The effect of High-Molecular-Weight Kininogen Gene Silencing on Vascular Permeability

• 1、Cyrus Tang Zhongying Hematology Center，Soochow University，Suzhou 215123

Abstract：This study aims to construct humanized HK mice and use GalNAc-HK-siRNA liver-targeted specific gene silencing technology to reduce plasma HK and fundamentally inhibit BK production, so as to investigate the effect of targeted inhibition of HK on reducing vascular permeability in HAE mouse models.CRISPR/Cas9 technology was used to construct human Kng1 knock-inmice; then, these mice were mated with mouse Kng1 knockout mice to obtain mice with only humanized Kng1. Subsequently, GalNAc-siRNA targeting HK (HK mRNA) was administered via subcutaneous injection to detect the effect of reducing plasma HK after administration. Two different vascular leakage mouse models induced by angiotensin inhibitors and mustard oil were applied to evaluate the role of HK gene silencing in alleviating vascular permeability.Humanized Kng1 mice exhibited a normal genetic phenotype. They also had normal FXIIa and PKa enzymatic activities. A single subcutaneous injection of GalNAc-HK-siRNA at a dose of 3 mg/kg resulted in a reduction of more than 70% in plasma human HK mRNA and over 95% in plasma human HK protein. In two different disease models of bradykinin-driven vascular leakage, administration of GalNAc-HK-siRNA led to a dose-dependent decrease in vascular permeability, indicating that RNAi-mediated reduction of plasma HK downregulates the production of BK and alleviates bradykinin-induced increase in vascular permeability. These results suggest that RNAi-mediated knockdown of HK by GalNAc-HK-siRNA is a potentially effective therapeutic approach for HAE.

Keywords： Hereditary angioedema；GalNAc-siRNA；High-molecular-weight kininogen；Bradykinin Vascular permeability