Possibly the most exciting use of stem cells rests on their ability to differentiate into an enormous range of healthy functioning adult cells, thereby providing a replacement source of cells to treat serious diseases. This ultimately means that virtually any disease that results in cellular and tissue destruction can potentially be treated by stem cells. Some of the conditions are particularly debilitating and these include diabetes, spinal cord injuries, retinal disease, Parkinson’s disease, heart disease and cancer.
Stem cell research into heart disease has shown some very promising results. The goal is to eventually replace all of the damaged heart tissue with healthy cells. Some of the initial research in laboratory animals such as mice has suggested that when adult stem cells derived from non-heart tissues are transplanted into a damaged heart, the cells were still able to give rise to healthy heart muscle cells. Directing stem cell differentiation is another important feature of research into heart disease. Some of the more recent studies have shown that it could be possible to guide the differentiation of embryonic stem cells into heart muscle cells.
People who are diagnosed with type I diabetes have abnormal insulin regulation. The pancreatic cells that would normally produce insulin are destroyed by the sufferer’s own immune system. Research is now suggesting that it may be feasible to control stem cell differentiation so that stem cells are guided in the laboratory to generate specialised cells capable of producing insulin. The hope is that these cells could be transplanted into diabetics, removing their need for insulin injection. Additional research is still needed to control the conditions necessary to direct cell growth, but findings thus far are positive.
Parkinson’s disease entails the destruction of cells producing a neurotransmitter called dopamine. A recent study with embryonic stem cells found that transplanted cells were able to function and release dopamine, relieving the symptoms of Parkinson’s disease. There were, however, side effects reported that were thought to correlate with a hypersensitivity to dopamine or excessive dopamine levels. Despite the side effects, the results have still been impressive and further research should provide more insight into this potential therapy.
Many people may have already heard of bone marrow transplants, which are a type of stem cell transplant that have been used for years now. This type of transplant is used for cancers such as leukaemia, where it allows the marrow to receive fresh and healthy cells, which then multiply and give rise to the different types of blood that are necessary for life. This procedure is often a life saving one for those whose marrow has been destroyed by chemotherapy and radiation. Current research is focused on overcoming the immunological challenges of cell rejection so that the success rate of a bone marrow transplant can be improved.
Spinal Cord Injuries
The potential benefit of stem cell therapy for spinal cord injuries is remarkable in that it may one day reverse what is currently an irreversible condition. Studies have found that in laboratory animal models, stem cell injections were able to positively affect motility but the results were most significant with the lowest elapsed time between the injury and the injections. The results show that a great deal more work is needed, particularly to find successful therapies for those patients who have ‘older’ spinal cord injuries. It is hoped that this research offers some hope to those who are wheelchair bound from spinal cord injuries.
Retinal diseases vary widely but the consequences can range from mild effects on vision to complete and rapid onset of blindness. Scientists have recently been able to direct the growth of photoreceptor cells from stem cells. These photoreceptor cells are necessary for vision and scientists have been able to effectively introduce them into the retina. This progress is encouraging for those who suffer from degenerative retinal diseases because there is the possibility of restoring or saving vision. It may one day even lead to a complete reversal of blindness although research still appears to have a long path ahead before this becomes a reality.
As the incidence of many serious diseases increases, the pressure similarly increases to find cures and treatment methods. Stem cells offer the potential to dramatically reduce human suffering from disease but as of yet, we are still in the relatively early stages of providing safe and successful treatment. Numerous stem cell based studies are ongoing each year and they can offer some hope for you or a loved one suffering from a major disease.