Mesenchymal Stem Cell-Based Therapy for Stroke: Current Understanding and Challenges
Stroke is a leading cause of death and disability worldwide. It occurs when the blood supply to part of the brain is cut off, either due to a blood clot (ischemic stroke) or a ruptured blood vessel (hemorrhagic stroke). When this happens, brain cells begin to die, which can lead to long-term physical and mental impairments. Traditional treatments for stroke focus on preventing further damage and managing symptoms, but researchers are now exploring a new approach: using mesenchymal stem cells (MSCs) to help repair the brain.
What Are Mesenchymal Stem Cells?
Mesenchymal stem cells are a type of stem cell that can be found in various tissues in the body, such as bone marrow, fat tissue, and even the umbilical cord. What makes MSCs special is their ability to turn into different types of cells, such as bone cells, cartilage cells, and nerve cells. This flexibility makes them a promising candidate for treating many different diseases, including stroke.
MSCs are particularly attractive for stroke therapy because they are easy to collect, grow, and manipulate in the lab. Once MSCs are injected into the body, they can travel to the site of injury, such as the brain in the case of stroke, and help repair damaged tissue.
How MSCs Help After a Stroke
After a stroke, the brain suffers from a lack of oxygen and nutrients, which causes cells to die. The area of dead cells is called the ischemic core, while the surrounding area, known as the penumbra, contains cells that are damaged but potentially salvageable. MSCs can help by traveling to the damaged brain tissue and releasing growth factors and other chemicals that reduce inflammation, protect the remaining healthy cells, and encourage new cell growth.
MSCs also promote the formation of new blood vessels, which can help restore the blood supply to the damaged areas of the brain. By improving blood flow, MSCs give the brain a better chance to heal itself and improve the patient's recovery.
Challenges in Using MSCs for Stroke Therapy
Although MSC therapy shows great promise, there are still many challenges to overcome before it can become a widely available treatment for stroke patients. One major challenge is the timing of the treatment. Studies suggest that MSCs are most effective when administered soon after the stroke, but in many cases, patients do not receive treatment until hours or even days later, which may reduce the effectiveness of the therapy.
Another challenge is the method of delivery. MSCs can be injected directly into the brain, but this is a risky procedure that is not suitable for all patients. Alternatively, MSCs can be delivered through an intravenous (IV) injection, but this method may not deliver enough cells to the brain to have a significant impact. Researchers are still trying to determine the best way to get MSCs to the brain safely and effectively.
The Future of MSC Therapy for Stroke
Despite these challenges, the potential of MSC therapy for stroke is exciting. Scientists are working to refine the treatment, exploring different ways to deliver the cells and improve their effectiveness. For example, some studies are looking at using MSC-derived exosomes, which are tiny particles released by the stem cells that contain many of the beneficial chemicals without the need for the entire cell. This could make the therapy easier to administer and reduce potential side effects.
In the future, MSC therapy could revolutionize the way stroke patients are treated. Instead of focusing solely on preventing further damage, doctors could use MSCs to help the brain heal and regenerate, leading to better long-term outcomes and improved quality of life for stroke survivors.
Citation: Li, W., Shi, L., Hu, B., Hong, Y., Zhang, H., Li, X., & Zhang, Y. (2021). Mesenchymal stem cell-based therapy for stroke: Current understanding and challenges. Frontiers in Cellular Neuroscience, 15, 628940.