Infection with avian influenza A H5N1 virus results in acute lung injury (ALI) and has a high mortality rate (52.79%) because there are limited therapies available for treatment. Drug repositioning is an economical approach to drug discovery. We developed a method for drug repositioning based on high-throughput RNA sequencing and identified several drugs as potential treatments for avian influenza A H5N1 virus. Using high-throughput RNA sequencing, we identified a total of 1,233 genes differentially expressed in A549 cells upon H5N1 virus infection. Among these candidate genes, 79 drug targets (corresponding to 59 approved drugs) overlapped with the DrugBank target database. Twenty-two of the 41 commercially available small-molecule drugs reduced H5N1-mediated cell death in cultured A549 cells, and fifteen drugs that protected A549 cells when administered both pre- and post-infection were tested in an H5N1-infection mouse model. The results showed significant alleviation of acute lung injury by amitriptyline HCl (an antidepressant drug), flavin adenine dinucleotide (FAD; an ophthalmic agent for vitamin B2 deficiency), azacitidine (an anti-neoplastic drug) and calcitriol (an active form of vitamin D). All four agents significantly reduced the infiltrating cell count and decreased the lung injury score in H5N1 virus-infected mice based on lung histopathology, significantly improved mouse lung edema by reducing the wet-to-dry weight ratio of lung tissue and significantly improved the survival of H5N1 virus-infected mice. This study not only identifies novel potential therapies for influenza H5N1 virus-induced lung injury but also provides a highly effective and economical screening method for repurposing drugs that may be generalizable for the prevention and therapy of other diseases.

禽流感H5N1禽流感病毒感染会导致急性肺损伤（ALI），并且由于可用于治疗的疗法有限，因此死亡率很高（52.79％）。药物重新定位是发现药物的一种经济方法。我们开发了一种基于高通量RNA测序的药物重新定位方法，并确定了几种药物可作为治疗A型H5N1禽流感病毒的潜在药物。使用高通量RNA测序，我们确定了H5N1病毒感染后在A549细胞中差异表达的总共1,233个基因。在这些候选基因中，有79个药物靶标（对应于59种已批准的药物）与DrugBank目标数据库重叠。在41种市售小分子药物中，有22种减少了培养的A549细胞中H5N1介导的细胞死亡，在H5N1感染小鼠模型中测试了在感染前和感染后同时给予A549细胞保护的15种药物。结果表明，阿米替林HCl（抗抑郁药），黄素腺嘌呤二核苷酸（FAD；维生素B2缺乏症的眼药），阿扎胞苷（抗肿瘤药）和骨化三醇（维生素D的活性形式）可显着减轻急性肺损伤）。基于肺组织病理学，所有四种药物均显着降低了感染H5N1病毒的小鼠的浸润细胞数并降低了肺损伤评分，通过降低肺组织的干重比显着改善了小鼠肺水肿，并显着提高了肝细胞的存活率。 H5N1病毒感染的小鼠。