Therapeutic Effects of Iron Chelation in Atorvastatin-Induced Intracranial Hemorrhage of Zebrafish Larvae.

OBJECTIVE: Intracranial hemorrhage (ICH) catastrophically damages the cerebral vasculature, and severely compromises blood-brain barrier (BBB) function. The prognosis of ICH is poor due to the drastic and rapid progression of its pathology, and the lack of effective treatments presents a significant unmet clinical need. The present paper provides several evidences about the relationship between ICH bleeding status and mortality and the potential therapeutic effects of an iron chelator for ICH. METHODS: Zebrafish are a highly transparent animal model, allowing live imaging of the complex cerebral vasculature. Thus, to further elucidate ATV-induced ICH, we investigated the concentration- and time-dependent phenotypes of ATV-induced ICH with zebrafish larvae. RESULTS: The effects of ATV on mortality and ICH incidence in zebrafish larvae were concentration-dependent. Further, ATV treatment decreased vascular density of the hindbrain in a concentration-dependent manner, and hematoma volume was inversely correlated with ATV concentration. The number of cranial TUNEL-positive apoptotic cells was markedly increased 3 days post-fertilization. Importantly, the iron chelator deferasirox (DFR) decreased the incidence of ATV-induced ICH in zebrafish larvae. CONCLUSION: These findings provided insight into the pathology and regulatory mechanism of ATV-induced ICH, and demonstrated the therapeutic effects of iron chelators.

CCDC134 serves a crucial role in embryonic development.

Coiled-coil domain containing 134 (CCDC134), a characterized secreted protein, may serve as an immune cytokine and illustrates its potent antitumor effects by augmenting CD8+ T-cell-mediated immunity. Additionally, CCDC134 may also act as a novel regulator of human alteration/deficiency in activation 2a, and be involved in the p300-CBP-associated factor complex and affect its acetyltransferase activity. To clarify the biological and pathological function of CCDC134, the present study generated a viable and fertile Ccdc134fl/fl mouse strain that allowed temporal and spatial control of gene ablation. Ccdc134-/- embryos generated by crossing of Ccdc134fl/fl mice with human ß-actin-Cre or zona pellucida 3-Cre transgenic mice were embryonic lethal from embryonic day (E)12.5 to birth. Ccdc134 loss was associated with severe hemorrhages in the brain ventricular space and neural tube, pale and abnormal livers, cardiac hypertrophy and placental distress. Furthermore, it was demonstrated that a fraction of E13.5 fetal livers and brains exhibited reduced cell proliferation and vascular endothelial cell defects. CCDC134 also exhibited a dynamic and specific expression pattern during embryo development. The present results suggest that Ccdc134 may have specific biological functions in regulating mouse embryonic development.

Maternal anti-platelet ß3 integrins impair angiogenesis and cause intracranial hemorrhage.

Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is a life-threatening disease in which intracranial hemorrhage (ICH) is the major risk. Although thrombocytopenia, which is caused by maternal antibodies against ß3 integrin and occasionally by maternal antibodies against other platelet antigens, such as glycoprotein GPIbα, has long been assumed to be the cause of bleeding, the mechanism of ICH has not been adequately explored. Utilizing murine models of FNAIT and a high-frequency ultrasound imaging system, we found that ICH only occurred in fetuses and neonates with anti-ß3 integrin-mediated, but not anti-GPIbα-mediated, FNAIT, despite similar thrombocytopenia in both groups. Only anti-ß3 integrin-mediated FNAIT reduced brain and retina vessel density, impaired angiogenic signaling, and increased endothelial cell apoptosis, all of which were abrogated by maternal administration of intravenous immunoglobulin (IVIG). ICH and impairment of retinal angiogenesis were further reproduced in neonates by injection of anti-ß3 integrin, but not anti-GPIbα antisera. Utilizing cultured human endothelial cells, we found that cell proliferation, network formation, and AKT phosphorylation were inhibited only by murine anti-ß3 integrin antisera and human anti-HPA-1a IgG purified from mothers with FNAIT children. Our data suggest that fetal hemostasis is distinct and that impairment of angiogenesis rather than thrombocytopenia likely causes FNAIT-associated ICH. Additionally, our results indicate that maternal IVIG therapy can effectively prevent this devastating disorder.

