Related Experiment Video
Updated: Dec 29, 2025
Metabolic Characterization of Polarized M1 and M2 Bone Marrow-derived Macrophages Using Real-time Extracellular Flux Analysis
Published on: November 28, 2015
N6-methyladenosine demethylase FTO promotes M1 and M2 macrophage activation
Xiaofei Gu1, Yiwen Zhang1, Di Li1
1Guanghua School of Stomatology & Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou 510055, China.
Abstract:
Macrophage polarization is the driving force of various inflammatory diseases, especially those involved in M1/M2 imbalance. N6-methyladenosine (m6A) is the most prevalent internal mRNA modification in eukaryotes that affects multiple biological processes, including those involved developmental arrest and immune response. However, the role of m6A in macrophage polarization remains unclear. This study found that FTO silencing significantly suppressed both M1 and M2 polarization. FTO depletion decreased the phosphorylation levels of IKKα/β, IκBα and p65 in the NF-κB signaling pathway. The expression of STAT1 was downregulated in M1-polarized macrophages while the expression of STAT6 and PPAR-γ decreased in M2 polarization after FTO knockdown. The actinomycin D experiments showed that FTO knockdown accelerated mRNA decay of STAT1 and PPAR-γ. Furthermore, the stability and expression of STAT1 and PPAR-γ mRNAs increased when the m6A reader YTHDF2 was silenced. In conclusion, our results suggest that FTO knockdown inhibits the NF-κB signaling pathway and reduces the mRNA stability of STAT1 and PPAR-γ via YTHDF2 involvement, thereby impeding macrophage activation. These findings indicated a previously unrecognized link between FTO and macrophage polarization and might open new avenues for research into the molecular mechanisms of macrophage polarization-related diseases.
Insights
FTO silencing inhibits macrophage polarization by impacting NF-κB signaling and mRNA stability of key genes like STAT1 and PPAR-γ, suggesting a novel link for inflammatory disease research.
Area of Science:
- Immunology
- Epigenetics
- Molecular Biology
Background:
- Macrophage polarization (M1/M2) is crucial in inflammatory diseases.
- N6-methyladenosine (m6A) is a key mRNA modification impacting biological processes.
- The role of m6A in macrophage polarization is not well understood.
Purpose of the Study:
- To investigate the role of FTO (an m6A demethylase) in macrophage polarization.
- To elucidate the molecular mechanisms by which FTO influences macrophage polarization.
Main Methods:
- Silencing of FTO in macrophages.
- Analysis of NF-κB signaling pathway components (IKKα/β, IκBα, p65).
- Assessment of STAT1, STAT6, and PPAR-γ expression.
- mRNA decay assays using actinomycin D.
- Investigation of the m6A reader YTHDF2.
Main Results:
- FTO silencing suppressed both M1 and M2 macrophage polarization.
- FTO depletion reduced NF-κB pathway phosphorylation.
- STAT1 expression decreased in M1, while STAT6 and PPAR-γ decreased in M2 macrophages upon FTO knockdown.
- FTO knockdown accelerated STAT1 and PPAR-γ mRNA decay.
- Silencing YTHDF2 increased STAT1 and PPAR-γ mRNA stability and expression.
Conclusions:
- FTO knockdown inhibits macrophage activation by suppressing the NF-κB pathway.
- FTO influences macrophage polarization partly through YTHDF2-mediated regulation of STAT1 and PPAR-γ mRNA stability.
- This study reveals a novel connection between FTO and macrophage polarization, offering potential therapeutic targets for related diseases.
