Search Results (368)

Cardiovascular diseases (CVDs) are the leading cause of death in the world. A total of 17.5 million people died of CVDs in the year 2012, accounting for 31% of all deaths globally. Vertebrate animal models have been used to understand cardiac disease biology, as the cellular, molecular, and physiological aspects of human CVDs can be replicated closely in these organisms. Zebrafish is a popular model organism offering an arsenal of genetic tools that allow the rapid in vivo analysis of vertebrate gene function and disease conditions. It has a short breeding cycle, high fecundity, optically transparent embryos, rapid internal organ development, and easy maintenance. This review aims to give readers an overview of zebrafish cardiac biology and a detailed account of heart development in zebrafish and its comparison with humans and the conserved genetic circuitry. We also discuss the contributions made in CVD research using the zebrafish model. The first part of this review focuses on detailed information on the morphogenetic and differentiation processes in early cardiac development. The overlap and divergence of the human heart’s genetic circuitry, structure, and physiology are emphasized wherever applicable. In the second part of the review, we overview the molecular tools and techniques available to dissect gene function and expression in zebrafish, with special mention of the use of these tools in cardiac biology. Full article

Hypophosphatasia (HPP) is a rare inborn error of metabolism caused by pathogenic variants in ALPL, coding for tissue non-specific alkaline phosphatase. HPP patients suffer from impaired bone mineralization, and in severe cases from vitamin B₆-responsive seizures. To study HPP, we generated alpl^-/- zebrafish using CRISPR/Cas9 gene-editing technology. At 5 days post fertilization (dpf), no alpl mRNA and 89% lower total alkaline phosphatase activity was detected in alpl^-/- compared to alpl^+/+ embryos. The survival of alpl^-/- zebrafish was strongly decreased. Alizarin red staining showed decreased bone mineralization in alpl^-/- embryos. B₆ vitamer analysis revealed depletion of pyridoxal and its degradation product 4-pyridoxic acid in alpl^-/- embryos. Accumulation of d3-pyridoxal 5′-phosphate (d3-PLP) and reduced formation of d3-pyridoxal in alpl^-/- embryos incubated with d3-PLP confirmed Alpl involvement in vitamin B₆ metabolism. Locomotion analysis showed pyridoxine treatment-responsive spontaneous seizures in alpl^-/- embryos. Metabolic profiling of alpl^-/- larvae using direct-infusion high-resolution mass spectrometry showed abnormalities in polyamine and neurotransmitter metabolism, suggesting dysfunction of vitamin B₆-dependent enzymes. Accumulation of N-methylethanolaminium phosphate indicated abnormalities in phosphoethanolamine metabolism. Taken together, we generated the first zebrafish model of HPP that shows multiple features of human disease and which is suitable for the study of the pathophysiology of HPP and for the testing of novel treatments. Full article

Zebrafish (Danio rerio) emerged as a suitable vertebrate model organism in the 1960s, owing to its transparent embryos and ease of breeding. Research utilizing zebrafish as a model organism gained significant momentum in the 1970s, particularly in the field of developmental biology. Over the years, zebrafish has become an indispensable model across various domains of biological research. However, conventional techniques for handling zebrafish in research settings have been limited by challenges related to survival rates, throughput, and imaging capabilities. The advancements in microfluidics and Micro-Electro-Mechanical Systems (MEMS) technology have addressed many of these challenges, enabling significant progress in zebrafish-based studies. The integration of microchannels, which ensure laminar flow for precise liquid handling, alongside microsensors and actuators for trapping mechanisms and high-resolution imaging, has greatly enhanced experimental efficiency and precision. This review provides a comprehensive analysis of very recent advancements in Fish-on-Chip (FOC) technologies, with a focus on their applications in zebrafish research, including trapping, imaging, transportation, and studies involving drug screening and disease modeling. Furthermore, we discuss recent efforts in retaining progressively motile zebrafish sperm, which is increasingly critical to meeting the rising demand for diverse zebrafish lines. Finally, we discuss an automated microfluidic-based fish farm developed using these technologies and conclude the review by highlighting potential future directions for Fish-on-Chip (FOC) technology. Full article

