Lenvatinib induces cardiac developmental toxicity in zebrafish embryos through regulation of Notch mediated-oxidative stress generation

Comparison of cardiotoxicity induced by alectinib, apatinib, lenvatinib and anlotinib in zebrafish embryos

Four tyrosine kinase inhibitors, alectinib, apatinib, lenvatinib and anlotinib, have been shown to be effective in the treatment of clinical tumors, but their cardiac risks have also raised concerns. In this study, zebrafish embryos at 6 h post fertilization (hpf) were exposed to the four drugs at concentrations of 0.05-0.2 mg/L until 72 hpf, and then the development of these embryos was quantified, including heart rate, body length, yolk sac area, pericardial area, distance between venous sinus and balloon arteriosus (SV-BA), separation of cardiac myocytes and endocardium, gene expression, vascular development and oxidative stress. At the same exposure concentrations, alectinib and apatinib had little effect on the cardiac development of zebrafish embryos, while lenvatinib and anlotinib could induce significant cardiotoxicity and developmental toxicity, including shortened of body length, delayed absorption of yolk sac, pericardial edema, prolonged SV-BA distance, separation of cardiomyocytes and endocardial cells, and downregulation of key genes for heart development. Heart rate decreased in all four drug treatment groups. In terms of vascular development, alectinib and apatinib did not inhibit the growth of embryonic intersegmental vessels (ISVs) and retinal vessels, while lenvatinib and anlotinib caused serious vascular toxicity, and the inhibition of anlotinib in vascular development was more obvious. Besides, the level of reactive oxygen species (ROS) in the lenvatinib and anlotinib treatment groups was significantly increased. Our results provide reference for comparing the cardiotoxicity of the four drugs.

Apatinib induces zebrafish hepatotoxicity by inhibiting Wnt signaling and accumulation of oxidative stress

Apatinib, a small-molecule VEGFR2-tyrosine kinase inhibitor, has shown potent anticancer activity in various clinical cancer treatments, but also different adverse reactions. Therefore, it is necessary to study its potential toxicity and working mechanism. We used zebrafish to investigate the effects of apatinib on the development of embryos. Zebrafish exposed to 2.5, 5, and 10 μM apatinib showed adverse effects such as decreased liver area, pericardial oedema, slow yolk absorption, bladder atrophy, and body length shortening. At the same time, it leads to abnormal liver tissue structure, liver function and related gene expression. Furthermore, after exposure to apatinib, oxidative stress levels were significantly elevated but liver developmental toxicity was effectively ameliorated with oxidative stress inhibitor treatment. Apatinib induces down-regulation of key target genes of Wnt signaling pathway in zebrafish, and it is found that Wnt activator can significantly rescue liver developmental defects. These results suggest that apatinib may induce zebrafish hepatotoxicity by inhibiting the Wnt signaling pathway and up-regulating oxidative stress, helping to strengthen our understanding of rational clinical application of apatinib.

Incorporating Primer Amplification Efficiencies in Quantitative Reverse Transcription Polymerase Chain Reaction Experiments; Considerations for Differential Gene Expression Analyses in Zebrafish

Quantitative reverse transcription polymerase chain reaction (RT-qPCR) is commonly used to measure the mRNA expression of target genes in zebrafish. Gene expression values from RT-qPCR are typically reported as relative fold-changes, and relative quantification of RT-qPCR data incorporates primer amplification efficiency values for each target gene. We describe the influence of the primer amplification efficiency analysis method on RT-qPCR gene expression fold-change calculations. This report describes (1) a sample analysis demonstrating incorporation of primer amplification efficiency into RT-qPCR analysis for comparing gene expression of a gene of interest between two groups when normalized to multiple reference genes, (2) the influence of differences in primer amplification efficiencies between measured genes on gene expression differences calculated from theoretical delta-Cq (dCq) values, and (3) an empirical comparison of the influence of three methods of defining primer amplification efficiency in gene expression analyses (delta-delta-Cq [ddCq], standard curve, LinRegPCR) using mRNA measurements of a set of genes in zebrafish embryonic development. Given the need to account for the influence of primer amplification efficiency along with the simplicity of using software programs (LinRegPCR) to measure primer amplification efficiency from RT-qPCR data, we encourage using empirical measurements of primer amplification efficiency for RT-qPCR analysis of differential gene expression in zebrafish.

