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Problem Notes for SAS®9 - 66500: A content release on the SAS Risk Governance Framework fails to load when you use SAS 9.4M7 (TS1M7) on the Microsoft Windows operating system

When you log on to the SAS Risk Governance Framework and choose a solution, the web application might fail to load the solution content. When the problem occurs, you continue to see "Loading..." on the screen, an




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Problem Notes for SAS®9 - 66294: The SAS Federation Server SPD driver fails to create a table that has a column name in UTF-8 encoding that also contains Latin5 characters

Certain tables that are created in SAS Scalable Performance Data (SPD) Server might not be displayed correctly by SAS Federation Server Manager. Tables that have Latin5 characters in column names encounter this




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Docosanoid signaling modulates corneal nerve regeneration: effect on tear secretion, wound healing, and neuropathic pain [Thematic Reviews]

The cornea is densely innervated, mainly by sensory nerves of the ophthalmic branch of the trigeminal ganglia (TG). These nerves  are important to maintain corneal homeostasis, and nerve damage can lead to a decrease in wound healing, an increase in corneal ulceration and dry eye disease (DED), and neuropathic pain. Pathologies, such as diabetes, aging, viral and bacterial infection, as well as  prolonged use of contact lenses and surgeries to correct vision can produce nerve damage. There are no effective therapies to alleviate DED (a multifunctional disease) and several clinical trials using -3 supplementation show unclear and sometimes negative results. Using animal models of corneal nerve damage, we show that treating corneas with pigment epithelium-derived factor (PEDF) plus docosahexaenoic acid (DHA) increases nerve regeneration, wound healing, and tear secretion. The mechanism involves the activation of a calcium-independent phospholipase A2 (iPLA2) that releases the incorporated DHA from phospholipids and enhances the synthesis of docosanoids neuroprotectin D1 (NPD1) and a new resolvin stereoisomer  RvD6i. NPD1 stimulates the synthesis of brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), and of semaphorin 7A (Sema7A).  RvD6i treatment of injured corneas modulates gene expression in the TG resulting in enhanced neurogenesis; decreased neuropathic pain and increased sensitivity. Taken together, these results represent a promising therapeutic option to re-establish the homeostasis of the cornea.




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Cholesterol homeostasis in the vertebrate retina: Biology and pathobiology [Thematic Reviews]

Cholesterol is a quantitatively and biologically significant constituent of all mammalian cell membrane, including those that comprise the retina. Retinal cholesterol homeostasis entails the interplay between de novo synthesis, uptake, intra-retinal sterol transport, metabolism and efflux. Defects in these complex processes are associated with several congenital and age-related disorders of the visual system. Herein, we provide an overview of the following topics: a) cholesterol synthesis in the neural retina; b) lipoprotein uptake and intraretinal sterol transport in the neural retina and the retinal pigment epithelium (RPE); c) cholesterol efflux from the neural retina and the RPE; and d) biology and pathobiology of defects in sterol synthesis and sterol oxidation in the neural retina and the RPE. We focus, in particular, on studies involving animal models of monogenic disorders pertinent to the above topics, as well as in vitro models using biochemical, metabolic, and omic approaches. We also identify current knowledge gaps as well as opportunities in the field that beg further research in this topic area.




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Generation and validation of a conditional knockout mouse model for the study of the Smith-Lemli-Opitz Syndrome [Research Articles]

Smith-Lemli-Opitz Syndrome (SLOS) is a developmental disorder (OMIM #270400) caused by autosomal recessive mutations in the Dhcr7 gene, which encodes the enzyme 3β-hydroxysterol-7 reductase. SLOS patients present clinically with dysmorphology and neurological, behavioral and cognitive defects, with characteristically elevated levels of 7-dehydrocholesterol (7-DHC) in all bodily tissues and fluids. Previous mouse models of SLOS have been hampered by postnatal lethality when Dhcr7 is knocked out globally, while a hypomorphic mouse model showed improvement in the biochemical phenotype with ageing, and did not manifest most other characteristic features of SLOS. We report the generation of a conditional knockout of Dhcr7 (Dhcr7flx/flx), validated by generating a mouse with a liver-specific deletion (Dhcr7L-KO). Phenotypic characterization of liver-specific knockout mice revealed no significant changes in viability, fertility, growth curves, liver architecture, hepatic triglyceride secretion, or parameters of systemic glucose homeostasis. Furthermore, qPCR and RNA-Seq analyses of livers revealed no perturbations in pathways responsible for cholesterol synthesis, either in male or female Dhcr7L-KO mice, suggesting hepatic disruption of post-squalene cholesterol synthesis leads to minimal impact on sterol metabolism in the liver. This validated conditional Dhcr7 knockout model may now allow us to systematically explore the pathophysiology of SLOS, by allowing for temporal, cell and tissue-specific loss of DHCR7.




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Supervised physiotherapy for mild or moderate ankle sprain




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Generation and characterization of LPA-KIV9, a murine monoclonal antibody binding a single site on apolipoprotein (a) [Research Articles]

Lipoprotein (a) [Lp(a)] is a risk factor for CVD and a target of therapy, but Lp(a) measurements are not globally standardized. Commercially available assays generally use polyclonal antibodies that detect multiple sites within the kringle (K)IV2 repeat region of Lp(a) and may lead to inaccurate assessments of plasma levels. With increasing awareness of Lp(a) as a cardiovascular risk factor and the active clinical development of new potential therapeutic approaches, the broad availability of reagents capable of providing isoform independence of Lp(a) measurements is paramount. To address this issue, we generated a murine monoclonal antibody that binds to only one site on apo(a). A BALB/C mouse was immunized with a truncated version of apo(a) that contained eight total KIV repeats, including only one copy of KIV2. We generated hybridomas, screened them, and successfully produced a KIV2-independent monoclonal antibody, named LPA-KIV9. Using a variety of truncated apo(a) constructs to map its binding site, we found that LPA-KIV9 binds to KIV9 without binding to plasminogen. Fine peptide mapping revealed that LPA-KIV9 bound to the sequence 4076LETPTVV4082 on KIV9. In conclusion, the generation of monoclonal antibody LPA-KIV9 may be a useful reagent in basic research studies and in the clinical application of Lp(a) measurements.




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Different rates of flux through the biosynthetic pathway for long-chain versus very-long-chain sphingolipids [Research Articles]

The backbone of all sphingolipids (SLs) is a sphingoid long-chain base (LCB) to which a fatty acid is N-acylated. Considerable variability exists in the chain length and degree of saturation of both of these hydrophobic chains, and recent work has implicated ceramides with different LCBs and N-acyl chains in distinct biological processes; moreover, they may play different roles in disease states and possibly even act as prognostic markers. We now demonstrate that the half-life, or turnover rate, of ceramides containing diverse N-acyl chains is different. By means of a pulse-labeling protocol using stable-isotope, deuterated free fatty acids, and following their incorporation into ceramide and downstream SLs, we show that very-long-chain (VLC) ceramides containing C24:0 or C24:1 fatty acids turn over much more rapidly than long-chain (LC) ceramides containing C16:0 or C18:0 fatty acids due to the more rapid metabolism of the former into VLC sphingomyelin and VLC hexosylceramide. In contrast, d16:1 and d18:1 ceramides show similar rates of turnover, indicating that the length of the sphingoid LCB does not influence the flux of ceramides through the biosynthetic pathway. Together, these data demonstrate that the N-acyl chain length of SLs may not only affect membrane biophysical properties but also influence the rate of metabolism of SLs so as to regulate their levels and perhaps their biological functions.




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Harmonized procedures lead to comparable quantification of total oxylipins across laboratories [Research Articles]

Oxylipins are potent lipid mediators involved in a variety of physiological processes. Their profiling has the potential to provide a wealth of information regarding human health and disease and is a promising technology for translation into clinical applications. However, results generated by independent groups are rarely comparable, which increases the need for the implementation of internationally agreed upon protocols. We performed an interlaboratory comparison for the MS-based quantitative analysis of total oxylipins. Five independent laboratories assessed the technical variability and comparability of 133 oxylipins using a harmonized and standardized protocol, common biological materials (i.e., seven quality control plasmas), standard calibration series, and analytical methods. The quantitative analysis was based on a standard calibration series with isotopically labeled internal standards. Using the standardized protocol, the technical variance was within ±15% for 73% of oxylipins; however, most epoxy fatty acids were identified as critical analytes due to high variabilities in concentrations. The comparability of concentrations determined by the laboratories was examined using consensus value estimates and unsupervised/supervised multivariate analysis (i.e., principal component analysis and partial least squares discriminant analysis). Interlaboratory variability was limited and did not interfere with our ability to distinguish the different plasmas. Moreover, all laboratories were able to identify similar differences between plasmas. In summary, we show that by using a standardized protocol for sample preparation, low technical variability can be achieved. Harmonization of all oxylipin extraction and analysis steps led to reliable, reproducible, and comparable oxylipin concentrations in independent laboratories, allowing the generation of biologically meaningful oxylipin patterns.




