Arif Hoque-
Let us consider that your country is going through a tough economic condition. And you are struggling to cope with your financial stress due to a burgeoning price hike. What will you do in this situation?
You may either look out for an alternative income source or search for leftover or unused materials from your household that may be recycled or have a useful application. In this way, you can cut down your expenses and at the same time, tidy up your house through waste material recycling.
Now, what if I say something similar also happens in our bodies? Would you believe that?
Dear reader, it is absolutely true!
Japanese cell biologist Yoshinori Ohsumi won The Nobel Prize in Medicine in 2016 for discovering the mechanisms of a similar phenomenon happening in our body known as “autophagy”. Meaning “self-eating” in Greek, it is the body’s process of breaking down and recycling unnecessary or less efficient cellular components. Removing damaged proteins from our cells, this process creates a way for growing stronger and most efficient proteins.
Our cell’s powerhouse mitochondria sometimes may get damaged and need repair or replacement. Autophagy serves this purpose by recycling the cells. It is not only just a waste-removal process but also a natural way of utilizing the waste or damaged cells without any side effects.
Autophagy is a fundamental process that enables cells to recycle and renew their internal components, giving them the energy and nutrients, they require to perform their jobs. It is essential for the maintenance of cellular homeostasis, as it helps to remove damaged organelles, misfolded proteins, and other unwanted cellular components.
The immune system, cell differentiation, and embryonic development are all significantly influenced by autophagy. Many disorders, such as cancer, diabetes, and Huntington’s disease, can develop as a result of a breakdown in autophagy. A strong autophagy system is associated with long life, and a weak one can hasten the onset of aging signs.
Yoshinori Ohsumi, a professor at the Tokyo Institute of Technology, began his work on autophagy in the 1990s when very little was known about the process. He studied how cells recycle their own components using yeast cells as a model system. He discovered that when yeast cells were deficient in nutrients, they started destroying their own organelles and proteins to produce energy. Ohsumi uncovered the genes responsible for this process and demonstrated that humans are among the many animals in which they have been conserved. Ohsumi published the findings of this significant discovery in 1992.
Our understanding of autophagy, particularly the molecular mechanisms underlying this process, has considerably benefited from Ohsumi’s work. His studies have demonstrated that the process of autophagy, which involves many different genes and proteins, including those associated with autophagy (ATG), is tightly controlled. Ohsumi identified and characterized these genes and their functions in autophagy using yeast as a model organism. He found the first ATG gene and then numerous others, exposing the intricate web of interactions that go into autophagy.
Ohsumi’s study has also demonstrated how different signaling pathways, such as the TOR (target of rapamycin) pathway, which is essential for cell development and metabolism, control autophagy. Ohsumi revealed a brand-new regulatory mechanism for autophagy by demonstrating how the TOR system controls autophagy by suppressing the expression of ATG genes.
One method to trigger autophagy is intermittent fasting. When the body is deprived of regular or usual nutrients, the body shifts from an anabolic state (which builds up cellular components) to a catabolic state (breaking down cellular components). This catabolic state triggers the initiation of autophagy, allowing the body to break down damaged organelles and proteins and recycle their components to maintain cellular homeostasis.
Significant autophagy in humans may require two to four days of fasting, depending on the person’s metabolism. When blood levels of insulin and glucose fall significantly, autophagy is thought to start. Some studies have detected autophagy in human cultured neutrophils (the most abundant type of immune cell in the blood) after 24 hours. Yet, there is no definitive human research that points to the ideal fasting duration for achieving autophagy.
Although autophagy has been understood for more than 50 years, Yoshinori Ohsumi’s paradigm-altering study allowed for the recognition of its basic significance in physiology and medicine. For instance, his research has clarified the role of autophagy in the emergence of cancer. Though it has been found successful in preventing cancer or tumor growth in the initial development stage, some cancer cells at an advanced stage use autophagy as a survival mechanism, allowing them to withstand the stresses of chemotherapy and radiation therapy. By targeting the autophagy pathway, it may be possible to enhance the effectiveness of these treatments and improve patient outcomes.
Ohsumi’s work also has ramifications for neurological diseases like Parkinson’s and Alzheimer’s. The accumulation of harmful proteins in the brain is a hallmark of both of these disorders, and autophagy is assumed to be involved in their elimination. Researchers may be able to create new treatments that encourage the removal of these harmful proteins and halt the course of these diseases by better understanding how autophagy functions.
Ohsumi’s research has also provided insight into how autophagy plays a part in viral diseases. In order to survive inside host cells, many pathogens, including bacteria and viruses, can hijack the autophagy process. Researchers may be able to create new treatments for these diseases by preventing their capacity to influence the autophagic process by better understanding the processes of autophagy.
In addition to its implications for disease, Ohsumi’s work also sheds light on fundamental cellular functions. Studying the intricate process of autophagy, which requires the coordinated action of numerous distinct genes and proteins, has helped researchers better understand how cells work. Beyond medicine, this research-based knowledge might be used in the creation of novel technologies. It has also served as a reminder of the importance of basic research in advancing our understanding of complex biological systems.
Arif Hoque is an education activist and science writer. He is the President of Bangladesh Biggan Porishod, Head of the Chemistry Department at Shikho Technologies, and Director of Monon Academy
