Stem cells are a very unique type of cell. Unlike every other cell, they are unspecialised. Meaning they have the potential to become any type of cell they want.
Its for this reason that so much research has gone into learning how stem cells work, and how to create them. If we could create a neuron, we could treat Parkinson's disease and spinal cord injuries.
If we could create insulin secreting cell we could cure diabetes.
If we could create Skin cells, we could aid burn victims.
If we could create retina cells, we could cure some kinds of blindness.
The thing is, as our cells specialise, certain genes are turned off, and others are left on. This means, some genes are read while others aren’t.
Reading a specific genetic sequence leads to the production of specific proteins.
Meaning the cell eventually looks a certain way to perform its function.
The only problem with stem cells is finding them. We all start with stem cells in the womb. Then they begin to specialise, turning into a muscle cell, neuron, skin cell, skeletal cell etc.
However ones we are adults, our ability to create stem cells is all but gone.
There are a few ways we can get stem cells, but each way at the moment has its problems.
As we said before, when we are first conceived we are all stem cells. The first 200 cells produced have the ability to become anything (undifferentiated), but we can’t simply take these cells and put them into someone else.
Doing this causes an immunological response, meaning your body would start attacking these foreign cells.
What we can do however is called Therapeutic cloning.
We take the zygote (cell after the sperm and egg combine) and replace the nucleus with the patient’s nucleus.
They use a combination of caffeine and electric shocks to bind the new nucleus to the cell and jump start the dividing process.
Once inside the embryo, the nucleus is re-programmed, meaning all the genes are switched back on. This process is still not 100% understood.
In our bodies, right now, we have adult stem cells.
The main difference between adult and embryonic stem cells, is the amount they can differentiate.
Unlike embryonic stem cells, adult stem cells are limited in what they can become, and thus aren't as useful as embryonic, however they are less controversial.
We have already talked about briefly about the process of cloning and stem cell development. Lets take a look at how we hope to use stem cells in the world.
To the right is a video showing how stem cells are used in treating mice who are paralysed from the waist down.
You’ll see only 2 weeks after the surgery, the mice regain some control. 10 weeks after, and they are almost at 100% recovery.
Treatment using stem cells
At this stage we can differentiate between therapeutic cloning and somatic cellular Cloning.
If we keep the zygote outside a womb and allow it to multiple it will only create more stem cells (therapeutic)
However, if we place it into a womb, then it will begin to develop into a full organism.
You may have heard of dolly the sheep. This sheep was a clone, create through somatic cellular cloning.
However the process isn’t that simple, a lot of the time the nucleus doesn't take to the egg. In fact dolly the sheep was created on the 277th try, meaning there were 267 failures before that.
Cloning and stem cell treatment has come under a lot of scrutiny. There are both ethical and biological issues which surround these topics. Its important to educate your self on the topic before jumping to conclusions.
