Docosahexaenoic Acid Induces Apoptosis in MCF-7 Cells In Vitro and In Vivo via Reactive Oxygen Species Formation and Caspase 8 Activation

BACKGROUND: The present study sought to further investigate the in vitro and in vivo anticancer effects of a representative omega-3 fatty acid, docosahexaenoic acid (DHA), with a focus on assessing the induction of oxidative stress and apoptosis as an important mechanism for its anticancer actions. METHODOLOGY/PRINCIPAL FINDINGS: In vitro studies showed that DHA strongly reduces the viability and DNA synthesis of MCF-7 human breast cancer cells in culture, and also promotes cell death via apoptosis. Mechanistically, accumulation of reactive oxygen species and activation of caspase 8 contribute critically to the induction of apoptotic cell death. Co-presence of antioxidants or selective inhibition or knockdown of caspase 8 each effectively abrogates the cytotoxic effect of DHA. Using athymic nude mice as an in vivo model, we found that feeding animals the 5% fish oil-supplemented diet for 6 weeks significantly reduces the growth of MCF-7 human breast cancer cells in vivo through inhibition of cancer cell proliferation as well as promotion of cell death. Using 3-nitrotyrosine as a parameter, we confirmed that the fish oil-supplemented diet significantly increases oxidative stress in tumor cells in vivo. Analysis of fatty acid content in plasma and tissues showed that feeding animals a 5% fish oil diet increases the levels of DHA and eicosapentaenoic acid in both normal and tumorous mammary tissues by 329% and 300%, respectively. CONCLUSIONS/SIGNIFICANCE: DHA can strongly induce apoptosis in human MCF-7 breast cancer cells both in vitro and in vivo. The induction of apoptosis in these cells is selectively mediated via caspase 8 activation. These observations call for further studies to assess the effectiveness of fish oil as a dietary supplement in the prevention and treatment of human breast cancer

Deletion of DOCK2, a regulator of the actin cytoskeleton in lymphocytes, suppresses cardiac allograft rejection

Allograft rejection is induced by graft tissue infiltration of alloreactive T cells that are activated mainly in secondary lymphoid organs of the host. DOCK2 plays a critical role in lymphocyte homing and immunological synapse formation by regulating the actin cytoskeleton, yet its role in the in vivo immune response remains unknown. We show here that DOCK2 deficiency enables long-term survival of cardiac allografts across a complete mismatch of the major histocompatibility complex molecules. In DOCK2-deficient mice, alloreactivity and allocytotoxicity were suppressed significantly even after in vivo priming with alloantigens, which resulted in reduced intragraft expression of effector molecules, such as interferon-γ, granzyme B, and perforin. This is mediated, at least in part, by preventing potentially alloreactive T cells from recruiting into secondary lymphoid organs. In addition, we found that DOCK2 is critical for CD28-mediated Rac activation and is required for the full activation of alloreactive T cells. Although DOCK2-deficient, alloreactive T cells were activated in vitro in the presence of exogenous interleukin-2, these T cells, when transferred adoptively, failed to infiltrate into the allografts that were transplanted into RAG1-deficient mice. Thus, DOCK2 deficiency attenuates allograft rejection by simultaneously suppressing multiple and key processes. We propose that DOCK2 could be a novel molecular target for controlling transplant rejection

Building a discriminatively ordered subspace on the generating matrix to classify high-dimensional spectral data

Soft independent modelling of class analogy (SIMCA) is a widely-used subspace method for spectral data classification. However, since the class subspaces are built independently in SIMCA, the discriminative between-class information is neglected. An appealing remedy is to first project the original data to a more discriminative subspace. For this, generalised difference subspace (GDS) that explores the information between class subspaces in the generating matrix can be a strong candidate. However, due to the difference between a class subspace (of infinite scale) and a class (of finite scale), the eigenvectors selected by GDS may not also be discriminative for classifying samples of classes. Therefore in this paper, we propose a discriminatively ordered subspace (DOS): different from GDS, our DOS selects the eigenvectors with high discriminative ability between classes rather than between class subspaces. The experiments on three real spectral datasets demonstrate that applying DOS before SIMCA outperforms its counterparts

Optical Properties of (162173) 1999 JU3: In Preparation for the JAXA Hayabusa 2 Sample Return Mission

