Department of Immunology, University of Debrecen, Egyetem tér 1, Debrecen 4032, Hungary.
CycloLab Cyclodextrin Research & Development Laboratory Ltd., Illatos út 7, Budapest 1097, Hungary.
Beilstein J Org Chem. 2014 Dec 30;10:3152-60. doi: 10.3762/bjoc.10.332. eCollection 2014.
The n-3 fatty acids are not produced by mammals, although they are essential for hormone synthesis and maintenance of cell membrane structure and integrity. They have recently been shown to inhibit inflammatory reactions and also emerged as potential treatment options for inflammatory diseases, such as rheumatoid arthritis, asthma and inflammatory bowel diseases. Dendritic cells (DC) play a central role in the regulation of both innate and adaptive immunity and upon inflammatory signals they produce various soluble factors among them cytokines and chemokines that act as inflammatory or regulatory mediators. In this study we monitored the effects of α-linoleic acid, eicosapentaenoic acid and docosahexaenoic acid solubilized in a dimethyl sulfoxide (DMSO)/ethanol 1:1 mixture or as complexed by randomly methylated α-cyclodextrin (RAMEA) on the inflammatory response of human monocyte-derived dendritic cells (moDC). The use of RAMEA for enhancing aqueous solubility of n-3 fatty acids has the unambiguous advantage over applying RAMEB (the β-cyclodextrin analog), since there is no interaction with cell membrane cholesterol. In vitro differentiated moDC were left untreated or were stimulated by bacterial lipopolysaccharide and polyinosinic:polycytidylic acid, mimicking bacterial and viral infections, respectively. The response of unstimulated and activated moDC to n-3 fatty acid treatment was tested by measuring the cell surface expression of CD1a used as a phenotypic and CD83 as an activation marker of inflammatory moDC differentiation and activation by using flow cytometry. Monocyte-derived DC activation was also monitored by the secretion level of the pro- and anti-inflammatory cytokines IL-1β, TNF-α, IL-6, IL-10 and IL-12, respectively. We found that RAMEA-complexed n-3 fatty acids reduced the expression of CD1a protein in both LPS and Poly(I:C) stimulated moDC significantly, but most efficiently by eicosapentaenic acid, while no significant change in the expression of CD83 protein was observed. The production of IL-6 by LPS-activated moDC was also reduced significantly when eicosapentaenic acid was added as a RAMEA complex as compared to its DMSO-solubilized form or to the other two n-3 fatty acids either complexed or not. Based on these results n-3 fatty acids solubilized by RAMEA provide with a new tool for optimizing the anti-inflammatory effects of n-3 fatty acids exerted on human moDC and mediated through the GP120 receptor without interfering with the cell membrane structure.
n-3 脂肪酸不能由哺乳动物产生，尽管它们对激素合成和细胞膜结构与完整性的维持是必不可少的。最近发现它们能抑制炎症反应，并且可能成为炎症性疾病（如类风湿关节炎、哮喘和炎症性肠病）的潜在治疗选择。树突状细胞（DC）在先天免疫和适应性免疫的调节中发挥核心作用，在炎症信号的作用下，它们产生各种可溶性因子，其中包括细胞因子和趋化因子，它们作为炎症或调节介质发挥作用。在这项研究中，我们监测了 α-亚麻酸、二十碳五烯酸和二十二碳六烯酸在二甲基亚砜（DMSO）/乙醇 1:1 混合物中溶解或与随机甲基化 α-环糊精（RAMEA）复合的情况下对人单核细胞来源的树突状细胞（moDC）炎症反应的影响。与应用 RAMEB（β-环糊精类似物）相比，使用 RAMEA 增强 n-3 脂肪酸的水溶性具有明显的优势，因为它与细胞膜胆固醇没有相互作用。体外分化的 moDC 未经处理或用细菌脂多糖和聚肌苷酸：聚胞苷酸刺激，分别模拟细菌和病毒感染。通过流式细胞术测量作为炎症 moDC 分化和激活的表型和 CD83 标志物的细胞表面表达，测试未刺激和激活的 moDC 对 n-3 脂肪酸处理的反应。通过分别测量促炎和抗炎细胞因子 IL-1β、TNF-α、IL-6、IL-10 和 IL-12 的分泌水平，监测单核细胞来源的 DC 激活。我们发现，RAMEA 复合的 n-3 脂肪酸显著降低 LPS 和 Poly(I:C) 刺激的 moDC 中 CD1a 蛋白的表达，但以二十碳五烯酸的效果最为显著，而 CD83 蛋白的表达没有明显变化。与其 DMSO 溶解形式或其他两种 n-3 脂肪酸（无论是复合的还是非复合的）相比，当添加到 RAMEA 复合物中时，LPS 激活的 moDC 产生的 IL-6 也显著减少。基于这些结果，RAMEA 溶解的 n-3 脂肪酸为优化 n-3 脂肪酸对人 moDC 的抗炎作用提供了一种新工具，这种作用是通过 GP120 受体介导的，而不会干扰细胞膜结构。
