Parkinsonism: Transplanted stem cells survive and thrive

Remediation of Parkinson’s via stem cell transplantation has been verified and dopamine transporter (DAT) expression was found to be normal not just in short-term studies, but for 4-14 years after transplantation of dopamine neurons, according to a study published June 5 in Cell Reports.

Researchers including Penelope J. Hallett, PhD, instructor of psychiatry and director of the In Vivo Programs and Neuroregeneration Institute at Harvard Medical School in Cambridge, Mass., and colleagues found only healthy mitochondrial localization after the placement of fetal ventral mesencephalic grafts of human dopamine neurons, which were found to be viable in the long-term.

“To determine the long-term health and function of transplanted dopamine neurons in Parkinson’s disease (PD) patients, the expression of [DAT] and mitochondrial morphology were examined in human fetal midbrain cellular transplants,” wrote Hallett et al. “DAT was robustly expressed in transplanted dopamine neuron terminals in the reinnervated host putamen and caudate for at least 14 years after transplantation.”

Transplanted neurons in five human subjects showed absolutely no sign of atrophy at any point upon immunofluorescence staining for DAT with a monoclonal antibody agent. Pathology that was found in the mitochondrial localization of dopaminergic neurons in the substantia nigra was not found in the new grafts.

“These findings are critically important for the rational development of stem-cell-based dopamine neuronal replacement therapies for PD,” the researchers wrote.