Search

The ion channels Piezo 1 and Piezo 2 have been identified as membrane mechano-proteins. Studying mechanosensitive channels in chemosensory organs could help in understanding the mechanisms by which these channels operate, offering new therapeutic targets for various disorders. This study investigates the expression patterns of Piezo proteins in zebrafish chemosensory organs. For the first time, Piezo protein expression in adult zebrafish chemosensory organs is reported. In the olfactory epithelium, Piezo 1 immunolabels kappe neurons, microvillous cells, and crypt neurons, while Calretinin is expressed in ciliated sensory cells. The lack of overlap between Piezo 1 and Calretinin confirms Piezo 1's specificity for kappe neurons, microvillous cells, and crypt neurons. Piezo 2 shows intense immunoreactivity in kappe neurons, one-ciliated sensory cells, and multi-ciliated sensory cells, with overlapping Calretinin expression, indicating its olfactory neuron nature. In taste buds, Piezo 1 immunolabels Merkel-like cells at the bases of cutaneous and pharyngeal taste buds and the light and dark cells of cutaneous and oral taste buds. It also marks the dark cells of pharyngeal taste buds and support cells in oral taste buds. Piezo 2 is found in the light and dark cells of cutaneous and oral taste buds and isolated chemosensory cells. These findings provide new insights into the distribution of Piezo channels in zebrafish chemosensory organs, enhancing our understanding of their sensory processing and potential therapeutic applications. [ABSTRACT FROM AUTHOR]

LIM homeobox 4 (LHX4) is a transcription factor crucial for anterior pituitary (AP) development. Patients with LHX4 mutation suffer from combined pituitary hormone deficiency (CPHD), short statures, reproductive and metabolic disorders and lethality in some cases. Lhx4-knockout (KO) mice fail to develop a normal AP and die shortly after birth. Here, we characterize a zebrafish lhx4-KO model to further investigate the importance of LHX4 in pituitary gland development and regulation. At the embryonic and larval stages, these fish express lower levels of tshb mRNA compared with their wildtype siblings. In adult lhx4-KO fish, the expressions of pituitary hormone-encoding transcripts, including growth hormone (gh), thyroid stimulating hormone (tshb), proopiomelanocortin (pomca) and follicle stimulating hormone (fshb), are reduced, the pomca promoter-driven expression in corticotrophs is dampened and luteinizing hormone (lhb)-producing gonadotrophs are severely depleted. In contrast to Lhx4-KO mice, Lhx4-deficient fish survive to adulthood, but with a reduced body size. Importantly, lhx4-KO males reach sexual maturity and are reproductively competent, whereas the females remain infertile with undeveloped ovaries. These phenotypes, which are reminiscent of those observed in CPHD patients, along with the advantages of the zebrafish for developmental genetics research, make this lhx4-KO fish an ideal vertebrate model to study the outcomes of LHX4 mutation. [ABSTRACT FROM AUTHOR]

Homotypic Fusion and Protein Sorting (HOPS) and Class C-core Vacuole/Endosome Tethering (CORVET) complexes regulate the correct fusion of endolysosomal bodies. Mutations in core proteins (VPS11, VPS16, VPS18, and VPS33) have been linked with multiple neurological disorders, including mucopolysaccharidosis (MPS), genetic leukoencephalopathy (gLE), and dystonia. Mutations in human Vacuolar Protein Sorting 16 (VPS16) have been associated with MPS and dystonia. In this study, we generated and characterized a zebrafish vps16(-/-) mutant line using immunohistochemical and behavioral approaches. The loss of Vps16 function caused multiple systemic defects, hypomyelination, and increased neuronal cell death. Behavioral analysis showed a progressive loss of visuomotor response and reduced motor response and habituation to acoustic/tap stimuli in mutants. Finally, using a novel multiple-round acoustic/tap stimuli test, mutants showed intermediate memory deficits. Together, these data demonstrate that zebrafish vps16(-/-) mutants show systemic defects, neurological and motor system pathologies, and cognitive impairment. This is the first study to report behavior abnormalities and memory deficiencies in a zebrafish vps16(-/-) mutant line. Finally, we conclude that the deficits observed in vps16(-/-) zebrafish mutants do not mimic pathologies associated with dystonia, but more align to abnormalities associated with MPS and gLE. [ABSTRACT FROM AUTHOR]

Phaeochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumours arising from chromaffin cells. Pathogenic variants in the gene succinate dehydrogenase subunit B (SDHB) are associated with malignancy and poor prognosis. When metastases arise, limited treatment options are available. The pathomechanism of SDHB-associated PPGL remains largely unknown, and the lack of suitable models hinders therapy development. Germline heterozygous SDHB pathogenic variants predispose to developing PPGLs with a life-long penetrance of around 50%. To mimic the human disease phenotype, we characterised adult heterozygous sdhb mutant zebrafish as a potential model to study SDHB-related PPGLs. Adult sdhb mutant zebrafish did not develop an obvious tumour phenotype and were anatomically and histologically like their wild-type siblings. However, sdhb mutants showed significantly increased succinate levels, a major hallmark of SDHB-related PPGLs. While basal activity was increased during day periods in mutants, mitochondrial complex activity and catecholamine metabolite levels were not significantly different. In conclusion, we characterised an adult in vivo zebrafish model, genetically resembling human carriers. Adult heterozygous sdhb mutants mimicked their human counterparts, showing systemic elevation of succinate levels despite the absence of a tumour phenotype. This model forms a promising basis for developing a full tumour phenotype and gaining knowledge of the pathomechanism behind SDHB-related PPGLs. [ABSTRACT FROM AUTHOR]

Liver regeneration induced by partial hepatectomy (PHx) has attracted intensive research interests due to the great significance for liver resection and transplantation. The zebrafish (Danio rerio) is an excellent model to study liver regeneration. In the fish subjected to PHx (the tip of the ventral lobe was resected), the lost liver mass could be fully regenerated in seven days. However, the regulatory mechanisms underlying the liver regeneration remain largely unknown. In this study, gene expression profiles during the regeneration of PHx-treated liver were explored by RNA sequencing (RNA-seq). The genes responsive to the injury of PHx treatment were identified and classified into different clusters based on the expression profiles. Representative gene ontology (GO) enrichments for the early responsive genes included hormone activity, ribosome biogenesis and rRNA processing, etc., while the late responsive genes were enriched in biological processes such as glutathione metabolic process, antioxidant activity and cellular detoxification. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichments were also identified for the differentially expressed genes (DEGs) between the time-series samples and the sham controls. The proteasome was overrepresented by the up-regulated genes at all of the sampling time points. Inhibiting proteasome activity by the application of MG132 to the fish enhanced the expression of Pcna (proliferating cell nuclear antigen), an indicator of hepatocyte proliferation after PHx. Our data provide novel insights into the molecular mechanisms underlying the regeneration of PHx-treated liver. [ABSTRACT FROM AUTHOR]

In zebrafish, like in mammals, radial glial cells (RGCs) can act as neural progenitors during development and regeneration in adults. However, the heterogeneity of glia subpopulations entails the need for different specific markers of zebrafish glia. Currently, fluorescent protein expression mediated by a regulatory element from the glial fibrillary acidic protein (gfap) gene is used as a prominent glia reporter. We now expand this tool by demonstrating that a regulatory element from the mouse Fatty acid binding protein 7 (Fabp7) gene drives reliable expression in fabp7-expressing zebrafish glial cells. By using three different Fabp7 regulatory element-mediated fluorescent protein reporter strains, we reveal in double transgenic zebrafish that progenitor cells expressing fluorescent proteins driven by the Fabp7 regulatory element give rise to radial glia, oligodendrocyte progenitors, and some neuronal precursors. Furthermore, Bergmann glia represent the almost only glial population of the zebrafish cerebellum (besides a few oligodendrocytes), and the radial glia also remain in the mature cerebellum. Fabp7 regulatory element-mediated reporter protein expression in Bergmann glia progenitors suggests their origin from the ventral cerebellar proliferation zone, the ventricular zone, but not from the dorsally positioned upper rhombic lip. These new Fabp7 reporters will be valuable for functional studies during development and regeneration. [ABSTRACT FROM AUTHOR]

