Multiwavelength Bulge-Disk Decomposition for the Galaxy M81 (NGC 3031). I. Morphology

A panchromatic investigation of morphology for the early-type spiral galaxy M81 is presented in this paper. We perform bulge-disk decomposition in M81 images at totally 20 wavebands from FUV to NIR obtained with GALEX, Swift, SDSS, WIYN, 2MASS, WISE, and Spitzer. Morphological parameters such as Sersic index, effective radius, position angle, and axis ratio for the bulge and the disk are thus derived at all the wavebands, which enables quantifying the morphological K-correction for M81 and makes it possible to reproduce images for the bulge and the disk in the galaxy at any waveband. The morphology as a function of wavelength appears as a variable-slope trend of the Sersic index and the effective radius, in which the variations are steep at UV--optical and shallow at optical--NIR bands; the position angle and the axis ratio keep invariable at least at optical--NIR bands. It is worth noting that, the Sersic index for the bulge reaches to about 4--5 at optical and NIR bands, but drops to about 1 at UV bands. This difference brings forward a caveat that, a classical bulge is likely misidentified for a pseudo-bulge or no bulge at high redshifts where galaxies are observed through rest-frame UV channels with optical telescopes. The next work of this series is planned to study spatially resolved SEDs for the bulge and the disk, respectively, and thereby explore stellar population properties and star formation/quenching history for the the galaxy composed of the subsystems.Comment: 48 Pages, 38 Figures, 5 Tables; Accepted for Publication in The Astrophysical Journal Supplement Serie

Stable reduction of CCR5 by RNAi through hematopoietic stem cell transplant in non-human primates

RNAi is a powerful method for suppressing gene expression that has tremendous potential for therapeutic applications. However, because endogenous RNAi plays a role in normal cellular functions, delivery and expression of siRNAs must be balanced with safety. Here we report successful stable expression in primates of siRNAs directed to chemokine (c-c motif) receptor 5 (CCR5) introduced through CD34+ hematopoietic stem/progenitor cell transplant. After hematopoietic reconstitution, to date 14 months after transplant, we observe stably marked lymphocytes expressing siRNAs and consistent down-regulation of chemokine (c-c motif) receptor 5 expression. The marked cells are less susceptible to simian immunodeficiency virus infection ex vivo. These studies provide a successful demonstration that siRNAs can be used together with hematopoietic stem cell transplant to stably modulate gene expression in primates and potentially treat blood diseases such as HIV-1

Optimization and Functional Effects of Stable Short Hairpin RNA Expression in Primary Human Lymphocytes via Lentiviral Vectors

Specific, potent, and sustained short hairpin RNA (shRNA)-mediated gene silencing is crucial for the successful application of RNA interference technology to therapeutic interventions. We examined the effects of shRNA expression in primary human lymphocytes (PBLs) using lentiviral vectors bearing different RNA polymerase III promoters. We found that the U6 promoter is more efficient than the H1 promoter for shRNA expression and for reducing expression of CCR5 in PBLs. However, shRNA expression from the U6 promoter resulted in a gradual decline of the transduced cell populations. With one CCR5 shRNA this decline could be attributed to elevated apoptosis but another CCR5 shRNA that caused cytotoxicity did not show evidence of apoptosis, suggesting sequence-specific mechanisms for cytotoxicity. In contrast to the U6 promoter, PBLs transduced by vectors expressing shRNAs from the H1 promoter could be maintained without major cytotoxic effects. Since a lower level of shRNA expression appears to be advantageous to maintaining the shRNA-transduced population, lentiviral vectors bearing the H1 promoter are more suitable for stable transduction and expression of shRNA in primary human T lymphocytes. Our results suggest that functional shRNA screens should include tests for both potency and adverse metabolic effects upon primary cells

Role of exosomes in non-small cell lung cancer and EGFR-mutated lung cancer

As an important mediator of information transfer between cells, exosomes play a unique role in regulating tumor growth, supporting vascular proliferation, tumor invasion, and metastasis. Exosomes are widely present in various body fluids, and therefore they can be used as a potential tool for non-invasive liquid biopsy. The present study reviews the role of exosomes in liquid biopsy, tumor microenvironment formation, and epithelial-mesenchymal transition in non-small cell lung cancer (NSCLC). By targeting epidermal growth factor receptor (EGFR) therapy as a first-line treatment for patients with NSCLC, this study also briefly describes the occurrence of EGRF+ exosomes and the role of exosomes and their contents in non-invasive detection and potential therapeutic targets in EGFR-mutated lung cancer

