ic NF-{kappa}B mediates lipopolysaccharide-induced alternative pre-mRNA splicing of MyD88 in mouse macrophages [Signal Transduction] By feedproxy.google.com Published On :: 2020-05-01T00:06:09-07:00 Although a robust inflammatory response is needed to combat infection, this response must ultimately be terminated to prevent chronic inflammation. One mechanism that terminates inflammatory signaling is the production of alternative mRNA splice forms in the Toll-like receptor (TLR) signaling pathway. Whereas most genes in the TLR pathway encode positive mediators of inflammatory signaling, several, including that encoding the MyD88 signaling adaptor, also produce alternative spliced mRNA isoforms that encode dominant-negative inhibitors of the response. Production of these negatively acting alternatively spliced isoforms is induced by stimulation with the TLR4 agonist lipopolysaccharide (LPS); thus, this alternative pre-mRNA splicing represents a negative feedback loop that terminates TLR signaling and prevents chronic inflammation. In the current study, we investigated the mechanisms regulating the LPS-induced alternative pre-mRNA splicing of the MyD88 transcript in murine macrophages. We found that 1) the induction of the alternatively spliced MyD88 form is due to alternative pre-mRNA splicing and not caused by another RNA regulatory mechanism, 2) MyD88 splicing is regulated by both the MyD88- and TRIF-dependent arms of the TLR signaling pathway, 3) MyD88 splicing is regulated by the NF-κB transcription factor, and 4) NF-κB likely regulates MyD88 alternative pre-mRNA splicing per se rather than regulating splicing indirectly by altering MyD88 transcription. We conclude that alternative splicing of MyD88 may provide a sensitive mechanism that ensures robust termination of inflammation for tissue repair and restoration of normal tissue homeostasis once an infection is controlled. Full Article
ic Kruppel-like factor 3 (KLF3) suppresses NF-{kappa}B-driven inflammation in mice [Immunology] By feedproxy.google.com Published On :: 2020-05-01T00:06:09-07:00 Bacterial products such as lipopolysaccharides (or endotoxin) cause systemic inflammation, resulting in a substantial global health burden. The onset, progression, and resolution of the inflammatory response to endotoxin are usually tightly controlled to avoid chronic inflammation. Members of the NF-κB family of transcription factors are key drivers of inflammation that activate sets of genes in response to inflammatory signals. Such responses are typically short-lived and can be suppressed by proteins that act post-translationally, such as the SOCS (suppressor of cytokine signaling) family. Less is known about direct transcriptional regulation of these responses, however. Here, using a combination of in vitro approaches and in vivo animal models, we show that endotoxin treatment induced expression of the well-characterized transcriptional repressor Krüppel-like factor 3 (KLF3), which, in turn, directly repressed the expression of the NF-κB family member RELA/p65. We also observed that KLF3-deficient mice were hypersensitive to endotoxin and exhibited elevated levels of circulating Ly6C+ monocytes and macrophage-derived inflammatory cytokines. These findings reveal that KLF3 is a fundamental suppressor that operates as a feedback inhibitor of RELA/p65 and may be important in facilitating the resolution of inflammation. Full Article
ic Affinity maturation, humanization, and co-crystallization of a rabbit anti-human ROR2 monoclonal antibody for therapeutic applications [Immunology] By feedproxy.google.com Published On :: 2020-05-01T00:06:09-07:00 Antibodies are widely used as cancer therapeutics, but their current use is limited by the low number of antigens restricted to cancer cells. A receptor tyrosine kinase, receptor tyrosine kinase-like orphan receptor 2 (ROR2), is normally expressed only during embryogenesis and is tightly down-regulated in postnatal healthy tissues. However, it is up-regulated in a diverse set of hematologic and solid malignancies, thus ROR2 represents a candidate antigen for antibody-based cancer therapy. Here we describe the affinity maturation and humanization of a rabbit mAb that binds human and mouse ROR2 but not human ROR1 or other human cell-surface antigens. Co-crystallization of the parental rabbit mAb in complex with the human ROR2 kringle domain (hROR2-Kr) guided affinity maturation by heavy-chain complementarity-determining region 3 (HCDR3)-focused mutagenesis and selection. The affinity-matured rabbit mAb was then humanized by complementarity-determining region (CDR) grafting and framework fine tuning and again co-crystallized with hROR2-Kr. We show that the affinity-matured and humanized mAb retains strong affinity and specificity to ROR2 and, following conversion to a T cell–engaging bispecific antibody, has potent cytotoxicity toward ROR2-expressing cells. We anticipate that this humanized affinity-matured mAb will find application for antibody-based cancer therapy of ROR2-expressing neoplasms. Full Article
