Dr. Yoon-Seong Kim has been studying Parkinson’s disease for nearly two decades, trying to figure out why a particular protein is found at higher levels in the brain cells of patients.
He may be closer to some answers.
He and three of the scientists in his lab at UCF’s Burnett School of Biomedical Sciences have successfully used a cutting-edge technology to develop a tool that monitors in real time the activity of a gene that produces the protein alpha-synueclein.
The new method, published in the journal Scientific Reports in April, is a step toward understanding the disease and finding potential treatments for it. But it’s even more exciting for the local scientists, because it makes them one of the first research teams at UCF to publish a study involving the use of game-changing gene-editing technology called the CRISPR method.
CRISPR was first discovered in the immune system of bacteria as a defense mechanism against viruses. By 2013, researchers showed that the system can be used in animal and human cells to target specific stretches of DNA at precise locations to modify genes.
The CRISPR system is guided by short RNA sequences and binds to the matching sequence, usually a piece that codes for a specific gene, in the animal or human DNA. It then cuts the sequence, hence modifying, turning on or turning off the target gene.
“We started discussing different ideas and in 2015 we figured this tool can help us do our research and contribute to the Parkinson’s field,” said doctoral student Sambuddha Basu.
Parkinson’s is a progressive and chronic movement disorder that affects nearly 1 million people in the United States. There are an estimated 60,000 new diagnoses each year.
It’s not clear what causes Parkinson’s, which is one of the reasons that there are no drugs available today that can stop or reverse it. Patients are prescribed medications that target their symptoms, mostly by helping adjust the dopamine levels, which drop as a result of cell death.
But to effectively fight the disease, “we want to stop that [cell] degeneration or reduce the rate of degeneration,” said Kim.
To get to that stage, scientists need to find the cause, and alpha-synuclein, the protein that Kim has been studying, is considered to be one of the culprits.
Researchers know that in patients with Parkinson’s the levels of alpha-synuclein protein are much higher in the brain cells. The protein turns toxic as it aggregates within the cells and eventually kills the neurons.
In less than 10 percent of the population, including some individuals who develop Parkinson’s at a young age, a genetic mutation is to blame. But absent a mutation, scientists don’t know why the gene starts producing more alpha-synuclein than it’s supposed to and why the protein aggretates they way it does.
“The theory is that if you just inhibit the [protein’s] aggregation, then we can reduce the toxicity of this protein and maybe prevent the degeneration of [neurons],” said Kim.
Once equipped with the CRISPR gene-editing technology, the team decided to use it to shed some light on the gene’s activity. Literally.
They inserted a luminescent tag beside the gene that codes for alpha-synuclein gene, making the resulting protein luminescent.
“In this system, you grow the cells, you treat them and within 10-15 minutes you get your data,” said Dr. Subhrangshu Guhathakurta, a scientist at Kim’s lab.
Researchers can introduce different compounds and stressors to the cells to see how the gene responds. The more proteins the gene produces, the brighter the area.
“We also want to see if we can make use of any drug to lower that high light production,” said Basu.
Lighting up the genes and their products with luminescent tags is not new in research, but UCF scientists say they’re one of the first to use a specific luminescent tag with the alpha-synuclein gene.
“This approach is promising and interesting,” said Dr. Vikram Khurana, principle investigator and associate neurologist at Ann Romney Center for Neurologic Diseases at Brigham and Women’s Hospital and Harvard Medical School in Boston.
“But I think the idea that we have new methods afforded to us by CRISPR is really the story. This is a great example of how CRISPR can potentially impact diseases that have been difficult to find therapies for,” said Khurana, who’s not involved with Kim’s research.
Kim’s studies are still several years away from potentially resulting in a drug that treats Parkinson’s.
The team still has to test its new method in neurons. They’ve been using kidney cells, which are easier to work with.
Next they have to screen and pick out a handful of chemical compounds that have the desired impact on their target gene. A few of those drug candidates are then tested in animals, and if one proves non-toxic and effective, human clinical trials begin.