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Bioavailability and spatial distribution of fatty acids in the rat retina after dietary omega-3 supplementation [Research Articles]

Spatial changes of FAs in the retina in response to different dietary n-3 formulations have never been explored, although a diet rich in EPA and DHA is recommended to protect the retina against the effects of aging. In this study, Wistar rats were fed for 8 weeks with balanced diet including either EPA-containing phospholipids (PLs), EPA-containing TGs, DHA-containing PLs, or DHA-containing TGs. Qualitative changes in FA composition of plasma, erythrocytes, and retina were evaluated by gas chromatography-flame ionization detector. Following the different dietary intakes, changes to the quantity and spatial organization of PC and PE species in retina were determined by LC coupled to MS/MS and MALDI coupled to MS imaging. The omega-3 content in the lipids of plasma and erythrocytes suggests that PLs as well as TGs are good omega-3 carriers for retina. However, a significant increase in DHA content in retina was observed, especially molecular species as di-DHA-containing PC and PE, as well as an increase in very long chain PUFAs (more than 28 carbons) following PL-EPA and TG-DHA diets only. All supplemented diets triggered spatial organization changes of DHA in the photoreceptor layer around the optic nerve. Taken together, these findings suggest that dietary omega-3 supplementation can modify the content of FAs in the rat retina.




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Solvent accessibility changes in a Na+-dependent C4-dicarboxylate transporter suggest differential substrate effects in a multistep mechanism [Membrane Biology]

The divalent anion sodium symporter (DASS) family (SLC13) plays critical roles in metabolic homeostasis, influencing many processes, including fatty acid synthesis, insulin resistance, and adiposity. DASS transporters catalyze the Na+-driven concentrative uptake of Krebs cycle intermediates and sulfate into cells; disrupting their function can protect against age-related metabolic diseases and can extend lifespan. An inward-facing crystal structure and an outward-facing model of a bacterial DASS family member, VcINDY from Vibrio cholerae, predict an elevator-like transport mechanism involving a large rigid body movement of the substrate-binding site. How substrate binding influences the conformational state of VcINDY is currently unknown. Here, we probe the interaction between substrate binding and protein conformation by monitoring substrate-induced solvent accessibility changes of broadly distributed positions in VcINDY using a site-specific alkylation strategy. Our findings reveal that accessibility to all positions tested is modulated by the presence of substrates, with the majority becoming less accessible in the presence of saturating concentrations of both Na+ and succinate. We also observe separable effects of Na+ and succinate binding at several positions suggesting distinct effects of the two substrates. Furthermore, accessibility changes to a solely succinate-sensitive position suggests that substrate binding is a low-affinity, ordered process. Mapping these accessibility changes onto the structures of VcINDY suggests that Na+ binding drives the transporter into an as-yet-unidentified conformational state, involving rearrangement of the substrate-binding site–associated re-entrant hairpin loops. These findings provide insight into the mechanism of VcINDY, which is currently the only structurally characterized representative of the entire DASS family.




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Exofacial membrane composition and lipid metabolism regulates plasma membrane P4-ATPase substrate specificity [Lipids]

The plasma membrane of a cell is characterized by an asymmetric distribution of lipid species across the exofacial and cytofacial aspects of the bilayer. Regulation of membrane asymmetry is a fundamental characteristic of membrane biology and is crucial for signal transduction, vesicle transport, and cell division. The type IV family of P-ATPases, or P4-ATPases, establishes membrane asymmetry by selection and transfer of a subset of membrane lipids from the lumenal or exofacial leaflet to the cytofacial aspect of the bilayer. It is unclear how P4-ATPases sort through the spectrum of membrane lipids to identify their desired substrate(s) and how the membrane environment modulates this activity. Therefore, we tested how the yeast plasma membrane P4-ATPase, Dnf2, responds to changes in membrane composition induced by perturbation of endogenous lipid biosynthetic pathways or exogenous application of lipid. The primary substrates of Dnf2 are glucosylceramide (GlcCer) and phosphatidylcholine (PC, or their lyso-lipid derivatives), and we find that these substrates compete with each other for transport. Acutely inhibiting sphingolipid synthesis using myriocin attenuates transport of exogenously applied GlcCer without perturbing PC transport. Deletion of genes controlling later steps of glycosphingolipid production also perturb GlcCer transport to a greater extent than PC transport. In contrast, perturbation of ergosterol biosynthesis reduces PC and GlcCer transport equivalently. Surprisingly, application of lipids that are poor transport substrates differentially affects PC and GlcCer transport by Dnf2, thus altering substrate preference. Our data indicate that Dnf2 exhibits exquisite sensitivity to the membrane composition, thus providing feedback onto the function of the P4-ATPases.




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Accurate MS-based Rab10 Phosphorylation Stoichiometry Determination as Readout for LRRK2 Activity in Parkinson's Disease [Research]

Pathogenic mutations in the Leucine-rich repeat kinase 2 (LRRK2) are the predominant genetic cause of Parkinson's disease (PD). They increase its activity, resulting in augmented Rab10-Thr73 phosphorylation and conversely, LRRK2 inhibition decreases pRab10 levels. Currently, there is no assay to quantify pRab10 levels for drug target engagement or patient stratification. To meet this challenge, we developed an high accuracy and sensitivity targeted mass spectrometry (MS)-based assay for determining Rab10-Thr73 phosphorylation stoichiometry in human samples. It uses synthetic stable isotope-labeled (SIL) analogues for both phosphorylated and nonphosphorylated tryptic peptides surrounding Rab10-Thr73 to directly derive the percentage of Rab10 phosphorylation from attomole amounts of the endogenous phosphopeptide. The SIL and the endogenous phosphopeptides are separately admitted into an Orbitrap analyzer with the appropriate injection times. We test the reproducibility of our assay by determining Rab10-Thr73 phosphorylation stoichiometry in neutrophils of LRRK2 mutation carriers before and after LRRK2 inhibition. Compared with healthy controls, the PD predisposing mutation carriers LRRK2 G2019S and VPS35 D620N display 1.9-fold and 3.7-fold increased pRab10 levels, respectively. Our generic MS-based assay further establishes the relevance of pRab10 as a prognostic PD marker and is a powerful tool for determining LRRK2 inhibitor efficacy and for stratifying PD patients for LRRK2 inhibitor treatment.




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The Insulin Receptor Adaptor IRS2 is an APC/C Substrate That Promotes Cell Cycle Protein Expression and a Robust Spindle Assembly Checkpoint [Research]

Insulin receptor substrate 2 (IRS2) is an essential adaptor that mediates signaling downstream of the insulin receptor and other receptor tyrosine kinases. Transduction through IRS2-dependent pathways is important for coordinating metabolic homeostasis, and dysregulation of IRS2 causes systemic insulin signaling defects. Despite the importance of maintaining proper IRS2 abundance, little is known about what factors mediate its protein stability. We conducted an unbiased proteomic screen to uncover novel substrates of the Anaphase Promoting Complex/Cyclosome (APC/C), a ubiquitin ligase that controls the abundance of key cell cycle regulators. We found that IRS2 levels are regulated by APC/C activity and that IRS2 is a direct APC/C target in G1. Consistent with the APC/C's role in degrading cell cycle regulators, quantitative proteomic analysis of IRS2-null cells revealed a deficiency in proteins involved in cell cycle progression. We further show that cells lacking IRS2 display a weakened spindle assembly checkpoint in cells treated with microtubule inhibitors. Together, these findings reveal a new pathway for IRS2 turnover and indicate that IRS2 is a component of the cell cycle control system in addition to acting as an essential metabolic regulator.