Anaplastic thyroid cancer (ATC) is of the most aggressive thyroid cancer. While ATC is rare, it accounts for a disproportionately high number of thyroid cancer-related deaths. Here, we developed an ATC xenotransplant model in zebrafish larvae, where we can study tumorigenesis and therapeutic response in vivo. Using both mouse (T4888M) and human (C643)-derived fluorescently labeled ATC cell lines, we show these cell lines display different engraftment rates, mass volume, proliferation, cell death, angiogenic potential, and neutrophil and macrophage recruitment and infiltration. Next, using a PIP-FUCCI reporter to track proliferation in vivo, we observed cells in each phase of the cell cycle. Additionally, we performed long-term non-invasive intravital microscopy over 48 h to understand cellular dynamics in the tumor microenvironment at the single-cell level. Lastly, we tested two drug treatments, AZD2014 and a combination therapy of dabrafenib and trametinib, to show our model could be used as an effective screening platform for new therapeutic compounds for ATC. Altogether, we show that zebrafish xenotransplants make a great model to study thyroid carcinogenesis and the tumor microenvironment, while also being a suitable model to test new therapeutics in vivo. [ABSTRACT FROM AUTHOR]

Mycobacterium marinum , a fish pathogen, was originally used to model natural host–pathogen interactions in zebrafish. Recent studies have shown that infections caused by a wide range of nontuberculous mycobacteria (NTM) can be studied in zebrafish. Zebrafish larvae and adults represent valuable host species that can be used to model important biological questions underlying NTM pathogenesis and host immunity. Many pathophysiological traits discovered in the zebrafish model accurately recapitulate NTM infections in humans. The incidence of infections due to nontuberculous mycobacteria (NTM) has increased rapidly in recent years, surpassing tuberculosis in developed countries. Due to inherent antimicrobial resistance, NTM infections are particularly difficult to treat with low cure rates. There is an urgent need to understand NTM pathogenesis and to develop novel therapeutic approaches for the treatment of NTM diseases. Zebrafish have emerged as an excellent animal model due to genetic amenability and optical transparency during embryonic development, allowing spatiotemporal visualization of host–pathogen interactions. Furthermore, adult zebrafish possess fully functional innate and adaptive immunity and recapitulate important pathophysiological hallmarks of mycobacterial infection. Here, we report recent breakthroughs in understanding the hallmarks of NTM infections using the zebrafish model. [ABSTRACT FROM AUTHOR]

Wastewater treatment plant (WWTP) effluent often releases pharmaceuticals like venlafaxine (a serotonin–norephinephrine reuptake inhibitor antidepressant) to freshwater ecosystems at levels causing adverse metabolic effects on fish. Changes to fish metabolism can be regulated by epigenetic mechanisms like microRNA (small RNA molecules that regulate mRNA translation), including regulating mitochondrial mRNAs. Nuclear‐encoded microRNAs regulate mitochondrial gene expression in mammals, and have predicted effects in fish. We aimed to identify whether venlafaxine exposure changed mitochondrial respiration and resulted in differentially abundant mitochondrial microRNA (mitomiRs) in zebrafish brains. In vitro exposure of brain homogenate to below environmentally relevant concentrations of venlafaxine (<1 µg/L) caused a decrease in mitochondrial respiration, although this was not driven by changes to mitochondrial Complex I or II function. To identify whether these effects occur in vivo, zebrafish were exposed to 1 µg/L venlafaxine for 0, 1, 6, 12, 24, and 96 h. In vivo, venlafaxine exposure had no significant effects on brain mitochondrial respiration; however, select mitomiRs (dre‐miR‐301a‐5p, dre‐miR‐301b‐3p, and dre‐miR‐301c‐3p) were also measured, because they were bioinformatically predicted to regulate mitochondrial cytochrome c oxidase subunit I (COI) abundance. These mitomiRs were differentially regulated based on venlafaxine exposure (with miR‐301c‐3p abundance differing during the day and miR‐301b‐3p being lower in exposed fish at night), and with respect to sex and time sampled. Overall, the results demonstrated that in vitro venlafaxine exposure to zebrafish brain caused a decrease in mitochondrial respiration, but these effects were not seen after acute in vivo exposure. Results may have differed because in vivo exposure allows for fish to mitigate effects through mechanisms that could include mitomiR regulation, and because fish were only acutely exposed. Environ Toxicol Chem 2024;43:1569–1582. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

Numerous pharmaceutical and industrial chemicals are classified as endocrine‐disrupting chemicals (EDCs) that interfere with hormonal homeostasis, leading to developmental disorders and other pathologies. The synthetic estrogen 17α‐ethynylestradiol (EE2) is used in oral contraceptives and other hormone therapies. EE2 and other estrogens are inadvertently introduced into aquatic environments through municipal wastewater and agricultural effluents. Exposure of male fish to estrogens increases expression of the egg yolk precursor protein vitellogenin (Vtg), which is used as a molecular marker of exposure to estrogenic EDCs. The mechanisms behind Vtg induction are not fully known, and we hypothesized that it is regulated via DNA methylation. Adult zebrafish were exposed to either dimethyl sulfoxide or 20 ng/L EE2 for 14 days. Messenger RNA (mRNA) expression and DNA methylation were assessed in male zebrafish livers at 0, 0.25, 0.5, 1, 4, 7, and 14 days of exposure; and those of females were assessed at 13 days (n ≥ 4/group/time point). To test the persistence of any changes, we included a recovery group that received EE2 for 7 days and did not receive any for the following 7 days, in the total 14‐day study. Methylation of DNA at the vtg1 promoter was assessed with targeted gene bisulfite sequencing in livers of adult male and female zebrafish. A significant increase in vtg1 mRNA was observed in the EE2‐exposed male fish as early as 6 h. Interestingly, DNA methylation changes were observed at 4 days. Decreases in the overall methylation of the vtg1 promoter in exposed males resulted in levels comparable to those in female controls, suggesting feminization. Importantly, DNA methylation levels in males remained significantly impacted after 7 days post–EE2 removal, unlike mRNA levels. These data identify an epigenetic mark of feminization that may serve as an indicator of not only estrogenic exposure but also previous exposure to EE2. Environ Toxicol Chem 2024;43:1547–1556. © 2024 SETAC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA. [ABSTRACT FROM AUTHOR]

Aronia melanocarpa (Michaux) Elliot (chokeberry) is a natural medicinal plant with a rich content of phenolic compounds such as procyanidins, anthocyanins, and phenolic acids. Chokeberry fruits are gaining worldwide popularity due to the strong bioactivities of their phenolic constituents, such as antioxidant, anti-inflammatory, anticancer, and liver-protective effects. In the present study, total phenolic, flavonoid, and anthocyanin contents of chokeberry juice were determined via the Folin-Ciocalteu method, a spectrophotometric method based on AlCl3 complexation, and pH differential method, respectively. Anthocyanin content was determined as 1.14% (equivalent to cyanidin-3-glucoside), while phenolic and flavonoid contents were measured as 5060.87 and 331.03 mg per 100 g of freeze-dried juice (equivalent to gallic acid and quercetin), respectively. The hepatoprotective effects of chokeberry fruit juice were evaluated using a zebrafish in vivo model for acetaminophen (APAP)-induced liver injury. Zebrafish is an emerging in vivo liver injury model that enables hepatoprotective bioactivity screening of samples on live organisms. The APAP-induced liver injury model was established by treating zebrafish larvae with 5 mM APAP from 2 days post fertilization (dpf) to 5 dpf. The hepatoprotective effect of chokeberry was evaluated via exposure to 1, 10, and 100 µg/mL of fruit juice. While chokeberry fruit juice did not cause any toxicity up to 100 µg/mL, it successfully reduced the injury induced by APAP when applied at 1 µg/mL concentration. To our knowledge, this is the first report evaluating the hepatoprotective effects of chokeberry using zebrafish in vivo liver injury model. [ABSTRACT FROM AUTHOR]

Lipid conjugates have advanced the field of lipid-based nanomedicine by promoting active-targeting (ligand, peptide, antibody), stability (PEGylation), controlled release (lipoid prodrug), and probe-based tracking (fluorophore). Recent findings indicate lipid conjugates dissociating from nanomedicine upon encountering a biological environment. Yet, implications for (pre)clinical outcomes remain unclear. In this study, using the zebrafish model (Danio rerio), we investigated the fate of liposome-incorporated lipid fluorophore conjugates (LFCs) after intravenous (IV) administration. LFCs having a bilayer mismatch and relatively polar fluorophore revealed counter-predictive outcomes for Caelyx/Doxil (clearance vs. circulating) and AmBisome-like liposomes (scavenger endothelial cell vs. macrophage uptake). Findings on LFC (mis)match for Caelyx/Doxil-like liposomes were supported by translational intravital imaging studies in mice. Importantly, contradicting observations suggest to originate from LFC dissociation in vivo , which was investigated by Asymmetric Flow Field-Flow Fractionation (AF4) upon liposome-serum incubation in situ. Our data suggests that LFCs matching with the liposome bilayer composition – that did not dissociate upon serum incubation – revealed improved predictive outcomes for liposome biodistribution profiles. Altogether, this study highlights the critical importance of fatty acid tail length and headgroup moiety when selecting lipid conjugates for lipid-based nanomedicine. [Display omitted] [ABSTRACT FROM AUTHOR]

