STER1, a novel receptor-like kinase, functions in MAMP signalling in Arabidopsis

S. epidermidis has long been recognized as an important opportunistic pathogen accounting for the majority of nosocomial infections alongside S. aureus. However, in spite of this, our understanding of the S. epidermidis virulence mechanisms is still limited. Previous studies have emphasized various analogies in innate immunity against pathogens in plant, invertebrate and mammalian hosts. When compared to in vivo animal models, plant models are an attractive alternative and experiments using the S.aureus-Arabidopsis pathosystem have shown potential for this approach with S. epidermidis. In this study, an Arabidopsis−S.epidermidis system was established aiming to identify possible bacterial virulence traits. As S. epidermidis is not a true plant pathogen it fails to multiply in planta; however, most S. epidermidis strains tested generated a salycilic acid (SA)-dependent necrotic phenotype in Arabidopsis 5 days−post inoculation. Additionally, inoculation with boiled bacteria generated the same visual response as live cells, suggesting a pre−existent, heat stable molecule underlies the plant visual response. Taken together, this data suggests the necrotic response is a visual expression of MAMP perception. Subsequent exploitation of the Arabidopsis natural variation through QTL analysis, resulted in the isolation of the STER1 (Staphylococcus elicitor response 1) gene. This gene is essential for the visual response to S. epidermidis 18888 and encodes a membrane localized DUF26−containing receptor−like kinase. The ster1-1 mutant remained asymptomatic following inoculation with Gram−positive S. epidermidis 18888 and Gram−negative B. ambifaria, suggesting STER1’s likely role in the recognition of a common molecule. Peptidoglycan (PGN), an essential bacterial membrane component was considered a likely candidate and isolated from both species. Inoculation with B. ambifaria PGN generates a plant response that mirrores the one seen with bacterial suspensions of the same organism. By contrast, pure S. epidermidis 18888 PGN does not trigger a visual response in Arabidopsis. Instead, an S. epidermidis 18888 membrane fraction (MF), consisting of PGN, teichoic acid (TA) and an uncharacterized capsular polysaccharide (CPS), was found to generate a necrotic response similar to live cells. Treatment with S. epidermidis MF and B. ambifaria PGN triggered stereotypical defence responses, such as PR1 up−regulation and cell death in wild−type plants, but not in the ster1-1 mutant. Additionally, pre-treatment with S. epidermidis MF and B. ambifaria PGN also restricted Pst DC3000 growth in wild−type plants only, thus emphasizing a likely role for STER1 in basal resistance and PGN perception. In conclusion, the data obtained in this study implicate STER1 in PGN and possibly specialized CPS recognition, either as a receptor, co-receptor or essential signalling component

AGEs and Glucose Levels Modulate Type I and III Procollagen mRNA Synthesis in Dermal Fibroblasts Cells Culture

In the dermis, fibroblasts play an important role in the turnover of the dermal extracellular matrix. Collagen I and III, the most important dermal proteins of the extracellular matrix, are progressively altered during ageing and diabetes. For mimicking diabetic conditions, the cultured human dermal fibroblasts were incubated with increasing amounts of AGE-modified BSA and D-glucose for 24 hours. The expression of procollagen α2(I) and procollagen α1(III) mRNA was analyzed by quantitative real-time PCR. Our data revealed that the treatment of fibroblasts with AGE-modified BSA upregulated the expression of procollagen α2(I) and procollagen α1(III) mRNA in a dose-dependent manner. High glucose levels mildly induced a profibrogenic pattern, increasing the procollagen α2(I) mRNA expression whereas there was a downregulation tendency of procollagen α1(III) mRNA

BIOCHEMICAL AND HISTOLOGICAL EFFECTS OF DELTAMETHRIN EXPOSURE ON THE GILLS OF CARASSIUS AURATUS GIBELIO (Pisces Cyprinidae)

