The GATA1s isoform is normally down-regulated during terminal haematopoietic differentiation and over-expression leads to failure to repress MYB, CCND2 and SKI during erythroid differentiation of K562 cells

Background: Although GATA1 is one of the most extensively studied haematopoietic transcription factors little is currently known about the physiological functions of its naturally occurring isoforms GATA1s and GATA1FL in humans—particularly whether the isoforms have distinct roles in different lineages and whether they have non-redundant roles in haematopoietic differentiation. As well as being of general interest to understanding of haematopoiesis, GATA1 isoform biology is important for children with Down syndrome associated acute megakaryoblastic leukaemia (DS-AMKL) where GATA1FL mutations are an essential driver for disease pathogenesis. <p/>Methods: Human primary cells and cell lines were analyzed using GATA1 isoform specific PCR. K562 cells expressing GATA1s or GATA1FL transgenes were used to model the effects of the two isoforms on in vitro haematopoietic differentiation. <p/>Results: We found no evidence for lineage specific use of GATA1 isoforms; however GATA1s transcripts, but not GATA1FL transcripts, are down-regulated during in vitro induction of terminal megakaryocytic and erythroid differentiation in the cell line K562. In addition, transgenic K562-GATA1s and K562-GATA1FL cells have distinct gene expression profiles both in steady state and during terminal erythroid differentiation, with GATA1s expression characterised by lack of repression of MYB, CCND2 and SKI. <p/>Conclusions: These findings support the theory that the GATA1s isoform plays a role in the maintenance of proliferative multipotent megakaryocyte-erythroid precursor cells and must be down-regulated prior to terminal differentiation. In addition our data suggest that SKI may be a potential therapeutic target for the treatment of children with DS-AMKL

MAXIPOL: a balloon-borne experiment for measuring the polarization anisotropy of the cosmic microwave background radiation

We discuss MAXIPOL, a bolometric balloon-borne experiment designed to measure the E-mode polarization anisotropy of the cosmic microwave background radiation (CMB) on angular scales of 10 arcmin to 2 degrees. MAXIPOL is the first CMB experiment to collect data with a polarimeter that utilizes a rotating half-wave plate and fixed wire-grid polarizer. We present the instrument design, elaborate on the polarimeter strategy and show the instrument performance during flight with some time domain data. Our primary data set was collected during a 26 hour turnaround flight that was launched from the National Scientific Ballooning Facility in Ft. Sumner, New Mexico in May 2003. During this flight five regions of the sky were mapped. Data analysis is in progress

AHR2 Mutant Reveals Functional Diversity of Aryl Hydrocarbon Receptors in Zebrafish

The aryl hydrocarbon receptor (AHR) is well known for mediating the toxic effects of TCDD and has been a subject of intense research for over 30 years. Current investigations continue to uncover its endogenous and regulatory roles in a wide variety of cellular and molecular signaling processes. A zebrafish line with a mutation in ahr2 (ahr2hu3335), encoding the AHR paralogue responsible for mediating TCDD toxicity in zebrafish, was developed via Targeting Induced Local Lesions IN Genomes (TILLING) and predicted to express a non-functional AHR2 protein. We characterized AHR activity in the mutant line using TCDD and leflunomide as toxicological probes to investigate function, ligand binding and CYP1A induction patterns of paralogues AHR2, AHR1A and AHR1B. By evaluating TCDD-induced developmental toxicity, mRNA expression changes and CYP1A protein in the AHR2 mutant line, we determined that ahr2hu3335 zebrafish are functionally null. In silico modeling predicted differential binding of TCDD and leflunomide to the AHR paralogues. AHR1A is considered a non-functional pseudogene as it does not bind TCCD or mediate in vivo TCDD toxicity. Homology modeling, however, predicted a ligand binding conformation of AHR1A with leflunomide. AHR1A-dependent CYP1A immunohistochemical expression in the liver provided in vivo confirmation of the in silico docking studies. The ahr2hu3335 functional knockout line expands the experimental power of zebrafish to unravel the role of the AHR during development, as well as highlights potential activity of the other AHR paralogues in ligand-specific toxicological responses

Optoelectronic characterization of CuInGa(S)2 thin films grown by spray pyrolysis for photovoltaic application

