For years, scientists have been studying cystic fibrosis, one of the most common and deadly genetic diseases, using gene-altered mice. But there had always been a catch: Cystic fibrosis, which is incurable, attacks mainly the lungs and digestive system, and lung failure is the leading cause of death. However, despite their high level of homology with humans, mice don't develop lung disease like people with cystic fibrosis do.
Now, researchers have taken the first step towards developing a cystic fibrosis model that more accurately mirrors the disease in humans. And guess what they're using?
"Compared to mice, pigs may be a good model for human genetic diseases because their anatomy, biochemistry, physiology, size and genetics are more similar to those of humans," said study author Randy Prather, distinguished professor of reproductive biotechnology at the University of Missouri's College of Agriculture, Food and Natural Resources. "We believe that this discovery could lead to additional uses of the pig when studying other diseases. The pig is very much like humans in many respects and may be a key to finding cures, treatments and therapies for many diseases that affect the world."
Prather and his partner on the project, Michael Welsh from the Howard Hughes Medical Institute at the University of Iowa, created the genetic defect in pigs, but the animals carry only one copy of the mutated gene, and therefore do not yet display signs of cystic fibrosis. But the researchers, whose study will appear in the upcoming edition of the Journal of Clinical Investigation, are hoping that this spring, naturally bred pigs with both copies of the affected gene will show symptoms like those associated with cystic fibrosis in humans. At least 11 mice models have been developed to study cystic fibrosis, but none of them spawned the spontaneous lung disease that researchers need to investigate.
"Although scientists and physicians have learned much from studying cystic fibrosis in mice, to make progress and improve treatments, we need an animal that at least partially mimics the lung disease of humans," Welsh said. "We also are working with other University of Iowa researchers who are doing similar work with ferrets."
But science marches on, and if a more porcine approach is what's necessary to combat this horrific disease, we're all for it. As Welsh put it: "We hope that these first steps will ultimately provide scientists with the means to better probe cystic fibrosis and aid those who suffer its ravages. We have our fingers crossed that these animal models will help."