Goldenhar syndrome, a rare craniofacial malformation, is characterized by developmental anomalies in the first and second pharyngeal arches. Its etiology is considered to be heterogenous, including both genetic and environmental factors that remain largely unknown. To further elucidate the genetic cause in a five‐generation Goldenhar syndrome pedigree and exploit the whole‐exome sequencing (WES) data of this pedigree, we generated collapsed haplotype pattern markers based on WES and employed rare variant nonparametric linkage analysis. FBLN2 was identified as a candidate gene via analysis of WES data across the significant linkage region. A fbln2 knockout zebrafish line was established by CRISPR/Cas9 to examine the gene's role in craniofacial cartilage development. fbln2 was expressed specifically in the mandible during the zebrafish early development, while fbln2 knockout zebrafish exhibited craniofacial malformations with abnormal chondrocyte morphologies. Functional studies revealed that fbln2 knockout caused abnormal chondrogenic differentiation, apoptosis, and proliferation of cranial neural crest cells (CNCCs), and downregulated the bone morphogenic protein (BMP) signaling pathway in the zebrafish model. This study demonstrates the role of FBLN2 in CNCC development and BMP pathway regulation, and highlights FBLN2 as a candidate gene for Goldenhar syndrome, which may have implications for the selection of potential screening targets and the development of treatments for conditions like microtia‐atresia. [ABSTRACT FROM AUTHOR]

In the dynamic landscape of biomedical science, the pursuit of effective treatments for motor neuron disorders like hereditary spastic paraplegia (HSP), amyotrophic lateral sclerosis (ALS), and spinal muscular atrophy (SMA) remains a key priority. Central to this endeavor is the development of robust animal models, with the zebrafish emerging as a prime candidate. Exhibiting embryonic transparency, a swift life cycle, and significant genetic and neuroanatomical congruencies with humans, zebrafish offer substantial potential for research. Despite the difference in locomotion--zebrafish undulate while humans use limbs, the zebrafish presents relevant phenotypic parallels to human motor control disorders, providing valuable insights into neurodegenerative diseases. This review explores the zebrafish's inherent traits and how they facilitate profound insights into the complex behavioral and cellular phenotypes associated with these disorders. Furthermore, we examine recent advancements in high-throughput drug screening using the zebrafish model, a promising avenue for identifying therapeutically potent compounds. [ABSTRACT FROM AUTHOR]

All herbal medicines are reported to be safe and have better results in curing disabilities. Scoparia dulcis is known for its anti-inflammatory and antioxidant properties. This study has been executed to explore the neuroprotective effects of ethanolic extract of Scoparia dulcis (EESD) against acrylamide using adult zebrafish. The experimental period was 72 h. After fixing the optimum acrylamide concentration and EESD, the healthy adult fish were grouped into control, induction, and treatment. During the experimental period, behavioural changes such as memory and locomotion were observed in control and experimental groups using the T-maze experiment. After 72 h, the neuronal tissues were isolated from the grouped fishes and analysed for various biochemical and enzymatic assays. The mRNA of the HSP-70 gene in control and experimental groups was expressed using RT-PCR. The optimum dosages for acrylamide and EESD were found to be 0.75 mM and 20 µg/mL, respectively. Memory improvement was observed in S. dulcis-treated fish, compared to the acrylamide-treated group using the T-maze assay. The extract reduced the toxicity induced by acrylamide from the various biochemical and histopathological parameters. The result shows the potential neuroprotective effects of ethanolic extract of Scoparia dulcis (EESD) against acrylamide-induced neurotoxicity in adult zebrafish. Therefore, Scoparia dulcis is a potent neuroprotective agent. [ABSTRACT FROM AUTHOR]

Copyright of Acta Agriculturae Zhejiangensis is the property of Acta Agriculturae Zhejiangensis Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Coriander is a notable medicinal plant known for its diverse properties, including anti‐inflammatory, antioxidant, anticancer, analgesic, and anti‐diabetic effects. Despite its recognized health benefits, research on its nephroprotective properties is limited. This study aimed to investigate the potential nephroprotective properties of an aqueous extract derived from coriander leaves using an aristolochic acid‐intoxicated zebrafish model. To assess kidney abnormalities induced by aristolochic acid (AA), we utilized the transgenic line Tg(wt1b:egfp), which expresses green fluorescent protein (GFP) in the kidney. Our previous report indicated that AA exposure leads to acute renal failure in zebrafish characterized by kidney malformation and impaired renal function. However, pretreatment of coriander extract (CE) can mitigate kidney malformations induced by AA. In addition, CE pretreatment reduces the accumulation of red blood cells in the glomerular region. To verify the nephroprotective effects of CE, we analyzed renal function by measuring the glomerular filtration rate in zebrafish embryos. Results indicate that CE partially mitigates renal function impairment caused by AA exposure, suggesting its potential to attenuate AA‐induced renal failure. Mechanistically, pretreatment with CE reduces the expression of proinflammatory and proapoptotic genes induced by AA. This suggests that CE likely alleviates acute renal failure by reducing inflammation and apoptosis. As a result, we regard zebrafish as a valuable model for screening natural compounds that have the potential to alleviate AA‐induced nephrotoxicity. [ABSTRACT FROM AUTHOR]

Introduction: Post-ovulatory aging is a time-dependent deterioration of ovulated oocytes and a major limiting factor reducing the fitness of offspring. This process may lead to the activation of cell death pathways like apoptosis in oocytes. Methodology: We evaluated oocyte membrane integrity, egg developmental competency, and mRNA abundance of apoptosis-related genes by RT-qPCR. Oocytes from zebrafish Danio rerio were retained in vivo at 28.5°C for 24 h post-ovulation (HPO). Viability was assessed using trypan blue (TB) staining. The consequences of in vivo oocyte aging on the developmental competence of progeny were determined by the embryo survival at 24 h post fertilization, hatching, and larval malformation rates. Results: The fertilization, oocyte viability, and hatching rates were 91, 97, and 65% at 0 HPO and dropped to 62, 90, and 22% at 4 HPO, respectively. The fertilizing ability was reduced to 2% at 8 HPO, while 72% of oocytes had still intact plasma membranes. Among the apoptotic genes bcl-2 (b-cell lymphoma 2), bada (bcl2- associated agonist of cell death a), cathepsin D, cathepsin Z, caspase 6a, caspase 7, caspase 8, caspase 9, apaf1, tp53 (tumor protein p53), cdk1 (cyclin-dependent kinase 1) studied, mRNA abundance of anti-apoptotic bcl-2 decreased and proapoptotic cathepsin D increased at 24 HPO. Furthermore, tp53 and cdk1 mRNA transcripts decreased at 24 HPO compared to 0 HPO. Discussion: Thus, TB staining did not detect the loss of oocyte competency if caused by aging. TB staining, however, could be used as a simple and rapid method to evaluate the quality of zebrafish oocytes before fertilization. Taken together, our results indicate the activation of cell death pathways in the advanced stages of oocyte aging in zebrafish. [ABSTRACT FROM AUTHOR]

