Fish & shellfish immunology最新文献

{"title":"Effects of dietary taurine on growth, taurine metabolism and Vibrio crassostreae resistance in juvenile clam Ruditapes philippinarum","authors":"Yang Liu ,&nbsp;Kai Liao ,&nbsp;Yuxiang Zhu ,&nbsp;Yang Zhang ,&nbsp;Hailong Huang ,&nbsp;Hui Ge ,&nbsp;Jilin Xu","doi":"10.1016/j.fsi.2025.110285","DOIUrl":"10.1016/j.fsi.2025.110285","url":null,"abstract":"<div><div>Taurine serves an important role in all aquatic animals. The purpose of this experiment was to investigate the effects of exogenous taurine on growth, endogenous taurine metabolism, and <em>Vibrio crassostreae</em> resistance in juvenile clam <em>Ruditapes philippinarum</em>. Microencapsulated taurine concentrations of 0, 0.75, 1.5, 3 and 6 mg/g clam wet weight were designated as the T0, T0.75, T1.5, T3 and T6 groups. After 2 weeks of feeding, the results demonstrated that exogenous taurine did not promote the growth of clams (<em>P</em> &gt; 0.05). The taurine content of clams was increased significantly with the increase of exogenous taurine content (<em>P</em> &lt; 0.05). The gene expression of taurine transporter (<em>TauT</em>) was significantly elevated in the T3 and T6 groups compared to the T0 group (<em>P</em> &lt; 0.05). With the addition of exogenous taurine, mRNA expressions of cysteine sulfinic acid decarboxylase (<em>CSAD</em>)<em>,</em> 2-aminoethylsulfide dioxygenase (<em>ADO</em>)<em>,</em> cysteine dioxygenase (<em>CDO</em>)<em>,</em> cystathionine β-synthase (<em>CBS</em>)<em>,</em> cystathionine γ-lyase (<em>CSE</em>) and serine dehydratase (<em>SDH</em>) were suppressed (<em>P</em> &lt; 0.05). The survival rate of clams challenged with <em>Vibrio crassostreae</em> was significantly higher in the T0.75 group compared to the T0 group on the fifth day (<em>P</em> &lt; 0.05). Additionally, the activities of antioxidant enzymes and lysozyme were significantly elevated, immune-related and anti-inflammatory factor genes were upregulated, while pro-inflammatory factor genes were downregulated in the T0.75 group compared to the T0 group (<em>P</em> &lt; 0.05). Dietary taurine supplementation regulates endogenous taurine metabolism and exhibits potential anti-<em>Vibrio</em> effect in clam <em>R. philippinarum</em>.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"161 ","pages":"Article 110285"},"PeriodicalIF":4.1,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143669373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The deficiency of virulence factor AerA in Aeromonas veronii alleviates intestinal injury and microbiota disorders in largemouth bass (Micropterus salmoides)","authors":"Lu-Chuan Zhao ,&nbsp;Ze-Sheng Zhang ,&nbsp;Zhen-Zhen Yuan ,&nbsp;Hui-Min Zhang ,&nbsp;Jing-Bao Yang ,&nbsp;Qian-Rong Liang ,&nbsp;Shun-Fa Yi ,&nbsp;Meng-Meng Huang ,&nbsp;Hui Fei ,&nbsp;Shun Yang","doi":"10.1016/j.fsi.2025.110281","DOIUrl":"10.1016/j.fsi.2025.110281","url":null,"abstract":"<div><div><em>Aeromonas veronii</em> is a zoonotic pathogen that causes considerable mortality in aquaculture, with typical manifestations of intestinal injury. Aerolysin (AerA) is a pivotal virulence factor that influences <em>Aeromonas</em> pathogenicity. This study aimed to investigate the functional mechanism of AerA in <em>A. veronii</em>-induced intestinal injury in largemouth bass (<em>Micropterus salmoides</em>). The results revealed that wild-type (WT) <em>A. veronii</em> infection provoked a noteworthy augmentation of abundance of <em>A. veronii</em> in the intestine, accompanied by inflammation, partial repression of immune response, intestinal injury and high mortality. Compared to WT <em>A. veronii</em> infection, significantly reduced levels of <em>A. veronii</em> in the intestine, inflammation, intestinal injury and mortality, as well as enhanced immune response were observed in <em>AerA</em> mutant (Δ<em>AerA</em>) <em>A. veronii</em> infection. In addition, an increase in abundance of A. veroniii in the intestine, inflammation, and higher mortality were once again perceived subsequent to the use of recombinant AerA protein to compensate for <em>AerA</em> depletion. These results demonstrated that AerA deficiency reduce the increased abundance of <em>A. veronii</em> in the intestine, inflammation and intestinal injury caused by <em>A. veronii</em> infection, thereby reducing the virulence of <em>A. veronii</em>. Our findings enhance the understanding of attributes and functional role of AerA in <em>A. veronii</em> infection, and provide guidance for the development of disease control strategies.