43 research outputs found

    The impact of nanoparticles on the proteome of cultured human cells

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    Doctor ScientiaeLiving organisms are constantly being exposed to nanoparticles (NPs) in the environment via air, water, soil. Routes of exposure are usually in the form of industrial, occupational exposure, as well as therapeutic applications. This exposure could result in toxicity with potential harmful effects. The toxicity of nanoparticles depends on various factors such as surface interaction, shape, size, composition, aggregation and interaction with various cellular components. Nanotoxicity refers to the possible harmful effects of environmentally generated and man-made nanoparticles on biological and environmental system. Assessing potential toxicity is vital for the probable use and safety of nanoparticles as well as understanding the routes of entry into organisms and their mechanism of action. Proteomics is a developing field of science that is being explored to understand protein composition, structure and interaction at the cellular level. This helps in detecting the presence, quantity, alteration and regulation of proteins within the biological system. The proteome analysis brings an additional information as it enables measurement of wholeprotein (enzyme) expression levels, facilitating the construction of metabolic pathways and biomarker discovery for early disease diagnosis. Essentially, proteomic analysis reveals the consequence of stress on metabolic pathways necessary to maintain the energy homeostasis within the cells

    Inflammatory Bowel Disease

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    This book is an overview of invited contributions on recent data of inflammatory bowel diseases. The first part of the book covers topics related to the ethiopathogenesis of inflammatory bowel diseases including the environmental, genetic factors and immunological alternations. The next chapters deal with present day management of disease including radiological diagnosis and surgical treatment, which consider the advances of most up-to-date radiological methodology including MRI techniques and the role of surgical procedures in the therapy. The final part presents medical therapy and its future directions. These chapters discuss natural products exerting anti-inflammatory and anti-tumour effects, methods of colon targeting drug delivery systems including polysaccharides, peptides and nanoparticules; as well as the potential risks of nanotechnology based food materials

    Defining the mechanistic toxicity of metal oxide nanoparticles in vitro, under physiologically relevant oxygen concentrations

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    Metal oxide nanoparticles (MONPs) are intended for use in numerous consumer applications, leading to inevitable human exposure. Previous work conducted in hyperoxic cell culture conditions (21% O2, 5% CO2) with nanoparticles (NPs) has proven the ability of some material types to induce genotoxicity and inflammatoxicity. Alteration in intracellular calcium [i(Ca2+)] signalling is involved in facilitating toxicity through the alteration of signal-transduction pathways, but there is less understanding of the impact of NPs exposure upon changes in such signalling pathways. Furthermore, whilst human cells cultured in ambient air may induce a particular toxicity profile, this may not be the same under the physiologic oxygen conditions experienced in the human body. Therefore, the aim of this study was to assess the impact of anatase TiO2 (NM-102), Rutile TiO2 (NM-104) and dextran coated superparamagnetic Fe3O4 (dSPIONs) upon monocytes (THP-1), macrophages (dTHP-1) and hepatocarcinoma (HepG2) cells in both an in vivo-resembling physioxia environment (5%O2, 5%CO2) and hyperoxic cell culture conditions (21%O2, 5%CO2). Their impact on i(Ca2+) homeostasis and how it relates to their potential genotoxic potential was also evaluated.Due to the importance of different physicochemical characteristics for the facilitation of toxicity, all MONPs were characterized. MONPs hydrodynamic diameter (HD) and ζ-potential (ζ) in PBS were identified using dynamic light scattering: NM-102: HD=391.9nm, ζ =7.1±2.0mV; NM-104: HD=255nm, ζ=14.6 +/- 2.1mV; dSPIONs: HD=88.6nm, ζ =10.4±1.3mV. The possible toxic effect of NPs depends on their concentration and duration of their interaction with cells. Therefore, following 24h exposure to dSPIONs (0-100µg/ml), concentration-dependent and cell-type-dependent (dTHP1>THP-1>HepG2) significant increases in NP-cellular interaction were observed, which was significantly greater in the physioxic culture environment. Concurrent, significant loss of dSPION-associated cell proliferation (evaluated using relative population doubling) in all cell lines and significant increases in DNA damage was also identified in HepG2 cells (using the cytokinesis block micronucleus assay), albeit only in physioxia. Exposure to ≥10ug/ml NM-102 and NM-104 resulted in significant, two-fold increases in micronuclei formation in HepG2 in both environments. All MONPs induced a significant increase in tumour necrosis factor-α and interleukin-8 secretion in all cell lines and oxygen culture environments. Increase in the production of the chemokines was correlated with the observed HepG2 cell genotoxicity. In all cell lines and cell culture environments, treatment for up to 5h with NM-102 or dSPIONs triggered cell type specific increases in i(Ca2+) that correlated with the reduction of cellular antioxidant glutathione (measured after 5h treatment with all the MONPs). After pre-treatment of the cell lines with antioxidant trollox in all cell culture environments i(Ca2+) appeared to be increased independently from the change of cellular redox status. Environment-specific biological interaction and impacts with regard to NP uptake, genotoxic effects, and consequence on cellular signaling mechanisms were only observed with dSPIONs in a physioxic culture environment, while NM-102 and NM-104 induced similar effects in both environments. The results presented in this study allow the conclusion that the environmental oxygen content has an impact on the NP toxicity profiles although it is NP dependent

