Autophagy describes the process of degradation and recycling of the cells in the human body. The etymology of the word suggests this itself, as "auto-" means "self" and "-phagein" means "to eat," as the scientific results of Yoshinori Ohsumi discovered in his research.
The concept, based on the larger physical idea of entropy, was first used during the 1960s, when scientists analyzed the process of self-destruction that cells go through. They would close their own content in the membranes, creating some vesicles that would further be transported towards a recycling compartment named lysosome, also responsible for the cellular degradation.
During the early 90s, Ohsumi studied autophagy by analyzing its essential genes using baker's yeast. Once he understood the organic mechanism behind those, he managed to elaborate theories concerning the "similar sophisticated machinery" that is used in our cellular formations. His discoveries contributed to a new understanding of the cellular activity.
The problem with experimenting on yeast and extrapolating conclusions is that however similar the cell structure, yeast cannot be easily observed under the microscope because of their small dimensions. This situation posed serious issues as to whether or not autophagy truly existed in the organisms he analyzed.
The following focus of Ohsumi's work was to determine what the behavior of the yeast cells would be in the case of no vacuolar degradation enzymes in the yeast cells. According to his theory, the autophagy should act as a catalyst in the accumulation of autophagosomes, which would ultimately lead to a visible formation under the microscope.
The cells were genetically modified to lack the vacuolar degradation, after which Ohsumi stimulated the process of autophagy through the starvation of cells. The results changed the scientific approach of cellular behavior! In a matter of hours, the vacuoles' formations were observable under the microscope. They were hosting tiny vesicles that had not yet been degraded.
This led to an entirely new paradigm focused on discovering the crucial significance of autophagy in various physiological processes. From adapting to starvation to the body's reactions to infections, series of organic processes happening in our bodies were found to be related to autophagy. The relevance of these studies comes from understanding its mutations, which can cause several major health conditions, from cancer to neurological diseases.
Discovering that autophagy truly is a consistent process of the cellular mechanisms, Ohsumi created the pillars of cellular characterizations of the process back in 1992. One year later, he had already identified the sine qua non set of genes necessary for autophagy to occur, only to characterize them depending on their functions in later research studies. Thus, he detailed the multitude and complexity of proteins and protein complexes that control autophagy.
"The biological recycling system breaks down old or dangerous proteins and turns them into fresh building blocks for the cell. The same process keeps invading pathogens at bay and prevents the build up of clumps of proteins that can lead to devastating neurodegenerative diseases," explains The Guardian.
Although the existence of this process was known to the scientific world since no less than half a century ago, the paradigm-shifting research of Ohsumi established their paramount importance in treating cells and their degradations, with implications in approaching diseases such as Parkinson's, type 2 diabetes and cancer. His extraordinary contribution in the medical treatment will be awarded a Nobel Prize in Physiology or Medicine.
