Authors: Henry E. Young, Mark O. Speight.
Parkinson disease (PD) is the second most common progressive neurodegenerative disorder that affects older adults. PD is characterized by a low level of dopamine being expressed in the striatum and a deterioration of dopaminergic neurons and associated neural networks in the substantia nigra of the midbrain. Current medical, surgical, and rehabilitative treatments for PD have long-term side effects and do not halt the progression of the disease. Stem cell therapies generating dopaminergic neurons from fetal brain tissue, human embryonic stem cells, human induced pluripotent stem cells, mesenchymal stem cells, human neural stem cells, direct reprogramming of somatic cells and direct reprogramming of stem cells by either gene editing, and/or gene transfer have elicited keen interest as to eventual therapeutics for Parkinson disease. Unfortunately, thus far, these experimental therapies have proved to
be of limited therapeutic value in clinical trials. Using a neurotoxin-induced animal model of PD, transplantation of a naïve telomerase positive pluripotent stem cell clone demonstrated reconstitution of dopaminergic neurons and associated neural networks when stereotactically injected into neurotoxin-lesioned substantia nigra pars compactum of the ventral midbrain. Two IRB-approved clinical trials in small cohort studies (n=8 & n=4), with a combined sample size of n=12, demonstrated that intranasal infusion of autologous telomerase positive totipotent cells followed by intravenous infusion of telomerase positive pluripotent stem cells and mesodermal stem cells had a positive influence on patient symptomology with Parkinson’s Disease. No adverse effects were reported by any participant or their respective caregiver for the entire combined small cohort study (n=12). Taken together as a 2021 update of this on-going clinical study, 33% (n=4) showed moderate to no benefit of telomerase positive stem cell treatment by demonstrating a continued decline in symptoms after treatment; 33% (n=4) remained in stasis after the first month after treatment; and 33% (n=4) resolved their symptoms. The results suggest that autologous telomerase positive stem cells, TSCs, PSCs, and MesoSCs, are safe and efficacious (66%) to reduce the symptoms
in participants with Parkinson’s disease.