Announcement of the 2016 Nobel Prize in Medicine or Physiology

Transcript

good morning to Nobel forum and the press conference uh for the announcement of this year's Nobel Prize in physiology or medicine so what I will do is to first read the announcement in Swedish uh and then in English and then we will proceed to some scientific background information uh and then we will open up for questions Noel shaming Carolin inst... Read More

Summary

This video is a press conference for the announcement of the Nobel Prize in Physiology or Medicine. Yoshinori Ohsumi is awarded the prize for his discoveries on the mechanism of autophagy, the process by which cells reduce their own components to release energy and build new functional parts. Autophagy is now known to regulate important physiological functions and is associated with many human diseases.

Questions & Answers

Q: Can you provide some scientific background information on autophagy?

Autophagy, derived from the Greek word meaning "self-eating," is a process observed in cells where they reduce their own components to release energy and build new functional parts. It was first observed in the 1960s, soon after the discovery of lysosomes, which contain enzymes that disassemble proteins, sugars, and lipids. Another organelle composed of a double membrane, called an autophagosome, was also observed. Autophagy was associated with cells under stress, such as during starvation.

Q: How did Yoshinori Ohsumi study autophagy in yeast cells?

Ohsumi used baker's yeast cells, which contain a single large lysosome known as the vacuole, to study autophagy. He devised a method to visualize the accumulation of autophagosomes in the vacuole by making star cells unable to degrade the content of the vacuole. Using this method, he searched for mutants that had lost the capacity to activate autophagy. He identified as many as 15 essential autophagy genes in yeast cells.

Q: What did Yoshinori Ohsumi discover about the molecular mechanism of autophagy?

Ohsumi discovered that stress signals initiate a cascade of events that control each step in the formation of the autophagosome. This includes the fusion of vesicles, extension and bending of membranes to sequester cargo, and finally, fusion with a lysosome where the content is broken down by lysosomal enzymes. He also identified genes that control autophagy in mammalian cells.

Q: How does autophagy regulate physiological functions and human diseases?

Autophagy is involved in important physiological functions such as cell differentiation. It allows the body to cope with starvation and stress by recycling part of the cellular content and capturing invading viruses and bacteria. Autophagy is also responsible for removing damaged proteins and organelles, promoting cell renewal. Failure of autophagy is associated with cell aging and diseases like Alzheimer's disease and type 2 diabetes. However, autophagy can also promote the growth of tumor cells and resistance to cancer drugs.

Q: Are there any concrete trials with drugs that interfere with autophagy?

There are currently many clinical trials ongoing to develop drugs that either stimulate or counteract autophagy. While there are no drugs on the market yet, there are many activities and attempts to find ways to tailor treatments. The specific mechanisms of how these drugs affect autophagy are still being studied.

Takeaways

Yoshinori Ohsumi's discoveries on the mechanism and significance of autophagy have been instrumental in revealing the fundamental physiological process. Autophagy regulates important functions of cells and is associated with many human diseases. The knowledge gained from this research is expected to lead to the development of new strategies for the treatment of various diseases.