Proteomic analysis for inhibitory effect of chitosan oligosaccharides on 3T3-L1 adipocyte differentiation

In the present study, we performed a differential proteomic analysis using 2-DE combined with MS to clarify the molecular mechanism for the suppressive effect of chitosan oligosaccharides (CO) during differentiation of adipocyte 3T3-L1. Cell differentiation was significantly inhibited by CO at the concentration of 4 mg/mL. Protein mapping of adipocyte homogenates by 2-DE revealed that numerous protein spots were differentially altered in response to CO treatment. Out of 50 identified proteins showing significant alterations, six were up-regulated and 44 were down-regulated by CO treatment in comparison to control mature adipocytes. Among them, most of the proteins are associated with lipid metabolism, cytoskeleton, and redox regulation, in which the levels of farnesyl diphosphate synthetase (FDS), dedicator of cytokinesis 9 (DOCK9), and chloride intracellular channel 1 (CLIC1) were significantly reduced (>two-fold) with CO treatment. These results have not previously been examined in the context of adipogenesis, and thus can be used as novel biomarkers. Taken together with immunoblot analysis, it was concluded that the inhibitory effect of CO on adipocyte differentiation was mediated by C/EBPalpha and PPARgamma pathway through significant downregulations of important adipogenic molecules such as fatty acid binding protein and glucose transporter 4.     

Cancer chemoprevention: inhibitory effect of soybeans fermented with basidiomycetes on 7,12-dimethylbenz[a]anthracene/12-O-tetradecanoylphorbol-13-acetate-induced mouse skin carcinogenesis

In a two-stage skin carcinogenesis model, mice initiated with 7,12-dimethylbenz[a]anthracene and promoted with 12-O-tetradecanoylphorbol-13-acetate (TPA) for 12 weeks developed an average of 15.8 skin tumours per mouse with 100% tumour incidence. Topical application of polysaccharides from soybeans fermented with either Phellinus igniarius or Agrocybe cylindracea together with TPA twice weekly for 12 weeks inhibited the number of skin tumours per mouse by 70 or 88%, respectively, and the percentage of mice with tumours was lowered by 70 or 30%, respectively.     

Antigen-specific modulation of an immune response by in vivo administration of soluble MHC class I tetramers

Soluble MHC/peptide tetramers that can directly bind the TCR allow the direct visualization and quantitation of Ag-specific T cells in vitro and in vivo. We used HY-D(b) tetramers to assess the numbers of HY-reactive CD8+ T cells in HYTCR-transgenic mice and in naive, wild-type C57BL/6 (B6) mice. As expected, tetramer staining showed the majority of T cells were male-specific CD8+ T cells in female HY-TCR mice. Staining of B6 mice showed a small population of male-specific CD8+ T cells in female mice. The effect of administration of soluble MHC class I tetramers on CD8+ T cell activation in vivo was unknown. Injection of HY-D(b) tetramer in vivo effectively primed female mice for a more rapid proliferative response to both HY peptide and male splenocytes. Furthermore, wild-type B6 female mice injected with a single dose of HY-D(b) tetramer rejected B6 male skin grafts more rapidly than female littermates treated with irrelevant tetramer. In contrast, multiple doses of HY-D(b) tetramer did not further decrease graft survival. Rather, female B6 mice injected with multiple doses of HY-D(b) tetramer rejected male skin grafts more slowly than mice primed with a single injection of tetramer or irradiated male spleen cells, suggesting clonal exhaustion or anergy. Our data highlight the ability of soluble MHC tetramers to identify scarce alloreactive T cell populations and the use of such tetramers to directly modulate an Ag-specific T cell response in vivo.     

Eutrophication,agriculture and water level control shift aquatic plant communities from floating-leaved to submerged macrophytes in Lake Chini,Malaysia

In this study we: (1) present a quantitative spatial analysis of the macrophyte communities in Lake Chini with a focus on the biogeographical distributions of the native Nelumbo nucifera and the invasive Cabomba furcata; (2) examine the environmental changes that affect plant community composition; and (3) outline a conceptual model of the variation of ecological processes that shape the macrophyte communities. Plant species cover, biomass of C. furcata and N. nucifera, and water quality and environmental variables were measured before and after monsoonal floods in September 2009 and April 2010. Permutational multivariate analysis was used to examine the significance of the invasion of C. furcata at different spatial scales. Relationships between plant species cover and environmental variables before and after flooding were examined using principal coordinates analysis and non-parametric multivariate multiple regressions. Our findings suggest that (1) Variation in plant communities was significant at the lake scale and the distribution of plant species changed after annual floods. (2) Invasion by C. furcata significantly affected the overall plant community composition. (3) C. furcata biomass increased after the monsoonal season, which indicates that C. furcata is adapted to flooding events and that it is becoming increasingly abundant. (4) In addition to the strong monsoonal effect, total depth, nutrient concentration, and sediment type were important environmental variables that significantly affected plant community composition. The macrophyte community in Lake Chini is highly dynamic. The spatial and temporal plant community dynamics are associated with flood regime, water quality, and substrate. Human-induced changes in these parameters are likely shifting the macrophyte dominance from floating-leaved to submerged species.     

