Identification of Nesfatin-1 in primitive vertebrate lampreys and its roles in inflammatory responses and ferroptosis.

Nesfatin-1 is an 82-amino acid polypeptide derived from the precursor protein nucleobindin 2 (NUCB2), which is a conserved multifunctional peptide in vertebrates that plays a key role in metabolic regulation, inflammatory response and ferroptosis. Although Nesfatin-1 has been characterized in various vertebrates, from mammals to teleosts, its structural and functional characteristics in primitive vertebrates remain unclear. In this study, Nesfatin-1 orthologs from the most primitive jawless vertebrate lamprey (Lethenteron camtschaticum) were cloned and identified, designated as Lc-Nesfatin-1. Bioinformatic analysis revealed that Nesfatin-1 of lamprey is relatively conserved in both sequence similarity and three-dimensional (3D) structure compared to that of higher vertebrates. Lc-Nesfatin-1 was significantly upregulated under lipopolysaccharide (LPS) stimulation, which also markedly induced the expression of pro-inflammatory cytokines, the key signaling molecule NF-κB, and anti-inflammatory cytokines. Notably, Flow cytometry analysis showed that Lc-Nesfatin-1 did not significantly inhibit LPS-induced intracellular ROS production. Furthermore, Nesfatin-1 serves as an effective negative regulator that significantly inhibits ferroptosis. These results reveal that Lc-Nesfatin-1 plays a critical role in modulating both LPS-induced inflammatory responses and ferroptosis. This study has successfully elucidated the characteristics and functions of Nesfatin-1 in primitive vertebrates and provided valuable insights into the investigation of inflammatory responses and ferroptosis in jawless vertebrates.