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Depolarization-dependent Induction of Site-specific Changes in Sialylation on N-linked Glycoproteins in Rat Nerve Terminals [Research]

Synaptic transmission leading to release of neurotransmitters in the nervous system is a fast and highly dynamic process. Previously, protein interaction and phosphorylation have been thought to be the main regulators of synaptic transmission. Here we show that sialylation of N-linked glycosylation is a novel potential modulator of neurotransmitter release mechanisms by investigating depolarization-dependent changes of formerly sialylated N-linked glycopeptides. We suggest that negatively charged sialic acids can be modulated, similarly to phosphorylation, by the action of sialyltransferases and sialidases thereby changing local structure and function of membrane glycoproteins. We characterized site-specific alteration in sialylation on N-linked glycoproteins in isolated rat nerve terminals after brief depolarization using quantitative sialiomics. We identified 1965 formerly sialylated N-linked glycosites in synaptic proteins and found that the abundances of 430 glycosites changed after 5 s depolarization. We observed changes on essential synaptic proteins such as synaptic vesicle proteins, ion channels and transporters, neurotransmitter receptors and cell adhesion molecules. This study is to our knowledge the first to describe ultra-fast site-specific modulation of the sialiome after brief stimulation of a biological system.




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Correction: Concentration Determination of >200 Proteins in Dried Blood Spots for Biomarker Discovery and Validation [Addition and Correction]




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Novel Proteome Extraction Method Illustrates a Conserved Immunological Signature of MSI-H Colorectal Tumors [Research]

Using a simple, environment friendly proteome extraction (TOP), we were able to optimize the analysis of clinical samples. Using our TOP method we analyzed a clinical cohort of microsatellite stable (MSS) and unstable (MSI-H) colorectal carcinoma (CRC). We identified a tumor cell specific, STAT1-centered, immune signature expressed by the MSI-H tumor cells. We then showed that long, but not short, exposure to Interferon- induces a similar signature in vitro. We identified 10 different temporal protein expression patterns, classifying the Interferon- protein temporal regulation in CRC. Our data sheds light on the changes that tumor cells undergo under long-term immunological pressure in vivo, the importance of STAT proteins in specific biological scenarios. The data generated could help find novel clinical biomarkers and therapeutic approaches.




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Glutathionylation Decreases Methyltransferase Activity of PRMT5 and Inhibits Cell Proliferation [Research]

Glutathionylation is an important posttranslational modification that protects proteins from further oxidative damage as well as influencing protein structure and activity. In the present study, we demonstrate that the cysteine-42 residue in protein arginine N-methyltransferase 5 (PRMT5) is glutathionylated in aged mice or in cells that have been exposed to oxidative stress. Deglutathionylation of this protein is catalyzed by glutaredoxin-1 (Grx1). Using mutagenesis and subsequent biochemical analyses, we show that glutathionylation decreased the binding affinity of PRMT5 with methylosome protein-50 (MEP50) and reduced the methyltransferase activity of PRMT5. Furthermore, overexpression of PRMT5-C42A mutant caused a significant increase in histone methylation in HEK293T and A549 cells and promoted cell growth, whereas overexpression of the PRMT5-C42D mutant, a mimic of glutathionylated PRMT5, inhibited cell proliferation. Taken together, our results demonstrate a new mechanism of regulation of PRMT5 methyltransferases activity and suggest that PRMT5 glutathionylation is partly responsible for reactive oxygen species-mediated cell growth inhibition.




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The Capture of a Disabled Proteasome Identifies Erg25 as a Substrate for Endoplasmic Reticulum Associated Degradation [Research]

Studies in the yeast Saccharomyces cerevisiae have helped define mechanisms underlying the activity of the ubiquitin–proteasome system (UPS), uncover the proteasome assembly pathway, and link the UPS to the maintenance of cellular homeostasis. However, the spectrum of UPS substrates is incompletely defined, even though multiple techniques—including MS—have been used. Therefore, we developed a substrate trapping proteomics workflow to identify previously unknown UPS substrates. We first generated a yeast strain with an epitope tagged proteasome subunit to which a proteasome inhibitor could be applied. Parallel experiments utilized inhibitor insensitive strains or strains lacking the tagged subunit. After affinity isolation, enriched proteins were resolved, in-gel digested, and analyzed by high resolution liquid chromatography-tandem MS. A total of 149 proteasome partners were identified, including all 33 proteasome subunits. When we next compared data between inhibitor sensitive and resistant cells, 27 proteasome partners were significantly enriched. Among these proteins were known UPS substrates and proteins that escort ubiquitinated substrates to the proteasome. We also detected Erg25 as a high-confidence partner. Erg25 is a methyl oxidase that converts dimethylzymosterol to zymosterol, a precursor of the plasma membrane sterol, ergosterol. Because Erg25 is a resident of the endoplasmic reticulum (ER) and had not previously been directly characterized as a UPS substrate, we asked whether Erg25 is a target of the ER associated degradation (ERAD) pathway, which most commonly mediates proteasome-dependent destruction of aberrant proteins. As anticipated, Erg25 was ubiquitinated and associated with stalled proteasomes. Further, Erg25 degradation depended on ERAD-associated ubiquitin ligases and was regulated by sterol synthesis. These data expand the cohort of lipid biosynthetic enzymes targeted for ERAD, highlight the role of the UPS in maintaining ER function, and provide a novel tool to uncover other UPS substrates via manipulations of our engineered strain.




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High-dimensional Cytometry (ExCYT) and Mass Spectrometry of Myeloid Infiltrate in Clinically Localized Clear Cell Renal Cell Carcinoma Identifies Novel Potential Myeloid Targets for Immunotherapy [Research]

Renal Cell Carcinoma (RCC) is one of the most commonly diagnosed cancers worldwide with research efforts dramatically improving understanding of the biology of the disease. To investigate the role of the immune system in treatment-naïve clear cell Renal Cell Carcinoma (ccRCC), we interrogated the immune infiltrate in patient-matched ccRCC tumor samples, benign normal adjacent tissue (NAT) and peripheral blood mononuclear cells (PBMCs isolated from whole blood, focusing our attention on the myeloid cell infiltrate. Using flow cytometric, MS, and ExCYT analysis, we discovered unique myeloid populations in PBMCs across patient samples. Furthermore, normal adjacent tissues and ccRCC tissues contained numerous myeloid populations with a unique signature for both tissues. Enrichment of the immune cell (CD45+) fraction and subsequent gene expression analysis revealed a number of myeloid-related genes that were differentially expressed. These data provide evidence, for the first time, of an immunosuppressive and pro-tumorigenic role of myeloid cells in early, clinically localized ccRCC. The identification of a number of immune proteins for therapeutic targeting provides a rationale for investigation into the potential efficacy of earlier intervention with single-agent or combination immunotherapy for ccRCC.




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ReactomeGSA - Efficient Multi-Omics Comparative Pathway Analysis [Technological Innovation and Resources]

Pathway analyses are key methods to analyze 'omics experiments. Nevertheless, integrating data from different 'omics technologies and different species still requires considerable bioinformatics knowledge.

Here we present the novel ReactomeGSA resource for comparative pathway analyses of multi-omics datasets. ReactomeGSA can be used through Reactome's existing web interface and the novel ReactomeGSA R Bioconductor package with explicit support for scRNA-seq data. Data from different species is automatically mapped to a common pathway space. Public data from ExpressionAtlas and Single Cell ExpressionAtlas can be directly integrated in the analysis. ReactomeGSA greatly reduces the technical barrier for multi-omics, cross-species, comparative pathway analyses.

We used ReactomeGSA to characterize the role of B cells in anti-tumor immunity. We compared B cell rich and poor human cancer samples from five of the Cancer Genome Atlas (TCGA) transcriptomics and two of the Clinical Proteomic Tumor Analysis Consortium (CPTAC) proteomics studies. B cell-rich lung adenocarcinoma samples lacked the otherwise present activation through NFkappaB. This may be linked to the presence of a specific subset of tumor associated IgG+ plasma cells that lack NFkappaB activation in scRNA-seq data from human melanoma. This showcases how ReactomeGSA can derive novel biomedical insights by integrating large multi-omics datasets.