ic Three distinct glycosylation pathways are involved in the decoration of Lactococcus lactis cell wall glycopolymers [Microbiology] By feedproxy.google.com Published On :: 2020-04-17T00:06:05-07:00 Extracytoplasmic sugar decoration of glycopolymer components of the bacterial cell wall contributes to their structural diversity. Typically, the molecular mechanism that underpins such a decoration process involves a three-component glycosylation system (TGS) represented by an undecaprenyl-phosphate (Und-P) sugar-activating glycosyltransferase (Und-P GT), a flippase, and a polytopic glycosyltransferase (PolM GT) dedicated to attaching sugar residues to a specific glycopolymer. Here, using bioinformatic analyses, CRISPR-assisted recombineering, structural analysis of cell wall–associated polysaccharides (CWPS) through MALDI-TOF MS and methylation analysis, we report on three such systems in the bacterium Lactococcus lactis. On the basis of sequence similarities, we first identified three gene pairs, csdAB, csdCD, and csdEF, each encoding an Und-P GT and a PolM GT, as potential TGS component candidates. Our experimental results show that csdAB and csdCD are involved in Glc side-chain addition on the CWPS components rhamnan and polysaccharide pellicle (PSP), respectively, whereas csdEF plays a role in galactosylation of lipoteichoic acid (LTA). We also identified a potential flippase encoded in the L. lactis genome (llnz_02975, cflA) and confirmed that it participates in the glycosylation of the three cell wall glycopolymers rhamnan, PSP, and LTA, thus indicating that its function is shared by the three TGSs. Finally, we observed that glucosylation of both rhamnan and PSP can increase resistance to bacteriophage predation and that LTA galactosylation alters L. lactis resistance to bacteriocin. Full Article
ic Cell-specific expression of the transcriptional regulator RHAMM provides a timing mechanism that controls appropriate wound re-epithelialization [Glycobiology and Extracellular Matrices] By feedproxy.google.com Published On :: 2020-04-17T00:06:05-07:00 Prevention of aberrant cutaneous wound repair and appropriate regeneration of an intact and functional integument require the coordinated timing of fibroblast and keratinocyte migration. Here, we identified a mechanism whereby opposing cell-specific motogenic functions of a multifunctional intracellular and extracellular protein, the receptor for hyaluronan-mediated motility (RHAMM), coordinates fibroblast and keratinocyte migration speed and ensures appropriate timing of excisional wound closure. We found that, unlike in WT mice, in Rhamm-null mice, keratinocyte migration initiates prematurely in the excisional wounds, resulting in wounds that have re-surfaced before the formation of normal granulation tissue, leading to a defective epidermal architecture. We also noted aberrant keratinocyte and fibroblast migration in the Rhamm-null mice, indicating that RHAMM suppresses keratinocyte motility but increases fibroblast motility. This cell context–dependent effect resulted from cell-specific regulation of extracellular signal-regulated kinase 1/2 (ERK1/2) activation and expression of a RHAMM target gene encoding matrix metalloprotease 9 (MMP-9). In fibroblasts, RHAMM promoted ERK1/2 activation and MMP-9 expression, whereas in keratinocytes, RHAMM suppressed these activities. In keratinocytes, loss of RHAMM function or expression promoted epidermal growth factor receptor–regulated MMP-9 expression via ERK1/2, which resulted in cleavage of the ectodomain of the RHAMM partner protein CD44 and thereby increased keratinocyte motility. These results identify RHAMM as a key factor that integrates the timing of wound repair by controlling cell migration. Full Article
ic Development of a novel {beta}-1,6-glucan-specific detection system using functionally-modified recombinant endo-{beta}-1,6-glucanase [Methods and Resources] By feedproxy.google.com Published On :: 2020-04-17T00:06:05-07:00 β-1,3-d-Glucan is a ubiquitous glucose polymer produced by plants, bacteria, and most fungi. It has been used as a diagnostic tool in patients with invasive mycoses via a highly-sensitive reagent consisting of the blood coagulation system of horseshoe crab. However, no method is currently available for measuring β-1,6-glucan, another primary β-glucan structure of fungal polysaccharides. Herein, we describe the development of an economical and highly-sensitive and specific assay for β-1,6-glucan using a modified recombinant endo-β-1,6-glucanase having diminished glucan hydrolase activity. The purified β-1,6-glucanase derivative bound to the β-1,6-glucan pustulan with a KD of 16.4 nm. We validated the specificity of this β-1,6-glucan probe by demonstrating its ability to detect cell wall β-1,6-glucan from both yeast and hyphal forms of the opportunistic fungal pathogen Candida albicans, without any detectable binding to glucan lacking the long β-1,6-glucan branch. We developed a sandwich ELISA-like assay with a low limit of quantification for pustulan (1.5 pg/ml), and we successfully employed this assay in the quantification of extracellular β-1,6-glucan released by >250 patient-derived strains of different Candida species (including Candida auris) in culture supernatant in vitro. We also used this assay to measure β-1,6-glucan in vivo in the serum and in several organs in a mouse model of systemic candidiasis. Our work describes a reliable method for β-1,6-glucan detection, which may prove useful for the diagnosis of invasive fungal infections. Full Article
