1,25-二羟维生素D_3对于哮喘大鼠及其肺泡巨噬细胞中VDUP1/TRX的影响

The Role of 1, 25-dihydroxyvitamin D_3 in Regulating VDUP1/TRX for Asthma in a Rat Model

目的探讨1,25-二羟维生素D3(1,25-dihydroxyvitamin D3,1,25(OH)2D3)对哮喘大鼠支气管肺泡灌洗液(bronchoalveolar lavage fuluid,BALF)中维生素D上调蛋白1(vitamin D up-regulated protein 1,VDUP1)和硫氧还蛋白(thioredoxin,TRX)表达及气道炎症的影响。方法将28只Wistar大鼠随机分为4组,以卵白蛋白(ovalbumin,OVA)诱导哮喘发作,并给予1,25(OH)2D3和地塞米松干预,同时设对照组。测定BALF中IL-4和IL-10水平,细胞总数和肺组织病理变化。同时提取7只哮喘模型大鼠BALF中的巨噬细胞,体外给予1,25(OH)2D3干预。用逆转录-聚合酶链反应检测肺组织及BALF中巨噬细胞表达VDUP1和TRX的水平。结果 1,25(OH)2D3治疗组BALF中细胞总数及嗜酸粒细胞计数和IL-4水平降低,IL-10水平增高。肺组织及肺泡巨噬细胞中VDUP1和TRX表达增加。结论给予哮喘大鼠1,25(OH)2D3可抑制气道炎症,增加TRX和VDUP1的表达,两者可作为哮喘氧化应激的监测指标。

Objective To investigate the effect of 1,25-dihydroxyvitamin D3（1,25（OH）2D3） on airway inflammation and in regulating the expression of vitamin D up-regulated protein 1 （VDUP1） and thioredoxin （TRX） in the lungs and in alveolar macrophages of bronchoalveolar lavage fuluid （BALF）.Methods Twenty-eight healthy Wistar rats were randomly divided into four groups：normal control group, asthma group and two treatment groups. Asthma was induced in rats by sensitization and challenges with ovalbumin （OVA）. The first treated group was given oral calcitriol （0.25 μg/ d） 1 h before each challenge; The second treated group was injected with subcutaneous dexamethasone （300 μg） 1 h before each challenge; The level of IL-4 and IL-10,the inflammatory cell infiltration in BALF and histological changes were examined 24 h after the last antigen aerosol challenge. Alveolar macrophages were separated and cultured. 10-13, 10-10 and 10-8 mol/L 1,25（OH）2D3 was added to the medium. The mRNA level of VDUP1 and TRX in the lungs and alveolar macrophages of BALF was examined.Results Our findings demonstrate that 1,25（OH）2D3 reduces the airway inflammatory response in BALF. The level of IL-10 in BALF was increased in the 1,25（OH）2D3 treated groups while that of IL-4 was decreased in the same groups. The expression of VDUP1 and TRX in the lungs was increased in 1,25（OH）2D3 treated groups （P〈0.05）. The expression of VDUP1 and TRX mRNA levels were dose-dependently incrased in the presence of 10-13 ~10-8 mol/L 1,25（OH）2D3 in alveolar macrophage culture.Conclusions These findings collectively indicate that 1,25（OH）2D3 attenuates airway inflammatory response and increased the expression of IL-10 and the level of VDUP1 and TRX mRNA in treated groups, potentially providing a new therapeutic approach against asthma and indicate VDUP1/TRX maybe a marker of oxidative stress which needs to be further studied.