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Novel Proteomic Profiling of Epididymal Extracellular Vesicles in the Domestic Cat Reveals Proteins Related to Sequential Sperm Maturation with Differences Observed between Normospermic and Teratospermic Individuals [Research]

Extracellular vesicles (EVs) secreted by the epididymal epithelium transfer to spermatozoa key proteins that are essential in promoting motility and subsequent fertilization success. Using the domestic cat model, the objectives were to (1) characterize and compare protein content of EVs between segments of the epididymis, and (2) compare EV protein compositions between normo- and teratospermic individuals (producing >60% of abnormal spermatozoa). Epididymal EVs from adult cats were isolated and assessed via liquid chromatography tandem MS. Both male types shared 3008 proteins in total, with 98 and 20 EV proteins unique to normospermic and teratospermic males, respectively. Expression levels of several proteins changed between epididymal segments in both male types. Several proteins in both groups were related to sperm motility (e.g. hexokinase 1, adenylate kinase isoenzyme) and zona pellucida or oolemma binding (e.g. disintegrin and metalloproteinase domain proteins, zona binding proteins 1 and 2). Interestingly, seven cauda-derived EV proteins trended downward in teratospermic compared with normospermic males, which may relate to poor sperm quality. Collective results revealed, for the first time, EV proteins related to sequential sperm maturation with differences observed between normospermic and teratospermic individuals.




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Proteome-wide Analysis Reveals Substrates of E3 Ligase RNF146 Targeted for Degradation [Research]

Specific E3 ligases target tumor suppressors for degradation. Inhibition of such E3 ligases may be an important approach to cancer treatment. RNF146 is a RING domain and PARylation-dependent E3 ligase that functions as an activator of the β-catenin/Wnt and YAP/Hippo pathways by targeting the degradation of several tumor suppressors. Tankyrases 1 and 2 (TNKS1/2) are the only known poly-ADP-ribosyltransferases that require RNF146 to degrade their substrates. However, systematic identification of RNF146 substrates have not yet been performed. To uncover substrates of RNF146 that are targeted for degradation, we generated RNF146 knockout cells and TNKS1/2-double knockout cells and performed proteome profiling with label-free quantification as well as transcriptome analysis. We identified 160 potential substrates of RNF146, which included many known substrates of RNF146 and TNKS1/2 and 122 potential TNKS-independent substrates of RNF146. In addition, we validated OTU domain-containing protein 5 and Protein mono-ADP-ribosyltransferase PARP10 as TNKS1/2-independent substrates of RNF146 and SARDH as a novel substrate of TNKS1/2 and RNF146. Our study is the first proteome-wide analysis of potential RNF146 substrates. Together, these findings not only demonstrate that proteome profiling can be a useful general approach for the systemic identification of substrates of E3 ligases but also reveal new substrates of RNF146, which provides a resource for further functional studies.




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A Mouse Brain-based Multi-omics Integrative Approach Reveals Potential Blood Biomarkers for Ischemic Stroke [Research]

Stroke remains a leading cause of death and disability worldwide. Despite continuous advances, the identification of key molecular signatures in the hyper-acute phase of ischemic stroke is still a primary interest for translational research on stroke diagnosis, prognosis, and treatment. Data integration from high-throughput -omics techniques has become crucial to unraveling key interactions among different molecular elements in complex biological contexts, such as ischemic stroke. Thus, we used advanced data integration methods for a multi-level joint analysis of transcriptomics and proteomics data sets obtained from mouse brains at 2 h after cerebral ischemia. By modeling net-like correlation structures, we identified an integrated network of genes and proteins that are differentially expressed at a very early stage after stroke. We validated 10 of these deregulated elements in acute stroke, and changes in their expression pattern over time after cerebral ischemia were described. Of these, CLDN20, GADD45G, RGS2, BAG5, and CTNND2 were next evaluated as blood biomarkers of cerebral ischemia in mice and human blood samples, which were obtained from stroke patients and patients presenting stroke-mimicking conditions. Our findings indicate that CTNND2 levels in blood might potentially be useful for distinguishing ischemic strokes from stroke-mimicking conditions in the hyper-acute phase of the disease. Furthermore, circulating GADD45G content within the first 6 h after stroke could also play a key role in predicting poor outcomes in stroke patients. For the first time, we have used an integrative biostatistical approach to elucidate key molecules in the initial stages of stroke pathophysiology and highlight new notable molecules that might be further considered as blood biomarkers of ischemic stroke.




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Multiple hypothesis testing in proteomics: A strategy for experimental work [Invited]

In quantitative proteomics work, the differences in expression of many separate proteins are routinely examined to test for significant differences between treatments. This leads to the multiple hypothesis testing problem: when many separate tests are performed many will be significant by chance and be false positive results. Statistical methods such as the false discovery rate (FDR) method that deal with this problem have been disseminated for more than one decade. However a survey of proteomics journals shows that such tests are not widely implemented in one commonly used technique, quantitative proteomics using two-dimensional electrophoresis (2-DE). We outline a selection of multiple hypothesis testing methods, including some that are well known and some lesser known, and present a simple strategy for their use by the experimental scientist in quantitative proteomics work generally. The strategy focuses on the desirability of simultaneous use of several different methods, the choice and emphasis dependent on research priorities and the results in hand. This approach is demonstrated using case scenarios with experimental and simulated model data.




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Interpretation of data underlying the link between CCD and an invertebrate iridescent virus [Invited]

No abstract




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A Pragmatic Guide to Enrichment Strategies for Mass Spectrometry-based Glycoproteomics [Review]

Glycosylation is a prevalent, yet heterogeneous modification with a broad range of implications in molecular biology. This heterogeneity precludes enrichment strategies that can be universally beneficial for all glycan classes. Thus, choice of enrichment strategy has profound implications on experimental outcomes. Here we review common enrichment strategies used in modern mass spectrometry (MS)-based glycoproteomic experiments, including lectins and other affinity chromatographies, hydrophilic interaction chromatography (HILIC) and its derivatives, porous graphitic carbon (PGC), reversible and irreversible chemical coupling strategies, and chemical biology tools that often leverage bioorthogonal handles. Interest in glycoproteomics continues to surge as MS instrumentation and software improve, so this review aims to help equip researchers with necessary information to choose appropriate enrichment strategies that best complement these efforts.




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Integrated glycoproteomics identifies a role of N-glycosylation and galectin-1 on myogenesis and muscle development [Research]

Many cell surface and secreted proteins are modified by the covalent addition of glycans that play an important role in the development of multicellular organisms. These glycan modifications enable communication between cells and the extracellular matrix via interactions with specific glycan-binding lectins and the regulation of receptor-mediated signaling. Aberrant protein glycosylation has been associated with the development of several muscular diseases suggesting essential glycan- and lectin-mediated functions in myogenesis and muscle development but our molecular understanding of the precise glycans, catalytic enzymes and lectins involved remain only partially understood. Here, we quantified dynamic remodeling of the membrane-associated proteome during a time-course of myogenesis in cell culture. We observed wide-spread changes in the abundance of several important lectins and enzymes facilitating glycan biosynthesis. Glycomics-based quantification of released N-linked glycans confirmed remodeling of the glycome consistent with the regulation of glycosyltransferases and glycosidases responsible for their formation including a previously unknown di-galactose-to-sialic acid switch supporting a functional role of these glycoepitopes in myogenesis. Furthermore, dynamic quantitative glycoproteomic analysis with multiplexed stable isotope labelling and analysis of enriched glycopeptides with multiple fragmentation approaches identified glycoproteins modified by these regulated glycans including several integrins and growth factor receptors. Myogenesis was also associated with the regulation of several lectins most notably the up-regulation of galectin-1 (LGALS1). CRISPR/Cas9-mediated deletion of Lgals1 inhibited differentiation and myotube formation suggesting an early functional role of galectin-1 in the myogenic program. Importantly, similar changes in N-glycosylation and the up-regulation of galectin-1 during postnatal skeletal muscle development were observed in mice. Treatment of new-born mice with recombinant adeno-associated viruses to overexpress galectin-1 in the musculature resulted in enhanced muscle mass. Our data form a valuable resource to further understand the glycobiology of myogenesis and will aid the development of intervention strategies to promote healthy muscle development or regeneration.