    Modulation of macrophage and epithelial cell immune defences by probiotic bacteria: immune stimulation versus suppression

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    Abstract Probiotic bacteria are live organisms, if consumed in adequate amounts might confer health benefits. These bacteria, such as Lactic acid bacteria (LAB), include a number of strains that have specific health promoting activi-ties, attributed to their immunomodulatory and anti-inflammatory properties. Gut mucosal macrophage subsets play a fundamental role in driving muco-sal immune responses. These include, tolerance, associated with an M2-, regulatory macrophage phenotype and inflammatory activation with an M1-like phenotype. The cross-link between mucosal tolerance and inflammatory cytokine suppression, and augmentation of IL-10 production in the gut relate to endotoxin tolerance. Endotoxin tolerance is a context; it could present an example for cell drive through a hypo-responsive state. An example is mu-cosal inflammatory pathologies, such as Crohn’s disease. When tolerance is broken, causing the destruction of gut mucosal tissue. This is where the macrophage phenotype, has been transformed from a regulatory M2- to an inflammatory M1-like phenotype. This is seen as a reaction to both, patho-genic and commensal bacteria. This investigation was aimed at assessing the activities of live probiotic bacteria; Lactobacillus salivarius strain MS13 and Lactobacillus plantarum strain C28 in the immunomodulation of macro-phage subsets in health, inflammation, and endotoxin tolerance. M1- and M2-like macrophages were generated in vitro from the THP-1 monocyte cell line by differentiation with PMA and Vitamin D3, respectively. Additionally, differentiated epithelial cells (Caco-2) were obtained by long term culturing for 21 days. The role of Lactobacillus strains C28 and MS13 to modulate epi-thelial barrier integrity and macrophage-epithelial cell inflammation was in-vestigated. TNFα, IL-1β, IL-18, IL-23, IL-12, IL-6, IL-8, and IL-10 were quanti-fied by ELISA and RT-PCR, whereas TLR-2, TLR-4, Tollip, SOCS3, STAT3 and TRAIL by RT-PCR. This study revealed that, first, live C28 and MS13 stimulated the proinflammatory cytokine by M2-like macrophages as well as the anti-inflammatory cytokine in a homeostatic status; whereas in an in-flammatory environment, C28 and MS13 differentially upregulated TNFα and IL-1β by M1 and M2-like macrophages induced by E.coli K12-LPS. Both strains downregulated K12-LPS induced IL-10 by M2-like macrophages. The response of stimulated M1 and M2 macrophages to C28 and MS13, was to differentially induce the gene expression of TLR-2, TLR-4, Tollip, NLRP3, SOCS-3, STAT3 and TRAIL. Second, the repeat-stimulation/tolerisation of M1 and M2 macrophages by live probiotic bacteria revealed, TNFα, IL-1β, IL-23, IL-18, IL-6 and IL-10 were upregulated in M1-like macrophages by C28, whereas MS13 upregulated TNFα, IL-1β, IL-18, and downregulated IL-12, IL-6, and IL-10. On the other hand, the tolerisation of M2-like macrophages by C28 and MS13 resulted in the downregulation of TNFα and IL-12p35 and upregulation of IL-1β, IL-18, IL-23, IL-12, IL-6, and IL-10. These findings were linked with the differential macrophage subset upregulation of TLR-4, NLRP3, STAT-3 and TRAIL gene expression. On the other hand, TLR-2, Tol-lip and SOCS-3 were downregulated in tolerised macrophage subsets by C28 and MS13. Furthermore, the role of lactobacilli strains C28 and MS13 in the modulation of endotoxin tolerance was to; upregulate TNF-α, IL-18, IL-23 and IL-10 by M1 and M2-like macrophages. This investigation also focused on the induction of the zona-occludin-1 (Zo-1), human β defensin-2 (hBD-2), and cytokine production IL-8 by Caco-2 cells. Trans epithelial electrical re-sistance (TEER) and RT-PCR measured the main cytokines studied pro-duced by Caco-2, were IL-8, also the epithelial barrier function. Live probiotic C28 and MS13 suppressed the production of IL-8 (in the presence or ab-sence TNFα and IL-1β). Moreover, in the co-culture of Caco-2 with macro-phage subsets, MS13 enhanced the expression of hBD-2 and ZO-1. These findings allow for the better understanding of live probiotic roles on macro-phage subsets functions and endotoxin tolerisation mechanisms, which may be beneficial for the development of in vivo models of probiotic bacteria and therapeutic targeting of inflammatory bowel disease.Iraqi Cultural attach