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"161 ","pages":"Article 110281"},"PeriodicalIF":4.1,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143663081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Immunoprotective role of fish mucus against the ectoparasitic flatworm Sparicotyle chrysophrii","authors":"Enrique Riera-Ferrer,&nbsp;M. Carla Piazzon,&nbsp;Raquel Del Pozo,&nbsp;Elena Gimeno Bañón,&nbsp;Oswaldo Palenzuela,&nbsp;Ariadna Sitjà-Bobadilla,&nbsp;Itziar Estensoro","doi":"10.1016/j.fsi.2025.110282","DOIUrl":"10.1016/j.fsi.2025.110282","url":null,"abstract":"<div><div>The gill ectoparasite, <em>Sparicotyle chrysophrii</em>, has a significant impact on gilthead seabream farming in the Mediterranean. Yet, it remains unclear whether gilthead seabream develops immunological memory and protection following exposure to the parasite, which causes severe anaemia by feeding on the host's blood.</div><div>This study compared recovered gilthead seabream (RE), which had overcome sparicotylosis, and naïve fish (NAI), never exposureed to the parasite. Both groups were exposed to <em>S. chrysophrii</em> eggs, and parasitic burdens, biometric and haematological parameters were monitored over 62 days post-exposure (dpe). Total and specific IgM and IgT titers were measured in plasma and gill mucus by ELISA, binding specificity of specific immunoglobulins were determined by immunohistochemistry, and immunoglobulin-expressing cells were quantified in spleens and gills of RE and NAI fish.</div><div>Infection outcome, haematological parameters and fish fitness were worse in NAI than in RE fish. Results showed a strong mucosal immune response in RE gills, with high local secretion of parasite-specific immunoglobulins, particularly IgT, which were absent in NAI and undetectable in plasma of all recipient fish. Five months after the initial exposure, RE gill mucus still had significantly higher specific IgM and IgT titers than NAI. However, after the secondary exposure, these titres gradually decreased in RE, eventually becoming significantly lower than in NAI by the end of the trial. Immunohistochemistry confirmed the binding specificity of anti-<em>S. chrysophrii</em> IgT in RE gill mucus and IgM in plasma. Additionally, RE showed a higher number of IgT-expressing cells in the gills and IgM-expressing cells in the spleen.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"161 ","pages":"Article 110282"},"PeriodicalIF":4.1,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143663079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The role of SYK phosphorylation in LPS-induced immunoglobulin responses of B cells in large yellow croaker (Larimichthys crocea)","authors":"Hongjun Xie ,&nbsp;Shuangshuang Cao ,&nbsp;Yueming Chen ,&nbsp;Zhiqiang Wang ,&nbsp;Xinhua Chen ,&nbsp;Zhengwei Cui","doi":"10.1016/j.fsi.2025.110283","DOIUrl":"10.1016/j.fsi.2025.110283","url":null,"abstract":"<div><div>Spleen tyrosine kinase (SYK), a non-receptor protein tyrosine kinase, is a key component of B cell receptor signaling and can regulate multiple physiological functions of B cells in mammals. In this study, a SYK gene was cloned and characterized from large yellow croaker (<em>Larimichthys crocea</em>) (<em>Lc</em>SYK), whose open reading frame consists of 1851 base pairs and encodes 616 amino acid residues. The predicted <em>Lc</em>SYK protein contains two N-terminal tandem Src homology 2 domains and a C-terminal tyrosine kinase