Protein Lung Diseases

Defective proteins can cause lung disease.

Certain people have a high risk for developing lung disease because of protein abnormalities that make them deficient in lung-protective cell development. According to the National Institutes of Health, defective proteins can cause lung diseases including chronic obstructive pulmonary disease (COPD), cystic fibrosis and lung fibrosis.

AAT Protein

AAT genes can hide until lung dysfuntion persists.

Alpha-1-antitrypsin (AAT) is a protein made in the liver that travels through the bloodstream into the lungs to keep lung tissue healthy. When patients are AAT-deficient, they are likely to acquire COPD in middle age. AAT deficiency occurs when irregularly shaped proteins cannot escape the liver, so the lungs do not receive enough AAT to protect lung tissue. AAT genes are inherited, and many people never realize they have the protein deficiency until the condition causes lung disease.

CFTR Protein

A mucus-producing protein causes cystic fibrosis.

Cystic fibrosis transmembrane regulator (CFTR) is a defective protein found in cells that line passageways in certain organs including the lungs. The inherited cystic fibrosis gene allows cells to make CFTR. The defective protein disrupts the normal levels of salt and water inside the lungs causing thick and dangerous mucus. The mucus causes lung infections by trapping bad germs in the lungs. Cystic fibrosis is a genetic disease than affects children and young adults.

Surfactant Protein C

Defective SFTPC appears to affect the older population.

Surfactant protein C (SFTPC) is thought to play a role in the lung disease, pulmonary fibrosis. When acting normally, this protein keeps lung tissue stable and helps regulate fluid pressure in the lungs. Defective SFTPC is associated with scarring of lung tissue, making breathing difficult and producing a dry cough. Pulmonary fibrosis is a serious disease that is often diagnosed in old age.

Osteopontin Protein

OPN-deficient mice were able to overcome COPD symptoms.

Osteopontin (OPN) is a protein that expresses itself in inflammatory lung conditions and diseases. The protein interacts with many cell-surface receptors including those involved in bone growth, inflammation and wound healing. OPN also has been shown to worsen the effects of autoimmune diseases. Researchers at the University of Texas–Houston Medical School performed a study that showed OPN-deficient mice prone to COPD were able to avoid COPD symptoms after reductions in the protein. The report of the study, published in the FASEB Journal in 2010, also showed elevated levels of OPN among patients with COPD.

Clinical Trials

The American Lung Association reports clinical trials are under way to discover new drug therapies to prevent protein abnormalities that may lead to lung dysfunction and disease. The association also reports that one of the largest web-based clinical trial information organizations helping with this effort is CenterWatch in Boston.

References

• National Heart Lung and Blood Institute: What Is Alpha-1 Antitrypsin Deficiency?
• European Lung Foundation: Alpha-1-Antitrypsin Deficiency
• Baylor College of Medicine: Lung Disease Study Explores Defective Protein Mechanisms
• Medline Plus: Pulmonary Fibrosis
• "FASEB Journal": Adenosine and Osteopontin Contribute to the Development of Chronic Obstructive Pulmonary Disease

Resources

• Medline Plus: Alph-1-Antitrypsin Deficiency
• American Lung Association: In-Depth Resources
• CenterWatch