    Synthesis and Characterization of American Ginseng Polysaccharides Nanoparticles

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    This project was concerned with the synthesis of nanoparticles (NPs) by microfluidics from bulk ginseng polysaccharides (PS) isolated from American ginseng to design a new delivery system to improve the bioavailability of PS. Physicochemical analyses showed products of nanosizing as unimodal spheres with a diameter of ~19 nm. Pharmacological characterization studies in vitro of these nanoparticles of PS (NPPS) have demonstrated heightened immunostimulatory activity, and enhanced penetration across skin cell monolayer, which could be considered as evidence of increased bioavailability. Studies using PS sub-fractions with different molecular weights for NPPS synthesis showed that molecular weights is one of the parameters that influence the quality of NPPS. Mechanistic study revealed that NPPS acted like PS in targeting the Toll-like receptor-signalling pathway in mediating the immune-stimulatory effect. This nanotechnology may be applied to produce innovative ginseng polysaccharide-based nutraceuticals with improved bioavailability

    Natural Products and Disease Prevention, Relief and Treatment

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    The consumption of fruits, vegetables, herbs, spices, etc., is thought to be associated with reduced risk for many human diseases, including cancers. Recently, significant advances have been made in evaluating the efficacy of natural products (compounds from natural sources) against human diseases. The purpose of this Special Issue, “Natural Products and Disease Prevention, Relief and Treatment", was to collect manuscripts concerning natural products for treating human diseases. Consequently, we have collected several high-quality manuscripts that focus on the molecular mechanisms of natural products, including their anti-inflammatory, antioxidative, neuroprotective, cardioprotective, antifibrotic, and anticancer effects, as well as other health beneficial effects across a wide range of human diseases. Overall, this Special Issue is an excellent source for information on promising natural products for future preclinical and clinical research into multiple diseases

    Phytochemical Omics in Medicinal Plants

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    Medicinal plants are used to treat diseases and provide health benefits, and their applications are increasing around the world. A huge array of phytochemicals have been identified from medicinal plants, belonging to carotenoids, flavonoids, lignans, and phenolic acids, and so on, with a wide range of biological activities. In order to explore our knowledge of phytochemicals with the assistance of modern molecular tools and high-throughput technologies, this book collects recent innovative original research and review articles on subtopics of mechanistic insights into bioactivities, treatment of diseases, profiling, extraction and identification, and biotechnology

    Removal of antagonistic spindle forces can rescue metaphase spindle length and reduce chromosome segregation defects

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    Regular Abstracts - Tuesday Poster Presentations: no. 1925Metaphase describes a phase of mitosis where chromosomes are attached and oriented on the bipolar spindle for subsequent segregation at anaphase. In diverse cell types, the metaphase spindle is maintained at a relatively constant length. Metaphase spindle length is proposed to be regulated by a balance of pushing and pulling forces generated by distinct sets of spindle microtubules and their interactions with motors and microtubule-associated proteins (MAPs). Spindle length appears important for chromosome segregation fidelity, as cells with shorter or longer than normal metaphase spindles, generated through deletion or inhibition of individual mitotic motors or MAPs, showed chromosome segregation defects. To test the force balance model of spindle length control and its effect on chromosome segregation, we applied fast microfluidic temperature-control with live-cell imaging to monitor the effect of switching off different combinations of antagonistic forces in the fission yeast metaphase spindle. We show that spindle midzone proteins kinesin-5 cut7p and microtubule bundler ase1p contribute to outward pushing forces, and spindle kinetochore proteins kinesin-8 klp5/6p and dam1p contribute to inward pulling forces. Removing these proteins individually led to aberrant metaphase spindle length and chromosome segregation defects. Removing these proteins in antagonistic combination rescued the defective spindle length and, in some combinations, also partially rescued chromosome segregation defects. Our results stress the importance of proper chromosome-to-microtubule attachment over spindle length regulation for proper chromosome segregation.postprin

    Psr1p interacts with SUN/sad1p and EB1/mal3p to establish the bipolar spindle

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    Regular Abstracts - Sunday Poster Presentations: no. 382During mitosis, interpolar microtubules from two spindle pole bodies (SPBs) interdigitate to create an antiparallel microtubule array for accommodating numerous regulatory proteins. Among these proteins, the kinesin-5 cut7p/Eg5 is the key player responsible for sliding apart antiparallel microtubules and thus helps in establishing the bipolar spindle. At the onset of mitosis, two SPBs are adjacent to one another with most microtubules running nearly parallel toward the nuclear envelope, creating an unfavorable microtubule configuration for the kinesin-5 kinesins. Therefore, how the cell organizes the antiparallel microtubule array in the first place at mitotic onset remains enigmatic. Here, we show that a novel protein psrp1p localizes to the SPB and plays a key role in organizing the antiparallel microtubule array. The absence of psr1+ leads to a transient monopolar spindle and massive chromosome loss. Further functional characterization demonstrates that psr1p is recruited to the SPB through interaction with the conserved SUN protein sad1p and that psr1p physically interacts with the conserved microtubule plus tip protein mal3p/EB1. These results suggest a model that psr1p serves as a linking protein between sad1p/SUN and mal3p/EB1 to allow microtubule plus ends to be coupled to the SPBs for organization of an antiparallel microtubule array. Thus, we conclude that psr1p is involved in organizing the antiparallel microtubule array in the first place at mitosis onset by interaction with SUN/sad1p and EB1/mal3p, thereby establishing the bipolar spindle.postprin
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