Transient knockdown of the ACE-2 Receptor using the RALA Technology for COVID-19

RNAi疗法有可能改变医疗保健干预措施，在过去两年中，有两种产品被批准用于治疗危及生命的疾病。RNAi疗法旨在短暂地减少有缺陷的基因以达到治疗目的。这是一个快速增长的市场，有109种基于RNAi的治疗方法正在临床试验中（2018年7月）\[Turnbull 2020\]。然而，围绕RNAi疗法仍然存在一些问题，包括到达适当的组织，然后确保细胞内递送到目的地。最近的研究还表明，那些有潜在健康状况的人，如糖尿病、高血压或吸烟者，肺上皮中ACE-2受体的数量增加\[Leung 2020\]。研究表明，COVID-19利用ACE-2受体进入细胞，以产生更多的病毒颗粒，从而感染更多的ACE-2受体阳性细胞\[Kuba 2005\]。ACE-2受体在许多生物学功能中发挥着作用，但如果能在短时间内降低表达，就能降低病毒的传染性，并有助于扭转平衡，使其朝着健康恢复的方向发展。RNAi可以用来短暂地降低这种ACE-2受体的表达，但前提是有合适的递送系统。因此，在本次COVID-19资助呼吁中，pHion明确符合医疗保健的特定主题，开发了一种安全的RNAi递送解决方案，不会进一步加剧免疫系统，优先向肺部提供治疗，并且具有成本效益，最终使RNAi治疗得到广泛采用。这项创新围绕着一种被称为RALA的肽的使用，这种肽被设计成将RNAi浓缩成纳米颗粒（NPs），这些纳米颗粒具有穿过细胞膜、逃离核内体、将货物高效率地运送到细胞质的必要特性。在旨在减少ACE-2表达的RNAi和RALA肽之间形成的NPs不需要冷链储存，可以保存数月而不失去功能。这项为期6个月的中试研究旨在证明RALA/RNAi NPs可以在人肺细胞和体内短时间内降低ACE-2受体的表达。影响资助的扩展建立在初始项目的基础上，通过询问RALA/RNAi NPs在体内的安全性概况。这3个月的延长旨在完成一项研究，测量体内单次和多次注射RALA/RNAi NPs后的毒理学和免疫学反应。这项额外研究的结果将产生一个具有商业价值的数据包，以证明RALA技术的安全性。最初的项目和进一步的影响研究将提供证据，这对确保该治疗药物的未来投资进入I期试验至关重要。这种短效RNAi疗法对任何针对ACE-2受体的冠状病毒爆发都有潜力。

RNAi therapeutics have the potential to transform healthcare interventions as evidenced by the approval of 2 products in the last 2 years for life threatening diseases. RNAi therapy is designed to transiently reduce a defective gene for therapeutic purposes. It is a rapidly growing market with 109 RNAi based therapeutics in clinical trials (July 2018) \[Turnbull 2020\]. However, there are still issues that surround the RNAi therapeutics which include getting to the appropriate tissue and then ensuring intracellular delivery to the destination site. Recent studies have also indicated that those with underlying health conditions such as diabetes, high-blood pressure or smokers have an increased number of ACE-2 receptors in the lung epithelium \[Leung 2020\]. Studies have revealed that COVID-19 uses the ACE-2 receptor to enter cells in order to produce more viral particles that can infect more ACE-2 receptor positive cells \[Kuba 2005\]. The ACE-2 receptor plays a role for many biological functions but if expression could be lowered for a short period of time it could reduce the infectivity of the virus and help tip the balance towards healthy recovery. RNAi could be used to transiently reduce expression of this ACE-2 receptor but only if there is an appropriate delivery system. Therefore with clear alignment to the specific theme of healthcare in this COVID-19 grant call, pHion have developed a solution for RNAi delivery that is safe, does not further exacerbate the immune system, preferentially delivers the therapeutic to the lung and is cost-effective, ultimately enabling widespread adoption of the RNAi therapy. The innovation centres around the use of a peptide termed RALA that is designed to condense RNAi into nanoparticles (NPs) that have the properties necessary to cross cell membranes, escape endosomes delivering the cargo to the cytoplasm with high efficiency. The NPs formed between the RNAi which is designed to reduce ACE-2 expression and the RALA peptide do not require cold chain storage can be stored for many months without losing functionality. The proposed 6 month pilot study is designed to demonstrate that the RALA/RNAi NPs can reduce ACE-2 receptor expression in human lung cells and then in vivo for a short period of time. The extension for impact funding builds upon the initial project by interrogating the safety profile of the RALA/RNAi NPs in vivo. This 3 month extension is designed to complete a study that measures both the toxicological and immunological response following single and multiple injections of the RALA/RNAi NPs in vivo. The outputs from this additional study will result in a commercially valuable data pack that demonstrates how safe the RALA technology is. The original project and the further impact study will provide evidence which is critical to secure future investment for the development of this therapeutic towards a Phase I trial. This short-acting RNAi therapy holds potential for any coronavirus outbreak that targets the ACE-2 receptor.