Search

Narcissin is a natural flavonoid from some edible and traditional medicinal plants. It has been proven to have multiple biological functions and exhibits potential therapeutic effects on hypertension, cancer, and Alzheimer's disease. However, the toxicity of narcissin is largely unknown. Here, we revealed that narcissin treatment led to reduced hatchability, increased malformation rate, shorter body length, and slowed blood flow in zebrafish. Furthermore, bradycardia, pericardial edema, increased SV-BA distance, diminished stroke volume, ejection fraction, and ventricular short-axis shortening rate were also found. A large accumulation of ROS, increased apoptotic cells, and histopathological changes were detected in the heart region. Moreover, the gene expression profiles and molecular docking analysis indicated that Nrf2/HO-1 and calcium signaling pathways were involved in narcissin-induced toxicity. In conclusion, here we provide the first evidence that demonstrates narcissin-induced developmental toxicity and cardiotoxicity in zebrafish via Nrf2/HO-1 and calcium signaling pathways for the first time., (© 2023 John Wiley & Sons, Ltd.)

A new prenylated indole alkaloid-Penicimutamide C N -oxide ( 1 ), a new alkaloid penicimutamine A ( 2 ), along with six known alkaloids were isolated from an endophytic fungus Pallidocercospora crystallina . A simple and accurate method was used to determine the N-O bond in the N -oxide group of 1 . By using a β-cell ablation diabetic zebrafish model, compounds 1 , 3 , 5 , 6 and 8 showed significantly hypoglycemic activities under the concentration of 10 μM. Further studies revealed that compounds 1 and 8 lowered the glucose level through promoting glucose uptake in zebrafish. In addition, all eight compounds showed no acute toxicity, teratogenicity, nor vascular toxicity in zebrafish under the concentrations range from 2.5 μΜ to 40 μM. Importantly, these results provide new lead compounds for the development of antidiabetes strategies.

Zebrafish irf2bp2a, an ortholog of human IRF2BP2, is specifically expressed in the developing liver at growth stage. As a multi-functional protein, the role of irf2bp2a during hepatogenesis remains unclear. Here we take advantage of an irf2bp2a knockout line to show that the deficiency of irf2bp2a can induce apoptosis of hepatic cells through aberrant p53 activation at the early stage of embryonic development. Mechanistic studies reveal that within the IRF2BP2-null hepatic cells, more MDM2 molecules, the E3 ubiquitin ligase of P53, can be sequestrated into the IRF2-MDM2 complex, which in turns stabilizes P53 protein. Moreover, irf2bp2a is demonstrated as a direct downstream target of c/ebpα. Thus, a C/ebpα-Irf2bp2a-P53 axis controls liver development in zebrafish. Overall, our findings indicate a stage-specific role of irf2bp2a on liver organogenesis by regulating p53 pathway., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Toosendanin (TSN) is a crucial component from Toosendan Fructus with a promising anti-tumor capacity. It is also the primary suspect hepatotoxic component of Toosendan Fructus. However, the mechanisms underlying TSN-induced liver injury are still largely unknown. In present study, we evaluated the hepatotoxicity of TSN on zebrafish and explored the role of inflammation, autophagy, and apoptosis in TSN-induced hepatotoxicity. We found that TSN treatment decreased the area and fluorescence intensity of zebrafish liver in time- and dose-dependent manners at nonlethal concentrations. The ALT and AST activities were increased after TSN treatment. Severe cytoplasmic vacuolation and nuclear shrank were found in the liver of TSN-treated zebrafish. The expression profile of genes demonstrated that inflammation, autophagy and apoptosis pathways were involved in TSN-induced hepatotoxicity. Our study demonstrated for the first time that TSN treatment gave rise to liver injury in zebrafish, and inflammation, autophagy, apoptosis played a role in TSN-induced hepatotoxicity., (Copyright © 2021. Published by Elsevier Inc.)