Characterization of samhd1 morphant zebrafish recapitulates features of the human type I interferonopathy Aicardi-Goutières syndrome.

In humans, loss of function mutations in the SAMHD1 (AGS5) gene cause a severe form of Aicardi-Goutières syndrome (AGS), an inherited inflammatory-mediated encephalopathy characterized by increased type I IFN activity and upregulation of IFN-stimulated genes (ISGs). In particular, SAMHD1-related AGS is associated with a distinctive cerebrovascular pathology that commonly leads to stroke. Although inflammatory responses are observed in immune cells cultured from Samhd1 null mouse models, these mice are physically healthy, specifically lacking a brain phenotype. We have investigated the use of zebrafish as an alternative system for generating a clinically relevant model of SAMHD1-related AGS. Using temporal gene knockdown of zebrafish samhd1, we observe hindbrain ventricular swelling and brain hemorrhage. Furthermore, loss of samhd1 or of another AGS-associated gene, adar, leads to a significant upregulation of innate immune-related genes and an increase in the number of cells expressing the zebrafish type I IFN ifnphi1. To our knowledge, this is the first example of an in vivo model of AGS that recapitulates features of both the innate immune and neurological characteristics of the disease. The phenotypes associated with loss of samhd1 and adar suggest a function of these genes in controlling innate immune processes conserved to zebrafish, thereby also contributing to our understanding of antiviral signaling in this model organism.

Cerebral ischemia or intrauterine inflammation promotes differentiation of oligodendroglial precursors in preterm ovine fetuses: possible cellular basis for white matter injury.

White matter injury in premature infants is known to be major cause of long-term neurocognitive disability, but the pathogenic mechanism remains unclear, hampering our ability to develop preventions. Periventricular leukomalacia is a severe form of white matter injury. In the present study, we explored the effects of cerebral ischemia and/or intrauterine inflammation on the development of oligodendroglia in the cerebral white matter using chronically instrumented fetal sheep. Each fetus received one of three insults: hemorrhage, inflammation and their combination. In the hemorrhage group, 40% of the fetoplacental blood volume was acutely withdrawn, and 24 hours after removal, the blood was returned to the fetus. The inflammation group received intravenous granulocyte-colony stimulating factor and intra-amniotic endotoxin and thus suffered from necrotizing funisitis and chorioamnionitis. The inflammatory hemorrhage group underwent acute hemorrhage under the inflammatory state. The sham group received no insults. Importantly, periventricular leukomalacia was not detected in the sham and the inflammation groups. Differentiating oligodendroglia at various developmental stages were identified by immunohistochemical analysis with specific antibodies. No difference in the density of oligodendroglial progenitors was detected among the four groups, whereas oligodendroglial precursors were significantly reduced in the three insult groups, compared to sham control. Moreover, the density of immature oligodendroglia was higher in the inflammation group and the inflammatory hemorrhage group, while the density of mature oligodendroglia was highest in the hemorrhage group. We propose that cerebral ischemia or intrauterine inflammation induces the differentiation of oligodendroglial precursors in preterm fetuses, eventually resulting in their exhaustion.

What is the clinical importance of echogenic material in the fetal frontal horns?