Background/Objectives: This study explores the bioactive potential of Bovistella utriformis biomass and its polysaccharides (PsBu) through comprehensive biochemical and bioactivity analyses, focusing on their antioxidant, cytotoxic, and antihyperglycemic properties. Methods: Elemental analysis determined the biomass’s chemical composition. Antioxidant activity was assessed using ABTS and DPPH assays. Monosaccharide composition was analyzed via gas chromatography-mass spectrometry (GC-MS). In vitro cytotoxicity assays were conducted on cancer and normal cell lines to determine IC₅₀ values and selectivity indices (SI). Zebrafish embryo toxicity was evaluated for teratogenic effects, and an in vivo antihyperglycemic study was performed in diabetic rat models. Results: The biomass exhibited high carbon content (around 41%) and nitrogen levels, with a balanced C/N ratio nearing 5. Protein content exceeded 50%, alongside significant carbohydrate, fiber, and ash levels. Antioxidant assays revealed inhibition rates of approximately 89% (ABTS) and 64% (DPPH). GC-MS analysis identified glucose as the predominant sugar (>80%), followed by galactose and mannose. Additionally, HPLC detected a photoprotective compound, potentially a mycosporin-like amino acid. Cytotoxicity assays demonstrated PsBu’s selective activity against colon, lung, and melanoma cancer cell lines (IC₅₀: 100–500 µg·mL⁻¹), while effects on normal cell lines were lower (IC₅₀ > 1300 µg·mL⁻¹ for HaCaT, >2500 µg·mL⁻¹ for HGF-1), with SI values approaching 27, supporting PsBu’s potential as a targeted anticancer agent. Zebrafish embryo assays yielded LC₅₀ values ranging from 1.4 to 1.8 mg·mL⁻¹. In vivo, PsBu reduced fasting blood glucose levels in hyperglycemic rats (approximately 210 mg·dL⁻¹ vs. 230 mg·dL⁻¹ in controls) and preserved pancreatic β-cell integrity (around 80% vs. 65% in controls). Conclusions: These findings suggest that B. utriformis biomass and PsBu exhibit strong antioxidant activity, selective cytotoxicity against cancer cells, and antihyperglycemic potential, making them promising candidates for further biomedical applications. Full article

In the frame of a “greener agriculture”, the development of new natural pesticides that are safer than their synthetic counterparts is gaining ground. Nonetheless, the origin of their nature does not necessarily imply their eco-friendliness. Hence, specific ecotoxicological studies are needed, with products being subjected to hazard and consequent risk assessment, for registration purposes. We have previously described on the strong nematicidal activity of Melia azedarach (chinaberry), Petroselinum crispum (parsley) and Eruca sativa (rocket) against the nematode Meloidogyne incognita. With this study the effect of the above-mentioned nematicidal botanicals on Eisenia fetida, Enchytraeus albidus, Daphnia magna and Danio rerio (Zebrafish) is reported, being all model organisms for the study of ecotoxicology of pesticides under registration. The implemented protocols are according to the OECD standards used for the evaluation of formulates under authorization. NOEC values were estimated to be higher than the highest concentrations assessed as recommended by OECD guidelines (≥1000 mg test item/kg dry soil). According to the presented results, all tested botanical nematicidals proved ecofriendly, not hindering the reproduction of juvenile worms of Eisenia fetida, and Enchytraeus albidus. Notably, Petroselinum crispum exhibited beneficial effects on reproduction of Eisenia fetida, as the number of juveniles increased. M. azedarach extract demonstrated moderate toxicity to zebrafish embryos (LC₅₀ was 51.41 ± 1.67 mg/L), yet it did not elicit adverse effects on the zebrafish liver. Thus, chinaberry, parsley and rocket are promising to be developed into new “green” nematicides. Full article

