m6A Reader YTHDF2 Regulates LPS-Induced Inflammatory Response.

Area of Science:

• Molecular Biology
• Immunology
• Epigenetics

Background:

• N6-methyladenosine (m6A) is a key mRNA modification influencing biological processes.
• YTHDF2, an m6A-binding protein, regulates mRNA stability and localization.
• The role of YTHDF2 in inflammatory responses, particularly LPS-induced reactions, remains uncharacterized.

Purpose of the Study:

• To investigate the function of YTHDF2 in the inflammatory response of macrophages.
• To determine the effect of YTHDF2 on LPS-induced inflammatory mediator expression and signaling pathways.

Main Methods:

• Detected YTHDF2 expression in RAW 264.7 cells post-LPS stimulation.
• Performed YTHDF2 knockdown and assessed inflammatory cytokine (IL-6, TNF-α, IL-1β, IL-12) and signaling pathway (NF-κB, MAPK) activation.
• Utilized pathway inhibitors to confirm the role of specific signaling cascades.

Main Results:

• YTHDF2 expression was upregulated by LPS stimulation.
• YTHDF2 knockdown significantly increased LPS-induced IL-6, TNF-α, IL-1β, and IL-12 expression and NF-κB/MAPK pathway activation.
• Inhibitors of NF-κB, p38, and ERK pathways reversed the increased cytokine expression in YTHDF2-silenced cells.
• YTHDF2 depletion enhanced MAP2K4 and MAP4K4 mRNA expression and stability, activating MAPK and NF-κB signaling.

Conclusions:

• YTHDF2 knockdown promotes pro-inflammatory cytokine production by stabilizing MAP2K4 and MAP4K4 mRNAs.
• This stabilization activates MAPK and NF-κB signaling, exacerbating the inflammatory response in LPS-stimulated macrophages.
• YTHDF2 plays a critical role in regulating macrophage inflammatory responses.