摘要目的 观察信号转导子与转录活化子1(STAT1)反义寡核苷酸雾化吸入对博来霉素致肺纤维化大鼠肺组织中Ⅰ、Ⅲ型胶原,纤溶酶原激活物抑制剂-1(PAI-1),转化生长因子-β_1(TGF-β_1)和羟脯氨酸表达的影响.方法 将45只Wistar大鼠按随机数字表法分为生理盐水组、博来霉素组和寡核苷酸组,每组15只,分别在气管内灌注并雾化吸入生理盐水、博来霉素、STAT1反义寡核苷酸.分别于雾化后第7天、第14天和第28天每组各处死5只大鼠.肺组织HE染色和Masson染色观察肺泡炎和肺纤维化改变,免疫组织化学SP法测定肺组织中TGF-β_1、PAI-1表达,逆转录PCR测定肺组织中Ⅰ、Ⅲ型胶原mRNA表达,肺组织匀浆测定羟脯氨酸含量.样本均数间比较采用单因素方差分析和q检验.结果 寡核苷酸组大鼠各时间点的肺泡炎和肺纤维化程度均较博来霉素组减轻.博来霉素组和寡核苷酸组大鼠肺组织中TGF-β、PAI-1表达水平均明显高于生理盐水组,博来霉素组和寡核苷酸组大鼠雾化后第7天TGF-β、PAI-1的积分吸光度值分别为182±12和169±12、128±11和113±13,明显高于生理盐水组的21±6和27±9,第28天时(68±7和87±7、54±8和57±8)仍高于生理盐水组(22±7和26±7);雾化后第7天、第14天和第28天,寡核苷酸组大鼠Ⅰ、Ⅲ型胶原mRNA表达水平分别为1.36±0.10、1.19±0.28、1.22±0.24和1.20±0.09、0.62±0.09、0.76±0.12,明显低于博来霉素组(3.29±0.28、2.04±0.25、1.91±0.30和1.63±0.15、1.58±0.13、1.12±0.09),寡核苷酸组大鼠肺组织中羟脯氨酸含量(mg/g)分别为3.02±0.13、3.24±0.31和3.60±0.16,明显低于博来霉素组的3.76±0.10、3.92±0.30和4.62±0.28.结论 STAT1反义寡核苷酸雾化吸入能减轻博来霉素致肺纤维化大鼠肺泡炎和肺纤维化,其机制可能与抑制TGF-β_1、PAI-1的表达,Ⅰ、Ⅲ型胶原mRNA表达减少,羟脯氨酸含量降低有关.

abstractsObjective To investigate the effects of aerosolized signal transducer and activator of transcription 1 (STAT1) antisense oligonucleotides(ASON) on the expressions of TGF-β_1, PAI-1, collagen Type Ⅰ and Ⅲ and hydroxyproline in lung tissue of pulmonary fibrosis induced by bleomycin (BLM) in rats. Methods Forty-five adult female Wistar rats were randomly divided into 3 groups: normal saline(NS) group, BLM group and ASON group. The BLM group and the ASON group were intratracheally instilled with BLM while the NS group was instilled with NS. The NS group and the BLM group were aerosolized with NS while the ASON group was aerosolized with STAT1 ASON on day 0,2, 4, and 6. Then the rats were killed on day 7, 14, and 28. TGF-1 and PAI-1 protein in the tissue of left lung were assessed by immunohistochemistry. The mRNA levels of collagen type Ⅰ and Ⅲ of fight lung were measured by reverse transcriptase-polymerase chain reaction (RT-PCR). The content of hydroxyproline was also examined. Results Compared with the BLM group, the scores of alveolitis and fibrosis in the ASON group were remarkably reduced. Both TGF-β_1 and PAI-1 protein in lung tissue in the BLM group and the ASON group were significantly higher as compared with the NS group. Compared with the BLM group, the mRNA levels of collagen type Ⅰ and Ⅲ in the ASON group were decreased. At day 7, 14 and 28, the mRNA levels of collagen type Ⅰ and Ⅲ in the ASON group were 1.36±0.10, 1.19±0.28, 1.22±0.24 and 1.20±0.09, 0.62±0.09, 0.76±0.12,respectively,both increased significantly as compared to those in the BLM group (3.29±0.28, 2.04±0.25, 1.91±0.30 and 1.63±0.15, 1.58±0.13, 1.12±0.09,respectively). The content of hydroxyproline (mg/g) in lung tissue in the ASON group at day 7, 14 and 28 was 3.02±0.13, 3.24±0.31, and 3.60±0.16, respectively, which were lower than those of the BLM group (3.76±0.10, 3.92±0.30, and 4.62±0.28, respectively). Conclusions Aerosolized STAT1 ASON inhibited alveolitis and fibrosis in BLM-induced pulmonary fibrosis, via inhibition of the expression of PAI-1 and TGF-β1, decrease of the mRNA levels of collagen Type Ⅰ and Ⅲ, and the reduction of hydroxyproline production.