Human cell transplantation is able to prolong survival of mice

A recently conducted study has shown that the successful transplantation of human neural stem cells has been able to provide substantial improvement in a rare hereditary neurodegenerative disease. These findings which were published in the September issue of Cell Stem Cell show that a critical enzyme which was missing from the brains of the experimented mice was provided for by the transplanted cells. This study has proved that there might be hope for those patients that are currently suffering from any types of devastating or untreatable diseases.

One type of neurodegenerative disease that is found in children is the Infantile Neuronal Ceroif Lipofuscinosis (INCL). Also known as Batten disease, INCL is formed by a deficiency of the enzyme palmitoyl protein thioesterase-1 (PPT-1) that is created by a particular gene. A deficiency of PPT1 results in an accumulation of a cellular lipid known as lipofuscin. Any accumulation of this lipofuscin can lead to visual impairment, reduced motor and cognitive skills, neuron death, seizures and also cause premature death.

Currently, it is almost impossible to get PPT1 enzymes in the brain and so intravenous enzyme treatment is not an apt solution. However, it has been conjectured that donor cells that have been transplanted would be capable of supplying the needed enzymes directly into the brain. A mouse model that is capable of exactly replicating many aspects of human disease has been created and is now being used to find whether such stem cell replacement would be beneficial or not. Led by Dr. Nobuko Uchida, a study was carried out to test this hypothesis. “We made use of nontumorigenic, normal and nongenetically modified human cells to ably deliver the enzymes into the modeled mice. We transmitted these neural stem cells as they are self renewing and provide a permanent production of any missing enzymes.” The transplanted human neural stem cells were capable of matching and delivering the required enzymes to the modeled mice, while at the same time also providing a production of PPT1 to bring about significant improvement. After the replacement therapy, the INCL infected mice showed signs of reduced loss of motor coordination, less lipofuscin and greater neuroprotection.

These findings have shown that the direct transplant of such stem cells into the brains of those that suffer from INCL might be able to provide a long lasting and continuous supply of the missing PPT1 as well as some therapeutic benefits, thereby providing a potential medical breakthrough in combating such a disease.