ic Inter-{alpha}-inhibitor heavy chain-1 has an integrin-like 3D structure mediating immune regulatory activities and matrix stabilization during ovulation [Glycobiology and Extracellular Matrices] By feedproxy.google.com Published On :: 2020-04-17T00:06:05-07:00 Inter-α-inhibitor is a proteoglycan essential for mammalian reproduction and also plays a less well-characterized role in inflammation. It comprises two homologous “heavy chains” (HC1 and HC2) covalently attached to chondroitin sulfate on the bikunin core protein. Before ovulation, HCs are transferred onto the polysaccharide hyaluronan (HA) to form covalent HC·HA complexes, thereby stabilizing an extracellular matrix around the oocyte required for fertilization. Additionally, such complexes form during inflammatory processes and mediate leukocyte adhesion in the synovial fluids of arthritis patients and protect against sepsis. Here using X-ray crystallography, we show that human HC1 has a structure similar to integrin β-chains, with a von Willebrand factor A domain containing a functional metal ion-dependent adhesion site (MIDAS) and an associated hybrid domain. A comparison of the WT protein and a variant with an impaired MIDAS (but otherwise structurally identical) by small-angle X-ray scattering and analytical ultracentrifugation revealed that HC1 self-associates in a cation-dependent manner, providing a mechanism for HC·HA cross-linking and matrix stabilization. Surprisingly, unlike integrins, HC1 interacted with RGD-containing ligands, such as fibronectin, vitronectin, and the latency-associated peptides of transforming growth factor β, in a MIDAS/cation-independent manner. However, HC1 utilizes its MIDAS motif to bind to and inhibit the cleavage of complement C3, and small-angle X-ray scattering–based modeling indicates that this occurs through the inhibition of the alternative pathway C3 convertase. These findings provide detailed structural and functional insights into HC1 as a regulator of innate immunity and further elucidate the role of HC·HA complexes in inflammation and ovulation. Full Article
ic Glucocerebrosidases catalyze a transgalactosylation reaction that yields a newly-identified brain sterol metabolite, galactosylated cholesterol [Glycobiology and Extracellular Matrices] By feedproxy.google.com Published On :: 2020-04-17T00:06:05-07:00 β-Glucocerebrosidase (GBA) hydrolyzes glucosylceramide (GlcCer) to generate ceramide. Previously, we demonstrated that lysosomal GBA1 and nonlysosomal GBA2 possess not only GlcCer hydrolase activity, but also transglucosylation activity to transfer the glucose residue from GlcCer to cholesterol to form β-cholesterylglucoside (β-GlcChol) in vitro. β-GlcChol is a member of sterylglycosides present in diverse species. How GBA1 and GBA2 mediate β-GlcChol metabolism in the brain is unknown. Here, we purified and characterized sterylglycosides from rodent and fish brains. Although glucose is thought to be the sole carbohydrate component of sterylglycosides in vertebrates, structural analysis of rat brain sterylglycosides revealed the presence of galactosylated cholesterol (β-GalChol), in addition to β-GlcChol. Analyses of brain tissues from GBA2-deficient mice and GBA1- and/or GBA2-deficient Japanese rice fish (Oryzias latipes) revealed that GBA1 and GBA2 are responsible for β-GlcChol degradation and formation, respectively, and that both GBA1 and GBA2 are responsible for β-GalChol formation. Liquid chromatography–tandem MS revealed that β-GlcChol and β-GalChol are present throughout development from embryo to adult in the mouse brain. We found that β-GalChol expression depends on galactosylceramide (GalCer), and developmental onset of β-GalChol biosynthesis appeared to be during myelination. We also found that β-GlcChol and β-GalChol are secreted from neurons and glial cells in association with exosomes. In vitro enzyme assays confirmed that GBA1 and GBA2 have transgalactosylation activity to transfer the galactose residue from GalCer to cholesterol to form β-GalChol. This is the first report of the existence of β-GalChol in vertebrates and how β-GlcChol and β-GalChol are formed in the brain. Full Article
