Winners of the 2019 Nobel Prize in medicine figured out how our cells adapt to oxygen levels

Sketches of the winners.
Sketches of the winners.
Image: Niklas Elmedhed/Nobel Media
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This year’s Nobel Prize in medicine was awarded to three scientists whose work focused on understanding how our cells take in various levels of oxygen.

This fundamental process is key to embryonic development, adapting to high altitude, and exercising. The Nobel Assembly based at the Karolinska Institute in Sweden, which made the announcement early on the morning of Oct. 7, also noted that the process plays a role in developing treatments for anemia, a common blood disorder in which there aren’t enough red blood cells able to carry oxygen to different tissues in the body, along with various type of cancers.

The winners of the prize—William Kaelin Jr., currently at Harvard Medical School and the Howard Hughes Medical Institute in Maryland; Sir Peter Ratcliffe, currently at the University of Oxford and Francis Crick Institute in London; and Gregg Semenza, currently at Johns Hopkins University in Maryland—will split the prize money, worth just over $9 million, equally. Want to understand why their work is important? Take a deep breath, and get ready to dive in.

Physiology at its finest

Every one of your trillions of cells—and really, all animal cells everywhere on the planet—use oxygen from the air to turn food into usable energy.

Oxygen molecules we inhale through the lungs can cross over into tiny blood vessels, where they hitch a ride on the hemoglobin proteins that are present in red blood cells—the body’s life-delivering postal service. Red blood cells ferry oxygen to each tissue, where cells let in just enough to carry out a precise amount of work.

There are two big variables our bodies have to juggle, though: First, depending on where you are, there aren’t always consistent levels of oxygen available. For example, the higher you travel, the less oxygen is available to your body—leading to a condition called hypoxia. Second, your cells need to make more or less energy, and therefore need more or less oxygen, depending on whether you’re being active or sedentary. Healthy individuals can rapidly adjust the amount of oxygen they take in.

This year’s three Nobel prize winners all conducted research that helps explain how cells sense oxygen levels, and how they adapt to higher or lower amounts of the molecule in the atmosphere. When the body detects that less oxygen is present, the kidneys release a hormone called erythropoietin, or EPO, which tells the body to make more red blood cells to carry more oxygen around.

Decades of work from Semenza and Ratcliffe identified how this system works in more detail: They found that a protein called hypoxia-inducible factor, or HIF, rises when there’s less oxygen around. HIF then bonds to sections of DNA near the gene that produces EPO. Extra HIF protein around the EPO gene acts like a turbo charge for the hormone’s production, which is how the body knows to make more red blood cells. When there’s sufficient oxygen available again, HIF levels drop, as do red blood cell counts.

Targets for numerous conditions

Now that researchers understand how the body regulates oxygen uptake, they can try to develop new therapies for individuals for whom that process has gone awry.

Kaelin’s work focuses on how HIF may play a role in diseases. In particular, he focused on the tumor suppressing protein called VHL, Stat reports, which ordinarily causes HIF to break down at a normal rate. Misshapen or insufficient VHL can cause kidney cancers.

Other cancers may be able to develop their own blood vessel system by hijacking the body’s ability to produce new blood cells in oxygen-poor environments, the Guardian reports. And individuals who can’t make enough EPO may suffer from anemia, which results in constant fatigue. The hope is that treatments targeting HIF can be useful in both of these cases—and maybe even for athletes seeking to boost their performance.

This is the second time that this particular line of work has been awarded a major medical prize. In 2016, the trio shared a Lasker award for their work, which is often referred to as the American Nobels.

You can read all of Quartz’s coverage of the 2019 Nobel Prizes here.