Neurological diseases represent a group of disorders that affect the central and peripheral nervous system. These pathologies can have a significant impact on the quality of life of patients, as well as their families.
Despite scientific advances, many of these diseases still lack effective treatments. However, research in the field of stem cells has shown great potential in the search for therapeutic solutions.
Stem cells are unspecialized cells that have the ability to differentiate into different types of cells. They can be found in various sources, such as in the developing embryo, in adult tissues, and in umbilical cord blood. Embryonic stem cells and induced pluripotent stem cells (iPSCs) are particularly promising in neurological disease research due to their ability to differentiate into cells of the nervous system.
The use of stem cells in the treatment of neurological diseases is based on the ability of these cells to differentiate into neurons and glial cells. These specialized cells can be used to replace damaged or lost cells in the nervous system, as well as to study the mechanisms underlying these diseases and develop more effective therapies.
The future of stem cell-based therapies for neurological diseases and disorders
Research on stem cells in the field of neurological diseases or disorders, such as autism, spinal cord injury, multiple sclerosis, and stroke, has demonstrated promising results in various studies published in scientific journals. As studies and clinical trials continue, stem cell-based therapies are expected to become an increasingly effective and widely accepted therapeutic option for addressing these debilitating disorders.
Below, I present the most relevant articles and clinical trials that have demonstrated the potential of stem cell-based therapy. I have limited this review to three works in each area, providing a brief summary of the technique and the results in each one.
Stem Cell-Based Therapies in Autism
Autism is a neurodevelopmental disorder characterized by impairments in communication, social interaction, and restricted and repetitive patterns of behavior. In recent years, there has been a growing interest in the use of stem cells for the treatment of autism.
1. Sharma, A., Gokulchandran, N., Sane, H., Nagrajan, A., Paranjape, A., Kulkarni, P., … & Badhe, P. (2017). Autologous bone marrow mononuclear cell therapy for autism: an open-label proof of concept study. Stem Cells International, 2017.
This study provided preliminary evidence of the safety and efficacy of autologous bone marrow mononuclear cell transplantation in children with autism. The results showed significant improvements in behavior, communication, and cognitive skills.
2. Dawson, G., Sun, J. M., Davlantis, K. S., Murias, M., Franz, L., Troy, J., … & Kurtzberg, J. (2017). Autologous cord blood infusions are safe and feasible in young children with autism spectrum disorder: Results of a single-center phase I open-label trial. Stem Cells Translational Medicine, 6(5), 1332-1339.
This phase I clinical trial evaluated the safety and feasibility of using autologous cord blood infusions in young children with autism spectrum disorder. The results indicated that this treatment was safe and feasible, and showed improvements in autism symptoms.
3. Siniscalco, D., Sapone, A., Cirillo, A., Giordano, C., Maione, S., & Antonucci, N. (2012). Autism spectrum disorders: is mesenchymal stem cell personalized therapy the future? Journal of Biomedicine and Biotechnology, 2012.
This review article discussed the potential of personalized therapy with mesenchymal stem cells in the treatment of autism spectrum disorders. The authors suggested that these cells could have beneficial effects on immunological modulation, inflammation, and neuronal function.
Stem Cell-Based Therapies in Spinal Cord Injury
Spinal cord injuries can cause irreparable damage to the spinal cord, resulting in severe motor and sensory disabilities. Studies with stem cells have shown promising results in the repair and regeneration of spinal cord tissues.
1. Vaquero, J., Zurita, M., Rico, M. A., Aguayo, C., Bonilla, C., Marin, E., … & Fernández, C. (2020). Repeated subarachnoid administrations of autologous mesenchymal stromal cells supported in autologous plasma improve quality of life in patients suffering incomplete spinal cord injury. Frontiers in Neurology, 11, 108.
This study evaluated the effect of repeated administration of autologous mesenchymal stem cells in patients with incomplete spinal cord injuries. The results showed improvements in neurological function and quality of life of the patients.
2. Tabakow, P., Jarmundowicz, W., Czapiga, B., Fortuna, W., Miedzybrodzki, R., Czyz, M., … & Raisman, G. (2014). Transplantation of autologous olfactory ensheathing cells in complete human spinal cord injury. Cell Transplantation, 23(12), 1631-1655.
This case study documented the improvement of neurological function and the regeneration of nerve pathways in a patient with complete spinal cord injury after transplantation of autologous olfactory ensheathing cells.
3. Karamouzian, S., Nematollahi-Mahani, S. N., Nakhaee, N., & Eskandary, H. (2012). Clinical safety and primary efficacy of bone marrow mesenchymal cell transplantation in subacute spinal cord injured patients. Clinical Neurology and Neurosurgery, 114(7), 935-939.
This study evaluated the clinical safety and primary efficacy of bone marrow mesenchymal cell transplantation in patients with subacute spinal cord injuries. The results showed that this treatment was safe, and improvements were observed in the motor and sensory function of the patients.
Stem Cell-Based Therapies in Multiple Sclerosis
Multiple sclerosis (MS) is an autoimmune disease that affects the central nervous system, causing damage to the myelin and loss of neurological function. The use of stem cells in the treatment of MS has been the subject of numerous studies.
1. Burt, R. K., Balabanov, R., Burman, J., Sharrack, B., Snowden, J. A., Oliveira, M. C., … & Moraes, D. A. (2018). Effect of nonmyeloablative hematopoietic stem cell transplantation vs continued disease-modifying therapy on disease progression in patients with relapsing-remitting multiple sclerosis: a randomized clinical trial. JAMA, 321(2), 165-174.
This randomized clinical trial compared autologous hematopoietic stem cell transplantation (AHSCT) with disease-modifying therapy in patients with relapsing-remitting multiple sclerosis. The results showed that AHSCT was more effective in preventing disease progression and improving neurological function.
