Disease of the Day: Cystic Fibrosis

Imagine having a persistent cough that never seems to go away, along with frequent lung infections.  This is something over 70,000 people worldwide live with: cystic fibrosis (CF); an inherited, chronic disease.

I first stumbled upon CF in college and found it to be a fascinating disease since many people suffer from it and there is currently no known cure.  One of my lab rotations in grad school was focused on cystic fibrosis.  For those of you not familiar with CF, it is caused by a mutation in a gene called Cystic Fibrosis Trans-membrane Receptor.  This protein is important in regulating the composition of sweat, digestive fluids, and mucus.  It basically acts as a gate for sodium and chloride on the epithelial membrane.  CFTR is found in the lungs, pancreas, liver, and intestine.  You can imagine then, what might happen when this gene is mutated.  Mucus builds up in the lungs, causing infection and difficulty breathing.

If this disease is caused by one little mutation, why don’t more people have CF?  That’s because the disease is recessive, meaning that both your parents have to have a mutant CFTR in order for you to inherit it.

What exactly is this mutation?  CF can be caused by many mutations, but the most common is called delta F508.  Basically, three nucleotides are deleted in the CFTR gene.  Think of the gene like a tower of legos.  At a certain point, remove three legos in a row.  It may not seem like a big difference, but it’s enough to cause CF.  With this small deletion, the protein can’t fold properly.  When our body makes proteins, it goes through a quality control check to make sure each protein is formed correctly.  If a protein isn’t folded just right, it gets destroyed.  So: deletion leads to misfolding which leads to protein destruction, and mucus buildup.  Isn’t it crazy how something one such a microscopic level can be so crucial?

I find CF to be  fascinating disease.  It’s also an interesting disease to follow in the science world because there is extensive research being done to understand the pathology of CF.  Although people with CF live much longer today than they did 50 years ago, finding a cure for CF is still a desirable goal for many researchers.

Looking through Pub Med today, I found an interesting article that contributes to the known pathology of CF.  It’s called: Phagocytic and signaling innate immune receptors: Are they dysregulated in cystic fibrosis?  This article focuses on the fact that although it is well known that patients with  CF develop lung infection, there isn’t much known about the early stages of these infections developing.  Specifically, they focus on Pseudomonas aeruginosa infection. Pseudomonas aeruginosa is a bacterium that can infect humans.  They found that some of the signaling receptors (things that turn on/turn off cell activity) for Pseudomonas aeruginosa are dysregulated in CF.  In conclusion, CF causes changes in cell activity, allowing for pathogens such as Pseudomonas aeruginosa to infect the body.

It would be interesting to see where they take this study from here.  Maybe targeting these signaling receptors via gene therapy will help alleviate some of the maladies associated with CF.

Although this is an interesting article that aims to understand CF infections, it doesn’t seem to move research forward towards the root of the problem: CF itself and how to prevent the disease from happening in the first place.

A diagram of what CF looks like





One thought on “Disease of the Day: Cystic Fibrosis

  1. Pingback: Disease of the Day: Cystic Fibrosis | The Adventures of an Aspiring World Traveler

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