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Frontiers in Immunology 2020Nutrient digestibility, growth, and mucosal barrier status of fish skin, gills, and distal intestine were studied in Atlantic salmon fed feeds based on marine or...
Nutrient Digestibility, Growth, Mucosal Barrier Status, and Activity of Leucocytes From Head Kidney of Atlantic Salmon Fed Marine- or Plant-Derived Protein and Lipid Sources.
Nutrient digestibility, growth, and mucosal barrier status of fish skin, gills, and distal intestine were studied in Atlantic salmon fed feeds based on marine or plant-derived ingredients. The barrier status was assessed by considering the expression of four mucin genes, five genes that encode antimicrobial proteins, distal intestine micromorphology, and design-based stereology of the midgut epithelium. In addition, the head kidney leukocytes were examined using flow cytometry; to understand the differences in their counts and function. Five experimental feeds containing the main components i) fishmeal and fish oil (BG1), ii) soybean meal (BG2; to induce enteritis), iii) fishmeal as the main protein source and rapeseed oil as the main lipid source (BG3), iv) a mix of plant protein concentrates as the protein sources and fish oil as the lipid source (BG4), and v) plant and marine ingredients in the ratio 70:30 (BG5) were produced for the study. Atlantic salmon with initial weight 72.7 ± 1.2 g was offered the experimental feeds for 65 days. The results revealed that the weights of all fish groups doubled, except for fish fed BG2. Fish fed the BG2 diet had lower blood cholesterol concentration, developed enteritis, had lower expression of in the distal intestine, and had a compromised barrier status in the intestine. Expression of both the mucin genes and genes that encode antimicrobial peptides were tissue-specific and some were significantly affected by diet. The fish fed BG1 and BG3 had more head kidney lymphocyte-like cells compared to BG5-fed fish, and the phagocytic activity of macrophage-like cells from the head kidney was the highest in fish fed BG1. The intestinal micromorphology and the mucosal mapping suggest two different ways by which plant-based diets can alter the gut barrier status; by either reducing the mucous cell sizes, volumetric densities and barrier status (as noted for BG2) or increasing volumetric density of mucous cells (as observed for BG4 and BG5). The results of the compromised intestinal barrier in fish fed plant ingredients should be further confirmed through transcriptomic and immunohistochemical studies to refine ingredient composition for sustainable and acceptable healthy diets.
Topics: Animal Feed; Animals; Head Kidney; Intestinal Mucosa; Leukocytes; Plant Proteins; Salmo salar
PubMed: 33679713
DOI: 10.3389/fimmu.2020.623726 -
Kidney International Jan 2023The kidney is an essential organ that ensures bodily fluid homeostasis and removes soluble waste products from the organism. Nephrons, the functional units of the...
The kidney is an essential organ that ensures bodily fluid homeostasis and removes soluble waste products from the organism. Nephrons, the functional units of the kidney, comprise a blood filter, the glomerulus or glomus, and an epithelial tubule that processes the filtrate from the blood or coelom and selectively reabsorbs solutes, such as sugars, proteins, ions, and water, leaving waste products to be eliminated in the urine. Genes coding for transporters are segmentally expressed, enabling the nephron to sequentially process the filtrate. The Xenopus embryonic kidney, the pronephros, which consists of a single large nephron, has served as a valuable model to identify genes involved in nephron formation and patterning. Therefore, the developmental patterning program that generates these segments is of great interest. Prior work has defined the gene expression profiles of Xenopus nephron segments via in situ hybridization strategies, but a comprehensive understanding of the cellular makeup of the pronephric kidney remains incomplete. Here, we carried out single-cell mRNA sequencing of the functional Xenopus pronephric nephron and evaluated its cellular composition through comparative analyses with previous Xenopus studies and single-cell mRNA sequencing of the adult mouse kidney. This study reconstructs the cellular makeup of the pronephric kidney and identifies conserved cells, segments, and associated gene expression profiles. Thus, our data highlight significant conservation in podocytes, proximal and distal tubule cells, and divergence in cellular composition underlying the capacity of each nephron to remove wastes in the form of urine, while emphasizing the Xenopus pronephros as a model for physiology and disease.