Introduction: Myo-inositol (MI) is the most abundant inositol found in nature. To date MI supplementation is reported to be effective in the treatment of polycystic ovary syndrome, it is also suggested to alleviate the symptoms of diabetes and neurodegenerative disorders, but to date no statistically significant effects of inositol on depressive and anxiety symptoms were proven. In the study of anxiolytic effects in zebrafish, we often use the thigmotaxis index measuring the ratio of the amount of time the animal spends near the walls compared to the entire arena. Aim: The objective of this paper was to examine the effect of MI on zebrafish embryos’ locomotor activity, as well as its potential anxiolytic activity in zebrafish larvae. Material and methods: In the first part of the experiment, the embryos were incubated with 5, 10, 20, and 40 mg/mL MI. 1-day post fertilization, embryo mobility was evaluated and burst activity was calculated. In the next part of the study, the behavior of 5-day-old larvae was tested. Results: Tests on embryo movement showed an increase in burst activity in the MI group at concentrations of 40 mg/mL (p < 0.0001) and a slight decrease in the group at concentrations of 10 mg/mL (p < 0.05). MI in the light/dark challenge had no impact on the thigmotaxis index. Conclusions: MI was shown to not affect stress reduction in zebrafish larvae. Further research on the potential of MI and other stereoisomers is needed. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Guangdong Pharmaceutical University is the property of Journal of Guangdong Pharmaceutical University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Environmental pollutants have been linked to neurotoxicity and are proposed to contribute to neurodegenerative disorders. The zebrafish model provides a high-throughput platform for large-scale chemical screening and toxicity assessment and is widely accepted as an important animal model for the investigation of neurodegenerative disorders. Although recent studies explore the roles of environmental pollutants in neurodegenerative disorders in zebrafish models, current knowledge of the mechanisms of environmentally induced neurodegenerative disorders is relatively complex and overlapping. This review primarily discusses utilizing embryonic zebrafish as the model to investigate environmental pollutants-related neurodegenerative disease. We also review current applicable approaches and important biomarkers to unravel the underlying mechanism of environmentally related neurodegenerative disorders. We found embryonic zebrafish to be a powerful tool that provides a platform for evaluating neurotoxicity triggered by environmentally relevant concentrations of neurotoxic compounds. Additionally, using variable approaches to assess neurotoxicity in the embryonic zebrafish allows researchers to have insights into the complex interaction between environmental pollutants and neurodegenerative disorders and, ultimately, an understanding of the underlying mechanisms related to environmental toxicants. [ABSTRACT FROM AUTHOR]

Copyright of Detergent & Cosmetics is the property of Detergent & Cosmetics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The ubiquitous use of insecticides leads to detrimental effects on non)target organisms due to accidental exposure. Neonicotinoid insecticides are popularly used worldwide for their high affinity for arthropod nicotinic receptors which effectively kill insect pests. Low affinity towards vertebrate nicotinic receptors, make them safer as compared to traditional insecticides. Recent studies demonstrated that neonicotinoid exposure can cause some toxicity in vertebrates including humans. Zebrafish is one of the popular model organisms to study ecotoxicity. This is the first study on adult zebrafish to report the effect of novel neonicotinoid, Clothianidin on mortality, liver antioxidant stress profile, liver function profile and brain acetylcholinesterase (AChE). Observations were made over two treatment periods, 96 hours, and 21 days, in five groups exposed to varying concentrations of Clothianidin viz. 30mg/L, 50mg/L, 70mg/L, 90mg/L, 110mg/L and a control. Although no mortality was observed, Clothianidin exposure led to increased activity of superoxide dismutase (SOD) enzyme, lipid peroxidation and decreased catalase (CAT), glutathione-S-transferase (GST). Treated groups also showed increased concentrations of liver enzyme alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP) and acid phosphatase (ACP). These results indicate that Clothianidin causes disturbances in the hepatic function. A prominent decreasing trend observed in brain AChE shows that Clothianidin inhibits AChE in adult zebrafish. Further investigations on DNA damage and gene expression studies could be conducted to understand the exact mechanism of action of Clothianidin at molecular level. [ABSTRACT FROM AUTHOR]

As ectotherms, fish are highly sensitive to temperature fluctuations, which can profoundly impact their reproductive cycles. In this study, we investigated the fertility and histological characteristics of zebrafish (Danio rerio) ovaries exposed to a temperature gradient ranging from the thermopreferendum temperature of the species, 27°C, to lower temperatures of 22°C, 20°C, and 13°C over a period of two weeks. Comparative metabolomic (six biological replicates for each temperature) and transcriptomic (four biological replicates for each temperature) analyses were conducted under the four temperature conditions. Results indicated that lower temperatures inhibited oocyte development and differential metabolites were involved in steroid hormone production, antioxidant function, and lipid and protein catabolism. Disrupted reproductive hormones, increased proteolysis, and lipid degradation significantly impeded oocyte development and egg maturation. Notably, a significant increase in bile acid content was noted in the ovaries of the cold-treated fish, indicating that bile acids play a critical role in ovarian failure. Overall, these findings provide valuable insights into the mechanisms governing the reproductive response of fish to cold stress. [ABSTRACT FROM AUTHOR]

Chronic treatment with clomipramine, a tricyclic antidepressant drug, reduces symptoms of obsessive-compulsive disorder (OCD) and can influence the activity of the hypothalamic-pituitary-adrenal axis. However, little is known regarding the effects of acute clomipramine on the immediate expression of stress responses. Serotonergic drugs can elicit surfacing, a behavioral profile potentially related to toxicity in fish, although surfacing has not yet been observed after clomipramine exposure. The present study investigated the impact of acute exposure to clomipramine on basal and stress-induced behaviors in the novel tank test and cortisol levels in mixed-sex, wild-type, adult zebrafish (Danio rerio). The findings show clomipramine-exposed groups (regardless of stress exposure) spent much more time in the top of the novel tank and had significantly less overall motor activity in the behavioral task compared to the fish not exposed to the drug. Then, the dose-dependent effects of acute clomipramine on activity in the surface of the novel tank (top third of the top half) were investigated further. Clomipramine dose-dependently increased surface-dwelling and elicited a dose-dependent hypoactivity in overall motor behavior. There were no statistically significant differences in whole-body cortisol levels in either experiment. Like other serotonin-acting drugs, clomipramine strongly elicited surface-dwelling and depressed motor behavior in adult zebrafish. Additional testing is needed to elucidate whether surfacing represents a toxic state and how serotonin regulates surfacing. [ABSTRACT FROM AUTHOR]

Nitrate and nitrite have emerged as increasingly common environmental pollutants, posing significant risks to various forms of life within ecosystems. To understand their impact on the visual system of zebrafish, adult zebrafish were exposed to environmentally relevant concentrations of nitrate (10 mg/L) and nitrite (1 mg/L) for 7 days. Visual behaviors were examined using optomotor and avoidance response. The eyeballs of the zebrafish were collected for H&E staining, IHC, and qPCR. Exposure decreased visual behavior and the thickness of most retinal layers. Exposure decreased expression of pax6a, pax6b, gpx1a, and bcl2a. Exposure increased expression of esr1, esr1a, esr2b, cyp19a1b, sod1a, nos2a, casps3, and tp53, and increased retinal brain aromatase expression by IHC. Collectively, our findings demonstrate that nitrate and nitrite exposure negatively impacted the visual system of adult zebrafish, highlighting the potential hazards of these environmental pollutants on aquatic organisms. [ABSTRACT FROM AUTHOR]

Centella asiatica (L.) Urban is a famous Chinese traditional medicine, which is widely used for treating various chronic inflammatory diseases. Although there are reports that Centella total glycosides exhibit heart‐protective properties, our previous experiment showed that it has cardiac toxic effects in zebrafish. The components of Centella total glycosides are complex, so we recommend further research to determine their key components and mechanisms. In this study, sample quantification was done using liquid chromatography–tandem mass spectrometry. The cardiotoxicity of Centella total glycosides, asiaticoside, madecassoside, asiatic acid, and madecassic acid was evaluated using zebrafish and cell models. The zebrafish oxidative stress model and myocarditis model were used to explore further the mechanisms through which cardiotoxicity is achieved. Asiatic acid and madecassic acid caused zebrafish cardiotoxicity and H9C2 cell death. However, no toxicity effects were observed for asiaticoside and madecassoside in zebrafish, until the solution was saturated. The results from the cell model study showed that asiatic acid and madecassic acid changed the expression of apoptosis‐related genes in myocardial cells. In the zebrafish model, high concentrations of these components raised the levels of induced systemic inflammation, neutrophils gathered in the heart, and oxidative stress injury. Asiatic acid and madecassic acid are the main components causing cardiotoxicity in zebrafish. This may be due to enhanced inflammation and reactive oxygen species injury, which causes myocardial cell apoptosis, which further leads to cardiac toxicity. As a famous traditional Chinese medicine, Centella asiatica (L.) Urban is used to treat various chronic inflammatory diseases. Our study found that Centella total glycoside has a cardiotoxic effect on zebrafish and evaluated Centella total glycosides, asiaticoside, madecassoside, asiatic acid, and madecassic acid. The result showed that asiatic acid and madecassic acid caused zebrafish cardiotoxicity and H9C2 cell death. At high concentrations, they would enhance inflammation and production of excessive reactive oxygen species in zebrafish, leading to cardiac toxicity. [ABSTRACT FROM AUTHOR]

