Mesenchymal stem cell therapies for neurodegenerative diseases: Advancements, challenges, and opportunities.

Neurodegenerative diseases, including multiple sclerosis, amyotrophic lateral sclerosis, Huntington's disease, retinal degenerative diseases, Alzheimer's disease, and Parkinson's disease, continue to pose a significant clinical challenge due to the progressive loss of neural tissue structure and function. Stem cell-based therapies are gaining attention for the treatment of neurodegenerative diseases. Mesenchymal stem cells, particularly those derived from perinatal tissues, exhibit remarkable plasticity, along with immunomodulatory, neurotrophic, and regenerative capabilities. Mesenchymal stem cells primarily influence their environment through paracrine signaling and can also differentiate into neural lineages, aiding in neuronal repair. Tissue-specific progenitor cells, such as neural stem cells and retinal progenitor cells, offer greater therapeutic precision. This review examines advancements in mesenchymal stem cell-based therapies for neurodegenerative diseases, discusses relevant clinical trials, and highlights the challenges, while proposing that personalized regenerative treatments utilizing lineage-restricted progenitors may improve patient outcomes in these complex disorders.