Stressful Conditions That Cause Self-Eating: Autophagy within the Cell

This post was authored by Adya Misra, an Associate Editor for PLOS ONE.

Modern life can be stressful and the effects of environmental stressors on the mind have been a topic of interest in recent times. However, how much do we know of how our environmental stress affects our bodies? The research area of autophagy focusses on the mechanisms our cells have evolved to combat stressful conditions: such as lack of nutrition, infection or excess damage caused by daily activities. In this Editor’s Picks, we showcase some of our best papers within the area of autophagy to highlight how the field has grown in the last decade.

Human beings have augmented their waste recycling efforts in the recent decades, however our cells have always had tightly regulated processes that facilitate nutrient recycling and removal of cellular damage in times of stress.

One of these processes, known as “autophagy” was first observed and named by the Belgian scientist Christian de Duve in the 1950s. While studying the effects of insulin on rat liver, de Duve accidentally discovered several processes that are involved in clearing of damage in times of starvation and stress.

Literally translating to “self-eating”, several researchers in the 1970s and 80s began to observe the phenomenon of autophagy under the microscope and discovered various vesicles that were involved in the process of clearing cellular damage. Studying the cell and this process over time, researchers discovered that clearing of damage is facilitated by a structure known as the autophagosome. Although novel and exciting, the research within autophagy was purely observational and no one knew why this process was important for the cell.

Many years later, in 1993, Yoshinori Ohsumi performed some vital experiments using baker’s yeast to discover genes regulating autophagy [1]. He was the first person to clearly demonstrate the effects of the loss of these genes on the physiology of a cell. Yeast lacking genes necessary for autophagy, failed to degrade their damaged proteins in times of stress and could not survive during long periods of nutrient starvation [2]. For his groundbreaking research in autophagy, Yoshinori Ohsumi was awarded the Nobel Prize in 2016 [3].

To celebrate this milestone in Autophagy Research, this Editor’s Picks focusses on the papers published in PLOS ONE that highlight the importance of this research area. In this collection, we have highlighted research from different model systems that has contributed to the field of autophagy. We focus on two consequences of aberrant autophagy: cancer and neurodegenerative disease. Studies in mouse models have shown that the absence of autophagy in certain cell types leads to formation of tumours. Although interestingly, the loss of genes regulating autophagy within the brain causes accumulation of damaged proteins which has been linked to neurodegenerative diseases such as Alzheimer’s and Parkinson’s Disease [4, 5].

We may have known about autophagy since the 1950s, but this area of research remains very active with most of the exciting developments having taken place in the last decade. More work is required to carefully understand how this process is regulated and if we can use this knowledge to develop treatments for cancer patients or indeed patients suffering from debilitating neurodegenerative diseases.

Image Credit: Figure 2 10.1371/journal.pone.0002906