Topics: Animals; Mice; Gene Expression Regulation, Developmental; Kidney; Kidney Glomerulus; Nephrons; RNA, Messenger; Xenopus laevis
PubMed: 36055600
DOI: 10.1016/j.kint.2022.07.027 -
Viruses Apr 2022Infectious hematopoietic necrosis virus (IHNV) is a pathogen that causes high rates of mortality in salmonid fishes. Therefore, an RNA-seq-based transcriptome analysis...
Infectious hematopoietic necrosis virus (IHNV) is a pathogen that causes high rates of mortality in salmonid fishes. Therefore, an RNA-seq-based transcriptome analysis was performed in the head kidney of rainbow trout infected with a highly virulent IHNV strain to understand the pathogenesis of and defense strategies for IHNV infection in rainbow trout. The results showed that the numbers of DEGs were 618, 2626, and 774 (control vs. IHNV) on days 1, 3, and 5, respectively. Furthermore, the enrichment analysis of gene ontology (GO) annotations to classify DEGs showed that GO terms considerably associated with DEGs were gluconeogenesis, inflammatory response, and cell adhesion in the Biological Process (BP) category, apical plasma membrane, extracellular matrix (ECM) in the Cellular Component category, and transporter activity, integrin binding, and protein homodimerization activity in the Molecular Function category, on days 1, 3, and 5, respectively. Notably, GO terms in the BP category, including the negative regulation of type I interferon production and positive regulation of interleukin-1β secretion, were commonly identified at all time points. In the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, complement and coagulation cascades were commonly identified at all time points. Importantly, the widely recognized GO terms and KEGG pathways extensively linked to DEGs were related to energy metabolism on day 1, the immune response on day 3, and cell proliferation on day 5. Furthermore, protein-protein interaction networks and centrality analysis showed that the metabolism and signaling transduction pathways were majorly upregulated. Conclusively, the virulent IHNV infection drives pathogenesis by activating the metabolic energy pathway for energy use for viral replication, facilitating necrosis through autophagy, and causing a shutoff response of the host immune system through the downregulation of type I IFN at the initial stage of infection.
Topics: Animals; Fish Diseases; Gene Expression Profiling; Head Kidney; Infectious hematopoietic necrosis virus; Oncorhynchus mykiss; RNA-Seq; Rhabdoviridae Infections
PubMed: 35632602
DOI: 10.3390/v14050859 -
International Journal of Molecular... Feb 2023is a Gram-positive bacterium and is considered a harmful aquaculture pathogen worldwide. In this study, strains were isolated from East Asian fourfinger threadfin fish...
is a Gram-positive bacterium and is considered a harmful aquaculture pathogen worldwide. In this study, strains were isolated from East Asian fourfinger threadfin fish () reared on a farm in Taiwan. A transcriptome analysis of the head kidney and spleen was performed in the fourfinger threadfin fish 1 day after infection using the Illumina HiSeq™ 4000 platform for RNA-seq to demonstrate the host immune mechanism against . A total of 7333 genes based on the KEGG database were obtained after the de novo assembly of transcripts and functional annotations. Differentially expressed genes (DEGs) (2-fold difference) were calculated by comparing the infection and phosphate-buffered saline control group gene expression levels in each tissue sample. We identified 1584 and 1981 differentially expressed genes in the head kidney and spleen, respectively. Based on Venn diagrams, 769 DEGs were commonly identified in both the head kidney and spleen, and 815 and 1212 DEGs were specific to the head kidney and spleen, respectively. The head-kidney-specific DEGs were enriched in ribosome biogenesis. The spleen-specific and common DEGs were found to be significantly enriched in immune-related pathways such as phagosome, Th1, and Th2 cell differentiation; complement and coagulation cascades; hematopoietic cell lineage; antigen processing and presentation; and cytokine-cytokine receptor interactions, based on the KEGG database. These pathways contribute to immune responses against infection. Inflammatory cytokines (IL-1β, IL-6, IL-11, IL-12, IL-35, and TNF) and chemokines (CXCL8 and CXCL13) were upregulated in the head kidney and spleen. Neutrophil-related genes, including phagosomes, were upregulated post-infection in the spleen. Our results could offer a strategy for the treatment and prevention of infection in fourfinger threadfin fish.