catalytic domain, and shares a high amino acid sequence identity with SYK sequences in other vertebrate species. <em>Lc</em>SYK was mainly expressed in immune tissues, such as head kidney, trunk kidney, spleen, and gill. The mRNA expression of <em>Lc</em>SYK in primary head kidney leukocytes was not changed at 12, 24, and 48 h after lipopolysaccharide (LPS) stimulation. LPS stimulation upregulated the mRNA expression and protein production of IgM in IgM⁺ B cells, accompanied by an increase in the phosphorylation level, but not the total protein level, of <em>Lc</em>SYK. Moreover, when we used PRT062607 HCl to inhibit the phosphorylation of <em>Lc</em>SYK, both mRNA expression and protein production of IgM in IgM⁺ B cells were significantly suppressed. These results suggest that SYK phosphorylation may play a role in LPS-induced IgM production by IgM⁺ B cells, improving our understanding of the role of SYK in immunoglobulin responses of B cells in fish.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"161 ","pages":"Article 110283"},"PeriodicalIF":4.1,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143663084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative transcriptomic analysis of asymptomatic infected and symptomatic nervous necrosis virus infection in the natural state of golden pompano (Trachinotus ovatus)","authors":"Xiao Zhang ,&nbsp;Jia Cai ,&nbsp;Liqun Wang ,&nbsp;Yi Li ,&nbsp;Yu Huang ,&nbsp;Dapeng Yu ,&nbsp;Bei Wang ,&nbsp;Jichang Jian ,&nbsp;Huapu Chen","doi":"10.1016/j.fsi.2025.110284","DOIUrl":"10.1016/j.fsi.2025.110284","url":null,"abstract":"<div><div>Viral nervous necrosis is a significant threat to healthy fish culture, characterized by central nervous system and ocular lesions that involve critical immune mechanisms. The aim of this study was to elucidate the immune complexity associated with viral nervous necrosis to enhance understanding of the immune interactions between viral nervous necrosis and <em>Trachinotus ovatus</em>. In this study, bioinformatics techniques were used to analyze differentially expressed genes (DEGs) and immune-disease related pathways in the asymptomatically infected and symptomatic groups following a natural outbreak of viral nervous necrosis, and the DEGs identified in this study differentiated asymptomatically infected from symptomatic individuals, highlighting the importance of the immune response in the progression of the disease. Notably, gene ontology (GO) entries that were significantly upregulated in the brain tissue of the asymptomatically infected group included those related to the cellular response to cycloheximide, which inhibits the de novo synthesis of viral proteins, leading to viral death. The strong correlation between DEGs and immune response in this study clarifies the complex role of immunity in viral nervous necrosis and provides a data base for analyzing specific functions and pathways following outbreaks of this disease.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"161 ","pages":"Article 110284"},"PeriodicalIF":4.1,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143663077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In vitro and in vivo infection of snakehead rhabdovirus (SHRV) and recombinant chimeric SHRVs in Penaeus vannamei to evaluate availability as a vector for heterologous protein expression","authors":"Myoung Gwang Choi,&nbsp;Ki Hong Kim","doi":"10.1016/j.fsi.2025.110280","DOIUrl":"10.1016/j.fsi.2025.110280","url":null,"abstract":"<div><div>The development of viral vectors for heterologous protein expression in shrimp has been limited by the absence of stable shrimp cell lines capable of supporting consistent viral replication. This study addresses this critical challenge by exploring snakehead rhabdovirus (SHRV) as a potential vector that can propagate in fish-derived cell lines and simultaneously infect shrimp. Recombinant SHRVs (rSHRVs) expressing foreign proteins, including chimeric variants with glycoprotein substitutions from vesicular