Expression of the Antimicrobial Peptide Piscidin 1 and Neuropeptides in Fish Gill and Skin: A Potential Participation in Neuro-Immune Interaction

Abstract

Antimicrobial peptides (AMPs) are found widespread in nature and possess antimicrobial and immunomodulatory activities. Due to their multifunctional properties, these peptides are a focus of growing body of interest and have been characterized in several fish species. Due to their similarities in amino-acid composition and amphipathic design, it has been suggested that neuropeptides may be directly involved in the innate immune response against pathogen intruders. In this review, we report the molecular characterization of the fish-specific AMP piscidin1, the production of an antibody raised against this peptide and the immunohistochemical identification of this peptide and enkephalins in the neuroepithelial cells (NECs) in the gill of several teleost fish species living in different habitats. In spite of the abundant literature on Piscidin1, the biological role of this peptide in fish visceral organs remains poorly explored, as well as the role of the neuropeptides in neuroimmune interaction in fish. The NECs, by their role as sensors of hypoxia changes in the external environments, in combination with their endocrine nature and secretion of immunomodulatory substances would influence various types of immune cells that contain piscidin, such as mast cells and eosinophils, both showing interaction with the nervous system. The discovery of piscidins in the gill and skin, their diversity and their role in the regulation of immune response will lead to better selection of these immunomodulatory molecules as drug targets to retain antimicrobial barrier function and for aquaculture therapy in the future.

An optimized antimicrobial peptide analog acts as an antibiotic adjuvant to reverse methicillin-resistant Staphylococcus aureus

“…Bioinformatics-guided optimization of AMP specificity Since the elucidation of the first piscidins, multiple others have been identified from teleost fish, mainly including dicentracin, chrysophsins, epinecidin, myxinidin, gaduscidins, moronecidins, and pleurocidins 21,22 . Interestingly, the amino acid sequences of piscidin family from different fish species are highly identical, which is manifested by low C-terminal sequence homology but a highly conserved N-terminus with histidine (His), phenylalanine (Phe), and isoleucine (Ile) residues 15,23 .…”

Histological and Chemical Analysis of Heavy Metals in Kidney and Gills of Boops boops: Melanomacrophages Centers and Rodlet Cells as Environmental Biomarkers

“…RCs are peculiar cells, equipped with granules containing serotonin and piscidin [ 81 ], a potent antimicrobial peptide [ 82 , 83 , 84 ]. They act via Toll-like receptor (TLR), a type of evolutionarily conserved receptor [ 40 , 85 , 86 , 87 , 88 , 89 , 90 , 91 ] activated in response to viruses, bacteria or organic or chemical stress [ 92 , 93 , 94 , 95 , 96 , 97 ].…”

Strategies to enhance tilapia immunity to improve their health in aquaculture

“…Nile tilapia β‐defensin has been shown to have an inhibitory effect on the growth of Escherichia coli and Streptococcus agalactiae 69 . The therapeutic potential of piscidins, 70 including tilapia piscidins, has recently been reviewed by Hazam and Chen 71 and Raju et al 72 …”