Protein transport between the trans-Golgi network and endosomes is mediated by transport vesicles formed by the adaptor-protein complex AP-1, consisting of the adaptins g1, b1, m1, s1. Mammalia express m1A ubiquitously and isoform m1B in polarized epithelia. Mouse g1 or m1A 'knock out's revealed that AP-1 is indispensable for embryonic development. We isolated m1A and m1B from Danio rerio. Analysis of m1A and m1B expression revealed tissue-specific expression for either one during embryogenesis and in adult tissues in contrast to their expression in mammalia. m1B transcript was detected in organs of endodermal derivation and ''knock-down'' experiments gave rise to embryos defective in formation of intestine, liver, and pronephric ducts. Development ceased at 7-8 dpf. m1B is not expressed in murine liver, indicating loss of m1B expression and establishment of alternative sorting mechanisms during mammalian development. Developmental Dynamics 239:2404-2412,
The lysosomal hydrolase galactocerebrosidase (GALC) catalyzes the removal of galactose from galactosylceramide and from other sphingolipids. GALC deficiency is responsible for globoid cell leukodystrophy (GLD), or Krabbe's disease, an early lethal inherited neurodegenerative disorder characterized by the accumulation of the neurotoxic metabolite psychosine in the central nervous system (CNS). The poor outcome of current clinical treatments calls for novel model systems to investigate the biological impact of GALC down-regulation and for the search of novel therapeutic strategies in GLD. Zebrafish (Danio rerio) represents an attractive vertebrate model for human diseases. Here, lysosomal GALC activity was demonstrated in the brain of zebrafish adults and embryos. Accordingly, we identified two GALC co-orthologs (named galca and galcb) dynamically co-expressed in CNS during zebrafish development. Both genes encode for lysosomal enzymes endowed with GALC activity. Single down-regulation of galca or galcb by specific antisense morpholino oligonucleotides results in a partial decrease of GALC activity in zebrafish embryos that was abrogated in double galca/galcb morphants. However, no psychosine accumulation was observed in galca/galcb double morphants. Nevertheless, double galca/galcb knockdown caused reduction and partial disorganization of the expression of the early neuronal marker neuroD and an increase of apoptotic events during CNS development. These observations provide new insights into the pathogenesis of GLD, indicating that GALC loss-of-function may have pathological consequences in developing CNS independent of psychosine accumulation. Also, they underscore the potentiality of the zebrafish system in studying the pathogenesis of lysosomal neurodegenerative diseases, including GLD.
Zebrafish embryo is emerging as an important tool for behavior analysis as well as toxicity testing. In this study, we compared the effect of nine different methylxanthine drugs using zebrafish embryo as a model. We performed behavioral analysis, biochemical assay and Fish Embryo Toxicity (FET) test in zebrafish embryos after treatment with methylxanthines. Each drug appeared to behave in different ways and showed a distinct pattern of results. Embryos treated with seven out of nine methylxanthines exhibited epileptic-like pattern of movements, the severity of which varied with drugs and doses used. Cyclic AMP measurement showed that, despite of a significant increase in cAMP with some compounds, it was unrelated to the observed movement behavior changes. FET test showed a different pattern of toxicity with different methylxanthines. Each drug could be distinguished from the other based on its effect on mortality, morphological defects and teratogenic effects. In addition, there was a strong positive correlation between the toxic doses (TC 50 ) calculated in zebrafish embryos and lethal doses (LD 50 ) in rodents obtained from TOXNET database. Taken together, all these findings elucidate the potentiality of zebrafish embryos as an in vivo model for behavioral and toxicity testing of methylxanthines and other related compounds.
γ-Oryzanol (ORY) is well known for its antioxidant potential. However, the mechanism by which ORY exerts its antioxidant effect is still unclear. In this paper, the antioxidant properties of ORY were investigated for its potential effects as a reactive oxygen and nitrogen species (ROS/RNS) scavenger and in activating antioxidant-promoting intracellular pathways utilizing the human embryonic kidney cells (HEK-293). The 24 h ORY exposure significantly prevented hydrogen peroxide- (H2O2-) induced ROS/RNS production at 3 h, and this effect was sustained for at least 24 h. ORY pretreatment also enhanced the activity of antioxidant enzymes: superoxide dismutase (SOD) and glutathione peroxidase (GPX). Interestingly, ORY induced the nuclear factor (erythroid-derived 2)-like 2 (Nrf2) nuclear translocation and upregulation of Nrf2-dependent defensive genes such as NAD(P)H quinone reductase (NQO1), heme oxygenase-1 (HO-1), and glutathione synthetase (GSS) at mRNA and protein levels in both basal condition and after H2O2 insult. Thus, this study suggested an intriguing effect of ORY in modulating the Nrf2 pathway, which is also involved in regulating longevity as well as age-related diseases.
