Shock-Trauma Research Laboratories in the Division of Surgical Research and Department of Surgery, Rhode Island Hospital and Brown University, School of Medicine, Providence, RI, USA.
Crit Care Med. 2010 Apr;38(4):1179-86. doi: 10.1097/CCM.0b013e3181d4563f.
Indirect acute lung injury is associated with high morbidity and mortality. However, the underlying pathophysiology is only marginally understood, and so far no pathophysiologic-based remedy exists. We hypothesized that apoptosis of lung epithelial cells is a pathophysiological relevant process in the development of indirect acute lung injury and that it should be accessible to a siRNA-based therapeutic intervention in vivo.
Prospective, randomized, controlled animal study.
Basic science laboratory of a university affiliated level one trauma center.
Male C3H/HeN mice, 8 wks old, n = 121.
First, siRNA sequences to knock-down caspase-3 expression at a RNA and protein level were evaluated in vitro. Then, C3H/HeN mice were subjected to hemorrhagic shock, after which they received either a caspase-3 siRNA or a control/nonsense siRNA. Subsequently, they were then subjected to polymicrobial sepsis (induced by cecal ligation and puncture).
Twelve and 24 hrs after sepsis, increased lung epithelial apoptosis was observed, as evidenced by active caspase-3 Western blotting, caspase-3, TUNEL-, and M-30 immunohistochemistry. Hallmarks of acute lung injury, such as increased concentrations of pulmonary cytokines/chemokines, lung protein leakage, myeloperoxidase activity, and altered lung histology, were evident in response to these insults. The single intratracheal instillation of caspase-3 siRNA not only attenuated lung apoptosis and inflammation but also ameliorated the development of acute lung injury in treated mice. Most interestingly, this experimental therapeutic approach markedly improved 10-day survival of hemorrhaged septic mice.
Apoptosis of lung epithelial cells is a relevant pathomechanism in the development of hemorrhage-induced indirect septic acute lung injury, and caspase-3 appears to be a valuable therapeutic target accessible by siRNA treatment in vivo.
间接性急性肺损伤与高发病率和死亡率相关。然而，其潜在的病理生理学机制仅略知一二，目前还没有基于病理生理学的治疗方法。我们假设肺上皮细胞凋亡是间接性急性肺损伤发展过程中的一个相关病理生理过程，并且它应该可以通过基于 siRNA 的治疗干预来实现。
前瞻性、随机、对照动物研究。
大学附属一级创伤中心的基础科学实验室。
雄性 C3H/HeN 小鼠，8 周龄，n = 121。
首先，评估了体外敲低 caspase-3 表达的 siRNA 序列在 RNA 和蛋白质水平上的作用。然后，将 C3H/HeN 小鼠置于失血性休克后，给予 caspase-3 siRNA 或对照/无意义 siRNA。随后，它们被施以多微生物脓毒症（通过盲肠结扎和穿刺诱导）。
在脓毒症后 12 和 24 小时，观察到肺上皮细胞凋亡增加，这一点通过活性 caspase-3 Western 印迹、caspase-3、TUNEL-和 M-30 免疫组织化学得到证实。急性肺损伤的特征，如肺细胞因子/趋化因子浓度增加、肺蛋白渗漏、髓过氧化物酶活性改变和肺组织学改变，都对这些刺激作出了反应。单次气管内滴注 caspase-3 siRNA 不仅减轻了肺细胞凋亡和炎症，还改善了治疗小鼠的急性肺损伤发展。最有趣的是，这种实验性治疗方法显著提高了失血性脓毒症小鼠的 10 天存活率。
肺上皮细胞凋亡是失血性间接性脓毒症急性肺损伤发展过程中的一个相关病理机制，caspase-3 似乎是一种有价值的治疗靶点，可通过体内 siRNA 治疗来实现。
