Gogolj, Melville in Fran Erjavec

Razprava se posveča primerjavi treh pripovedi o liku in usodi pisarja, nastalih sredi 19. stoletja: Gogoljevem Plašču, Melvillovem Batrtlebyju in Ervajčevemu Aguštinu Ocepku. Njen namen je raziskati in utemeljiti razlike v oblikovanju istega motiva v ruski, ameriški in slovenski literaturi, tako formalne kot vsebinske. Razlaga jih iz socialnozgodovinskega, socialnokulturnega in duhovnozgodovinskega ozadja, iz katerega so nastale pripovedi treh avtorjev oziroma treh literatur

Zgodnja dela Antona Tomaža Linharta

Linhartovo zgodnje pesništvo (Blumen aus Krain) in Dramatika (Miss Jenny Love), oboje pisano v nemščini, sta postala predmet večje znanstvene pozornosti v zadnjih desetletjih. Razprava preverja pridobljena dognanja in se na tej podlagi posveča odprtim vprašanjem - na katero pesniško oziroma dramsko tradicijo se navezujejo Linhartova zgodnja dela, zakaj se je Linhart odrekel izvirnemu pesnjenju in dramski ustvrjalnosti ter kakšen je pomen teh del za njegovo poznejšo dramsko-gledališko poustvarjalnost v obliki prirejanja tujih dramskih besedil za slovenske gledališke potrebe

Cytokeratin 8 ectoplasmic domain binds urokinase-type plasminogen activator to breast tumor cells and modulates their adhesion, growth and invasiveness

<p>Abstract</p> <p>Background</p> <p>Generation of plasmin is a characteristic of tumor cells, promoting the degradation of extracellular matrix, tumor progression and metastasis. The process is accelerated if plasminogen and plasminogen activator are bound to their cell surface receptors.</p> <p>Results</p> <p>In this study we show that the monoclonal antibody that recognizes an epitope on the cytokeratin 8 (CK8) ectoplasmic domain (anti-CK MAb) inhibits plasminogen activation mediated by urokinase-type plasminogen activator (uPA) in MCF-7 and MCF-10A neoT cells. The ectoplasmic domain of CK8 acts as a binding site for plasminogen, however, by using confocal microscopy, we demonstrated that it is also co-localized with uPA. CK8, therefore, function also as a receptor for uPA on the cell surface, and the presence of anti-CK MAb may prevent the binding of uPA to a designated CK8 motif. The consequent inhibition of plasmin generation resulted in changed cell morphology, enhanced cell adhesion to fibronectin, reduced invasion potential, and an enhanced G1/S transition. Moreover, surface plasmon resonance analysis showed that the synthetic dodecapeptide corresponding to the epitope sequence (VKIALEVEIATY), binds uPA in the nanomolar range.</p> <p>Conclusion</p> <p>These novel findings suggest a model in which CK8, together with uPA, plasminogen and fibronectin, constitutes a signaling platform capable of modulating cell adhesion/growth-dependent signal transduction in breast tumor cells. Anti-CK MAb, which competes for the binding site for uPA, could be used as an agent to reduce the invasive potential of breast tumor cells.</p

Upregulation of Cysteine Protease Cathepsin X in the 6-Hydroxydopamine Model of Parkinson’s Disease

Parkinson’s disease (PD) is a neurodegenerative disorder characterized by loss of midbrain dopaminergic neurons in the substantia nigra pars compacta (SNc). In vitro, a contribution to neuroinflammation and neurotoxicity has been shown for the lysosomal protease cathepsin X; however, its expression and its role in PD remain unknown. Therefore, the current study was designed to address the regional, cellular, and subcellular localization and activity of cathepsin X in hemi-parkinsonian rats with 6-hydroxydopamine (6-OHDA)-induced excitotoxicity in the unilateral medial forebrain bundle (MFB) lesion. We report for the first time that cathepsin X expression and activity are rapidly increased in the ipsilateral SNc after injection of 6-OHDA into the MFB reaching a maximum after 12 h but seem to stay strongly upregulated after 4 weeks after injection. At early time points of 6-OHDA injection into the MFB, the increased cathepsin X is localized in the lysosomes in the neuronal, predominantly tyrosine hydroxylase-positive dopaminergic cells. After 12 h of 6-OHDA induced lesion, only a few activated microglial cells are positive for cathepsin X whereas, in 4 weeks post-lesion accompanied with complete loss of dopaminergic neurons, there is persistent cathepsin X upregulation restricted to activated glia cells. Taken together, our results demonstrate that cathepsin X upregulation in the lesioned dopaminergic system may play a role as a pathogenic factor in PD. Moreover, inhibition of cathepsin X expression or activity may be useful in protecting the nigrostriatal dopaminergic projection in the PD