ic An enzyme-based protocol for cell-free synthesis of nature-identical capsular oligosaccharides from Actinobacillus pleuropneumoniae serotype 1 [Enzymology] By feedproxy.google.com Published On :: 2020-04-24T06:08:45-07:00 Actinobacillus pleuropneumoniae (App) is the etiological agent of acute porcine pneumonia and responsible for severe economic losses worldwide. The capsule polymer of App serotype 1 (App1) consists of [4)-GlcNAc-β(1,6)-Gal-α-1-(PO4-] repeating units that are O-acetylated at O-6 of the GlcNAc. It is a major virulence factor and was used in previous studies in the successful generation of an experimental glycoconjugate vaccine. However, the application of glycoconjugate vaccines in the animal health sector is limited, presumably because of the high costs associated with harvesting the polymer from pathogen culture. Consequently, here we exploited the capsule polymerase Cps1B of App1 as an in vitro synthesis tool and an alternative for capsule polymer provision. Cps1B consists of two catalytic domains, as well as a domain rich in tetratricopeptide repeats (TPRs). We compared the elongation mechanism of Cps1B with that of a ΔTPR truncation (Cps1B-ΔTPR). Interestingly, the product profiles displayed by Cps1B suggested processive elongation of the nascent polymer, whereas Cps1B-ΔTPR appeared to work in a more distributive manner. The dispersity of the synthesized products could be reduced by generating single-action transferases and immobilizing them on individual columns, separating the two catalytic activities. Furthermore, we identified the O-acetyltransferase Cps1D of App1 and used it to modify the polymers produced by Cps1B. Two-dimensional NMR analyses of the products revealed O-acetylation levels identical to those of polymer harvested from App1 culture supernatants. In conclusion, we have established a protocol for the pathogen-free in vitro synthesis of tailored, nature-identical App1 capsule polymers. Full Article
ic Glycation-mediated inter-protein cross-linking is promoted by chaperone-client complexes of {alpha}-crystallin: Implications for lens aging and presbyopia [Glycobiology and Extracellular Matrices] By feedproxy.google.com Published On :: 2020-04-24T06:08:45-07:00 Lens proteins become increasingly cross-linked through nondisulfide linkages during aging and cataract formation. One mechanism that has been implicated in this cross-linking is glycation through formation of advanced glycation end products (AGEs). Here, we found an age-associated increase in stiffness in human lenses that was directly correlated with levels of protein–cross-linking AGEs. α-Crystallin in the lens binds to other proteins and prevents their denaturation and aggregation through its chaperone-like activity. Using a FRET-based assay, we examined the stability of the αA-crystallin–γD-crystallin complex for up to 12 days and observed that this complex is stable in PBS and upon incubation with human lens–epithelial cell lysate or lens homogenate. Addition of 2 mm ATP to the lysate or homogenate did not decrease the stability of the complex. We also generated complexes of human αA-crystallin or αB-crystallin with alcohol dehydrogenase or citrate synthase by applying thermal stress. Upon glycation under physiological conditions, the chaperone–client complexes underwent greater extents of cross-linking than did uncomplexed protein mixtures. LC-MS/MS analyses revealed that the levels of cross-linking AGEs were significantly higher in the glycated chaperone–client complexes than in glycated but uncomplexed protein mixtures. Mouse lenses subjected to thermal stress followed by glycation lost resilience more extensively than lenses subjected to thermal stress or glycation alone, and this loss was accompanied by higher protein cross-linking and higher cross-linking AGE levels. These results uncover a protein cross-linking mechanism in the lens and suggest that AGE-mediated cross-linking of α-crystallin–client complexes could contribute to lens aging and presbyopia. Full Article
ic Processivity of dextransucrases synthesizing very-high-molar-mass dextran is mediated by sugar-binding pockets in domain V [Glycobiology and Extracellular Matrices] By feedproxy.google.com Published On :: 2020-04-24T06:08:45-07:00 The dextransucrase DSR-OK from the Gram-positive bacterium Oenococcus kitaharae DSM17330 produces a dextran of the highest molar mass reported to date (∼109 g/mol). In this study, we selected a recombinant form, DSR-OKΔ1, to identify molecular determinants involved in the sugar polymerization mechanism and that confer its ability to produce a very-high-molar-mass polymer. In domain V of DSR-OK, we identified seven putative sugar-binding pockets characteristic of glycoside hydrolase 70 (GH70) glucansucrases that are known to be involved in glucan binding. We investigated their role in polymer synthesis through several approaches, including monitoring of dextran synthesis, affinity assays, sugar binding pocket deletions, site-directed mutagenesis, and construction of chimeric enzymes. Substitution of only two stacking aromatic residues in two consecutive sugar-binding pockets (variant DSR-OKΔ1-Y1162A-F1228A) induced quasi-complete loss of very-high-molar-mass dextran synthesis, resulting in production of only 10–13 kg/mol polymers. Moreover, the double mutation completely switched the semiprocessive mode of DSR-OKΔ1 toward a distributive one, highlighting the strong influence of these pockets on enzyme processivity. Finally, the position of each pocket relative to the active site also appeared to be important for polymer elongation. We propose that sugar-binding pockets spatially closer to the catalytic domain play a major role in the control of processivity. A deep structural characterization, if possible with large-molar-mass sugar ligands, would allow confirming this hypothesis. Full Article