We investigated the magnitude-phase relation of (162173) 1999 JU3, a target asteroid for the JAXA Hayabusa 2 sample return mission. We initially employed the international Astronomical Union's H-G formalism but found that it fits less well using a single set of parameters. To improve the inadequate fit, we employed two photometric functions, the Shevchenko and Hapke functions. With the Shevchenko function, we found that the magnitude-phase relation exhibits linear behavior in a wide phase angle range (alpha = 5-75 deg) and shows weak nonlinear opposition brightening at alpha< 5 deg, providing a more reliable absolute magnitude of Hv = 19.25 +- 0.03. The phase slope (0.039 +- 0.001 mag/deg) and opposition effect amplitude (parameterized by the ratio of intensity at alpha=0.3 deg to that at alpha=5 deg, I(0.3)/I(5)=1.31+-0.05) are consistent with those of typical C-type asteroids. We also attempted to determine the parameters for the Hapke model, which are applicable for constructing the surface reflectance map with the Hayabusa 2 onboard cameras. Although we could not constrain the full set of Hapke parameters, we obtained possible values, w=0.041, g=-0.38, B0=1.43, and h=0.050, assuming a surface roughness parameter theta=20 deg. By combining our photometric study with a thermal model of the asteroid (Mueller et al. in preparation), we obtained a geometric albedo of pv = 0.047 +- 0.003, phase integral q = 0.32 +- 0.03, and Bond albedo AB = 0.014 +- 0.002, which are commensurate with the values for common C-type asteroids.Comment: 27 pages, 4 figure, accepted for publication in the Astrophysical Journa

An Excursion-Set Model for the Structure of GMCs and the ISM

The ISM is governed by supersonic turbulence on a range of scales. We use this to develop a rigorous excursion-set model for the formation and time evolution of dense gas structures (GMCs, massive clumps, and cores). Supersonic turbulence drives the density distribution to a lognormal with dispersion increasing with Mach number; we generalize this to include scales >h (the disk scale height), and use it to construct the statistical properties of the density field smoothed on a scale R. We then compare conditions for self-gravitating collapse including thermal, turbulent, and rotational support. We show this becomes a well-defined barrier crossing problem. As such, an exact 'bound object mass function' can be derived, from scales of the sonic length to above the disk Jeans mass. This agrees remarkably well with observed GMC mass functions in the MW and other galaxies; the only inputs are the mass and size of the galaxies (to normalize the model). This explains the mass function cutoff and its power-law slope (close to, but shallower than, -2). The model also predicts the linewidth-size and size-mass relations of clouds and the dependence of their residuals on surface density/pressure. We use this to predict the spatial correlation function/clustering of clouds and star clusters; these also agree well with observations. We predict the size/mass function of ISM 'bubbles' or 'holes', and show this can account for observed HI hole distributions without any local feedback. We generalize the model to construct time-dependent 'merger/fragmentation trees' which can be used to follow cloud evolution and construct semi-analytic models for the ISM. We provide explicit recipes to construct the trees. We use a simple example to show that, if clouds are not destroyed in ~1-5 crossing times, then all ISM mass would be trapped in collapsing objects even if the large-scale turbulence were maintained.Comment: 21 pages, 11 figures, accepted to MNRAS (revised to match accepted version; predictions for high-redshift galaxies added

COMPARATIVE STUDY OF ANAPLASMA IN JAPAN AND OTHER COUNTRIES

To determine the reservoir animals and vector ticks for Anaplasma phagocytophilum in Far East Asia, which causes human granulocytic anaplasmosis, we analyzed tissue samples from deer and boars in Japan rodents in Taiwan and. Ixodes persulcatus in Russia by PCR-targeted. to 16S rDNA. Anaplasma species including Anaplasma bovis and. Anaplasma centrale-infected wild deer and boars were detected. The detection rates for A. phagocytophilum, A. bovis and. A. centrale in deer were 15,6 %, 21,9 % and. 37,5 %, respectively. These infection rates in wild boar were 3,6 %, 17,9 % and. 3,6 %, respectively. Wild rodents captured in Taiwan were positive for A. phagocytophilum. and. A. bovis. Prevalence rate of A. phagocytophilum. on I. persulcatus ticks in Irkutsk and. in Khabarovsk were 6,3 % and. 11,3 %, respectively. The 16SrDNA sequences detected from Russian ticks were identical to those of A. phagocytophilum. detected, in US and. Europe, and. from tick Ixodes ovatus and. Ixodes persulcatus in Japan. However the sequence detected from deer and boars in Japan were identical to sequences previously detected from deer and cattle in Japan, and. showed. less similarity (98,6 %) with typical A. phagocytophilum.. Sequences detected from wild rodents collected in Taiwan showed higher similarity (99,7 %) with typical A. phagocytophilum but formed the branch from those of A. phagocytophilum. detected in US and Europe. The finding suggests that the A. phagocytophilum-related sequence detected from deer and boars in Japan, and. wild rodents in Taiwan were different from those of typical A. phagocytophilum. found in Ixodid ticks

Coupling local to global star formation in spiral galaxies: the effect of differential rotation

