Molecular characterization and expression profiling of tandem-repeat galectin-8 from red-spotted grouper (Epinephelus akaara): Potential antibacterial, antiviral, and wound healing activities. Issue 121 (February 2022)

• Record Type: Journal Article
• Authors: Ganeshalingam, Subothini; Sandamalika, W.M. Gayashani; Lim, Chaehyeon; Yang, Hyerim; Liyanage, D.S.; Nadarajapillai, Kishanthini; Jeong, Taehyug; Lee, Jehee
• Is Part Of: Fish & shellfish immunology. Issue 121(2022)
• Page Start: 86
• Page End: 98
• Publication Date: 2022-02
• Subjects: Galectin-8 -- Red-spotted grouper -- Bacterial agglutination -- Wound healing; Fishes -- Immunology -- Periodicals; Shellfish -- Immunology -- Periodicals; Poissons -- Immunologie -- Périodiques; Crustacés -- Immunologie -- Périodiques; 571.9617
• DOI: 10.1016/j.fsi.2021.12.056
• Languages: English
• ISSNs: 1050-4648

Abstract

Abstract: Galectin-8 is a typical β-galactoside binding lectin, which primarily functions as a pattern recognition receptor and/or danger receptor that is engaged in pathogen recognition by the host innate immune system. Although several fish galectins have been identified, the role of galectin-8 in teleost immunity is still not fully understood. In this study, molecular, transcriptional, and immune-related functions of galectin-8 ( EaGal8 ) from red-spotted grouper ( Epinephelus akaara ) were analyzed. The open reading frame of EaGal8 comprised 960 bp encoding 319 amino acids of a ∼35 kDa protein, composed of the N- and C-terminal carbohydrate recognition domains joined by a short hinge peptide. Phylogenetic analysis revealed that EaGal8 was closely related to the Epinephelus lanceolatus galectin-8-like protein. Although EaGal8 showed ubiquitous tissue expression, the highest expression level was observed in the blood. Immunostimulants, including lipopolysaccharide, poly(I:C), and nervous necrosis virus, significantly upregulated the EaGal8 transcription level in a time-dependent manner ( p < 0.05). Furthermore, recombinant EaGal8 (rEaGal8) showed a binding affinity toward seven different carbohydrates in a concentration-dependent manner. In addition, rEaGal8 caused strong agglutination of fish red blood cells and several gram-positive and gram-negative bacteria, including Streptococcus iniae, Streptococcus parauberis, Lactococcus garvieae, Escherichia coli, Edwardsiella tarda, Vibrio alginolyticus, Vibrio parahaemolyticus, and Pseudomonas aeruginosa . For the first time in teleosts, we report the wound healing ability of galectin-8 in this study. At low concentrations, rEaGal8 showed potential wound healing responses in FHM cells, in vitro . Thus, this study reinforces the role of EaGal8 in innate immune responses against bacterial and viral infections and wound healing in red-spotted grouper. Highlights: Galectin-8 gene was identified in red-spotted grouper ( EaGal8 ). EaGal8 was highly expressed in blood, brain, and kidney tissues. EaGal8 mRNA expression level was significantly upregulated after immune challenges including LPS, poly I:C and NNV. rEaGal8 could agglutinate fish RBCs and gram (+) and gram (−) marine bacterial strains. rEaGal8 revealed wound healing activity in FHM cells.