ic The Escherichia coli cellulose synthase subunit G (BcsG) is a Zn2+-dependent phosphoethanolamine transferase [Glycobiology and Extracellular Matrices] By feedproxy.google.com Published On :: 2020-05-01T00:06:09-07:00 Bacterial biofilms are cellular communities that produce an adherent matrix. Exopolysaccharides are key structural components of this matrix and are required for the assembly and architecture of biofilms produced by a wide variety of microorganisms. The human bacterial pathogens Escherichia coli and Salmonella enterica produce a biofilm matrix composed primarily of the exopolysaccharide phosphoethanolamine (pEtN) cellulose. Once thought to be composed of only underivatized cellulose, the pEtN modification present in these matrices has been implicated in the overall architecture and integrity of the biofilm. However, an understanding of the mechanism underlying pEtN derivatization of the cellulose exopolysaccharide remains elusive. The bacterial cellulose synthase subunit G (BcsG) is a predicted inner membrane–localized metalloenzyme that has been proposed to catalyze the transfer of the pEtN group from membrane phospholipids to cellulose. Here we present evidence that the C-terminal domain of BcsG from E. coli (EcBcsGΔN) functions as a phosphoethanolamine transferase in vitro with substrate preference for cellulosic materials. Structural characterization of EcBcsGΔN revealed that it belongs to the alkaline phosphatase superfamily, contains a Zn2+ ion at its active center, and is structurally similar to characterized enzymes that confer colistin resistance in Gram-negative bacteria. Informed by our structural studies, we present a functional complementation experiment in E. coli AR3110, indicating that the activity of the BcsG C-terminal domain is essential for integrity of the pellicular biofilm. Furthermore, our results established a similar but distinct active-site architecture and catalytic mechanism shared between BcsG and the colistin resistance enzymes. Full Article
ic Catabolic degradation of endothelial VEGFA via autophagy [Glycobiology and Extracellular Matrices] By feedproxy.google.com Published On :: 2020-05-01T00:06:09-07:00 Extracellular matrix-evoked angiostasis and autophagy within the tumor microenvironment represent two critical, but unconnected, functions of the small leucine-rich proteoglycan, decorin. Acting as a partial agonist of vascular endothelial growth factor 2 (VEGFR2), soluble decorin signals via the energy sensing protein, AMP-activated protein kinase (AMPK), in the autophagic degradation of intracellular vascular endothelial growth factor A (VEGFA). Here, we discovered that soluble decorin evokes intracellular catabolism of endothelial VEGFA that is mechanistically independent of mTOR, but requires an autophagic regulator, paternally expressed gene 3 (PEG3). We found that administration of autophagic inhibitors such as chloroquine or bafilomycin A1, or depletion of autophagy-related 5 (ATG5), results in accumulation of intracellular VEGFA, indicating that VEGFA is a basal autophagic substrate. Mechanistically, decorin increased the VEGFA clearance rate by augmenting autophagic flux, a process that required RAB24 member RAS oncogene family (RAB24), a small GTPase that facilitates the disposal of autophagic compartments. We validated these findings by demonstrating the physiological relevance of this process in vivo. Mice starved for 48 h exhibited a sharp decrease in overall cardiac and aortic VEGFA that could be blocked by systemic chloroquine treatment. Thus, our findings reveal a unified mechanism for the metabolic control of endothelial VEGFA for autophagic clearance in response to decorin and canonical pro-autophagic stimuli. We posit that the VEGFR2/AMPK/PEG3 axis integrates the anti-angiogenic and pro-autophagic bioactivities of decorin as the molecular basis for tumorigenic suppression. These results support future therapeutic use of decorin as a next-generation protein therapy to combat cancer. Full Article
