18 research outputs found

    Involvement of p63 in the herpes simplex virus-1-induced demise of corneal cells

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    <p>Abstract</p> <p>Background</p> <p>The transcription factor p63 plays a pivotal role in the development and maintenance of epithelial tissues, including the ocular surface. In an effort to gain insight into the pathogenesis of keratitis caused by HSV-1, we determined the expression patterns of the p63 and Bax proteins in the Staatens Seruminstitute Rabbit Cornea cell line (SIRC).</p> <p>Methods</p> <p>SIRC cells were infected with HSV-1 at various multiplicities and maintained for different periods of time. Virus replication was measured by indirect immunofluorescence assay and Western blot analysis. Cell viability was determined by MTT assay. The apoptotic response of the infected cells was quantified by ELISA detecting the enrichment of nucleosomes in the cytoplasm. Western blot analysis was used to determine the levels of p63 and Bax proteins.</p> <p>Results</p> <p>Indirect immunofluorescence assays and Western blot analyses demonstrated the presence of HSV-1 glycoprotein D (gD) in the infected SIRC cell line, and the pattern of gD expression was consistent with efficient viral replication. The results of MTT and ELISA assays showed that HSV-1 elicited a strong cytopathic effect, and apoptosis played an important role in the demise of the infected cells. Mock-infected SIRC cells displayed the constitutive expression of ΔNp63α. The expressions of the Bax-β and TAp63γ isoforms were considerably increased, whereas the level of ΔNp63α was decreased in the HSV-1-infected SIRC cells. Experiments involving the use of acyclovir showed that viral DNA replication was necessary for the accumulation of TAp63γ.</p> <p>Conclusion</p> <p>These data suggest that a direct, virus-mediated cytopathic effect may play an important role in the pathogenic mechanism of herpetic keratitis. By disturbing the delicate balance between the pro-survival ΔN and the pro-apoptotic TA isoforms, HSV-1 may cause profound alterations in the viability of the ocular cells and in the tissue homeostasis of the ocular surface.</p

    Can Triplet Loss Be Used for Multi-Label Few-Shot Classification? A Case Study

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    Few-shot learning is a deep learning subfield that is the focus of research nowadays. This paper addresses the research question of whether a triplet-trained Siamese network, initially designed for multi-class classification, can effectively handle multi-label classification. We conducted a case study to identify any limitations in its application. The experiments were conducted on a dataset containing Hungarian legal decisions of administrative agencies in tax matters belonging to a major legal content provider. We also tested how different Siamese embeddings compare on classifying a previously non-existing label on a binary and a multi-label setting. We found that triplet-trained Siamese networks can be applied to perform classification but with a sampling restriction during training. We also found that the overlap between labels affects the results negatively. The few-shot model, seeing only ten examples for each label, provided competitive results compared to models trained on tens of thousands of court decisions using tf-idf vectorization and logistic regression

    Mondatszám-meghatározás hatása a magyar nyelvű jogi szövegek extraktív kivonatainak minőségére

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    Az egyes dokumentumok tartalmi összefoglalása során a cél egy dokumentum rövidebb változatának előállítása úgy, hogy annak fő információtartalma a kivonatban megőrződjön. Cikkünkben az anonimizált bírósági határozatokhoz készült extraktív kivonatoló rendszer fejlesztése során szerzett tapasztalatokat ismertetjük, különös tekintettel a kivonatok hosszával (mondatszám) kapcsolatban felmerült kérdésekre, és az azokra adott válaszainkra. A kivonatokkal egy jogi adatbázis felhasználóinak találati listában való könnyebb orientációját kívántuk támogatni

    Mondatszám-meghatározás hatása a magyar nyelvű jogi szövegek extraktív kivonatainak minőségére

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    Az egyes dokumentumok tartalmi összefoglalása során a cél egy dokumentum rövidebb változatának előállítása úgy, hogy annak fő információtartalma a kivonatban megőrződjön. Cikkünkben az anonimizált bírósági határozatokhoz készült extraktív kivonatoló rendszer fejlesztése során szerzett tapasztalatokat ismertetjük, különös tekintettel a kivonatok hosszával (mondatszám) kapcsolatban felmerült kérdésekre, és az azokra adott válaszainkra. A kivonatokkal egy jogi adatbázis felhasználóinak találati listában való könnyebb orientációját kívántuk támogatni

    Fehérjék konformációs dinamikája mint a biomolekuláris felismerés és jelátvitel meghatározó eleme = Protein conformational dynamics as a key determinant in biomolecular recognition and signal transmission

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    A térszerkezet alapján, a konformációs dinamika figyelembevételével kíséreltük meg az intramolekuláris és molekulák közötti jelátvitel megértését atomi felbontással. Kísérleti objektumok: a komplement rendszer, azon belül is a nemrég felfedezett lektin út fehérjekomplexei, a flagelláris exportrendszer valamint moduláris monomer, dimer és oligomer felépítésű enzimek álltak. Megállapítottuk, hogy FliI ATPáz, amely képes az exportálandó fehérjéje kitekerésére, a FliJ, FliH és FliS komponensekkel együtt képez olyan szupramolekuláris komplexet, amely képes az export szubsztrátumok felismerésére. Leírtuk a foszfoglicerát kináz enzim alloszterikus működési mechanizmusát, atomi felbontással. Feltártuk az izopropilmalát dehidrogenáz molekuláris csuklóinak működését és szerepét az alegységek kölcsönhatásaiban. Szelektív inhibitorokkal a tankönyvi tézissel ellentétes felismerésre jutottunk, miszerint a komplement rendszer lektin útjának meghatározó aktivátora a MASP-1 szerin proteáz. Így a komplement aktiválással összefüggő betegségek új gyógyszercélpont molekuláját azonosítottuk. Felfedeztük, hogy a MASP-1 képes a kininogén hasítása útján, bradikinint felszabadítva, komplement függő gyulladást keltésére. Felfedeztük, hogy a trombinhoz hasonlóan a MASP-1, PAR-4 receptoron keresztül endotél sejteket aktivál. Bizonyítékot találtunk arra, hogy a fehérjék konformációs dinamikája meghatározza a szerkezet evolúciójának lehetséges irányait, több milliárd éves időskálán is. | The CUB2 domain of C1r without calcium has disordered structure. This flexibility, necessary for autocativation of C1r inside the C1 complex, is regulated by calcium. Using MASP-selective inhibitors we proved that, in contrast to the previous textbook picture, MASP-1 is the exclusive activator of MASP-2. Blocking the proteolytic activity of MASP-1 prevents activation of the lectin pathway, therefore MASP-1 is a new target in treating complement related diseases. We solved the structure of the catalytic region of MASP-1. The structure explains the special enzymatic characteristics of this complement protease. We discovered a new, inflammation related function of the complement system: MASP-1 is able to directly activate endothelial cells through cleaving protease activated receptor-4. We discovered that MASP-1 is able to cleave kininogen and liberates bradykinin. In this way MASP-1 can contribute to the local inflammatory reaction triggered by complement activation. The allosteric mechanismnof human PGK has been explored at atomic details. In the dimeric enzyme IPMDH structural and site-directed mutagenesis studies revealed the operation of the two main molecular hinges and their relationship with the subunit interactions. We have shown that conformational motions are linked to protein evolution by producing structural variants that can be evolutionarily stabilized. This process is exemplified by segment-swapped proteins, a new group of proteins discovered by us

    Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

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    In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field
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