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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 -
Journal of Developmental Biology Oct 2021Brd2 belongs to the BET family of epigenetic transcriptional co-regulators that act as adaptor-scaffolds for the assembly of chromatin-modifying complexes and other...
Brd2 belongs to the BET family of epigenetic transcriptional co-regulators that act as adaptor-scaffolds for the assembly of chromatin-modifying complexes and other factors at target gene promoters. Brd2 is a protooncogene and candidate gene for juvenile myoclonic epilepsy in humans, a homeobox gene regulator in Drosophila, and a maternal-zygotic factor and cell death modulator that is necessary for normal development of the vertebrate central nervous system (CNS). As two copies of Brd2 exist in zebrafish, we use antisense morpholino knockdown to probe the role of paralog Brd2b, as a comparative study to Brd2a, the ortholog of human Brd2. A deficiency in either paralog results in excess cell death and dysmorphology of the CNS, whereas only Brd2b deficiency leads to loss of circulation and occlusion of the pronephric duct. Co-knockdown of both paralogs suppresses single morphant defects, while co-injection of morpholinos with paralogous RNA enhances them, suggesting novel genetic interaction with functional antagonism. Brd2 diversification includes paralog-specific RNA variants, a distinct localization of maternal factors, and shared and unique spatiotemporal expression, providing unique insight into the evolution and potential functions of this gene.
PubMed: 34842711
DOI: 10.3390/jdb9040046 -
Frontiers in Immunology 2020The effects of the oral administration of polysaccharide (RGP-1) on the immunoregulatory properties, antioxidant activity, and resistance against in L. were...
The effects of the oral administration of polysaccharide (RGP-1) on the immunoregulatory properties, antioxidant activity, and resistance against in L. were investigated. The purified RGP-1 (250, 500, and 1,000 μg/mL) was co-cultured with the head kidney cells of the common carp. The proliferation and phagocytosis activities of the head kidney cells, and the concentration of nitric oxide (NO) and cytokines in the culture medium were determined. Next, 300 common carps (47.66 ± 0.43 g) were randomly divided into five groups; the two control groups (negative and positive) were administered sterile PBS and the three treatment groups were administered different concentrations of RGP-1 (250, 500, and 1,000 μg/mL) for seven days. Subsequently, the positive and treatment groups were infected with , and the negative group was administered sterile PBS for 24 h. The concentration of NO, cytokines, lysozyme (LZM), and alkaline phosphatase (AKP) in serum, the total antioxidant capacity (T-AOC), the levels of malonaldehyde (MDA) and glutathione (GSH), and the total activities of superoxide dismutase (T-SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in the hepatopancreas of the common carp were tested. We observed that RGP-1 could significantly enhance the proliferation and phagocytosis activities ( < 0.05), besides inducing the production of NO, pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, IL-12) and anti-inflammatory cytokines (IL-10, TGF-β) ( < 0.05) . The experimental results revealed that RGP-1 significantly enhanced NO production, protein levels of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, IL-12), LZM and AKP activities, and the antioxidant content (T-AOC, SOD, CAT, GSH, GSH-Px, and MDA) compared to that observed in the negative group prior to infection ( < 0.05). NO, pro-inflammatory cytokines, LZM and AKP activities were significantly lower than that in the positive group after infection ( < 0.05). However, whether infected or not, the expression of anti-inflammatory cytokines (IL-10, TGF-β) increased significantly in the RGP-1-treated groups ( < 0.05). Therefore, the results suggested that RGP-1 could enhance the non-specific immunity, antioxidant activity and anti- activity of the common carp, and could be used as a safe and effective feed additive in aquaculture.
Topics: Administration, Oral; Aeromonas hydrophila; Animals; Anti-Bacterial Agents; Antioxidants; Carps; Cell Proliferation; Cells, Cultured; Cytokines; Gram-Negative Bacterial Infections; Head Kidney; Immunologic Factors; Nitric Oxide; Oxidative Stress; Phagocytosis; Polysaccharides; Rehmannia
PubMed: 32457762
DOI: 10.3389/fimmu.2020.00904 -
Scientific Reports Apr 2019The genetic regulation of nephron patterning during kidney organogenesis remains poorly understood. Nephron tubules in zebrafish are composed of segment populations that...
The genetic regulation of nephron patterning during kidney organogenesis remains poorly understood. Nephron tubules in zebrafish are composed of segment populations that have unique absorptive and secretory roles, as well as multiciliated cells (MCCs) that govern fluid flow. Here, we report that the transcription factor iroquois 2a (irx2a) is requisite for zebrafish nephrogenesis. irx2a transcripts localized to the developing pronephros and maturing MCCs, and loss of function altered formation of two segment populations and reduced MCC number. Interestingly, irx2a deficient embryos had reduced expression of an essential MCC gene ets variant 5a (etv5a), and were rescued by etv5a overexpression, supporting the conclusion that etv5a acts downstream of irx2a to control MCC ontogeny. Finally, we found that retinoic acid (RA) signaling affects the irx2a expression domain in renal progenitors, positioning irx2a downstream of RA. In sum, this work reveals new roles for irx2a during nephrogenesis, identifying irx2a as a crucial connection between RA signaling, segmentation, and the control of etv5a mediated MCC formation. Further investigation of the genetic players involved in these events will enhance our understanding of the molecular pathways that govern renal development, which can be used help create therapeutics to treat congenital and acquired kidney diseases.