ic Inhibition of glycosphingolipid biosynthesis reverts multidrug resistance by differentially modulating ABC transporters in chronic myeloid leukemias [Cell Biology] By feedproxy.google.com Published On :: 2020-05-08T03:41:14-07:00 Multidrug resistance (MDR) in cancer arises from cross-resistance to structurally- and functionally-divergent chemotherapeutic drugs. In particular, MDR is characterized by increased expression and activity of ATP-binding cassette (ABC) superfamily transporters. Sphingolipids are substrates of ABC proteins in cell signaling, membrane biosynthesis, and inflammation, for example, and their products can favor cancer progression. Glucosylceramide (GlcCer) is a ubiquitous glycosphingolipid (GSL) generated by glucosylceramide synthase, a key regulatory enzyme encoded by the UDP-glucose ceramide glucosyltransferase (UGCG) gene. Stressed cells increase de novo biosynthesis of ceramides, which return to sub-toxic levels after UGCG mediates incorporation into GlcCer. Given that cancer cells seem to mobilize UGCG and have increased GSL content for ceramide clearance, which ultimately contributes to chemotherapy failure, here we investigated how inhibition of GSL biosynthesis affects the MDR phenotype of chronic myeloid leukemias. We found that MDR is associated with higher UGCG expression and with a complex GSL profile. UGCG inhibition with the ceramide analog d-threo-1-(3,4,-ethylenedioxy)phenyl-2-palmitoylamino-3-pyrrolidino-1-propanol (EtDO-P4) greatly reduced GSL and monosialotetrahexosylganglioside levels, and co-treatment with standard chemotherapeutics sensitized cells to mitochondrial membrane potential loss and apoptosis. ABC subfamily B member 1 (ABCB1) expression was reduced, and ABCC-mediated efflux activity was modulated by competition with nonglycosylated ceramides. Consistently, inhibition of ABCC-mediated transport reduced the efflux of exogenous C6-ceramide. Overall, UGCG inhibition impaired the malignant glycophenotype of MDR leukemias, which typically overcomes drug resistance through distinct mechanisms. This work sheds light on the involvement of GSL in chemotherapy failure, and its findings suggest that targeted GSL modulation could help manage MDR leukemias. Full Article
ic Endorepellin evokes an angiostatic stress signaling cascade in endothelial cells [Glycobiology and Extracellular Matrices] By feedproxy.google.com Published On :: 2020-05-08T03:41:14-07:00 Endorepellin, the C-terminal fragment of the heparan sulfate proteoglycan perlecan, influences various signaling pathways in endothelial cells by binding to VEGFR2. In this study, we discovered that soluble endorepellin activates the canonical stress signaling pathway consisting of PERK, eIF2α, ATF4, and GADD45α. Specifically, endorepellin evoked transient activation of VEGFR2, which, in turn, phosphorylated PERK at Thr980. Subsequently, PERK phosphorylated eIF2α at Ser51, upregulating its downstream effector proteins ATF4 and GADD45α. RNAi-mediated knockdown of PERK or eIF2α abrogated the endorepellin-mediated up-regulation of GADD45α, the ultimate effector protein of this stress signaling cascade. To functionally validate these findings, we utilized an ex vivo model of angiogenesis. Exposure of the aortic rings embedded in 3D fibrillar collagen to recombinant endorepellin for 2–4 h activated PERK and induced GADD45α vis à vis vehicle-treated counterparts. Similar effects were obtained with the established cellular stress inducer tunicamycin. Notably, chronic exposure of aortic rings to endorepellin for 7–9 days markedly suppressed vessel sprouting, an angiostatic effect that was rescued by blocking PERK kinase activity. Our findings unravel a mechanism by which an extracellular matrix protein evokes stress signaling in endothelial cells, which leads to angiostasis. Full Article
ic Re: Face masks for the public during the covid-19 crisis By feeds.bmj.com Published On :: Friday, May 8, 2020 - 20:15 Full Article
ic Classifying deaths from COVID-19: Why the official statistics will never reflect the true mortality from coronavirus, and how future studies could try to address this By feeds.bmj.com Published On :: Friday, May 8, 2020 - 21:11 Full Article
ic Covid-19: underneath the iceberg By feeds.bmj.com Published On :: Saturday, May 9, 2020 - 05:45 Full Article
ic Re: Clinical features of covid-19 By feeds.bmj.com Published On :: Saturday, May 9, 2020 - 09:36 Full Article
ic Re: Covid-19: how to use your time when clinical placements are postponed - Wellbeing perspective By feeds.bmj.com Published On :: Saturday, May 9, 2020 - 13:41 Full Article
ic The multi-ness of fighting the short-term and long-term consequences of the COVID-19 pandemic By feeds.bmj.com Published On :: Saturday, May 9, 2020 - 16:58 Full Article
ic Re: Prognosis of unrecognised myocardial infarction determined by electrocardiography or cardiac magnetic resonance imaging: systematic review and meta-analysis By feeds.bmj.com Published On :: Saturday, May 9, 2020 - 18:01 Full Article
ic Call for a review of services for people with neurological disorders By feeds.bmj.com Published On :: Tuesday, August 11, 2015 - 15:35 Full Article
ic A real opportunity to improve neurology services in England By feeds.bmj.com Published On :: Tuesday, August 11, 2015 - 15:56 Full Article
ic Rising drug prices drive US manufacturers’ revenues, analysis finds By feeds.bmj.com Published On :: Wednesday, October 7, 2015 - 10:46 Full Article
ic US drug costs are rising faster than overall health spending, officials report By feeds.bmj.com Published On :: Friday, March 11, 2016 - 11:26 Full Article
