Fish & shellfish immunology最新文献

{"title":"Comparison of transcriptome responses in blood cells of Atlantic salmon infected by three genotypes of Piscine orthoreovirus","authors":"Thomais Tsoulia ,&nbsp;Arvind YM. Sundaram ,&nbsp;Marit M. Amundsen ,&nbsp;Espen Rimstad ,&nbsp;Øystein Wessel ,&nbsp;Jorunn B. Jørgensen ,&nbsp;Maria K. Dahle","doi":"10.1016/j.fsi.2024.110088","DOIUrl":"10.1016/j.fsi.2024.110088","url":null,"abstract":"<div><div><em>Piscine orthoreovirus</em> (PRV) infection is common in aquaculture of salmonids. The three known PRV genotypes (PRV-1-3) have host species specificity and cause different diseases, but all infect and replicate in red blood cells (RBCs) in early infection phase. PRV-1 is the causative agent of heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon (<em>Salmo salar</em>), PRV-2 causes erythrocytic inclusion body syndrome (EIBS) in coho salmon (<em>Oncorhynchus kisutch</em>), while PRV-3 induces HSMI-like disease in farmed rainbow trout (<em>Oncorhynchus mykiss</em>). PRV-3 can also infect A. salmon without causing clinical disease and has been shown to cross-protect against PRV-1 infection and HSMI, while PRV-2 or inactivated adjuvanted PRV-1 vaccine only partially reduced HSMI pathologic changes. In the present work, we studied the transcriptional responses in blood cells of A. salmon two- and five-weeks post infection with PRV-1, PRV-2, PRV-3, or post injection with inactivated PRV-1 vaccine. PRV-1 and PRV-3 replicated well in A. salmon blood cells, and both induced the typical innate antiviral responses triggered by dsRNA viruses. Two weeks post infection, PRV-3 triggered stronger antiviral responses than PRV-1, despite their similar viral RNA replication levels, but after five weeks the induced responses were close to equal. PRV-2 and the InPRV-1 vaccine did not trigger the same typical antiviral responses as the replicating PRV-1 and PRV-3 genotypes, but induced genes involved in membrane trafficking and signaling pathways that may regulate physiological functions. These findings propose that the protection mediated by PRV-3 against a secondary infection by PRV-1 occur due to a potent and early activation of the same type of innate immune responses. The difference in the timing of antiviral responses may give PRV-1 an evolutionary edge, facilitating its dissemination to A. salmon heart, a critical step for HSMI development.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"157 ","pages":"Article 110088"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142812338","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 methyltransferase-like 3 (METTL3) in immune response modulation in bivalve (Mytilus coruscus) during bacterial infection","authors":"Xirui Si,&nbsp;Xinglu Chen,&nbsp;Baoying Guo,&nbsp;Zhi Liao,&nbsp;Xiaojun Yan,&nbsp;Pengzhi Qi","doi":"10.1016/j.fsi.2024.110094","DOIUrl":"10.1016/j.fsi.2024.110094","url":null,"abstract":"<div><div>N⁶-methyladenosine (m6A) modification is a prevalent mRNA modification that regulates diverse biological processes in eukaryotes, including immune responses. While the role of m6A in mammalian immunity has been explored, its involvement in the immune defense of invertebrates, particularly marine bivalves which face constant pathogen challenges, remains largely unknown. Here, we investigated the function of methyltransferase-like 3 (METTL3), a key m6A \"writer\" enzyme, in the immune response of the marine bivalve <em>Mytilus coruscus</em> against <em>Vibrio alginolyticus</em> infection. <em>M</em>. <em>coruscus</em> METTL3 (<em>Mc</em>METTL3) expression in the digestive gland increased (3-fold) after <em>V. alginolyticus</em> infection, coinciding with elevated m6A levels. Silencing <em>Mc</em>METTL3 reduced both m6A levels and <em>V. alginolyticus</em>-induced apoptosis in digestive gland cells. In silico analysis identified a C1q-like protein family member (<em>Mc</em>C1QL) as a potential downstream target of <em>Mc</em>METTL3, exhibiting an increase (7.2-fold) in m6A modification and an increase (1.5-fold) in expression during infection. Functional experiments confirmed that <em>Mc</em>C1QL knockdown inhibited <em>Mc</em>METTL3-driven apoptosis (10.83 %). These findings demonstrate that METTL3 regulates apoptosis and immune responses in invertebrates via m6A modification of target genes like <em>Mc</em>C1QL. This study provides novel insights into the m6A-mediated immune regulation mechanisms in marine bivalves and may offer potential avenues for developing innovative disease control strategies in aquaculture.