Topics: Animals; Fish Diseases; Fishes; Head Kidney; Spleen; Streptococcal Infections; Streptococcus iniae
PubMed: 36835242
DOI: 10.3390/ijms24043832 -
The Science of the Total Environment Jun 2024PFAAs (Perfluoroalkyl acids) are a class of bioaccumulative, persistent and ubiquitous environmental contaminants which primarily occupy the hydrosphere and its...
PFAAs (Perfluoroalkyl acids) are a class of bioaccumulative, persistent and ubiquitous environmental contaminants which primarily occupy the hydrosphere and its sediments. Currently, a paucity of toxicological information exists for short chain PFAAs and complex mixtures. In order to address these knowledge gaps, we performed a 3-week, aqueous exposure of rainbow trout to 3 different concentrations of a PFAA mixture (50, 100 and 500 ng/L) modeled after the composition determined in Lake Ontario. We conducted an additional set of exposures to individual PFAAs (25 nM each of PFOS (12,500 ng/L), PFOA (10,300 ng/L), PFBS (7500 ng/L) or PFBA (5300 ng/L) to evaluate differences in biological response across PFAA congeners. Untargeted proteomics and phosphorylated metabolomics were conducted on the blood plasma and head kidney tissue to evaluate biological response. Plasma proteomic responses to the mixtures revealed several unexpected outcomes including Similar proteomic profiles and biological processes as the PFOS exposure regime while being orders of magnitude lower in concentration and an atypical dose response in terms of the number of significantly altered proteins (FDR < 0.1). Biological pathway analysis revealed the low mixture, medium mixture and PFOS to significantly alter (FDR < 0.05) a number of processes including those involved in lipid metabolism, oxidative stress and the nervous system. We implicate plasma increases in PPARD and PPARG as being directly related to these biological processes as they are known to be important regulators in all 3 processes. In contrast to the blood plasma, the high mixture and PFOA exposure regimes caused the greatest change to the head kidney proteome, altering many proteins being involved in lipid metabolism, oxidative stress and inflammation. Our findings support the pleiotropic effect PFAAs have on aquatic organisms at environmentally relevant doses including those on PPAR signaling, metabolic dysregulation, immunotoxicity and neurotoxicity.
Topics: Animals; Water Pollutants, Chemical; Oncorhynchus mykiss; Fluorocarbons; Proteome; Head Kidney
PubMed: 38615763
DOI: 10.1016/j.scitotenv.2024.172389 -
Mechanisms of Development Mar 2020Claudins are a family of proteins which are the most important components of the tight junctions. The location of Claudins on the renal tubule epithelial determines its...
Claudins are a family of proteins which are the most important components of the tight junctions. The location of Claudins on the renal tubule epithelial determines its paracellular transport characteristics, but whether Claudins have other functions in kidneys remains still unclear. Here, we showed that the transcripts encoding two Claudin family proteins, claudin-7b (cldn-7b) and claudin-h (cldn-h), were expressed in the transporting cells in the zebrafish pronephros. By knocking down of cldn-7b and cldn-h in zebrafish, we showed that these claudins morphants exhibited cystic kidneys accompanied with body curvature. Further analysis showed that down regulation of cldn-7b or cldn-h led to multiple defects in apico-basolateral polarity, cilia morphology and ciliary function in kidney. Moreover, the ciliary defect was confirmed by depletion of Cldn-7b or Cldn-h using CRISPR/Cas9 system. We also showed that both cldn-7b and cldn-h were genetically interacted with a well-known ciliary gene, arl13b. Deletion of arl13b led to curly cilia in the pronephros that phenocopied with cldn-7b and cldn-h morphants. Taken together, our data suggested that the tight junction protein, Cldn-7b and Cldn-h, regulate kidney development and function by affecting cilia morphology.