The LAMOST Survey of Background Quasars in the Vicinity of the Andromeda and Triangulum Galaxies -- II. Results from the Commissioning Observations and the Pilot Surveys

We present new quasars discovered in the vicinity of the Andromeda and Triangulum galaxies with the LAMOST during the 2010 and 2011 observational seasons. Quasar candidates are selected based on the available SDSS, KPNO 4 m telescope, XSTPS optical, and WISE near infrared photometric data. We present 509 new quasars discovered in a stripe of ~135 sq. deg from M31 to M33 along the Giant Stellar Stream in the 2011 pilot survey datasets, and also 17 new quasars discovered in an area of ~100 sq. deg that covers the central region and the southeastern halo of M31 in the 2010 commissioning datasets. These 526 new quasars have i magnitudes ranging from 15.5 to 20.0, redshifts from 0.1 to 3.2. They represent a significant increase of the number of identified quasars in the vicinity of M31 and M33. There are now 26, 62 and 139 known quasars in this region of the sky with i magnitudes brighter than 17.0, 17.5 and 18.0 respectively, of which 5, 20 and 75 are newly-discovered. These bright quasars provide an invaluable collection with which to probe the kinematics and chemistry of the ISM/IGM in the Local Group of galaxies. A total of 93 quasars are now known with locations within 2.5 deg of M31, of which 73 are newly discovered. Tens of quasars are now known to be located behind the Giant Stellar Stream, and hundreds behind the extended halo and its associated substructures of M31. The much enlarged sample of known quasars in the vicinity of M31 and M33 can potentially be utilized to construct a perfect astrometric reference frame to measure the minute PMs of M31 and M33, along with the PMs of substructures associated with the Local Group of galaxies. Those PMs are some of the most fundamental properties of the Local Group.Comment: 26 pages, 6 figures, AJ accepte

A Small-molecule Inhibitor Directed against the Chemokine Receptor CXCR4 Prevents its Use as an HIV-1 Coreceptor

The chemokine receptor CXCR4 is the major coreceptor used for cellular entry by T cell– tropic human immunodeficiency virus (HIV)-1 strains, whereas CCR5 is used by macrophage (M)-tropic strains. Here we show that a small-molecule inhibitor, ALX40-4C, inhibits HIV-1 envelope (Env)-mediated membrane fusion and viral entry directly at the level of coreceptor use. ALX40-4C inhibited HIV-1 use of the coreceptor CXCR4 by T- and dual-tropic HIV-1 strains, whereas use of CCR5 by M- and dual-tropic strains was not inhibited. Dual-tropic viruses capable of using both CXCR4 and CCR5 were inhibited by ALX40-4C only when cells expressed CXCR4 alone. ALX40-4C blocked stromal-derived factor (SDF)-1α–mediated activation of CXCR4 and binding of the monoclonal antibody 12G5 to cells expressing CXCR4. Overlap of the ALX40-4C binding site with that of 12G5 and SDF implicates direct blocking of Env interactions, rather than downregulation of receptor, as the mechanism of inhibition. Thus, ALX40-4C represents a small-molecule inhibitor of HIV-1 infection that acts directly against a chemokine receptor at the level of Env-mediated membrane fusion

Arabidopsis Fatty Acid Desaturase FAD2 Is Required for Salt Tolerance during Seed Germination and Early Seedling Growth

Fatty acid desaturases play important role in plant responses to abiotic stresses. However, their exact function in plant resistance to salt stress is unknown. In this work, we provide the evidence that FAD2, an endoplasmic reticulum localized ω-6 desaturase, is required for salt tolerance in Arabidopsis. Using vacuolar and plasma membrane vesicles prepared from the leaves of wild-type (Col-0) and the loss-of-function Arabidopsis mutant, fad2, which lacks the functional FAD2, we examined the fatty acid composition and Na+-dependent H+ movements of the isolated vesicles. We observed that, when compared to Col-0, the level of vacuolar and plasma membrane polyunsaturation was lower, and the Na+/H+ exchange activity was reduced in vacuolar and plasma membrane vesicles isolated from fad2 mutant. Consistent with the reduced Na+/H+ exchange activity, fad2 accumulated more Na+ in the cytoplasm of root cells, and was more sensitive to salt stress during seed germination and early seedling growth, as indicated by CoroNa-Green staining, net Na+ efflux and salt tolerance analyses. Our results suggest that FAD2 mediated high-level vacuolar and plasma membrane fatty acid desaturation is essential for the proper function of membrane attached Na+/H+ exchangers, and thereby to maintain a low cytosolic Na+ concentration for salt tolerance during seed germination and early seedling growth in Arabidopsis