BY AFSHAN NABI (MBG/III)
afshan.nabi@ug.bilkent.edu.tr
“More servants wait on man
Than he’ll take notice of”
-George Herbert
Autophagy literally means “self eating,” and the cells that make up our bodies do it a lot.
Bubbles with double walls (autophagosomes) specifically isolate bits and pieces of the cell. These could be old proteins, mitochondria (energy-producing factories in the cell), lipids, etc. These bubbles are transported along “highways” in the cell to reach other bubbles (lysosomes) that contain tools for digestion. The two different kinds of bubbles fuse together, mixing their respective contents and thus leading to digestion of old, dysfunctional stuff in the cell. The building blocks of these old components obtained after digestion are used for the creation of new things the cell needs.
If the cell is starved of food, this mechanism of autophagy is used to generate energy that helps the cell cling to life in the hope that conditions will get better. But even if the cell has plenty to eat, autophagy does not stop; it helps get rid of damaged material to ensure that the cell remains healthy. Moreover, using the tools of autophagy, the cell can eat up invading bacteria and viruses, again promoting health and survival.
As is common in biology and life, to realize the importance of something, you sometimes need to lose it. With autophagy, the story is the same. Its importance can be realized by studying the cases where it goes wrong. Problems with autophagy create conditions where damage to DNA is more likely to occur, which can lead to cancer. Neurodegenerative diseases (such as Alzheimer’s) are characterized by the accumulation of protein aggregates and dysfunctional mitochondria, which ought to have been cleared away by autophagy. It is also suggested that aging is caused by the “accumulation of unprocessed old material,” and therefore autophagy is believed to constitute an antiaging response. Since autophagy also regenerates amino acids and lipids, it plays a role in metabolic diseases like diabetes. (One of the reasons exercise is healthy is that it promotes autophagy.) Alterations in autophagy also play a role in heart and lung disease.
So, as you can see, autophagy is a big deal. It fights the stresses exterted by different age-deteriorated cellular components. Mostly, it works beautifully, and many have gone through life without being aware of the miracle of autophagy. But when a threshold is crossed, the workload becomes too much. The body cannot eat itself and breaks down, sometimes also leading to a breakdown of the mind.
Nature recycles on both the cellular and a greater scale.
We go through life growing older, grayer and wearier with the years. Then we die and nature claims us. Whether we are buried in the earth, or burnt and our ashes scattered to the winds, we enter the nutrient cycle of nature. The molecules that were us nourish new life, just like amino acids from an autophaged protein are used to create new proteins that will continue to promote life.
Maybe clover and wild grass will grow over our graves; if we are lucky, perhaps poppies and cornflowers, maybe even a wild rose or two. Or a tree whose hidden roots drink from our bones and also from the earth, and which reaches out with its thousand arms to hold the sky.
But in any case, our consciousness will be gone.
How should we live then, while we are conscious?
I feel as if the better part of our world spends a lot of time trying to escape consciousness. The huge cities we have built are crowded, but there is a great emptiness in crowds. Every day, we seek new experiences in the same old ways; our senses are so indulged by stimuli that our minds go deaf, dumb and blind. We become servants to our lowest feelings, and fall into darkness we cannot fight. We should have been free as nature bade us, but we lay down our bodies and forget how to move. We give no thanks for the many gifts we receive, but instead devour them and creep onward to new things. And all of this is made possible by our own choice.
Perhaps we should not shut ourselves off in the glorified holes we call homes and close our minds to our world. Perhaps we should spend our lives studying the world: admiring the trees and grass that grow over unmarked graves all around, the skies, rain and winds that all perpetuate this cycle of life and death. Perhaps we should soak in the warmth of fire, shiver in the cold of water, and run upon the earth with the grace that flying birds embody.
Our bodies are still eating themselves up, carefully keeping us alive. So we can still dream of living well and being free, before nature takes back the molecules it lent us and replaces us with something less conscious.