stomatitis virus (VSV) or spring viremia of carp virus (SVCV), were rescued through reverse genetic technology. <em>In vitro</em> experiments demonstrated that both native and chimeric rSHRVs effectively infected primary cultured lymphoid organ cells from <em>Penaeus vannamei</em>, resulting in the successful expression of reporter proteins. <em>In vivo</em> bioluminescence imaging (BLI) confirmed systemic expression of the foreign protein, with rSHRV-ALuc2 showing efficient infection and spread in shrimp tissues. Among the chimeric variants, rSHRV-ALuc2-G_VSV exhibited rapid initial infectivity but did not significantly outperform native rSHRV in prolonged replication. The use of SHRV, which propagates robustly in fish-derived EPC cells while maintaining infectivity in shrimp, represents a significant step towards overcoming the lack of shrimp cell lines for the development of heterologous protein expression tools using recombinant viruses. In the non-invasive route, while oral administration was unsuccessful partially due to viral instability in feed, reverse gavage demonstrated partial success with detectable viral loads but no bioluminescence signals. This study highlights the potential of SHRV as a versatile viral heterologous protein expression vector for shrimp. Further research is required to enhance infection and expression efficiencies and develop practical, non-invasive methods for broader application in aquaculture.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"161 ","pages":"Article 110280"},"PeriodicalIF":4.1,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel antimicrobial peptide Larimicin78-102 from large yellow croaker (Larimichthys crocea) shows potent antibacterial activity in vitro and enhances resistance to vibrio fluvialis infection in vivo","authors":"Zhenzhen Zhou ,&nbsp;Fangyi Chen ,&nbsp;Hua Hao ,&nbsp;Ke-jian Wang","doi":"10.1016/j.fsi.2025.110279","DOIUrl":"10.1016/j.fsi.2025.110279","url":null,"abstract":"<div><div>Antimicrobial peptides (AMPs) are considered a key component of innate immunity, playing a vital role in host defense. In the study, a novel functional gene, named <em>Larimicin</em>, was identified from large yellow croaker <em>Larimichthys crocea</em>. The <em>Larimicin</em> gene was widely distributed in multiple tissues of healthy <em>L</em>. <em>crocea</em> and was significantly induced in the liver after <em>Vibrio alginolyticus</em> or <em>Vibrio parahaemolyticus</em> infection. Larimicin_78-102, a truncated peptide derived from <em>Larimicin</em>, showed broad-spectrum antimicrobial activity and a binding affinity with LPS. It exhibited effective bactericidal activity against the common aquatic pathogens <em>Vibrio fluvialis</em>, <em>Pseudomonas fluorescens,</em> and <em>Pseudomonas putida</em>. It also showed anti-biofilm activity against three aquatic pathogens. Moreover, Larimicin_78-102 disrupted the integrity of the outer and inner membranes, resulting in ATP leakage and intracellular ROS accumulation, which ultimately led to bacterial cell death. Larimicin_78-102 exhibited good thermal stability and cation tolerance, with no obvious cytotoxicity or hemolytic activity. Notably, Larimicin_78-102 significantly improved the survival rate of <em>L</em>. <em>crocea</em> infected with <em>V</em>. <em>fluvialis</em>, raising it to 95 %, indicating its anti-infective role <em>in vivo</em>. In addition, Larimicin_78-102 significantly reduced the expression of the pro-inflammatory cytokines <em>TNF-α</em> and <em>IL-1β</em>, while up-regulating the anti-inflammatory factor <em>IL-</em>4 mRNA level. It also elevated the expression levels of <em>piscidin</em>, <em>hepcidin</em>, and <em>lysozyme</em>, as well as enhanced the enzymatic activity of lysozyme. Taken together, Larimicin_78-102 is a potential antibacterial agent for use in aquaculture to combat <em>V. fluvialis</em> infection diseases in the future.