Crucial role of zebrafish prox1 in hypothalamic catecholaminergic neurons development

<p>Abstract</p> <p>Background</p> <p><it>Prox1</it>, the vertebrate homolog of <it>prospero </it>in <it>Drosophila melanogaster</it>, is a divergent homeogene that regulates cell proliferation, fate determination and differentiation during vertebrate embryonic development.</p> <p>Results</p> <p>Here we report that, in zebrafish, <it>prox1 </it>is widely expressed in several districts of the Central Nervous System (CNS). Specifically, we evidenced <it>prox1 </it>expression in a group of neurons, already positive for <it>otp1</it>, located in the hypothalamus at the level of the posterior tuberculum (PT). Prox1 knock-down determines the severe loss of hypothalamic catecholaminergic (CA) neurons, identified by tyrosine hydroxylase (TH) expression, and the synergistic <it>prox1/otp1 </it>overexpression induces the appearance of hypothalamic supernumerary TH-positive neurons and ectopic TH-positive cells on the yolk epitelium.</p> <p>Conclusion</p> <p>Our findings indicate that <it>prox1 </it>activity is crucial for the proper development of the <it>otp1</it>-positive hypothalamic neuronal precursors to their terminal CA phenotype.</p

NRXN1 deletion and exposure to methylmercury increase astrocyte differentiation by different notch-dependent transcriptional mechanisms

Controversial evidence points to a possible involvement of methylmercury (MeHg) in the etiopathogenesis of autism spectrum disorders (ASD). In the present study, we used human neuroepithelial stem cells from healthy donors and from an autistic patient bearing a bi-allelic deletion in the gene encoding for NRXN1 to evaluate whether MeHg would induce cellular changes comparable to those seen in cells derived from the ASD patient. In healthy cells, a subcytotoxic concentration of MeHg enhanced astroglial differentiation similarly to what observed in the diseased cells (N1), as shown by the number of GFAP positive cells and immunofluorescence signal intensity. In both healthy MeHg-treated and N1 untreated cells, aberrations in Notch pathway activity seemed to play a critical role in promoting the differentiation toward glia. Accordingly, treatment with the established Notch inhibitor DAPT reversed the altered differentiation. Although our data are not conclusive since only one of the genes involved in ASD is considered, the results provide novel evidence suggesting that developmental exposure to MeHg, even at subcytotoxic concentrations, induces alterations in astroglial differentiation similar to those observed in ASD

Vandetanib versus cabozantinib in medullary thyroid carcinoma:A focus on anti‐angiogenic effects in zebrafish model

Medullary thyroid carcinoma (MTC) is a tumor deriving from the thyroid C cells. Vandetanib (VAN) and cabozantinib (CAB) are two tyrosine kinase inhibitors targeting REar-ranged during Transfection (RET) and other kinase receptors and are approved for the treatment of advanced MTC. We aim to compare the in vitro and in vivo anti‐tumor activity of VAN and CAB in MTC. The effects of VAN and CAB on viability, cell cycle, and apoptosis of TT and MZ‐CRC‐1 cells are evaluated in vitro using an MTT assay, DNA flow cytometry with propidium iodide, and An-nexin V‐FITC/propidium iodide staining, respectively. In vivo, the anti‐angiogenic potential of VAN and CAB is evaluated in Tg(fli1a:EGFP)y1 transgenic fluorescent zebrafish embryos by ana-lyzing the effects on the physiological development of the sub‐intestinal vein plexus and the tu-mor‐induced angiogenesis after TT and MZ‐CRC‐1 xenotransplantation. VAN and CAB exert comparable effects on TT and MZ‐CRC‐1 viability inhibition and cell cycle perturbation, and stimulated apoptosis with a prominent effect by VAN in MZ‐CRC‐1 and CAB in TT cells. Regard-ing zebrafish, both drugs inhibit angiogenesis in a dose‐dependent manner, in particular CAB shows a more potent anti‐angiogenic activity than VAN. To conclude, although VAN and CAB show comparable antiproliferative effects in MTC, the anti‐angiogenic activity of CAB appears to be more relevant.</p

Low in‑hospital mortality rate in patients with COVID‑19 receiving thromboprophylaxis: data from the multicentre observational START‑COVID Register

