A multimodal delivery and treatment approach for Acute Lung Injury

急性肺损伤(ALI)和急性呼吸窘迫综合征(ARDS)是常见的、破坏性的临床疾病 影响大量(美国每年200,000例)和大约30%的综合症 在目前的护理标准下，儿童死亡率很低。我们已经开发出一种高度有效的治疗这种疾病的方法 利用普遍存在的Na+，K+-β酶1亚单位过度表达的小鼠和猪模型 增加先前受伤肺的肺泡液清除量。我们的实验表明，这种治疗方法不会 不仅可以改善水肿消退(以及肺功能和存活率)，还可以改善肺泡上皮细胞。 内皮屏障通过上调紧密连接复合体发挥作用。高效和安全的基因传递是 利用电穿孔技术，将简短的同步方波电脉冲应用于 抽吸裸露DNA后的胸部。该手术不会造成创伤，不会发炎，也不会造成肺部 在50公斤健康猪或败血症猪中，能量消耗低于0.1J/kg。我们有 在90多名健康患者和60名脓毒症患者中，在最佳场强下经胸电穿孔无死亡病例 患有急性呼吸窘迫综合征的猪。我们发现，α是丝氨酸/苏氨酸蛋白激酶，也是丝氨酸/苏氨酸蛋白激酶下游的效应因子。 细胞骨架重组的CDC42是由β-1过表达激活的，对于增加的 β1引起的紧密连接蛋白的活性/丰度。我们已经证明这两种蛋白相互作用， β1亚单位激活MERCKα，即抑制或基因沉默肺泡I型上皮中的MERCKα 细胞取消β-1过表达增加紧密连接丰度和活性的能力 MERCKα的过表达改善了培养的肺泡I型上皮细胞的屏障特性。 虽然β1的过度表达增加了水肿清除和屏障功能，但我们不知道哪种活动起作用 在其治疗能力中发挥着主导作用。此外，对Mr CKα的识别可能会为 ALI/ARDS的治疗。我们还发现，已报道的miRNA miR-181a是 急性呼吸窘迫综合征患者血清中Na+，K+-ATPaseβ1的3‘UTRs显著升高 亚基(但不包括任何其他Na+，K+-ATPase亚基)和mRCKα。通过转导An基因抑制该miRNA 反抗剂增加细胞中β-1亚单位和mRCK-α的表达。我们的研究还将测试 调节miR-181a可以增加Na+，K+-ATPaseβ1亚单位和mRCKα以促进肺的分辨率 致伤小鼠ALI/ARDS模型。我们将使用新型的环状两亲性多肽纳米颗粒来传递RNA 我们已经成功地将其用于细胞和小鼠的肺中。目标是(1)确定是否有改进 肺泡液清除是Na+，K+-ATPase基因转移治疗的主要机制 (2)检测MRCKα基因转移诱导屏障功能是否具有保护作用 和/或对小鼠ALI/ARDS的治疗；以及(3)确定仅miR-181a抑制剂的基因转移 可治疗ALI/ARDS或进一步增强Na+，K+-ATPase基因转移介导的治疗作用。

Acute lung injury (ALI) and Acute Respiratory Distress Syndrome (ARDS) are common, devastating clinical syndromes that affect large numbers of (200,000 cases in the US per year) and have approximately 30% mortality with the current standard of care. We have developed a highly effective treatment for this disease in mouse and pig models that uses the ubiquitous overexperssion of the β1 subunit of the Na+,K+-ATPase to increase alveolar fluid clearance from the previously injured lung. Our experiments show that this treatment not only improves edema resolution (and lung function and survival), but also improves alveolar epithelial/ endothelial barrier function by upregulating tight junction complexes. Highly efficient and safe gene delivery is carried out using electroporation, the application of brief synchronized square wave electric pulses across the chest following naked DNA delivery by aspiration. The procedure causes no trauma, no inflammation, no lung injury, no cardiac dysfunction, and uses less than 0.1 J/kg of energy in 50 kg healthy or septic pigs. We have had no deaths from transthoracic electroporation at optimal field strengths in over 90 healthy and 60 septic pigs with ARDS. We have found that MRCKα, a serine/threonine-protein kinase and a downstream effector of Cdc42 for cytoskeletal reorganization, is activated by β1 overexpression and is needed for the increased activity/abundance of tight junction proteins caused by β1. We have shown that these two proteins interact, that the β1 subunit activates MRCKα, that inhibition or genetic silencing of MRCKα in alveolar type I epithelial cells abrogates the ability of β1 overexpression to increase tight junction abundance and activity in cultured cells, and that overexpression of MRCKα improves barrier properties in cultured alveolar type I epithelial cells. While β1 overexpression increases edema clearance and barrier function, we do not know which activity plays the predominant role in its treatment ability. Further, the identification of MRCKα may provide a new target for treatment of ALI/ARDS. We have also found that the miRNA miR-181a that has been reported to be significantly increased in the serum of ARDS patients, targets the 3'UTRs of both the Na+,K+-ATPase β1 subunit (but not any other Na+,K+-ATPase subunit) and MRCKα. Inhibition of this miRNA by transfection of an antagomer increases expression of both the β1 subunit and MRCKα in cells. Our studies will also test whether modulation of miR-181a can increase both the Na+,K+-ATPase β1 subunit and MRCKα to aid resolution of lung injury in mouse ALI/ARDS models. We will use novel cyclic amphipathic peptide nanoparticles for RNA delivery that we have used successfully in cells and the mouse lung. The aims are to (1) determine whether improved alveolar fluid clearance is the primary mechanism by which gene transfer of the Na+,K+-ATPase treats ALI/ARDS; (2) test whether induction of barrier function by gene transfer of MRCKα can mediate protection and/or treatment of ALI/ARDS in mice; and (3) determine whether gene transfer of an miR-181a inhibitor alone can treat ALI/ARDS or further enhance Na+,K+-ATPase gene transfer-mediated treatment in mice.