Neurodegenerative conditions such as Alzheimer’s disease (AD), Parkinson’s disease (PD), and amyotrophic lateral sclerosis (ALS) occur when neuron populations begin to diminish. There is currently no cure for these types of diseases, though clinical trials to explore various treatment options are ongoing. In particular, regenerative medicine, also known as stem cell therapy, is being heavily researched and has shown remarkable progress in controlling these conditions.
Types of Stem Cells
Stem cells serve as the foundation for every tissue and organ throughout the body. They are unspecialized but have the incredible ability to differentiate into virtually any cell type, as well as the power to self-renew.
Neurodegenerative conditions are characterized by neurons that progressively lose their function and structure, and eventually die off. Because stem cells are able to differentiate into multiple cell types, researchers have begun exploring whether they could replace or repair damaged neurons to control the progression of, or potentially even reverse the damage done by, these illnesses. Existing treatment options are limited, but many researchers are optimistic about stem cells’ potential.
Not all stem cells are the same. Here are the various types, some of which show more efficacy as a treatment for neurodegenerative disease than others:
- Tissue-specific stem cells: These somewhat specialized stem cells can generate multiple organ-specific cells and are typically located in areas of the body that can self-replenish, such as the skin and blood.
- Embryonic stem cells (ESCs): Located in blastocysts, ESCs are especially promising in neurodegenerative applications. Yet, they do pose some risks, including the risk of rejection. Due to their ability to differentiate into neurons, however, they continue to be studied as a potential therapy.
- Induced Pluripotent Stem Cells (iPSCs): iPSCs are artificially derived from adult cells and programmed back to pluripotency, thereby allowing for an unlimited source of any cell type. While they are widely used for developing medications and disease modeling, further research must be done to refine the reprogramming process.
- Mesenchymal Stem Cells (MSCs): MSCs can differentiate into several types of cells. Their self-renewal capabilities are far-reaching, making them an ideal candidate for therapies involving tissue repair. They may also be leveraged for cell transplantation in the treatment of neurodegenerative diseases.
- Neural Stem Cells (NSCs): NSCs are derived from specific areas of the brain and are therefore specialized cells. They, too, are self-renewing and multipotent.
Types of Neurodegenerative Conditions Regenerative Medicine can Help Manage:
While researchers are uncovering new findings on how stem cells can treat neurodegenerative conditions nearly every day, there has already been progress. Here are some of the conditions stem cell therapy has been used to manage:
- Parkinson’s Disease (PD): One hallmark characteristic of PD is the decline of dopamine, caused by the destruction of dopamine-producing brain cells. As dopamine decreases, symptoms such as muscle tremors, challenges with movement, and difficulty thinking arise. Now, researchers have found that stem-cell-derived dopaminergic neurons — in particular, those created through ESCs and iPSCs — could hold success in replacing the destroyed brain cells in individuals with PD.
- Alzheimer’s Disease: Through the use of stem cell therapy, researchers at Columbia University have refined the protocol for a unique process of converting skin cells into brain cells. This option streamlines the process of creating neurons to replace those which have become damaged by Alzheimer’s disease. In their research, the cells were able to receive signals just as normal neurons would.
- ALS: ALS has proven remarkably challenging to study, as there are many potential causes and therapies may therefore only be effective on specific patient populations. Moreover, the motor neurons, which are directly impacted by the condition, couldn’t be acquired in large enough numbers to study. Now, however, Harvard researchers have been able to derive mature cells that can be manipulated back into stem cells from ALS patients, opening up new doors for studying potential therapies to treat the condition.
While there is more ground to cover before stem cell therapy for neurodegenerative conditions can become mainstream, promising research is consistently being published. Moving forward, it’s likely that stem cells will hold the answer to viable management options for these and other challenging conditions.