Topics: Animals; Cell Differentiation; Organogenesis; Pronephros; Transcription Factors; Zebrafish; Zebrafish Proteins
PubMed: 31015532
DOI: 10.1038/s41598-019-42943-y -
Frontiers in Immunology 2021The intestine has many types of cells that are present mostly in the epithelium and lamina propria. The importance of the intestinal cells for the mammalian mucosal... (Comparative Study)
Comparative Study
The intestine has many types of cells that are present mostly in the epithelium and lamina propria. The importance of the intestinal cells for the mammalian mucosal immune system is well-established. However, there is no in-depth information about many of the intestinal cells in teleosts. In our previous study, we reported that adherent intestinal cells (AIC) predominantly express macrophage-related genes. To gather further evidence that AIC include macrophage-like cells, we compared their phagocytic activity and morphology with those of adherent head kidney cells (AKC), previously characterized as macrophage-like cells. We also compared equally abundant as well as differentially expressed mRNAs and miRNAs between AIC and AKC. AIC had lower phagocytic activity and were larger and more circular than macrophage-like AKC. RNA-Seq data revealed that there were 18309 mRNAs, with 59 miRNAs that were equally abundant between AIC and AKC. Integrative analysis of the mRNA and miRNA transcriptomes revealed macrophage heterogeneity in both AIC and AKC. In addition, analysis of AIC and AKC transcriptomes revealed functional characteristics of mucosal and systemic macrophages. Five pairs with significant negative correlations between miRNA and mRNAs were linked to macrophages and epithelial cells and their interaction could be pointing to macrophage activation and differentiation. The potential macrophage markers suggested in this study should be investigated under different immune conditions to understand the exact macrophage phenotypes.
Topics: Animals; Biodiversity; Cell Adhesion; Cell Communication; Cell Differentiation; Head Kidney; Intestines; Macrophage Activation; Macrophages; MicroRNAs; Phagocytosis; RNA, Messenger; Salmon; Sequence Analysis, RNA; Transcriptome
PubMed: 35003123
DOI: 10.3389/fimmu.2021.798156 -
Nephron 2019Nephron development involves the creation of discrete segment populations that are specialized to fulfill unique physiological roles. As such, renal function is reliant... (Review)
Review
Nephron development involves the creation of discrete segment populations that are specialized to fulfill unique physiological roles. As such, renal function is reliant on the proper execution of segment patterning programs. Despite the central importance of nephron segmentation, the genetic mechanisms that regulate this process are far from understood, in large part due to the experimental complexities and cost of interrogating these events in the mammalian metanephros. For this reason, forward genetics utilizing phenotypic screening in the zebrafish pronephros provides an avenue to gain novel insights about the mechanisms of nephron segmentation in the vertebrate kidney. Discoveries from zebrafish can highlight possible conserved pathways and provide a useful starting point for reverse genetic analyses with other animal models or in vitro approaches. In this review, we discuss the results of a novel chemical screen using the zebrafish to identify segmentation regulators. Through this screen, we identified for the first time that prostaglandin signaling can modulate nephron segmentation, and that it is normally requisite during development to mitigate segment fate choice in the embryonic kidney. We briefly discuss how these discoveries relate to current knowledge about nephron segmentation. Finally, we explore the possible implications of these findings for understanding renal ontogeny and disease, and how this knowledge may be useful for ongoing research initiatives that are aimed at deciphering how to build or rebuild the human kidney.
Topics: Animals; Humans; Kidney; Models, Animal; Nephrons; Organogenesis; Prostaglandins; Signal Transduction; Zebrafish
PubMed: 31216548
DOI: 10.1159/000501037 -
International Journal of Molecular... Feb 2024Cisplatin is an antineoplastic agent used to treat various tumors. In mammals, it can cause nephrotoxicity, tissue damage, and inflammation. The release of inflammatory...
Cisplatin is an antineoplastic agent used to treat various tumors. In mammals, it can cause nephrotoxicity, tissue damage, and inflammation. The release of inflammatory mediators leads to the recruitment and infiltration of immune cells, particularly neutrophils, at the site of inflammation. Cisplatin is often used as an inducer of acute kidney injury (AKI) in experimental models, including zebrafish (), due to its accumulation in kidney cells. Current protocols in larval zebrafish focus on studying its effect as an AKI inducer but ignore other systematic outcomes. In this study, cisplatin was added directly to the embryonic medium to assess its toxicity and impact on systemic inflammation using locomotor activity analysis, qPCR, microscopy, and flow cytometry. Our data showed that larvae exposed to cisplatin at 7 days post-fertilization (dpf) displayed dose-dependent mortality and morphological changes, leading to a decrease in locomotion speed at 9 dpf. The expression of pro-inflammatory cytokines such as interleukin , , and increased after 48 h of cisplatin exposure. Furthermore, while a decrease in the number of neutrophils was observed in the glomerular region of the pronephros, there was an increase in neutrophils throughout the entire animal after 48 h of cisplatin exposure. We demonstrate that cisplatin can have systemic effects in zebrafish larvae, including morphological and locomotory defects, increased inflammatory cytokines, and migration of neutrophils from the hematopoietic niche to other parts of the body. Therefore, this protocol can be used to induce systemic inflammation in zebrafish larvae for studying new therapies or mechanisms of action involving neutrophils.
