A stroke can be devastating, causing permanent brain damage with few treatment options. Now researchers may be one step closer to a cure for stroke damage after they used stem cells to heal damaged mouse brains.
The study comes from Berislav Zlokovic, M.D., Ph.D. at the University of Southern California (USC) along with other researchers, with funding from the National Institutes of Health (NIH). The researchers published the results of their study in the journal Nature Medicine August 22nd. The researchers were hoping to use promising stem cell treatments to help the brain create new neurons and heal itself after a stroke.
The researchers divided mice into groups and simulated the effects of a stroke by disrupting blood flow to part of their brain. A week later, the equivalent of several months in human years, the researchers grafted human neural stem cells onto the dead tissue in damaged areas of the brain. The researchers then infused the area with either a placebo or a compound called 3K3A-APC. Researchers had already used 3K3A-APC in a petri dish to help neural stem cells develop into neurons, but this had not yet been tested within a live animal. This compound comes from a human protein called activated protein-C (APC), which is involved in inflammation, preventing blood coagulation, maintaining blood vessels, and regulating cell death.
After a month, the researchers compared mice who had received stem cells and 3K3A-APC to mice who had only received one or the other treatment and mice that had received neither treatment. In tests of the mouse motor skills and sensory function, the researchers discovered that mice who received both treatments performed significantly better than their peers. Many more of their stem cells had survived after a month and matured into neurons, there were more connections within the nervous system called synapses, and the stem cells treated with 3K3A-APC responded more strongly to vibrations. This means the mice who received the stem cells and compound showed much more healing after their simulated stroke.
The researchers wanted to make sure the stem cells were responsible for the post-stroke improvements in the mice. To do this, the scientists tested two groups of mice for sensory and motor functions after receiving stem cell therapy combined with the compound. After administering a toxin in one group to kill the new neurons, the researchers re-tested the mice and found that the ones who lost their new neurons lost their sensory and motor improvement as well. This showed that the new neurons produced by the stem cells were the key to the post-stroke improvement.
Although the current study involved mice, the treatment shows promise for humans. The researchers say their next step is to try the stem cell and 3K3A-APC combination therapy in human stroke patients. If successful, this treatment could help these patients regain their ability to walk, talk, and other functions damaged by their stroke. Not only would this be revolutionary for reversing stroke damage, but the researchers believe the treatment could help other patients suffering neurological damage, including those with spinal cord injuries.
A stroke is caused by oxygen and nutrient deprivation in the brain after blood flow is restricted. About 800,000 people a year in the United States have a stroke, although fewer people are dying now than in past decades. Still, it is the fifth leading cause of death in the United States. Just surviving a stroke is not the end a patient’s trouble and even patients who survive their stroke can have disability from brain damage. Survivors may face paralysis and have trouble walking, they may have memory loss or problems with reasoning or judgment, they may have problems controlling their emotions, they may be unable to talk, swallowing and eating can become difficult, and these patients may be in pain. Symptoms of a stroke can include numbness or paralysis in the face or a limb; dizziness or loss of balance and coordination when walking; blurred or double vision; trouble speaking; confusion; and a sudden, severe headache. Anyone who believes they may be experiencing a stroke should seek medical attention immediately because the earlier they get treatment the better their chances of recovery.