The widespread use of carbamate pesticides has raised significant environmental and health concerns, particularly regarding water contamination and the disruption of defense systems in organisms. Despite these concerns, research on the differential impacts of pesticides on male and female organisms remains limited. This study focused on methomyl, investigating sex-specific differences in liver antioxidant defenses and inflammatory response indices in male and female zebrafish after 56 days of exposure to environmentally relevant concentrations (0, 0.05, 0.10, and 0.20 mg/L). Our findings indicate that methomyl exposure significantly increased ROS content in zebrafish livers, inducing oxidative stress and activating enzymatic antioxidant defenses such as SOD, CAT, and GSH-Px activities. Sub-chronic exposure altered the expression of apoptosis-related genes (Bax/Bcl2a and Caspases3a), resulting in liver cell apoptosis in a concentration-dependent manner, with the 0.20 mg/L concentration causing the most severe damage. Additionally, methomyl exposure at environmentally relevant concentrations triggered persistent inflammatory responses in liver tissues, evidenced by increased transcription levels of inflammatory factor genes and the activation of toll-like receptors, heightening susceptibility to exogenous allergens. It is noteworthy that oxidative damage indicators (AST, ROS, MDA) and inflammatory gene expressions (IL-1β, TNF-α) were significantly higher in female livers compared to male livers at 0.10–0.20 mg/L methomyl exposure. Consequently, our study underscores the potential adverse effects of environmental methomyl exposure on aquatic organisms and highlights the need for heightened consideration of the risks posed by environmental endocrine disruptors to female health and safety. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide is considered deleterious molecule that cause cellular damage integrity and function. Its key redox signaling molecule in oxidative stress and exerts toxicity on a wide range of organisms. Thus, to understand whether oxidative stress alters visual development, zebrafish embryos were exposed to H2O2 at concentration of 0.02 to 62.5 mM for 7 days. Eye to body length ratio (EBR) and apoptosis in retina at 48 hpf, and optomotor response (OMR) at 7 dpf were all measured. To investigate whether hydrogen peroxide-induced effects were mediated by oxidative stress, embryos were co-incubated with the antioxidant, glutathione (GSH) at 50 μM. Results revealed that concentrations of H2O2 at or above 0.1 mM induced developmental toxicity, leading to increased mortality and hatching delay. Furthermore, exposure to 0.1 mM H2O2 decreased EBR at 48 hpf and impaired OMR visual behavior at 7 dpf. Additionally, exposure increased the area of apoptotic cells in the retina at 48 hpf. The addition of GSH reversed the effects of H2O2, suggesting the involvement of oxidative stress. H2O2 decreased the expression of eye development-related genes, pax6α and pax6β. The expression of apoptosis-related genes, tp53, casp3 and bax, significantly increased, while bcl2α expression decreased. Antioxidant-related genes sod1, cat and gpx1a showed decreased expression. Expression levels of estrogen receptors (ERs) (esr1, esr2α, and esr2β) and ovarian and brain aromatase genes (cyp19a1a and cyp19a1b, respectively) were also significantly reduced. Interestingly, co-incubation of GSH effectivity reversed the impact of H2O2 on most parameters. Overall, these results demonstrate that H2O2 induces adverse effects on visual development via oxidative stress, which leads to alter apoptosis, diminished antioxidant defenses and reduced estrogen production. [ABSTRACT FROM AUTHOR]

Zebrafish possess the ability to regenerate dying neurons in response to retinal injury, with both Müller glia and microglia playing integral roles in this response. Resident Müller glia respond to damage by reprogramming and undergoing an asymmetric cell division to generate a neuronal progenitor cell, which continues to proliferate and differentiate into the lost neurons. In contrast, microglia become reactive, phagocytose dying cells, and release inflammatory signals into the surrounding tissue following damage. In recent years, there has been increased attention on elucidating the role that microglia play in regulating retinal regeneration. Here we demonstrate that inflammatory cytokines are differentially expressed during retinal regeneration, with the expression of a subset of pro-inflammatory cytokine genes upregulated shortly after light damage and the expression of a different subset of cytokine genes subsequently increasing. We demonstrate that both cytokine IL-1β and IL-10 are essential for Müller glia proliferation in the light-damaged retina. While IL-1β is sufficient to induce Müller glia proliferation in an undamaged retina, expression of IL-10 in undamaged retinas only induces Müller glia to express gliotic markers. Together, these findings demonstrate the essential role of inflammatory cytokines IL-1β and IL-10 on Müller glia proliferation following light damage in adult zebrafish. [ABSTRACT FROM AUTHOR]

Hexanucleotide repeat expansions within the gene C9ORF72 are the most common cause of the neurodegenerative diseases amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). This disease-causing expansion leads to a reduction in C9ORF72 expression levels in patients, suggesting loss of C9ORF72 function could contribute to disease. To further understand the consequences of C9ORF72 deficiency in vivo, we generated a c9orf72 mutant zebrafish line. Analysis of the adult female spinal cords revealed no appreciable neurodegenerative pathology such as loss of motor neurons or increased levels of neuroinflammation. However, detailed examination of adult female c9orf72-/- retinas showed prominent neurodegenerative features, including a decrease in retinal thickness, gliosis, and an overall reduction in neurons of all subtypes. Analysis of rod and cone cells within the photoreceptor layer showed a disturbance in their outer segment structure and rhodopsin mislocalization from rod outer segments to their cell bodies and synaptic terminals. Thus, C9ORF72 may play a previously unappreciated role in retinal homeostasis and suggests C9ORF72 deficiency can induce tissue specific neuronal loss. [ABSTRACT FROM AUTHOR]

Background: The key pathological signature of ALS/ FTLD is the mis-localization of endogenous TDP-43 from the nucleus to the cytoplasm. However, TDP-43 gain of function in the cytoplasm is still poorly understood since TDP-43 animal models recapitulating mis-localization of endogenous TDP-43 from the nucleus to the cytoplasm are missing. Methods: CRISPR/Cas9 technology was used to generate a zebrafish line (called CytoTDP), that mis-locates endogenous TDP-43 from the nucleus to the cytoplasm. Phenotypic characterization of motor neurons and the neuromuscular junction was performed by immunostaining, microglia were immunohistochemically localized by whole-mount tissue clearing and muscle ultrastructure was analyzed by scanning electron microscopy. Behavior was investigated by video tracking and quantitative analysis of swimming parameters. RNA sequencing was used to identify mis-regulated pathways with validation by molecular analysis. Results: CytoTDP fish have early larval phenotypes resembling clinical features of ALS such as progressive motor defects, neurodegeneration and muscle atrophy. Taking advantage of zebrafish's embryonic development that solely relys on yolk usage until 5 days post fertilization, we demonstrated that microglia proliferation and activation in the hypothalamus is independent from food intake. By comparing CytoTDP to a previously generated TDP-43 knockout line, transcriptomic analyses revealed that mis-localization of endogenous TDP-43, rather than TDP-43 nuclear loss of function, leads to early onset metabolic dysfunction. Conclusions: The new TDP-43 model mimics the ALS/FTLD hallmark of progressive motor dysfunction. Our results suggest that functional deficits of the hypothalamus, the metabolic regulatory center, might be the primary cause of weight loss in ALS patients. Cytoplasmic gain of function of endogenous TDP-43 leads to metabolic dysfunction in vivo that are reminiscent of early ALS clinical non-motor metabolic alterations. Thus, the CytoTDP zebrafish model offers a unique opportunity to identify mis-regulated targets for therapeutic intervention early in disease progression. [ABSTRACT FROM AUTHOR]