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"161 ","pages":"Article 110279"},"PeriodicalIF":4.1,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143633993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In vivo imaging to trace the dissemination of Aeromonas hydrophila in common carp (Cyprinus carpio) after intestinal infection","authors":"Yiran Wang,&nbsp;Yijie Li,&nbsp;Piao Wang,&nbsp;Chunchun Yang,&nbsp;Shaoyang Zhi,&nbsp;Chaobin Qi,&nbsp;Guoxing Nie,&nbsp;Junli Wang","doi":"10.1016/j.fsi.2025.110276","DOIUrl":"10.1016/j.fsi.2025.110276","url":null,"abstract":"<div><div><em>Aeromonas hydrophila</em> (<em>A. hydrophila</em>) is a pathogenic bacterium that often causes serious economic losses to aquaculture and fisheries. Its infection and pathogenesis of fish are currently not fully understood. In this study, <em>A. hydrophila</em> was labeled with Fluorescein Isothiocyanate (FITC) and administered to common carp via gavage to trace its dissemination in common carp (<em>Cyprinus carpio</em>) after intestinal infection by in vivo imaging system. The optimal FITC concentration for labeling was determined to be 30 μg/mL, with a labeling time of 3 h at a bacterial concentration of 10⁸ CFU/mL, with no significant impact on bacterial viability. The fluorescence imaging results of IVIS showed that FITC-Ah entered the internal organs through the carp intestine, first entering the kidneys and hepatopancreas (0.5 h after oral inoculation), and then the brain (around 10 h). Bacterial clearance occurred first in the hepatopancreas, followed by the brain, with the slowest clearance in the kidneys. Plate culture, <em>16S rRNA</em> sequencing, and comparison of clinical symptoms confirmed the reliability of the tracing results. At the molecular level, interleukin-6 (<em>il-6</em>) and interleukin-8 (<em>il-8</em>) showed an upregulation trend, while the expression of interleukin-10 (<em>il-10</em>) initially decreased and then increased in the kidneys, hepatopancreas, and spleen of common carp after oral infection. The results revealed that <em>A. hydrophila</em> can not only infect fish through the intestine, but also mainly invade the hepatopancreas, kidneys, and brain after entering the fish's body via the intestine. Furthermore, the clearance kinetics of <em>A. hydrophila</em> in the internal organs of fish show that it is first cleared from the hepatopancreas, followed by the brain, with the slowest clearance occurring in the kidneys.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"161 ","pages":"Article 110276"},"PeriodicalIF":4.1,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143633294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antiviral potential of the arctigenin derivative COA in reducing viral adhesion to the epithelial cell surface against IHNV infection","authors":"Yang Hu ,&nbsp;Huan Wang ,&nbsp;Zixuan Wang ,&nbsp;Xu Zhang ,&nbsp;Lei Liu ,&nbsp;Jiong Chen","doi":"10.1016/j.fsi.2025.110278","DOIUrl":"10.1016/j.fsi.2025.110278","url":null,"abstract":"<div><div>Infectious hematopoietic necrosis virus (IHNV) is a major aquaculture threat, highlighting the need for effective antiviral agents. This study evaluates the arctigenin derivative COA for its antiviral potential against IHNV. COA demonstrated no cytotoxicity to EPC cells at concentrations up to 10 μM and inhibited over 90 % of IHNV gene expression <em>in vitro</em>. It preserved normal nuclear morphology in infected cells, reduced viral titers, and completely blocked IHNV infection at 10 μM. Time-gradient assays identified COA's antiviral action during early infection, specifically inhibiting viral adsorption (82 %) and internalization (92 %). Using DiO-labeled IHNV particles, we visualized COA preventing viral entry into EPC cells, marking a novel finding for arctigenin derivatives. COA remained stable in water for over four days, enhancing its suitability for aquaculture applications. <em>In vivo</em>, COA improved survival rates of IHNV-infected rainbow trout by 46 % (injection) and 22 % (immersion) while significantly reducing IHNV gene expression and viral titers in spleen and kidney. It also upregulated interferon genes, activating antiviral responses and effectively reducing horizontal transmission of IHNV. These results highlight COA's potential as an antiviral agent, providing insights for developing targeted therapies against rhabdoviruses in aquaculture.