This study investigated the alterations in the activities of several antioxidant enzymesin the gills of the freshwater fish Carassius auratus gibelio exposed to deltamethrin.To get this goal, groups of 10 individuals were exposed for one, two, three, sevenand fourteen days to sublethal concentration of deltamethrin (2 g/L). Anothergroup was used as control. The activities of catalase, gluthatione peroxidase andgluthatione reductase were significantly decreased, while the glutathione-Stransferasewas up-regulated. All fish, exposed to 2glL deltamethrin revealed gillsmorphological alterations after 48h of exposure which were accentuated after 14days. In the gills hyperemia, fusion of secondary lamellae, epithelial layer ruptureand chloride cells proliferation were observed. These results suggest that animmediate adaptive response to the oxidative stress appeared, demonstratingalterations in the antoxidant defense mechanism in the gills of deltamethrinintoxicated fish

Water Soluble Pleurotus ostreatus Polysaccharide Down-Regulates the Expression of MMP-2 and MMP-9 in Caco-2 Cells

Many polysaccharides and polysaccharide-protein complexes isolated from mushrooms have immunomodulatory and anti-cancer effects. Our aim was to study the regulatory mechanisms of Caco-2 cell response to water soluble P. ostreatus polysaccharide extract up to 72 hours. Specific enzymatic activities were assessed by kinetic measurements. The reduced glutathione content and the lipid peroxidation level were also analyzed. Protein expression of several heat shock proteins, Bcl-2 and metalloproteinases 2 and 9 were revealed by Western blot. Gelatin zymography assay was used to evaluate the MMP-2 and MMP-9 activities. Until the third day of exposure the total SOD activity decreased continuously by 30%, whereas GST and GR ones diminished by 17% respectively 30.5% compared to control. No significant changes were observed in CAT and G6PDH specific activities as well as in GSH and MDA concentration. After the third day of exposure a significant up-regulation of Hsp60 and Hsp90 expression and a down-regulation of Hsp70 one were registered. Bcl-2 protein levels were down-regulated by 50% in the first day of treatment but increased after 3 days. MMP-2 and 9 secretion in the culture medium was significantly reduced suggesting a diminished ability of invasion of colon cancer cells. Our data revealed that in vitro treatment with P. ostreatus aqueous polysaccharide extract does not induce apoptosis in Caco-2 cell line but it could inhibit the invasion of colon cancer cells through the basement membrane

Intoxication with some pesticides induce release of cytochrome C and DNA fragmentation in human cell line Huh 7

USMF „N. Testemiţanu” Catedra Biochimie şi Biochimie Clinică; Universitatea din Bucureşti, Facultatea de Biologie, Catedra BiochimieLindane and deltametrine are insecticides with very large utilization in agriculture and public health wich are dangerous contaminants for human organism. We studied the capacity of lindane and deltametrin to induce release of cytochrome C and DNA fragmentation in human cell line Huh 7, as a posibele mecanism of toxiticity. Our results sugest that intoxication with lindane and deltametrin induce biochemical modifications related to apoptosis. Lindanul şi deltametrinul sunt insecticide pe larg utilizate în agricultură şi sănătate publică, periculoase ca contaminanţi pentru organismul uman. Noi am studiat capacitatea acestor insecticide de a provoca eliberarea citocromului c şi fragmentatrea ADN în culturi de hepatocite umane transformate Huh7, ca un posibil mecanism al toxicităţii lor urmat de declansarea prcesului apoptotic. Rezultatele obţinute, sugerează că intoxicaţia cu aceste pesticide induce modificările biochimice caracteristice apoptozei

Biomedical properties and preparation of iron oxide-dextran nanostructures by MAPLE technique