2. Connick, P., Kolappan, M., Crawley, C., Webber, D. J., Patani, R., Michell, A. W., … & Chandran, S. (2012). Autologous mesenchymal stem cells for the treatment of secondary progressive multiple sclerosis: an open-label phase 2a proof-of-concept study. The Lancet Neurology, 11(2), 150-156.
This phase 2 study evaluated the use of autologous mesenchymal stem cells in the treatment of secondary progressive multiple sclerosis. The results showed improvements in neurological function and a reduction in disease progression.
3. Llufriu, S., Sepúlveda, M., Blanco, Y., Marín, P., Moreno, B., Berenguer, J., … & Sáiz, A. (2014). Randomized placebo-controlled phase II trial of autologous mesenchymal stem cells in multiple sclerosis. PloS One, 9(12), e113936.
This phase II randomized placebo-controlled clinical trial evaluated the safety and efficacy of autologous mesenchymal stem cell transplantation in patients with multiple sclerosis. Although no significant differences were observed in accumulated disability, improvements in neurological function and quality of life were reported.
Stem Cell-Based Therapies in Stroke
Stroke is a major cause of disability and death worldwide. Stem cell-based therapies may have the potential to improve neurological recovery after a stroke.
1. Steinberg, G. K., Kondziolka, D., Wechsler, L. R., Lunsford, L. D., Coburn, M. L., Billigen, J. B., … & Marks, M. P. (2016). Clinical outcomes of transplanted modified bone marrow–derived mesenchymal stem cells in stroke: A phase 1/2a study. Stroke, 47(7), 1817-1824.
This phase 1/2a study evaluated the safety and efficacy of transplantation of modified bone marrow-derived mesenchymal stem cells in patients with chronic disabilities caused by ischemic stroke. The results showed significant improvements in neurological function and quality of life in the treated patients.
2. Kalladka, D., Sinden, J., Pollock, K., Haig, C., McLean, J., Smith, W., … & Muir, K. W. (2016). Human neural stem cells in patients with chronic ischaemic stroke (PISCES): a phase 1, first-in-man study. The Lancet, 388(10046), 787-796.
This phase 1 study evaluated the safety and tolerability of transplantation of human neural stem cells in patients with chronic ischemic stroke. Although the study was small-scale, the results suggested that this treatment was safe and showed indications of improvement in neurological function.
3. Bang, O. Y., Lee, J. S., Lee, P. H., & Lee, G. (2005). Autologous mesenchymal stem cell transplantation in stroke patients. Annals of Neurology, 57(6), 874-882.
This study investigated the safety and feasibility of autologous mesenchymal stem cell transplantation in patients with ischemic stroke. The results showed that the transplantation was safe, and improvements were observed in the neurological function and functional capacity of the patients.
Conclusions
Advances in stem cell research have laid the foundation for the development of novel and efficient treatments in the field of neurological diseases. As science advances and more studies and clinical trials are conducted, stem cell-based therapies are likely to become established as an increasingly accepted and effective therapeutic option for addressing these disabling disorders.
The promise of these therapies lies in their ability to address the underlying causes of neurological diseases, rather than merely treating the symptoms. The use of stem cells offers the possibility of replacing or repairing damaged neuronal and glial cells, which would allow a more complete and lasting recovery of brain function in affected patients.
In addition, stem cell-based therapies could offer a more personalized solution tailored to the specific needs of each patient, as stem cells can be genetically modified or programmed to acquire the characteristics necessary to address a particular disease. This could further improve the effectiveness and safety of treatments and reduce adverse side effects.
However, despite these promising advances, there are still challenges that must be addressed before stem cell therapies can be applied in a widespread manner in the clinical setting. These challenges include the need to establish standardized production and quality control protocols, the optimization of cell transplantation techniques, and the assessment of potential risks, such as tumor formation or the appearance of adverse immunological responses.
Ultimately, the consolidation of stem cell-based therapies in the treatment of neurological diseases will depend on collaboration between researchers, physicians, and health authorities, as well as the active participation of patients and society in general. Only in this way can we maximize the therapeutic potential of stem cells and improve the quality of life of those who suffer from these debilitating conditions.
APPENDIX: USE AND TREATMENT OF STEM CELLS IN SPAIN
Legislation in Spain on the use and treatment of stem cells in neurological diseases is regulated by Law 14/2007 on Biomedical Research and specific regulations on stem cells. Below are some key aspects of this legislation:
Embryonic stem cells: Obtaining embryonic stem cells is permitted in Spain, provided that the embryos are surplus from assisted reproduction processes and have informed consent from the donors. The creation of embryos exclusively for research is not allowed.
Adult stem cells: Research and use of adult stem cells, extracted from tissues such as bone marrow or umbilical cord, are permitted in Spain. Obtaining these cells must be done with informed consent and following established ethical protocols.
Cell therapy and regenerative medicine: Cell therapies based on the use of stem cells for the treatment of neurological diseases are permitted in Spain. However, these treatments must be approved and regulated by the Spanish Agency of Medicines and Health Products (AEMPS). Clinical trials and treatments must meet quality, safety, and efficacy requirements.
Ethics committees: Research and use of stem cells in neurological diseases must be evaluated by research ethics committees, which guarantee respect for ethical and legal principles in the development of these therapies.
Informed consent: Both for the donation of stem cells and for their use in research and treatments, it is necessary for patients and donors to give their informed consent, ensuring that they are aware of the risks and benefits associated with the process.
In summary, Spanish legislation allows and regulates the use and treatment of stem cells in neurological diseases, establishing ethical and safety standards to protect patients and donors.