The aim of this review is to summarize the current knowledge on the use of coumarin-derived compounds in the zebrafish (Danio rerio) model. Coumarins, a class of naturally occurring compounds with diverse biological activities, including compounds such as coumarin, angelicin, and warfarin, have attracted considerable attention in the study of potential therapeutic agents for cancer, central nervous system disorders, and infectious diseases. The capabilities of coumarins as active compounds have led to synthesizing various derivatives with their own properties. While such variety is certainly promising, it is also cumbersome due to the large amount of research needed to find the most optimal compounds. The zebrafish model offers unique advantages for such studies, including high genetic and physiological homology to mammals, optical transparency of the embryos, and rapid developmental processes, facilitating the assessment of compound toxicity and underlying mechanisms of action. This review provides an in-depth analysis of the chemical properties of coumarins, their mechanisms of biological activity, and the results of previous studies evaluating the toxicity and efficacy of these compounds in zebrafish assays. The zebrafish model allows for a holistic assessment of the therapeutic potential of coumarin derivatives, offering valuable insights for advancing drug discovery and development. Full article

Lead (Pb) is a heavy metal associated with a range of toxic effects. Relatively few studies attempt to understand the impact of lead on development from a mechanistic perspective. Danio rerio (zebrafish) embryos are a model organism for studying the developmental consequences of exposure to chemical agents. This study examined the metabolome of developing zebrafish embryos exposed to 5 ppb, 15 ppb, 150 ppb, and 1500 ppb Pb concentrations during the first 24 h post fertilization, followed by 24 h of unexposed development and harvest at 48 h. Untargeted metabolomics and multivariate analysis revealed that various Pb exposures differentially affected the embryonic metabolome. Pathway analyses showed the dysregulation of biopterin, purine, alanine, and aspartate metabolism. Inductively coupled plasma mass spectrometry demonstrated Pb accumulation in embryos. Additionally, decreases in oxidation–reduction ratios were observed in 5–150 ppb groups but not in the 1500 ppb exposure group. This finding, along with several metabolite abundances, suggests a hormetic effect of Pb concentrations on the developing zebrafish metabolome. Together, these data reveal persistent global changes in the embryonic metabolome, pin-point biomarkers for Pb exposure, unveil dose-dependent relationships, and reflect Pb-induced changes in cellular energy. This work highlights aberrant processes and persistent changes underlying low-dose heavy metal exposure during early development. Full article

Liver tumors represent a serious clinical health problem that threatens human life. Previous studies have demonstrated that the pathogenesis of liver tumors is complex and influenced by various factors, highlighting limitations in both basic pathological research and clinical treatment. Traditional research methods often begin with the discovery of phenomena and gradually progress to the development of animal models and human trials. Among these, liver tumor animal models play a critical role in advancing related research. The zebrafish liver closely resembles the human liver in structure, function, and regenerative capacity. Additionally, the high transparency and rapid development of zebrafish embryos and larvae make them ideal model organisms for studying liver tumors. This review systematically summarizes recent methods for constructing zebrafish liver tumor models, including transplantation, transgenesis, induction, and gene knockout. Furthermore, the present paper explores the applications of these models in the study of liver cancer pathogenesis, metastasis, the tumor microenvironment, drug screening, and other related areas. By comparing the advantages and limitations of various models and integrating their distinct characteristics, this review provides insights for developing a novel liver tumor model that better aligns with clinical needs. This approach will offer valuable reference information for further in-depth studies of the pathological mechanisms of liver tumors and the development of new therapeutic drugs or strategies. Full article

Background: Amphotericin B (AmB) is a commonly utilized antifungal agent, which is also recommended for the treatment of certain neglected tropical diseases, including leishmaniasis. However, its clinical application is constrained because of its poor oral bioavailability and adverse effects, prompting the investigation of alternative drug delivery systems. Polymeric nanoparticles (PNPs) have gained attention as a potential drug delivery vehicle, providing advantages such as sustained release and enhanced bioavailability, and could have potential as AmB carriers. However, concerns persist regarding nanomaterials’ toxicity, requiring more studies. Zebrafish (Danio rerio) embryos were used as a valuable model for toxicity testing, especially because of their genetic similarity to humans and standardized developmental assessments. Methods: In this study, we produced and characterized AmB loaded and non-loaded PNPs by nanoprecipitation, dynamic light scattering, transmission electron microscopy, atomic force microscopy and spectroscopy. Afterwards, we verified their toxicity through in vitro MTT assays in three cell lines (HEK293, HepG2, and J774 A1) and in vivo tests with zebrafish embryos. Results: In both trials, it was noted that nanoencapsulation of the drug led to increased toxicity when compared to non-encapsulated AmB, possibly indicating that they penetrated the embryo’s chorion. Nevertheless, it was demonstrated that the polymers used are safe and they are not the cause of toxicity, neither are the nanostructures per se. Conclusions: Therefore, it is believed that the objective of improving the bioavailability of AmB may have been achieved, and the observed toxicity was probably linked to AmB’s ability to destabilize cell membranes. Full article

