A team led by Johns Hopkins Children's Center scientists has identified and successfully tamed an overactive protein that plays a key role in cystic fibrosis (CF), a genetic disorder that interferes with the body's ability to transport chloride in and out of cells.
Using a tool called RNA interference on cells in the laboratory, researchers successfully intercepted signals sent out by the rampant protein and prevented cell damage by the protein, effectively restoring the cell to normal.
"The hope is that these findings will be used to design therapies and drugs that go beyond symptom management and actually restore normal cell function to prevent CF," says senior investigator Pamela Zeitlin, M.D., a pulmonologist at the Children's Center, although she warned that they are years from developing or testing such treatments in whole animals or people. A report on the work from scientists at the Children's Center and the University of Maryland appears in the June 23 issue of the Journal of Biological Chemistry.
The overactive protein, called VCP/pr 97 (valosin containing protein), kills a chloride transporter in the cells of the vast majority of CF patients, but quieting the protein restores the cells' ability to transport chloride in and out, researchers found. The inability to transport chloride is the hallmark of CF that causes dangerous buildup of thick, sticky mucous in several organs, including the pancreas and the lungs, leading to malnutrition, chronic lung infections and lung damage.
Cells have a built-in quality-control machinery called ERAD (endoplasmic reticulum-associated degradation), which chemically "marks" defective proteins for destruction and sends them to the cell's waste-disposal complex, called the proteasome. In people with CF, defects in genes for a protein called CFTR (cystic fibrosis transmembrane regulator) interrupt the transport chemistry. Until now, researchers had not identified t
Contact: Katerina Pesheva
Johns Hopkins Medical Institutions