Shinya Yamanaka, stem cells, and the Next Generation of Medicine

Japanese researcher Shinya Yamanaka has been a big name in science for years, but now his research has finally been validated by the Nobel committee. He and British researcher John Gurdon and Yamanaka have just been awarded the Nobel prize in medicine “for the discovery that mature cells can be reprogrammed to become pluripotent.” Because of their discoveries, the science of cellular biology has evolved, textbooks have been rewritten, and new fields of study have been invented. After more specific research, doctors will be able to heal things that we never thought could be fixed, and change the way medicine is practiced.

What Are These Cells?

I’m going to attempt to explain iPS cells in a very simplified way. Let’s start with us.

Our bodies are made up of trillions of tiny cells, and everything we do, such as a thought or an action, involves a complex network of messages sent throughout our body. For example, if we step on something sharp, the cells in our feet will send the message (“ahh what the hell!”) to our brain, and we will experience pain. Our brains will then tell us to lift our feet, in an experience we would call a reflex.

But sometimes, cells or the mechanism used to send messages are damaged, or otherwise not functioning properly. This is where stem cells help. Stem cells are like the wild cards of biology – they can turn into any other cell type. For example, if there’s a weak brain cell that’s making it difficult to move, you can take a stem cell, and turn it into a good brain cell that replaces the weak one.

For many years, the way researchers did stem cell research was by using embryos, which is why you may have heard the phrase “embryonic stem cells.” This entails sacrificing an embryo, which raises several problems, such as the ethical concern by most Christians. They don’t like this research because they believe that sacrificing embryos equates to murder, which is why in America, President George Bush put a ban on embryonic stem cell research while he was in office. This was later lifted after President Barack Obama came to power.

This was no longer an issue after Yamanaka worked his magic at Kyoto University. Instead of sacrificing an embryo to change it into a cell of his choosing, he took cells from an already mature host (a mouse was his first subject) and reversed it. It seems like science fiction, but he basically reversed the age of a cell. Let me explain further.

Imagine a baby named Dan. Dan grows up to be a successful lawyer. Then, at age 60, he is dropped into a fountain of youth and reverts back to his baby form. But this time, he doesn’t become a lawyer, he becomes a famous musician. In this example, Dan is a cell, his job is the specific cell function (i.e., as a baby, he’s not mature enough to have a specific function yet), and the fountain of youth is the medical intervention that is used to turn a cell back to its earliest form.

That intervention is what Yamanaka called “Induced Pluripotent Stem Cells” (iPS cells), which bypasses the ethical issue of using embryos, as well as several other practical ones. It uses cells from the host itself, not from a separate embryo; so if you’re operating on someone’s brain, you can take that own person’s brain cell – hell, you could even take a skin cell – and use that, instead using some random embryo and turning that into a brain cell. However, it’s worth mentioning that embryonic stem cells are still the best-understood stem cells, and research on them is still being conducted throughout the world.

What Did The Scientists Specifically Do?

In 1962, John Gurdon (born in 1933) discovered that mature cells – which serve a specific function – can be reversed to its immature form, for which a function has not yet been specified. IBN Live reports:

In a classic experiment, he replaced the immature cell nucleus in an egg cell of a frog with the nucleus from a mature intestinal cell. This modified egg cell developed into a normal tadpole. The DNA of the mature cell still had all the information needed to develop all cells in the frog.

In 2006, Shinya Yamanaka (born in 1962) discovered that mature cells in mice could not only be reversed, but reprogrammed to have a more specific function as a mature cell. The phrase “pluripotent stem cell” means a cell that has the potential to become a multitude of cells, varying from one function to another. In other words, it’s like the baby in my example above – a little cell that could turn into anything.

This video from 2009 explains some of the story behind the iPS cell, showcasing several prominent studies as well as actual footage of stem cell implantation:

What’s the Big Deal?

From the Nobel Prize press release:

These groundbreaking discoveries have completely changed our view of the development and cellular specialisation. We now understand that the mature cell does not have to be confined forever to its specialised state. Textbooks have been rewritten and new research fields have been established. By reprogramming human cells, scientists have created new opportunities to study diseases and develop methods for diagnosis and therapy.

The Asahi Shinbun notes:

Unlike transplants of organs donated from others, the use of iPS cells will not lead to rejections because they can be grown from the patient’s own cells.

Yamanaka’s findings are also expected to help determine the causes of diseases and lead to the development of new medicines.

So if someone with a disease has a damaged cell, it can be taken from a patient, compared to the same cell of a healthy individual, and then reprogrammed to make it all better. Perhaps this is the first step to getting rid of everything from genetically induced hair-loss to childhood blindness.

The Bottom Line

Yamanaka has brought us into a new era of medicine. The future looks bright, and the whole concept of diseases might look totally different in a few decades. What an amazing thought.

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