• Stem Cell-based Treatments for Parkinson's Disease
  • Parmis Zamani,1 Pourya Bakhtiari,2 Yasna Azizpour,3,*
    1. Department of Biology, SR.C., Islamic Azad University, Tehran, Iran.
    2. Department of Biology, SR.C., Islamic Azad University, Tehran, Iran.
    3. Department of Biology, SR.C., Islamic Azad University, Tehran, Iran.


  • Introduction: Parkinson’s disease (PD) ranks as the second most prevalent neurodegenerative disorder, following Alzheimer’s disease. Characteristic pathological signs involve the degeneration of dopaminergic neurons within the substantia nigra and a reduction in dopamine secretion, which results in symptoms like tremors, stiffness in the limbs, facial rigidity, and general body rigidity. However, many non-motor symptoms can precede motor symptoms by several years. Olfactory impairment is a common non-motor symptom in Parkinson’s disease. PD patients exhibit significant dopaminergic neuronal loss and reduced dopamine secretion, so nearly all treatment strategies focus on restoring dopamine levels. Dopamine substitutes or receptor agonists are the most common PD medications; however, they only provide temporary relief of clinical motor symptoms rather than slowing or halting disease progression. Stem cells are unique, undifferentiated cells with the ability to self-renew and differentiate into specialized cell types, making them a key focus in regenerative medicine, particularly for treating degenerative diseases like PD. Stem cell therapy involves transplanting autologous (patient-derived) or allogeneic (donor-derived) stem cells to repair or regenerate damaged tissues. Various stem cell types are being investigated for their potential in treating PD, including embryonic stem cells (ESCs), neural stem cells (NSCs), mesenchymal stem cells (MSCs), induced pluripotent stem cells (iPSCs), and nuclear transfer embryonic stem cells (ntESCs). Recent advancements in stem cell research have shown promise in addressing Parkinson’s disease, with clinical trials ongoing to evaluate their ability to restore motor function, alleviate symptoms, and improve the quality of life for those affected. As research progresses, assessing the safety and efficacy of these therapies remains essential to ensuring their benefits for patients.
  • Methods: The papers included in this article were obtained from the PubMed and Google Scholar databases, using keywords such as Parkinson’s disease, stem-cell human, stem cells, and cell therapy to gather information. Articles that did not align with our purpose were omitted from the study process.
  • Results: Stem cell-based therapies for PD have demonstrated considerable potential, especially through the use of stem cell-derived extracellular vesicles (SC-EVs). These vesicles, which can be modified to improve therapeutic outcomes, present a less invasive and ethically favorable option compared to conventional stem cell treatments. SC-EVs possess the capability to cross the blood-brain barrier, enabling efficient delivery of therapeutic cargo to the brain. In preclinical research, extracellular vesicles derived from mesenchymal stem cells (MSC-EVs) have shown promise in reducing dopaminergic neuron degeneration and enhancing motor performance in PD models. For example, MSC-EVs enriched with certain microRNAs have been effective in lowering oxidative stress and supporting dopamine neuron survival in 6-hydroxydopamine-induced mouse models. Techniques such as preconditioning, drug encapsulation, and surface engineering further enhance the therapeutic potential of SC-EVs by targeting the underlying pathology of PD. Nevertheless, issues like the variability among SC-EVs and the lack of standardized production methods persist. Overcoming these obstacles is essential for progressing SC-EV-based therapies toward practical clinical use, offering renewed prospects for treating Parkinson’s disease.
  • Conclusion: Stem cell-based treatments for Parkinson's disease, particularly using induced pluripotent stem cells (iPSCs), have shown promise in preclinical studies. These cells can differentiate into dopaminergic neurons, which are crucial for addressing the disease's core pathology. Studies in animal models, including non-human primates, have demonstrated improvements in motor function and dopamine restoration. However, challenges such as tumor formation and variable cell survival persist. Ongoing clinical trials, including the FDA-approved ANPD001 trial, are investigating the safety and efficacy of iPSC-based therapies, offering hope for future treatments despite current challenges
  • Keywords: Stem Cell AND Parkinson Disease AND Mesenchymal Stem Cells