Inflammatory bowel disease (IBD) is a relapsing and remitting inflammatory disease affecting millions of people worldwide. The active phase of IBD is characterized by excessive formation of reactive oxygen species (ROS) in the intestinal mucosa, which further accelerates the inflammatory process. A feasible strategy for the IBD treatment is thus breaking the oxidation-inflammation vicious circle by scavenging excessive ROS with the use of a suitable antioxidant. Herein, we have developed a novel hydrogel system for oral administration utilizing sterically hindered amine-based redox polymer (SHARP) incorporating covalently bound antioxidant SHA groups. SHARP was prepared via free-radical polymerization by covalent crosslinking of 2-hydroxyethyl methacrylate (HEMA), poly(ethylene oxide) methyl ether methacrylate (PEGMA) and a SHA-based monomer, N-(2,2,6,6-tetramethyl-piperidin-4-yl)-methacrylamide. The SHARP hydrogel was resistant to hydrolysis and swelled considerably (∼90% water content) under the simulated gastrointestinal tract (GIT) conditions, and exhibited concentration-dependent antioxidant properties in vitro against different ROS. Further, the SHARP hydrogel was found to be non-genotoxic, non-cytotoxic, non-irritating, and non-absorbable from the gastrointestinal tract. Most importantly, SHARP hydrogel exhibited a statistically significant, dose-dependent therapeutic effect in the mice model of dextran sodium sulfate (DSS)-induced acute colitis. Altogether, the obtained results suggest that the SHARP hydrogel strategy holds a great promise with respect to IBD treatment.

• MeSH
• aminy MeSH
• hydrogely MeSH
• idiopatické střevní záněty * farmakoterapie   MeSH
• kolitida * chemicky indukované   farmakoterapie   MeSH
• myši MeSH
• oxidace-redukce MeSH
• polymery MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

New amphiphilic diblock polymer nanotherapeutics serving simultaneously as a drug delivery system and an inhibitor of multidrug resistance were designed, synthesized, and evaluated for their physico-chemical and biological characteristics. The amphiphilic character of the diblock polymer, containing a hydrophilic block based on the N-(2-hydroxypropyl)methacrylamide copolymer and a hydrophobic poly(propylene oxide) block (PPO), caused self-assembly into polymer micelles with an increased hydrodynamic radius (Rhof approximately 15nm) in aqueous solutions. Doxorubicin (Dox), as a cytostatic drug, was bound to the diblock polymer through a pH-sensitive hydrazone bond, enabling prolonged circulation in blood, the delivery of Dox into a solid tumor and the subsequent stimuli-sensitive controlled release within the tumor mass and tumor cells at a decreased pH. The applicability of micellar nanotherapeutics as drug carriers was confirmed by an in vivo evaluation using EL4 lymphoma-bearing C57BL/6 mice. We observed significantly higher accumulation of micellar conjugates in a solid tumor because of the EPR effect compared with similar polymer-drug conjugates that do not form micellar structures or with the parent free drug. In addition, highly increased anti-tumor efficacy of the micellar polymer nanotherapeutics, even at a sub-optimal dose, was observed. The presence of PPO in the structure of the diblock polymer ensured, during in vitro tests on human and mouse drug-sensitive and resistant cancer cell lines, the inhibition of P-glycoprotein, one of the most frequently expressed ATP-dependent efflux pump that causes multidrug resistance. In addition, we observed highly increased rate of the uptake of the diblock polymer nanotherapeutics within the cells. We suppose that combination of unique properties based on MDR inhibition, stimuli sensitiveness (pH sensitive activation of drug), improved pharmacokinetics and increased uptake into the cells made the described polymer micelle a good candidate for investigation as potential drug delivery system.

