Division of Nutritional Sciences, University of Illinois Urbana Champaign, Urbana, IL, United States.
Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD, United States.
Biochim Biophys Acta Mol Cell Biol Lipids. 2023 Apr;1868(4):159291. doi: 10.1016/j.bbalip.2023.159291. Epub 2023 Feb 6.
Retinoic acid possesses potent immunomodulatory properties in various cell types, including macrophages. In this study, we first investigated the effects at the transcriptional and functional levels of exogenous retinoic acid in murine bone marrow-derived macrophages (BMDMs) in the presence or absence of interleukin 4 (IL4), a cytokine with potent anti-inflammatory properties. We examined the effect of IL4 on vitamin A homeostasis in macrophages by quantifying retinoid synthesis and secretion. Our RNAseq data show that exogenous retinoic acid synergizes with IL4 to regulate anti-inflammatory pathways such as oxidative phosphorylation and phagocytosis. Efferocytosis and lysosomal degradation assays validated gene expression changes at the functional level. IL4 treatment altered the expression of several genes involved in vitamin A transport and conversion to retinoic acid. Radiolabeling experiments and mass spectrometry assays revealed that IL4 stimulates retinoic acid production and secretion in a signal transducer and activator of transcription 6 (STAT6)-dependent manner. In summary, our studies highlight the key role of exogenous and endogenous retinoic acid in shaping the anti-inflammatory response of macrophages.
维甲酸在包括巨噬细胞在内的各种细胞类型中具有强大的免疫调节特性。在这项研究中,我们首先研究了外源性维甲酸在存在或不存在白细胞介素 4(IL4)的情况下对鼠骨髓来源的巨噬细胞(BMDM)的转录和功能水平的影响,白细胞介素 4 是一种具有强大抗炎特性的细胞因子。我们通过定量分析类视黄醇的合成和分泌来研究 IL4 对巨噬细胞中维生素 A 动态平衡的影响。我们的 RNAseq 数据表明,外源性维甲酸与 IL4 协同作用,调节抗炎途径,如氧化磷酸化和吞噬作用。胞饮作用和溶酶体降解测定验证了功能水平上的基因表达变化。IL4 处理改变了几个参与维生素 A 转运和转化为维甲酸的基因的表达。放射性标记实验和质谱分析表明,IL4 以信号转导和转录激活因子 6(STAT6)依赖性方式刺激维甲酸的产生和分泌。总之,我们的研究强调了外源性和内源性维甲酸在塑造巨噬细胞抗炎反应中的关键作用。