Department of Pharmacology, Faculty of Pharmacy, Universidad de Sevilla, Seville, 41012, Spain.
Department of Pharmacology, Faculty of Pharmacy, Universidad de Sevilla, Seville, 41012, Spain.
Pharmacol Res. 2018 Feb;128:220-230. doi: 10.1016/j.phrs.2017.10.009. Epub 2017 Nov 10.
Oxylipins (OXLs) are bioactive molecules generated by the oxidation of fatty acids that promote the resolution of acute inflammation and prevent chronic inflammatory processes through molecular mechanisms that are not well known. We have previously reported the anti-inflammatory activity of microalgae-derived OXLs and OXL-containing biomass in two inflammatory bowel disease (IBD) models: 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced acute colitis and TNBS-induced recurrent colitis. In this study, we examined the in vitro anti-inflammatory mechanism of action of the most abundant OXLs isolated from Chlamydomonas debaryana (13S-HOTE and 13S-HODE) and Nannochloropsis gaditana (15S-HEPE). These OXLs decreased IL-1β and IL-6 pro-inflammatory cytokines production as well as iNOS and COX-2 expression levels in THP-1 macrophages. In addition, OXLs decreased IL-8 production in HT-29 colon cells, the major chemokine produced by these cells. The interaction of OXLs with NFκB and PPAR-γ signaling pathways was studied by confocal microscopy. In THP-1 macrophages and HT-29 colon cells, stimulated by LPS and TNFα respectively, a pre-treatment with 13S-HOTE, 13S-HODE and 15S-HEPE (100μM) resulted in a lower nuclear presence of NFκB in both cell lines. The study of the subcellular localization of PPAR-γ showed that the treatment of THP-1 and HT-29 cells with these OXLs caused the migration of PPAR-γ into the nucleus. Colocalization analysis of both transcription factors in LPS-stimulated THP-1 macrophages showed that the pre-treatment with 13S-HOTE, 13S-HODE or 15S-HEPE lowered nuclear colocalization similar to control value, and increased cytosolic localization above control level. These results indicate that these OXLs could act as agonist of PPAR-γ and consequently inhibit NFκB signaling pathway activation, thus lowering the production of inflammatory markers, highlighting the therapeutic potential of these OXLs in inflammatory diseases such as IBD.
氧化脂类（OXLs）是脂肪酸氧化生成的生物活性分子，通过尚未完全阐明的分子机制，促进急性炎症的消退，并防止慢性炎症过程。我们之前已经报道了源自微藻的 OXLs 和含有 OXLs 的生物质在两种炎症性肠病（IBD）模型中的抗炎活性：2,4,6-三硝基苯磺酸（TNBS）诱导的急性结肠炎和 TNBS 诱导的复发性结肠炎。在这项研究中，我们研究了从 Chlamydomonas debaryana（13S-HOTE 和 13S-HODE）和 Nannochloropsis gaditana（15S-HEPE）分离的最丰富的 OXL 的体外抗炎作用机制。这些 OXLs 降低了 THP-1 巨噬细胞中促炎细胞因子 IL-1β 和 IL-6 的产生以及 iNOS 和 COX-2 的表达水平。此外，OXLs 降低了 HT-29 结肠细胞中主要趋化因子 IL-8 的产生。通过共聚焦显微镜研究了 OXL 与 NFκB 和 PPAR-γ 信号通路的相互作用。在分别由 LPS 和 TNFα 刺激的 THP-1 巨噬细胞和 HT-29 结肠细胞中，用 13S-HOTE、13S-HODE 和 15S-HEPE（100μM）预处理会导致这两种细胞系中 NFκB 的核内存在降低。PPAR-γ 的亚细胞定位研究表明，用这些 OXL 处理 THP-1 和 HT-29 细胞会导致 PPAR-γ 迁移到细胞核中。在 LPS 刺激的 THP-1 巨噬细胞中对这两种转录因子的共定位分析表明，用 13S-HOTE、13S-HODE 或 15S-HEPE 预处理会降低核共定位，使其接近对照值，并使胞质定位高于对照水平。这些结果表明，这些 OXLs 可以作为 PPAR-γ 的激动剂，从而抑制 NFκB 信号通路的激活，从而降低炎症标志物的产生，突出了这些 OXLs 在炎症性疾病（如 IBD）中的治疗潜力。