Možnosti uporabe protimikrobnih učinkovin pri zdravljenju raka

Rak je veliko breme za zdravstvene sisteme in še vedno drugi najpogostejši vzrok smrti v razvitem svetu. Zato se, kljub velikem napredku v zadnjih letih, še vedno veliko sredstev usmerja v iskanje novih učinkovitejših protitumorskih zdravil, ki bi omogočila bolj učinkovito zdravljenje, daljše preživetje bolnikov z rakom, preprečila ponovni pojav raka in zmanjšala stranske učinke, povezane z zdravljenjem raka, s tem pa povečala kakovost življenja bolnikov z rakom. Uvajanje novih zdravil v klinično uporabo pa je hkrati povezano z vse večjimi stroški. Zato je zaradi velike potrebe po prepoznavanju novih protitumorskih zdravil iskanje novih indikacij za že obstoječa zdravila na področju onkologije pritegnilo veliko pozornosti. Pri tem se je med drugim protitumorsko delovanje pokazalo tudi za nekatere antibiotike in druge protimikrobne učinkovine. Slednje se je med drugim izkazalo za doksiciklin, klorokin, nitroksolin in nekatere predstavnike fluorokinolonov. V preglednem članku povzemamo različne molekulske mehanizme, uporabljene tumorske modele in raziskave, ki opredeljujejo njihovo protitumorsko delovanje. To so prikazale številne neodvisne študije tako in vitro kot in vivo, strukture obstoječih učinkovin pa so se hkrati uporabile kot spojine za razvoj novih derivatov in identificiranje strukturnih elementov, ki izboljšajo protitumorsko delovanje. Te raziskave tako kažejo na nove možnosti za uporabo že dobro znanih učinkovin, ki bi lahko razširile svoj spekter uporabe in samostojno ali v kombinaciji z že obstoječim zdravljenjem izboljšale uspešnost protitumorskega zdravljenja

Redox-Based Inactivation of Cysteine Cathepsins by Compounds Containing the 4-Aminophenol Moiety

BACKGROUND: Redox cycling compounds have been reported to cause false positive inhibition of proteases in drug discovery studies. This kind of false positives can lead to unusually high hit rates in high-throughput screening campaigns and require further analysis to distinguish true from false positive hits. Such follow-up studies are both time and resource consuming. METHODS AND FINDINGS: In this study we show that 5-aminoquinoline-8-ol is a time-dependent inactivator of cathepsin B with a k(inact)/K(I) of 36.7 ± 13.6 M(-1) s(-1) using enzyme kinetics. 5-Aminoquinoline-8-ol inhibited cathepsins H, L and B in the same concentration range, implying a non-specific mechanism of inhibition. Further analogues, 4-aminonaphthalene-1-ol and 4-aminophenol, also displayed time-dependent inhibition of cathepsin B with k(inact)/K(I) values of 406.4 ± 10.8 and 36.5 ± 1.3 M(-1) s(-1). No inactivation occurred in the absence of either the amino or the hydroxyl group, suggesting that the 4-aminophenol moiety is a prerequisite for enzyme inactivation. Induction of redox oxygen species (ROS) by 4-aminophenols in various redox environments was determined by the fluorescent probe 2',7'-dichlorodihydrofluorescein diacetate. Addition of catalase to the assay buffer significantly abrogated the ROS signal, indicating that H(2)O(2) is a component of the ROS induced by 4-aminophenols. Furthermore, using mass spectrometry, active site probe DCG-04 and isoelectric focusing we show that redox inactivation of cysteine cathepsins by 5-aminoquinoline-8-ol is active site directed and leads to the formation of sulfinic acid. CONCLUSIONS: In this study we report that compounds containing the 4-aminophenol moiety inactivate cysteine cathepsins through a redox-based mechanism and are thus likely to cause false positive hits in the screening assays for cysteine proteases

Cysteine Peptidase Cathepsin X as a Therapeutic Target for Simultaneous TLR3/4-mediated Microglia Activation

Microglia are resident macrophages in the central nervous system that are involved in immune responses driven by Toll-like receptors (TLRs). Microglia-mediated inflammation can lead to central nervous system disorders, and more than one TLR might be involved in these pathological processes. The cysteine peptidase cathepsin X has been recognized as a pathogenic factor for inflammation-induced neurodegeneration. Here, we hypothesized that simultaneous TLR3 and TLR4 activation induces synergized microglia responses and that these phenotype changes affect cathepsin X expression and activity. Murine microglia BV2 cells and primary murine microglia were exposed to the TLR3 ligand polyinosinic-polycytidylic acid (poly(I:C)) and the TLR4 ligand lipopolysaccharide (LPS), individually and simultaneously. TLR3 and TLR4 co-activation resulted in increased inflammatory responses compared to individual TLR activation, where poly(I:C) and LPS induced distinct patterns of proinflammatory factors together with different patterns of cathepsin X expression and activity. TLR co-activation decreased intracellular cathepsin X activity and increased cathepsin X localization at the plasma membrane with concomitant increased extracellular cathepsin X protein levels and activity. Inhibition of cathepsin X in BV2 cells by AMS36, cathepsin X inhibitor, significantly reduced the poly(I:C)- and LPS-induced production of proinflammatory cytokines as well as apoptosis. Additionally, inhibiting the TLR3 and TLR4 common signaling pathway, PI3K, with LY294002 reduced the inflammatory responses of the poly(I:C)- and LPS-activated microglia and recovered cathepsin X activity. We here provide evidence that microglial cathepsin X strengthens microglia activation and leads to subsequent inflammation-induced neurodegeneration. As such, cathepsin X represents a therapeutic target for treating neurodegenerative diseases related to excess inflammation