The news: Three scientists have just been awarded the Nobel Prize in Medicine for figuring out how the cells in our body respond to the levels of oxygen that they receive.
Why do we need oxygen? Our cells use oxygen to convert food into energy.
How does oxygen get into our system? Hemoglobin, on red blood cells, binds to oxygen and carries it around the body.
Our bodies are very clever and figure out how to function during different circumstances. When we exercise for example, our cells need more oxygen, and then when we are done, we don’t need as much. How do our bodies adapt to these situations? There is a protein called EPO that is made in our kidneys. Once this gets out into our blood, it functions to stimulate the production of red blood cells. Therefore, EPO helps to increase the levels of oxygen in our systems.
It was not known how EPO works – what signals the kidney to increase or decrease the amount of EPO in production?
And the Nobel Prize in Medicine goes to….! Three scientists, William G. Kaelin at Harvard Medical School, Peter J. Ratcliffe at Oxford University, and Gregg L. Semenza at Johns Hopkins University were just awarded the Nobel Prize in Medicine for figuring out how this oxygen sensor works.
It was known that there is a protein complex called Hypoxia Inducible Factor (HIF), which binds to EPO when there is less oxygen in the blood, and stimulates it to start working to mediate the oxygen levels in the blood. The mechanism by which HIF is turned on and off though, was not well understood until the three scientists figured it out.
Why is this important? There are human diseases such as cancer, where the cells are rapidly growing and need lots of oxygen. The thought is that if one is able to turn off the oxygen supply to those cells, one could stop their growth. There are other diseases, such as anemia (low levels of oxygen in the blood) and various forms of heart disease that could also potentially be helped by adjusting the levels of oxygen in the blood. Understanding the cellular mechanism by which oxygen levels are sensed and modulated in the blood helps in the design of medicines to treat these conditions.
Written by: Sunaina Murthy