• MeSH
• akrylamidy aplikace a dávkování   chemie   farmakokinetika   terapeutické užití   MeSH
• antibiotika antitumorózní aplikace a dávkování   chemie   farmakokinetika   terapeutické užití   MeSH
• chemorezistence účinky léků   MeSH
• doxorubicin aplikace a dávkování   chemie   farmakokinetika   terapeutické užití   MeSH
• hydrofobní a hydrofilní interakce MeSH
• lidé MeSH
• micely * MeSH
• mnohočetná léková rezistence účinky léků   MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nádory farmakoterapie   metabolismus   patologie   MeSH
• nosiče léků aplikace a dávkování   chemie   farmakokinetika   terapeutické užití   MeSH
• polymery aplikace a dávkování   chemie   farmakokinetika   terapeutické užití   MeSH
• propylenglykoly aplikace a dávkování   chemie   farmakokinetika   terapeutické užití   MeSH
• tumor burden účinky léků   MeSH
• uvolňování léčiv MeSH
• viabilita buněk účinky léků   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Water-soluble N-(2-hydroxypropyl)methacrylamide copolymer conjugates bearing the anticancer drugs doxorubicin (Dox) or pirarubicin (THP), P-gp inhibitors derived from reversin 121 (REV) or ritonavir (RIT)), or both anticancer drug and P-gp inhibitor were designed and synthesized. All biologically active molecules were attached to the polymer carrier via pH-sensitive spacer enabling controlled release in mild acidic environment modeling endosomes and lysosomes of tumor cells. The cytotoxicity of the conjugates against three sensitive and Dox-resistant neuroblastoma (NB) cell lines, applied alone or in combination, was studied in vitro. All conjugates containing THP displayed higher cytotoxicity against all three Dox-resistant NB cell lines compared with the corresponding Dox-containing conjugates. Furthermore, the cytotoxicity of conjugates containing both drug and P-gp inhibitor was up to 10 times higher than that of the conjugate containing only drug. In general, the polymer-drug conjugates showed higher cytotoxicity when conjugates containing inhibitors were added 8 or 16h prior to treatment compared with conjugates bearing both the inhibitor and the drug. The difference in cytotoxicity was more pronounced at the 16-h time point. Moreover, higher inhibitor:drug ratios resulted in higher cytotoxicity. The cytotoxicity of the polymer-drug used in combination with polymer P-gp inhibitor was up to 84 times higher than that of the polymer-drug alone.

• MeSH
• antibiotika antitumorózní aplikace a dávkování   chemie   farmakologie   MeSH
• chemorezistence účinky léků   MeSH
• doxorubicin aplikace a dávkování   analogy a deriváty   chemie   farmakologie   MeSH
• lidé MeSH
• methakryláty aplikace a dávkování   chemie   MeSH
• mnohočetná léková rezistence účinky léků   MeSH
• nádorové buněčné linie MeSH
• neuroblastom genetika   metabolismus   MeSH
• oligopeptidy aplikace a dávkování   chemie   farmakologie   MeSH
• P-glykoprotein antagonisté a inhibitory   genetika   metabolismus   MeSH
• ritonavir aplikace a dávkování   chemie   farmakologie   MeSH
• uvolňování léčiv MeSH
• viabilita buněk účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

OBJECTIVE: Gonadotropin-releasing hormone (GnRH) antagonist combined with the human chorionic gonadotropin hormone (hCG) is commonly used in assisted reproduction techniques (ARTs) to induce controlled ovarian hyperstimulation (COH) and to synchronize oocyte maturation. While hCG is known to have immunomodulatory properties, we aimed to assess its effect on immunological changes, with respect to HLA-G binding receptors and embryo implantation success. DESIGN: The study involved 103 subjects, including patients undergoing COH protocols (n=66), divided on the basis of the pair's fertility disorder (FD) causes (female FD, n=29; male FD, n=37), and age matched healthy women (n=37). The relative distribution of T cell (CD3+/CD4+, CD3+/CD8+) and NK cell (CD56bright/CD16-, CD56dim/CD16+) populations was evaluated together with HLA-G ligands KIR2DL4 and LILRB1 expression by flow cytometry in the peripheral blood of all subjects, as well as in patient follicular fluids. RESULTS: Both groups of patients exhibited a significant decrease of their CD4/CD8 index, a down-modulation of LILRB1-positive CD8 T cells, and increased KIR2DL4-positive NK cell distribution, when compared to the healthy donors. We attribute these changes to the COH protocol, since the only significant change between the patient groups was in the number of cytotoxic CD56dim NK cells (elevated in the female FD group). Patients with male FD causes, having an above-average CD4/CD8 index (≥3.17) and below-average KIR2DL4+/CD56bright NK cell levels(≤13.3%), exhibited higher embryo implantation rates. CONCLUSION: The GnRH antagonist/hCG protocol promotes CD3+/CD8+ and KIR2DL4+ NK cell levels, more abundant in subjects with lower implantation rates, and thus decreases the embryotransfer success in otherwise fertile women.

• MeSH
• anovulace farmakoterapie   imunologie   MeSH
• asistovaná reprodukce MeSH
• biologické markery metabolismus   MeSH
• buňky NK účinky léků   imunologie   MeSH
• choriogonadotropin aplikace a dávkování   MeSH
• cytotoxické T-lymfocyty účinky léků   imunologie   MeSH
• dospělí MeSH
• hormon uvolňující gonadotropiny antagonisté a inhibitory   MeSH
• implantace embrya účinky léků   imunologie   MeSH
• kombinovaná farmakoterapie MeSH
• lidé MeSH
• mužská infertilita farmakoterapie   imunologie   MeSH
• ovulace účinky léků   imunologie   MeSH
• poměr CD4 a CD8 lymfocytů MeSH
• průtoková cytometrie MeSH
• těhotenství MeSH
• ženská infertilita farmakoterapie   imunologie   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• těhotenství MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• klinické zkoušky MeSH
• práce podpořená grantem MeSH

