Stromal Cell-SLIT3/Cardiomyocyte-ROBO1 Axis Regulates Pressure Overload-Induced Cardiac Hypertrophy.

Area of Science:

• Cardiovascular Biology
• Molecular Cardiology
• Developmental Biology

Background:

• The secreted axon guidance molecule SLIT3 is expressed in the postnatal heart.
• Its role in postnatal cardiovascular function, particularly under stress, is largely unknown.
• This study investigates SLIT3's sources and function in the postnatal heart.

Purpose of the Study:

• Determine postnatal myocardial sources of SLIT3.
• Evaluate SLIT3's role in the cardiac response to pressure overload.
• Elucidate the SLIT3-ROBO1 signaling pathway in cardiac remodeling.

Main Methods:

• In vitro studies on cardiomyocytes and patient myocardial tissue.
• In vivo studies using SLIT3 and ROBO1 mutant mice subjected to transverse aortic constriction.
• Genetic manipulation including cell-specific knockouts of SLIT3 and ROBO1.

Main Results:

• SLIT3 transcription increased in human hearts with pressure overload.
• SLIT3 is secreted by cardiac fibroblasts and vascular mural cells, stimulating cardiomyocyte hypertrophy.
• SLIT3-ROBO1 signaling mediates hypertrophy and adverse cardiac remodeling in response to pressure overload.
• Genetic deletion of SLIT3 or ROBO1 attenuated hypertrophy and preserved cardiac function.

Conclusions:

• SLIT3 is a novel regulator of postnatal cardiac response to pressure overload.
• The SLIT3-ROBO1 axis plays a critical role in cardiac hypertrophy and remodeling.
• Targeting this pathway may offer therapeutic strategies for heart disease.