Lactoferrin Efficiently Counteracts the Inflammation-Induced Changes of the Iron Homeostasis System in Macrophages.
Lactoferrin Efficiently Counteracts the Inflammation-Induced Changes of the Iron Homeostasis System in Macrophages.
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DOI：
10.3389/fimmu.2017.00705
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发表时间：
2017
影响因子：
7.3
通讯作者：
Valenti P
中科院分区：
文献类型：
--
作者：
Cutone A;Rosa L;Lepanto MS;Scotti MJ;Berlutti F;Bonaccorsi di Patti MC;Musci G;Valenti P
人乳铁蛋白（Human lactoferrin，hLf）是一种分子量为80 kDa的多功能铁结合阳离子糖蛋白，在炎症过程中由外分泌腺和中性粒细胞组成性分泌。hLf被认为是宿主免疫防御系统中的关键元件。用牛Lf（bLf）进行体外和体内实验，bLf与hLf具有高度序列同源性和相同的功能，包括抗炎活性。在此，在通过用10 pg/ml LPS和20 ng/ml IFN-γ的混合物刺激获得的“纯”M1人巨噬细胞中，以及在用高剂量LPS（1 μg/ml）攻击的更异质的巨噬细胞群体中，bLf对参与铁和炎性稳态的主要蛋白质的表达的影响，所述主要蛋白质即膜铁转运蛋白（Fpn）、膜结合铜蓝蛋白（Cp）、已经研究了细胞溶质铁蛋白（Ftn）、转铁蛋白受体1和细胞因子。炎症处理后IL-6和IL-1β细胞因子的增加与胞质Ftn的上调和Fpn、膜结合Cp和转铁蛋白受体1的下调相关。所有这些变化都参与细胞内铁过载，这是一种非常不安全的状况，导致体内宿主对感染的易感性增加，以及血液中的铁缺乏和炎症性贫血。因此，对抗炎症状态的持续性以重新平衡组织/分泌物和血液之间的铁水平至关重要。此外，在用高剂量LPS处理的细胞中，TNF-α细胞因子IL-10的水平增加。相反，当使用LPS/IFN-γ混合物时，IL-10降低，这表明在我们的巨噬细胞模型中，只有由LPS高剂量触发的炎症才能启动抗炎反应。在这里，我们证明，bLf，当包括在培养基中，显着减少IL-6和IL-1β的生产，并有效地防止Fpn的变化，膜结合Cp，胞质Ftn，转铁蛋白受体1在“纯”M1巨噬细胞，以及在更异质的巨噬细胞群体。此外，由LPS/IFN-γ混合物诱导的IL-10的降低被牛乳铁蛋白抵消。几种能够调节巨噬细胞表型的药物正在成为治疗炎症的有吸引力的分子，在这个意义上，牛乳铁蛋白也不例外。
Human lactoferrin (hLf), an 80-kDa multifunctional iron-binding cationic glycoprotein, is constitutively secreted by exocrine glands and by neutrophils during inflammation. hLf is recognized as a key element in the host immune defense system. The in vitro and in vivo experiments are carried out with bovine Lf (bLf), which shares high sequence homology and identical functions with hLf, including anti-inflammatory activity. Here, in “pure” M1 human macrophages, obtained by stimulation with a mixture of 10 pg/ml LPS and 20 ng/ml IFN-γ, as well as in a more heterogeneous macrophage population, challenged with high-dose of LPS (1 µg/ml), the effect of bLf on the expression of the main proteins involved in iron and inflammatory homeostasis, namely ferroportin (Fpn), membrane-bound ceruloplasmin (Cp), cytosolic ferritin (Ftn), transferrin receptor 1, and cytokines has been investigated. The increase of IL-6 and IL-1β cytokines, following the inflammatory treatments, is associated with both upregulation of cytosolic Ftn and downregulation of Fpn, membrane-bound Cp, and transferrin receptor 1. All these changes take part into intracellular iron overload, a very unsafe condition leading in vivo to higher host susceptibility to infections as well as iron deficiency in the blood and anemia of inflammation. It is, therefore, of utmost importance to counteract the persistence of the inflammatory status to rebalance iron levels between tissues/secretions and blood. Moreover, levels of the antiinflammatory cytokine IL-10 were increased in cells treated with high doses of LPS. Conversely, IL-10 decreased when the LPS/IFN-γ mix was used, suggesting that only the inflammation triggered by LPS high doses can switch on an anti-inflammatory response in our macrophagic model. Here, we demonstrate that bLf, when included in the culture medium, significantly reduced IL-6 and IL-1β production and efficiently prevented the changes of Fpn, membrane-bound Cp, cytosolic Ftn, and transferrin receptor 1 in “pure” M1 macrophages, as well as in the more heterogeneous macrophage population. In addition, the decrease of IL-10 induced by the LPS/IFN-γ mix was counteracted by bovine lactoferrin. Several drugs capable of modulating macrophagic phenotypes are emerging as attractive molecules for treating inflammation, and in this sense, bovine lactoferrin is no exception.