Stem cells help damaged nerve regeneration
Researchers at Johns Hopkins have made a remarkable discovery that could change the future of plastic and reconstructive surgery. In their experiments on rodents, researchers have been able to regenerate damaged nerves in the leg with a specific type of stem cells found in bone marrow and fat cells.
Study leaders W.P. Andrew Lee , MD, and Gerald Brandacher, MD, said that such a discovery marks a step forward in the field of stem cells research. Such stem cells can stimulate nerve regeneration or transplantation and can minimize the need for immunosuppressive drugs. Immunosuppressive drugs are given to patients to decrease the risk of rejection it is performed a transplant from another person. John Pang, a medical student at the Johns Hopkins University School of Medicine, said the mesenchyme stem cells ( MSCs) may be a promising therapy for regenerating damaged nerves. Pang believes that they still have to learn more in this area but that researchers are stimulated by what they learned from these experiments.
Mesenchyme cells are multipotent stem cells that are capable of self-renewal and differentiation into multiple classes of cells: osteoblasts ( bone cells ), chondrocytes ( cartilage cells ), adipocytes ( fat tissue cells ), neurons and myocytes ( cells muscle tissue ). MSCs can be harvested from several places such as umbilical cord, amniotic fluid, adipose tissue; moreover recent studies showed that these cells can be harvested even from peripheral blood. What is interesting is that studies have shown that these mesenchymal cells have immunomodulatory function that is they avoid allorecognition. In other words these cells create an immunosuppressive microenvironment which reduces the risk of rejection.
MSCs are not recognized as foreign by the immune system, that is these cells do not trigger an immune response in the body. Researchers have found that these cells secrete some substances that interfere with the immune system in several ways. Now they want to make use of these properties and not only to help regeneration of damaged nerves but also to and avoid the use of immunosuppressive drugs in transplanted patients.
Researchers at Johns Hopkins have performed three types of experiments in mice to examine the potential of MSCs in nerve regeneration: mice with femoral nerves cut and repaired ; mice with hind-leg transplant from the same biological type of rat and mice transplanted from a different type. Researchers injected MSCs either directly in the sciatic nerve or directly into bloodstream. At 16 weeks, there was a significant improvement in both nerve regeneration and nerve signaling. Mice that received transplants from the same type of mice also benefited from this procedure, but those who received a transplant from different mice rejected the transplant.