Intergenerational toxic effects of parental exposure to [Cn mim]NO3 (n = 2,4,6) on nervous and skeletal development in zebrafish offspring

Ionic liquids (ILs) are thought to have negative effects on human health. Researchers have explored the effects of ILs on zebrafish development during the early stages, but the intergenerational toxicity of ILs on zebrafish development has rarely been reported. Herein, parental zebrafish were exposed to different concentrations (0, 12.5, 25, and 50 mg/L) of [Cn mim]NO3 (n = 2, 4, 6) for 1 week. Subsequently, the F1 offspring were cultured in clean water for 96 h. [Cn mim]NO3 (n = 2, 4, 6) exposure inhibited spermatogenesis and oogenesis in F0 adults, even causing obvious lacunae in the testis and atretic follicle oocytes in ovary. After parental exposure to [Cn mim]NO3 (n = 2, 4, 6), the body length and locomotor behavior were measured in F1 larvae at 96 hours post-fertilization (hpf). The results showed that the higher the concentration of [Cn mim]NO3 (n = 2, 4, 6), the shorter the body length and swimming distance, and the longer the immobility time. Besides, a longer alkyl chain length of [Cn mim]NO3 had a more negative effect on body length and locomotor behavior. RNA-seq analysis revealed several downregulated differentially expressed genes (DEGs)-grin1b, prss1, gria3a, and gria4a-enriched in neurodevelopment-related pathways, particularly the pathway for neuroactive ligand-receptor interaction. Moreover, several upregulated DEGs, namely col1a1a, col1a1b, and acta2, were mainly associated with skeletal development. Expression of DEGs was tested by RT-qPCR, and the outcomes were consistent with those obtained from RNA-Seq. We provide evidence showing the effects of parental exposure to ILs on the regulation of nervous and skeletal development in F1 offspring, demonstrating intergenerational effects.

Sphk1 deficiency induces apoptosis and developmental defects and premature death in zebrafish

The sphk1 gene plays a crucial role in cell growth and signal transduction. However, the developmental functions of the sphk1 gene during early vertebrate zebrafish embryo remain not completely understood. In this study, we constructed zebrafish sphk1 mutants through CRISPR/Cas9 to investigate its role in zebrafish embryonic development. Knockout of the sphk1 gene was found to cause abnormal development in zebrafish embryos, such as darkening and atrophy of the head, trunk deformities, pericardial edema, retarded yolk sac development, reduced heart rate, and premature death. The acetylcholinesterase activity was significantly increased after the knockout of sphk1, and some of the neurodevelopmental genes and neurotransmission system-related genes were expressed abnormally. The deletion of sphk1 led to abnormal expression of immune genes, as well as a significant decrease in the number of hematopoietic stem cells and neutrophils. The mRNA levels of cardiac development-related genes were significantly decreased. In addition, cell apoptosis increases in the sphk1 mutants, and the proliferation of head cells decreases. Therefore, our study has shown that the sphk1 is a key gene for zebrafish embryonic survival and regulation of organ development. It deepened our understanding of its physiological function. Our study lays the foundation for investigating the mechanism of the sphk1 gene in early zebrafish embryonic development.

Roxadustat induces hepatotoxicity in zebrafish embryos via inhibiting Notch signaling

Roxadustat is a novel and effective small-molecule inhibitor of hypoxia-inducible factor prolyl hydroxylase (HIF-PHI). However, little research has been done on its toxicity to vertebrate embryonic development. In this study, we used zebrafish to assess the effects of roxadustat on early embryonic development. Exposure to 14, 28, and 56 μM roxadustat resulted in abnormal embryonic development in zebrafish embryos, such as shortened body length and early liver developmental deficiency. Roxadustat exposure resulted in liver metabolic imbalance and abnormal liver tissue structure in adult zebrafish. In addition, roxadustat could up-regulate oxidative stress, and astaxanthin (AS) could partially rescue liver developmental defects by down-regulation of oxidative stress. After exposure to roxadustat, the Notch signaling is down-regulated, and the use of an activator of Notch signaling can partially rescue hepatotoxicity. Therefore, our research indicates that roxadustat may induce zebrafish hepatotoxicity by down-regulating Notch signaling. This study provides a reference for the clinical use of roxadustat.

