Stem-Cell Therapy and Its Application in Multiple Sclerosis

Introduction

The function of the nervous system is to establish balance with the outside world through various functions. The nervous system maintains different physiological functions of the body. The central nervous system plays a pivotal role in this process. Diseases like multiple sclerosis are responsible for impairments in nerve functions. As a result, different functions of the body are disrupted. Several treatment modalities are used to treat such conditions. However, new-age treatment options like stem-cell therapy are very effective in curing such disorders.

What Is Multiple Sclerosis?

Multiple sclerosis is an autoimmune inflammatory disease that affects the central nervous system. It is considered the most common chronic inflammatory disease of the central nervous system. The underlying cause of this condition is attributed to the overactivity of cells such as CD4+ T lymphocytes, which are known for their pro-inflammatory properties. As a result, these activated cells inflict damage upon the nerve cells. This damage is characterized by the demyelination of nerve cells, the loss of nerve cells, and the excessive growth of fibrous tissue in nerve cells, such as glial cells. The symptoms associated with multiple sclerosis encompass a range of manifestations, including vision loss, eye-related issues, tremors, sensory loss, and difficulties with mobility.

Pathophysiology:

The activation of the T helper (Th) cells or CD4+ T-cells by the immune pathways is the main causative factor for this process. There are two immune pathways, the adaptive pathway and the innate pathway, that are involved in this process. The interaction between antigen-presenting cells (APCs) and the T-lymphocytes leads to the initiation of the adaptive immune response. The presence of specific antigens in T lymphocytes activates both Th1 and Th17 T-cells. These cells are associated with focal injury to the blood-brain barrier and disrupt its integrity. As a result, inflammatory cells attack the endothelial cells of the central nervous system. Gradually, these cells release several inflammatory mediators that cause further aggregation of B-lymphocytes. B-lymphocyte involvement is mainly seen in multiple sclerosis due to infectious conditions such as the Epstein-Barr virus (EBV). In the innate immune response, microbial products are responsible for the initiation of the immune reaction. The inflammatory cells and inflammatory mediators produced during these processes cause damage to the nerve cells. Demyelination of nerve cells, loss of nerve cells, and fibrous proliferation of glial cells are all related to this type of neural damage. Additionally, conditions like this lead to inflammation in white and gray matter due to immune cell infiltration in specific areas of the brain and spinal cord.

Treatment:

Currently, no treatment option is available for multiple sclerosis. All the treatment options focus on a cure for the immediate complications. Long-term or full recovery is not possible with the current methods of traditional treatment. The current drugs that are available for the treatment of multiple sclerosis are;

• Interferon-Beta: This group of drugs is known to reduce the production of pro-inflammatory mediators like cytokines. Also, they reduce the activity of the suppressor T-cell activity and decrease the disease progression.

• Glatiramer Acetate: This is the mixer of synthetic polypeptides and polymers of amino acids like glutamic acid, lysine, alanine, and tyrosine. These drugs prevent the activation of antigen-specific T-cells. They also have neuroprotective functions and repair activities.

• Monoclonal Antibodies: Several monoclonal antibodies, such as Natalizumab, Alemtuzumab, and Daclizumab, are used for the treatment of multiple sclerosis. These humanized monoclonal antibodies work in various ways, such as blocking the adhesion of lymphocytes to the endothelial cells and inhibiting the migration of the T-lymphocytes.

The drawbacks of the traditional treatment procedure are;

1. The traditional treatment options do not cure the disease. But modify the underlying condition associated with inflammation. This helps to reduce the progression of the disease.

2. Traditional drugs are full of adverse reactions. Monoclonal antibody therapy may cause complications like hypertension, lymphopenia (lack of white blood cells in the blood), thrombocytopenia (a lack of platelets in the blood), and viral infections. Also, they may be responsible for cardiac disorders.

What Is Stem-cell Therapy?

Stem cells are undifferentiated cells which can give rise to other cells. These stem cells can be adult stem cells (ASCs) and embryonic stem cells (ESCs). The adult stem cells can differentiate into a limited number of cells and can only give origin to the specific cells of an organ. These cells are called multipotent cells because of their capacity to produce tissue-specific cells. Depending on their locations, the adult stem cells can be hematopoietic stem cells (HSCs), mesenchymal stem cells (MSCs), and neural stem cells (NSCs). On the other hand, embryonic stem cells may give rise to all cell types and differentiate into tissue types apart from extraembryonic tissues. This feature is known as pluripotency.

What Are the Different Stem-cell Therapy?

There are different types of stem-cell therapy. These therapies are;

1. Hematopoietic Stem Cell Therapy: In this type, the stem cells are derived from bone marrow. These cells have pluripotential and self-renewal properties. These cells may give rise to hematopoietic, and lymphopoietic precursor cells. This type of stem-cell therapy has potency for nerve regeneration and repopulation of the immune system cells.

2. Mesenchymal Stem Cell Therapy: The cells in this therapy are also derived from bone marrow. These cells have the property to differentiate to form osteogenic and adipogenic cells. They even give rise to nerve cells like neurons and glial cells. The regeneration properties of these cells are attributed to anti-inflammatory, low immunogenicity, and multipotency of these cells.

3. Neural Stem Cell Therapy: These stem cells are differentiated into neurons and glial cells. Stem cells derived from this process help in the rejuvenation of nerve cells. The stem cells in this process are derived from bone marrow and may give rise to neuroglial cells and oligodendrocytes.

Conclusion

Stem-cell therapy is a new-age treatment for multiple sclerosis. The goal of the traditional treatment protocols is to limit the inflammation associated with multiple sclerosis. However, stem-cell therapy helps in immune modulation and rejuvenates the damaged nerve cells.