Hong Gwan Ui, Kim Nam Goo, Ro Jai Youl
Department of Pharmacology and Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746, South Korea.
Radiat Res. 2014 Apr;181(4):425-38. doi: 10.1667/RR13547.1. Epub 2014 Apr 10.
Allergic asthma is characterized by chronic airway remodeling, which is associated with the expression of extracellular matrix proteins (ECM) by TGF-β. However, to date there are no reports demonstrating that structural proteins are directly expressed in mast cells. This study aimed to investigate whether ECM proteins are expressed in mast cells activated with antigen/antibody reaction, and whether the resolution effects of irradiation or 8-oxo-dG may contribute to allergic asthma prevention. Bone marrow-derived mast cells (BMMCs) were activated with DNP-HSA/anti-DNP IgE antibody (act-BMMCs). C57BL/6 mice were sensitized and challenged with ovalbumin (OVA) to induce allergic asthma. Mice were treated orally with 8-oxo-dG or exposed to whole body irradiation (using (137)Cs gamma ray at a dose of 0.5 Gy) for three consecutive days 24 h after OVA challenge. Expression of extracellular matrix (ECM) proteins, TGF-β signaling molecules and NF-κB/AP-1 was determined in the BMMCs, bronchoalveolar lavage (BAL) cells or lung tissues using Western blot, polymerase chain reaction (PCR) and electrophoretic mobility shift assay (EMSA), respectively. Act-BMMCs increased expression of ECM proteins, TGF-β/TGF-β receptor I, TGF-β signaling molecules and cytokines; and increased both NF-κB and AP-1 activity. In addition, the population of mast cells; expression of mast cell markers, TGF-β signaling molecules, ECM proteins/amounts; OVA-specific serum IgE level; numbers of goblet cells; airway hyperresponsiveness; cytokines/chemokines were increased in BAL cells and lung tissues of OVA-challenged mice. All of the above end points were reduced by irradiation or 8-oxo-dG in vitro and in vivo, respectively. The data suggest that mast cells induce expression of ECM proteins through TGF-β produced in inflammatory cells of OVA mice and that post treatment of irradiation or 8-oxo-dG after OVA-challenge may reduce airway remodeling through down-regulating mast cell re-activation by TGF-β/Smad signals.
过敏性哮喘的特征是慢性气道重塑，这与转化生长因子-β（TGF-β）诱导的细胞外基质蛋白（ECM）表达有关。然而，迄今为止，尚无报道表明结构蛋白在肥大细胞中直接表达。本研究旨在调查ECM蛋白是否在通过抗原/抗体反应激活的肥大细胞中表达，以及辐射或8-氧代脱氧鸟苷（8-oxo-dG）的消退作用是否有助于预防过敏性哮喘。用二硝基苯基人血清白蛋白/抗二硝基苯基免疫球蛋白E抗体（act-BMMCs）激活骨髓来源的肥大细胞（BMMCs）。用卵清蛋白（OVA）致敏并攻击C57BL/6小鼠以诱导过敏性哮喘。在OVA攻击后24小时，小鼠连续三天口服8-oxo-dG或接受全身照射（使用剂量为0.5 Gy的¹³⁷Csγ射线）。分别使用蛋白质免疫印迹法、聚合酶链反应（PCR）和电泳迁移率变动分析（EMSA），测定BMMCs、支气管肺泡灌洗（BAL）细胞或肺组织中细胞外基质（ECM）蛋白、TGF-β信号分子以及核因子-κB/激活蛋白-1（NF-κB/AP-1）的表达。Act-BMMCs增加了ECM蛋白、TGF-β/TGF-β受体I、TGF-β信号分子和细胞因子的表达；并增加了NF-κB和AP-1的活性。此外，在OVA攻击小鼠的BAL细胞和肺组织中，肥大细胞数量、肥大细胞标志物表达、TGF-β信号分子、ECM蛋白/数量、OVA特异性血清IgE水平、杯状细胞数量、气道高反应性、细胞因子/趋化因子均增加。上述所有终点指标在体外和体内分别通过辐射或8-oxo-dG降低。数据表明，肥大细胞通过OVA小鼠炎症细胞产生的TGF-β诱导ECM蛋白表达，并且在OVA攻击后进行辐射或8-oxo-dG后处理可能通过下调TGF-β/Smad信号对肥大细胞的重新激活来减少气道重塑。
