Researchers use stem cells to understand traumatic brain injury
John D. Finan, PhD, didn’t intend to build a career out of manipulating stem cells. Far from it, in fact. As a PhD candidate at Duke University, he leaned on his mechanical engineering background to focus on creating a safer bicycle helmet to prevent head injuries.
Finan quickly realized, though, that the reason bicycle helmets hadn’t changed for years is because there isn’t much more that can be done to make them safer.
“I got disillusioned with that problem,” he says. Instead, he decided to combine his passions for engineering and biology to study stem cells as a way to learn about — and hopefully treat — traumatic brain injury (TBI).
What is TBI?
TBI results from a bump, blow or jolt to the head or body, or a penetrating head injury. Mild TBI, such as a concussion, can cause temporary brain dysfunction. Severe TBI can cause cognitive impairment, physical problems and even death.
In 2013, approximately 2.5 million U.S. emergency room visits were related to TBI. The condition is also the cause of nearly one-third of all injury-related deaths, according to the Centers for Disease Control and Prevention.
Each instance of TBI is different, because genetic makeup impacts an individual’s response. One person can shake off a head collision, while others slip into a downward spiral. As a result, treatments have been elusive.
Part of the challenge comes from the sheer complexity of the human brain. With TBI, the impact is far more than just a bruise on the body. There could be bleeding on the brain, a breach of the blood-brain barrier, dysfunction of hormone glands and so on.
It’s hard to learn about TBI because the condition cannot be diagnosed before damage occurs.
Treatment of traumatic brain injury is as complicated a problem as you could ever wish for.
“By the time somebody gets to us, a lot of the damage is already done,” says John A. Kessler, MD, neurologist and stem cell researcher at Northwestern Memorial Hospital. “That means our focus has to be repair.”
Kessler, who has spent more than 25 years investigating stem cell biology and approaches to regenerate damaged or diseased nervous systems, isn’t sure researchers will ever be able to fully re-create TBI in order to study it. However, he sees enormous potential to use stem cells to look at individual components of the condition.
And that is exactly what Finan and his team of researchers are trying to do.
The power of stem cells
Finan and his colleagues in the Department of Neurosurgery at NorthShore University HealthSystem have reproduced a small component of TBI in a petri dish. They are mimicking the trauma of TBI by stretching human neurons derived from stem cells. The goal is to pinpoint exactly what happens to cells during and immediately after TBI.
“What we’re doing is trying to extract one little piece, then add in some of the other pieces to try to understand how each piece influences the other,” Finan says.
“Treatment of TBI is as complicated a problem as you could ever wish for,” Finan says. “I’m trying to get as close as possible to traumatizing your brain without actually harming you.”
Finan starts with stem-cell-derived human neurons and stretches them to injure them, similar to the injury of TBI. His goal is to test how different drugs impact the injured neurons. It’s a process he calls brute force. He and his team will churn through drugs to see what, if anything, helps the neurons and is worthy of a clinical trial.
Finan and his colleagues are the first people to replicate trauma in neurons derived from human stem cells.
The team is also the first to stretch human neurons using this particular cell — a cell that has already been used to re-create aspects of Alzheimer’s and Parkinson’s disease. While a cure for TBI is not likely to appear quickly,
Finan isn’t discouraged.
“We now have a way to look at and understand human cells in a way we never had before,” Finan says. “It’d be irresponsible to shy away from that just because it seems like hard work.”
Stem cells are not a cure-all, Kessler says. But they can help the future of medical research and practice.
“Stem cell research is going to change the way we practice medicine,” Kessler says. “At the present time, all we can really do is treat symptoms and hope the body can cure itself. What stem cell medicine will allow us to do is actually repair the damaged body.”