[EN] Copper-indium gallium disulfide (CIGS) is a good absorber for photovoltaic application. Thin films of CIGS were prepared by spray pyrolysis on glass substrates in the ambient atmosphere. The films were characterized by different techniques, such as structural, morphological, optical and electrical properties of CIGS films were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), spectrophotometer and Hall effect, respectively. After optimization, the deposited films structure, grain size, and crystallinity became more important with an increase of annealing time at 370 degrees C for 20 min. Transmission electron microscopy (TEM) analysis shows that the interface sheets are well crystallized and the inter planer distance are 0.25 nm, 0.28 nm, and 0.36 nm. The atomic force microscopy (AFM) observation shows that the grain size and roughness can be tolerated by optimizing the annealing time. The strong absorbance and low transmittance were observed for the prepared films with a suitable energy bandgap about 1.46 eV. The Hall effect measurement system examined that CIGS films exhibited optimal electrical properties, resistivity, carrier mobility, and carrier concentration which were determined to be 4.22 x 10(6) omega cm, 6.18 x 10(2) cm(2) V-1 S-1 and 4.22 x 10(6) cm(-3), respectively. The optoelectronic properties of CIGS material recommended being used for the photovoltaic application.Prof. Bouchaib HARTITI, The Senior Associate at ICTP, is very grateful to ICTP for permanent support. Prof. Mohamed Ebn Touhami, Director of the University Center for Analysis, Expertise, Transfer of Technology and Incubation, Kenitra, Morocco, is very grateful to CUA2TI for financial support. Thanks to Doctor Diogo M.F. Santos for the supervision of Amal Bouich's work during her research in CeFEMA research center. The authors also thank researchers from CeFEMA (IST-ULisboa, Portugal) and CUA2TI (FS-Kenitra Morocco) for their help.Bouich, A.; Hartiti, B.; Ullah, S.; Ullah, H.; Ebn Touhami, M.; Santos, DMF.; Marí, B. (2019). Optoelectronic characterization of CuInGa(S)2 thin films grown by spray pyrolysis for photovoltaic application. Applied Physics A. 125(8):1-9. https://doi.org/10.1007/s00339-019-2874-4S191258T. Feurer, P. Reinhard, E. Avancini, B. Bissig, J. Löckinger, P. Fuchs, S. Buecheler, Progress in thin film CIGS photovoltaics–Research and development, manufacturing, and applications. Prog. Photovolt. Res. Appl. 25(7), 645–667 (2017)A. Zegadi, M.A. Slifkin, M. Djamin, A.E. Hill, R.D. Tomlinson, A photoacoustic study of CuInxGa1− xSe2 alloys. Phys. Status Solidi (A) 133(2), 533–540 (1992)T.H. Sajeesh, A.R. Warrier, C.S. Kartha, K.P. Vijayakumar, Optimization of parameters of chemical spray pyrolysis technique to get n and p-type layers of SnS. Thin Solid Films 518(15), 4370–4374 (2010)J. Liu, D. Zhuang, H. Luan, M. Cao, M. Xie, X. Li, Preparation of Cu (In, Ga) Se2 thin film by sputtering from Cu (In, Ga) Se2 quaternary target. Progr. Nat. Sci. Mater. Int. 23(2), 133–138 (2013)M.I. Hossain, Fabrication and characterization of CIGS solar cells with In2 S3 buffer layer deposited by PVD technique. Chalcogenide Lett. 9(5), 185–191 (2012)M.A. Mughal, R. Engelken, R. Sharma, Progress in indium (III) sulfide (In2S3) buffer layer deposition techniques for CIS, CIGS, and CdTe-based thin film solar cells. Sol. Energy 120, 131–146 (2015)M. Powalla, M. Cemernjak, J. Eberhardt, F. Kessler, R. Kniese, H.D. Mohring, B. Dimmler, Large-area CIGS modules: Pilot line production and new developments. Sol. Energy Mater Sol. Cells 90(18–19), 3158–3164 (2006)M.E. Calixto, P.J. Sebastian, R.N. Bhattacharya, R. Noufi, Compositional and optoelectronic properties of CIS and CIGS thin films formed by electrodeposition. Sol. Energy Mater. Sol. Cells 59(1–2), 75–84 (1999)S. Jung, S. Ahn, J.H. Yun, J. Gwak, D. Kim, K. Yoon, Effects of Ga contents on properties of CIGS thin films and solar cells fabricated by co-evaporation technique. Curr. Appl. Phys. 10(4), 990–996 (2010)S. R. Ovshinsky, X. Deng, R. Young, U.S. Patent No. 5,231,047. Washington, DC: U.S. Patent and Trademark Office (1993).M. Kaelin, D. Rudmann, A.N. Tiwari, Low cost processing of CIGS thin film solar cells. Sol. Energy 77(6), 749–756 (2004)Fangdan Jiang, Jiayou Feng, Effect of temperature on selenization process of metallic Cu–In alloy precursors. Thin Solid Films 515(4), 1950–1955 (2006)S. Shirakata, Y. Kannaka, H. Hasegawa, T. Kariya, S. Isomura, Properties of Cu (In, Ga) Se2 thin films prepared by chemical spray pyrolysis. Jpn. J. Appl. Phys. 38(9R), 4997 (1999)Y.K. Kumar, G.S. Babu, P.U. Bhaskar, V.S. Raja, Effect of starting-solution pH on the growth of Cu2ZnSnS4 thin films deposited by spray pyrolysis. Phys. Status Solidi (A) 206(7), 1525–1530 (2009)M. Ajili, M. Castagné, N.K. Turki, Characteristics of CuIn1− xGaxS2 thin films synthesized by chemical spray pyrolysis. J. Lumin. 150, 1–7 (2014)B.J. Babu, S. Velumani, A. Kassiba, R. Asomoza, J.A. Chavez-Carvayar, J. Yi, Deposition and characterization of graded Cu (In1-xGax) Se2 thin films by spray pyrolysis. Mater. Chem. Phys. 162, 59–68 (2015)S.F. Varol, G. Babür, G. Çankaya, U. Kölemen, Synthesis of sol–gel derived nano-crystalline ZnO thin films as TCO window layer: effect of sol aging and boron. RSC Adv. 4(100), 56645–56653 (2014)J.A. Frantz, R.Y. Bekele, V.Q. Nguyen, J.S. Sanghera, A. Bruce, S.V. Frolov, I.D. Aggarwal, Cu (In, Ga) Se2 thin films and devices sputtered from a single target without additional selenization. Thin Solid Films 519(22), 7763–7765 (2011)C. Calderón, G. Gordillo, P. Bartolo-Pérez, F. Mesa, Effect of the deposition conditions on the optical, morphological and compositional properties of CuIn1− xGaxSe2 thin films prepared by a multistage process. 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Cure of ADPKD by Selection for Spontaneous Genetic Repair Events in Pkd1-Mutated iPS Cells

