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Found 37684 matches. Displaying 4391-4400
Berhani O, Nachmani D, Yamin R, Schmiedel D, Bar-On Y, Mandelboim O
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Vigilin Regulates the Expression of the Stress-Induced Ligand MICB by Interacting with Its 5 ' Untranslated Region

JOURNAL OF IMMUNOLOGY 2017 MAY 1; 198(9):3662-3670
NK cells are part of the innate immune system, and are able to identify and kill hazardous cells. The discrimination between normal and hazardous cells is possible due to an array of inhibitory and activating receptors. NKG2D is one of the prominent activating receptors expressed by all human NK cells. This receptor binds stress-induced ligands, including human MICA, MICB, and UL16-binding proteins 1-6. The interaction between NKG2D and its ligands facilitates the elimination of cells under cellular stress, such as tumor transformation. However, the mechanisms regulating the expression of these ligands are still not well understood. Under normal conditions, the NKG2D ligands were shown to be posttranscriptionally regulated by cellular microRNAs and RNA-binding proteins (RBPs). Thus far, only the 3' untranslated regions (UTR5) of MICA, MICB, and UL16-binding protein 2 were shown to be regulated by RBPs and microRNAs, usually resulting in their downregulation. In this study we investigated whether MICB expression is controlled by RBPs through its 5'UTR. We used an RNA pull-down assay followed by mass spectrometry and identified vigilin, a ubiquitously expressed multifunctional RNA-binding protein. We demonstrated that vigilin binds and negatively regulates MICB expression through its 5'UTR. Additionally, vigilin downregulation in target cells led to a significant increase in NK cell activation against said target cells. Taken together, we have discovered a novel mode of MICB regulation.
Bai B, Wang L, Lee M, Zhang YJ, Rahmadsyah, Alfiko Y, Ye BQ, Wan ZY, Lim CH, Suwanto A, Chua NH, Yue GH
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Genome-wide identification of markers for selecting higher oil content in oil palm

BMC PLANT BIOLOGY 2017 MAY 30; 17(?):? Article 93
Background: Oil palm (Elaeis guineensis, Jacq.) is the most important source of edible oil. The improvement of oil yield is currently slow in conventional breeding programs due to long generation intervals. Marker-assisted selection (MAS) has the potential to accelerate genetic improvement. To identify DNA markers associated with oil content traits for MAS, we performed quantitative trait loci (QTL) mapping using genotyping by sequencing (GBS) in a breeding population derived from a cross between Deli Dura and Ghana Pisifera, containing 153 F1 trees. Results: We constructed a high-density linkage map containing 1357 SNPs and 123 microsatellites. The 16 linkage groups (LGs) spanned 1527 cM, with an average marker space of 1.03 cM. One significant and three suggestive QTL for oil to bunch (O/B) and oil to dry mesocarp (O/DM) were mapped on LG1, LG8, and LG10 in a F1 breeding population, respectively. These QTL explained 7.6-13.3% of phenotypic variance. DNA markers associated with oil content in these QTL were identified. Trees with beneficial genotypes at two QTL for O/B showed an average O/B of 30.97%, significantly (P < 0.01) higher than that of trees without any beneficial QTL genotypes (average O/B of 28.24%). QTL combinations showed that the higher the number of QTL with beneficial genotypes, the higher the resulting average O/B in the breeding population. Conclusions: A linkage map with 1480 DNA markers was constructed and used to identify QTL for oil content traits. Pyramiding the identified QTL with beneficial genotypes associated with oil content traits using DNA markers has the potential to accelerate genetic improvement for oil yield in the breeding population of oil palm.
Bosch L, Bosch B, De Boeck K, Nawrot T, Meyts I, Vanneste D, Le Bourlegat CA, Croda J, da Silva LVRF
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Cystic fibrosis carriership and tuberculosis: hints toward an evolutionary selective advantage based on data from the Brazilian territory