[Objective] To analyze the chemical constituents in 2 medicinal and edible homologous beverage (Xiangfeng Yueyan Drink and Shenqi Guyuan decoction), and evaluate the anti-oxidant and anti-fatigue effects. [Method] UHPLC-TQ-Orbitrap-MS mass spectrometer and reverse phase C₁ column were used to analyze the composition of the samples. The oxidative stress model established by aqueous menadione administration method was added with different gradient concentrations (25,50,100 µg/ml.) of Xiangfeng Yueyan Drink dilution. Meanwhile, group and a positive drug control group were set up. After treatment for 24 h, the Cell ROX was stained without light, and the fluorestype zebrafish and add different gradient concena normal cence intensity of yolk sac was calculated by fluorescence microscope. Select 5-day-old wild were set up at the same trations (25, 50, 100 µg/mL) of Shenqi Guyuan decoction diluent. A normal control group and a positive drug group . After treatment for 18 h, the fatigue model of zebrafish was established by aqueous solution of anhydrous sodium sulfite in the administratime 63 compounds were detected in Xiangfeng Yueyan Drink and 60 compounds were detected in Shengi Guyuan Drink. Compared with the model tion group, and the total movement distance of zebrafish was analyzed by behavior analyzer. [Result] According to the mass spectrometry data, group, the fluorescence intensity of zebrafish yolk sac significantly weakened under the intervention of Xiangfeng Yueyan Drink (P<0.01); compared with the model control group, the total movement distance of zebrafish under the intervention of Shenqi Guyuan Drink was significantly longer (P<0.05). [Conclusion] The 2 kinds of medicinal and edible homologous beverage have clear anti-oxidation and anti-fatigue effects respectively. [ABSTRACT FROM AUTHOR]

Neurons are post‐mitotic cells, with microtubules playing crucial roles in axonal transport and growth. Kinesin family member 2c (KIF2C), a member of the Kinesin‐13 family, possesses the ability to depolymerize microtubules and is involved in remodelling the microtubule lattice. Myocyte enhancer factor 2c (MEF2C) was initially identified as a regulator of muscle differentiation but has recently been associated with neurological abnormalities such as severe cognitive impairment, stereotyping, epilepsy and brain malformations when mutated or deleted. However, further investigation is required to determine which target genes MEF2C acts upon to influence neuronal function as a transcription regulator. Our data demonstrate that knockdown of both Mef2c and Kif2c significantly impacts spinal motor neuron development and behaviour in zebrafish. Luciferase reporter assays and chromosome immunoprecipitation assays, along with down/upregulated expression analysis, revealed that MFE2C functions as a novel transcription regulator for the Kif2c gene. Additionally, the knockdown of either Mef2c or Kif2c expression in E18 cortical neurons substantially reduces the number of primary neurites and axonal branches during neuronal development in vitro without affecting neurite length. Finally, depletion of Kif2c eliminated the effects of overexpression of Mef2c on the neurite branching. Based on these findings, we provided novel evidence demonstrating that MEF2C regulates the transcription of the Kif2c gene thereby influencing the axonal branching. [ABSTRACT FROM AUTHOR]

The neuropeptide vasopressin is known for its regulation of osmotic balance in mammals. Arginine vasotocin (AVT) is a non-mammalian homolog of this neuropeptide that is present in fish. Limited information suggested that vasopressin and its homologs may also influence reproductive function. In the present study, we investigated the direct effect of AVT on spermatogenesis, using zebrafish as a model organism. Results demonstrate that AVT and its receptors (avpr1aa, avpr2aa, avpr1ab, avpr2ab, and avpr2l) are expressed in the zebrafish brain and testes. The direct action of AVT on spermatogenesis was investigated using an ex vivo culture of mature zebrafish testes for 7 days. Using histological, morphometric, and biochemical approaches, we observed direct actions of AVT on zebrafish testicular function. AVT treatment directly increased the number of spermatozoa in an androgen-dependent manner, while reducing mitotic cells and the proliferation activity of type B spermatogonia. The observed stimulatory action of AVT on spermiogenesis was blocked by flutamide, an androgen receptor antagonist. The present results support the novel hypothesis that AVT stimulates short-term androgen-dependent spermiogenesis. However, its prolonged presence may lead to diminished spermatogenesis by reducing the proliferation of spermatogonia B, resulting in a diminished turnover of spermatogonia, spermatids, and spermatozoa. The overall findings offer an insight into the physiological significance of vasopressin and its homologs in vertebrates as a contributing factor in the multifactorial regulation of male reproduction. [ABSTRACT FROM AUTHOR]

Neurogenesis is the process by which new brain cells are formed. This crucial event emerges during embryonic life and proceeds in adulthood, and it could be influenced by environmental pollution. Non-combustion-derived magnetite represents a portion of the coarse particulate matter (PM) contributing to air and water pollution in urban settings. Studies on humans have reported that magnetite and other iron oxides have significant damaging effects at a central level, where these particles accumulate and promote oxidative stress. Similarly, magnetite nanoparticles can cross the placenta and damage the embryo brain during development, but the impact on neurogenesis is still unknown. Furthermore, an abnormal Fe cation concentration in cells and tissues might promote reactive oxygen species (ROS) generation and has been associated with multiple neurodegenerative conditions. In the present study, we used zebrafish as an in vivo system to analyze the specific effects of magnetite on embryonic neurogenesis. First, we characterized magnetite using mineralogical and spectroscopic analyses. Embryos treated with magnetite at sub-lethal concentrations showed a dose–response increase in ROS in the brain, which was accompanied by a massive decrease in antioxidant genes (sod2, cat, gsr, and nrf2). In addition, a higher number of apoptotic cells was observed in embryos treated with magnetite. Next, interestingly, embryos exposed to magnetite displayed a decrease in neural staminal progenitors (nestin, sox2, and pcna markers) and a neuronal marker (elavl3). Finally, we observed significative increases in apoeb (specific microglia marker) and interleukin-1b (il1b), confirming a status of inflammation in the brain embryos treated with magnetite. Our study represents the very first in vivo evidence concerning the effects of magnetite on brain development. [ABSTRACT FROM AUTHOR]

Macrophages play crucial and versatile roles in regulating tissue repair and regeneration upon injury. However, due to their complex compositional heterogeneity and functional plasticity, deciphering the nature of different macrophage subpopulations and unraveling their dynamics and precise roles during the repair process have been challenging. With its distinct advantages, zebrafish (Danio rerio) has emerged as an invaluable model for studying macrophage development and functions, especially in tissue repair and regeneration, providing valuable insights into our understanding of macrophage biology in health and diseases. In this review, we present the current knowledge and challenges associated with the role of macrophages in tissue repair and regeneration, highlighting the significant contributions made by zebrafish studies. We discuss the unique advantages of the zebrafish model, including its genetic tools, imaging techniques, and regenerative capacities, which have greatly facilitated the investigation of macrophages in these processes. Additionally, we outline the potential of zebrafish research in addressing the remaining challenges and advancing our understanding of the intricate interplay between macrophages and tissue repair and regeneration. [ABSTRACT FROM AUTHOR]

Background: Ototoxicity is a major side effect of many broadly used aminoglycoside antibiotics (AGs) and no FDA-approved otoprotective drug is available currently. The zebrafish has recently become a valuable model to investigate AG-induced hair cell toxicity and an expanding list of otoprotective compounds that block the uptake of AGs have been identified from zebrafish-based screening; however, it remains to be established whether inhibiting intracellular cell death pathway(s) constitutes an effective strategy to protect against AG-induced ototoxicity. Results: We used the zebrafish model as well as in vitro cell-based assays to investigate AG-induced cell death and found that ferroptosis is the dominant type of cell death induced by neomycin. Neomycin stimulates lipid reactive oxygen species (ROS) accumulation through mitochondrial pathway and blocking mitochondrial ferroptosis pathway effectively protects neomycin-induced cell death. We screened an alkaloid natural compound library and identified seven small compounds that protect neomycin-induced ototoxicity by targeting ferroptosis pathway: six of them are radical-trapping agents (RTAs) while the other one (ellipticine) regulates intracellular iron homeostasis, which is essential for the generation of lipid ROS to stimulate ferroptosis. Conclusions: Our study demonstrates that blocking intracellular ferroptosis pathway is an alternative strategy to ameliorate neomycin-induced ototoxicity and provides multiple hit compounds for further otoprotective drug development. [ABSTRACT FROM AUTHOR]

