In the future, it is likely that analysis of an individual’s glycans will be used to predict our risk for developing diseases like rheumatoid arthritis, cancer or even food allergies. This is because glycome alterations can be specifically tied to particular disease states. Also, biological processes like aging are linked to inflammation in our glycome. It remains to be tested if reversing these changes can help prevent disease, or even slow aging – an intriguing possibility.
Along with DNA, proteins, and fats, glycans are one of the four major macromolecules essential for life. Of these four, glycans are the final arbiters of how our cells behave.
DNA orchestrates what we look like, our capacity to think and behave, and even determines the diseases to which we are most susceptible. Within our DNA are short segments, genes, which often contain instructions for how to synthesize proteins. Proteins in turn are the “workhorses” of the cell, carrying out many of the functions necessary for life.
However, how a protein behaves often depends on what glycans are attached to it. In other words, these sugar molecules can greatly influence how our proteins do their work, and even how our cells will respond to stimuli. For example, if you change a few glycans on the outside of a cell, it might trigger that cell to migrate to a different location in our body.
The main job of glycans is to modify the proteins and fats that sit on the surface of our cells. Together, they create a thick sugar coat around the cell. If we consider the surface of the cell to be soil, then glycans would be the wonderfully diverse plant-life and foliage that sprout up and bring color and identity to the cell. In fact, if you were able to see a cell with your naked eye, it would look very fuzzy. Picture a peach with 10 times more fuzz.
Every single cell in the human body is covered with a collection of glycans which are assembled using various simple sugars like glucose, mannose, galactose, sialic acid, glucosamine and frucose as building blocks. By sensing the type of sugar coat present, our immune cells can identify other cells as friend or foe. This is because bacteria have sugars on their surfaces that are never seen on human cells – the pathogen’s sugars are sensed by the immune system and that identifies the bacteria as ‘foreign.’ Emanual Maverakis, CC BY-SA