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by deficits in social skills and the presence of repetitive and restricted behaviors and interests. The social behavior of the zebrafish (Danio rerio) makes this organism a valuable tool for modeling ASD in order to explore the social impairment typical of this disorder. In addition to transgenic models, exposure of zebrafish embryos to valproic acid (VPA) has been found to produce ASD-like symptoms. This review first sets out to examine the existing literature on adult social behavior in the zebrafish VPA-induced model of autism, and the authors also aim to identify the ideal VPA dosage able to induce a persistent and long-lasting ASD-like phenotype while minimizing the suffering and distress of research animals in compliance with the principles of replacement, refinement, and reduction (3Rs). Full article

The increasing challenge of marine biofouling, mainly due to barnacle settlement, necessitates the development of effective antifoulants with minimal environmental toxicity. In this study, fifteen derivatives of brusatol were synthesized and characterized using ¹³C-NMR, ¹H-NMR, and mass spectrometry. All the semi-synthesized compounds obtained using the Multi-Target-Directed Ligand (MTDL) strategy, when evaluated as anti-settlement agents against barnacles, showed promising activity. Compound 3 exhibited the highest anti-settlement capacity, with an EC₅₀ value of 0.1475 μg/mL, an LC₅₀/EC₅₀ ratio of 42.2922 (>15 indicating low toxicity), and a resuscitation rate of 71.11%, while it showed no significant phenotypic differences in the zebrafish embryos after treatment for 48 h. The toxicity screening of zebrafish also demonstrated the low ecotoxicity of the selected compounds. Furthermore, homology modeling of the HSP90 structure was performed based on related protein sequences in barnacles. Subsequently, molecular docking studies were conducted on HSP90 using these newly synthesized derivatives. Molecular docking analyses showed that most activated derivatives displayed low binding energies with HSP90, aligning well with the biological results. They were found to interact with key residues in the binding site, specifically ARG243, TYR101, and LEU73. These computational findings are anticipated to aid in predicting the enzyme targets of the tested inhibitors and their potential interactions, thus facilitating the design of novel antifoulants in future research endeavors. Full article

Zebrafish (Danio rerio) have emerged as a valuable model organism for investigating musculoskeletal development and the pathophysiology of associated diseases. Key genes and biological processes in zebrafish that closely mirror those in humans, rapid development, and transparent embryos make zebrafish ideal for the in vivo studies of bone and muscle formation, as well as the molecular mechanisms underlying musculoskeletal disorders. This review focuses on the utility of zebrafish in modeling various musculoskeletal conditions, with an emphasis on bone diseases such as osteoporosis and osteogenesis imperfecta, as well as muscle disorders like Duchenne muscular dystrophy. These models have provided significant insights into the molecular pathways involved in these diseases, helping to identify the key genetic and biochemical factors that contribute to their progression. These findings have also advanced our understanding of disease mechanisms and facilitated the development of potential therapeutic strategies for musculoskeletal disorders. Full article

