COMBINATION OF INVESTIGATIONAL CELL-BASED THERAPY AND DEEP BRAIN STIMULATION TO ALTER THE PROGRESSION OF PARKINSON’S DISEASE

Parkinson’s disease (PD) is the second most common neurodegenerative disorder and the motor symptoms are caused by progressive loss of midbrain dopamine neurons. There is no current treatment that can slow or reverse PD. Our current “DBS-Plus” clinical trial (NCT02369003) features the implantation in vivo of autologous Schwann cells (SCs) derived from a patient’s sural nerve into the substantia nigra pars compacta (SNpc) in combination with Deep Brain Stimulation (DBS) therapy for treating patients with advanced PD. The central hypothesis of our research is that transdifferentiated SCs within conditioned nerve tissue will deliver pro-regenerative factors to enhance the survival of the degenerating dopaminergic cells in the SNpc. The main goal of our studies is to determine if implantation of peripheral nerve tissue into SNpc in combination with DBS surgeries is safe, feasible, and can possibly slow the loss of the midbrain dopamine neurons. First, RNA sequencing was used to validate the repair phenotype of human sural nerve tissue two weeks after transaction injury. The transcriptomic analysis showed that 3641 genes were differentially expressed in conjunction with the upregulation of multiple neurotrophic factors and the enhancement of axonogenesis. Secondly, to study the neurobiology of the implant, we grafted human nerve implants into the dorsal striatum of athymic nude rats (called Neuro-Avatars). Immunostaining studies showed a remarkable survival of the implanted human SCs up to 6 months post-implantation in Neuro-Avatar animals. In addition, there were significant increases in the numbers of surviving human-derived cells in the Neuro-Avatar\u27s using pre-degenerated human sural nerve tissue as compared to the same sural nerve tissue that was harvested in its normal state. Finally, we studied data from 27 human subjects with PD that had received DBS plus autologous nerve-implants. The safety of the combined intervention and the progression of the motor symptoms were evaluated at baseline, 12, and 24 months using the Unified Parkinson’s Disease Rating Scale part III (UPDRS). The safety of the studies at 2 years post-implantation showed adverse events (AE’s) that were similar to those seen with standard DBS therapy. In addition, there was a significant motor improvement on the side contralateral to the tissue implantation in comparison to the ipsilateral one. Taken together, our data support that combining DBS with in vivo pre-degenerated peripheral nerve tissue containing SCs can serve as a safe and promising disease-modifying therapy to alter the progression of PD

Isolation of Cerebral Capillaries from Fresh Human Brain Tissue

Understanding blood-brain barrier function under physiological and pathophysiological conditions is critical for the development of new therapeutic strategies that hold the promise to enhance brain drug delivery, improve brain protection, and treat brain disorders. However, studying the human blood-brain barrier function is challenging. Thus, there is a critical need for appropriate models. In this regard, brain capillaries isolated from human brain tissue represent a unique tool to study barrier function as close to the human in vivo situation as possible. Here, we describe an optimized protocol to isolate capillaries from human brain tissue at a high yield and with consistent quality and purity. Capillaries are isolated from fresh human brain tissue using mechanical homogenization, density-gradient centrifugation, and filtration. After the isolation, the human brain capillaries can be used for various applications including leakage assays, live cell imaging, and immune-based assays to study protein expression and function, enzyme activity, or intracellular signaling. Isolated human brain capillaries are a unique model to elucidate the regulation of the human blood-brain barrier function. This model can provide insights into central nervous system (CNS) pathogenesis, which will help the development of therapeutic strategies for treating CNS disorders

RNA Sequencing of Human Peripheral Nerve in Response to Injury: Distinctive Analysis of the Nerve Repair Pathways

The development of regenerative therapies for central nervous system diseases can likely benefit from an understanding of the peripheral nervous system repair process, particularly in identifying potential gene pathways involved in human nerve repair. This study employed RNA sequencing (RNA-seq) technology to analyze the whole transcriptome profile of the human peripheral nerve in response to an injury. The distal sural nerve was exposed, completely transected, and a 1 to 2 cm section of nerve fascicles was collected for RNA-seq from six participants with Parkinson\u27s disease, ranging in age between 53 and 70 yr. Two weeks after the initial injury, another section of the nerve fascicles of the distal and pre-degenerated stump of the nerve was dissected and processed for RNA-seq studies. An initial analysis between the pre-lesion status and the postinjury gene expression revealed 3,641 genes that were significantly differentially expressed. In addition, the results support a clear transdifferentiation process that occurred by the end of the 2-wk postinjury. Gene ontology (GO) and hierarchical clustering were used to identify the major signaling pathways affected by the injury. In contrast to previous nonclinical studies, important changes were observed in molecular pathways related to antiapoptotic signaling, neurotrophic factor processes, cell motility, and immune cell chemotactic signaling. The results of our current study provide new insights regarding the essential interactions of different molecular pathways that drive neuronal repair and axonal regeneration in humans

Abstract Number ‐ 258: Effect of COVID‐19 Vaccination on COVID‐19 associated Stroke: A Propensity‐Matched Case‐Control Study

Introduction Coronavirus disease 2019 (COVID‐19) vaccines have demonstrated efficacy in protecting against severe respiratory distress, averting hospitalization and long‐term sequelae of COVID‐19 infection. The study aimed to determine the effect of COVID‐19 vaccination on mortality and complications due to COVID‐19 associated acute ischemic stroke (AIS). Methods Using TriNetX COVID‐19 research database, patients who had received full vaccination from December 1, 2020, to April 30, 2021, and later had AIS within 30 days of COVID‐19 infection during the period from June 1, 2021, to November 30, 2021, were identified. A control group with unvaccinated COVID‐19 patients with AIS was identified in the same study period. The two groups were matched for demographics and comorbidities with 1:1 propensity score matching. All‐cause mortality was the primary outcome while intracranial hemorrhage (ICH) and venous thromboembolism (VTE) were secondary outcomes at 30 days. Results During the study period, 21814 patients were admitted with AIS within 30 days of COVID‐19 diagnosis: 21233 patients were unvaccinated while 581 patients were vaccinated before their AIS. After propensity score matching, 581 patients in both groups were balanced for relevant characteristics. Patients fully vaccinated prior to acquiring COVID‐19‐associated AIS had lower rates of all‐cause mortality [6.9% (40/581) vs 10.7% (62/581), P = 0.02, hazard ratio = 0.62; 95% confidence interval = 0.41, 0.92)], ICH (3.1% vs 6.9%; OR 0.44, p = 0.005) and VTE (2.9% vs 7.9%; p = 0.0007) when compared with unvaccinated patients. Conclusions Within the limitations of retrospective observational study, prior vaccination for COVID‐19 is associated with improved one‐month survival and reduced complications after COVID‐19 associated AIS