Translation is divided into initiation, elongation, termination and ribosome recycling. Earlier work implicated several eukaryotic initiation factors (eIFs) in ribosomal recycling in vitro. Here, we uncover roles for HCR1 and eIF3 in translation termination in vivo. A substantial proportion of eIF3, HCR1 and eukaryotic release factor 3 (eRF3) but not eIF5 (a well-defined "initiation-specific" binding partner of eIF3) specifically co-sediments with 80S couples isolated from RNase-treated heavy polysomes in an eRF1-dependent manner, indicating the presence of eIF3 and HCR1 on terminating ribosomes. eIF3 and HCR1 also occur in ribosome- and RNA-free complexes with both eRFs and the recycling factor ABCE1/RLI1. Several eIF3 mutations reduce rates of stop codon read-through and genetically interact with mutant eRFs. In contrast, a slow growing deletion of hcr1 increases read-through and accumulates eRF3 in heavy polysomes in a manner suppressible by overexpressed ABCE1/RLI1. Based on these and other findings we propose that upon stop codon recognition, HCR1 promotes eRF3·GDP ejection from the post-termination complexes to allow binding of its interacting partner ABCE1/RLI1. Furthermore, the fact that high dosage of ABCE1/RLI1 fully suppresses the slow growth phenotype of hcr1Δ as well as its termination but not initiation defects implies that the termination function of HCR1 is more critical for optimal proliferation than its function in translation initiation. Based on these and other observations we suggest that the assignment of HCR1 as a bona fide eIF3 subunit should be reconsidered. Together our work characterizes novel roles of eIF3 and HCR1 in stop codon recognition, defining a communication bridge between the initiation and termination/recycling phases of translation.

• MeSH
• ABC transportéry genetika   MeSH
• eukaryotický iniciační faktor 3 genetika   MeSH
• iniciační faktory genetika   MeSH
• mutace MeSH
• proteosyntéza * MeSH
• Saccharomyces cerevisiae - proteiny genetika   MeSH
• Saccharomyces cerevisiae genetika   MeSH
• sekvence aminokyselin MeSH
• terminace translace peptidového řetězce * MeSH
• terminační kodon genetika   MeSH
• vazba proteinů MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• Publikační typ
• abstrakt z konference MeSH

Translation initiation factor eIF3 acts as the key orchestrator of the canonical initiation pathway in eukaryotes, yet its structure is greatly unexplored. We report the 2.2 Å resolution crystal structure of the complex between the yeast seven-bladed β-propeller eIF3i/TIF34 and a C-terminal α-helix of eIF3b/PRT1, which reveals universally conserved interactions. Mutating these interactions displays severe growth defects and eliminates association of eIF3i/TIF34 and strikingly also eIF3g/TIF35 with eIF3 and 40S subunits in vivo. Unexpectedly, 40S-association of the remaining eIF3 subcomplex and eIF5 is likewise destabilized resulting in formation of aberrant pre-initiation complexes (PICs) containing eIF2 and eIF1, which critically compromises scanning arrest on mRNA at its AUG start codon suggesting that the contacts between mRNA and ribosomal decoding site are impaired. Remarkably, overexpression of eIF3g/TIF35 suppresses the leaky scanning and growth defects most probably by preventing these aberrant PICs to form. Leaky scanning is also partially suppressed by eIF1, one of the key regulators of AUG recognition, and its mutant sui1(G107R) but the mechanism differs. We conclude that the C-terminus of eIF3b/PRT1 orchestrates co-operative recruitment of eIF3i/TIF34 and eIF3g/TIF35 to the 40S subunit for a stable and proper assembly of 48S pre-initiation complexes necessary for stringent AUG recognition on mRNAs.