Huanglian Wendan Decoction (HWD) is a traditional Chinese medicine (TCM) prescribed to patients diagnosed with insomnia, which can achieve excellent therapeutic outcomes. As positively modulating the γ-aminobutyric acid (GABA) type A receptors (GABAARs) is the most effective strategy to manage insomnia, this study aimed to investigate whether the activation of GABAARs is involved in the anti-insomnia effect of HWD. We assessed the metabolites of HWD using LC/ MS and the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database and tested the pharmacological activity in vitro and in vivo using whole-cell patch clamp and insomnia zebrafish model. In HEK293 cells expressing α1β3γ2L GABAARs, HWD effectively increased the GABA-induced currents and could induce GABAAR-mediated currents independent of the application of GABA. In the LC-MS (QToF) assay, 31 metabolites were discovered in negative ion modes and 37 metabolites were found in positive ion modes, but neither three selected active metabolites, Danshensu, Coptisine, or Dihydromyricetin, showed potentiating effects on GABA currents. 62 active metabolites of the seven botanical drugs were collected based on the TCMSP database and 19 of them were selected for patch-clamp verification according to the virtual docking simulations and other parameters. At a concentration of 100 μM, GABA-induced currents were increased by (+)-Cuparene (278.80% ± 19.13%), Ethyl glucoside (225.40% ± 21.77%), and β-Caryophyllene (290.11% ± 17.71%). In addition, (+)-Cuparene, Ethyl glucoside, and β-Caryophyllene could also serve as positive allosteric modulators (PAMs) and shifted the GABA doseresponse curve (DRC) leftward significantly. In the PCPA-induced zebrafish model, Ethyl glucoside showed anti-insomnia effects at concentrations of 100 μM. In this research, we demonstrated that the activation of GABAARs was involved in the anti-insomnia effect of HWD, and Ethyl glucoside might be a key metabolite in treating insomnia. [ABSTRACT FROM AUTHOR]

Lamin A/C gene (LMNA) mutations contribute to severe striated muscle laminopathies, affecting cardiac and skeletal muscles, with limited treatment options. In this study, we delve into the investigations of five distinct LMNA mutations, including three novel variants and two pathogenic variants identified in patients with muscular laminopathy. Our approach employs zebrafish models to comprehensively study these variants. Transgenic zebrafish expressing wild-type LMNA and each mutation undergo extensive morphological profiling, swimming behavior assessments, muscle endurance evaluations, heartbeat measurement, and histopathological analysis of skeletal muscles. Additionally, these models serve as platform for focused drug screening. We explore the transcriptomic landscape through qPCR and RNAseq to unveil altered gene expression profiles in muscle tissues. Larvae of LMNA(L35P), LMNA(E358K), and LMNA(R453W) transgenic fish exhibit reduced swim speed compared to LMNA(WT) measured by DanioVision. All LMNA transgenic adult fish exhibit reduced swim speed compared to LMNA(WT) in T-maze. Moreover, all LMNA transgenic adult fish, except LMNA(E358K), display weaker muscle endurance than LMNA(WT) measured by swimming tunnel. Histochemical staining reveals decreased fiber size in all LMNA mutations transgenic fish, excluding LMNA(WT) fish. Interestingly, LMNA(A539V) and LMNA(E358K) exhibited elevated heartbeats. We recognize potential limitations with transgene overexpression and conducted association calculations to explore its effects on zebrafish phenotypes. Our results suggest lamin A/C overexpression may not directly impact mutant phenotypes, such as impaired swim speed, increased heart rates, or decreased muscle fiber diameter. Utilizing LMNA zebrafish models for drug screening, we identify l-carnitine treatment rescuing muscle endurance in LMNA(L35P) and creatine treatment reversing muscle endurance in LMNA(R453W) zebrafish models. Creatine activates AMPK and mTOR pathways, improving muscle endurance and swim speed in LMNA(R453W) fish. Transcriptomic profiling reveals upstream regulators and affected genes contributing to motor dysfunction, cardiac anomalies, and ion flux dysregulation in LMNA mutant transgenic fish. These findings faithfully mimic clinical manifestations of muscular laminopathies, including dysmorphism, early mortality, decreased fiber size, and muscle dysfunction in zebrafish. Furthermore, our drug screening results suggest l-carnitine and creatine treatments as potential rescuers of muscle endurance in LMNA(L35P) and LMNA(R453W) zebrafish models. Our study offers valuable insights into the future development of potential treatments for LMNA-related muscular laminopathy. [ABSTRACT FROM AUTHOR]

Many animals exhibit remarkable colors that are produced by the constructive interference of light reflected from arrays of intracellular guanine crystals. These animals can fine-tune their crystal-based structural colors to communicate with each other, regulate body temperature, and create camouflage. While it is known that these changes in color are caused by changes in the angle of the crystal arrays relative to incident light, the cellular machinery that drives color change is not understood. Here, using a combination of 3D focused ion beam scanning electron microscopy (FIB-SEM), micro-focused X-ray diffraction, superresolution fluorescence light microscopy, and pharmacological perturbations, we characterized the dynamics and 3D cellular reorganization of crystal arrays within zebrafish iridophores during norepinephrine (NE)-induced color change. We found that color change results from a coordinated 20° tilting of the intracellular crystals, which alters both crystal packing and the angle at which impinging light hits the crystals. Importantly, addition of the dynein inhibitor dynapyrazole-a completely blocked this NE-induced red shift by hindering crystal dynamics upon NE addition. FIB-SEM and microtubule organizing center (MTOC) mapping showed that microtubules arise from two MTOCs located near the poles of the iridophore and run parallel to, and in between, individual crystals. This suggests that dynein drives crystal angle change in response to NE by binding to the limiting membrane surrounding individual crystals and walking toward microtubule minus ends. Finally, we found that intracellular cAMP regulates the color change process. Together, our results provide mechanistic insight into the cellular machinery that drives structural color change. [ABSTRACT FROM AUTHOR]

Yeasts are the most important and widely used microorganisms used in the food industry, including the production of yeast powder and extract. Therefore, the present research was conducted with the aim of determining the effects of diet containing autolysed Saccharomyces cerevisiae yeast on innate immune function, liver metabolic enzymes, growth and survival of zebrafish. For this purpose, 480 pieces of zebra fish (10.78±0.08 g) were randomly placed in aquariums with a water volume of 40 liters for 60 days with different levels of autolyzed yeast in the basic diet including 1, 2 and 5% of the diet along with a control group (three replications) to 5% of body weight were fed. At the end of the feeding, to check survival and growth performance (final weight, percentage of body weight gain, food conversion ratio, specific growth rate, obesity ratio), biometry was done on all fish. In order to measure some of the serum's inherent immunity indicators, such as total immunoglobulin, total protein, albumin, and to check liver metabolic enzymes (alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase), fish were randomly sampled in order to prepare serum. 5 pieces of each aquarium). Data were analyzed using SPSS software through one-way analysis of variance. The results showed that feeding zebrafish with different levels of yeast isolates had no significant effect on the growth performance, survival percentage and liver enzymes of the treatment groups compared to the control group (P<0.05). However, the highest amount of total protein, total immunoglobulin and serum albumin was significantly in the treatment of feeding with autolysed yeast at the rate of 5% of the diet (P<0.05). In general, the results showed that the use of synthesized yeast, despite its effect on growth, liver enzymes and survival, could improve the innate immunity indicators in zebrafish. And the best suggested level in this research is 5% of autolysed yeast diet. [ABSTRACT FROM AUTHOR]

(1) Background: Roselle (Hibiscus sabdariffa) is a flowering plant reported to have anti-obesity, antioxidant, antibacterial, and anti-inflammatory effects. This study aims to evaluate the UV-absorbing and antioxidant activities of roselle aqueous extracts (RAE) and test the protective effects of RAE against UV radiation in zebrafish embryos. (2) Methods: DPPH assay and UV-spectrum methods were applied to evaluate the antioxidant and UV-absorbing activities, respectively. The protective effects of RAE were evaluated using fin morphology recording, Kaplan–Meier analysis, and Cox proportional hazards regression. Real-time PCR experiments were also applied to detect both the UV- and RAE-induced gene expressions. (3) Results: Our results show that (i) RAE had UV-absorbing abilities and significantly reduced ROS production in vitro; (ii) the mean times of malformed fins in the UV + RAE (36 and 48 ppm) groups were 3.56 and 4.44 days, respectively, and were prolonged compared to those in the UV-only group (3.36 days); (iii) zebrafish in the UV + RAE (36 and 48 ppm) groups were 0.963 and 0.496 (p < 0.001) times more likely to develop to malformed fins, respectively, than those in the UV-only group; and (iv) the RAE treatment led to the 0.19- to 0.62-fold downregulation of the p53, p21, mdm2, and bcl2 gene expressions, compared to the UV-only group. (4) Conclusions: The UV-protective effects of RAE might derive from both the in vitro UV-absorbing activity and in vivo regulation of the p53, p21, mdm2, and bcl2 gene expressions. [ABSTRACT FROM AUTHOR]

