A Review of Animal Study Evidence for Mesenchymal Stem Cell Therapy to Treat Neurodegeneration
Researchers here assess the present animal study evidence for first generation stem cell therapies to produce benefits in the most common neurodegenerative conditions, and also the consequences of stroke. The results are promising. While these therapies have been fairly widely deployed in patients via medical tourism, that data will never be available for analysis in any useful way. A few formal clinical trials have taken place, with unfortunately mixed results, which suggests that the details of manufacturing process, source of cells, and other logistical factors are important to outcomes. In general, these stem cell therapies appear to reliably modulate chronic inflammation, but all other desired outcomes are quite unreliable where they have been assessed rigorously in human patients. This is one of the reasons why factions within the research community are interested in identifying the most influential signals secreted by transplanted stem cells and using those signal molecules instead of cells as a basis for therapy.
Parkinson's disease (PD) and Alzheimer's disease (AD) are the two most prevalent neurodegenerative disorders. Neurodegenerative diseases are conditions characterized by the progressive dysfunction of nerve cells. This process is primarily associated with cellular aging, which advances with the patient's age. In turn, stroke is caused by vascular factors. Although it is not classified as a neurodegenerative disease, it leads to the degeneration of brain cells. These are severe disorders that frequently impair independent functioning.
As current therapeutic strategies are largely limited to symptomatic management, the identification of disease-modifying treatments remains a major unmet clinical need. Mesenchymal stem cells (MSCs) and MSCs-derived microRNAs (miRNAs) have emerged as promising therapeutic candidates for these conditions. A systematic literature search was conducted. The aim was to synthesize the available evidence regarding the effects of MSCs-derived miRNAs on cellular processes, including apoptosis, proliferation, inflammation, oxidative stress, and motor function in experimental models of PD, AD, and stroke.
A total of 37 preclinical studies were included in the review: 9 focused on PD, 10 on AD, and 18 on stroke. The synthesized evidence indicates that specific MSCs-derived miRNAs, particularly miR-133b, miR-146a, miR-17-92, and miR-223, exert significant neuroprotective effects. These miRNAs actively modulate gene expression, attenuate neuroinflammation and apoptosis, and reduce the accumulation of disease-specific pathological markers, including α-synuclein and amyloid-β (Aβ). Furthermore, targeted delivery of these miRNAs was associated with improved motor and cognitive outcomes across the evaluated animal models.