Targeted mRNA therapies treating ARDS - Project Summary/Abstract: This proposal describes a research plan for Zhengjie Zhou, Ph.D., for the R00 portion of the NIH mentored career award (K99/R00). The PI is completing training in an NIH K99 fellowship (K99HL166870) and is trained in vascular biology, lung biology, molecular biology, and bioengineering. This proposal tests the overall hypothesis of formulating novel lung-targeting nanoparticles to deliver therapeutic mRNA in a cell-specific manner for the treatment of acute respiratory distress syndrome (ARDS), which is the major cause of death for severe influenza and SARS-CoV-2 infection. Currently, efficient medicines are still lacking for ARDS therapy. ARDS is characterized by the dysfunction of endothelial cells (ECs), epithelial cells, and the following uncontrolled cytokine storm. Based on our recent research about a vascular cell adhesion molecule-1 (VCAM1) targeting nanotherapeutic study, I rationally designed and optimized a targeting lipid nanoparticle (LNP) that enables robust mRNA delivery in vivo in a cell-specific manner. Leveraging this mRNA delivery platform, We propose to (i) promote endothelium health by endothelial cell-specific delivery of KLF2 mRNA to restore KLF2, a transcription factor, that plays a key role in facilitating endothelial health and vasculature homeostasis. KLF2 was demonstrated significantly reduced in mice lungs induced by LPS, influenza H1N1, SARS-CoV-2, and COVID-19 patients lungs; (ii) activate epithelial cells innate immune pathway by epithelium specific delivery of 2’-5’-oligoadenylate synthetase 1 (OAS1) mRNA to augment epithelium interferon (IFN) response through OAS/RNase L pathway to defense respiratory viral infection. Our data demonstrated that KLF2 mRNA/VCAM1-targeting LNP targeted the inflamed mice lungs endothelium and significantly reduced the ARDS induced by H1N1. Our preliminary data demonstrated that the OAS1 mRNA/epithelium-targeting LNP targeted the mice inflamed lung epithelium and significantly reduced the H1N1 replication and lung ARDS. Aim 1 will comprehensively evaluate the therapeutic potency of VCAM1-targeting LNP to restore endothelial KLF2 and lessen ARDS in a clinically relevant rat ARDS model induced by high-tidal ventilation (HTV). Aim 2 will determine how epithelium-targeted delivery of OAS1 activates the innate immune response and exerts antiviral effects in mice by OAS1 mRNA/epithelium-targeting LNP, and will determine its therapeutic effect to treat respiratory virus-induced ARDS. Successful completion of these projects will provide a promising mRNA therapeutic treating lung disease and provide an “effective responder” in viral pandemics, regardless of virus evolution and mutation. This mRNA delivery platform is adaptable and potentially beneficial for various cardiovascular diseases.