A team of researchers based at the University of Connecticut’s Technology Incubation Program have published a study in Stem Cell Reports that describes a promising novel treatment avenue for multiple sclerosis involving the use of embryonic stem cells. They found that these cells not only significantly reduced disease symptoms in mouse models, but they also yielded superior results when compared with stem cells derived from adult bone marrow, raising the possibility that this technique could eventually give rise to a viable method of treatment for this debilitating disease.
Multiple sclerosis is one of the most common diseases of the central nervous system, affecting over 2.3 million individuals worldwide. It is a chronic neuroinflammatory disease that results in the loss of the fatty sheath around neurons called myelin. This insulating layer serves to ensure that information in the form of electrical impulses is transmitted efficiently along cells of the nervous system. Current MS treatments are able to offer a relief of disease symptoms, but they are not curative and side effects limit their long-term use.
Stem cells are becoming increasingly attractive as a potential method of treatment for MS, in particular mesenchymal stem/stromal cells (MSCs) due to the ability of these cells to modulate certain parts of the immune system and regenerate neuronal cells. MSCs can give rise to various different cell types belonging to our skeletal tissues such as cartilage, bone and fat. Although MSCs derived from adult tissues have shown some promising results in clinical trials, their variability in efficacy has meant that they are unsuitable as a standard therapy for MS. Furthermore, there are often issues with the quality of cells donated.
MSCs derived from embryonic stem cells, on the other hand, have greater proliferation and differentiation potential. The researchers conducting this study therefore predicted that these cells may be a more effective mode of treatment for MS than adult-derived MSCs.
To test this theory, the team used mouse models of multiple sclerosis to compare eight MSC lines derived from adult bone marrow with four cell lines derived from embryonic stem cells. They found that several of the cell lines derived from embryonic stem cells significantly improved disease status of the mice, whereas only 1 of the adult-derived lines reduced disease scores and the effect was marginal.
They also found that adult cell lines expressed high levels of an inflammatory protein called IL-6, whereas the embryonic cell lines produced significantly lower amounts. This protein, which is a type of cell signaling molecule called a cytokine, is found in elevated levels in the blood and brain tissue of MS patients and worsens disease by stimulating autoimmunity. This therefore further supports the notion that embryonic-derived MSC lines may be more useful than adult-derived cell lines.
Another advantage of using embryonic stem cells over those derived from adult tissue is that they represent a virtually unlimited supply of good quality cells, alleviating the need for the constant recruitment of healthy donors.
More work needs to be done, but the study is promising and the researchers believe that their findings may also suggest that this method could be applied to treat other autoimmune diseases such as rheumatoid arthritis and type-1 diabetes.
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