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"157 ","pages":"Article 110094"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142881617","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":"m6A methylation dynamically participates in the immune response against Vibrio anguillarum in half-smooth tongue sole (Cynoglossus semilaevis)","authors":"Suxu Tan ,&nbsp;Wenwen Wang ,&nbsp;Sen Han ,&nbsp;Ruixue Zhang ,&nbsp;Kunpeng Shi ,&nbsp;Shaoqing Zang ,&nbsp;Zhendong Wu ,&nbsp;Zhenxia Sha","doi":"10.1016/j.fsi.2024.110101","DOIUrl":"10.1016/j.fsi.2024.110101","url":null,"abstract":"<div><div>N6-methyladenosine (m6A) is the most prevalent RNA modification and a multifaceted regulator capable of affecting various aspects of mRNA metabolism, thereby playing important roles in numerous physiological processes. However, it is still unknown whether, when, and to what extent m6A modulation are implicated in the immune response of an economically important aquaculture fish, half-smooth tongue sole (<em>Cynoglossus semilaevis</em>). Herein, we systematically profiled and characterized the m6A epitranscriptome and transcriptome in <em>C. semilaevis</em> after the infection of <em>Vibrio anguillarum</em>. We demonstrated that m6A could be modulated as early as 4-h post infection (hpi), and the overall intensity of m6A methylation was enhanced following infection. Both conservative and novel motifs were uncovered from the m6A modification sites. Furthermore, differentially m6A methylated genes (DMGs) and differentially expressed genes (DEGs) were identified, and functional enrichment revealed multiple immune-related pathways, especially the FoxO signaling pathway which showed significance in every comparison. Joint analysis highlighted the remarkedly dynamic role of m6A on gene expression, i.e. early on, m6A mainly prioritized the down-regulation of specific genes, and later, it switched gears to promote expression of another set of genes. Moreover, key candidate genes, mainly involved in immunity and energy metabolism, were identified. Validations were performed by qPCR and MeRIP-qPCR. To our limited knowledge, this is the first study comprehensively characterizing the global m6A atlas in aquaculture fish species. The presented results provide new insights into the dynamics of m6A modifications in the transcriptome of the half-smooth tongue sole following bacterial infection, and further studies are warranted to elucidate the functional significance of these changes in depth.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"157 ","pages":"Article 110101"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142893192","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":"SENP2 negatively regulates RIG-I/MDA5 mediated innate immunity in black carp","authors":"Yixia Chen ,&nbsp;Jun Li ,&nbsp;Jiaxin Fu ,&nbsp;Lili Xiao ,&nbsp;Jixiang Chu ,&nbsp;Wei Qin ,&nbsp;Jun Xiao ,&nbsp;Hao Feng","doi":"10.1016/j.fsi.2024.110097","DOIUrl":"10.1016/j.fsi.2024.110097","url":null,"abstract":"<div><div>Mammalian SUMO specific peptidase 2 (SENP2) plays vital roles in a variety of biological procedures including the immune response. However, the effects of teleost SENP2 are still mostly unexplored. In this study, the SENP2 of black carp (<em>Mylopharyngodon piceus</em>) was cloned and characterized. The open reading frame of black carp SENP2 (bcSENP2) consists of 1800 nucleotides, which encode 600 amino acids. The reporter assay results showed that over-expression of bcSENP2 alone had a weak effect on interferon (IFN) promoter transcription activity, whereas it significantly reduced bcMDA5/bcRIG-I mediated IFN promoter transcription activity. The interaction between bcSENP2 and bcMDA5 or bcRIG-I was detected by immunoprecipitation experiments. The plaque assay and qPCR results indicated that bcMDA5 or bcRIG-I mediated antiviral capacity was attenuated by bcSENP2, while knockdown of bcSENP2 led to enhanced antiviral resistance to SVCV in host cells. In addition, the expression level of bcMDA5/bcRIG-I protein was attenuated by co-expressed bcSENP2 and MG132 treatment rescued this attenuating effect. All of these data support the conclusion that bcSENP2 inhibits bcMDA5/bcRIG-I mediated antiviral signaling by enhancing ubiquitin-proteasome mediated degradation of bcMDA5/bcRIG-I in black carp.