Cardiac-Specific Cre Induces Age-Dependent Dilated Cardiomyopathy (DCM) in Mice

Area of Science:

• Genetics
• Cardiovascular Biology
• Molecular Biology

Background:

• The Cre-lox system enables temporal and spatial gene manipulation in mice.
• Unregulated Cre recombinase expression can lead to detrimental DNA damage and health consequences.
• Previous studies reported nonlethal hypertrophic cardiomyopathy (HCM) in aging alphaMHC-cre mice.

Purpose of the Study:

• To investigate the cardiac pathology and lethality observed in alphaMHC-cre mice.
• To determine the underlying molecular mechanisms of the observed cardiac phenotype.
• To caution researchers on the interpretation of gene function studies using the alphaMHC-cre model.

Main Methods:

• Utilized alphaMHC-cre mouse model.
• Performed echocardiography and histology for cardiac assessment.
• Conducted molecular analysis to examine DNA damage response pathways.

Main Results:

• Observed complete lethality in alphaMHC-cre mice by 11 months of age.
• Echocardiography and histology revealed dilated cardiomyopathy (DCM) by seven months.
• Molecular analysis indicated a DNA damage response with altered p38, JNK, p53, and Bax expression, leading to myocyte death and fibrosis.

Conclusions:

• The alphaMHC-cre driver itself can induce a lethal, age-dependent DCM.
• The observed phenotype is linked to DNA damage response pathways and myocyte apoptosis.
• Researchers must exercise caution when interpreting results from studies using the alphaMHC-cre mouse model due to potential Cre-induced toxicity.