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Systematic Proteome and Lysine Succinylome Analysis Reveals the Enhanced Cell Migration by Hyposuccinylation in Esophageal Squamous Cell Cancer [Research]

Esophageal squamous cell cancer (ESCC) is an aggressive malignancy with poor therapeutic outcomes. However, the alterations in proteins and post-translational modifications (PTMs) leading to the pathogenesis of ESCC remains unclear. Here, we provide the comprehensive characterization of the proteome, phosphorylome, lysine acetylome and succinylome for ESCC and matched control cells using quantitative proteomic approach. We identify abnormal protein and post-translational modification (PTM) pathways, including significantly downregulated lysine succinylation sites in cancer cells. Focusing on hyposuccinylation, we reveal that this altered PTM was enriched on enzymes of metabolic pathways inextricably linked with cancer metabolism. Importantly, ESCC malignant behaviors such as cell migration are inhibited once the level of succinylation was restored in vitro or in vivo. This effect was further verified by mutations to disrupt succinylation sites in candidate proteins. Meanwhile, we found that succinylation has a negative regulatory effect on histone methylation to promote cancer migration. Finally, hyposuccinylation is confirmed in primary ESCC specimens. Our findings together demonstrate that lysine succinylation may alter ESCC metabolism and migration, providing new insights into the functional significance of PTM in cancer biology.




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Isolation of acetylated and unmodified protein N-terminal peptides by strong cation exchange chromatographic separation of TrypN-digested peptides [Technological Innovation and Resources]

We developed a simple and rapid method to enrich protein N-terminal peptides, in which the protease TrypN is first employed to generate protein N-terminal peptides without Lys or Arg and internal peptides with two positive charges at their N-termini, and then the N-terminal peptides with or without N-acetylation are separated from the internal peptides by strong cation exchange chromatography according to a retention model based on the charge/orientation of peptides. This approach was applied to 20 μg of human HEK293T cell lysate proteins to profile the N-terminal proteome. On average, 1,550 acetylated and 200 unmodified protein N-terminal peptides were successfully identified in a single LC/MS/MS run with less than 3% contamination with internal peptides, even when we accepted only canonical protein N-termini registered in the Swiss-Prot database. Since this method involves only two steps, protein digestion and chromatographic separation, without the need for tedious chemical reactions, it should be useful for comprehensive profiling of protein N-termini, including proteoforms with neo-N-termini.




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On the robustness of graph-based clustering to random network alterations [Research]

Biological functions emerge from complex and dynamic networks of protein-protein interactions. Because these protein-protein interaction networks, or interactomes, represent pairwise connections within a hierarchically organized system, it is often useful to identify higher-order associations embedded within them, such as multi-member protein complexes. Graph-based clustering techniques are widely used to accomplish this goal, and dozens of field-specific and general clustering algorithms exist. However, interactomes can be prone to errors, especially when inferred from high-throughput biochemical assays. Therefore, robustness to network-level noise is an important criterion for any clustering algorithm that aims to generate robust, reproducible clusters. Here, we tested the robustness of a range of graph-based clustering algorithms in the presence of noise, including algorithms common across domains and those specific to protein networks. Strikingly, we found that all of the clustering algorithms tested here markedly amplified noise within the underlying protein interaction network. Randomly rewiring only 1% of network edges yielded more than a 50% change in clustering results, indicating that clustering markedly amplified network-level noise. Moreover, we found the impact of network noise on individual clusters was not uniform: some clusters were consistently robust to injected noise while others were not. To assist in assessing this, we developed the clust.perturb R package and Shiny web application to measure the reproducibility of clusters by randomly perturbing the network. We show that clust.perturb results are predictive of real-world cluster stability: poorly reproducible clusters as identified by clust.perturb are significantly less likely to be reclustered across experiments. We conclude that graph-based clustering amplifies noise in protein interaction networks, but quantifying the robustness of a cluster to network noise can separate stable protein complexes from spurious associations.




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Peptidomics-driven strategy reveals peptides and predicted proteases associated with oral cancer prognosis [Research]

Protease activity has been associated with pathological processes that can lead to cancer development and progression. However, understanding the pathological unbalance in proteolysis is challenging since changes can occur simultaneously at protease, their inhibitor and substrate levels. Here, we present a pipeline that combines peptidomics, proteomics and peptidase predictions for studying proteolytic events in the saliva of seventy-nine patients and their association with oral squamous cell carcinoma (OSCC) prognosis. Our findings revealed differences in the saliva peptidome of patients with (pN+) or without (pN0) lymph node metastasis and delivered a panel of ten endogenous peptides correlated with poor prognostic factors plus five molecules able to classify pN0 and pN+ patients (ROC-AUC>0.85). In addition, endo- and exopeptidases putatively implicated in the processing of differential peptides were investigated using cancer tissue gene expression data from publicly repositories reinforcing their association with poorer survival rates and prognosis in oral cancer. The dynamics of the OSCC-related proteolysis was further explored via the proteomic profiling of saliva. This revealed that peptidase/endopeptidase inhibitors exhibited reduced levels in the saliva of pN+ patients, as confirmed by SRM-MS, whilst minor changes were detected in the level of saliva proteases. Taken together, our results indicated that proteolytic activity is accentuated in the saliva of OSCC patients with lymph node metastasis and, at least in part, this is modulated by reduced levels of salivary peptidase inhibitors. Therefore, this integrated pipeline provided better comprehension and discovery of molecular features with implications in the oral cancer metastasis prognosis.




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Accelerating the field of epigenetic histone modification through mass spectrometry-based approaches [Review]

Histone post-translational modifications (PTMs) are one of the main mechanisms of epigenetic regulation. Dysregulation of histone PTMs leads to many human diseases, such as cancer. Due to its high-throughput, accuracy, and flexibility, mass spectrometry (MS) has emerged as a powerful tool in the epigenetic histone modification field, allowing the comprehensive and unbiased analysis of histone PTMs and chromatin-associated factors. Coupled with various techniques from molecular biology, biochemistry, chemical biology and biophysics, MS has been employed to characterize distinct aspects of histone PTMs in the epigenetic regulation of chromatin functions. In this review we will describe advancements in the field of MS that have facilitated the analysis of histone PTMs and chromatin biology.  




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Imaging Mass Spectrometry and Lectin Analysis of N-linked Glycans in Carbohydrate Antigen Defined Pancreatic Cancer Tissues [Research]

The early detection of pancreatic ductal adenocarcinoma is a complex clinical obstacle yet is key to improving the overall likelihood of patient survival. Current and prospective carbohydrate biomarkers CA19-9 and sTRA are sufficient for surveilling disease progression yet are not approved for delineating PDAC from other abdominal cancers and non-cancerous pancreatic pathologies. To further understand these glycan epitopes, an imaging mass spectrometry approach was utilized to assess the N-glycome of the human pancreas and pancreatic cancer in a cohort of PDAC patients represented by tissue microarrays and whole tissue sections. Orthogonally, these same tissues were characterized by multi-round immunofluorescence which defined expression of CA19-9 and sTRA as well as other lectins towards carbohydrate epitopes with the potential to improve PDAC diagnosis. These analyses revealed distinct differences not only in N-glycan spatial localization across both healthy and diseased tissues but importantly between different biomarker-categorized tissue samples. Unique sulfated bi-antennary N-glycans were detected specifically in normal pancreatic islets. N-glycans from CA19-9 expressing tissues tended to be bi-, tri- and tetra-antennary structures with both core and terminal fucose residues and bisecting N-acetylglucosamines. These N-glycans were detected in less abundance in sTRA-expressing tumor tissues, which favored tri- and tetra-antennary structures with polylactosamine extensions. Increased sialylation of N-glycans was detected in all tumor tissues. A candidate new biomarker derived from IMS was further explored by fluorescence staining with selected lectins on the same tissues. The lectins confirmed the expression of the epitopes in cancer cells and revealed different tumor-associated staining patterns between glycans with bisecting GlcNAc and those with terminal GlcNAc. Thus, the combination of lectin-IHC and IMS techniques produces more complete information for tumor classification than the individual analyses alone. These findings potentiate the development of early assessment technologies to rapidly and specifically identify PDAC in the clinic that may directly impact patient outcomes.