Induced pluripotent stem cells (iPSCs) generated by epigenetic reprogramming of personal somatic cells have limited therapeutic capacity for patients suffering from genetic disorders. Here we demonstrate restoration of a genomic mutation heterozygous for Pkd1 (polycystic kidney disease 1) deletion (Pkd1(+/−) to Pkd1(+/R+)) by spontaneous mitotic recombination. Notably, recombination between homologous chromosomes occurred at a frequency of 1∼2 per 10,000 iPSCs. Southern blot hybridization and genomic PCR analyses demonstrated that the genotype of the mutation-restored iPSCs was indistinguishable from that of the wild-type cells. Importantly, the frequency of cyst generation in kidneys of adult chimeric mice containing Pkd1(+/R+) iPSCs was significantly lower than that of adult chimeric mice with parental Pkd1(+/−) iPSCs, and indistinguishable from that of wild-type mice. This repair step could be directly incorporated into iPSC development programmes prior to cell transplantation, offering an invaluable step forward for patients carrying a wide range of genetic disorders

Tear fluid biomarkers in ocular and systemic disease: potential use for predictive, preventive and personalised medicine

In the field of predictive, preventive and personalised medicine, researchers are keen to identify novel and reliable ways to predict and diagnose disease, as well as to monitor patient response to therapeutic agents. In the last decade alone, the sensitivity of profiling technologies has undergone huge improvements in detection sensitivity, thus allowing quantification of minute samples, for example body fluids that were previously difficult to assay. As a consequence, there has been a huge increase in tear fluid investigation, predominantly in the field of ocular surface disease. As tears are a more accessible and less complex body fluid (than serum or plasma) and sampling is much less invasive, research is starting to focus on how disease processes affect the proteomic, lipidomic and metabolomic composition of the tear film. By determining compositional changes to tear profiles, crucial pathways in disease progression may be identified, allowing for more predictive and personalised therapy of the individual. This article will provide an overview of the various putative tear fluid biomarkers that have been identified to date, ranging from ocular surface disease and retinopathies to cancer and multiple sclerosis. Putative tear fluid biomarkers of ocular disorders, as well as the more recent field of systemic disease biomarkers, will be shown

