Hyperhomocysteinemia regulated SCF expression in cultured cardiomyocytes via modulation of NF-κB activities

Area of Science:

• Cardiovascular Biology
• Molecular Cardiology
• Stem Cell Biology

Background:

• Hyperhomocysteinemia (HHcy) is a significant risk factor for coronary artery disease and myocardial infarction.
• Myocardial stem cell factor (SCF) plays a role in cardiac repair by mediating cardiac stem cell migration.
• The effect of HHcy on SCF expression in cardiomyocytes remains unclear.

Purpose of the Study:

• To investigate the impact of HHcy on SCF expression in cultured neonatal rat cardiomyocytes.
• To elucidate the role of nuclear factor-kappaB (NF-κB) signaling in HHcy-mediated SCF regulation.
• To understand the concentration-dependent effects of HHcy on cardiomyocyte function.

Main Methods:

• Primary neonatal rat cardiomyocytes were cultured and treated with varying concentrations of homocysteine (Hcy) (20, 50, 100 μM).
• SCF expression levels were measured following Hcy treatment.
• NF-κB activity was assessed, and the effect of an NF-κB inhibitor (N-acetylcysteine) was evaluated.

Main Results:

• Low to moderate Hcy concentrations (20-50 μM) significantly increased SCF expression, correlating with elevated NF-κB activity.
• Inhibition of NF-κB activity by N-acetylcysteine attenuated the Hcy-induced increase in SCF.
• High Hcy concentration (100 μM) markedly decreased SCF expression, accompanied by suppressed NF-κB activity.

Conclusions:

• HHcy regulates SCF expression in cardiomyocytes in a concentration-dependent manner.
• NF-κB signaling is a key mediator of HHcy's effect on SCF expression.
• HHcy may contribute to cardiovascular disease risk through direct detrimental effects on cardiomyocytes, beyond endothelial dysfunction.