Interaction of transcription factors Islet2 and Nr2f1b to control vascular patterning during zebrafish development.

Many regulators controlling arterial identity are well described; however, transcription factors that promote vein identity and vascular patterning have remained largely unknown. We previously identified the transcription factors Islet2 (Isl2) and Nr2f1b required for specification of the vein and tip cell identity mediated by notch pathway in zebrafish. However, the interaction between Isl2 and Nr2f1b is not known. In this study, we report that Nr2f2 plays minor roles on vein and intersegmental vessels (ISV) growth and dissect the genetic interactions among the three transcription factors Isl2, Nr2f1b, and Nr2f2 using a combinatorial knockdown strategy. The double knockdown of isl2/nr2f1b, isl2/nr2f2, and nr2f1b/nr2f2 showed the enhanced defects in vasculature including less completed ISV, reduced veins, and ISV cells. We further tested the genetic relationship among these three transcription factors. We found isl2 can regulate the expression of nr2f1b and nr2f2, suggesting a model where Isl2 functions upstream of Nr2f1b and Nr2f2. We hypothsized that Isl2 and Nr2f1b can function together through cis-regulatory binding motifs. In-vitro luciferase assay results, we showed that Isl2 and Nr2f1b can cooperatively enhance gene expression. Moreover, co-immunoprecipitation results indicated that Isl2 and Nr2f1b interact physically. Together, we showed that the interaction of the Nr2f1b and Nr2f2 transcription factors in combination with the Islet2 play coordinated roles in the vascular development of zebrafish.

Coral-Derived Natural Marine Compound GB9 Impairs Vascular Development in Zebrafish.

Blood vessels in vertebrates are established and genetically controlled in an evolutionarily-conserved manner during embryogenesis. Disruption of vascular growth by chemical compounds or environmental hormones may cause developmental defects. This study analyzed the vascular impacts of marine compound GB9 in zebrafish. GB9 was isolated from the marine soft coral Capnella imbricata and had shown anti-neuroinflammatory and anti-nociceptive activities. However, the role of GB9 on vascular development has not been reported. We first tested the survival rate of embryos under exogenous 5, 7.5, 10, and 15 µM GB9 added to the medium and determined a sub-lethal dosage of 10 µM GB9 for further assay. Using transgenic Tg(fli:eGFP) fish to examine vascular development, we found that GB9 treatment impaired intersegmental vessel (ISV) growth and caudal vein plexus (CVP) patterning at 25 hours post-fertilization (hpf) and 30 hpf. GB9 exposure caused pericardial edema and impaired circulation at 48-52 hpf, which are common secondary effects of vascular defects and suggest the effects of GB9 on vascular development. Apoptic cell death analysis showed that vascular defects were not caused by cell death, but were likely due to the inhibition of migration and/or proliferation by examining ISV cell numbers. To test the molecular mechanisms of vascular defects in GB9-treated embryos, we examined the expression of vascular markers and found the decreased expression of vascular specific markers ephrinb2, flk, mrc1, and stabilin. In addition, we examined whether GB9 treatment impairs vascular growth due to an imbalance of redox homeostasis. We found an enhanced effect of vascular defects during GB9 and H2O2 co-treatment. Moreover, exogenous N-acetyl-cysteine (NAC) treatment rescued the vascular defects in GB9 treated embryos. Our results showed that GB9 exposure causes vascular defects likely mediated by the imbalance of redox homeostasis.

In vivo monitoring of carbonic anhydrase expression during the growth of larval zebrafish: a new environment-sensitive fluorophore for responsive turn-on fluorescence.

This study monitors the dynamic progress of a newly developed background-free, target responsive strategy; 2,3-dihydroquinolin-4-imine (DQI) that can instantly respond to environmental changes with fluorescence enhancement, revealing a comprehensive platform for in vivo fluorescence bioimaging of mebrane-bound carbonic anhydrase II in HeLa cells and its expression during the growth of larval zebrafish.

Association of serum cystatin C levels with mortality in patients with acute type A aortic dissection.

Increased serum cystatin C levels are related to the prognosis of cardiovascular diseases. This study aims to investigate the effect of admission serum cystatin C levels on short- and long-term mortality in patients with acute type A aortic dissection (ATAAD). From 2010 to 2014, 136 consecutive patients with ATAAD were enrolled and followed up. Clinical data and laboratory assays including were measured. During a median follow-up of 198.7 days, the short-term mortality (30-days) was 20.6%, whereas the long-term death rate was 10.2%. We identified that the expression of cystatin C and high-sensitivity C-reactive protein (hs-CRP) in the dying patients was higher than in the surviving patients (P < 0.01). Hs-CRP (HR = 1.41, 95% CI: 1.03-2.59, P = 0.037) was an independent risk factor of short-term death determined by univariate and multivariate Cox analyses. No impact of cystatin C was observed on the short-term mortality. For long-term mortality, cystatin C (HR = 1.49, 95% CI: 1.10-7.36, P = 0.013) was identified as an independent predictor at above the cut-off value ≥ 1.10 mg/L. ROC analysis showed the AUC values of cystatin C and hs-CRP were 0.772 (95% CI, 0.692-0.839) and 0.640 (95% CI, 0.574-0.739), respectively, in the prediction of long-term death. The combined AUC value of cystatin C and hs-CRP was 0.883 (95% CI, 0.826-0.935; P < 0.01). Taken together, high cystatin C levels (≥ 1.10 mg/L) on admission are independently associated with the long-term mortality in patients with ATAAD.

Self-expandable valved stent of large size: off-bypass implantation in pulmonary position.

OBJECTIVE: To evaluate the feasibility of the off-bypass implantation of a self-expandable valved stent of large size in pulmonary position. MATERIALS AND METHODS: A glutaraldehyde preserved valved bovine jugular xenograft with internal diameter = 22 mm, mounted in two rings of nitinol 'Z' stent, expandable from 7 to 24 mm of internal diameter, was acutely evaluated in 6 adult pigs, mean body weight 55.6 kg (range 47-67 kg). Through a stent-graft delivery system (24 French) the self expandable valved stent was implanted off-bypass in pulmonary valve position by trans-ventricular approach through median sternotomy. RESULTS: The mean diameter of the main pulmonary artery measured was 21.7 +/- 1.6 mm. The mean length of the self expandable valved stent was 23.1 +/- 0.7 mm, the mean internal diameter 21.6 +/- 0.7 mm and the mean external diameter 26.3 +/- 0.7 mm. The mean peak pressure gradient recorded across the valve was 6.33 +/- 2.8 mmHg (range 4.5-9.6 mmHg) at Doppler echocardiography, and 4.5 +/- 3.1 mmHg (range 0-7 mmHg) at invasive measurement, with a pulmonary blood flow of 3.03 +/- 0.05 l/min. Intra-vascular ultrasound showed complete opening and closure of the valve (mean area reduction from 315.08 +/- 54.13 to 0 mm2). CONCLUSIONS: (a) Off-bypass implantation of self-expandable valved stent is feasible in pulmonary position; (b) off-bypass surgical approach allows for valved stent implantation of adult size with adequate hemodynamic functioning; and (c) intra-vascular ultrasound makes implantation and evaluation easy and reproducible.