Star formation is one of the key factors that shapes galaxies. This process is relatively well understood from both simulations and observations on a small ‘local’ scale of individual giant molecular clouds (GMCs) and also on a ‘global’ galaxy-wide scale (e.g. the Kennicutt–Schmidt law). However, there is still no understanding on how to connect global to local star formation scales and whether this connection is at all possible. Here, we analyse spatially resolved kinematics and the star formation rate (SFR) density ΣSFR for a combined sample of 17 nearby spiral galaxies obtained using our own optical observations in Hα for nine galaxies and neutral hydrogen radio observations combined with a multiwavelength spectral energy distribution analysis for eight galaxies from the THINGS project. We show that the azimuthally averaged normalized SFR density in spiral galaxies on a scale of a few hundred parsecs is proportional to the kinetic energy of GMC collisions due to differential rotation of the galactic disc. This energy is calculated from the rotation curve using the two Oort parameters A and B as log (ΣSFR/SFRtot)∝log [2A2 + 5B2]. The total kinetic energy of collision is defined by the shear velocity that is proportional to A and the spin energy of a cloud proportional to the vorticity B. Hence, shear does not act as a stabilizing factor for the cloud collapse thus reducing star formation but rather increases it by boosting the kinetic energy of collisions

Experimental and theoretical studies of Rhodamine B direct dye sorption onto clay-cellulose composite

Dyes are one of the main water pollutants and many biological and environmental problems are associated with them. Rhodamine B (RhB) is one of the most commonly used dye in the textile, printing, paints, and paper industry. The present work reports the sorptive removal of Rhodamine B direct dye from wastewater onto developed cellulose and clay composites. Sorbent material cellulose (48 g) was extracted from 80 g of bagasse. Then cellulose and two types of acid-activated clays were used to make efficient sorbent namely, composite I and II. Various characterization techniques were used to study the physiochemical properties of the synthesized composites. Different sorption affecting parameters were optimized such as initial dye concentration, time, temperature, pH, and composite dose for the efficient sorption of RhB onto composites. Equilibrium time was 60 min for composite-I and 80 min for composite-II Non-linear equilibrium isotherm and kinetic models demonstrated the fitness of Pseudo-second order and Redlich-Peterson isotherm. Composite-I and II removed 85.9% and 95.6% of RhB at pH 2 in 120 min, respectively. The sorption efficiency was checked, and sorbents were applied to real textile effluent which showed promising removal efficiency of over 90%. To confirm the experimental results, computational optimization and vibrational calculations were carried out using the Gaussian 09 program package with 3–21 G, 6–311 G, and 6–311+G basic sets. Geometric parameters showed the planar geometry. In the case of FTIR spectra, fundamental ring vibrations were observed with C-H and C-C. This study suggests that the developed composites have exceptional sorption ability to remove the dye contents from aqueous media

Thermococcus kodakarensis encodes three MCM homologs but only one is essential

The minichromosome maintenance (MCM) complex is thought to function as the replicative helicase in archaea and eukaryotes. In eukaryotes, this complex is an assembly of six different but related polypeptides (MCM2-7) but, in most archaea, one MCM protein assembles to form a homohexameric complex. Atypically, the Thermococcus kodakarensis genome encodes three archaeal MCM homologs, here designated MCM1-3, although MCM1 and MCM2 are unusual in having long and unique N-terminal extensions. The results reported establish that MCM2 and MCM3 assemble into homohexamers and exhibit DNA binding, helicase and ATPase activities in vitro typical of archaeal MCMs. In contrast, MCM1 does not form homohexamers and although MCM1 binds DNA and has ATPase activity, it has only minimal helicase activity in vitro. Removal of the N-terminal extension had no detectable effects on MCM1 but increased the helicase activity of MCM2. A T. kodakarensis strain with the genes TK0096 (MCM1) and TK1361 (MCM2) deleted has been constructed that exhibits no detectable defects in growth or viability, but all attempts to delete TK1620 (MCM3) have been unsuccessful arguing that that MCM3 is essential and is likely the replicative helicase in T. kodakarensis. The origins and possible function(s) of the three MCM proteins are discussed

A novel DNA nuclease is stimulated by association with the GINS complex

Chromosomal DNA replication requires the spatial and temporal coordination of the activities of several complexes that constitute the replisome. A previously uncharacterized protein, encoded by TK1252 in the archaeon Thermococcus kodakaraensis, was shown to stably interact with the archaeal GINS complex in vivo, a central component of the archaeal replisome. Here, we document that this protein (TK1252p) is a processive, single-strand DNA-specific exonuclease that degrades DNA in the 5′ → 3′ direction. TK1252p binds specifically to the GINS15 subunit of T. kodakaraensis GINS complex and this interaction stimulates the exonuclease activity in vitro. This novel archaeal nuclease, designated GINS-associated nuclease (GAN), also forms a complex in vivo with the euryarchaeal-specific DNA polymerase D. Roles for GAN in replisome assembly and DNA replication are discussed