Transplantation of human glial cells into murine brains: A systematic review of efficacy and safety in neurodegenerative disorders.

Abstract

Background: Neurodegenerative diseases impact millions of individuals globally. Over the years, brain research has predominantly focused on neurons, but attention is now shifting to glial cells, the brain's support cells, which play a vital role in neurodegenerative disorders. Therefore, glial cell transplantation represents a groundbreaking treatment approach for various neurodegenerative disorders, with the potential to restore neuronal function. We evaluated the evidence on the therapeutic effectiveness of human glial cell transplantation in neurodegenerative disorders. Methods: The literature review was performed in PubMed, Scopus, and Web of Science from 2000 to 2024. The authors independently reviewed the screened articles. The study outcomes on cell differentiation, long survival restoration of neuron function, and adverse outcomes were analyzed. Results: Study results highlight promising findings, including astrocytes improving motor function and slowing disease progression in neurodegenerative animal models through neurotrophic factor secretion and reduced inflammation. Similarly, microglia transplantation has demonstrated effectiveness in reducing α-synuclein toxicity in Parkinson's disease (PD), removing amyloid-β plaques in Alzheimer's disease (AD) models, and enhancing neuronal survival. Additionally, in demyelinating pathologies like multiple sclerosis (MS), oligodendrocyte transplantation promotes remyelination, restoring axonal conduction and enhancing functional outcomes. Cografting astrocytes with neuro progenitor cells significantly improved dopamine neuron engraftment and survival for at least 6 months post-transplantation. Conclusion: The transplantation of human glial cells offers promising therapeutic potential for neurodegenerative disorders, improving neuronal survival, restoring damaged circuits, and reducing disease progression.