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"157 ","pages":"Article 110097"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142893243","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":"MALT1 promotes the antibacterial immune response by activating NF-κB signaling and enhancing hemocyte phagocytosis in the Chinese mitten crab","authors":"Guoqing Shen ,&nbsp;Guangyu Wang ,&nbsp;Jinming Chen ,&nbsp;Yanan Guo ,&nbsp;Wen Zhang ,&nbsp;Chaohui Xu ,&nbsp;Liqiao Chen ,&nbsp;Qun Wang","doi":"10.1016/j.fsi.2024.110100","DOIUrl":"10.1016/j.fsi.2024.110100","url":null,"abstract":"<div><div>Mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1), a scaffold protein, plays a pivotal role in the NF-κB pathway downstream of T-cell receptors (TCRs) and B-cell receptors (BCRs). As a key signaling hub, MALT1 integrates various pathways, making it essential for both innate and adaptive immunity. However, its role in the antibacterial immune responses of crustaceans remains unclear. Here, we characterized MALT1 from the Chinese mitten crab (<em>Eriocheir sinensis</em>), denoted as <em>Es</em>MALT1, and compared its sequence and domain conservation with MALT1 from other species. Furthermore, <em>Vibrio parahaemolyticus</em> infection upregulated <em>EsMALT1</em> expression markedly. Knockdown of <em>EsMALT1</em> in hemocytes inhibits the translocation of the NF-κB-like transcription factors <em>Es</em>Relish and <em>Es</em>Dorsal from the cytoplasm to the nucleus in response to <em>Vibrio parahaemolyticus</em> stimulation, thereby reducing the expression of the antimicrobial peptides anti-lipopolysaccharide factor (<em>ALF</em>), and <em>Crustins</em>. At the cellular level, silencing of <em>Es</em><em>MALT1</em> expression significantly inhibited the phagocytic capacity of crab hemocytes against <em>Vibrio parahaemolyticus. In vivo</em>, silencing of <em>Es</em><em>MALT1</em> rendered crabs susceptible to bacterial infection and impaired their bacterial clearance. In conclusion, <em>Es</em>MALT1 promotes both humoral and cellular immunity in <em>E. sinensis</em>, making it essential for the induction of antibacterial immune responses.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"157 ","pages":"Article 110100"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142902312","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":"FADD cooperates with Caspase-8 to positively regulate the innate immune response and promote apoptosis following bacterial infection in Japanese eel","authors":"Tianyu Wang ,&nbsp;Peng Lin ,&nbsp;Yilei Wang ,&nbsp;Yun Chen ,&nbsp;Ziping Zhang ,&nbsp;Fuyan Li ,&nbsp;Jianjun Feng","doi":"10.1016/j.fsi.2024.110110","DOIUrl":"10.1016/j.fsi.2024.110110","url":null,"abstract":"<div><div>Fas-associated protein with Death Domain (FADD) is a crucial signaling component of apoptosis and a vital immunomodulator on inflammatory signaling pathways. However, information on FADD-mediated apoptosis and immune regulation is limited in teleost. We herein cloned a FADD homolog, <em>Aj</em>FADD, from Japanese eel (<em>Anguilla japonica</em>). Expression analysis revealed that <em>Aj</em>FADD was significantly induced by LPS, poly I:C, and <em>Aeromonas hydrophila</em> infection <em>in vivo</em> and <em>in vitro</em>. The expression of <em>IFNs</em> and <em>IRFs</em>, <em>c-Rel</em> and <em>c-Fos</em>, <em>IL1</em> and <em>TNF-α</em>, and the essential antimicrobial peptide <em>LEAP-2</em> in Japanese eel liver cells was enhanced by overexpressing <em>Aj</em><em>FADD</em>, with a significant decrease of those genes following knockdown <em>Aj</em><em>FADD</em>. Luciferase activity assay, flow cytometry, and wound healing results showed that <em>Aj</em>FADD cooperated with <em>Aj</em>Caspase-8 to promote apoptosis of HEK293 cells and Japanese eel liver cells infected with <em>A. hydrophila</em>. Furthermore, <em>Aj</em>FADD and <em>Aj</em>Caspase-8 co-localized in the cytoplasm and displayed a direct protein-protein interaction by immunoprecipitation. Our results collectively showed that FADD cooperated with Caspase-8 to positively regulate the innate immune response and promote apoptosis in response to the <em>A. hydrophila</em> challenge in Japanese eel.