Nobel Prize for Autophagy Explains Cell Cannibalism

Here's how the body eats itself to stay alive.

A Japanese biologist has been awarded the Nobel Prize in medicine for his research on the body’s self-cannibalistic tendencies. Yoshinori Ohsumi, Ph.D., of Japan’s Tokyo Institute of Technology, has spent the past 30 years studying autophagy (that’s “aw-TUH-fa-gee”), the body’s system for eating up its own cellular trash and reusing the components to rebuild. But if this system breaks down, illnesses like cancer and Alzheimer’s and Parkinson’s diseases result.

The term autophagy — from the Greek auto, which means “self,” and phagein, to eat — was coined in 1963, but its critical importance in the body wasn’t fully understood until Ohsumi’s “brilliant experiments” on yeast in the 1990s, which outlined how it actually works in the body and what happens when it malfunctions. In 1992, he published his seminal paper on the 15 genes that are crucial to the process, which have been the basis for all of the research that’s gone into developing treatments for autophagy gone wrong.

The process is, quite literally, the body’s waste disposal system. Just as in a city, a cell needs to get rid of its trash — broken-down bits of internal structures and waste products — but it recycles waste in an ingenious system. All the crap that’s been rejected from the cell’s institutions floats around the cytoplasm — the cell’s waterway — until it’s looped up by physiological trash bags to form bundles called autophagosomes. These eventually fuse with lysosomes, which are full of garbage-dissolving enzymes that break down and sort the trash into its more useful basic components and release them back into the cell. It’s an incredibly efficient process — when it works.

When it doesn’t, that trash starts to build up, and the cell’s city becomes a hot mess. In Parkinson’s Disease, for example, the accumulation of cellular garbage causes mitochondria to malfunction and proteins and free radicals to aggregate, all of which have been linked to the severe tremors associated with the illness. Alzheimer’s and Huntington’s diseases are the result of similar consequences of autophagy breakdown.

Ramping up waste disposal can also cause huge issues. Cancer cells, dividing rapidly, need all of their internal systems running at full tilt. Turning up autophagy clears out infrastructure-clogging trash and provides the cell with a steady stream of fuel, thereby promoting cancer growth, as a 2015 article in the Journal of Clinical Investigation outlined.

Over the past three decades, researchers have built on the 71-year-old Ohsumi’s pioneering work on autophagy, attempting to figure out why this system sometimes fails (blame bad genes) and how we can design drugs to correct it. It’s very possible that the tireless Ohsumi, who shows no signs of stopping after receiving the 8 million kronor ($930,000) award, will be the one to find out.

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