Study shows stem cells may repair brain injury
According to the Centers for Disease Control and Prevention, 1.7 million people a year will suffer a traumatic brain injury.
A new stem cell study conducted by USF researchers may lead to respite for patients suffering traumatic brain injury (TBI).
In the study, partial neurological function was restored to neurologically impaired rats when adult stem cells were injected.
Dr. Cesar Borlongan said he and fellow USF researchers have targeted TBI with stem cell therapy. Borlongan is the vice chairman for research, neurosurgery and brain repair and the director of operations for the Center of Excellence for Aging and Brain Repair at USF.
“It’s not a magic bullet, it’s not a miraculous cure,” he said. “What we envision with stem cell therapy is an incremental advance. Say you’re totally bedridden, then you’re able to sit down, then have a wheelchair, then able to walk with a cane … that incremental advance, to us, is significant.”
Researchers in the study exposed lab rats, which had been catheterized to recreate symptoms of TBI, to the stem cell therapy.
The rats initially displayed behavioral deficits such as impaired motor skills and dull cognition. However, after three months, the researchers dissected the animals’ brains and discovered evidence of recovery.
“The cells we transplanted, they don’t survive very well. But what they initially do is form a bridge, a bio-bridge,” Borlongan said.
This biological bridge formed by the administered stem cells was observed transporting newly created brain cells to the site of neurological injury.
The fresh cells were not the injected stem cells; they originated from the rat’s brain, Borlongan said. In the human brain, there are minute regions, which generate immature neurons, he added.
The brain’s own cells effectively repaired the cells within the damaged site after the stem cell bridge was built between the neurogenic site and the repair site.
“The stem cells we were using were derived from clinical grade human bone marrow,” Borlongan said. “We then genetically modified them to mimic neuron cells found in rats.”
Paul Sanberg, USF senior vice president for research and innovation, said TBI can disrupt a large range of brain functions such as emotional stability, sense of identity, learning ability and memory creation and retrieval. The behavior TBI effects depend on which part of the brain is damaged.
“It’s usually not just one part of the brain that is damaged,” he said. “The entire brain works together.”
Borlongan said there was a prevailing notion suggesting the brain was unable to heal. Even leading scientists used to think neurological damage was irreversible, he said. However, he acknowledged evidence the brain may heal itself only to a certain degree.
Furthermore, Borlongan said rehabilitation in conjunction with stem cell therapy would be key to neurological recovery.
The research also suggests the window for recovery may be larger than once thought. The lab rats were not treated with the therapy until one month after receiving brain injury. Previously, neurological damage was considered chronic shortly after the time of incidence, Borlongan said.
Because of the findings, Borlongan said many people have requested administration of the therapy. However, the research is still too young and experimental to conduct ethically on human subjects, he said.
Borlongan said the public is often ill-informed about stem cell research.
“Stem cells are always associated with fetal or embryonic cells, but in our hands we can actually harvest stem cells from adult tissues,” he said.
Furthermore, researchers are now formulating a drug that will theoretically trigger bone marrow to release stem cells. The stem cells would be carried to the brain, effectively enabling a TBI patient’s body to heal itself.
If possible, this would avoid a medical complication known as graph rejection. The human body’s immune system often responds negatively to foreign cells, Borlongan said.
This research, he said, will be submitted to additional funding agencies.
“Clearly, the more we look at regenerative medicine and how it can help traumatic brain injury, as well as other injuries such as stroke, the more we will be able to design clinical trials and help these patients,” he said. “It’s a promising field for a very complicated disorder.”