Intrastriatal implantation of fibroblasts genetically engineered to produce brain-derived neurotrophic factor prevents degeneration of dopaminergic neurons in a rat model of Parkinson's disease.

Parkinson's disease (PD) is a neurodegenerative disorder characterized by a progressive loss of the dopaminergic neurons of the substantia nigra pars compacta (SNpc). Although various treatments are successfully used to alleviate the symptoms of PD, none of them prevents or halts the neurodegenerative process of the disease. Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family of proteins, supports the survival and the differentiation of dopaminergic neurons. BDNF also prevents the death of dopaminergic neurons in vitro, which suggests that it may be of possible use in the development of neuroprotective therapies for PD. To determine whether BDNF is neuroprotective for SNpc dopaminergic neurons in the adult brain, we used a rat model of PD in which degeneration of 60-70% of these neurons was induced by an intrastriatal injection of 6-hydroxydopamine (6-OHDA). We report here that intrastriatal grafts of fibroblasts genetically engineered to produce BDNF partially prevent the loss of nerve terminals and completely prevent the loss of cell bodies of the nigrostriatal dopaminergic pathway that is induced by the intrastriatal injection of 6-OHDA. In contrast, the implantation of control fibroblasts that did not produce BDNF failed to protect nerve terminals and cell bodies against 6-OHDA-induced damage. Our observation that grafts of BDNF-producing fibroblasts protect against 6-OHDA-induced degeneration of SNpc dopaminergic neurons in the adult rat brain opens new perspectives for treatments aimed at the prevention of neurodegeneration in PD, using gene therapy and neurotrophic factors such as BDNF

COVID-19 Vaccination for Persons with Parkinson's Disease: Light at the End of the Tunnel?

Several COVID-19 vaccines have recently been approved for emergency use according to governmental immunization programs. The arrival of these vaccines has created hope for people with Parkinson's disease (PD), as this can help to mitigate their risk of becoming infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which can lead to serious, life-threatening disease, at least among those with more advanced PD. However, both persons with PD and physicians looking after these individuals have expressed concerns about the vaccine's efficacy and safety in the specific context of PD and its symptomatic treatment. Here, we discuss our perspective on these concerns, based on our interpretation of the literature plus the unfolding experience with widespread vaccination in the population at large. Because the benefits and risks of COVID-19 vaccines do not appear to be different than in the general population, we recommend COVID-19 vaccination with approved vaccines to persons with PD, unless there is a specific contraindication. Some caution seems warranted in very frail and terminally ill elderly persons with PD living in long-term care facilities