Targeted delivery of novel miRNA-based therapeutics for pneumonia-induced acute lung injury

摘要 我们建议开发一种基于miRNA的新疗法来治疗细菌性肺炎所致的急性肺损伤。 模特。细菌性肺炎是导致儿童和老年人严重和致命感染的主要原因。 全世界。即使使用抗生素干预，许多患者仍迅速发展为急性呼吸窘迫。 需要住院、重症监护和机械通气的综合征(ARDS)。急性呼吸窘迫综合征的死亡率 患者人数很高，许多幸存者仍面临着从各种长期并发症中恢复的漫长道路。 肺功能障碍。ARDS的康复关键依赖于受损的呼吸道上皮细胞的再生 细胞，不能修复上皮损伤会损害肺功能，使呼吸道容易复发 感染和呼吸道炎症。目前还没有FDA批准的治疗方法来刺激血管再生 肺组织修复肺损伤，这将为肺炎/ARDS患者提供极大的好处。在我们的 用肺炎链球菌(Sp)引起的小鼠肺炎模型的初步研究 观察到的急性肺损伤，呼吸道上皮细胞(AECs)大量破坏和广泛损害 至实质的远端呼吸道，类似于人类ARDS患者的病理描述。我们 发现Sp感染诱导特定miRNA家族在肺中的肺表达，该家族扮演着 胚胎发育过程中呼吸道上皮细胞发生的关键作用。为了测试该miRNA在 为了修复肺损伤，我们用脂质体治疗Sp感染的小鼠，脂质体载“miRNA-imimic”，一种双重- 在体内模拟和增强内源性miRNA功能的链状RNA分子。我们发现 给感染Sp的小鼠注射模拟miRNA促进了呼吸道上皮再生，导致 改善肺功能，增强宿主恢复和存活率。将这些发现转化为临床 应用，我们建议进一步改进这项技术，将miRNA-Mimic靶向递送到炎症 肺部，以提高疗效，最大限度地减少非靶向影响，并减少潜在的药物毒性。为此，我们将 研制以miRNA为载体的肺泡靶向脂质体(ATLS)，并评价其在肺内的蓄积和 静脉给药后与非靶向给药的疗效比较。我们还将 评价pharmacokinetics/bio-distribution/pharmacodynamics在感染Sp的小鼠和EX中的安全性 活体人肺。这项第一期工程的成果将为未来的研究奠定基础，以开发出第一个- 治疗肺炎/急性呼吸窘迫综合征的再生医学类药物。

SUMMARY We propose to develop a novel miRNA-based therapeutic to treat acute lung injury in a bacterial pneumonia model. Bacterial pneumonia is a leading cause of serious and lethal infections in children and the elderly worldwide. Even with antibiotic intervention, many patients still rapidly progress to acute respiratory distress syndrome (ARDS) requiring hospitalization, intensive care, and mechanical ventilation. Mortality rate in ARDS patients is high, with many survivors still facing a long road to recovery from various long-term complications of lung dysfunction. Recovery from ARDS is critically dependent on regeneration of the damaged airway epithelial cells, and failure to repair epithelial damage impairs lung function and leaves airways vulnerable to recurrent infection and airway inflammation. There are currently no FDA approved therapies to stimulate regrowth of lung tissue to repair lung injury, which would provide great benefits to pneumonia/ARDS patients. In our preliminary studies using a mouse model of pneumonia caused by Streptococcus pneumoniae (Sp), we observed acute lung injury with substantial destruction of airway epithelial cells (AECs) and extensive damage to the distal airway of the parenchyma, similar to pathology described in human patients with ARDS. We discovered that Sp-infection induces lung expression in the lung of a specific family of miRNA that plays a critical role in the generation of respiratory epithelia during embryogenesis. To test the role of this miRNA in repairing lung injury, we treated Sp-infected mice with liposomes loaded with “miRNA-mimic”, a double- stranded RNA molecule intended to mimic and augment the function of endogenous miRNA in vivo. We found that administration of miRNA-mimic to Sp-infected mice promoted airway epithelial regeneration, resulting in improved lung function, enhanced host recovery and survival. To translate these findings into clinical application, we propose to further improve this technology with targeted delivery of miRNA-mimic to inflamed lungs, to increase efficacy, minimize off-target effects, and reduce potential drug toxicity. To this end, we will develop alveolar-targeted liposomes (ATLs) loaded with miRNA-mimic and assess lung accumulation and therapeutic efficacy after intravenous administration compared to the non-targeted counterparts. We will also evaluate pharmacokinetics/bio-distribution/pharmacodynamics and safety profiles in Sp-infected mice and ex vivo human lung. The results of this phase I STTR project will set the stage for future studies to develop a first- in-class drug of regenerative medicine for treating pneumonia/ARDS.