哮喘联盟

   摘要
   背景：组蛋白乙酰化转移酶（HATs）和组蛋白去乙酰化酶（HDACs）能调控基因表达，但这些酶在哮喘炎症表型中活性的差异尚不清楚。我们假设中性粒细胞性哮喘（NA）可能与HAT活性增加和HDAC活性减少有关。
   目的：旨在研究总HAT/HDAC在健康受试者和哮喘患者分离的单核细胞和痰巨噬细胞中的活性和基因的表达。
   方法：外周血和诱导痰在哮喘成人（n=52）和健康受试者（n = 9）中被收集。统计痰炎症细胞数，根据痰嗜酸性粒细胞和嗜中性粒细胞的cut-off值> 3% 和 > 61%进行哮喘炎症表型分类。使用免疫磁珠细胞分离法分离外周血单核细胞（n = 61）和小部分哮喘患者中分离痰巨噬细胞（n = 14）。RNA和核蛋白被提取和量化。酶活性被使用荧光测定法评估且通过qPCR法评估EP300、KAT2B、CREBBP和HDACs 1、2 和 3 基因的表达。
   结果：血液单核细胞HAT和HDAC活性存在显著的反向关联（r = -0.58，P < 0.001）。与嗜酸粒细胞性哮喘相比，NA与血液单核细胞HAT酶活性增加（P = 0.02），HDAC活性减少（P = 0.03），HAT：HDAC 比值增加有关 (P < 0.01) 。从哮喘受试者或哮喘炎症表型的血液单核细胞中EP300，KAT2B，CREBBP或 HDACs 1， 2和 3的基因表型无差异。吸入糖皮质激素的使用，哮喘控制不佳或哮喘严重程度对HAT/HDAC 活性无影响。嗜酸粒细胞性哮喘与寡粒细胞性哮喘相比，痰巨噬细胞中KAT2B的表达增加。
   结论和临床指导意义：嗜中性粒细胞气道炎症与血液中单核细胞的HAT活性增加和HDAC活性减少有关。且进一步证明系统性损害与改变的嗜中性粒细胞哮喘炎症基因转录的特性有关。
 

（苏楠 审校）
Clin Exp Allergy. 2014 Jan;44(1):47-57. doi: 10.1111/cea.12168.

 

Activity and expression of histone acetylases and deacetylases in inflammatory phenotypes of asthma.
 

Gunawardhana LP, Gibson PG, Simpson JL, Powell H, Baines KJ.
 

Abstract
BACKGROUND: Histone acetyltransferases (HATs) and histone deacetylases (HDACs) regulate gene expression, yet differences in the activity of these enzymes in the inflammatory phenotypes of asthma are unknown. We hypothesized that neutrophilic asthma (NA) would be associated with increased HAT and decreased HDAC activity.
OBJECTIVE: To investigate total HAT/HDAC activity and gene expression in isolated blood monocytes and sputum macrophages from healthy and patients with asthma.
METHODS: Peripheral blood and induced sputum were collected from adults with asthma (n = 52) and healthy controls (n = 9). Sputum inflammatory cell counts were performed and asthma inflammatory phenotypes were classified according to sputum eosinophil and neutrophil cut-off's of > 3% and > 61% respectively. Peripheral blood monocytes were isolated (n = 61) and sputum macrophages were isolated from a subgroup of patients with asthma (n = 14), using immunomagnetic cell separation. RNA and nuclear proteins were extracted and quantified. Enzyme activity was assessed using fluorescent assays and gene expression of EP300, KAT2B, CREBBP, and HDACs 1, 2 and 3 were measured by qPCR.
RESULTS: There was a significant inverse association between blood monocyte HAT and HDAC activity (r = -0.58, P < 0.001). NA was associated with increased blood monocyte HAT enzyme activity (P = 0.02), decreased HDAC activity (P = 0.03), and increased HAT: HDAC ratio (P < 0.01) compared with eosinophilic asthma. There were no differences in gene expression of EP300, KAT2B, CREBBP, or HDACs 1, 2 and 3 in blood monocytes from subjects with asthma or inflammatory phenotypes of asthma. There was no effect of inhaled corticosteroid use, poor asthma control, or asthma severity on HAT/HDAC activities. Sputum macrophages had increased expression of KAT2B in eosinophilic compared with paucigranulocytic asthma.
CONCLUSIONS AND CLINICAL RELEVANCE: Neutrophilic airway inflammation is associated with increased HAT and reduced HDAC activity in blood monocytes, demonstrating further systemic manifestations relating to the altered inflammatory gene transcription profile of neutrophilic asthma.
 

Clin Exp Allergy. 2014 Jan;44(1):47-57. doi: 10.1111/cea.12168.