Topics: Animals; Cilia; Claudins; Kidney; Organogenesis; Pronephros; Tight Junctions; Zebrafish
PubMed: 31887432
DOI: 10.1016/j.mod.2019.103595 -
Genomics Nov 2020Non-specific cytotoxic cells (NCC) are important cytotoxic leukocytes in teleost immune system. However, the NCC subsets have not been clarified. Thus, we create a...
Non-specific cytotoxic cells (NCC) are important cytotoxic leukocytes in teleost immune system. However, the NCC subsets have not been clarified. Thus, we create a comprehensive cell map of ~24,062 head kidney-derived leukocytes from Nile tilapia post poly I:C stimulation using single-cell RNA sequencing (scRNA-seq). Based on cell heterogeneity and known markers, the cells were classified into four cell types including B cell, T cell, NCC and monocytes/macrophages (Mo/MΦ). In the meantime, the regulatory network of NCC population was predicted by WGCNA and four hub genes (Stbd1, VWF, PGP, and GRN) and one transcription factor (Hvcn1) were identified. To further study the differentiation of NCC, four subsets including memory-like NCC, mature NCC, immature NCC, and pre-NCC were revealed in NCC population for the first time. Our data will provide new insight into the biology of NCC and enable more accurate functional and developmental analysis of NCC in immune system of lower vertebrates.
Topics: Animals; Cichlids; Cytotoxicity, Immunologic; Gene Regulatory Networks; Head Kidney; Leukocytes; RNA-Seq; Single-Cell Analysis
PubMed: 32971213
DOI: 10.1016/j.ygeno.2020.09.031 -
Fish & Shellfish Immunology Apr 2020Rab GTPases control trafficking of intracellular vesicles and are key regulators of endocytic and secretory pathways. Due to their specific distribution, they may serve...
Rab GTPases control trafficking of intracellular vesicles and are key regulators of endocytic and secretory pathways. Due to their specific distribution, they may serve as markers for different endolysosomal compartments. Since Rab GTPases are involved in uptake and trafficking of endocytosed ligands and cell receptors, as well as secretion of immune mediators, they have been implicated in diverse immunological processes and their functions are often exploited by intracellular pathogens such as viruses. While Rab proteins have been studied extensively in mammals, their functions in vesicle trafficking in teleosts are not well known. In the present work, Atlantic salmon Rab5c, Rab7a and Rab27a homologs were studied in terms of intracellular distribution and gene expression. Structured illumination microscopy demonstrated that transgenic, GFP-tagged salmon Rab5c and Rab7a are, predominantly, located within early endosomes and late endosomes/lysosomes, respectively. In contrast, Rab27a showed a broader distribution, which indicates that it associates with diverse intracellular vesicles and organelles. Infection of salmon with Salmonid alphavirus subtype 3 (SAV3) enhanced the mRNA levels of all of the studied Rab isoforms in heart and head kidney and most of them were upregulated in spleen. This may reflect the capacity of the virus to exploit the functions of these rab proteins. It is also possible that the transcriptional regulation of Rab proteins in SAV3-infected organs may play a role in the antiviral immune response. The latter was further supported by in vitro experiments with adherent head kidney leukocytes. The expression of Rab5c and Rab27a was upregulated in these cells following stimulation with TLR ligands including CpG oligonucleotides and polyI:C. The expression of most of the analyzed Rab isoforms in the primary leukocytes was also enhanced by stimulation with type I IFN. Interestingly, IFN-gamma had a negative effect on Rab7a expression which may be linked to the priming activity of this cytokine on monocytes and macrophages. Overall, these data demonstrate that the intracellular distribution of Rab5c, Rab7a and Rab27a is phylogenetically conserved within vertebrates and that these molecules might be implicated in viral infections and the regulation of the antiviral immune response in Atlantic salmon.
