by admin | Mar 4, 2019 | Mesenchymal Stem Cells, Osteoarthritis
Osteoarthritis is the most common form of arthritis. In fact, when people casually use the term “arthritis” or think of the arthritis of old-age, they are usually talking about osteoarthritis. People with arthritis experience many symptoms in and around the affected joints including pain and swelling. The affected joints may become unstable or “give out.” At the same time, people who suffer from osteoarthritis may not be able to move their joints fully or smoothly. Commonly people feel that their joints are “stiff.”
Early in osteoarthritis, the pain may just occur occasionally. Perhaps, the person feels sharp pain when moving a certain way. In later stages of osteoarthritis, the affected joints constantly ache, and moving the joint becomes intensely painful.
Nonsteroidal anti-inflammatory drugs or NSAIDs can help in some cases, but they become less effective as osteoarthritis becomes more severe. Often people with osteoarthritis must receive injections of anesthetics and steroids into the joints itself. Ultimately, patients often need orthopedic surgery to grind away diseased joint tissue or even replace the joint with the artificial one.
Researchers are searching for ways to reverse osteoarthritis instead of just treating the symptoms. Fortunately, stem cells may offer hope. Doctors have long known that in people with osteoarthritis, the cartilage becomes thin and breaks down. Joint cartilage lubricates the joint, acts as a shock absorber, and helps the joint move smoothly. When cartilage breaks down, the joint becomes stiff, painful, and irritated. As recent research suggests, mesenchymal stem cells may rebuild and restore joint cartilage.
Two scientists, Kristjánsson and Honsawek, recently reviewed the state of the research in this field. They identified eight clinical studies that tested mesenchymal stem cells on patients with varying degrees of osteoarthritis. The clinical trials demonstrated several intriguing findings. Most notably, mesenchymal stem cells were able to promote cartilage regeneration, reduce pain, and improve joint function. The scientists also found that the more stem cells that were injected, the better the outcome. In addition, the beneficial effect of stem cells occurred whether the cells were taken from the patient (autologous stem cells) or from young, healthy donors (allogenic stem cells).
Importantly, patients with mild to moderate osteoarthritis enjoy the greatest apparent benefit from stem cell injections. This suggests that doctors and patients should consider stem cell treatment earlier in the course of osteoarthritis before joints become too damaged and likely require surgery.
Mesenchymal stem cell injection for osteoarthritis has now been tested in at least eight clinical studies including randomized clinical trials, which are the gold standard studies for evaluating treatments in medicine. Research is ongoing and still needed but these results are strongly encouraging. They may offer, for the first time, a way for patients to reverse the changes of osteoarthritis rather than simply treating the symptoms of the disease.
Reference: Kristjánsson et al. (2017). Mesenchymal stem cells for cartilage regeneration in osteoarthritis. World Journal of Orthopedics. 2017 Sep 18; 8(9): 674–680.
by admin | Jan 27, 2019 | Exosomes, Heart Failure, Kidney Disease, Stem Cell Research, Stem Cell Therapy, Stroke, Umbilical Stem Cell
Tissue injury is common to many human diseases. Cirrhosis results in damaged, fibrotic liver tissue. Idiopathic pulmonary fibrosis and related lung diseases cause damage to lung tissue. A heart attack damages heart tissue, just as a stroke damages brain tissue. In some cases, such as minor tissue injury, the damaged tissue can repair itself. Over time, however, tissue damage becomes too great and the organ itself can fail. For example, long-standing cirrhosis can cause liver failure.
One area of active research is to find ways to protect tissue from injury or, if an injury occurs, to help the tissue repair itself before the damage becomes permanent and irreversible. Indeed, tissue repair is one of the main focuses of regenerative medicine. Likewise, one of the most promising approaches in the field of regenerative medicine is stem cell therapy. Researchers are learning that when it comes to protecting against tissue injury and promoting tissue repair, exosomes harvested from stem cells are perhaps the most attractive potential therapeutic.
Why are stem cell exosomes so promising? Exosomes are small packets of molecules that stem cells release to help the cells around them grow and flourish. While one could inject stem cells as a treatment for diseases (and they certainly do work for that purpose) it may be more effective in some cases to inject exosomes directly. So instead of relying on the stem cells to produce exosomes once they are injected into the body, stem cells can create substantial amounts of exosomes in the laboratory. Exosomes with desired properties could be concentrated and safely injected in large quantities, resulting in a potentially more potent treatment for the disease.
Indeed, researchers have shown that extracellular vesicles (exosomes and their cousins, microvesicles) can be collected from stem cells and used to treat a variety of tissue injuries in laboratory animals.
Just a few examples of this research:
- Exosomes from umbilical cord-derived mesenchymal stem cells were able to accelerate skin damage repair in rats who had suffered skin burns.
- Exosomes from the same type of stem cell protected the lungs and reduced lung blood pressure in mice with pulmonary hypertension.
- Exosomes from endothelial progenitor cells protected the kidney from damage caused by a lack of blood flow to the organ.
In this growing field of Regenerative Medicine, research is constant and building as new science evolves from stem cell studies. Researchers are closing in on the specific exosomes that may be helpful in treating human diseases caused by tissue injury.
Reference: Zhang et al. (2016). Focus on Extracellular Vesicles: Therapeutic Potential of Stem Cell-Derived Extracellular Vesicles. International Journal of Molecular Sciences. 2016 Feb; 17(2): 174.
by admin | Jan 25, 2019 | Exosomes, Stem Cell Research
Heart disease is the leading cause of death in the United States, killing over half a million people every year. Heart disease encompasses several conditions and diseases, but the most common causes of deadly heart disease are a heart attack, heart rhythm problems, and heart valve problems. In each of these cases, damaged heart tissue becomes dysfunctional and the heart cannot pump blood efficiently or effectively. To combat this deadly set of diseases, researchers are searching for ways to heal and regenerate heart tissue. Stem cells and stem cell exosomes have shown promise.
While stem cells have been used in a variety of conditions, researchers long doubted the benefit of stem cells in heart disease. The heart, it was believed, was not a “hormonal” organ and thought to be relatively unresponsive to things like cytokines and other messengers. Fortunately, new research has completely changed this viewpoint. According to Drs. Sean Davidson, Kaloyan Takov, and Derek Yellon of the Hatter Cardiovascular Institute in the United Kingdom, “Most, if not all, cells of the cardiovascular system secrete small, lipid bilayer vesicles called exosomes.” The scientists go on to say that exosomes from stem cells “have been shown to be powerfully cardioprotective” and that exosomes produced by stem cells are capable of “activating cardioprotective pathways.”
In simpler terms, the heart and blood vessels are sensitive to the beneficial effects of exosomes. Thus, if exosomes are collected from stem cells, purified and concentrated, and then reinjected into the body, they can repair heart tissue. For example, exosomes collected from mesenchymal stem cells were able to reduce the amount of damage caused by a heart attack in mouse, and improve heart recovery after the event. This could have profound implications for humans who suffer a heart attack since damaged heart tissue can lead to heart failure, heart valve problems, and heart rhythm problems.
The study of stem cells and stem cell exosomes in heart disease is a relatively new science. Clinical trials will need to be performed to determine the role of exosomes in the treatment of heart disease. However, these findings represent an exciting avenue of research in the field of cardiology and regenerative medicine.
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