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"161 ","pages":"Article 110278"},"PeriodicalIF":4.1,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143633293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hypoxia-induced mitochondrial dysfunction and mitophagy in the small yellow croaker (Larimichthys polyactis)","authors":"Lu Deng ,&nbsp;Jingqian Wang ,&nbsp;Yang Liu ,&nbsp;Li Wang ,&nbsp;Feng Liu ,&nbsp;Bao Lou ,&nbsp;Junquan Zhu","doi":"10.1016/j.fsi.2025.110275","DOIUrl":"10.1016/j.fsi.2025.110275","url":null,"abstract":"<div><div>Mitophagy serves as a pivotal mechanism for regulating the quantity and quality of mitochondria within cells, exerting significant influence on various processes such as cell differentiation, oxidative stress, inflammatory responses, and apoptosis. Currently, research on whether and how fish activate mitophagy under hypoxic stress conditions is still insufficient. In this study, to determine the mechanisms whereby marine fish adapt to hypoxic environments from the perspective of mitophagy, we used the small yellow croaker (<em>Larimichthys polyactis</em>) as the research subject and combined in <em>vivo</em> (liver) and in <em>vitro</em> (small yellow croaker fry [SYCF] cell line) hypoxic stress experiments. Fish exposed to hypoxic conditions were found to be characterized by liver tissue damage, and we detected significant elevations in the levels of hydrogen peroxide in liver tissues and reactive oxygen species (ROS) in SYCF cells, along with significant reductions in mitochondrial membrane potential. These findings thus indicate that hypoxic stress leads to tissue damage, excessive ROS production, and mitochondrial damage. In further experiments, we pre-treated SYCF cells with the antioxidant <em>N</em>-acetylcysteine, which was found to effectively reduce ROS levels and prevented the loss of mitochondrial membrane potential, thereby indicating that ROS play a crucial role in hypoxic stress-induced mitochondrial damage. Subsequently, to investigate whether hypoxic stress activates mitophagy to remove damaged mitochondria, we examined changes in the mRNA expression of mitophagy-related genes (<em>bnip3</em>, <em>lc3b</em>, <em>bnip3l</em>, <em>beclin1</em>, <em>fundc1</em>, and <em>ulk1</em>) in the liver and SYCF cells of <em>L. polyactis</em> exposed to hypoxic stress, and detected a significant upregulation of the mRNA expression of these genes. Furthermore, examination of liver ultrastructure and changes in the co-localization of mitochondria and lysosomes in SYCF cells revealed that hypoxic stress induces the formation of autophagosomes and autolysosomes in the liver, with an enhanced co-localization of mitochondria and lysosomes being observed after 6 h of hypoxia, which gradually increased with a prolongation of hypoxic exposure. We have, for the first time, exhibited the formation process of autophagosomes and the subsequent formation of autolysosomes in fish under hypoxic stress. These findings reveal the induction of mitophagy in <em>L. polyactis</em> in response to hypoxic stress, and indicate that these fish may initiate a mitophagic response to remove damaged mitochondria, reduce excessive ROS accumulation, and maintain cellular homeostasis. Our findings will not only lay a biological foundation for the breeding of hypoxia-tolerant strains of <em>L. polyactis</em> but also provide new insights into the mechanisms underlying the adaptation of marine fish to hypoxic environments.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"161 ","pages":"Article 110275"},"PeriodicalIF":4.1,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143630283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}