Bone morphogenetic protein-4 induced by NDRG2 expression inhibits MMP-9 activity in breast cancer cells

In the current study, we examined the function of N-myc downstream-regulated gene 2 (NDRG2) expression in breast cancer cells, especially focusing on the role of bone morphogenetic protein-4 (BMP-4) induced by NDRG2. NDRG2 expression in MDA-MB-231 cells inhibited the mRNA expression of several matrix metalloproteinases (MMPs) and the gelatinolytic activity of MMP-9. Interestingly, a specific induction of active BMP-4 was exclusively observed in MDA-MB-231-NDRG2 cells but not in MDA-MB-231-mock cells. Neutralization of BMP-4 in MDA-MB-231-NDRG2 cells resulted in the rescue of MMP-9 mRNA expression and migration capacity. In addition, treatment with recombinant BMP-4 dramatically suppressed MMP-9 mRNA expression, gelatinolytic MMP-9 activity, migration, and invasion capacity both in MDA-MB-231 and PMA-treated MCF-7 cells. Collectively, our data show that BMP-4 induced by NDRG2 expression inhibits the metastatic potential of breast cancer cells, especially via suppression of MMP-9 activity.     

Comparing the phenomenological qualities of stimulus-independent thought,stimulus-dependent thought and dreams using experience sampling

Humans spend a considerable portion of their lives engaged in ‘stimulus-independent thoughts'' (SIT), or mental activity that occurs independently of input from the immediate external environment. Although such SITs are, by definition, different from thoughts that are driven by stimuli in one''s external environment (i.e. stimulus-dependent thoughts; SDTs), at times, the phenomenology of these two types of thought appears to be deceptively similar. But how similar are they? We address this question by comparing the content of two types of SIT (dreaming and waking SITs) with the content of SDTs. In this 7 day, smartphone-based experience-sampling procedure, participants were intermittently probed during the day and night to indicate whether their current thoughts were stimulus dependent or stimulus independent. They then responded to content-based items indexing the qualitative aspects of their experience (e.g. My thoughts were jumping from topic to topic). Results indicate substantial distinctiveness between these three types of thought: significant differences between at least two of the three mental states were found across every measured variable. Implications are discussed.This article is part of the theme issue ‘Offline perception: voluntary and spontaneous perceptual experiences without matching external stimulation’.     

Fertiliser drawn forward osmosis desalination: the concept, performance and limitations for fertigation

With the world??s population growing rapidly, pressure is increasing on the limited fresh water resources. Membrane technology could play a vital role in solving the water scarcity issues through alternative sources such as saline water sources and wastewater reclamation. The current generation of membrane technologies, particularly reverse osmosis (RO), has significantly improved in performance. However, RO desalination is still energy intensive and any effort to improve energy efficiency increases total cost of the product water. Since energy, environment and climate change issues are all inter-related, desalination for large-scale irrigation requires new novel technologies that address the energy issues. Forward osmosis (FO) is an emerging membrane technology. However, FO desalination for potable water is still a challenge because, recovery and regeneration of draw solutes require additional processes and energy. This article focuses on the application of FO desalination for non-potable irrigation where maximum water is required. In this concept of fertiliser drawn FO (FDFO) desalination, fertilisers are used as draw solutions (DS). The diluted draw solution after desalination can be directly applied for fertigation without the need for recovery and regeneration of DS. FDFO desalination can make irrigation water available at comparatively lower energy than the current desalination technologies. As a low energy technology, FDFO can be easily powered by renewable energy sources and therefore suitable for inland and remote applications. This article outlines the concept of FDFO desalination and critically evaluates the scope and limitations of this technology for fertigation, including suggestions on options to overcome some of these limitations.     

The response to oxidative stress induced by magnesium deficiency in kidney bean plants

To understand the plant response to oxidative stresses, we studied the influence of magnesium (Mg⁺⁺) deficiency on the formation of hydrogen peroxide (H₂O₂), malondialdehyde (MDA), and protease activity in kidney bean plants. The expression pattern of proteins under Mg⁺⁺ deficiency also was examined via two-dimensional electrophoresis. The formation of H₂O₂ and MDA increased in the primary leaves of plants grown in a nutrient solution deficient in Mg⁺⁺. Protease activity in Mg⁺⁺-deficient plants was also higher than in those grown with sufficient Mg⁺⁺. The expression pattern of the proteins showed that 25 new proteins were generated and 64 proteins disappeared under Mg⁺⁺-deficient conditions. Therefore, a deficiency in Mg⁺⁺ may cause oxidative stress and a change in protein expression. Some of these proteins may be related to the oxidative stress induced by Mg⁺⁺ deficiency.     

Nano-mechanical measurements of protein-DNA interactions with a silicon nitride pulley

Proteins adhere to DNA at locations and with strengths that depend on the protein conformation, the underlying DNA sequence and the ionic content of the solution. A facile technique to probe the positions and strengths of protein-DNA binding would aid in understanding these important interactions. Here, we describe a ‘DNA pulley’ for position-resolved nano-mechanical measurements of protein-DNA interactions. A molecule of λ DNA is tethered by one end to a glass surface, and by the other end to a magnetic bead. The DNA is stretched horizontally by a magnet, and a nanoscale knife made of silicon nitride is manipulated to contact, bend and scan along the DNA. The mechanical profile of the DNA at the contact with the knife is probed via nanometer-precision optical tracking of the magnetic bead. This system enables detection of protein bumps on the DNA and localization of their binding sites. We study theoretically the technical requirements to detect mechanical heterogeneities in the DNA itself.