Mindin promotes the production of reactive oxygen species to regulate intestinal microbiota in kuruma shrimp Marsupenaeus japonicus

• Mindin plays an antibacterial role in the intestine of marsupenaeus japonicus . • Mindin promotes the production of reactive oxygen species. • Mindin regulates the transcription of dual oxidase 2. The Mindin/Spondin family, as host extracellular matrix components, comprises key immune-related molecules in both mammals and Drosophila . While the detailed mechanisms of Mindin's function and its role in initiating an effective immune response have been elucidated in model animals, its immune regulatory function in invertebrates remains largely unknown. In the present study, we identified and characterized a Mindin homolog from kuruma shrimp ( Marsupenaeus japonicus ), which was significantly up-regulated upon Vibrio anguillarum infection. Our findings revealed that Mindin plays a crucial protective role in the antibacterial response by regulating dual oxidase 2 (Duox2) expression. Mechanistically, Mindin recognizes V. anguillarum through its Tsp domain and simultaneously interacts with cell membrane integrin via its SpN domain. This dual interaction triggers the phosphorylation of extracellular regulated kinase (Erk), leading to the activation and phosphorylation of transcription factor Atf2. The phosphorylated Atf2 translocates to the nucleus where it induces the expression of Duox2, resulting in the production of reactive oxygen species (ROS) that effectively inhibit bacterial growth. By establishing the Mindin/Integrin/Erk/Atf2/Duox2 signaling axis, this study unveils a novel antibacterial mechanism in shrimp and provides new insights into the functional role of Mindin in invertebrate immunity.