The ubiquitin-proteasome system plays important roles in various biological processes as it degrades the majority of cellular proteins. Adequate proteasomal degradation of crucial transcription regulators ensures the proper development of neutrophils. The ubiquitin E3 ligase of Growth factor independent 1 (GFI1), a key transcription repressor governing terminal granulopoiesis, remains obscure. Here we report that the deficiency of the ring finger protein Interferon regulatory factor 2 binding protein 2a (Irf2bp2a) leads to an impairment of neutrophils differentiation in zebrafish. Mechanistically, Irf2bp2a functions as a ubiquitin E3 ligase targeting Gfi1aa for proteasomal degradation. Moreover, irf2bp2a gene is repressed by Gfi1aa, thus forming a negative feedback loop between Irf2bp2a and Gfi1aa during neutrophils maturation. Different levels of GFI1 may turn it into a tumor suppressor or an oncogene in malignant myelopoiesis. Therefore, discovery of certain drug targets GFI1 for proteasomal degradation by IRF2BP2 might be an effective anti-cancer strategy., Competing Interests: The authors have declared that no competing interests exist.

Aproper choice of neutrophil-macrophage progenitor cell fate is essential for the generation of adequate myeloid subpopulations during embryonic development and in adulthood. The network governing neutrophil-macrophage progenitor cell fate has several key determinants, such as myeloid master regulators CCAAT enhancer binding protein alpha (C/EBPα) and spleen focus forming virus proviral integration oncogene (PU.1). Nevertheless, more regulators remain to be identified and characterized. To ensure balanced commitment of neutrophil-macrophage progenitors toward each lineage, the interplay among these determinants is not only synergistic, but also antagonistic. Depletion of interferon regulatory factor 2 binding protein 2b (Irf2bp2b), a well-known negative transcription regulator, results in a bias in neutrophil-macrophage progenitor cell fate in favor of macrophages at the expense of neutrophils during the stage of definitive myelopoiesis in zebrafish embryos. Mechanistic studies indicate that Irf2bp2b acts as a downstream target of C/EBPα, repressing PU.1 expression, and that SUMOylation confers the repressive function of Irf2bp2b. Thus, Irf2bp2b is a novel determinant in the choice of fate of neutrophil-macrophage progenitor cells., (Copyright© 2020 Ferrata Storti Foundation.)

Aconitine (AC), one of the bioactive diterpenoid alkaloids extracted from Aconitum plants, is widely used in traditional herbal medicine to treat various diseases. Emerging evidence indicates that AC has attracted great interest for its wide cardiotoxicity and neurotoxicity. However, the toxic effects of AC on embryonic development and its underlying mechanisms remain unclear. Here, a developmental toxicity assay of AC was performed on zebrafish embryos from 4 to 96 h post fertilization (hpf), and its underlying mechanisms were discussed. AC exposure impaired the cardiac, liver, and neurodevelopment. Especially, a high dose of AC (7.27 and 8.23 μM) exposure resulted in malformations at 72 and 96 hpf, including reduced body length, curved body shape, pericardial edema, yolk retention, swim bladder and brain developmental deficiency, and degeneration of dopaminergic neurons. High-concentration AC exposure caused a deficient cardiovascular system with cardiac dysfunctions, increased heart rates at 72 and 96 hpf, and reduced locomotor behavior at 120 hpf. AC treatment significantly increased the ROS level and triggered cell apoptosis in the heart and brain regions of embryos at 96 hpf in 7.27 and 8.23 μM AC treatment zebrafish. Oxidative stress was confirmed by reduced levels of T-SOD activity associated with accumulation of lipid peroxidation in larvae. The expression levels of oxidative stress-related genes (Nrf2 , HO-1 , Cat , and Sod-1) Erk1/2 and Bcl-2 were significantly downregulated at 96 hpf. The expression pattern of JNK and mitochondrial apoptosis-related genes (Bad , Bax , Cyto C , Casp-9 , and Casp-3) was significantly upregulated. Taken together, all these parameters collectively provide the first evidence of AC-induced developmental toxicity in zebrafish embryo/larvae through ROS-medicated mitochondrial apoptosis involving Nrf2/HO-1 and JNK/Erk pathways. [ABSTRACT FROM AUTHOR]