The pervasive utilization of plastics and their integration into ecosystems has resulted in significant environmental issues, particularly the pollution of microplastics (MPs). In aquaculture, high‐fat feed (HFD) is frequently employed to enhance the energy intake and economic fish production. This study utilized zebrafish as a model organism to investigate the impact of concurrent exposure to HFD and MPs on fish intestinal pathology damage and intestinal microbiome. The experimental design involved the division of zebrafish into two groups: one receiving a normal diet (ND) and the other receiving HFD. The zebrafish were exposed to a control group, as well as polystyrene (PS) MPs of varying sizes (5 and 50 μm). Histopathological examination revealed that the combination of 5 μm MPs and HFD resulted in the most significant damage to the zebrafish intestinal tract. Furthermore, gut microbiome assays indicated that exposure to MPs and HFD altered the composition of the gut microbiome. This study demonstrates that in aquaculture, the issue of HFD must be considered alongside concerns about MPs contamination, as both factors appear to have a combined effect on the intestinal pathology damage and intestinal microbiome. The findings of this research offer valuable insights for the improvement of fish farming practices. [ABSTRACT FROM AUTHOR]

Simple Summary: The gut microbiome, a complex microbial community, is intricately linked to the host's genetic background. The regulatory role of host genes on the microbiome has garnered considerable attention due to its impact not only on physiological and immune responses but also on the composition and functionality of intestinal microbes and the overall immune system. Nitric oxide synthase (NOS), through the production of nitric oxide (NO), participates in host defense, immune regulation, inflammatory responses, and autoimmune diseases. However, the effects of NOS on the composition and function of the zebrafish gut microbiota and the regulation of its homeostasis remain unclear. Genomic editing technologies have enabled the creation of zebrafish with specific genetic defects, making them a recognized model for studying host–microbiome–immune interactions. In this study, we characterized the impact of inducible nitric oxide synthase (iNOS) deficiency on the gut microbiota of zebrafish through 16S rRNA amplicon sequencing. Results revealed significant alterations in the microbial diversity and abundance in iNOS-deficient zebrafish, notably a reduction in Vibrio and an increase in Aeromonas. Transcriptomic sequencing of the gut confirmed functional changes, showing significant alterations in pathways related to the complement and coagulation cascades, PPAR signaling, cell adhesion molecules, Staphylococcus aureus infection, steroid synthesis, and bile acid synthesis. These pathways are crucial in pathogen clearance, inflammatory responses, and immune regulation, highlighting the significant role of the iNOS gene not only in microbial composition but also in gut immune and metabolic functions. The gut microbiota constitutes a complex ecosystem that has an important impact on host health. In this study, genetically engineered zebrafish with inducible nitric oxide synthase (iNOS or NOS2) knockout were used as a model to investigate the effects of nos2a/nos2b gene single knockout and nos2 gene double knockout on intestinal microbiome composition and function. Extensive 16S rRNA sequencing revealed substantial changes in microbial diversity and specific taxonomic abundances, yet it did not affect the functional structure of the intestinal tissues. Notably, iNOS-deficient zebrafish demonstrated a decrease in Vibrio species and an increase in Aeromonas species, with more pronounced effects observed in double knockouts. Further transcriptomic analysis of the gut in double iNOS knockout zebrafish indicated significant alterations in immune-related and metabolic pathways, including the complement and PPAR signaling pathways. These findings underscore the crucial interplay between host genetics and gut microbiota, indicating that iNOS plays a key role in modulating the gut microbial ecology, host immune system, and metabolic responses. [ABSTRACT FROM AUTHOR]

Early life stress (ELS) exposure alters stress susceptibility in later life and affects vulnerability to stress‐related disorders, but how ELS changes the long‐lasting responsiveness of the stress system is not well understood. Zebrafish provides an opportunity to study conserved mechanisms underlying the development and function of the stress response that is regulated largely by the neuroendocrine hypothalamus–pituitary–adrenal/interrenal (HPA/I) axis, with glucocorticoids (GC) as the final effector. In this study, we established a method to chronically elevate endogenous GC levels during early life in larval zebrafish. To this end, we employed an optogenetic actuator, beggiatoa photoactivated adenylyl cyclase, specifically expressed in the interrenal cells of zebrafish and demonstrate that its chronic activation leads to hypercortisolaemia and dampens the acute‐stress evoked cortisol levels, across a variety of stressor modalities during early life. This blunting of stress–response was conserved in ontogeny at a later developmental stage. Furthermore, we observe a strong reduction of proopiomelanocortin (pomc)‐expression in the pituitary as well as upregulation of fkbp5 gene expression. Going forward, we propose that this model can be leveraged to tease apart the mechanisms underlying developmental programming of the HPA/I axis by early‐life GC exposure and its implications for vulnerability and resilience to stress in adulthood. [ABSTRACT FROM AUTHOR]

Visualization of protein dynamics is a crucial step in understanding cellular processes. Chromobodies, fluorescently labelled singledomain antibodies, have emerged as versatile probes for live cell imaging of endogenous proteins. However, how these chromobodies behave in vivo and how accurately they monitor tissue changes remain poorly explored. Here, we generated an endothelial-specific β-catenin chromobody-derived probe and analyzed its expression pattern during cardiovascular development in zebrafish. Using highresolution confocal imaging, we show that the chromobody signal correlates with the localization of β-catenin in the nucleus and at cell-cell junctions, and thereby can be used to assess endothelial maturation. Loss of Cadherin 5 strongly affects the localization of the chromobody at the cell membrane, confirming the cadherin-based adherens junction role of β-catenin. Furthermore, using a genetic model to block blood flow, we observed that cell junctions are compromised in most endothelial cells but not in the endocardium, highlighting the heterogeneous response of the endothelium to the lack of blood flow. Overall, our data further expand the use of chromobodies for in vivo applications and illustrate their potential to monitor tissue morphogenesis at high resolution. [ABSTRACT FROM AUTHOR]

Thyroid dysgenesis (TD) is the common pathogenic mechanism of congenital hypothyroidism (CH). In addition, known pathogenic genes are limited to those that are directly involved in thyroid development. To identify additional candidate pathogenetic genes, we performed forward genetic screening for TD in zebrafish, followed by positional cloning. The candidate gene was confirmed in vitro using the Nthy-ori 3.1 cell line and in vivo using a zebrafish model organism. We obtained a novel zebrafish line with thyroid dysgenesis and identified the candidate pathogenetic mutation TATA-box binding protein associated Factor 1 (taf1) by positional cloning. Further molecular studies revealed that taf1 was needed for the proliferation of thyroid follicular cells by binding to the NOTCH1 promoter region. Knockdown of TAF1 impaired the proliferation and maturation of thyroid cells, thereby leading to thyroid dysplasia. This study showed that TAF1 promoted Notch signaling and that this association played a pivotal role in thyroid development. NEW & NOTEWORTHY: In our study, we obtained a novel zebrafish line with thyroid dysgenesis (TD) and identified the candidate pathogenetic mutation TATA-box binding protein associated Factor 1 (taf1). Further researches revealed that taf1 was required for thyroid follicular cells by binding to the NOTCH1 promoter region. Our findings revealed a novel role of TAF1 in thyroid morphogenesis. [ABSTRACT FROM AUTHOR]

In this review we describe different model organisms and systems that are commonly used to study syndromic disorders. Different use cases in modeling diseases, underlying pathomechanisms and specific effects of certain variants are elucidated. We also highlight advantages and limitations of different systems. Models discussed include budding yeast, the nematode worm, the fruit fly, the frog, zebrafish, mice and human cell-based systems. [ABSTRACT FROM AUTHOR]

The choroid plexues in the zebrafish hindbrain controls the exchange of substances between brain and its vessels, and the vascular abnormalities around the choroid plexues can lead to associated cerebrovascular diseases. We first performed serial imaging of the major blood vessels in the hindbrain region of zebrafish, and obtained a series of images of zebrafish between 43 hours and 63 hours after fertilization using confocal microscopy to photograph embryos under normal conditions and after cylindrospermopsin treatment. Afterwards, the DE-3D U-Net was developed for the segmentation of the hindbrain images. The segmentation results showed that the class pixel accuracy of DE-3D U-Net could reach to 86.67%, 93.18% and 83.74% for the three main vessels and the segmentation results were used to plot vascularization curves. The quantitative results showed that the radii of the three vessels showed a reduction of 18% after treatment with high concentrations of cylindrospermopsin, and the angle of the mesencephalic vein showed a reduction of 30° to 50°. This study proposed a neural network for segmentation of hindbrain vessels of zebrafish, and it provided a basis for research on the development of zebrafish choroid plexsus. [ABSTRACT FROM AUTHOR]