ZnO NPs Attenuate LPS-Induced Inflammation in RAW264.7 Macrophages by Inhibiting NF-κB and JAK1-STAT1/STAT3 Pathways...

Area of Science:

• Nanomedicine and Immunology
• Cellular and Molecular Biology

Background:

• Macrophage-driven inflammatory signaling is central to various diseases.
• Zinc oxide nanoparticles (ZnO NPs) show anti-inflammatory potential, but mechanisms are unclear.
• This study explores ZnO NP effects on lipopolysaccharide (LPS)-induced inflammation in macrophages.

Purpose of the Study:

• To elucidate the molecular mechanisms underlying the anti-inflammatory effects of ZnO NPs.
• To investigate ZnO NP modulation of LPS-induced inflammatory pathways in RAW264.7 macrophages.

Main Methods:

• Characterization of ZnO NP size via SEM and cytotoxicity assessment.
• Treatment of RAW264.7 cells with varying ZnO NP concentrations followed by LPS stimulation.
• Analysis of pro-inflammatory (TNF-α, IL-1β, IL-6, iNOS, COX-2) and anti-inflammatory (Arg-1) factors, nitric oxide (NO), reactive oxygen species (ROS), and gene expression via qRT-PCR, ELISA, Western blot, and RNA-sequencing.

Main Results:

• ZnO NPs significantly reduced LPS-induced NO and pro-inflammatory cytokine production while enhancing Arg-1 expression.
• RNA-sequencing revealed 2638 differentially expressed genes in response to ZnO NP treatment.
• Mechanistically, ZnO NPs inhibited NF-κB activation (by reducing IκB-α degradation and p65 translocation) and suppressed JAK1-STAT1/3 signaling, alongside decreasing ROS production.

Conclusions:

• ZnO NPs effectively mitigate LPS-induced inflammation in macrophages by targeting NF-κB and JAK1-STAT1/3 pathways.
• Reduction of ROS is another key mechanism contributing to ZnO NP's anti-inflammatory action.
• These findings highlight the therapeutic potential of ZnO NPs for inflammatory disorders involving macrophage dysregulation.