ic Environment may play significant role in multiple sclerosis By feeds.bmj.com Published On :: Monday, March 21, 2016 - 06:30 Full Article
ic US drug makers have imposed big price rises for top selling drugs, study finds By feeds.bmj.com Published On :: Tuesday, April 5, 2016 - 14:01 Full Article
ic Health anxiety: the silent, disabling epidemic By feeds.bmj.com Published On :: Monday, April 25, 2016 - 10:01 Full Article
ic Seven days in medicine: 8-14 June 2016 By feeds.bmj.com Published On :: Thursday, June 16, 2016 - 23:16 Full Article
ic The Faltering U.S. Refugee Protection System: Legal and Policy Responses to Refugees, Asylum Seekers, and Others in Need of Protection By www.migrationpolicy.org Published On :: Sun, 01 May 2011 00:00:00 -0400 The U.S. refugee protection system, while generous in many respects, has become less robust over the last two decades. The unique and often diverse needs of emerging refugee populations have exposed severe limitations in the standard resettlement approach.This report examines U.S. legal and policy responses to those seeking protection and addresses the barriers, gaps, and opportunities that exist. Full Article
ic Policies to Curb Unauthorized Employment By www.migrationpolicy.org Published On :: Sun, 01 May 2011 00:00:00 -0400 Illegal immigration is possible in large part because of illegal employment. This report shows the underlying drivers of illegal hiring vary based on the type of employer, the nature of the industry, state of the economy, and a country’s labor market institutions, employment legislation, immigration systems, and even culture. Full Article
ic Eight Policies to Boost the Economic Contribution of Employment-Based Immigration By www.migrationpolicy.org Published On :: Wed, 01 Jun 2011 00:00:00 -0400 Drawing on experiences from Asia, Europe, North America, and the Pacific region, this report presents eight strategies that represent best practices developed by immigrant-receiving countries to increase the economic contributions of immigration. Full Article
ic Migration and Development: Policy Perspectives from the United States By www.migrationpolicy.org Published On :: Wed, 01 Jun 2011 00:00:00 -0400 The report examines U.S. immigration and international development policies, which have unique objectives and respond to distinct political and administrative constraints, and points out that international development has never been a U.S. immigration policy objective; nonetheless, it is an unintended consequence. Full Article
ic Emerging Transatlantic Security Dilemmas in Border Management By www.migrationpolicy.org Published On :: Wed, 01 Jun 2011 00:00:00 -0400 The exponential growth of international travel since the 1960s has left border management systems worldwide struggling to keep up and has exposed weaknesses in states’ abilities to effectively manage their borders, especially regarding terrorist attacks, human trafficking, and illegal migration. Full Article
ic New Streams: Black African Migration to the United States By www.migrationpolicy.org Published On :: Wed, 01 Jun 2011 00:00:00 -0400 This report explores the migration patterns and demographics of Black African immigrants in the United States, examining their admission channels, human-capital characteristics, and labor market performance. The authors also provide an analysis of these immigrants' integration prospects. Full Article
ic Opportunities for Transatlantic Cooperation on International Migration By www.migrationpolicy.org Published On :: Wed, 01 Jun 2011 00:00:00 -0400 The EU-U.S. relationship is one of the most significant partnerships among wealthy nations. Interconnections between the two on migration issues make dialogue necessary and inevitable, as each relies on each other to attain a number of policy objectives, most clearly in the case of travel and border security. Full Article
ic The Role of Civil Society in EU Migration Policy: Perspectives on the European Union's Engagement in its Neighborhood By www.migrationpolicy.org Published On :: Wed, 01 Jun 2011 00:00:00 -0400 Civil society provides a crucial link between governments and the communities they represent—infusing policy processes with grassroots knowledge to which governments may not otherwise have access. Looking at the European Union’s efforts to engage with civil society in its “neighborhood,” this report examines the benefits, challenges, and mechanisms to building dialogue and cooperation on migration and development. Full Article
ic Mexican and Central American Immigrants in the United States By www.migrationpolicy.org Published On :: Wed, 01 Jun 2011 00:00:00 -0400 Since 1970, the immigrant populations from Mexico and Central America living in the United States have increased significantly: rising by a factor of 20 even as the total U.S. immigrant population increased four-fold over the period. This demographic report examines the age, educational, and workforce characteristics of these immigrants. Full Article
