What Are Stem Cells?
Stem Cells: The Basics
When it comes to stem cells, “basic” isn’t exactly the first word that comes to mind. There’s a lot of science, a lot of history, and yes, even a little bit of controversy that can come with stem cells, so it’s tough to know where to start. But stem cells are at the core of who we are — and at the heart of the research we’re doing here at Orig3n — so this is a good first step. In this blog post, you’ll learn what stem cells are, how they work, and why the work we’re doing with them might help you live a healthier life.
What are stem cells?
Stem cells are cells that have the extraordinary ability to differentiate, or transform, into entirely different types of cells — brain cells, heart cells, skin cells, lung cells, and more. We’re made of stem cells — all of our organs and tissues originally grew from clusters of them.
But stem cells also have the potential to repair those same tissues and organs when we’re injured or sick. In many parts of your body, your stem cells already work hard to replenish unhealthy or damaged cells as needed.
Scientists are now researching stem cells because of these remarkable healing capabilities, to see if they can be used in medical and drug development applications.
What makes a stem cell?
Stem cells have three main properties:
- They are unspecialized — meaning they aren’t any one particular type of cell, like a skin cell or a heart cell.
- But they can differentiate into more specialized cells, like liver cells, heart cells, and brain cells.
- They also have a limitless self-renewal process — that is, they have the ability to divide themselves into other stem cells over and over again, without differentiating.
How are stem cells classified?
Although, by definition, every stem cell has the ability to differentiate into different types of cells, some stem cells can transform into more types than others. Stem cells are therefore classified by their potency — that is, how much potential they have to differentiate. There are 5 levels of potency, listed here from highest to lowest:
- Totipotent — can differentiate into all possible cell types.
- Pluripotent — can differentiate into almost every cell type.
- Multipotent — can differentiate into a related family of cells (e.g., different blood cells)
- Oligopotent — can differentiate into just a few types of cells.
- Unipotent — can split into only one cell type.
What are the 2 main types of stem cells?
1. Embryonic Stem Cells — Formed in embryos during the blastocyst phase of biological development, these stem cells have the ability to become any other cell type in the body. Most embryonic stem cells are derived from eggs that have been fertilized in vitro and then donated for research with donor consent.
2. Adult Stem Cells — Every person has millions of adult stem cells in their body, found in the brain, blood, skin, liver, and many other parts of the body. These cells work to heal us, and can be derived directly from an individual’s blood, organs, or tissues.
Although embryonic stem cells are more potent than adult stem cells — meaning they can do more and potentially be more helpful in scientific research — because they come from embryos, there is sometimes controversy surrounding their use. This led scientists to look for other sources of stem cells.
What are iPS cells?
In 2006, Kyoto University researchers Shinya Yamanaka and Kazutoshi Takahashi discovered conditions that allow skin or blood cells to be genetically reprogrammed, or de-differentiated, back to an embryonic stem cell state. These induced pluripotent stem cells (often called iPSCs, or iPS cells) can become almost any other type of cell, differentiating into liver cells, heart cells, brain cells, and more. In 2012, Yamanaka won a Nobel Prize for his work on this incredible discovery.
How do iPS cells fit into stem cell research today?
After the Yamanaka and Takahashi discovery, scientists around the world began studying iPS cells. Today, although still relatively new, iPSC technology is quickly becoming the foundation of regenerative medicine research — with the idea that iPS cells could be used to regrow and repair tissue and organs. Scientists are also excited by the prospect of using iPS cells for a more personalized approach to treatment, as each individual could potentially have a matched supply of stem cells in his or her tissues.
One particular benefit of iPS cells is that they inherently eliminate some of the ethical problems that come with embryonic stem cells, as induced pluripotent stem cells are adult cells that can be derived directly from blood.
What’s next for stem cell research?
Here at Orig3n, we’ve made it our mission to harness the power of iPS cells. We’ve created the world’s largest human cell bank, crowdsourced from donors around the world to help drive our iPSC research. Our ultimate goal is advance regenerative medicine, developing treatments and therapies that will help people everywhere.
Stem cells by their very nature are all about potential — in them, we see dozens of possible applications in modern medicine. From drug testing to modeling disease systems to regenerative medicine treatments, we’re proud to be the ones tapping into that potential.
References:
https://stemcells.nih.gov/info/basics/1.htm
https://medlineplus.gov/stemcells.html
https://stemcell.ucla.edu/induced-pluripotent-stem-cells
https://stemcells.nih.gov/info/Regenerative_Medicine/2006Chapter10.htm
http://www.nature.com/news/how-ips-cells-changed-the-world-1.20079