Our Cells are always talking to each other. But can we hear what they are saying?
Every day, mail services like USPS process and deliver hundreds of letters. Occasionally, letters get sorted incorrectly and a letter addressed for someone else arrives at your door. Just like we write and send letters to communicate with others, cells write and send letters through an internal mail service to communicate with one another.
The cells that make up our bodies are in constant communication with each other to ensure that our bodies keep functioning correctly. They do this using chemical signals – molecules created by a cell that are later released into their surrounding environment, like blood or muscle tissue. Once the chemical signal is released from a cell, it can be delivered to a neighbor cell that takes that chemical signal and reads it. The neighbor cell then replies to the message with a new chemical signal and sends it off to the next neighbor. Like a giant game of passing notes in class with thousands of cells, chemical signals keep getting exchanged.
One of our body’s most important defenses against foreign invaders – like the flu virus – is inflammation. It is one part of a large network of biological processes known as the immune system. Inflammation is the reason you feel pain, warmth, redness, and swelling at the site of injury when you get a flu shot. That’s because the injured skin cells use chemical signals to alert blood-circulating immune cells that they need help!
When cell communication is working well, chemical signals sent by injured cells arrive at the doorstep of immune cells who spring into action. Once immune cells arrive at the injured site, the injured cells stop sending their ‘help’ signals and immune cells start sending their ‘repair’ signals. Eventually, our body heals, and the inflammatory response stops. But when damaged cells and immune cells never stop sending their ‘help’ and ‘repair’ signals things get out of control. Your body takes longer to turn off the inflammatory response leading to chronic inflammation. Just like a postal worker doesn’t process one letter a day, a cell doesn’t process one signal at a time. They’re processing hundreds of signals every minute so mistakes are bound to happen, and chemical signals will get sent incorrectly.
However, what if there were some signals slipping through the cracks that no one ever knew were there?
Inflammation is a large biological process that is a bookmark for almost every illness, disease, or trauma our bodies might encounter. When signaling goes haywire and inflammation persists, it can be hard to determine what chemical signals are related to disease progression against the hundreds of other signals our cells are processing. Almost like if you tried to pull out a letter addressed to you in a massive pile of letters that all look the same, it would basically be impossible. Some chemical signals that are allowing disease to progress fall through the cracks or blend into the background environment because they are disappearing before analysis methods can detect their presence.
Scientists, like myself, want to advance our understanding of disease progression by studying the chemical signals cells use to communicate, so, we need to improve analysis methods. The hope is that by capturing and identifying signals that are disappearing quickly, we can develop new therapeutic treatments to stop disease progression at an earlier stage.
Tammi van Neel is a Ph.D. candidate in the Chemistry department at the University of Washington. She develops analytical tools and methods to study how cells communicate with each other using beads that capture small, short-lived signaling molecules.