ic The Economic Integration of Immigrants in the United States: Long- and Short-Term Perspectives By www.migrationpolicy.org Published On :: Fri, 01 Jul 2011 00:00:00 -0400 The United States has historically offered unparalleled economic opportunity to successive generations of immigrants and their children, poised to play an increasing role in the U.S. economy. But the lasting impact of job loss and slower growth over the next decade will translate into fewer opportunities for workers—and immigrants may prove the most vulnerable. Full Article
ic Shared Challenges and Opportunities for EU and U.S. Immigration Policymakers By www.migrationpolicy.org Published On :: Sat, 01 Oct 2011 00:00:00 -0400 This final report summarizes and reflects upon the key findings of the Improving EU and U.S. Immigration Systems: Learning from Experience comparative research project undertaken by MPI and the European University Institute through a grant from the European Commission. Full Article
ic Migration and Development Policy: What Have We Learned? By www.migrationpolicy.org Published On :: Sat, 01 Oct 2011 00:00:00 -0400 Migration and development have emerged as a pressing policy priority on the global agenda. This report identifies critical lessons from the past decade of policy experimentation and offers recommendations for migration and development policy. Full Article
ic Cricket legend Murray warns against hasty restart By jamaica-gleaner.com Published On :: Sun, 10 May 2020 00:06:34 -0500 BRIDGETOWN, Barbados (CMC): Former top West Indies cricket administrator, 76-year-old Deryck Murray, has warned against a forced restart of cricket amid the current challenges posed by the deadly coronavirus pandemic, and says any premature actions... Full Article
ic Big blow for former Sunshine Girl - Registered Nurse Nichala Gibson recovered from COVID-19 but her father was not so lucky By jamaica-gleaner.com Published On :: Sun, 10 May 2020 00:32:12 -0500 THE LAST two months have been two of the worst in the life of former national netball star Nichala Gibson. She lives in New York City, the epicentre for the COVID-19 virus in the United States. Gibson and her sister suffered, then recovered from... Full Article
ic #JamaicaTogether | Portia Simpson Miller By jamaica-gleaner.com Published On :: Sun, 10 May 2020 00:16:51 -0500 As daunting as this COVID-19 pandemic has proven to be, and as devastating as its impact is on people both here at home and around the world, we must stand together, united. We must all act with purpose, resolve, love and compassion because when we... Full Article
ic Daddy, when are you coming home? - Stranded Jamaican cruise ship worker dreads Mother’s Day away from family By jamaica-gleaner.com Published On :: Sun, 10 May 2020 00:26:51 -0500 For drummer Conroy Gordon, the hardest part of being locked away day after day in the narrow confines of a stranded cruise ship is his inability to tell his two daughters when Daddy will be home. For the past month, he has been battling this... Full Article
ic Changing Demography and Circumstances for Young Black Children in African and Caribbean Immigrant Families By www.migrationpolicy.org Published On :: Sun, 01 Apr 2012 00:00:00 -0400 This report finds that the 813,000 U.S. children under the age of 10 who have Black immigrant parents from Africa or the Caribbean generally fall in the middle of multiple well-being indicators, faring less well than Asian and white children but better than their native-born Black and Hispanic peers. Citizenship status, English proficiency, parental characteristics, poverty, housing, and access to social supports are examined. Full Article
ic A Demographic Profile of Black Caribbean Immigrants in the United States By www.migrationpolicy.org Published On :: Sun, 01 Apr 2012 00:00:00 -0400 Immigration from the Caribbean to the United States is a relatively recent phenomenon, beginning largely after 1965. This report provides a demographic profile of the 1.7 million Caribbean immigrants in the United States: their geographic settlement, education and workforce characteristics, earnings, modes of entry, and more. Full Article
ic Diverse Streams: African Migration to the United States By www.migrationpolicy.org Published On :: Sun, 01 Apr 2012 00:00:00 -0400 African immigrants generally fare well on integration indicators, with college completion rates that greatly exceed those for most other immigrant groups and U.S. natives, this report finds. The United States, Canada, and Australia disproportionally attract better-educated African migrants then do the United Kingdom, France, and other European countries. Full Article
ic Black and Immigrant: Exploring the Effects of Ethnicity and Foreign-Born Status on Infant Health By www.migrationpolicy.org Published On :: Sat, 01 Sep 2012 00:00:00 -0400 This report analyzes prenatal behaviors and birth outcomes of Black immigrant mothers, and finds that Black immigrant mothers are less likely to give birth to preterm or low-birth-weight infants than U.S.-born Black women, but more likely to experience these birth outcomes than other immigrant and U.S.-born women. Full Article