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A potential role for the Gsdf-eEF1{alpha} complex in inhibiting germ cell proliferation: A protein-interaction analysis in medaka (Oryzias latipes) from a proteomics perspective [Research]

Gonadal soma-derived factor (gsdf) has been demonstrated to be essential for testicular differentiation in medaka (Oryzias latipes). To understand the protein dynamics of Gsdf in spermatogenesis regulation, we used a His-tag "pull-down" assay coupled with shotgun LC-MS/MS to identify a group of potential interacting partners for Gsdf, which included cytoplasmic dynein light chain 2, eukaryotic polypeptide elongation factor 1 alpha (eEF1α), and actin filaments in mature medaka testis. As for the interaction with TGFβ-dynein being critical for spermatogonial division in Drosophila melanogaster, the physical interactions of Gsdf-dynein and Gsdf-eEF1α were identified through a yeast 2-hybrid (Y2H) screening of an adult testis cDNA library using Gsdf as bait, which were verified by a paired Y2H assay. Co-immunoprecipitation of Gsdf and eEF1α was defined in adult testes as supporting the requirement of a Gsdf and eEF1α interaction in testis development. Proteomics analysis (data are available via ProteomeXchange with identifier PXD022153) and ultrastrutural observations showed that Gsdf deficiency activated eEF1α-mediated protein synthesis and ribosomal biogenesis, which in turn led to the differentiation of undifferentiated germ cells. Thus, our results provide a framework and new insight into the coordination of a Gsdf (TGFβ and eEF1α complex in the basic processes of germ cell proliferation, transcriptional and translational control of sexual RNA which may be fundamentally conserved across phyla during sexual differentiation.




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Separation and identification of permethylated glycan isomers by reversed phase nanoLC-NSI-MS [Research]

High performance liquid chromatography has been employed for decades to enhance detection sensitivity and quantification of complex analytes within biological mixtures. Among these analytes, glycans released from glycoproteins and glycolipids have been characterized as underivatized or fluorescently tagged derivatives by HPLC coupled to various detection methods. These approaches have proven extremely useful for profiling the structural diversity of glycoprotein and glycolipid glycosylation but require the availability of glycan standards and secondary orthogonal degradation strategies to validate structural assignments. A robust method for HPLC separation of glycans as their permethylated derivatives, coupled with in-line MSn fragmentation to assign structural features independent of standards, would significantly enhance the depth of knowledge obtainable from biological samples. Here, we report an optimized workflow for LC-MS analysis of permethylated glycans that includes sample preparation, mobile phase optimization, and MSn method development to resolve structural isomers on-the-fly. We report baseline separation and MSn fragmentation of isomeric N- and O-glycan structures, aided by supplementing mobile phases with Li+, which simplifies adduct heterogeneity and facilitates cross-ring fragmentation to obtain valuable monosaccharide linkage information. Our workflow has been adapted from standard proteomics-based workflows and, therefore, provides opportunities for laboratories with expertise in proteomics to acquire glycomic data with minimal deviation from existing buffer systems, chromatography media, and instrument configurations. Furthermore, our workflow does not require a mass spectrometer with high-resolution/accurate mass capabilities. The rapidly evolving appreciation of the biological significance of glycans for human health and disease requires the implementation of high-throughput methods to identify and quantify glycans harvested from sample sets of sufficient size to achieve appropriately powered statistical significance. The LC-MSn approach we report generates glycan isomeric separations, robust structural characterization, and is amenable to auto-sampling with associated throughput enhancements.




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The Role of Sub-state and Non-state Actors in International Climate Processes: Corporate Sector

The Role of Sub-state and Non-state Actors in International Climate Processes: Corporate Sector Research paper sysadmin 27 November 2018

Given the challenging political contexts since 2015, the corporate sector will have a key role to play in persuading national governments how technologies and expertise have moved on since the pledges were made.

Photo by Priscilla Du Preez, ‘Climate Reality’ via Unsplash, 2017.

This is one of four background papers feeding into a synthesis paper entitled The Role of Sub-state and Non-state Actors in International Climate Processes.

Summary

  • The corporate sector has traditionally engaged governments at national rather than international level in lobbying for action related to climate change. Where it has engaged at an international level, this has often been to restrain regulation and ambition, such as in air transport. Over time, many businesses have increasingly understood that there is more commercial opportunity in a strong, consistent approach to tackling climate mitigation and adaptation, and an increasing number are willing to speak up on the issue. The Paris Climate Conference in 2015 demonstrated this positive engagement.
  • Businesses are more powerful when engaging directly with national governments on detailed policies – by demonstrating what is possible and indirectly influencing national governments’ international pledges. Traditional trade/industry sector associations and groups have tended to suffer from the ‘lowest common denominator’ effect of their least progressive members. Progressive business groups coalescing around climate ambition can help to counter this.
  • Unlike at the Copenhagen climate talks in 2009, the business community provided a positive, supportive backdrop to the 2015 Paris talks, mindful of the public relations opportunities in taking a progressive stance and of the benefits of targets that reflected the science. The carbon market was a particular focus for corporates, which succeeded in getting emissions trading options and market mechanisms included in Article 6 of the Paris Agreement.
  • Given the challenging political contexts since 2015, the corporate sector will have a key role to play in persuading national governments how technologies and expertise have moved on since the pledges were made. With increasing awareness of resource scarcity, businesses are pursuing ever more creative solutions.
  • Wide recognition that the avoidance of future emissions is increasingly dependent on developing and emerging economies means that business voices from these countries will potentially be more influential in the next few years.




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The Chatham House Sustainable Laboratories Initiative: Prior Assessment Tool

The Chatham House Sustainable Laboratories Initiative: Prior Assessment Tool Other resource sysadmin 14 June 2019

Laboratories are critical for supporting effective infectious disease surveillance and outbreak response. This tool is meant to help structure a conversation between funding partners and recipient countries on how to most effectively establish or repurpose laboratories in low-resource environments.

Copyright: Getty Images/ER Productions Limited

Introduction

Laboratories are critical for supporting effective infectious disease surveillance and outbreak response, and lack of adequate laboratory capacity is a global challenge. As part of global health security initiatives, cooperative threat reduction efforts and international development programmes, sophisticated laboratories have been provided to mitigate biological threats and bolster a country’s capacity for detection, diagnosis and storage of high-consequence pathogens. Very often, these use the assumptions, standards and templates applied in high-income countries. However, it can be difficult or even impossible to sustain these facilities in low-resource environments. There can sometimes be limited local technical capacity and capability, which can result in a high reliance on imported expertise, skills, equipment and other resources. Sustainability can therefore be hard to achieve. In addition, when a funding partner withdraws, the laboratories can become disused, foundering without the trained personnel and financial resources to sustain them.

To help address this situation, a proposal gaining increasing support internationally is to adopt an approach based on a local risk assessment, whereby laboratories are appropriately and optimally tailored to the local risks and to the resources available, both in the short and longer term, without compromising biosafety and biosecurity.

A Chatham House workshop was convened in Abuja, Nigeria, in 2018 to explore what West African countries would find most appropriate in terms of building laboratory capacity, what the main challenges have been so far, and what needs to be done to improve the sustainability of laboratories in the region. It emerged that there was a need for a more structured conversation between the funding partner and recipient country early in the process – prior to embarking on the detailed planning phase for the establishment or repurposing of a laboratory. This should involve careful consideration and an assessment of existing and planned capacity, needs and contextual issues, together with proposals for how to address the issues revealed, so that any ensuing laboratory demonstrably supports the national strategy and therefore flourishes.

The purpose of this tool

This tool aims to provide a structure for such a conversation. Developed in close collaboration with international experts and West African stakeholders, it seeks to increase local ownership and help partners ensure they have given due attention to all the relevant aspects, including risks and benefits, that need to be considered at an early stage. It should provide clarity on what is needed and improve the sustainability of any laboratory project that might result from the discussions. The tool can be applied when a new laboratory is being considered, or when an existing laboratory is to be repurposed or strengthened. It is also appropriate for use with public health, veterinary and environmental laboratories. Although the tool was developed in the context of high-consequence pathogens in Africa, it is anticipated that it will find global application.

It should support recipient countries to take stock of their capacities and capabilities, identify gaps, conduct an analysis of their needs and to develop the business case that can assist in seeking the necessary political and financial support for the laboratory. Meanwhile, it should facilitate the process of due diligence for the funding partner and provide a better understanding of what the recipient country perspective and realities are, and what the scale and nature of any investment might be.




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The Justice Laboratory: International Law in Africa

The Justice Laboratory: International Law in Africa Book dora.popova 30 March 2022

The Justice Laboratory is the first major study of the institutions created to enforce international criminal justice standards in Sub-Saharan Africa, including the UN tribunal for the Rwandan genocide.