Inhibition of YAP by lenvatinib in endothelial cells increases blood pressure through ferroptosis

Lenvatinib, a multitarget tyrosine kinase inhibitor (TKI), increases the incidence of severe hypertension and thus the incidence of cardiovascular complications. Inhibition of ferroptosis, a newly recognized type of cell death, alleviates endothelial dysfunction. Here, we report that lenvatinib-induced hypertension is associated with ferroptosis of endothelial cells. RNA sequencing (RNA-seq) showed that lenvatinib led to ferroptosis of endothelial cells and that administration of mouse with ferrostatin-1 (Fer-1), a specific ferroptosis inhibitor, dramatically ameliorated lenvatinib-induced hypertension and reversed lenvatinib-induced impairment of endothelium-dependent relaxation (EDR). Furthermore, lenvatinib significantly reduced glutathione peroxidase 4 (GPX4) expressions in the mouse aorta and human umbilical vein endothelial cells (HUVECs) and increased lipid peroxidation, lactate dehydrogenase (LDH) release, and malondialdehyde (MDA) levels in HUVECs. Immunofluorescence and Western blotting showed that lenvatinib significantly reduced Yes-associated protein (YAP) nuclear translocation but not cytoplasmic YAP expression in HUVECs. The data, generated from both in vivo and in vitro, showed that lenvatinib reduced total YAP (t-YAP) expression and increased the phosphorylation of YAP at both Ser127 and Ser397, without affecting YAP mRNA levels in HUVECs. XMU-MP-1 mediated YAP activation or YAP overexpression effectively attenuated the lenvatinib-induced decrease in GPX4 expression and increases in LDH release and MDA levels. In addition, overexpression of YAP in HUVECs ameliorated lenvatinib-induced decrease in the mRNA and protein levels of spermidine/spermine N (1)-acetyltransferase-1 (SAT1), heme oxygenase-1 (HO-1), and ferritin heavy chain 1 (FTH1). Taken together, our data suggest that lenvatinib-induced inhibition of YAP led to ferroptosis of endothelial cells and subsequently resulted in vascular dysfunction and hypertension.

Bromuconazole exposure induces cardiotoxicity and lipid transport disorder in larval zebrafish

Bromuconazole (BRO), as one of the typical triazole fungicides, has not been reported on its effects on aquatic organisms. In this study, zebrafish embryos were used as experimental objects to evaluate the toxicity of BRO. In the acute embryo toxicity test, it was observed that the heart rate and growing development were affected by BRO in a concentration-dependent manner, and the half-lethal concentration (LC50) of BRO at 96 h post-fertilization (hpf) was about 11.83 mg/L. Then, low concentrations of BRO (50 ng/L, 0.075 mg/L, 0.3 mg/L, 1.2 mg/L), which were set according to the LC50 and environmental related concentrations, were used to analyze the toxic effects on the different endpoints in larval zebrafish. Interestingly, the transcriptomic analysis found that most different expressed genes (DEGs) could be focused on the pathways of lipid metabolism, myocardial function, glycometabolism, indicating that heart function and lipid metabolism in larval zebrafish were disrupted by BRO. For supporting this idea, we re-exposed the transgenic zebrafish and WT zebrafish embryos, proved that BRO caused damage to heart development and lipid transport on morphological and genetic level, which was consistent with transcriptomic results. In addition, BRO exposure caused oxidative damage in the larvae. Taken together, BRO exposure could affect the myocardial contraction function and lipid transport in larval zebrafish, accompanied by disturbances in the level of oxidative stress, which was of great significance for improving the biotoxicological information of BRO.

Cysteamine affects skeletal development and impairs motor behavior in zebrafish

Cysteamine is a kind of feed additive commonly used in agricultural production. It is also the only targeted agent for the treatment of cystinosis, and there are some side effects in clinical applications. However, the potential skeletal toxicity remains to be further elucidated. In this study, a zebrafish model was for the first time utilized to synthetically appraise the skeletal developmental defects induced by cysteamine. The embryos were treated with 0.35, 0.70, and 1.05 mM cysteamine from 6 h post fertilization (hpf) to 72 hpf. Substantial skeletal alterations were manifested as shortened body length, chondropenia, and abnormal somite development. The results of spontaneous tail coiling at 24 hpf and locomotion at 120 hpf revealed that cysteamine decreased behavioral abilities. Moreover, the level of oxidative stress in the skeleton ascended after cysteamine exposure. Transcriptional examination showed that cysteamine upregulated the expression of osteoclast-related genes but did not affect osteoblast-related genes expression. Additionally, cysteamine exposure caused the downregulation of the Notch signaling and activating of Notch signaling partially attenuated skeletal defects. Collectively, our study suggests that cysteamine leads to skeletal developmental defects and reduces locomotion activity. This hazard may be associated with cysteamine-mediated inhibition of the Notch signaling and disorganization of notochordal cells due to oxidative stress and apoptosis.