m6A 调控因子表达谱分析揭示 IGF2BP3 作为骨关节炎滑膜巨噬细胞的关键调节因子。

BACKGROUND: Disruption of N6 methyl adenosine (m6A) modulation hampers gene expression and cellular functions, leading to various illnesses. However, the role of m6A modification in osteoarthritis (OA) synovitis remains unclear. This study aimed to explore the expression patterns of m6A regulators in OA synovial cell clusters and identify key m6A regulators that mediate synovial macrophage phenotypes. METHODS: The expression patterns of m6A regulators in the OA synovium were illustrated by analyzing bulk RNA-seq data. Next, we built an OA LASSO-Cox regression prediction model to identify the core m6A regulators. Potential target genes of these m6A regulators were identified by analyzing data from the RM2target database. A molecular functional network based on core m6A regulators and their target genes was constructed using the STRING database. Single-cell RNA-seq data were collected to verify the effects of m6A regulators on synovial cell clusters. Conjoint analyses of bulk and single-cell RNA-seq data were performed to validate the correlation between m6A regulators, synovial clusters, and disease conditions. After IGF2BP3 was screened as a potential modulator in OA macrophages, the IGF2BP3 expression level was tested in OA synovium and macrophages, and its functions were further tested by overexpression and knockdown in vitro. RESULTS: OA synovium showed aberrant expression patterns of m6A regulators. Based on these regulators, we constructed a well-fitting OA prediction model comprising six factors (FTO, YTHDC1, METTL5, IGF2BP3, ZC3H13, and HNRNPC). The functional network indicated that these factors were closely associated with OA synovial phenotypic alterations. Among these regulators, the m6A reader IGF2BP3 was identified as a potential macrophage mediator. Finally, IGF2BP3 upregulation was verified in the OA synovium, which promoted macrophage M1 polarization and inflammation. CONCLUSIONS: Our findings revealed the functions of m6A regulators in OA synovium and highlighted the association between IGF2BP3 and enhanced M1 polarization and inflammation in OA macrophages, providing novel molecular targets for OA diagnosis and treatment.

背景：N6 甲基腺苷（m6A）修饰的破坏会阻碍基因表达和细胞功能，导致各种疾病。然而，m6A 修饰在骨关节炎（OA）滑膜炎中的作用尚不清楚。本研究旨在探讨 m6A 调节剂在 OA 滑膜细胞簇中的表达模式，并鉴定介导滑膜巨噬细胞表型的关键 m6A 调节剂。

方法：通过分析批量 RNA-seq 数据来描绘 OA 滑膜中 m6A 调节剂的表达模式。接下来，我们构建了一个 OA LASSO-Cox 回归预测模型，以鉴定核心 m6A 调节剂。通过分析 RM2target 数据库中的数据来鉴定这些 m6A 调节剂的潜在靶基因。使用 STRING 数据库构建基于核心 m6A 调节剂及其靶基因的分子功能网络。收集单细胞 RNA-seq 数据以验证 m6A 调节剂对滑膜细胞簇的影响。对批量和单细胞 RNA-seq 数据进行联合分析，以验证 m6A 调节剂、滑膜簇和疾病状况之间的相关性。筛选 IGF2BP3 作为 OA 巨噬细胞中的潜在调节剂后，在 OA 滑膜和巨噬细胞中检测 IGF2BP3 的表达水平，并通过体外过表达和敲低进一步测试其功能。

结果：OA 滑膜表现出 m6A 调节剂的异常表达模式。基于这些调节剂，我们构建了一个拟合良好的 OA 预测模型，包含六个因素（FTO、YTHDC1、METTL5、IGF2BP3、ZC3H13 和 HNRNPC）。功能网络表明，这些因素与 OA 滑膜表型改变密切相关。在这些调节剂中，m6A 阅读器 IGF2BP3 被鉴定为潜在的巨噬细胞介体。最后，在 OA 滑膜中验证了 IGF2BP3 的上调，这促进了巨噬细胞 M1 极化和炎症。

结论：我们的研究结果揭示了 m6A 调节剂在 OA 滑膜中的功能，并强调了 IGF2BP3 与 OA 巨噬细胞中增强的 M1 极化和炎症之间的关联，为 OA 的诊断和治疗提供了新的分子靶点。