Abstract COVID-19 infection causes respiratory pathology with severe interstitial pneumonia and extra-pulmonary complications; in particular, it may predispose to thromboembolic disease. The current guidelines recommend the use of thromboprophylaxis in patients with COVID-19, however, the optimal heparin dosage treatment is not well-established. We conducted a multicentre, Italian, retrospective, observational study on COVID-19 patients admitted to ordinary wards, to describe clinical characteristic of patients at admission, bleeding and thrombotic events occurring during hospital stay. The strategies used for thromboprophylaxis and its role on patient outcome were, also, described. 1091 patients hospitalized were included in the START-COVID-19 Register. During hospital stay, 769 (70.7%) patients were treated with antithrombotic drugs: low molecular weight heparin (the great majority enoxaparin), fondaparinux, or unfractioned heparin. These patients were more frequently affected by comorbidities, such as hypertension, atrial fibrillation, previous thromboembolism, neurological disease,and cancer with respect to patients who did not receive thromboprophylaxis. During hospital stay, 1.2% patients had a major bleeding event. All patients were treated with antithrombotic drugs; 5.4%, had venous thromboembolism [30.5% deep vein thrombosis (DVT), 66.1% pulmonary embolism (PE), and 3.4% patients had DVT + PE]. In our cohort the mortality rate was 18.3%. Heparin use was independently associated with survival in patients aged ≥ 59 years at multivariable analysis. We confirmed the high mortality rate of COVID-19 in hospitalized patients in ordinary wards. Treatment with antithrombotic drugs is significantly associated with a reduction of mortality rates especially in patients older than 59 years

Global barn- och ungdomshälsa – Utmaningar och möjligheter

Global barn- och ungdomshälsa har förbättrats avsevärt under de senaste decennierna och står idag inför en mängd olika möjligheter och utmaningar i hög-, medel- och låginkomstländer. I denna artikeln beskriver vi några av de områden som är i fokus inom detta fält idag genom en kronologisk skildring i ljuset av de globala målen för hållbar utveckling samt diskuterar hur målen kan användas för att ge barn bättre förutsättningar i framtiden. Global child- and adolescence health has made tremendous advancements during recent decades, and is currently facing a diverse set of opportunities and challenges across high-, medium and low income countries. Using the Sustainable Development Goals as a roadmap, this article gives an overview of the main focuses of the field today and outlines the argument that child- and adolescence health must be prioritised. 

Crucial role of zebrafish in hypothalamic catecholaminergic neurons development-1

), dorsal view. Eyes or lens have been removed for better lateral viewing. () WISH combined with TH immunohistochemistry. Anti-TH antibody labels the PT and hypothalamic CA neurons at 36 hpf. Colabelling with is evident in a fraction of TH-positive neuroblasts in the hypothalamus (arrowheads), as also confirmed by the longitudinal section of the embryo (). microinjection of MO lowers the number of TH-labelled CA neurons in the hypothalamus in comparison to standard control injected embryos . coinjection of mRNA and MO rescued the morphant phenotype. () Quantitative real time RT-PCR. TH-specific mRNA is almost five-fold decreased following MO injection. The result represents at least three independent experiments, and 18S was used as an internal control. The following abbreviations are used: posterior tuberculum (PT), pituitary (Pit), hypothalamus (Hy), standard control morpholino oligonucleotide (stdr MO). Scale bars indicate 10 μm or 20 μm .<p><b>Copyright information:</b></p><p>Taken from "Crucial role of zebrafish in hypothalamic catecholaminergic neurons development"</p><p>http://www.biomedcentral.com/1471-213X/8/27</p><p>BMC Developmental Biology 2008;8():27-27.</p><p>Published online 10 Mar 2008</p><p>PMCID:PMC2288594.</p><p></p

Crucial role of zebrafish in hypothalamic catecholaminergic neurons development-3

Ls in control and overexpressed /embryos at 36 hpf. The most numerous class in the group of GFP mRNA injected control embryos presented 8 CA hypothalamic neurons, and only 3 embryos presented more than 11 TH hypothalamic positive cells (n = 54). The most numerous class in the group of the overexpressed /embryos (n = 64) presented 10 CA neurons, and 20 embryos showed more than 11 TH hypothalamic positive cells. Immunostaining with TH antibody shows ectopic TH positive cells on the yolk surface ectoderm of double injected embryos (arrowheads), while these cells are not present on the yolk of control embryos. Ectopic TH positive cell on the yolk surface ectoderm. Scale bars indicate 50 μm.<p><b>Copyright information:</b></p><p>Taken from "Crucial role of zebrafish in hypothalamic catecholaminergic neurons development"</p><p>http://www.biomedcentral.com/1471-213X/8/27</p><p>BMC Developmental Biology 2008;8():27-27.</p><p>Published online 10 Mar 2008</p><p>PMCID:PMC2288594.</p><p></p

