How to Get Pluripotent Stem Cells
There are 2,604 billionaires in the world…
Yet something like disease, that’s been bothering mankind since the beginning of time, is still something that we can’t get past. We have so many smart and rich people in the world, we still can’t find solutions for what seems to be an everlasting problem.
Something I realized is, we don’t have enough smart + rich people working on problems that actually matter. We don’t have enough people spending time on the world’s biggest problems.
I like to be very intentional with my time, knowing why I’m doing what I’m doing. But I wasn’t always aware of this mindset, I learned to think like this from top philosophers like Naval Ravikant, where he talks about the importance of being intentional about everything that you do. The biggest intention I find behind my research would be my emotional reaction to diseases, it frustrates me looking at victims of diseases, something predetermined, something that they can’t control. That’s the reason behind what I do, but what do I really do?
I’ve been looking at stem cells and their applications in the field of medicine for a few months now, and I’ve been reading + writing articles, attending conferences, meeting with professionals in the field. One of the biggest realizations I’ve had so far (concerning my research) has been realizing that stem cells alone won’t have as near a chance of curing something as combining stem cells with another exponential technology might have. That created a huge twist in how I went about researching, now I don’t read just about stem cells, I read about different combinations of stem cells and other technologies that could provide better and more efficient treatments.
All of this was something I can’t turn my back on, like after having so many conversations with myself I decided that I wasn’t going to wait until university or med school to start working on a problem that affects the world right now. That’s the beginning of my curiosity voyage…
When we think of traditional treatment methods today, we find a lot of barriers in the science itself and that’s what I want to get into.
I’ve mentioned my research in stem cells and I’ve already written a couple of articles on it, in order to talk about some of the concepts that I’m going to go over you need to have a general idea about what stem cells are. If you don’t, nothing to worry about, just read this intro article here :)
When talking about barriers in the core science of stem cells, we find obstacles like disease occurrence in the growth factors used for iPS cells. But there is something that’s even more troubling when we look at growing iPS cells, how we can scale up?
There are always more alternatives to reduce tumor growth in growth genes or other problems the reprogramming process might face, but in the end, it’s about how we can scale up our solution to create cures for diseases.
Let’s look into how we reprogram somatic cells currently:
There are 3 main methods for achieving pluripotent stem cells:
- Somatic Cell Nuclear Transfer (SCNT)
Looking at the diagram above and the name of the process, it seems pretty straightforward to how it works. We start off with two types of cells, an oocyte (from embryos) and a somatic cell (any cell from the body) and exclude the nucleus from the oocyte and isolate the nucleus from the somatic cell. What happens when we do this?
Everything in the oocyte, excluding the nucleus, has the environment for cell growth since its origins are from an embryo and when we transfer the somatic cell nucleus it reprograms the cell to become pluripotent. This process takes a lot of fine details and exact factors to be executed well, like the quality oocyte quality, enucleation, and cell transfer procedures and makes it all the more complicated.
Where we have the most effect in “inducing” pluripotency. In this process, we use four main growth genes(Oct4, Sox2, Klf4, and c-Myc) to reprogram and “trick” the cell into becoming pluripotent. Let’s break down how it works, there are two parts to how this works:
a) Tricking the Cell
No, the cell can’t actually be tricked because it doesn’t have a brain…
What this actually means is that now, the somatic cell’s nucleus is in a position to actually execute based on the gene’s commands. Now the cell “believes” that it can grow, but in reality, without the gene transcription factors it wouldn’t be able to grow.
b) Supplying the Cell
This is the other part of using the transcription factors, not only does it encode this “growth message” inside the nucleus but it also supplies the cell with everything that it needs to become pluripotent.
