Controls of Nuclear Factor-Kappa B Signaling Activity by 5'-AMP-Activated Protein Kinase Activation With Examples in...

Area of Science:

• Cellular signaling and molecular biology
• Inflammation and hypoxia research
• Cancer cell biology

Background:

• Nuclear factor kappa B (NF-κB) signaling is crucial in inflammatory and hypoxia responses.
• Lipopolysaccharide (LPS) and hypoxia induce NF-κB, leading to downstream effects like cyclooxygenase induction.
• Posttranslational modifications of NF-κB, including phosphorylation, play a key role in regulating its activity.

Approach:

• Investigated the role of 5'-AMP-activated protein kinase (AMPK) activators, specifically 5'-aminoimidazole-4-carboxamide ribonucleotide (AICAR) and metformin.
• Examined the impact of AMPK activators on LPS/NF-κB and hypoxia/NF-κB-mediated cyclooxygenase induction.
• Analyzed the interplay between NF-κB phosphorylation and acetylation through an AMPK-dependent mechanism in T24 human bladder cancer cells.

Key Points:

• AICAR and metformin alleviate LPS- and hypoxia-induced NF-κB effects via AMPK activation.
• AMPK regulates cyclooxygenase induction by modulating NF-κB phosphorylation and acetylation.
• These regulatory interactions were observed in a human bladder cancer cell line (T24).

Conclusions:

• AMPK acts as a key regulator of NF-κB induction under inflammatory and hypoxia conditions.
• Differential posttranslational modification of NF-κB (phosphorylation and acetylation) is central to AMPK's regulatory role.
• Findings provide a deeper understanding of molecular mechanisms underlying inflammation, hypoxia, and cancer cell signaling.