核糖核酸酶1（RNase1）是脊椎动物所特有的一类核酸水解酶，在植食性哺乳动物中主要具有消化功能。我们前期研究发现植食性团头鲂的RNase1重组蛋白不仅具有消化活性而且具有较强的抗菌功能。为了进一步探究其抗菌作用机理，本项目拟从以下几个方面展开研究：1）通过研究RNase1蛋白对细菌细胞膜结构的影响及与细菌细胞质内DNA的相互作用，阐明其体外抗菌作用机理；2）建立团头鲂嗜水气单胞菌感染模型，研究RNase1蛋白对病原菌感染引起机体组织损伤的保护效应、免疫防御及肠道微生物稳态的调控；3）利用LPS诱导细胞损伤模型，探索RNase1过表达和敲除后对NF-κB磷酸化的影响及敲除tlr4和myd88后RNase1蛋白对细胞的保护效应是否受阻，揭示RNase1蛋白的抗菌功能通过TLR4-MYD88-NF-κB信号通路来调控，研究结果可为深入阐明RNase1蛋白的抗菌功能及分子机理提供新思路。

Ribonuclease 1 (RNase1) is a vertebrate-specific enzyme that mainly performs digestive activity in herbivorous mammals. Our previous study has shown that RNase1 exhibited both digestive activity and potent antimicrobial activity in an herbivorous fish, blunt snout bream (Megalobrama amblycephala). In order to explore the potential molecular mechanism of its antimicrobial activity, we plan to: 1) study the activity of RNase1 in cell wall structures and interaction with bacterial DNA to explore the antimicrobial mechanisms of RNase1 in vitro; 2) to better understand the regulatory effects of RNase1, its protective effects, immune defense and intestinal microflora will be investigated via an in vivo Aeromonas hydrophila infection model; 3) to further elucidate the potential regulatory mechanisms of RNase1 through the TLR4-MYD88-NF-κB signaling pathway, we will determine the phosphorylation of NF-κb both after over-expression and knockout of RNase1 gene, as well as conduct the test whether knockout of tlr4 and myd88 genes results in diminished protective effects of RNase1. These findings will provide new insights into the molecular mechanism of antimicrobial function of RNase1.