BMC INFECTIOUS DISEASES 2017 MAY 12; 17(?):? Article 340
Background: The reason why Cystic Fibrosis (CF) is the most common fatal genetic disease among Caucasians has been incompletely studied. We aimed at deepening the hypothesis that CF carriers have a relative protection against Mycobacterium tuberculosis(Mtb) infection. Methods: Applying spatial epidemiology, we studied the link between CF carriership rate and tuberculosis ( TB) incidence in Brazil. We corrected for 5 potential environmental and 2 immunological confounders in this relation: monthly income, sanitary provisions, literacy rates, racial composition and population density along with AIDS incidence rates and diabetes mellitus type 2. Smoking data were incomplete and not available for analysis. Results: A significant, negative correlation between CF carriership rate and TB incidence, independent of any of the seven confounders was found. Conclusion: We provide exploratory support for the hypothesis that carrying a single CFTR mutation arms against Mtb infections.
Shi ZD, Lee K, Yang DP, Amin S, Verma N, Li QV, Zhu ZR, Soh CL, Kumar R, Evans T, Chen SB, Huangfu DW
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Genome Editing in hPSCs Reveals GATA6 Haploinsufficiency and a Genetic Interaction with GATA4 in Human Pancreatic Development

CELL STEM CELL 2017 MAY 4; 20(5):675-688
Human disease phenotypes associated with haploinsufficient gene requirements are often not recapitulated well in animal models. Here, we have investigated the association between human GATA6 haploinsufficiency and a wide range of clinical phenotypes that include neonatal and adult-onset diabetes using CRISPR (clustered regularly interspaced short palindromic repeat)/Cas9-mediated genome editing coupled with human pluripotent stem cell (hPSC) directed differentiation. We found that loss of one GATA6 allele specifically affects the differentiation of human pancreatic progenitors from the early PDX1+ stage to the more mature PDX1+NKX6.1+ stage, leading to impaired formation of glucose-responsive beta-like cells. In addition to this GATA6 haploinsufficiency, we also identified dosage-sensitive requirements for GATA6 and GATA4 in the formation of both definitive endoderm and pancreatic progenitor cells. Our work expands the application of hPSCs from studying the impact of individual gene loci to investigation of multigenic human traits, and it establishes an approach for identifying genetic modifiers of human disease.
Wang HQ, Gristick HB, Scharf L, West AP, Galimidi RP, Seaman MS, Freund NT, Nussenzweig MC, Bjorkman PJ
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Asymmetric recognition of HIV-1 Envelope trimer by V1V2 loop-targeting antibodies

ELIFE 2017 MAY 26; 6(?):? Article e27389
The HIV-1 envelope (Env) glycoprotein binds to host cell receptors to mediate membrane fusion. The prefusion Env trimer is stabilized by V1V2 loops that interact at the trimer apex. Broadly neutralizing antibodies (bNAbs) against V1V2 loops, exemplified by PG9, bind asymmetrically as a single Fab to the apex of the symmetric Env trimer using a protruding CDRH3 to penetrate the Env glycan shield. Here we characterized a distinct mode of V1V2 epitope recognition by the new bNAb BG1 in which two Fabs bind asymmetrically per Env trimer using a compact CDRH3. Comparisons between cryo-EM structures of Env trimer complexed with BG1 (6.2 A resolution) and PG9 (11.5 angstrom resolution) revealed a new V1V2-targeting strategy by BG1. Analyses of the EM structures provided information relevant to vaccine design including molecular details for different modes of asymmetric recognition of Env trimer and a binding model for BG1 recognition of V1V2 involving glycan flexibility.
Zhou Y, Crowley RS, Ben K, Prisinzano TE, Kreek MJ
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Synergistic blockade of alcohol escalation drinking in mice by a combination of novel kappa opioid receptor agonist Mesyl Salvinorin B and naltrexone

