Restoring Function to the Central Nervous System Using Stem Cells
Conventional medicine can do many amazing things when it comes to your body: it can help you shrug off diseases that used to kill thousands, regain partial hearing, and even keep you alive if you’re born too early, but what it can’t do is regrow your nerves. If you get in an accident, damage your central nervous system(CNS), and come out alive, in 9.8 out of 10 cases you’ll be stuck in a wheelchair for the rest of your life. And even if you retain some limited range of motion, your muscles will start to atrophy and you’ll lose muscle mass.
Does that scare you? It should.
60% of people with spinal cord injury(SCI) are left quadriplegic while most of the remaining 40% percent are paraplegic. Normal medicine can’t do much — or, more accurately, — can’t do ANYTHING for people with SCIs.
This is where induced pluripotent stem cells come in.
A stem cell is any cell that has the capacity to grow into another kind of cell. But, most stem cells that adults have can only turn into related cells. For example, a muscle stem cell will only ever turn into a muscle cell. However, induced pluripotent stem cells(IPSCs) can turn into ANY kind of cell. This means that they can be used to treat virtually ANY sort of injury.
Regenerating the CNS
The most basic parts of your nervous system are neurons. Even larger parts of it are essentially just really long neurons. Your spinal cord, for example, is just a bunch of extremely long axions(sometimes up to a meter in length!) that are surrounded by a tube of tissue. Damage to this tube or the neurons inside will paralyze you below the point of injury.
The conventional treatment of SCIs is to put the injured person in a wheelchair and hope that the nervous system will heal. Sometimes this works and a very limited range of motion is restored. Obviously, hoping for the best is not a very effective medical practice, but introducing cells whose whole purpose is to heal damaged parts of the body is considerably more effective.
The first step in healing the nervous system with stem cells is actually creating usable stem cells.
Inducing pluripotency in cells
Creating IPSCs is a relatively simple process that has some unpredictable outcomes. First, adult cells are collected from the patient’s body, usually from the skin. Next, CRISPR is used on the genes Klf4, Sox2, Myc, and Oct4 to change how they express themselves. This undoes the programming on the cell which reverts it to a pluripotent stage. Pluripotency means that a stem cell can differentiate into almost any other kind of cell.
IPSCs are often regarded as one of the biggest medical breakthroughs of the last century — and with good reason. They have amazing potential in a lot of medical fields, but especially when regarding the nervous system. As I mentioned before, the nervous system is very slow to heal and is impossible to transplant due to its complexity. But with IPSCs you can use a person’s own cells to heal them.
Differentiating IPSCs into Neural Progenitors and NSCs
Neural progenitors are a special group of cells that are created from IPSCs. They can, in turn, grow into neural stem cells(NSCs). NSCs are cells that actually create new neurons in your body
By exposing IPSCs to cytokines and growth factors while culturing them in Petri dishes with stromal feeder cells, they are “reprogrammed” or differentiated into neural progenitors. These progenitors undergo a similar process which further differentiates them into NSCs.
The NSCs are then implanted into the site of the injury where they’ll soon start creating new neurons to heal the nervous system.
The Process
Above was a brief description of the scientific methodology behind it, but here’s an explanation of the process of doing all this.
- The patient comes into a clinic and cells are taken either from their skin or fat tissue in a minimally invasive procedure.
- The cells are then converted into IPSCs in a procedure that can last several days. Note: This step is where the largest number of problems occur. Sometimes the IPSCs mutate in unpredictable ways because of the time they are isolated from the body
- The cells are then implanted into the spine for the first time and will have to be injected many more times over a period of multiple weeks before you start to see considerable results.
Results will take time to become clear, but overall, this is a relatively simple process that yields massive results.
This sounds big. Who’s working on this currently?
Some of the companies in the United States working on using stem cells in the nervous system are Neuralstem Inc. and the US Stem Cell Clinic.
- Neuralstem Inc. is working with a lineage of NSCs called NSI-566 in order to create a localized cell therapy that aims to protect and/or regenerate stem cells in the spine. If successful, this could mean the end of dozens of degenerative diseases.
- The US Stem Cell Clinic ran treatment on a young man who had been wheelchair-bound after being paralyzed. In a similar procedure as what I described above, US Stem Cell Clinic treated him 8 times before he regained some limited use of his lower body. Learn more about them in this talk by their CSO Kristin Comella 👇.
Closing Thoughts
- Stem cells have the potential to be one of the biggest breakthroughs in medicine.
- Adult cells →IPSCs →Neural Progenitors →NSCs →Various types of neurons → → →potentially miracle cures!
- You’ll need multiple treatments to restore your nervous system but this is a good thing because it lets you be treated multiple times
- Can be applied to injuries caused by almost any type of accident
Seeing that there is no way to transplant or manually heal the nervous system, stem cell therapies are absolutely our best chance at treating injuries to the central nervous system. Soon, people with crippling injuries might be healed almost completely.
Wait! Don’t go yet…
I hope you enjoyed reading this article! I’m a 15-year-old innovator at The Knowledge Society committed to changing the world using new technologies like AI, Gene Editing, and BCIs. If you want to learn more or are interested in talking, email me at veda.bhattaram@gmail.com
