Mesenchymal Stem Cells and Extracellular Vesicles for Neurodegenerative Diseases: Therapeutic Advances and Challenges

Mesenchymal stem cells (MSCs), as a type of adult stem cells, exhibit robust self-renewal, multi-lineage differentiation, paracrine and immunomodulatory capacities, demonstrating broad application prospects in the treatment of neurodegenerative diseases. This review systematically summarizes the mechanisms of action, therapeutic advances and comparative analyses of various MSCs and their derived extracellular vesicles (EVs) in Alzheimer's disease (AD), Parkinson's disease (PD) and amyotrophic lateral sclerosis (ALS), and discusses the optimization effects of gene modification and pretreatment on therapeutic efficacy. This article not only highlights the advantages of various MSCs and their corresponding EVs, but also provides unique insights into their differentiated therapeutic potential and mechanism of action, which have not been fully elucidated in previous studies. Meanwhile, although current research results are encouraging, this paper also critically points out that existing studies suffer from insufficient elucidation of mechanisms and lack of large-scale clinical trials. Finally, the article prospects future directions of MSC-based therapeutic strategies, including mechanism deepening, treatment optimization and standardization system construction, to promote their translation into clinical application. However, most of the current evidence is still preclinical, and the recognized clinical efficacy in humans is still limited. This is a narrative review. Literature was screened from Web of Science and PubMed by thematic relevance and research quality, without systematic review protocol or meta-analysis.