Topics: Animals; Cisplatin; Zebrafish; Neutrophils; Larva; Acute Kidney Injury; Inflammation; Cytokines; Mammals
PubMed: 38397041
DOI: 10.3390/ijms25042363 -
Fish & Shellfish Immunology Apr 2020Neutrophils release nuclear chromatin decorated with antimicrobial proteins into the extracellular milieu as an innate immune defence mechanism to counter invading...
Neutrophils release nuclear chromatin decorated with antimicrobial proteins into the extracellular milieu as an innate immune defence mechanism to counter invading microbes. These chromatin structures, called extracellular traps (ETs) and released by a process called NETosis, have been detected in mammals, certain invertebrates and some fish species, including fathead minnow, zebrafish, common carp, turbot, sole and barramundi. However, there have been no previous studies of ETs in the Salmonidae. ETs are released in response to chemical and biological stimuli, but observations from different fish species are inconsistent, particularly regarding the potency of various inducers and inhibitors. Thus, this present study aimed to describe ET release in a salmonid (rainbow trout, Oncorhynchus mykiss (Walbaum, 1792)) and uncover the inducers and inhibitors that can control this response. Highly enriched suspensions of polymorphonuclear cells (PMNs; mainly neutrophils) were prepared from head kidney tissues by a triple-layer Percoll gradient technique. ET structures were visualised in PMN-enriched suspensions through staining of the chromatin with nucleic acid-specific dyes and immunocytochemical probing of characteristic proteins expected to decorate the structure. ET release was quantified after incubation with inducers and inhibitors known to affect this response in other organisms. Structures resembling ETs stained positively with SYTOX Green (a stain specific for nucleic acid) while immunocytochemistry was used to detect neutrophil elastase, myeloperoxidase and H2A histone in the structures, which are diagnostic proteinaceous markers of ETs. Consistent with other studies on mammals and some fish species, calcium ionophore and flagellin were potent inducers of ETs, while cytochalasin D inhibited NETosis. Phorbol 12-myristate 13-acetate (PMA), used commonly to induce ETs, exerted only weak stimulatory activity, while heat-killed bacteria and lipopolysaccharide did not induce ET release. Unexpectedly, the ET-inhibitor diphenyleneiodonium chloride acted as an inducer of ET release, an observation not reported elsewhere. Taken together, these data confirm for the first time that ETs are released by salmonid PMNs and compounds useful for manipulating NETosis were identified, thus providing a platform for further studies to explore the role of this mechanism in fish immunity. This new knowledge provides a foundation for translation to farm settings, since manipulation of the innate immune response offers a potential alternative to the use of antibiotics to mitigate against microbial infections, particularly for pathogens where protection by vaccination has yet to be realised.
Topics: Animals; Calcium Ionophores; Chromatin; Extracellular Traps; Flagellin; Head Kidney; Immunity, Innate; Neutrophils; Oncorhynchus mykiss; Vibrio; Vibrio Infections
PubMed: 31988016
DOI: 10.1016/j.fsi.2020.01.040 -
Disease Models & Mechanisms Jul 2023Little is known about the distal excretory component of the urinary tract in Danio rerio (zebrafish). This component is affected by many human diseases and disorders of...
Little is known about the distal excretory component of the urinary tract in Danio rerio (zebrafish). This component is affected by many human diseases and disorders of development. Here, we have undertaken multi-level analyses to determine the structure and composition of the distal urinary tract in the zebrafish. In silico searches identified uroplakin 1a (ukp1a), uroplakin 2 (upk2) and uroplakin 3b (upk3b) genes in the zebrafish genome (orthologues to genes that encode urothelium-specific proteins in humans). In situ hybridization demonstrated ukp1a expression in the zebrafish pronephros and cloaca from 96 h post-fertilization. Haematoxylin and Eosin staining of adult zebrafish demonstrated two mesonephric ducts uniting into a urinary bladder that leads to a distinct urethral opening. Immunohistochemistry identified Uroplakin 1a, Uroplakin 2 and GATA3 expression in zebrafish urinary bladder cell layers that match human urothelial expression. Fluorescent dye injections demonstrated zebrafish urinary bladder function, including urine storage and intermittent micturition, and a urethral orifice separate from the larger anal canal and rectum. Our findings reveal homology between the urinary tracts of zebrafish and humans, and offer the former as a model system to study disease.
Topics: Animals; Humans; Adult; Zebrafish; Membrane Glycoproteins; Uroplakin Ia; Uroplakin II; Urinary Bladder
PubMed: 37293698
DOI: 10.1242/dmm.050110