Team:NYC B1O/Description
Project Description
WHAT is Parkinsons?
Parkinson’s Disease (PD) is a neurodegenerative disorder that breaks down the central nervous system in the substantia nigra part of the brain. As a main source of dopamine, degeneration of this section is one of the primary reasons for the development of the symptoms over the years. Some of the symptoms include:
- Slowness of movement and stiffness (Bradykinesia)
- Tremors
- Restless sleep
- Difficulty Speaking
- Amnesia
WHY is it a problem?
Currently, the treatments for Parkinson’s only delay the development of the disease and it is time to use synthetic biology to reverse the effects from its root cause. Research has found that alpha-synuclein, a protein involved in brain functioning is misfolded in Parkinson’s patients that leads to neurodegeneration. Once misfolded, the protein aggregates the neurons, and currently, researchers are unsure if the aggregations cause the eventual neurodegeneration or the misfolding itself.
WHO are affected?
Although Parkinson’s, by itself, does not lead directly to morality, its symptoms are grave and potentially life threatening. Complications from Parkinson’s, according to the CDC, are the 14th leading cause of death in America. Over 65,000 people in the United States are diagnosed with Parkinson’s each year, amounting to nearly one million total. This fatality rate has doubled since the late 1990’s, despite advances in biotechnology and medicine. With the average age of the population growing older each year, the threat from Parkinson’s and other neurodegenerative diseases will only compound.
HOW are we tackling it?
Our solution, Project Refold, tackles this problem from both ends; eliminating the risk of misfolding completely by attaching chaperons (a naturally occurring helper protein) and an autophagy tag that marks the misfolded protein for either refolding or destruction.
Rationale and Background:
As of 2020, nearly a million Americans are diagnosed with Parkinson’s, with this number increasing by sixty-five thousand every year. Parkinson’s Disease (PD) is a neurodegenerative disorder that results in the breakdown of the central nervous system and affects the human motor system. As the second-most common neurodegenerative disease, Parkinson’s disease makes life extremely difficult for people who suffer from it impairs movement and even cognitive functions. However, there is still no form of cure for this disease. To improve the lives of those who suffer from this disease, our goal is to help in the effort of finding a cure, restoring them to the normal lives that they once had. Currently, the treatments for Parkinson’s are temporary and solely serve to improve quality of life. Thus, our team decided to use synthetic biology to prevent and reverse the effects of PD by treating its root cause. Our solution, Project Refold, is focused on one certain aspect of Parkinson’s: alpha-synuclein. Research has found that alpha-synuclein, a protein involved in brain functioning, is misfolded in Parkinson’s patients, leading to neurodegeneration (Stefanis 2012). Once misfolded, the protein aggregates in the neurons, and currently, researchers are unsure if the aggregations cause neurodegeneration or the misfolding itself.