Crucial role of zebrafish in hypothalamic catecholaminergic neurons development-4

Epiboly (lane 2), 50% epiboly (lane 3), 80% epiboly (lane 4), tail bud (lane 5), 8 somites (lane 6), 15 somites (lane 7), 24 hpf (lane 8), 72 hpf (lane 9), 5 dpf (lane 10) and negative control (lane 11) in the absence of cDNA. ) RT-PCR performed on different adult organs: DNA ladder (L), testis (lane 1), overy (lane 2), gills (lane 3), gut (lane 4), eye (lane 5), brain (lane 6) and liver (lane 7). Arrowhead indicates the size of the -specific PCR product (620 bp). WISH the first signals appeared at 2 s in the otic placode (arrowhead). at 15 s the signal is detected in the lens placode (arrowhead), and somites (inset). at 24 hpf is expressed the hypothalamus (asterisc), the pituitary (black arrowhead), the pretectal segment (prosomere 1) (white arrow), as well as segmentally arranged cells of the hindbrain (black arrow). transverse section through the forebrain of a 24 hpf stage zebrafish embryo shows the signal in the lens (black arrowhead). at 24 hpf additional signals are present in the liver primordium (arrow), and posterior lateral line primordium (arrowheads). later during development, (48 hpf) expression is detected in distinct domains in the liver (arrow) and pancreas (arrowhead), while a further signal appeares in the retina (white arrow). transverse section through the forebrain of a 7 dpf stage zebrafish larva shows the signals in the retina inner nuclear layer (arrow) and in the pretectal nuclei (arrowhead). Lateral views are shown. Frontal view is shown. Dorsal views are shown. Anterior is always to the left. Scale bars indicate 100 μm () or 200 μm ().<p><b>Copyright information:</b></p><p>Taken from "Crucial role of zebrafish in hypothalamic catecholaminergic neurons development"</p><p>http://www.biomedcentral.com/1471-213X/8/27</p><p>BMC Developmental Biology 2008;8():27-27.</p><p>Published online 10 Mar 2008</p><p>PMCID:PMC2288594.</p><p></p

Crucial role of zebrafish in hypothalamic catecholaminergic neurons development-0

Epiboly (lane 2), 50% epiboly (lane 3), 80% epiboly (lane 4), tail bud (lane 5), 8 somites (lane 6), 15 somites (lane 7), 24 hpf (lane 8), 72 hpf (lane 9), 5 dpf (lane 10) and negative control (lane 11) in the absence of cDNA. ) RT-PCR performed on different adult organs: DNA ladder (L), testis (lane 1), overy (lane 2), gills (lane 3), gut (lane 4), eye (lane 5), brain (lane 6) and liver (lane 7). Arrowhead indicates the size of the -specific PCR product (620 bp). WISH the first signals appeared at 2 s in the otic placode (arrowhead). at 15 s the signal is detected in the lens placode (arrowhead), and somites (inset). at 24 hpf is expressed the hypothalamus (asterisc), the pituitary (black arrowhead), the pretectal segment (prosomere 1) (white arrow), as well as segmentally arranged cells of the hindbrain (black arrow). transverse section through the forebrain of a 24 hpf stage zebrafish embryo shows the signal in the lens (black arrowhead). at 24 hpf additional signals are present in the liver primordium (arrow), and posterior lateral line primordium (arrowheads). later during development, (48 hpf) expression is detected in distinct domains in the liver (arrow) and pancreas (arrowhead), while a further signal appeares in the retina (white arrow). transverse section through the forebrain of a 7 dpf stage zebrafish larva shows the signals in the retina inner nuclear layer (arrow) and in the pretectal nuclei (arrowhead). Lateral views are shown. Frontal view is shown. Dorsal views are shown. Anterior is always to the left. Scale bars indicate 100 μm () or 200 μm ().<p><b>Copyright information:</b></p><p>Taken from "Crucial role of zebrafish in hypothalamic catecholaminergic neurons development"</p><p>http://www.biomedcentral.com/1471-213X/8/27</p><p>BMC Developmental Biology 2008;8():27-27.</p><p>Published online 10 Mar 2008</p><p>PMCID:PMC2288594.</p><p></p