BRAIN RESEARCH 2017 MAY 1; 1662(?):75-86
Mesyl Salvinorin B (MSB) is a potent selective kappa opioid receptor (KOP-r) agonist that has potential for development as an anti-psychostimulant agent with fewer side-effects (e.g., sedation, depression and dysphoria) than classic KOP-r agonists. However, no such study has been done on alcohol. We investigated whether MSB alone or in combination with naltrexone (mu-opioid receptor antagonist) altered voluntary alcohol drinking in both male and female mice. Mice, subjected to 3 weeks of chronic escalation drinking (CED) in a two-bottle choice paradigm with 24-h access every other day, developed rapid escalation of alcohol intake and high preference. We found that single, acute administration of MSB dose dependently reduced alcohol intake and preference in mice after 3-week CED. The effect was specific to alcohol, as shown by the lack of any effect of MSB on sucrose or saccharin intake. We also used the drinking-in-the-dark (DID) model with limited access (4 h/day) to evaluate the pharmacological effect of MSB after 3 weeks of DID. However, MSB had no effect on alcohol drinking after 3-week DID. Upon investigation of potential synergistic effects between naltrexone and MSB, we found that acute administration of a combination of MSB and naltrexone reduced alcohol intake profoundly after 3-week CED at doses lower than those individual effective doses. Repeated administrations of this combination showed less tolerance development than repeated MSB alone. Our study suggests that the novel KOP-r agonist MSB both alone and in combination with naltrexone shows potential in alcoholism treatment models. (C) 2017 Elsevier B.V. All rights reserved.
Farrell DL, Weitz O, Magnasco MO, Zallen JA
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SEGGA: a toolset for rapid automated analysis of epithelial cell polarity and dynamics

DEVELOPMENT 2017 MAY 1; 144(9):1725-1734
Epithelial remodeling determines the structure of many organs in the body through changes in cell shape, polarity and behavior and is a major area of study in developmental biology. Accurate and high-throughput methods are necessary to systematically analyze epithelial organization and dynamics at single-cell resolution. We developed SEGGA, an easy-to-use software for automated image segmentation, cell tracking and quantitative analysis of cell shape, polarity and behavior in epithelial tissues. SEGGA is free, open source, and provides a full suite of tools that allow users with no prior computational expertise to independently perform all steps of automated image segmentation, semi-automated user-guided error correction, and data analysis. Here we use SEGGA to analyze changes in cell shape, cell interactions and planar polarity during convergent extension in the Drosophila embryo. These studies demonstrate that planar polarity is rapidly established in a spatiotemporally regulated pattern that is dynamically remodeled in response to changes in cell orientation. These findings reveal an unexpected plasticity that maintains coordinated planar polarity in actively moving populations through the continual realignment of cell polarity with the tissue axes.
Fang Z, Cao H, Stoffel E, Cohen P
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Role of Perivascular Adipose Tissue in Vascular Physiology and Pathology

HYPERTENSION 2017 MAY; 69(5):770-777
Lorin V, Malbec M, Eden C, Bruel T, Porrot F, Seaman MS, Schwartz O, Mouquet H
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Broadly neutralizing antibodies suppress post-transcytosis HIV-1 infectivity

MUCOSAL IMMUNOLOGY 2017 MAY; 10(3):814-826
Broadly neutralizing antibodies (bNAbs) offer promising opportunities for preventing HIV-1 infection in humans. Immunoprophylaxis with potent bNAbs efficiently protects non-human primates from mucosal transmission even after repeated challenges. However, the precise mechanisms of bNAb-mediated viral inhibition in mucosal tissues are currently unknown. Here, we show that immunoglobulin (Ig)G and IgA bNAbs do not interfere with the endocytic transport of HIV-1 across epithelial cells, a process referred to as transcytosis. Instead, both viruses and antibodies are translocated to the basal pole of epithelial cells, possibly in the form of an immune complex. Importantly, as opposed to free virions, viral particles bound by bNAbs are no longer infectious after transepithelial transit. Post-transcytosis neutralization activity of bNAbs displays comparable inhibitory concentrations as those measured in classical neutralization assays. Thus, bNAbs do not block the transport of incoming HIV-1 viruses across the mucosal epithelium but rather neutralize the transcytosed virions, highlighting their efficient prophylactic and protective activity in vivo.