The expression signatures of neuronal nitric oxide synthase (NOS1) in turbot (Scophthalmus maximus L.) mucosal surfaces against bacterial challenge

Fish Shellfish Immunol. 2016 Dec:59:406-413. doi: 10.1016/j.fsi.2016.11.013. Epub 2016 Nov 5.

Abstract

The mucosal surfaces constitute the first immune barrier of host defense and also serve as the dynamic interfaces that simultaneously mediate a diverse array of critical physiological processes. It has been long hypothesized that observed difference of disease resistance among different fish strains and species are strongly correlated to the activities of the immune actors in mucosal surfaces. Particularly, neuronal NOS (nNOS or NOS1) is a constitutively expressed gene that catalyzes the oxidation of l-arginine and water to nitric oxide (NO), which is known as a potent host defence effector in immune system with antimicrobial activity. Moreover, NOS1 was detected to be expressed in fish mucosal surfaces, but its activities in mucosal immune responses were always overlooked. In this regard, we identified the NOS1 of turbot and characterized its expression patterns in mucosal tissues following Vibrio anguillarum and Streptococcus iniae challenge. The results showed that the NOS1 gene had a 4389 bp open reading frame (ORF) that encoded 1462 amino acids. Phylogenetic analysis showed the turbot NOS1 had the strongest relationship to Larimichthys crocea. And the syntenic analysis revealed the similar neighboring genes associated with turbot NOS1, compared with other teleost and mammals. In addition, NOS1 was widely expressed in all examined tissues with the highest expression level in brain, followed by intestine and gill. Finally, the NOS1 showed a general trend of up-regulation in mucosal tissues following both bacterial challenge, with the highest up-regulation in intestine. The significant quick induction of NOS1 in mucosal surfaces against infection indicated its key roles to prevent pathogen attachment and entry in mucosal immunity. More functional studies are needed to conduct in teleost to better understand the roles of NOS1 in maintaining the integrity of the mucosal barriers against infection.

Keywords: Mucosal immunity; Neuronal nitric oxide synthase (NOS1); Streptococcus iniae; Turbot; Vibrio anguillarum.

MeSH terms

  • Animals
  • Fish Diseases / genetics*
  • Fish Diseases / immunology
  • Fish Diseases / microbiology
  • Fish Proteins / chemistry
  • Fish Proteins / genetics*
  • Fish Proteins / metabolism
  • Flatfishes*
  • Gene Expression Regulation*
  • Immunity, Innate
  • Mucous Membrane / immunology
  • Nitric Oxide Synthase Type I / chemistry
  • Nitric Oxide Synthase Type I / genetics*
  • Nitric Oxide Synthase Type I / metabolism
  • Organ Specificity
  • Phylogeny
  • Random Allocation
  • Sequence Alignment / veterinary
  • Sequence Analysis, DNA / veterinary
  • Streptococcal Infections / genetics
  • Streptococcal Infections / immunology
  • Streptococcal Infections / microbiology
  • Streptococcal Infections / veterinary*
  • Streptococcus iniae / physiology
  • Vibrio / physiology
  • Vibrio Infections / genetics
  • Vibrio Infections / immunology
  • Vibrio Infections / microbiology
  • Vibrio Infections / veterinary*

Substances

  • Fish Proteins
  • Nitric Oxide Synthase Type I