Topics: Alphavirus; Alphavirus Infections; Animals; Cells, Cultured; Endosomes; Fish Proteins; Gene Expression; Gene Expression Regulation; Head Kidney; Leukocytes; Lysosomes; Salmo salar; Sequence Homology; rab GTP-Binding Proteins; rab27 GTP-Binding Proteins; rab5 GTP-Binding Proteins
PubMed: 32014587
DOI: 10.1016/j.fsi.2020.01.058 -
International Journal of Molecular... Jan 2022Photobacteriosis is a septicaemic bacterial disease affecting several marine species around the globe, resulting in significant economic losses. Although many studies...
Photobacteriosis is a septicaemic bacterial disease affecting several marine species around the globe, resulting in significant economic losses. Although many studies have been performed related to the pathogen virulence and resistance factors, information regarding the host defence mechanisms activated once an infection takes place is still scarce. The present study was designed to understand innate immune responses of farmed juvenile gilthead seabream () after subsp. () infection. Therefore, two groups of seabream juveniles were intraperitoneally injected with 100 µL of PBS (placebo) or 100 µL of exponentially growing (1 × 10 CFU/mL; infected). The blood, plasma, liver, and head kidney of six fish from each treatment were sampled immediately before infection and 3, 6, 9, 24 and 48 h after infection for the broad screening of fish immune and oxidative stress responses. Infected animals presented marked anaemia, neutrophilia and monocytosis, conditions that are correlated with an increased expression of genes related to inflammation and phagocytic activity. Similar studies with different fish species and bacteria can be useful for the definition of health biomarkers that might help fish farmers to prevent the occurrence of such diseases.
Topics: Animals; Blood Cells; Fish Proteins; Gene Expression Regulation; Head Kidney; Immunity; Immunity, Humoral; Immunity, Innate; Oxidative Stress; Photobacterium; Sea Bream
PubMed: 35163486
DOI: 10.3390/ijms23031561 -
Frontiers in Immunology 2020Chemokine receptor and its ligand have evolved two paralogs in the teleost lineage. In this study, we have identified four duplicated and genes from hexaploid gibel... (Comparative Study)
Comparative Study
Chemokine receptor and its ligand have evolved two paralogs in the teleost lineage. In this study, we have identified four duplicated and genes from hexaploid gibel carp, , respectively. s and s were dynamically and differentially expressed in immune-related tissues, and significantly up-regulated in head kidney and spleen after crucian carp herpesvirus (HV) infection. Blocking Cxcr4/Cxcl12 axis by injecting AMD3100 brought more severe bleeding symptom and lower survival rate in HV-infected fish. AMD3100 treatment also suppressed the up-regulation of key antiviral genes in head kidney and spleen, and resulted in more acute replication of HV in . Consistently, the similar suppression of up-regulated expression of key antiviral genes were also observed in CAB cells treated by AMD3100 after poly(I:C) stimulation. Finally, MAPK3 and JAK/STAT were identified as the possible pathways that Cxcr4s and Cxcl12s participate in to promote the antiviral response in .
Topics: Amino Acid Sequence; Animals; Antiviral Agents; Base Sequence; Benzylamines; Carps; Chemokine CXCL12; Conserved Sequence; Cyclams; DNA, Complementary; Fish Diseases; Gene Duplication; Gene Expression Regulation; Head Kidney; Herpesviridae; Herpesviridae Infections; Organ Specificity; Phylogeny; Poly I-C; Polyploidy; Receptors, CXCR4; Sequence Alignment; Sequence Homology, Amino Acid; Signal Transduction; Spleen; Virus Replication
PubMed: 33013914
DOI: 10.3389/fimmu.2020.02176