Introduction: Neurodegenerative diseases are caused by the loss of nerve cells. such as Parkinson's disease, Alzheimer's disease, Huntington's disease, Multiple sclerosis (MS) and Amyotrophic lateral sclerosis (ALS). These diseases can be congenital or acquired. Early diagnosis and treatment is the most effective way to treat this disease. Stem cells have been suggested as candidate therapeutic tools for neurodegenerative disorders, given their ability to give rise to the appropriate cell types after grafting in vivo.
Parkinson’s disease (PD) is a very common neurodegenerative disorder that affects more than 2% of the population over 65 years of age. PD is characterized at a pathological level by a progressive degeneration and loss of: (1) nigrostriatal and mesolimbic dopaminergic neurons, leading to tremor, rigidity, and hypokinesia, the classical symptoms of the disease (2) noradrenergic neurons of the locus coeruleus , involved in the progression of the disease, dementia, and depression and (3) serotonergic neurons of the raphe obscurus and medial raphe, also involved in the symptoms of depression, often associated with PD.Several medications can help manage the symptoms of Parkinson's disease. These include levodopa, dopamine agonists, MAO-B inhibitors, and COMT inhibitors.
Amyotrophic lateral sclerosis is a neurodegenerative disorder of upper and lower motor neurons, characterized by progressive muscular atrophy and weakness which culminates in death within 2–5 years. The etiology of neuronal atrophy is unknown, and there is no causal or treatment to slow disease progression.
Two drugs, riluzole and edaravone, reduce the course of the disease. Riluzole reduces glutamate toxicity and increases life expectancy by about three months. The drug edaravone has recently been approved, but no report has been given about its positive effect on the patient's life span.
Methods: PD has long been considered to be one of the most promising target diseases for cell-based therapy. Indeed, numerous clinical and preclinical studies using fetal cell transplantation have provided proof of concept that cell replacement therapy may be a viable therapeutic approach for PD. Clinical studies have shown that transplanted fetal nerve tissue can lead to significant improvements in Parkinson's disease.
recently postulated that stem cell therapy could potentially target several mechanisms responsible for the etiology of ALS and other nervous system disorders, and could be regarded as one of the most promising therapeutic strategies for ALS treatment.There are two basic methods for stem cell transplantation: Systemic and local. One of the known systemic routes is intravenous delivery, which has a less invasive approach, but it is not known whether the injected stem cells can cross the blood-brain barrier or not.
Results: In Parkinson’s disease lthough the source of embryonic tissue for transplantation has its own limitations and ethical issues, human parthenogenesis stem cells are a good alternative for this procedure because they are separated from the unfertilized egg and do not need to destroy the human embryo and can be used to generate an unlimited supply of nerve cells.
In ALS , establishing standardized protocols for cell preparation and transplantation will help generate accurate and reproducible data for future preclinical and clinical studies.
Conclusion: To get an acceptable result and protect the nervous system, it is important to pay attention to several things: 1. Choosing the right cell type 2. Choosing the right cell source 3. Delivery route 4. Avoid suppressing the immune system. It should also be noted that the injected cells do not cause tumor formation in the body.