In the news today it was announced that the Japanese scientist Yoshinori Ohsumi won the 2016 Nobel Prize in Physiology or Medicine for his work on the basis of autophagy.
Japanese biologist Yoshinori Ohsumi recognized for work on autophagy.
Molecular biologist Yoshinori Ohsumi has won the 2016 Nobel Prize in Physiology or Medicine for his work in the field of autophagy: the processes by which the cell digests and recycles its own components.
The 71-year-old Ohsumi, who is currently a professor at the Tokyo Institute of Technology in Yokohama, was recognized for his experiments in the 1990s, when he used baker’s yeast (Saccharomyces cerevisiae) to identify genes that control how cells destroy their own contents. The same kinds of mechanism operate in human cells — and are sometimes involved in genetic disease.
“You can answer the most basic and important questions about the nature of life through yeasts.”
“He’s a very humble yeast geneticist who basically transformed the field,” says Sharon Tooze, a cell biologist at the Francis Crick Institute in London. “He was interested in this weird pathway that turns out to be a vitally important pathway in medicine.”
The word ‘autophagy’ — from the Greek for ‘self-eating’ — was coined in 1963 by the Belgian biochemist Christian de Duve, who saw how cells broke down their parts inside a waste-processing sac that he called a lysosome. Biologists now understand that this process is fundamentally important to living cells.
Autophagy is the regulated process in which cells break down their own constituents, such as proteins and organelles like mitochondria, into their more basic parts such as amino acids, and recycle them for later use, either burning them for fuel or using them to make new structures. The cell replaces the old parts that it’s destroyed and replaces them with brand new ones.
In this way, autophagy provides for renewal.
Autophagy is critically important in aging and disease. One of the most characteristic aspects of aging is a decline in the levels of autophagy. Since aging by definition is an increase in the susceptibility to disease, it can be seen how important autophagy is to all diseases.
Autophagy relates to virtually all chronic diseases in one way or another, and even some non-chronic diseases, like infection. It’s important in cancer, cardiovascular disease, and brain disorders such as Alzheimer’s and Parkinson’s.
Autophagy declines in aging. A salient characteristic of youthful organisms is a robust response to stimuli of autophagy, most notably the absence of food, or fasting.
When old, the level of autophagy is only 20% or less in some mammals than that seen in youthful members of the same species. Increasing it to youthful levels is perhaps the most important thing within our control to slow the aging process. (I wrote about this at length in my book, Stop the Clock.)
While fasting and calorie restriction are the best-known ways to increase autophagy, scientists are very interested in developing drugs that will do this as treatment for a number of diseases. This is a hot topic now, with many scientists researching this, and presumably drug companies as well.
To place this Nobel Prize in perspective, it should be noted that Dr. Ohsumi won it for elucidating the molecular mechanisms of autophagy, not for its health implications.
Also worthy of note is that he did his research using the yeast Saccharomyces cerevisiae, the same yeast used in wine, beer, and bread making. This is important because the same mechanisms have been found at work in mammalian cells, showing that the mechanisms have been conserved by evolution, i.e. as single-celled organisms evolved into multicellular organisms, they retained the molecular machinery of autophagy. (An important piece of research on iron and aging also used yeast.)
The Nobel Prize in Medicine went to a worthy recipient, whose research greatly furthered our understanding of the vitally important process of autophagy. Undoubtedly, important discoveries on how it affects health and didsease are yet to come.