Related Experiment Videos
Future pharmacological treatment of cystic fibrosis
1Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA. pzeitli@jhmi.edu
Abstract:
Cystic fibrosis (CF) is an autosomal recessive disorder that is caused by over 850 different mutations in the CF gene. It is useful to group these mutations according to the defect that results in the CFTR mRNA or protein. New pharmacological treatments targeted towards specific mutations that are relatively common are being developed. Class I mutations do not produce CFTR protein because of a premature stop signal in the CFTR DNA. These null mutations can be corrected by certain aminoglycosides which cause the aberrant stop signal to be skipped. Mutations leading to a CFTR protein that attains an unstable structure shortly after translation in the endoplasmic reticulum form class II. Class II mutations can be restored to the protein trafficking pathway by manipulation of chaperone protein/CFTR interactions with chemical chaperones or drugs that affect gene regulation such as the butyrates. Production of a CFTR with reduced Cl(-) transport on the basis of abnormal regulation of the chloride channel is the basis of class III. Genistein can overcome this block in regulation. Mutations that partially reduce chloride conductance through CFTR (class IV) can be stimulated with milrinone, which is a phosphodiesterase inhibitor. Finally, mutations that lead to a severe reduction in normal CFTR protein form class V. Increased levels of CFTR could be generated with the butyrates or supplemented with gene therapy. Although most of the reported mutations in CFTR are rare and unclassified, it may be possible to use genotype-phenotype correlations to determine the best approach.
Insights
Cystic fibrosis (CF) treatments are advancing with targeted therapies for specific CFTR gene mutations. Different mutation classes can be addressed by drugs that correct stop signals, improve protein folding, or enhance chloride transport.
Area of Science:
- Genetics
- Pharmacology
- Molecular Biology
Background:
- Cystic fibrosis (CF) is an autosomal recessive genetic disorder caused by over 850 mutations in the CFTR gene.
- Current research focuses on developing targeted pharmacological treatments for common CFTR mutations.
- Classifying CFTR mutations based on their molecular defects is crucial for personalized medicine.
Purpose of the Study:
- To categorize CFTR mutations based on their impact on CFTR protein function.
- To review existing and emerging pharmacological strategies for correcting various classes of CFTR mutations.
- To explore genotype-phenotype correlations for guiding CF treatment approaches.
Main Methods:
- Classification of CFTR mutations into five classes based on defect type (e.g., premature stop codons, protein instability, impaired regulation, reduced conductance, reduced protein levels).
- Review of pharmacological agents and therapeutic strategies targeting each mutation class.
- Discussion of potential for gene therapy and genotype-phenotype correlations.
Main Results:
- Class I mutations (non-production) can be addressed by read-through drugs (e.g., aminoglycosides).
- Class II mutations (defective folding) may respond to chemical chaperones or gene-regulating drugs (e.g., butyrates).
- Class III (gating defects), Class IV (conductance defects), and Class V (reduced protein levels) mutations show potential for treatment with specific drugs like genistein, milrinone, or butyrates, alongside gene therapy.
Conclusions:
- Pharmacological treatments are being developed to target specific classes of CFTR mutations.
- Different mutation classes require distinct therapeutic strategies, including read-through agents, chaperones, and modulators.
- Personalized treatment approaches based on CFTR mutation type and genotype-phenotype correlations hold promise for CF management.