Nrf2 regulates PU.1 expression and activity in the alveolar macrophage.
Nrf2 regulates PU.1 expression and activity in the alveolar macrophage.
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DOI：
10.1152/ajplung.00355.2014
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发表时间：
2015-05
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影响因子：
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通讯作者：
B. Staitieh;X. Fan;W. Neveu;D. Guidot
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文献类型：
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作者：
B. Staitieh;X. Fan;W. Neveu;D. Guidot
肺泡巨噬细胞（AM）的免疫功能依赖于粒细胞巨噬细胞集落刺激因子（GM-CSF）对转录因子PU.1的激活。我们已经确定，慢性酒精摄入通过未知的锌依赖性机制抑制PU.1信号传导;具体而言，虽然PU.1是一种锌依赖性转录因子，但锌治疗逆转了酒精介导的PU.1信号传导抑制。核因子（红细胞衍生2）样2（Nrf 2），锌依赖性碱性亮氨酸拉链蛋白的抗氧化防御必不可少的，也受到慢性酒精摄入和锌治疗增强。我们假设PU.1对锌处理的反应可能是由于Nrf 2对PU.1的作用。我们首先在大鼠AM细胞系（NR 8383）上进行了Nrf 2/PU.1蛋白共沉淀，没有发现蛋白质-蛋白质相互作用的证据。然后，我们通过染色质免疫沉淀发现了Nrf 2与PU.1启动子区域结合增加的证据。接下来，我们使用萝卜硫素或过表达载体激活Nrf 2，并使用沉默RNA抑制Nrf 2，以确定Nrf 2是否可以主动调节PU。Nrf 2激活增加了这两种因子的蛋白表达以及它们各自的下游效应物NAD（P）H脱氢酶[醌] 1（NQO 1）和分化抗原簇-14（CD 14）的基因表达。相反，Nrf 2沉默降低了两种蛋白质的表达，以及其效应子的基因表达。在原代大鼠AM中激活和抑制Nrf 2导致类似的效果。总之，这些发现表明，Nrf 2调节PU.1的表达和活性，并且抗氧化反应和免疫激活在AM内协调调节。
Alveolar macrophage (AM) immune function depends on the activation of the transcription factor PU.1 by granulocyte macrophage colony-stimulating factor. We have determined that chronic alcohol ingestion dampens PU.1 signaling via an unknown zinc-dependent mechanism; specifically, although PU.1 is not known to be a zinc-dependent transcription factor, zinc treatment reversed alcohol-mediated dampening of PU.1 signaling. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2), a zinc-dependent basic leucine zipper protein essential for antioxidant defenses, is also impaired by chronic alcohol ingestion and enhanced by zinc treatment. We hypothesized that the response of PU.1 to zinc treatment may result from the action of Nrf2 on PU.1. We first performed Nrf2/PU.1 protein coimmunoprecipitation on a rat AM cell line (NR8383) and found no evidence of protein-protein interactions. We then found evidence of increased Nrf2 binding to the PU.1 promoter region by chromatin immunoprecipitation. We next activated Nrf2 using either sulforaphane or an overexpression vector and inhibited Nrf2 with silencing RNA to determine whether Nrf2 could actively regulate PU.1. Nrf2 activation increased protein expression of both factors as well as gene expression of their respective downstream effectors, NAD(P)H dehydrogenase[quinone] 1 (NQO1) and cluster of differentiation antigen-14 (CD14). In contrast, Nrf2 silencing decreased the expression of both proteins, as well as gene expression of their effectors. Activating and inhibiting Nrf2 in primary rat AMs resulted in similar effects. Taken together, these findings suggest that Nrf2 regulates the expression and activity of PU.1 and that antioxidant response and immune activation are coordinately regulated within the AM.