<p>Abstract</p> <p>Background</p> <p>In this work the chemical structure of dextran-iron oxide thin films was reported. The films were obtained by MAPLE technique from composite targets containing 10 wt. % dextran with 1 and 5 wt.% iron oxide nanoparticles (IONPs). The IONPs were synthesized by co-precipitation method. A KrF* excimer laser source (λ = 248 nm, τ_FWHM≅25 ns, ν = 10 Hz) was used for the growth of the hybrid, iron oxide NPs-dextran thin films.</p> <p>Results</p> <p>Dextran coated iron oxide nanoparticles thin films were indexed into the spinel cubic lattice with a lattice parameter of 8.36 Å. The particle sized calculated was estimated at around 7.7 nm. The XPS shows that the binding energy of the Fe 2p_3/2of two thin films of dextran coated iron oxide is consistent with Fe³⁺oxides. The atomic percentage of the C, O and Fe are 66.71, 32.76 and 0.53 for the films deposited from composite targets containing 1 wt.% maghemite and 64.36, 33.92 and 1.72 respectively for the films deposited from composite targets containing 5 wt.% maghemite. In the case of cells cultivated on dextran coated 5% maghemite γ-Fe₂O₃, the number of cells and the level of F-actin were lower compared to the other two types of thin films and control.</p> <p>Conclusions</p> <p>The dextran-iron oxide continuous thin films obtained by MAPLE technique from composite targets containing 10 wt.% dextran as well as 1 and 5 wt.% iron oxide nanoparticles synthesized by co-precipitation method presented granular surface morphology. Our data proved a good viability of Hep G2 cells grown on dextran coated maghemite thin films. Also, no changes in cells morphology were noticed under phase contrast microscopy. The data strongly suggest the potential use of iron oxide-dextran nanocomposites as a potential marker for biomedical applications.</p

Biomedical Properties and Preparation of Iron Oxide-Dextran Nanostructures by MAPLE Technique

Background: In this work the chemical structure of dextran-iron oxide thin films was reported. The films were obtained by MAPLE technique from composite targets containing 10 wt. % dextran with 1 and 5 wt.% iron oxide nanoparticles (IONPs). The IONPs were synthesized by co-precipitation method. A KrF* excimer laser source (λ = 248 nm, τFWHM≅25 ns, ν = 10 Hz) was used for the growth of the hybrid, iron oxide NPs-dextran thin films. Results: Dextran coated iron oxide nanoparticles thin films were indexed into the spinel cubic lattice with a lattice parameter of 8.36 Å. The particle sized calculated was estimated at around 7.7 nm. The XPS shows that the binding energy of the Fe 2p3/2 of two thin films of dextran coated iron oxide is consistent with Fe3+ oxides. The atomic percentage of the C, O and Fe are 66.71, 32.76 and 0.53 for the films deposited from composite targets containing 1 wt.% maghemite and 64.36, 33.92 and 1.72 respectively for the films deposited from composite targets containing 5 wt.% maghemite. In the case of cells cultivated on dextran coated 5% maghemite γ-Fe2O3, the number of cells and the level of F-actin were lower compared to the other two types of thin films and control. Conclusions: The dextran-iron oxide continuous thin films obtained by MAPLE technique from composite targets containing 10 wt.% dextran as well as 1 and 5 wt.% iron oxide nanoparticles synthesized by co-precipitation method presented granular surface morphology. Our data proved a good viability of Hep G2 cells grown on dextran coated maghemite thin films. Also, no changes in cells morphology were noticed under phase contrast microscopy. The data strongly suggest the potential use of iron oxide-dextran nanocomposites as a potential marker for biomedical applications

Characterization of Sucrose Thin Films for Biomedical Applications

Sucrose is a natural osmolyte accumulated in the cells of organisms as they adapt to environmental stress. In vitro sucrose increases protein stability and forces partially unfolded structures to refold. Thin films of sucrose (C12H22O11) were deposited on thin cut glass substrates by the thermal evaporation technique (P∼10−5 torr). Characteristics of thin films were put into evidence by Fourier Transform Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS), scanning electron microscopy (SEM), and differential thermal analysis and thermal gravimetric analysis (TG/DTA). The experimental results confirm a uniform deposition of an adherent layer. In this paper we present a part of the characteristics of sucrose thin films deposited on glass in medium vacuum conditions, as a part of a culture medium for osteoblast cells. Osteoblast cells were used to determine proliferation, viability, and cytotoxicity interactions with sucrose powder and sucrose thin films. The osteoblast cells have been provided from the American Type Culture Collection (ATCC) Centre. The outcome of this study demonstrated the effectiveness of sucrose thin films as a possible nontoxic agent for biomedical applications

Enhancement of Silymarin Anti-fibrotic Effects by Complexation With Hydroxypropyl (HPBCD) and Randomly Methylated (RAMEB) β-Cyclodextrins in a Mouse Model of Liver Fibrosis

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