Attenuated SAG expression exacerbates 4-hydroxy-2-nonenal-induced apoptosis and hypertrophy of H9c2 cardiomyocytes

Area of Science:

• Cardiovascular Science
• Molecular Biology
• Cellular Biology

Background:

• Oxidative stress, driven by reactive oxygen species (ROS), causes significant myocardial damage, including apoptosis, hypertrophy, and dysfunction.
• The sensitive to apoptosis gene (SAG) protein, a RING finger protein, confers protection against oxidative stress-induced apoptosis in various cell types.
• 4-hydroxy-2-nonenal (HNE), a lipid peroxidation product, is a major contributor to cellular damage during oxidative stress.

Purpose of the Study:

• To investigate the role of SAG in protecting cardiomyocytes against HNE-induced oxidative stress.
• To elucidate the mechanisms by which SAG influences cellular redox status, mitochondrial function, and oxidative damage.

Main Methods:

• Utilized small interfering RNA (siRNA) to specifically attenuate SAG expression in H9c2 clonal myoblastic cells.
• Assessed HNE-induced apoptosis and hypertrophy in cells with suppressed SAG expression.
• Analyzed changes in cellular redox status, mitochondrial function, and oxidative damage.

Main Results:

• siRNA-mediated knockdown of SAG significantly exacerbated HNE-induced apoptosis and hypertrophy in H9c2 cells.
• Suppression of SAG expression led to altered cellular redox status, impaired mitochondrial function, and increased cellular oxidative damage.
• These findings indicate that SAG plays a crucial role in mitigating HNE-induced cellular injury.

Conclusions:

• SAG protein is essential for maintaining the redox balance in cardiomyocytes and protecting them from oxidative damage.
• Suppression of SAG enhances susceptibility to HNE-induced apoptosis and hypertrophy, highlighting its protective role.
• SAG represents a potential therapeutic target for preventing or treating cardiovascular diseases associated with oxidative stress.