

The normal function of the LRRK2 protein is still largely unknown. It is linked to a number of diverse pathways. However, there are two significant functions that are observed. Various studies observed LRRK2 localized at the intracellular membrane structures, which  suggests that LRRK2 is responsible for membrane trafficking reactions. Because membrane trafficking occurs in the cytoskeleton, studies suggest that LRRK2 potentially plays a role in cytoskeletal dynamics.

Since the mutation of the LRRK2 contributes to both familial and sporadic Parkinson's disease. But, there still needs to be deeper understanding and additional information of the LRRK2 Biology, which will have a profound impact on finding the progression pattern of the disease and the possibility of finding a cure. This search for a cure has led researchers to many places, but recently, it has led researcher to look beyond Earth, and take a giant step to study this gene further in outer space.