BackgroundZebrafish embryos are emerging as a model for pharmacological and toxicological studies. We used zebrafish embryos to study the general toxicity and cardiovascular effects of eight methylxanthines: aminophylline, caffeine, diprophylline, doxofylline, etophylline, 3-isobutyl-1-methylxanthine (IBMX), pentoxifylline and theophylline.MethodsMicroinjections of the eight methylxanthines were performed in 1-2 cell stage zebrafish embryos and the general toxicity and cardiovascular effects were analyzed at different time points. Embryotoxicity and teratogenicity were evaluated to understand the general toxicity of these compounds. Structural and functional alterations of the heart were evaluated to assess the cardiovascular effects.ResultsOur results showed different activity patterns of the methylxanthines drugs. Caffeine, IBMX, pentoxifylline and theophylline were highly embryotoxic and teratogenic; aminophylline, doxofylline and etophylline were embryotoxic and teratogenic only at higher doses, and diprophylline showed a minimal (<10%) embryotoxicity and teratogenicity. Most of these drugs induced structural alteration of the heart in 20-40% of the injected embryos with the maximum dose. This structural alteration was fatal with the embryos ultimately dying within 120 hpf. All the drugs induced a transient increase in heart rate at 48 hpf which returned to baseline within 96 hpf. This functional effect of methylxanthines showed similarity to the studies done in humans and other vertebrates.ConclusionOur results indicate the potential toxicity and teratogenicity of different methylxanthines in the embryos during embryonic development, the most sensitive period of life. Although interspecies differences need to be considered before drawing any conclusion, our study elucidated that a single exposure of methylxanthines at therapeutic range could induce cardiac dysfunction besides causing embryotoxicity and teratogenicity. Of all the drugs, diprophylline appeared to be safer, with lower degree of embryotoxicity, teratogenicity and cardiac toxicity as compared to other methylxanthines.Electronic supplementary materialThe online version of this article (10.1186/s40360-017-0179-9) contains supplementary material, which is available to authorized users.
BackgroundAuthorization to market a biosimilar product by the appropriate institutions is expected based on biosimilarity with its originator product. The analogy between the originator and its biosimilar(s) is assessed through safety, purity, and potency analyses.ObjectiveIn this study, we proposed a useful quality control system for rapid and economic primary screening of potential biosimilar drugs. For this purpose, chemical and functional characterization of the originator rhEPO alfa and two of its biosimilars was discussed.MethodsQualitative and quantitative analyses of the originator rhEPO alfa and its biosimilars were performed using reversed-phase high-performance liquid chromatography (RP-HPLC). The identification of proteins and the separation of isoforms were studied using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF–MS) and two-dimensional gel electrophoresis (2D-PAGE), respectively. Furthermore, the biological activity of these drugs was measured both in vitro, evaluating the TF-1 cell proliferation rate, and in vivo, using the innovative experimental animal model of the zebrafish embryos.ResultsChemical analyses showed that the quantitative concentrations of rhEPO alfa were in agreement with the labeled claims by the corresponding manufacturers. The qualitative analyses performed demonstrated that the three drugs were pure and that they had the same amino acid sequence. Chemical differences were found only at the level of isoforms containing N-glycosylation; however, functional in vitro and in vivo studies did not show any significant differences from a biosimilar point of view.ConclusionThese rapid and economic structural and functional analyses were effective in the evaluation of the biosimilarity between the originator rhEPO alfa and the biosimilars analyzed.Electronic supplementary materialThe online version of this article (doi:10.1007/s40259-015-0136-3) contains supplementary material, which is available to authorized users.
Abiraterone acetate (AbiAc) inhibits tumor growth when administered to immunodeficient mice engrafted with the in vitro cell model of human adrenocortical carcinoma (ACC). Here, we developed and validated a zebrafish model engrafted with cortisol-secreting ACC cells to study the effects of AbiAc on tumor growth. The experimental conditions for AbiAc absorption in AB zebrafish embryos including embryo number, AbiAc concentration, and absorption time curve by liquid chromatography–tandem mass spectrometry were set up. The AbiAc effect on steroid production in AB zebrafish embryos was measured as well. ACC cells (the NCI-H295R cell line, the primary cell ACC29, and the negative control cell SW13) were treated with drug-induced liver injury fluorescent dye, and ∼240 cells per 4 nL was injected in the subperidermal space of the yolk sac of AB zebrafish embryos (n = 80 ± 10). The cell area was measured with Noldus DanioScopeTM software. AbiAc absorption in AB zebrafish embryos was stage dependent. Abiraterone (Abi) concentration decreased, whereas its main metabolite, Δ4A, increased. Accordingly, we demonstrated that zebrafish expressed mRNA encoding the enzyme 3β-hydroxysteroid dehydrogenase, which converts Abi in Δ4A. Furthermore, ABiAc reduced cortisol production and increased progesterone in zebrafish embryos. Three days after cell injection, the cortisol-secreting ACC cell area in solvent-treated embryos was significantly higher than that in 1 µM AbiAC‒treated embryos, whereas no AbiAc effect was observed in SW13 cells, which lack the Abi target enzyme CYP17A1.Zebrafish embryos xenografted with ACC tumor cells could be a useful, fast, and reproducible experimental model to preclinically test the activity of new drugs in human ACC.
Biotoxicity tests are used to evaluate potential harmful effects of chemical substances. Among them, zebrafish embryo toxicity test is a well‐established procedure to study the negative effects of heavy metals. In respect to this, the measurement of the metal content accumulated in embryos during the toxicity test may help to understand adverse effects and identify target organs. However, because of the small masses involved, an analytical technique with high sensitivity is required.In this work, elemental chemical analysis of individual embryos was performed by means of total reflection X‐ray fluorescence to study Pb and Zn bioaccumulation. A suitable protocol for sample preparation and total reflection X‐ray fluorescence analysis was developed. At the end of fish embryo toxicity tests, zebrafish embryos exposed to Pb and Zn reference solutions or to leaching solutions of toxic and inertized municipal solid waste incinerator fly ashes were analyzed. A significant trend of bioaccumulation was observed for Pb with values one order of magnitude higher than the expected. Copyright © 2015 John Wiley & Sons, Ltd.
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