A G542X cystic fibrosis mouse model for examining nonsense mutation directed therapies

Area of Science:

• Biomedical Research
• Genetics
• Disease Modeling

Background:

• Nonsense mutations in the CFTR gene affect 10% of cystic fibrosis (CF) patients, leading to non-functional CFTR protein.
• Current animal models lack endogenous nonsense mutations, hindering the development of targeted therapies.

Purpose of the Study:

• To create a novel CF mouse model with a G542X nonsense mutation in the Cftr gene.
• To establish a preclinical tool for evaluating therapies for CF nonsense mutations.

Main Methods:

• CRISPR/Cas9 gene editing was employed to introduce the G542X nonsense mutation into the endogenous Cftr locus in mice.
• Phenotypic characterization of the G542X mouse model, including CFTR expression, function, and disease manifestations.
• In vitro assessment of CFTR restoration using G418, an aminoglycoside, in intestinal organoids derived from the G542X model.

Main Results:

• The G542X mouse model exhibits reduced Cftr mRNA levels and a complete absence of CFTR function.
• The model displays characteristic CF manifestations, including reduced growth and intestinal obstruction.
• Treatment with G418 demonstrated CFTR restoration in G542X intestinal organoids, indicating translational readthrough efficacy.

Conclusions:

• The G542X mouse model is a valuable preclinical tool for studying CF caused by nonsense mutations.
• This model will facilitate the identification and in vivo assessment of novel therapies targeting CFTR nonsense mutations.