Selenium: a key element that controls NF-kappa B activation and I kappa B alpha half life

Area of Science:

• Cellular biology
• Molecular biology
• Biochemistry

Background:

• Hydrogen peroxide (H2O2) triggers NF-kappa B nuclear translocation in mammalian cells.
• NF-kappa B binding to DNA regulates numerous genes.
• Selenium's role in cellular defense mechanisms is under investigation.

Purpose of the Study:

• To investigate the role of selenium in NF-kappa B activation.
• To analyze the effect of glutathione peroxidase (GPx) activity on NF-kappa B signaling.
• To determine selenium's impact on reactive oxygen species (ROS) and NF-kappa B pathway.

Main Methods:

• Utilized human T47D cells overexpressing glutathione peroxidase.
• Exposed cells to hydrogen peroxide (H2O2).
• Assessed intracellular ROS levels, NF-kappa B activation, p50 subunit translocation, and I kappa B alpha degradation.

Main Results:

• Overexpression of active glutathione peroxidase led to seleno-dependent reduction in intracellular ROS.
• NF-kappa B activation was decreased in cells with higher GPx activity.
• Inhibition of NF-kappa B (p50) nuclear translocation and absence of I kappa B alpha degradation were observed.
• Overexpression of active GPx doubled the half-life of I kappa B alpha in untreated cells.

Conclusions:

• Selenium modulates glutathione peroxidase activity, inhibiting NF-kappa B activation.
• Selenium plays a crucial role in cellular defense against oxidative stress-induced signaling.
• Selenium up-regulates the normal half-life of I kappa B alpha, contributing to the inhibition of NF-kappa B signaling.