Characterization and expression of NADPH oxidase genes in stimulated splenic neutrophils of tilapia, Oreochromis niloticus by a mix of traditional Chinese medicine and Bacillus species (TCMBS)

Abstract

Traditional Chinese medicine and Bacillus species (TCMBS) mixture is an immunostimulant with considerable promise as an alternative in improving fish health. However, nothing is known on its effects on the expression of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase genes and production of reactive oxygen species (ROS) in the neutrophils of fish. The full lengths of tilapia phagocytic NADPH oxidase genes gp91 phox , p22 phox , p40 phox , p47 phox , and p67 phox were cloned and their expression profiles after TCMBS stimulus investigated. The cDNAs of tilapia gp91 phox , p22 phox , p40 phox , p47 phox , and p67 phox contained open reading frames of 1698 bp, 561 bp, 1053 bp, 1584 bp, and 1470 bp respectively, encoding 561, 186, 350, 527, and 489 amino acids respectively. Comparison of the deduced amino acid sequences showed that tilapia NADPH oxidase genes shared 58%-91% and 21%-67% identity with those of other teleost and mammals respectively. Besides, tilapia NADPH oxidase genes contain conserved domains and motifs required for ROS generation. Phylogenetic analysis suggested tilapia NADPH oxidase genes were close to those of Fundulus heteroclitus. After 2 weeks of TCMBS application showed significant upregulation in expression of NADPH oxidase genes, antioxidant genes (i.e., superoxide dismutase, catalase, and glutathione-disulphide reductase), and an increase in the production of ROS compared to the control in splenic neutrophils of tilapia. Collectively, our study provides evidence of the structure of tilapia NADPH oxidase genes and demonstrate that TCMBS application could modulate their activity in neutrophils to improve immunity in tilapia. K E Y W O R D Santioxidant genes, NADPH oxidase genes, reactive oxygen species, tilapia

Superoxide Dismutase Multigene Family from a Primitive Chondrostean Sturgeon, Acipenser baerii: Molecular Characterization, Evolution, and Antioxidant Defense during Development and Pathogen Infection

“…The lack of splenic upregulation in this study is broadly similar to findings from A. hydrophila -challenged yellow catfish, Pelteobagrus fulvidraco [ 112 ], and with the suppressed expression of immune/stress-responsive genes in the carp Cyprinus carpio during A. hydrophila challenge [ 113 ]. However, our findings are in contrast to other previous results from tilapia, Oreochromis niloticus [ 114 ]; yellow drum, N. albiflora [ 115 ]; and Korean spotted barbel, H. mylodon [ 116 ], which all suggest that the splenic upregulation of SOD is involved in antioxidant defense during bacterial infection. Because we were able to observe the significant induction of several marker genes involved in inflammation, antimicrobial defense, and/or iron sequestration (such as interleukin-1β, hepcidin, and transferrin) in the spleens of challenged individuals (data not shown), it may be assumed that the combating of infection-driven oxidative stress might not rely so much on the induction of AbSOD transcription in the spleens of A. baerii fingerlings.…”

Immunonutrition: facilitating mucosal immune response in teleost intestine with amino acids through oxidant-antioxidant balance

“…Organisms lacking this complex can suffer from chronic infections, leading to hyper-inflammation that can be fatal (86, 88). The NADPH oxidase complex consists of several subunits, including p22phox, gp91phox, p47phox, p67phox, and Rac (89,90). The subunit gp91phox is first stimulated during the complex's activation, and electrons are transferred from NADPH to O 2 within the cytosol of the cell, resulting in the production of ROS, such as superoxide anion (O 2 -) with the enzyme SOD (89,90).…”

“…The NADPH oxidase complex consists of several subunits, including p22phox, gp91phox, p47phox, p67phox, and Rac (89,90). The subunit gp91phox is first stimulated during the complex's activation, and electrons are transferred from NADPH to O 2 within the cytosol of the cell, resulting in the production of ROS, such as superoxide anion (O 2 -) with the enzyme SOD (89,90). Superoxide anion is converted to hydrogen peroxide with catalase (CAT) and can be further converted to water with peroxidase (89,90).…”

Fermented tea residue improved growth performance, liver antioxidant capacity, intestinal morphology and resistance to Aeromonas hydrophila infection in juvenile largemouth bass (Micropterus salmoides)

“…After soaking goldfish infected with A. hydrophila for a certain period of days with 1% compound herbal water, the damaged primary gill flaps, liver, heart and muscle tissue structure of goldfish are restored (Ramasamy et al, 2010). Immunostimulant (mixture of Chinese herbs and Bacillus), could significantly upregulate the expression of NADPH oxidase genes and antioxidant genes in tilapia spleen neutrophils, thus improving the immunity of tilapia (Abarike et al, 2019).…”