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"157 ","pages":"Article 110110"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142926947","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":"Seaweed residue hydrolysate enhances the intestinal health, immunity and disease resistance in northern snakehead (Channa argus)","authors":"Minmin Wang ,&nbsp;Wenwen Wang ,&nbsp;Lei Guo ,&nbsp;Suxu Tan ,&nbsp;Hongtao Xue ,&nbsp;Ya Wang ,&nbsp;Xiao Cao ,&nbsp;Mengyang Chang ,&nbsp;Kunpeng Shi ,&nbsp;Yanzhao Nie ,&nbsp;Yingming Yang ,&nbsp;Zhenxia Sha","doi":"10.1016/j.fsi.2025.110115","DOIUrl":"10.1016/j.fsi.2025.110115","url":null,"abstract":"<div><div>Seaweed residue hydrolysate (SRH), produced by the acid hydrolysis of seaweed processing residues, is rich in bioactive compounds. The development and utilization of SRH as an aquatic immune enhancer not only achieves high-value utilization of waste but also promotes green and healthy aquaculture. In this study, northern snakehead (<em>Channa argus</em>) juveniles fed a compound feed supplemented with SRH (treatment group) exhibited a significant enhancement in intestinal microbial diversity and the proliferation of beneficial bacteria after eight weeks. After <em>Edwardsiella tarda</em> infection, the survival of the treatment group (70 %) was significantly higher than that in the control group (30 %). Histological analysis revealed that SRH alleviated tissue damage incurred by bacterial infection. Compared to the control group, the treatment group demonstrated an increase in the activities of non-specific immune enzymes and antioxidant enzymes, as well as a decrease in malondialdehyde (MDA). Furthermore, SRH influenced intestinal gene expression, with differentially expressed genes (DEGs) being enriched in various immune-related pathways, including cAMP, intestinal immune network for IgA production, and NF-κB signaling pathways. The present study has elucidated the potential efficacy of SRH in mitigating oxidative stress, enhancing the immunity and disease resistance of northern snakehead, providing valuable insights into the high-value utilization of SRH as a sustainable and eco-friendly immune enhancer in aquaculture.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"157 ","pages":"Article 110115"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142964342","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":"Molecular characterization, transcriptional profiling, and antioxidant activity assessment of nucleoredoxin (NXN) as a novel member of thioredoxin from red-lip mullet (Planiliza haematocheilus)","authors":"M.A.H. Dilshan ,&nbsp;W.K.M. Omeka ,&nbsp;H.M.V. Udayantha ,&nbsp;D.S. Liyanage ,&nbsp;D.C.G. Rodrigo ,&nbsp;G.A.N.P. Ganepola ,&nbsp;W.A.D.L.R. Warnakula ,&nbsp;H.A.C.R. Hanchapola ,&nbsp;Y.K. Kodagoda ,&nbsp;Jeongeun Kim ,&nbsp;Gaeun Kim ,&nbsp;Jihun Lee ,&nbsp;Qiang Wan ,&nbsp;Jehee Lee","doi":"10.1016/j.fsi.2024.110104","DOIUrl":"10.1016/j.fsi.2024.110104","url":null,"abstract":"<div><div>Nucleoredoxin (NXN) is a prominent oxidoreductase enzyme, classified under the thioredoxin family, and plays a pivotal role in regulating cellular redox homeostasis. Although the functional characterization of NXN has been extensively studied in mammals, its role in fish remains relatively unexplored. In this study, the <em>NXN</em> gene from <em>Planiliza haematocheilus</em> (<em>PhNXN</em>) was molecularly and functionally characterized using <em>in silico</em> tools, expression analyses, and <em>in vitro</em> assays. The predicted protein sequence of <em>PhNXN</em> contained 418 amino acids with an anticipated molecular mass of 47.53 kDa. It comprised a highly conserved ¹⁸⁸CPPC¹⁹¹ catalytic motif in the central NXN domain and two thioredoxin-like domains enriched with conserved Cys residues. PhNXN protein was primarily localized in the cytoplasm and nucleus of the cells. The spatial and temporal expression analyses of <em>PhNXN</em> mRNA showed the highest expression level in the brain under normal physiological conditions, while a significant modulation was detected in the blood and head kidney following immunostimulation with polyinosinic: polycytidylic acid, lipopolysaccharides, and <em>Lactococcus garvieae</em>. Recombinant PhNXN protein exhibited DPPH radical scavenging, thiol-dependent disulfide reduction, and cupric ion reduction activities. Additionally, PhNXN overexpression significantly suppressed oxidative stress-induced cell death, heavy metal cation-induced reactive oxygen species production, and viral hemorrhagic septicemia virus-induced cellular apoptosis in fish cells. Furthermore, PhNXN overexpression in RAW 264.7 cells demonstrated notable nitric oxide scavenging activity, M2-type polarization, and anti-inflammatory effect. Collectively, the overall findings of the study highlight the antioxidant and immunological functions of <em>PhNXN</em> in red-lip mullet.