Introduction
Stroke is the leading cause of long-term disability in the United States. Each year, more than 795,000 Americans have a stroke and approximately 130,000 die from it. Although rehabilitation therapies can help some people recover movement after stroke—a major goal of therapy is to restore lost functions within three months—current treatments cannot repair all damage that occurs after this time frame. In particular, some motor neurons (nerve cells in the brain and spinal cord) continue to degenerate for months or years after an initial injury.
Brain cells created from embryonic stem cells have successfully restored movement to paralyzed rats, even after a three-month delay after stroke.
Embryonic stem cells are pluripotent cells that can develop into any cell type within the body. They have the ability to form neurons and other brain cells, which is why they are being used to generate new brain cells (neurons). These neurons produce dopamine, a neurotransmitter that helps control movement and is depleted in patients with Parkinson’s disease.
In this study, researchers took embryonic stem cells from rats and directed them to become dopamine-producing neurons in culture dishes. The team then transplanted these newly formed neurons into rats that had suffered stroke caused by a toxin known as MPTP, which destroys dopamine-producing neurons in the brain. Three months after their strokes, these rats were able to regain control over their movements; they could balance on two legs or even walk again using a rotating rod apparatus designed for this purpose.
This research was led by scientists at the National Institute of Neurological Disorders and Stroke (NINDS), part of the National Institutes of Health. The study appears in the September 18, 2013, issue of the New England Journal of Medicine.
A study published in the New England Journal of Medicine on September 18, 2013, has found that a single injection of human embryonic stem cells (hESCs) into the brains of rats with stroke improved their ability to walk and balance as well as their overall recovery.
This research was led by scientists at the National Institute of Neurological Disorders and Stroke (NINDS), part of the National Institutes of Health. The study appears in the September 18, 2013, issue of the New England Journal of Medicine.
Researchers injected hESC-derived neural progenitor cells into rats’ brains after they had experienced an ischemic stroke or a transient focal ischemia attack (TIA). A TIA is caused by a temporary disruption in blood flow to part of your brain; it causes symptoms similar to those caused by stroke but doesn’t cause permanent damage. In both types of injury—ischemic stroke or TIAs—the depletion of oxygenated blood can lead to permanent brain damage and disability if not treated quickly enough with medication or surgery.
“This study represents an exciting advance in our efforts to repair damage caused by stroke,” said Corinne Lasmézas, MD, Ph.D., acting deputy director of NINDS and acting scientific director at the NIH Neurosciences Blueprint Program Office. “Stem cell therapies offer great hope for the treatment of neurodegenerative diseases such as stroke.”
The study, led by scientists at NIH’s National Institute of Neurological Disorders and Stroke (NINDS) with funding from the NIH Blueprint for Neuroscience Research program, showed that stem cell therapy could repair damage caused by stroke. The work was published in the New England Journal of Medicine on September 3, 2018.
The researchers studied mice who had a simulation-induced stroke and treated them with human neural progenitor cells derived from embryonic stem cells one day after the stroke occurred. After four days, they saw improvements in motor function that lasted for five months without any further treatment—a period equivalent to several years in humans.
Past research has shown that embryonic stem cells can be used to generate new brain cells (neurons) that produce dopamine, a neurotransmitter that helps control movement and is depleted in patients with Parkinson’s disease. Response is variable when these cells are transplanted into people with Parkinson’s disease, however. Scientists wanted to know whether early transplantation would more successfully restore function after injury or disease than when it is delayed.
Past research has shown that embryonic stem cells can be used to generate new brain cells (neurons) that produce dopamine, a neurotransmitter that helps control movement and is depleted in patients with Parkinson’s disease. Response is variable when these cells are transplanted into people with Parkinson’s disease, however. Scientists wanted to know whether early transplantation would more successfully restore function after injury or disease than when it is delayed.
The researchers injected human embryonic stem cells into mice with an induced stroke within 24 hours of the injury. Mice given the stem cell treatment had better outcomes than those who did not receive it, including improved motor skills and reduced tissue damage from stroke-related inflammatory responses. Five days after stroke, mice treated with embryonic stem cells also showed significant improvements over untreated mice in tests for learning and memory related to spatial orientation.
Conclusion
This study represents an exciting advance in our efforts to repair damage caused by stroke. Stem cell therapies offer great hope for the treatment of neurodegenerative diseases such as stroke.