Literature Review:
Alpha-synuclein and its Effect in PD 𝛼-Synuclein (𝛼-syn) has been found to be linked to Parkinson’s Disease (PD) after the finding of point mutations in SNCA, the gene encoding 𝛼-syn, in common PD forms. (Dehay et al., 2015) A53T is the first point mutation on the SNCA gene on chromosome 4q21-q23 that causes autosomal-dominant PD. (Dehay et al., 2015) α-syn needs to have the proper shape and function in order to keep the nervous system healthy. Normal soluble α-syn is degraded by the ubiquitin-proteasome system while complex forms are disposed of by the autophagy/lysosomal pathway, ALP. More and more research is showing that α-syn may self-propagate, which can prolong the effects of PD on a patient. (Dehay et al., 2015) Our research team has built on top of this and is working on targeting α-syn since its mutated form is the root of Parkinson’s Disease. Action of HSP70 The question that our research team worked on was “what do we need to use in order to work with α-syn?” The team decided on 2 ways of treating the irregular α-syn. One of these methods is to use HSP70, a molecular chaperone that prevents the formation of aggregates and increases their reduction and clearance. (Opazo et al., 2008) The overexpression of Hsp70 reduced the oligomerization of α-syn by ~50%. (Outeiro et al., 2008) Cells expressing Hsp70 demonstrated a reduced level of cytotoxicity. (Outeiro et al., 2008) HSP70 is a significant chaperone that will help our team fix the irregular forms of α-syn by allowing us to take advantage of its ability to reduce aggregates and cytotoxicity. Autophagy and 𝛼-syn Clearance The other method of treating the irregular α-syn is through autophagy and α-syn clearance. This method involves degrading the affected α-syn. Autophagy is a lysosomal degradation pathway that has been conserved through evolution. (Feng et al, 2014) Autophagy could be used to degrade the affected α-syn. Aggregate-prone proteins are more efficiently cleared by autophagy than other tested methods. (Webb et al., 2003) When autophagy was inhibited, the levels of α-syn increased, proving its link. (Webb et al., 2003) It was proven that autophagy inducer rapamycin increases the clearance of all forms of α-syn. (Webb et al., 2003) Our team has used autophagy in our research and worked around the fact that α-syn could be cleared, meaning the affected α-syn that causes PD could be removed to stop its effect on the nervous system. Identification and proof-of-concept of autophagy tags A key part of the autophagy process is the autophagosome. These molecules contain the material that will be degraded by the lysosomes. However, we need sensors to monitor the autophagosomes if we want to clear the affected α-syn. One research project has developed new sensors that are efficient for autophagosomes. In that research, endogenous LC3/GABARAP proteins were detected at the autophagosome using an LC3‐interacting region (LIR) and a short hydrophobic domain (HyD). (Lee et al., 2017) Out of the sensors harboring the LIR motifs in 34 LC3-binding proteins, HyD‐LIR(TP)‐GFP, with the LIR motif from TP53INP2, detected all LC3/GABARAPs‐positive autophagosomes. (Lee et al., 2017) HyD‐LIR(Fy)‐GFP, with the LIR motif from FYCO1, precisely detected LC3A/B‐positive autophagosomes. (Lee et al., 2017) Our research team found potential in these sensors and have incorporated them into our research to treat α-syn.
Goals:
The goal of Project Refoldis to develop an in vitro cure for Parkinson’s disease by breaking up the plaques responsible for the symptoms of PD through the use of chaperon and autophagy tag based constructs. In doing this, our team would successfully learn and apply the laboratory techniques required to create our solution and be able to apply this knowledge to future research. Our solution tackles this problem from both ends: eliminating the risk of misfolding completely by attaching chaperons (a naturally occurring helper protein) and an autophagy tag that marks the misfolded protein for either refolding or destruction.
Work Cited
Dehay, Benjamin et al. “Targeting α-synuclein for treatment of Parkinson's disease: mechanistic and therapeutic considerations.” The Lancet. Neurology vol. 14,8 (2015): 855-866. doi:10.1016/S1474-4422(15)00006-X Feng, Yuchen et al. “The machinery of macroautophagy.” Cell research vol. 24,1 (2014): 24-41. doi:10.1038/cr.2013.168 Lee YK, Jun YW, Choi HE, et al. Development of LC3/GABARAP sensors containing a LIR and a hydrophobic domain to monitor autophagy. EMBO J. 2017;36(8):1100-1116. doi:10.15252/embj.201696315 Opazo, Felipe et al. “Accumulation and clearance of alpha-synuclein aggregates demonstrated by time-lapse imaging.” Journal of neurochemistry vol. 106,2 (2008): 529-40. doi:10.1111/j.1471-4159.2008.05407.x Outeiro, Tiago Fleming et al. “Formation of toxic oligomeric alpha-synuclein species in living cells.” PloS one vol. 3,4 e1867. 2 Apr. 2008, doi:10.1371/journal.pone.0001867 Webb, Julie L et al. “Alpha-Synuclein is degraded by both autophagy and the proteasome.” The Journal of biological chemistry vol. 278,27 (2003): 25009-13. doi:10.1074/jbc.M300227200