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"157 ","pages":"Article 110104"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142906811","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":"SIGIRR plays a dual role in zebrafish infected with Edwardsiella piscicida: Boosting digestive system wellness and mitigating inflammation","authors":"Ting Yu ,&nbsp;Shuo Yang ,&nbsp;Lifeng Zhang ,&nbsp;Dan Deng ,&nbsp;Xiao Zhang ,&nbsp;Kai Luo ,&nbsp;Weihua Gao ,&nbsp;Bei Wang ,&nbsp;Shuhuan Zhang ,&nbsp;Qiaoqing Xu","doi":"10.1016/j.fsi.2024.110105","DOIUrl":"10.1016/j.fsi.2024.110105","url":null,"abstract":"<div><div>Single immunoglobulin interleukin-1 receptor-associated protein (SIGIRR) negatively regulates the inflammatory response induced by bacterial infection by inhibiting the excessive synthesis of inflammatory mediators and overactivation. This inhibitory mechanism reduces the fish's susceptibility to pathogens and enhances survival rates. Zebrafish lacking the SIGIRR gene were generated using CRISPR/Cas9 gene knockout technology. In a zebrafish model infected with <em>Edwardsiella piscicida</em>, researchers found that SIGIRR gene deletion led to a significant increase in the activation of both inflammatory and anti-inflammatory factors. This deletion also resulted in intestinal villus epithelium damage, epithelial shedding, separation of the epithelium and lamina propria, and a severe reduction in goblet cells. After <em>E. piscicida</em> infection, the survival rate of SIGIRR^−/− zebrafish was significantly reduced, and the number of <em>E. piscicida</em> in the body was also significantly increased. Intestinal acid phosphatase activity in SIGIRR^−/− zebrafish was markedly elevated compared to wild-type (WT) zebrafish. Furthermore, the intestinal mucosal layer and villus thickness in SIGIRR^−/− zebrafish were reduced compared to WT zebrafish. The enzymatic activities of lipase and lysozyme in the intestines of SIGIRR^−/− zebrafish were significantly lower than in WT zebrafish. This study reveals the detrimental effects of SIGIRR gene deletion on the intestinal health of zebrafish, leading to decreased innate immune capacity and increased susceptibility to bacterial infections.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"157 ","pages":"Article 110105"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142913929","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":"Astragaloside IV can mitigate heat stress-induced tissue damage through modulation of the Keap1-Nrf2 signaling pathway in grass carp (Ctenopharyngodon idella)","authors":"Hua Liu ,&nbsp;Jingjing Feng ,&nbsp;Xiaoxue Bao ,&nbsp;Qi Wang ,&nbsp;Haiyi Yu ,&nbsp;Hui Yu ,&nbsp;Ying Yang","doi":"10.1016/j.fsi.2025.110121","DOIUrl":"10.1016/j.fsi.2025.110121","url":null,"abstract":"<div><div>This study investigated the potential protective effect of AS-IV against heat stress-induced tissue damage in grass carp (<em>Ctenopharyngodon idella</em>). Grass carp were injected intraperitoneally with 0, 2, 4, and 8 mg/kg of AS-IV for three consecutive days, and then subjected to heat stress (35 ± 0.5 °C); thereafter, histopathological analyses of the liver and spleen were performed at 0, 6, 24, and 48 h, respectively. The results indicated that sustained heat stress resulted in hemorrhage, vacuolization, increased hepatic blood sinusoidal space, inflammatory cell infiltration in the liver, and decreased number of melanomacrophage centers in the spleen; conversely, 4 and 8 mg/kg AS-IV attenuated the pathological symptoms induced by heat stress and mitigated tissue damage in the liver and spleen of grass carp. The possible mechanism is that AS-IV promotes Nrf2 signaling through the downregulation of <em>keap1a</em> and <em>keap1b</em>, thereby activating the Keap1–Nrf2 signaling pathway, leading to changes in the levels of protection-related genes in the liver (GSH-Px and CAT levels were elevated while MDA levels were decreased, and <em>gsh-px</em>, <em>cat</em>, <em>cu-zn sod</em>, and <em>hsp7</em>0 mRNA levels were upregulated while <em>il-</em>6 mRNA levels were downregulated) and spleen (GSH-Px, CAT, SOD, and GSH levels were increased while MDA levels were decreased, and <em>il-</em>6 mRNA levels were downregulated), which, in turn, improves the antioxidant ability of grass carp. Additionally, an appropriate dose of AS-IV transiently increased complement C3 levels after sustained heat stress, thereby improving the immunity of grass carp under heat stress. In conclusion, AS-IV can mitigate tissue damage induced in response to heat stress by modulating the redox homeostasis of grass carp and can be practically implemented in aquaculture sector.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"157 ","pages":"Article 110121"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143002449","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}