METTL14/YTHDF2 m6A Axis Protects Against M2 Macrophage Polarization in Endometriosis by Regulating KLF4 Stability

Endometriosis (EMs) is a chronic inflammatory disorder featured by infertility and pain. The role of N6-methyladenosine (m6A) in EMs has been evidenced. This study investigated the molecular mechanism of METTL14-m6A-KLF4 modulating macrophage polarization in EMs. RT-qPCR assay was conducted to test METTL14 levels in tissues and cells and the relative mRNA levels of M2 (Arg-1, Fizz1) and M1 (iNOS, IL-1β) factors in the supernatant after co-culture of macrophages with normal endometrial stromal cells (nESCs) or ectopic endometrial stromal cells (eESCs). CD206 and CD86 expression, as well as Arg-1, IL-10, and IL-4 levels, were assessed. Meanwhile, the relationship between METTL14 and the m6A modification of KLF4 was analyzed. Additionally, the effect of KLF4-activated M2 macrophages on in vitro ESC progression was observed. Cellular and tissue METTL14 was under-expressed in EMs. METTL14 expression might be related to macrophage M2 polarization. Co-culture of eESCs overexpressing METTL14 and macrophages downregulated Arg-1, Fizz1, CD206, IL-10, and IL-4 levels. Mechanistically, METTL14 could mediate KLF4 m6A modification through the m6A reading protein YTHDF2. KLF4 overexpression could nullify METTL14 re-expression-repressed M2 macrophage polarization. In addition, KLF4-activated M2 macrophages accelerated the proliferation and migration of ESCs in vitro. METTL14-m6A-KLF4 regulated macrophage polarization in EMs. Similar content being viewed by others Data Availability All data generated or analyzed during this study are included in this article. Further enquiries can be directed to the corresponding author.

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Corresponding author Ethics declarations Ethics Approval and Consent to Participate The study was approved by the academic ethics committee of Affiliated Hospital of Zunyi Medical University. Participants were informed of the research objectives and signed informed consent forms. All procedures involving human participants complied with the Declaration of Helsinki (revised in 2013). Consent for Publication Not applicable. Competing interests The authors declare no competing interests. Additional information Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Rights and permissions Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law. About this article Cite this article Li, L., Wang, X., Wu, Y. et al. METTL14/YTHDF2 m6A Axis Protects Against M2 Macrophage Polarization in Endometriosis by Regulating KLF4 Stability. Appl Biochem Biotechnol 197, 5535–5551 (2025). https://doi.org/10.1007/s12010-025-05290-5 Accepted: Published: Version of record: Issue date: DOI: https://doi.org/10.1007/s12010-025-05290-5