101 research outputs found

    Ganoderma lucidum Extracts Inhibited Leukemia WEHI-3 Cells in BALB/c Mice and Promoted an Immune Response in Vivo

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    [[abstract]]Ganoderma lucidum (G. lucidum) is a medicinal mushroom having biological effects such as immuno-modulation and anti-tumor actions. In China and many other Asian countries, G. lucidum is used as a folk remedy to promote health and longevity. Although many studies have shown that G. lucidum modulates the immune system, including, for example, antigen-presenting cells, natural killer (NK) cells, and the T and B lymphocytes, the effects of G. lucidum on the WEHI-3 leukemic BALB/c mice are unclear. We attempted to determine whether G. lucidum would promote immune responses in BALB/c mice injected with WEHI-3 leukemia cells. The effects of G. lucidum on the survival rate of WEHI-3 leukemia cells injected into BALB/c mice were examined. It increased the percentages of CD3 and CD19, but decreased, the percentages of Mac-3 and CD11b markers, suggesting that differentiation of the precursor of T and B cells was promoted but macrophages were inhibited. It decreased the weight of spleens as compared with control mice. It also promoted phagocytosis by macrophage from peripheral blood mononuclear cell (PBMC) and it also promoted natural killer cell activity. It decreased the percentage of leukemia cells in the spleens of mice before they were injected with WEHI-3 cells. Apparently, G. lucidum affects murine leukemia WEHI-3 cells in vivo

    Gandoderma lucidum Extract Promotes Immune Responses in Normal BALB/c Mice In Vivo

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    [[abstract]]Enhanced fruit and vegetable consumption is closely related to reduced cancer incidence as shown in epidemiological studies. Ganoderma lucidum, one of the most well-known traditional Chinese medicines, has been demonstrated to have pharmacological activities and antitumor effects, in Asian populations. However, the promotion of immune responses in normal BALB/c mice is unclear. In the present study, we investigated the immune responses of BALB/c mice after treatment with G. lucidum extract in vivo. The results demonstrated that G. lucidum extract was able to promote the proliferation of splenocytes under Concanavalin A or lipopolysaccharide stimulation. Compared with the control group, phagocytosis of macrophage was significantly enhanced by intraperitoneal administration of G. lucidum extract at both 3 and 6 mg/kg. Compared with the control group, natural killer cell activity was significantly enhanced by intraperitoneal administration of G. lucidum extract (6 mg/kg). Results of cytometric bead array and flow cytometry indicated that the expressions of interleukin-6 and interferon-gamma also increased (p<0.001) by treatment with G. lucidum extract (3 and 6 mg/kg). In conclusion, the findings of this study implied that G. lucidum extract was able to effectively promote immune responses in BALB/c mice

    Impaired dermal wound healing in discoidin domain receptor 2-deficient mice associated with defective extracellular matrix remodeling

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    Background The wounding response relies on tightly regulated crosstalk between recruited fibroblasts and the collagenous extracellular matrix (ECM). Discoidin domain receptor 2 (DDR2) is a tyrosine kinase receptor for fibrillar collagen expressed during pathologic scarring, for example wound healing, arthritis and cancer. We have previously shown that DDR2 phosphorylation drives key wounding responses in skin fibroblasts including proliferation, chemotactic migration and secretion of both metalloproteinases and fibrillar collagen. In this study we compared healing of cutaneous wounds in DDR2+/+ and DDR2-/- mice and analyzed specific fibroblast responses. Results Cutaneous wound healing was significantly delayed in DDR2-/- mice compared with DDR2+/+ animals. Reduced Ξ±-smooth muscle actin (Ξ±SMA) expression and matrix metalloproteinase 2 (MMP2) activity in the DDR2-/- wound extracts indicated defective recruitment of skin fibroblasts. DDR2-/- wounds showed decreased tensile strength during healing, which correlated with a significant reduction in collagen content and defective collagen crosslinking. Non-wounded skin in DDR2-/- mice expressed less mRNA of the crosslinking enzymes lysyl oxidase (LOX), lysyl hydroxylase1 (LH1) and matricellular 'secreted protein, acidic and rich in cysteine' (SPARC; also known as osteonectin). Skin fibroblasts isolated from DDR2-/- mice displayed altered mRNA expression of a cluster of collagens, proteoglycans, integrins and MMPs that have been previously correlated with DDR2 expression, and reduced LOX, LH1 and SPARC mRNA levels and proteins. Stable reconstitution of wild-type DDR2 by retroviral infection restored LOX, LH1 and SPARC mRNA and protein levels in DDR2-/- fibroblasts. Contraction of collagen gels was reduced in DDR2-/- fibroblasts, accompanied by significantly reduced phosphorylated SrcY418. Inhibition of either LOX activity by Ξ²-aminoproprionitrile or MMP activity by N-[(2R)-2-(hydroxamido carbonylmethyl)-4-methylpentanoyl]-l-tryptophan methylamide (GM6001) reduced collagen gel contraction by skin fibroblasts after DDR2 induction with soluble collagen type I. Conclusions DDR2 contributes to skin fibroblast responses during tissue injury. Defective synthesis of collagen type I, crosslinking molecules and MMP2 predispose DDR2-/- mice to defective dermal wounding