• MeSH
• eukaryotický iniciační faktor 1 genetika   MeSH
• eukaryotický iniciační faktor 3 chemie   genetika   metabolismus   MeSH
• fenotyp MeSH
• genová dávka MeSH
• iniciace translace peptidového řetězce MeSH
• kodon iniciační MeSH
• krystalografie rentgenová MeSH
• kvasinky genetika   růst a vývoj   MeSH
• malé podjednotky ribozomu eukaryotické metabolismus   MeSH
• molekulární modely MeSH
• mutace MeSH
• Saccharomyces cerevisiae - proteiny chemie   genetika   metabolismus   MeSH
• terciární struktura proteinů MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The ribosome translates information encoded by mRNAs into proteins in all living cells. In eukaryotes, its small subunit together with a number of eukaryotic initiation factors (eIFs) is responsible for locating the mRNA's translational start to properly decode the genetic message that it carries. This multistep process requires timely and spatially coordinated placement of eIFs on the ribosomal surface. In our long-standing pursuit to map the 40S-binding site of one of the functionally most complex eIFs, yeast multisubunit eIF3, we identified several interactions that placed its major body to the head, beak and shoulder regions of the solvent-exposed side of the 40S subunit. Among them is the interaction between the N-terminal domain (NTD) of the a/TIF32 subunit of eIF3 and the small ribosomal protein RPS0A, residing near the mRNA exit channel. Previously, we demonstrated that the N-terminal truncation of 200 residues in tif32-Δ8 significantly reduced association of eIF3 and other eIFs with 40S ribosomes in vivo and severely impaired translation reinitiation that eIF3 ensures. Here we show that not the first but the next 200 residues of a/TIF32 specifically interact with RPS0A via its extreme C-terminal tail (CTT). Detailed analysis of the RPS0A conditional depletion mutant revealed a marked drop in the polysome to monosome ratio suggesting that the initiation rates of cells grown under non-permissive conditions were significantly impaired. Indeed, amounts of eIF3 and other eIFs associated with 40S subunits in the pre-initiation complexes in the RPS0A-depleted cells were found reduced; consistently, to the similar extent as in the tif32-Δ8 cells. Similar but less pronounced effects were also observed with the viable CTT-less mutant of RPS0A. Together we conclude that the interaction between the flexible RPS0A-CTT and the residues 200-400 of the a/TIF32-NTD significantly stimulates attachment of eIF3 and its associated eIFs to small ribosomal subunits in vivo.

• MeSH
• eukaryotický iniciační faktor 3 metabolismus   MeSH
• genový knockout MeSH
• iniciace translace peptidového řetězce * MeSH
• interakční proteinové domény a motivy MeSH
• malé podjednotky ribozomu eukaryotické metabolismus   MeSH
• podjednotky proteinů metabolismus   MeSH
• ribozomální proteiny genetika   metabolismus   fyziologie   MeSH
• Saccharomyces cerevisiae - proteiny genetika   metabolismus   fyziologie   MeSH
• Saccharomyces cerevisiae metabolismus   MeSH
• techniky dvojhybridového systému MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Recent reports have begun unraveling the details of various roles of individual eukaryotic translation initiation factor 3 (eIF3) subunits in translation initiation. Here we describe functional characterization of two essential Saccharomyces cerevisiae eIF3 subunits, g/Tif35 and i/Tif34, previously suggested to be dispensable for formation of the 48S preinitiation complexes (PICs) in vitro. A triple-Ala substitution of conserved residues in the RRM of g/Tif35 (g/tif35-KLF) or a single-point mutation in the WD40 repeat 6 of i/Tif34 (i/tif34-Q258R) produces severe growth defects and decreases the rate of translation initiation in vivo without affecting the integrity of eIF3 and formation of the 43S PICs in vivo. Both mutations also diminish induction of GCN4 expression, which occurs upon starvation via reinitiation. Whereas g/tif35-KLF impedes resumption of scanning for downstream reinitiation by 40S ribosomes terminating at upstream open reading frame 1 (uORF1) in the GCN4 mRNA leader, i/tif34-Q258R prevents full GCN4 derepression by impairing the rate of scanning of posttermination 40S ribosomes moving downstream from uORF1. In addition, g/tif35-KLF reduces processivity of scanning through stable secondary structures, and g/Tif35 specifically interacts with Rps3 and Rps20 located near the ribosomal mRNA entry channel. Together these results implicate g/Tif35 and i/Tif34 in stimulation of linear scanning and, specifically in the case of g/Tif35, also in proper regulation of the GCN4 reinitiation mechanism.

• MeSH
• aminokyselinové motivy genetika   MeSH
• eukaryotický iniciační faktor 3 chemie   genetika   metabolismus   MeSH
• fungální RNA metabolismus   MeSH
• messenger RNA genetika   metabolismus   MeSH
• molekulární modely MeSH
• molekulární sekvence - údaje MeSH
• mutace MeSH
• podjednotky proteinů chemie   genetika   metabolismus   MeSH
• proteosyntéza MeSH
• ribozomální proteiny chemie   genetika   metabolismus   MeSH
• ribozomy genetika   metabolismus   MeSH
• Saccharomyces cerevisiae - proteiny chemie   genetika   metabolismus   MeSH
• Saccharomyces cerevisiae genetika   metabolismus   MeSH
• sekundární struktura proteinů MeSH
• sekvence aminokyselin MeSH
• sekvenční homologie aminokyselin MeSH
• substituce aminokyselin MeSH
• terciární struktura proteinů MeSH
• transkripční faktory bZIP genetika   metabolismus   MeSH
• vazba proteinů MeSH
• western blotting MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• Publikační typ
• abstrakty MeSH