Copper activates the NF-kappaB pathway in vivo

Area of Science:

• Biochemistry
• Toxicology
• Molecular Biology

Background:

• Intravenous copper administration in rats induces nitric oxide synthase (NOS-II).
• Copper's role in activating transcription factors and inflammatory pathways requires further elucidation.

Purpose of the Study:

• To investigate copper-induced activation of the transcription factor NF-kappaB.
• To determine the role of oxidative stress in copper-mediated inflammatory responses.
• To identify molecular mechanisms underlying copper-induced inflammation.

Main Methods:

• Electrophoretic mobility shift assays (EMSA) to assess NF-kappaB activation.
• Administration of copper-histidine complex and the antioxidant tempol in rat models.
• Histological analysis, nitrotyrosine formation, and measurement of TNF-alpha, NOS-II, and nitrites.

Main Results:

• Copper activates NF-kappaB in rat liver and lung tissues, involving p50/p65 dimers and higher aggregates.
• Copper-induced effects, including histological changes and inflammatory markers, are mediated by oxidative stress and prevented by tempol.
• Copper also induces COX-2, an NF-kappaB-dependent gene, an effect reduced by tempol.

Conclusions:

• Copper-induced NF-kappaB activation and subsequent inflammation are mediated by reactive oxygen species (ROS).
• Hypercupremia may initiate inflammation through ROS production and NF-kappaB activation.
• Antioxidant intervention can mitigate copper-induced inflammatory responses.