    Microwave-Assisted Synthesis of Titania Nanocubes, Nanospheres and Nanorods for Photocatalytic Dye Degradation

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    TiO2nanostructures with fascinating morphologies like cubes, spheres, and rods were synthesized by a simple microwave irradiation technique. Tuning of different morphologies was achieved by changing the pH and the nature of the medium or the precipitating agent. As-synthesized titania nanostructures were characterized by X-ray diffraction (XRD), UV–visible spectroscopy, infrared spectroscopy (IR), BET surface area, photoluminescence (PL), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and atomic force microscopy (AFM) techniques. Photocatalytic dye degradation studies were conducted using methylene blue under ultraviolet light irradiation. Dye degradation ability for nanocubes was found to be superior to the spheres and the rods and can be attributed to the observed high surface area of nanocubes. As-synthesized titania nanostructures have shown higher photocatalytic activity than the commercial photocatalyst Degussa P25 TiO2

    Dengue Virus Targets the Adaptor Protein MITA to Subvert Host Innate Immunity

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    Dengue is one of the most important arboviral diseases caused by infection of four serotypes of dengue virus (DEN). We found that activation of interferon regulatory factor 3 (IRF3) triggered by viral infection and by foreign DNA and RNA stimulation was blocked by DEN-encoded NS2B3 through a protease-dependent mechanism. The key adaptor protein in type I interferon pathway, human mediator of IRF3 activation (MITA) but not the murine homologue MPYS, was cleaved in cells infected with DEN-1 or DEN-2 and with expression of the enzymatically active protease NS2B3. The cleavage site of MITA was mapped to LRR↓96G and the function of MITA was suppressed by dengue protease. DEN replication was reduced with overexpression of MPYS but not with MITA, while DEN replication was enhanced by MPYS knockdown, indicating an antiviral role of MITA/MPYS against DEN infection. The involvement of MITA in DEN-triggered innate immune response was evidenced by reduction of IRF3 activation and IFN induction in cells with MITA knockdown upon DEN-2 infection. NS2B3 physically interacted with MITA, and the interaction and cleavage of MITA could be further enhanced by poly(dA:dT) stimulation. Thus, we identified MITA as a novel host target of DEN protease and provide the molecular mechanism of how DEN subverts the host innate immunity

    Global Analyses of Small Interfering RNAs Derived from Bamboo mosaic virus and Its Associated Satellite RNAs in Different Plants

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    Background: Satellite RNAs (satRNAs), virus parasites, are exclusively associated with plant virus infection and have attracted much interest over the last 3 decades. Upon virus infection, virus-specific small interfering RNAs (vsiRNAs) are produced by dicer-like (DCL) endoribonucleases for anti-viral defense. The composition of vsiRNAs has been studied extensively; however, studies of satRNA-derived siRNAs (satsiRNAs) or siRNA profiles after satRNA co-infection are limited. Here, we report on the small RNA profiles associated with infection with Bamboo mosaic virus (BaMV) and its two satellite RNAs (satBaMVs) in Nicotiana benthamiana and Arabidopsis thaliana. Methodology/Principal Findings: Leaves of N. benthamiana or A. thaliana inoculated with water, BaMV alone or coinoculated with interfering or noninterfering satBaMV were collected for RNA extraction, then large-scale Solexa sequencing. Up to about 20% of total siRNAs as BaMV-specific siRNAs were accumulated in highly susceptible N. benthamiana leaves inoculated with BaMV alone or co-inoculated with noninterfering satBaMV; however, only about 0.1% of vsiRNAs were produced in plants co-infected with interfering satBaMV. The abundant region of siRNA distribution along BaMV and satBaMV genomes differed by host but not by co-infection with satBaMV. Most of the BaMV and satBaMV siRNAs were 21 or 22 nt, of both (+) and (-) polarities; however, a higher proportion of 22-nt BaMV and satBaMV siRNAs were generated in N. benthamiana than in A. thaliana. Furthermore, the proportion of non-viral 24-nt siRNAs was greatly increased in N. benthamiana after virus infection. Conclusions/Significance: The overall composition of vsiRNAs and satsiRNAs in the infected plants reflect the combined action of virus, satRNA and different DCLs in host plants. Our findings suggest that the structure and/or sequence demands of various DCLs in different hosts may result in differential susceptibility to the same virus. DCL2 producing 24-nt siRNAs under biotic stresses may play a vital role in the antiviral mechanism in N. benthamiana
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