Cloning, tissue distribution, and stimulus-responsive mRNA expression of CD10 (neprilysin) in Lethenteron reissneri

This study presents the first systematic characterization of the molecular evolution and immune-related expression of the Lr-CD10 in the Lethenteron reissneri. Screening and bioinformatic analysis of the L. reissneri genome database confirmed that Lr-CD10 retains the core functional domains characteristic of the vertebrate CD10 gene family, including the zinc-binding motif HEXXH and catalytic active site. This indicates that the metallopeptidase activity of CD10 was established within a conserved functional framework early in vertebrate evolution. To investigate the potential biological role of Lr-CD10, we performed targeted gene knockdown in L. reissneri and conducted comparative transcriptome analysis, generating comprehensive gene expression profiles. The results suggest that CD10-mediated metallopeptidase activity may play dual roles: inflammation regulation and extracellular matrix remodeling. Our findings reveal an immune regulatory network associated with CD10 in an early vertebrate and provide transcriptomic evidence supporting its multifaceted functional evolution. Furthermore, cross-species comparison indicates that certain core immune regulatory modules are conserved across evolution, although their specific functional roles may diverge. This work provides a novel theoretical framework for investigating the evolutionary-developmental principles of the immune system and proposes an ancient origin for tumor microenvironment regulation, offering testable hypotheses for future functional studies.