Since the Second World War, the United Nations and other international actors have created laws, treaties, and institutions to punish perpetrators of genocide, war crimes, and crimes against humanity. But international criminal justice now seems to be a declining force — its energy sapped by long delays in prosecutions, lagging public attention, and a globally rising authoritarianism that disregards legal niceties.

The Justice Laboratory reviews five examples of international criminal justice as they have been applied across Africa, where brutal civil conflicts in recent decades resulted in varying degrees of global attention and action.

Written in an accessible style, the book explores the connections between politics and the doctrine of international criminal law. Highlighting little-known institutional examples and under-discussed political situations, the book contributes to a broader international understanding of African politics and international criminal justice, and the lessons African experiences can offer to other countries.

This book is part of the Insights series.

 

Praise for The Justice Laboratory

Integrating legal and political analysis, Kerstin Bree Carlson provides a highly accessible and provocative examination of the promises and pitfalls of seeking accountability in a range of contemporary international criminal justice interventions in Africa.

Victor Peskin, School of Politics and Global Studies, Arizona State University

About the author

Kerstin Bree Carlson is associate professor of international law at the Department of Social Science and Business, Roskilde University, where she teaches topics in law and society, global studies, international politics, and Nordic migration.

Purchase




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Optimized incorporation of an unnatural fluorescent amino acid affords measurement of conformational dynamics governing high-fidelity DNA replication [DNA and Chromosomes]

DNA polymerase from bacteriophage T7 undergoes large, substrate-induced conformational changes that are thought to account for high replication fidelity, but prior studies were adversely affected by mutations required to construct a Cys-lite variant needed for site-specific fluorescence labeling. Here we have optimized the direct incorporation of a fluorescent un-natural amino acid, (7-hydroxy-4-coumarin-yl)-ethylglycine, using orthogonal amber suppression machinery in Escherichia coli. MS methods verify that the unnatural amino acid is only incorporated at one position with minimal background. We show that the single fluorophore provides a signal to detect nucleotide-induced conformational changes through equilibrium and stopped-flow kinetic measurements of correct nucleotide binding and incorporation. Pre-steady-state chemical quench methods show that the kinetics and fidelity of DNA replication catalyzed by the labeled enzyme are largely unaffected by the unnatural amino acid. These advances enable rigorous analysis to establish the kinetic and mechanistic basis for high-fidelity DNA replication.




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Whooping cough: Why have vaccination rates plummeted in pregnant women?




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Mpox is accelerating antimicrobial resistance in Africa, officials warn




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How to write an operation note




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South Africa Needs a Strategic Vision for Its Continent

South Africa Needs a Strategic Vision for Its Continent Expert comment sysadmin 24 November 2017

South Africa has the potential to catalyse growth across its sub-region and the continent, but the government must develop a comprehensive strategy that aligns political, ideological and commercial interests.

Departure lounge at OR Tambo International Airport near Johannesburg. Photo: Getty Images.

South Africa’s status as the ‘gateway to Africa’ is under serious threat. Its companies continue to flourish, but complex relationships at home and abroad constrain government capacity to match its economic dominance with political reach and influence.

South Africa’s policies towards the rest of the continent are often accused of being inconsistent and incoherent. It has been a development partner to the region and to international donors; a moral leader, championing human rights and exporting its own model of transition; and an advocate and representative for the continent in international forums. However, it has simultaneously been accused of exploiting its economic dominance at the expense of its neighbours; handicapped by the political debts owed by the ANC to other liberation movements for their assistance in the struggle; and criticized for its arrogance in seeking to position itself as the ‘legitimate’ voice of Africa.

At the same time, reputational risks, a weakened policy environment and poor growth have taken the shine off South Africa’s ‘Gateway to Africa’ rhetoric. South Africa faces considerable domestic economic issues. Growth forecasts have fallen from 1.3 to 0.7 per cent, State owned enterprises are a huge burden on the treasury, and the forecast budget deficit is R50.8 billion (£2.7 billion), at a time when the cost of borrowing is increasing following downgrades of the country’s credit ratings.

Political risk is high, lowering investor confidence. Corruption, poor service delivery and the government’s under-delivery on citizen’s expectations are exacerbating social tensions in a country with expanded unemployment at 36.4 per cent, and one of the highest rates of inequality in the world. McKinsey, KPMG and HSBC have all become entangled in scandal relating to their dealings with government entities that have become ‘captured’ by private interests.

Despite these concerns, South Africa nonetheless remains the backbone of the regional economy, and its firms are key players across the continent. Johannesburg hosts the deepest and most sophisticated capital market on the continent, and Pretoria has one of the highest numbers of diplomatic missions in the world. ESKOM provides around 75 per cent of the electricity contribution to the Southern Africa SADC Power pool – comprising 12 countries, including those as far north as DRC and Tanzania – and South African ports facilitate over half of sub-Saharan Africa’s non-commodity trade with the rest of the world.

Post-apartheid expansion across the continent by South African companies was initially met with resistance, but these relationships have improved significantly – and South African firms retain significant advantages. South African retailers have the scale to incorporate regional producers into continental supply chains, purchasing fresh produce at a competitive price from regional agri-businesses, then re-selling further afield. For example, Zambeef supplies meat from Zambia to Shoprite stores in west Africa.

African companies in turn rely on South Africa as a significant consumer of goods, services and primary commodities. A South African government agreement with the DRC to import about half of the electricity that will be produced by a new grand-scale hydro-power project guaranteed its bankability. Mozambique is looking to maximize the potential of its world-class natural gas reserves by building a pipeline into South Africa, thus benefitting from the purchasing power of South African parastatal electricity utility firm ESKOM.

But South Africa’s status as an economic hegemon is not mirrored in its political relationships. South Africa’s GDP is five times higher than the six countries with which it shares a border, combined. But successive ANC governments have been unable to fully flex this economic muscle. Partly this is a legacy of history. It is not forgotten that the regional economic body, the Southern African Development Community, originated as the organization of Front Line States coordinating efforts to end apartheid, and ZANU-PF officials in Zimbabwe lecture their ANC counterparts on liberation.

The pan-African vision of former president Thabo Mbeki, and promotion of South Africa’s transition as a model for the continent, reflected the values that have driven ANC policy since the end of apartheid. But the coherence of South Africa’s foreign policy has been undermined by conflict and contradiction within the government. Appetite for engagement in Africa is dwindling. The country’s ability to project military influence across the continent is in critical decline. Jacob Zuma’s use of regional political bodies as a means of removing political rivals from domestic politics has corroded goodwill.

A new Africa Programme research paper argues that a fresh approach to South African engagement on the continent is both possible and necessary. South Africa can use its relative economic weight to play a stronger developmental role, leveraging the strengths of its business sector and its financial agencies. But it must match this with stronger and more cooperative political engagement, particularly through cultivating relationships with pivotal states such as Nigeria, Kenya, Ethiopia and Angola.

In December, the ANC will elect a new leader to take the party into elections in 2019. Both leading candidates have international experience – Nkosazana Dlamini-Zuma was the chair of the African Union, and Cyril Ramaphosa has led regional responses to crises in South Sudan, Lesotho and Burundi. South Africa still has considerable foreign policy resources at its disposal. A new strategic vision for Africa that unites the interests of government and business, both domestically and in partner states, can deliver prosperity for both South Africa and the region – and need not contradict the values that have shaped South Africa’s aspirations for the continent in the post-apartheid era.




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Can Liberation Movements Really Rid Southern Africa of Corruption?

Can Liberation Movements Really Rid Southern Africa of Corruption? Expert comment sysadmin 16 December 2019

Southern Africa’s national liberation movements have survived ‘end of decade’ elections across the region. Combating corruption has been at the heart of many of the campaigns, but the question is can they succeed?

Supporters of the Namibian incumbent president and ruling party South West Africa People’s Organisation (SWAPO) presidential candidate Hage Geingob cheer and dance. Photo by GIANLUIGI GUERCIA/AFP via Getty Images.

Swapo’s victory in Namibia two weeks ago was the last in a series of recent ‘end of decade’ elections that have returned dominant parties to power across Southern Africa. However, the “enduring appeal of liberation” is wearing thin.