Acute and short-term toxicity tests are foundational to toxicology research. These tests offer preliminary insights into the fundamental toxicity characteristics of the chemicals under evaluation and provide essential data for chronic toxicity assessments. Fluoride is a common chemical in aquatic environments; however, the findings of toxicological data, such as LC₅₀ for aquatic organisms, often exhibit inconsistency. Consequently, this study employed zebrafish as a model organism during their early life stages to assess the acute and short-term toxicity of fluoride exposure. Bayesian model averaging was utilized to calculate the LC₅₀/EC₅₀ values and establish baseline concentrations. The results indicated a dose–response relationship between water fluoride concentration and harmful outcomes. The 20 mg/L group was identified as the lowest observed adverse effect level (LOAEL) for the majority of toxicity indicators and warrants special attention. Based on the BBMD model averages, the LC₅₀ of fluoride for 1 to 5 days post-fertilization (dpf) zebrafish was 147.00, 80.80, 61.25, 56.50, and 37.50 mg/L, while the EC₅₀ of cumulative malformation rate for 5 dpf zebrafish was 59.75 mg/L. As the benchmark response (BMR) increased, both the benchmark concentrations (BMCs) and benchmark dose levels (BMDLs) also increased. The research aims to provide essential data for the development of environmental water guidelines and to mitigate ecological risks associated with fluoride in aquatic ecosystems. Full article

Diafenthiuron is a novel derivative of thiourea and is highly toxic to non-target organisms, necessitating its efficient removal from wastewater before discharge. This study compared diafenthiuron removal efficiencies at a target concentration of 1 µM using three methods: a 4 mg/L ozone (O₃) treatment; an ultraviolet (UV) light treatment, applying UV₂₅₄ radiation with a fluence of 60 mJ/cm² for 10 min; and a combined O₃/UV treatment utilizing ozone and ultraviolet light. An acute toxicity assessment was conducted using a modeled zebrafish embryo (Danio rerio). The diafenthiuron removal efficiencies were 49.59%, 54.51%, and 68.90% for the UV light, O₃, and O₃/UV treatments, respectively. The treatments showed additional benefits of exerting no negative impacts on the survival rate, heart rate, or body length of the zebrafish larvae posttreatment. The survival and heart rates at 120 hpf, as well as the body length at 96 and 120 hpf, showed significant differences between the advanced oxidation and 1 μM diafenthiuron treatment groups. However, these parameters remained consistent with those of the control group. The three treatments alleviated the spatiotemporal downregulation of the liver-specific marker fabp10a caused by diafenthiuron exposure. The UV light and O₃/UV treatments were efficient at degrading diafenthiuron, causing decreased reactive oxygen species levels and increased pomc and prl expression levels. The O₃-treated diafenthiuron and 1 μM diafenthiuron treatments increased the reactive oxygen species levels and decreased the pomc and prl expression levels. The combined O₃/UV treatment showed the highest removal efficiency and the least toxicity, making it the most effective method for diafenthiuron degradation. This study provides valuable insights into the treatment of diafenthiuron-laden wastewater. Full article

Background/Objectives: Only 20–30% of oesophageal adenocarcinoma (OAC) patients achieve a complete response to neoadjuvant chemo-radiotherapy for locally advanced tumours. Enhancing the response to radiation therapy is critical for improving outcomes in this aggressive cancer. Pyrazinib (P3) is a promising compound with radiosensitizing, anti-angiogenic, anti-inflammatory, and anti-metabolic properties. However, its limited solubility and bioavailability have hindered its therapeutic potential. Methods: To overcome these limitations, pyrazinib was conjugated with gold nanoparticles (AuNP-P3), creating a novel formulation designed to enhance solubility, maintain bioactivity, and enable targeted delivery to tumour sites. Results: In an isogenic model of OAC radioresistance, AuNP-P3 significantly reduced the surviving fraction following irradiation, demonstrating its radiosensitizing properties. It also reduced mitochondrial metabolism and modulated the secretion of inflammatory mediators in both in vitro models of OAC radioresistance and human ex vivo OAC tumour explants. Furthermore, AuNP-P3 exhibited potent anti-angiogenic activity, significantly inhibiting blood vessel formation in vivo using zebrafish embryo models. Conclusions: These results collectively confirm that P3, in its conjugated formulation with gold nanoparticles, retains its therapeutic properties, highlighting the potential of AuNP-P3 as a novel therapeutic radiosensitizer for oesophageal adenocarcinoma and supporting its further development for clinical applications. Full article