Di-(2-ethylhexyl) phthalate impairs angiogenesis and hematopoiesis via suppressing VEGF signaling in zebrafish.

Di-(2-ethylhexyl) phthalate (DEHP) is among the most widely used plasticizers in plastic production, which has been detected in various environments. However, DEHP safety remains poorly known. Using zebrafish models, the effects of DEHP on the angiogenesis and hematopoiesis, and the underlying mechanism, were studied. Transgenic zebrafish embryos with specific fluorescence of vascular endothelial cells, myeloid cells, or hematopoietic stem cells were exposed to 0, 100, 150, 200, or 250 nM of DEHP for 22, 46 or 70 h, followed by fluorescence observation, endogenous alkaline phosphatase activity measurement, erythrocyte staining, and gene expression analysis by quantitative PCR and whole mount in situ hybridization. High DEHP concentrations decreased the sprouting rate, average diameter, and length, and the expansion area of the vessels lowered the EAP activity and suppressed the vascular endothelial growth factor (vegf) and hematopoietic marker genes, including c-myb, hbae1, hbbe1, and lyz expressions. DEHP treatment also decreased the number of hematopoietic stem cells, erythrocytes, and myeloid cells at 24 and 72 hpf. These DEHP-induced angiogenetic and hematopoietic defects might be alleviated by vegf overexpression. Our results reveal a plausible mechanistic link between DEHP exposure-induced embryonic angiogenetic defect and hematopoietic impairment.

Establishment of a lipid metabolism disorder model in ApoEb mutant zebrafish.

BACKGROUND AND AIMS: ApoEb is a zebrafish homologous to mammalian ApoE, whose deficiency would lead to lipid metabolism disorders (LMDs) like atherosclerosis. We attempted to knock out the zebrafish ApoEb, then establish a zebrafish model with LMD. METHODS: ApoEb was knocked out using the CRISPR/Cas9 system, and the accumulation of lipids was confirmed by Oil Red O staining, confocal imaging, and lipid measurements. The lipid-lowering effects of simvastatin (SIM), ezetimibe (EZE) and Xuezhikang (XZK), an extract derived from red yeast rice, were evaluated through in vivo imaging in zebrafish larvae. RESULTS: In the ApoEb mutant, significant vascular lipid deposition occurred, and lipid measurement performed in the whole-body homogenate of larvae and adult plasma showed significantly increased lipid levels. SIM, EZE and XZK apparently relieved hyperlipidemia in ApoEb mutants, and XZK had a significant inhibitory effect on the recruitment of neutrophils and macrophages. CONCLUSIONS: In this study, an LMD model has been established in ApoEb mutant zebrafish. We suggest that this versatile model could be applied in studying hypercholesterolemia and related vascular pathology in the context of early atherosclerosis, as well as the physiological function of ApoE.

Proangiogenesis effects of compound danshen dripping pills in zebrafish.

BACKGROUND: The compound Danshen Dripping Pill (CDDP), which is a mixture of extracts from Radix Salviae and Panax notoginseng, is a patented traditional Chinese medicine that is widely used in multiple countries for relieving coronary heart disease (CHD), but its pharmacological mechanism has not been fully elucidated. In this study, we screened the key pharmacological pathways and targets of CDDP that act on CHD using a network pharmacology-based strategy, and the angiogenic activity of CDDP was directly visually investigated in zebrafish embryos in vivo. METHODS: The potential therapeutic targets and pathways were predicted through a bioinformatics analysis. The proangiogenic effects of CDDP were examined using vascular sprouting assays on subintestinal vessels (SIVs) and optic arteries (OAs) as well as injury assays on intersegmental vessels (ISVs). Pharmacological experiments were applied to confirm the pathway involved. RESULTS: Sixty-five potential therapeutic targets of CDDP on CHD were identified and enriched in the PI3K/AKT and VEGF/VEGFR pathways. An in vivo study revealed that CDDP promoted angiogenesis in SIVs and OAs in a dose-dependent manner and relieved the impairments in ISVs induced by lenvatinib, a VEGF receptor kinase inhibitor (VRI). In addition, Vegfaa and Kdrl expression were significantly upregulated after CDDP treatment. Furthermore, the proangiogenic effect of CDDP could be abolished by PI3K/AKT pathway inhibitors. CONCLUSIONS: CDDP has a proangiogenic effect, the mechanism of which involves the VEGF/VEGFR and PI3K/AKT signaling pathways. These results suggest a new insight into the cardiovascular protective effect of CDDP.