Experiences across the region show that if governments are to deliver on their electoral promises, they must empower institutions, actively promote a culture of accountability and transparency within their party ranks and pursue economic reforms that untangle the web of party-state-business alliances. Such actions are critical for the survival of national liberation movements as the dominant force in the politics of Southern Africa – but will be difficult to implement.

Avoid political factionalism

South Africa, Botswana, Angola and Zimbabwe all saw new presidents take over just before elections. All used the rhetoric of anti-corruption to distance themselves from the tainted image of their predecessors. But acting on this requires a shift in mind-set in parties that have always preferred to deal with their problems behind closed doors. High profile adversaries from past regimes make tempting targets but could also drive party divisions.

In Angola, the transition of power was safeguarded by an agreement that former president José Eduardo dos Santos would be immune from prosecution. But this week his son faced corruption charges before the country’s supreme court, a high-profile example of a wave of anti-corruption cases across Southern Africa, driven by dominant parties wary of their future.

The allegations against José Filemino De Sousa Dos Santos, nickname ‘Zenu’, include a $500-million fraud involving the country’s central bank. Pressure is also mounting on Zenu’s sister Isabel — once prominent in Angola, she is now absent from public life.

Other leaders have had to tread more carefully. Immunity was a luxury Cyril Ramaphosa was neither willing nor politically able to grant Jacob Zuma in South Africa. Reliant on a few close allies at the top of the party, Ramaphosa lacks foot soldiers at the grassroots level, and his campaign against corruption within the ANC has faced persistent opposition.

Rebuilding institutions and empowering authorities takes time, and with few high-profile cases to point to, people are getting restless. This is also the case in Zimbabwe, where a worsening economic situation has left policy reformers politically isolated.

Party, state, and business

Long term incumbency has blurred the distinction between the party and the state. Liberation movements have created vast party-linked business empires. Political allegiance grants access to economic resources through appointments to lucrative positions in state-owned enterprises, preferential bids for tenders and licenses, and direct access to decision makers.

In Angola, this was fuelled by oil revenues. In South Africa, state capture flourished in an environment where the ANC and its constituent elements had significant power on the panels that chose leaders for state-owned enterprises (SOEs). In Namibia, an Icelandic fishing company paid backhanders to officials for fishing rights in what has become known as the ‘Fishrot’ scandal. Zanu-PF officials’ access to preferential foreign exchange rates present them with lucrative opportunities in Zimbabwe.

Ending this bureaucratic rent seeking goes beyond appointing ‘clean’ officials, which has been central to the anti-corruption campaigns in Angola and South Africa. Governments must also allow scrutiny of the state and empower those institutions designed for that role, such as the National Prosecuting Authority and the Public Protector in South Africa. Zimbabwe’s auditor general has published an in-depth report of the state of corruption in the country’s SOEs.

Companies must also be held to account for their role in aiding, and at worst directly benefitting, from state graft. International businesses have actively sought to benefit from corruption. They are now starting to face the consequences. A former Credit Suisse banker has pleaded guilty in the US over handling alleged kickbacks in Mozambique’s $2-billion “tuna bond” scandal. Global banks and consultancies continue to feel the squeeze for their complicity in state capture in South Africa.

Competition and pluralism

National liberation movements may only have a limited window within which to act. Across the region civil society campaigns and investigative journalists have shed light on some of the worst abuses of power. Anti-corruption campaigns are starting to bite. The state will continue to play a central role in Southern African economies, an important arbiter of economic transformation able to balance the region’s highly unequal and resource-dependent economies.

But opposition, civil society and the media are also critical for the progression towards democratic competition and pluralism in Southern Africa. Parliaments remain vital for holding rulers to account. Long used to unchallenged dominance, liberation movements have significant adjustments to make to rise to the challenge of a new era.

This article was originally published in the Mail and Guardian.




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Zimbabwe’s Economic Governance and Regional Integration

Zimbabwe’s Economic Governance and Regional Integration 17 November 2020 — 12:00PM TO 1:30PM Anonymous (not verified) 6 November 2020 Online

Panellists discuss policy and governance for long-term economic prosperity in Zimbabwe, reflecting on the role of institutional change and regional integration in the context of the shocks caused by the coronavirus pandemic.

At this virtual event, panellists and participants will discuss policy and governance for long-term economic prosperity in Zimbabwe, reflecting on the role of institutional change and regional integration.

The government of Zimbabwe has emphasized its commitment to economic reform and its ambition to achieve upper-middle-income status by 2030, but there are considerable challenges to overcome.

The COVID-19 pandemic has exacerbated existing economic fragility. Improving the business climate to attract international private-sector investment will be contingent on clear, consistent and coherent policy and implementation, including targeting abuse and corruption.

Zimbabwe has, in recent years, successfully strengthened its regional trade integration, although some trade frictions remain. This is an important factor not only for catalysing economic growth in Zimbabwe, but for supporting regional prosperity and post-COVID recovery.

This webinar is the second in a series of events held in partnership with the Konrad Adenauer Stiftung on Zimbabwe’s economic reform and recovery.

Read a meeting summary

This event will also be broadcast live on the Africa Programme Facebook page.




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Moderate alcohol intake is linked to lower risk of ischaemic stroke, study finds




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Covid-19: Progression to clinical type 1 diabetes accelerated after infection, study suggests




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Nigeria's 2023 elections: Security, economic and foreign policy imperatives

Nigeria's 2023 elections: Security, economic and foreign policy imperatives 5 December 2022 — 1:00PM TO 2:00PM Anonymous (not verified) 23 November 2022 Chatham House and Online

Bola Ahmed Tinubu, presidential candidate for the All-Progressives Congress, discusses his vision and recently-unveiled manifesto for ‘renewing hope’ in Nigeria.

Nigeria is scheduled to hold presidential and national assembly elections on 25 February 2023 as well as governorship and other subnational elections on 11 March 2023.

The elections will end President Muhammadu Buhari’s two terms in office since his election in 2015 and will mark the first time that he is not engaging in a presidential poll since Nigeria’s transition to civilian rule in 1999 – an important marker in Nigeria’s trajectory of democratic consolidation.

Nigeria’s recently enacted Electoral Act has contributed to improved hope around the election process, reflected in the addition of 12.29 million new voters in Nigeria’s voter registration exercise across the federation’s 36 states and 1,491 constituencies.

Yet Nigeria stands at a critical juncture, having suffered from two recessions in the past six years, unprecedented levels of food insecurity, persistent fuel scarcity and high levels of crude oil theft.

Civic fatigue also remains an important challenge and President Muhammadu Buhari’s three main policy pillars of security, economy and corruption continue to be defining issues for citizens.

At this event, Bola Ahmed Tinubu, presidential candidate for the All-Progressives Congress, discusses his vision and recently unveiled manifesto for ‘renewing hope’ in Nigeria including his policy proposals for economic reform and revival and how to deliver secure and inclusive job opportunities for Nigerian citizens.

Download a transcript

This event is a members and Africa programme event and is part of a series of events and outputs examining Nigeria’s 2023 elections and political developments.

As with all Chatham House member events, questions from members drive the conversation.




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Europe's strategic choices 2021

Europe's strategic choices 2021 4 November 2021 TO 5 November 2021 — 8:00AM TO 5:30PM Anonymous (not verified) 21 September 2021 Ritz Carlton Berlin

The 2021 conference will consider how Europe can navigate its political, economic and security challenges, in the context of the lasting effects of the coronavirus pandemic and an increasingly competitive geopolitical environment.

Registration is a two step process and you will receive a link to register on the conference virtually in advance. Please email if you wish to attend in-person.

The Eighth Annual Europe’s Strategic Choices conference, jointly developed and hosted by Chatham House, the Institute for Security Policy at the University of Kiel and the Konrad-Adenauer-Stiftung, aims to understand the complex set of challenges facing Europe in the areas of security, economic competitiveness, trade, technology, and global influence.

Set against the backdrop of a Europe emerging gradually from the COVID-19 pandemic, this annual forum brings together policymakers, and representatives from business, civil society and academia, to explore how European countries can best respond, individually and collectively to their common challenges in an increasingly competitive geopolitical environment.

The conference will be hosted in hybrid format to enable speakers and participants to join in person and allow others to engage virtually via the Conference Plus digital platform. This format ensures we can connect with a geographically diverse audience whilst incorporating important elements of in person engagement in accordance with German Federal government guidelines.