3Rs toxicity testing and disease modeling projects in the European Horizon 2020 research and innovation program

The 3Rs concept, calling for replacement, reduction and refinement of animal experimentation, is receiving increasing attention around the world, and has found its way to legislation, in particular in the European Union. This is aligned by growing efforts of the European Commission to support development and implementation of 3Rs methods. The present paper gives an overview of European 3Rs initiatives as part of the different pillars of the Horizon 2020 framework program for research and innovation. Focus is hereby put on projects that address the 3Rs concept in the context of toxicity testing, chemical risk assessment and disease modeling

Dataset on transcriptomic profiling of cholestatic liver injury in an in vitro and in vivo animal model

The transcriptomic dataset (whole genome microarray Affymetrix Human U133 plus 2.0 and Affymetrix Mouse Genome 430 2.0) presented in this paper describes the differential gene expression profile of a human in vitro model of drug-induced cholestasis and a well-known mouse in vivo model of cholestasis. The in vitro model consists of human hepatoma HepaRG cells in monolayer configuration exposed to 3 different cholestatic drugs with or without bile acids. For in vivo modelling of cholestasis, mice were subjected to bile duct ligation surgery. Consecutive normalization, summarization and background adjustments have been made by means of Robust Multichip Average Express software. (C) 2020 The Author(s). Published by Elsevier Inc

Поетеса Афінаїда і проблема становлення візантійського героїчного епосу

В статье рассматривается малоизученная проблема возникновения эпических поэм в ранневизантийской литературе ІІІ-IV веков н.э. Главный объект рассмотрения – творчество поэтессы Афинаиды (Евдокии) и ее поэма "О святом Киприане".В статті розглядається маловивчена проблема виникнення епічних поем в ранній візантійській літературі ІІІ-IV століть н.е. Головний об'єкт розгляду – творчість поетеси Афінаїди (Євдокії) і її поема "Про Святого Кіпріана".In the article – the practically non-considered problem of epic appearing of the early Byzantine literature (ІІІ-IV centuries AD). The main subject-matter under consideration is the creative works by Athenais (Eudokia) and her poem "About Saint Cyprian"

Inhibition of Connexin43 hemichannels impairs spatial short-term memory without affecting spatial working memory

Astrocytes are active players in higher brain function as they can release gliotransmitters, which are essential for synaptic plasticity. Various mechanisms have been proposed for gliotransmission, including vesicular mechanisms as well as non-vesicular ones, for example by passive diffusion via connexin hemichannels (HCs). We here investigated whether interfering with connexin43 (Cx43) HCs influenced hippocampal spatial memory. We made use of the peptide Gap19 that blocks HCs but not gap junction channels and is specific for Cx43. To this end, we microinfused transactivator of transcription linked Gap19 (TAT-Gap19) into the brain ventricle of male NMRI mice and assessed spatial memory in a Y maze. We found that the in vivo blockade of Cx43 HCs did not affect the locomotor activity or spatial working memory in a spontaneous alternation Y maze task. Cx43 blockade did however significantly impair the spatial short-term memory in a delayed spontaneous alternation Y maze task. These results indicate that Cx43 HCs play a role in spatial short-term memory

Astrocytic Connexin43 channels as candidate targets in epilepsy treatment

In epilepsy research, emphasis is put on exploring non-neuronal targets such as astrocytic proteins, since many patients remain pharmacoresistant to current treatments, which almost all target neuronal mechanisms. This paper reviews available data on astrocytic connexin43 (Cx43) signaling in seizures and epilepsy. Cx43 is a widely expressed transmembrane protein and the constituent of gap junctions (GJs) and hemichannels (HCs), allowing intercellular and extracellular communication, respectively. A plethora of research papers show altered Cx43 mRNA levels, protein expression, phosphorylation state, distribution and/or functional coupling in human epileptic tissue and experimental models. Human Cx43 mutations are linked to seizures as well, as 30% of patients with oculodentodigital dysplasia (ODDD), a rare genetic condition caused by mutations in the GJA1 gene coding for Cx43 protein, exhibit neurological symptoms including seizures. Cx30/Cx43 double knock-out mice show increased susceptibility to evoked epileptiform events in brain slices due to impaired GJ-mediated redistribution of K+ and glutamate and display a higher frequency of spontaneous generalized chronic seizures in an epilepsy model. Contradictory, Cx30/Cx43 GJs can traffic nutrients to high-energy demanding neurons and initiate astrocytic Ca2+ waves and hyper synchronization, thereby supporting proconvulsant effects. The general connexin channel blocker carbenoxolone and blockers from the fenamate family diminish epileptiform activity in vitro and improve seizure outcome in vivo. In addition, interventions with more selective peptide inhibitors of HCs display anticonvulsant actions. To conclude, further studies aiming to disentangle distinct roles of HCs and GJs are necessary and tools specifically targeting Cx43 HCs may facilitate the search for novel epilepsy treatments

