Researchers at the Technion-Israel Institute have directed stem cells to differentiate into neurons with the potential to repair spinal damage that causes paralysis in the legs, known as paraplegia. In an animal model, subjects suffering injury to their spinal cords, causing them to lose all mobility and feeling in their hind limbs, were treated with human stem cells cultured to differentiate into support factors that promote neural growth and survival. Three weeks after administering the stem cell treatment, 42% of the subjects began either walking or showing significant improvements in bearing weight on their hind legs. Furthermore, over 75% of the subjects responded to stimulation in their hind legs. When compared to the placebo group that received no stem cells, the results were impressive and demonstrate the immense potential of utilizing stem cells to restore the neural connections in the spine following a traumatic injury.
The Miami Project to Cure Paralysis has been working on stem cell treatments for injuries to the central nervous system. This particular treatment utilizes the application of autologous stem cells that produce the myelin sheath around neurons. Injuries to the spinal cord result in scar tissue and cavity formation at the site of injury. Given that scar tissue formation hinders signals from being transmitted to the limbs, which then become paralyzed, this treatment has been shown to create a bridge that allows the signal to be transmitted and partially restore limb function in animal subjects.
A recently published study by University of Illinois Kinesiology and Community Health Professor Marni Boppart has identified mesenchymal stem cells [MSCs] as a tool for rejuvenating muscle to prevent age-related injuries and disabilities. In addition to their ability to differentiate into other cell types, MSCs were found to secrete growth factors that stimulate the activation of the multiple cell types comprising skeletal muscle, including muscle precursor cells and satellite cells, which lose function with age.
Professor Linda Greensmith and her team of researchers from University College London and King’s College London have utilized stem cells to return muscle function to patients paralyzed by nerve damage or spinal cord injury. In a paralyzed animal model, the scientists observed transplanted stem cells growing along the injured neurons to restore motor capability to disabled muscle. Blue light pulses were then used to control the newly restored muscle movement.
Researchers at Johns Hopkins University, Department of Plastic and Reconstructive Surgery find that mesenchymal stem cells [the type of stem cells found in teeth] promoted nerve regeneration in animal models [in this case - rodents] with paralyzing leg injuries. According to the researchers, "Mesenchymal stem cells may be a promising add-on therapy to help damaged nerves regenerate.” The study found that the rodents treated with their own stem cells responded best to the treatment. Those treated with donated cells from dissimilar rodent types – a situation most similar to human transplants – rejected their new limbs.