Abortive Lytic Reactivation of KSHV in CBF1/CSL Deficient Human B Cell Lines

Since Kaposi's sarcoma associated herpesvirus (KSHV) establishes a persistent infection in human B cells, B cells are a critical compartment for viral pathogenesis. RTA, the replication and transcription activator of KSHV, can either directly bind to DNA or use cellular DNA binding factors including CBF1/CSL as DNA adaptors. In addition, the viral factors LANA1 and vIRF4 are known to bind to CBF1/CSL and modulate RTA activity. To analyze the contribution of CBF1/CSL to reactivation in human B cells, we have successfully infected DG75 and DG75 CBF1/CSL knock-out cell lines with recombinant KSHV.219 and selected for viral maintenance by selective medium. Both lines maintained the virus irrespective of their CBF1/CSL status. Viral reactivation could be initiated in both B cell lines but viral genome replication was attenuated in CBF1/CSL deficient lines, which also failed to produce detectable levels of infectious virus. Induction of immediate early, early and late viral genes was impaired in CBF1/CSL deficient cells at multiple stages of the reactivation process but could be restored to wild-type levels by reintroduction of CBF1/CSL. To identify additional viral RTA target genes, which are directly controlled by CBF1/CSL, we analyzed promoters of a selected subset of viral genes. We show that the induction of the late viral genes ORF29a and ORF65 by RTA is strongly enhanced by CBF1/CSL. Orthologs of ORF29a in other herpesviruses are part of the terminase complex required for viral packaging. ORF65 encodes the small capsid protein essential for capsid shell assembly. Our study demonstrates for the first time that in human B cells viral replication can be initiated in the absence of CBF1/CSL but the reactivation process is severely attenuated at all stages and does not lead to virion production. Thus, CBF1/CSL acts as a global hub which is used by the virus to coordinate the lytic cascade

Design Considerations for Tumor-Targeted Nanoparticles

Inorganic/organic hybrid nanoparticles are potentially useful in biomedicine, but to avoid non-specific background fluorescence and long-term toxicity, they need to be cleared from the body within a reasonable timescale1. Previously, we have shown that rigid spherical nanoparticles such as quantum dots can be cleared by the kidneys if they have a hydrodynamic diameter of approximately 5.5 nm and a zwitterionic surface charge2. Here, we show that quantum dots functionalized with high-affinity small-molecule ligands that target tumours can also be cleared by the kidneys if their hydrodynamic diameter is less than this value, which sets an upper limit of 5–10 ligands per quantum dot for renal clearance. Animal models of prostate cancer and melanoma show receptor-specific imaging and renal clearance within 4 h post-injection. This study suggests a set of design rules for the clinical translation of targeted nanoparticles that can be eliminated through the kidneys.National Science Foundation (U.S.) (NSF-0070319)National Institutes of Health (U.S.) (NIH GM68762)National Institutes of Health (U.S.) (NIH grant no. R33-EB-000673)National Institutes of Health (U.S.) ( NIH grant no. R01-CA-115296)National Institutes of Health (U.S.) (MIT-Harvard NanoMedical Consortium (1U54-CA119349, a Center of Cancer Nanotechnology Excellence))Bank of AmericaMedical Foundation, inc. (Charles A. King Trust Postdoctoral Research Fellowship Program)cance

Directing the evolution of Rubisco and Rubisco activase: first impressions of a new tool for photosynthesis research

During the last decade the practice of laboratory-directed protein evolution has become firmly established as a versatile tool in biochemical research by enabling molecular evolution toward desirable phenotypes or detection of novel structure–function interactions. Applications of this technique in the field of photosynthesis research are still in their infancy, but recently first steps have been reported in the directed evolution of the CO2-fixing enzyme Rubisco and its helper protein Rubisco activase. Here we summarize directed protein evolution strategies and review the progressive advances that have been made to develop and apply suitable selection systems for screening mutant forms of these enzymes that improve the fitness of the host organism. The goal of increasing photosynthetic efficiency of plants by improving the kinetics of Rubisco has been a long-term goal scoring modest successes. We discuss how directed evolution methodologies may one day be able to circumvent the problems encountered during this venture