Development and characterization of a new human hepatic cell line

The increasing demand and hampered use of primary human hepatocytes for research purposes have urged scientists to search for alternative cell sources, such as immortalized hepatic cell lines. The aim of this study was to develop a human hepatic cell line using the combined overexpression of TERT and the cell cycle regulators cyclin D1 and mutant isoform CDK4R24C. Following transduction of adult human primary hepatocytes with the selected immortalization genes, cell growth was triggered and a cell line was established. When cultured under appropriate conditions, the cell line expressed several hepatocytic markers and liver-enriched transcription factors at the transcriptional and/or translational level, secreted liver-specific proteins and showed glycogen deposition. These results suggest that the immortalization strategy applied to primary human hepatocytes could generate a novel hepatic cell line that seems to retain some key hepatic characteristics

Development and characterization of a new human hepatic cell line

The increasing demand and hampered use of primary human hepatocytes for research purposes have urged scientists to search for alternative cell sources, such as immortalized hepatic cell lines. The aim of this study was to develop a human hepatic cell line using the combined overexpression of TERT and the cell cycle regulators cyclin D1 and mutant isoform CDK4R24C. Following transduction of adult human primary hepatocytes with the selected immortalization genes, cell growth was triggered and a cell line was established. When cultured under appropriate conditions, the cell line expressed several hepatocytic markers and liver-enriched transcription factors at the transcriptional and/or translational level, secreted liver-specific proteins and showed glycogen deposition. These results suggest that the immortalization strategy applied to primary human hepatocytes could generate a novel hepatic cell line that seems to retain some key hepatic characteristics

Effects of Trichostatin A on drug uptake transporters in primary rat hepatocyte cultures

The present study was set up to investigate the effects of Trichostatin A (TSA), a prototypical epigenetic modifier, on the expression and activity of hepatic drug uptake transporters in primary cultured rat hepatocytes. To this end, the expression of the sinusoidal transporters sodium-dependent taurocholate cotransporting polypeptide (Ntcp) and organic anion transporting polypeptide 4 (Oatp4) was monitored by real-time quantitative reverse transcriptase polymerase chain reaction analysis and immunoblotting. The activity of the uptake transporters was analyzed using radiolabeled substrates and chemical inhibitors. Downregulation of the expression and activity of Oatp4 and Ntcp was observed as a function of the cultivation time and could not be counteracted by TSA. In conclusion, the epigenetic modifier TSA does not seem to exert a positive effect on the expression and activity of the investigated uptake transporters in primary rat hepatocyte cultures

Rodent models of cholestatic liver disease : a practical guide for translational research

Cholestatic liver disease denotes any situation associated with impaired bile flow concomitant with a noxious bile acid accumulation in the liver and/or systemic circulation. Cholestatic liver disease can be subdivided into different types according to its clinical phenotype, such as biliary atresia, drug-induced cholestasis, gallstone liver disease, intrahepatic cholestasis of pregnancy, primary biliary cholangitis and primary sclerosing cholangitis. Considerable effort has been devoted to elucidating underlying mechanisms of cholestatic liver injuries and explore novel therapeutic and diagnostic strategies using animal models. Animal models employed according to their appropriate applicability domain herein play a crucial role. This review provides an overview of currently available in vivo animal models, fit-for-purpose in modelling different types of cholestatic liver diseases. Moreover, a practical guide and workflow is provided which can be used for translational research purposes, including all advantages and disadvantages of currently available in vivo animal models

Cell junctions and oral health

The oral cavity and its appendices are exposed to considerable environmental and mechanical stress. This frequently involves cell junctions, which are goalkeepers of tissue homeostasis. Among those, gap junctions permit the exchange of compounds between cells, thereby controlling processes such as cell growth and differentiation. Tight junctions restrict paracellular transportation and inhibit movement of integral membrane proteins between the different plasma membrane poles. Adherens junctions attach cells one to another and provide a solid backbone for resisting to mechanistical stress. The integrity of oral mucosa, normal tooth development and saliva secretion depends on the proper function of all these types of cell junctions. Furthermore, deregulation of junctional proteins and/or mutations in their genes can alter tissue functioning and may result in various human disorders, including dental and periodontal problems, salivary gland malfunction, hereditary and infectious diseases as well as tumorigenesis. The present paper reviews the role of cell junctions in the (patho)physiology of the oral cavity and its appendices