OBJECTIVE: The purpose of this study was to evaluate the importance of echogenic material in the fetal frontal horns. METHODS: This was a Health Insurance Portability and Accountability Act-compliant, Institutional Review Board-approved retrospective study. In part 1 of the study, prenatal sonography, prenatal magnetic resonance imaging (MRI), and birth outcomes of 17 fetuses (mean gestational age, 19 weeks; range, 15-34 weeks) with prospective echogenic material in the frontal horns were assessed. In part 2, 400 consecutive sonographic fetal surveys (mean gestational age, 19 weeks; range, 15-38 weeks) were reviewed to determine the incidence. In part 3, 2 independent reviewers assessed the appearance of the frontal horns in 40 fetuses (20 with suspected intraventricular hemorrhage from parts 1 and 2 and 20 who were interpreted to have normal findings in part 2). RESULTS: Part 1 of the study showed that suspected hemorrhage was unilateral in 13 fetuses and bilateral in 4. Additional findings by sonography were grade 4 intraventricular hemorrhage (n = 2), ventriculomegaly (n = 2), and porencephaly (n = 1). An additional finding by MRI was porencephaly in 1 fetus. In part 2, echogenic material in the frontal horns was identified in 3 of 400 fetuses (0.8%). In part 3, hemorrhage was probably or definitely present in 11 of the 20 fetuses with abnormalities; material looked like a cyst in 6; and normal choroid was in an abnormal position in 2 and a normal position 1. Of 19 fetuses with abnormalities, 14 had a posteriorly symmetric choroid; 9 had material of different echogenicity compared with the choroid; and 17 had an expanded frontal horn. Birth outcomes were abnormal in 7, including platelet abnormalities (n = 2), hemorrhage on imaging or pathologic examination (n = 2), extraventricular hemorrhage (n = 3), and ventriculomegaly (n = 3). CONCLUSIONS: The incidence of echogenic material in the frontal horns is less than 1%. This does not represent the normal location of the choroid plexus and may represent hemorrhage, which may resolve without sequelae or result in ventriculomegaly and porencephaly.

Prenatal diagnosis of cerebral lesions acquired in utero and with a late appearance.

Although no precise figures are available, many congenital brain lesions arise from intrauterine disruption, frequently due to obstetric complications. The most common entities include intracranial hemorrhage, ischemic lesions, thrombosis of venous vessels and infections. Accurate prenatal diagnosis is possible in many of these cases. However, the findings may be subtle, particularly in the early stage of the disruptive process. Identification of these conditions requires therefore specific expertise, the combination of fetal neurosonography and magnetic resonance, and frequently there is a need for serial examinations. Targeted diagnostic imaging should be offered to obstetric patients with conditions predisposing to prenatal cerebral insults.

Pathology of goose haemorrhagic polyomavirus infection in goose embryos.

Goose embryos were infected with goose haemorrhagic polyomavirus (GHPV) onto the chorioallantoic membrane (CAM) in order to examine the effect of GHPV on the embryos and to obtain data on whether embryos could develop into infected, virus-shedding goslings, as well as to present an accurate biological method for virus titration. The reported method of infection could offer a possibility to express the virus titre as the median embryo infective dose (EID(50)). As a special pathological feature of the disease, extensive cerebral haemorrhages were observed, which protruded the skullcap in many cases. Some embryos infected with 10(1.25) or 10(0.25) EID(50)/0.2 ml were able to hatch; however, they were in poor physical condition and died by post-hatching day 4 showing haemorrhagic nephritis and enteritis of geese. Virus shedding was revealed by polymerase chain reaction. The ability of some of the infected goose embryos to hatch may indicate the potency of GHPV to spread vertically, although this needs further study for confirmation.

DNA damage, histological changes and DNA repair in larval Japanese medaka (Oryzias latipes) exposed to ultraviolet-B radiation.

Cyclobutane dimer formation, photorepair capability and histological damage were compared among four differently pigmented strains of larval Japanese medaka (Oryzias latipes) to determine whether pigmentation modifies the level of UV-B radiation (290-320 nm) inducible damage in these fish. One-day post-hatch medaka were exposed to one of several UV-B fluence rates with or without photoreactivating light for 5 days for 7 h per day. Their DNA was extracted for analysis by ELISA for cyclobutane pyrimidine dimers or the larvae were processed for histological examination. At the higher UV-B fluence rates tested, wild-type melanophore-containing medaka formed significantly more dimers than at least one of the other strains tested. Wild-type medaka also showed significantly less photorepair capability than the white melanophore-lacking medaka. The wild-type larvae had significantly more necrosis than the orange-red melanophore-lacking larvae at the lower UV-B fluence rate tested and at the higher fluence rate used, the wild-type medaka also exhibited significantly more necrosis than the white melanophore-lacking larvae. Of the 19 medaka observed with cellular hyperplasia, six were wild-type. These six individual larvae showed the greatest degree of cellular hyperplasia. Cellular hyperplasia appeared to be greatest at the lowest UV-B fluence rate used. The presence of melanophores in the wild-type medaka may have contributed to an increased level of tissue damage in this strain when compared to the other strains.