This process is very promising but still has a lot of problems with using the specific transcription factors: Oct4, Sox2, Klf4, and c-Myc. Two problems that can make or break the treatment are:
- Oncogenic transformation (formation of tumors after using these transcription factors)
- Inefficient (it takes up to 2 months to get the pluripotent stem cells)
Stick with me to the end, to find out about my next steps in solving these problems 👀
3. Cell Fusion
Cell fusion, in terms of PSC, is a process where we have a somatic cell and PSC(like an ES cell) and fuse them to get a hybrid cell that shows pluripotential characteristics but still not identical to the pluripotent cells. Shown above, the nucleus of the hybrid cell that we are left with at the end is half and half, therefore it still has qualities from the somatic cell.
“Cell fusion is the process of combing two uninuclear cells to form a multinuclear cell”
There are several steps when it comes to cell fusion, but to bring it down to three simple steps we have:
This is the beginning of the cell fusion process (that is also the case with stem cell fusion), where both plasma membranes contact each other, bringing the phospholipid layers together at a distance of 0 nm.
Hemifusion is a term that describes the state that the cell is going through in the overall process, and what it means exactly is that the cell is currently half fused. Where both cells are connected, but there is still a phospholipid layer that is in between both the contents of the cells.
There are two variations to this type of process that the cell goes through during fusion:
In a unilateral hemifusion type, there is a simple agreement made between both organisms in the fusion process. This “agreement” in a unilateral fusion process is where only one cell is benefitting off the process, while the other is not harmed. The best example to explain a unilateral fusion process is how a virus and cell interact, where the virus uses the host to create more viruses where the virus is benefitting of the host and the host is not harmed, it’s just overridden.
In a bilateral hemifusion type, there is a mutual understanding between both organisms that they both have something to offer to the other cell, therefore proposing a fusion. At this point in hemifusion, both organisms keep a distance of less than 0 nm, where they start converging and becoming a singular organism.
3.) Pore opening and Expansion
This, in my opinion, is the easiest step to understand and that’s because that’s the end result of the fusion cycle, whether it be unilateral or bilateral. Both the cells, get the energy to overcome the nucleic barrier between them and share all the organelles inside the cell. But it’s what happens after this is where we can find different methods of reprogramming stem cells:
In all of these scenarios, there are different stages that are labeled fusion and reprogramming. We already talked about the basic fusion process, but now the main translation: how does cell fusion help reprogramming somatic cells?
At the end of all these processes, we see the nucleus of the ES cell at the end of the process and that’s because of one main reason, the organelles of the ES cell (not the nucleus) reprogram the nucleus of the somatic cell and become pluripotent. It becomes pluripotent through the programming of the ES organelles, and also has a less chance of being declined by test subjects due to how both the host and the cell have a genetic match (because the somatic cell is from the patient itself).
Now, what do I propose we do about the main barriers that stop us from achieving higher efficiency rates during reprogramming? Interesting you ask because I was just about to tell you.
During the embryonic cell formation, I was reading about the different proteins that come in effect during this transformation, proteins/genes that I could use to enhance the reprogramming process and then I read something about the gene “Mbd3” that actually suppresses the pluripotency effect of embryonic stem cells because they were meant to be differentiated. I was like wait if this a gene that is stopping us from keeping embryonic stem cells into permanent pluripotent stem cells then why don’t we just genetically alter the cell to remove that gene?
I was like “no, it can’t be that simple” until I looked up case studies of researchers that have done this before.
Jacob Hanna and his team have found rates of 90% and higher after using the process of removing this pluripotent hindering gene and introducing two co-activator genes (Oct4, Tet2).
The whole idea of using the transcription factors was that they were trying to revive this pluripotency while them still being suppressed at the same time (the Mbd3 gene) and just created this dissonance inside the cell. Not only does it create this chaos in the cell, but it also creates oncogenic transformation in the cell that used these transcription factors. Overall, this solution kills two birds with one stone, where if we were to implement these in new programming methods not only would we achieve higher success rates but also no disease formation in the stem cell population.
My next steps would be to look more into this technology and find companies that are looking into programming methods and propose a project to look into this process and how it can propel us in our journey in bringing stem cells to the therapeutic market. Keep an eye for a new article breaking down this new way of inducing pluripotent stem cells :)