Mechanisms underlying dilated cardiomyopathy associated with FKBP12 deficiency

Area of Science:

• Cardiology
• Molecular Biology
• Genetics

Background:

• Dilated cardiomyopathy (DCM) is a prevalent heart condition with genetic heterogeneity, affecting cardiac contractility.
• The role of FK506-binding protein FKBP12 in cardiac muscle function is not well understood, despite its known role in skeletal muscle ryanodine receptor regulation.

Purpose of the Study:

• To investigate the specific role of FKBP12 in cardiac function and its potential involvement in the pathogenesis of DCM.
• To determine the impact of FKBP12 deficiency on cardiac remodeling, oxidative stress, and calcium handling in the heart.

Main Methods:

• Generation of conditional mouse models with FKBP12 deficiency using Cre-lox technology driven by cardiac-specific promoters (αMHC and MCK).
• Analysis of cardiac function, histology, protein expression, and sarcoplasmic reticulum Ca2+ leak in adult mice with FKBP12 deletion at different embryonic stages.

Main Results:

• Conditional deletion of FKBP12 in adult hearts did not cause significant cardiac dysfunction.
• Early embryonic deletion of FKBP12 (αMHC-Cre) led to progressive DCM, increased cardiac oxidative stress, altered expression of cardiac remodeling proteins, and sarcoplasmic reticulum Ca2+ leak.
• FKBP12 deficiency during early development, but not later, resulted in significant cardiac pathology.

Conclusions:

• FKBP12 plays a critical role in embryonic cardiac muscle development and function.
• Early developmental deficiency of FKBP12 leads to cardiac remodeling and progressive DCM in adult hearts.
• These findings suggest FKBP12 as a potential therapeutic target for preventing or treating DCM associated with early developmental defects.