11 August 2020

12 August 2020

Cellular energy demands are met by uptake and metabolism of nutrients like glucose. The principal transcriptional regulator for adapting glycolytic flux and downstream pathways like de novo lipogenesis to glucose availability in many cell types is carbohydrate response element–binding protein (ChREBP). ChREBP is activated by glucose metabolites and post-translational modifications, inducing nuclear accumulation and regulation of target genes. Here we report that ChREBP is modified by proline hydroxylation at several residues. Proline hydroxylation targets both ectopically expressed ChREBP in cells and endogenous ChREBP in mouse liver. Functionally, we found that specific hydroxylated prolines were dispensable for protein stability but required for the adequate activation of ChREBP upon exposure to high glucose. Accordingly, ChREBP target gene expression was rescued by re-expressing WT but not ChREBP that lacks hydroxylated prolines in ChREBP-deleted hepatocytes. Thus, proline hydroxylation of ChREBP is a novel post-translational modification that may allow for therapeutic interference in metabolic diseases.

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Wenhe Zhu
Dec 29, 2020; 0:RA120.002353v1-mcp.RA120.002353
Research

Xiao-Ting Wen
Dec 17, 2020; 0:RA120.002119v1-mcp.RA120.002119
Research

Alison M. Kurimchak
Dec 1, 2020; 19:2068-2089
Research

Diana Samodova
Dec 1, 2020; 19:2139-2156
Technological Innovation and Resources

The kinesin-3 family contains the fastest and most processive motors of the three neuronal transport kinesin families, yet the sequence of states and rates of kinetic transitions that comprise the chemomechanical cycle and give rise to their unique properties are poorly understood. We used stopped-flow fluorescence spectroscopy and single-molecule motility assays to delineate the chemomechanical cycle of the kinesin-3, KIF1A. Our bacterially expressed KIF1A construct, dimerized via a kinesin-1 coiled-coil, exhibits fast velocity and superprocessivity behavior similar to WT KIF1A. We established that the KIF1A forward step is triggered by hydrolysis of ATP and not by ATP binding, meaning that KIF1A follows the same chemomechanical cycle as established for kinesin-1 and -2. The ATP-triggered half-site release rate of KIF1A was similar to the stepping rate, indicating that during stepping, rear-head detachment is an order of magnitude faster than in kinesin-1 and kinesin-2. Thus, KIF1A spends the majority of its hydrolysis cycle in a one-head-bound state. Both the ADP off-rate and the ATP on-rate at physiological ATP concentration were fast, eliminating these steps as possible rate-limiting transitions. Based on the measured run length and the relatively slow off-rate in ADP, we conclude that attachment of the tethered head is the rate-limiting transition in the KIF1A stepping cycle. Thus, KIF1A's activity can be explained by a fast rear-head detachment rate, a rate-limiting step of tethered-head attachment that follows ATP hydrolysis, and a relatively strong electrostatic interaction with the microtubule in the weakly bound post-hydrolysis state.

Alice Santonastaso
Dec 1, 2020; 61:1687-1696
Research Articles

In SAS Business Rules Manager 3.3, the initial loading of a rule set and a rule flow takes significantly longer than it does in release 3.2. When this problem happens, long time gaps are evident in the local

When you publish a model to SAS Metadata Repository by using SAS Model Manager, the publishing process fails and the following error is generated: "The model model-name has a function of ';Transformation';, which is not supported for

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.

Sphingolipids have become established participants in the pathogenesis of obesity and its associated maladies. Sphingosine kinase 1 (SPHK1), which generates S1P, has been shown to increase in liver and adipose of obese humans and mice and to regulate inflammation in hepatocytes and adipose tissue, insulin resistance, and systemic inflammation in mouse models of obesity. Previous studies by us and others have demonstrated that global sphingosine kinase 1 KO mice are protected from diet-induced obesity, insulin resistance, systemic inflammation, and NAFLD, suggesting that SPHK1 may mediate pathological outcomes of obesity. As adipose tissue dysfunction has gained recognition as a central instigator of obesity-induced metabolic disease, we hypothesized that SPHK1 intrinsic to adipocytes may contribute to HFD-induced metabolic pathology. To test this, we depleted Sphk1 from adipocytes in mice (SK1^fatKO) and placed them on a HFD. In contrast to our initial hypothesis, SK1^fatKO mice displayed greater weight gain on HFD and exacerbated impairment in glucose clearance. Pro-inflammatory cytokines and neutrophil content of adipose tissue were similar, as were levels of circulating leptin and adiponectin. However, SPHK1-null adipocytes were hypertrophied and had lower basal lipolytic activity. Interestingly, hepatocyte triacylglycerol accumulation and expression of pro-inflammatory cytokines and collagen 1a1 were exacerbated in SK1^fatKO mice on a HFD, implicating a specific role for adipocyte SPHK1 in adipocyte function and inter-organ cross-talk that maintains overall metabolic homeostasis in obesity. Thus, SPHK1 serves a previously unidentified essential homeostatic role in adipocytes that protects from obesity-associated pathology. These findings may have implications for pharmacological targeting of the SPHK1/S1P signaling axis.

Atherosclerosis is characterized by the pathological accumulation of cholesterol-laden macrophages in the arterial wall. Atherosclerosis is also the main underlying cause of CVDs, and its development is largely driven by elevated plasma cholesterol. Strong epidemiological data find an inverse association between plasma β-carotene with atherosclerosis, and we recently showed that β-carotene oxygenase 1 (BCO1) activity, responsible for β-carotene cleavage to vitamin A, is associated with reduced plasma cholesterol in humans and mice. In this study, we explore whether intact β-carotene or vitamin A affects atherosclerosis progression in the atheroprone LDLR-deficient mice. Compared with control-fed Ldlr^–/– mice, β-carotene-supplemented mice showed reduced atherosclerotic lesion size at the level of the aortic root and reduced plasma cholesterol levels. These changes were absent in Ldlr^–/–/Bco1^–/– mice despite accumulating β-carotene in plasma and atherosclerotic lesions. We discarded the implication of myeloid BCO1 in the development of atherosclerosis by performing bone marrow transplant experiments. Lipid production assays found that retinoic acid, the active form of vitamin A, reduced the secretion of newly synthetized triglyceride and cholesteryl ester in cell culture and mice. Overall, our findings provide insights into the role of BCO1 activity and vitamin A in atherosclerosis progression through the regulation of hepatic lipid metabolism.

Fabry disease is caused by deficient activity of α-galactosidase A, an enzyme that hydrolyzes the terminal α-galactosyl moieties from glycolipids and glycoproteins, and subsequent accumulation of glycosphingolipids, mainly globotriaosylceramide (Gb₃), globotriaosylsphingosine (lyso-Gb₃), and galabiosylceramide. However, there is no known link between these compounds and disease severity. In this study, we compared Gb₃ isoforms (various fatty acids) and lyso-Gb₃ analogs (various sphingosine modifications) in two strains of Fabry disease mouse models: a pure C57BL/6 (B6) background or a B6/129 mixed background, with the latter exhibiting more prominent cardiac and renal hypertrophy and thermosensation deficits. Total Gb₃ and lyso-Gb₃ levels in the heart, kidney, and dorsal root ganglion (DRG) were similar in the two strains. However, levels of the C20-fatty acid isoform of Gb₃ and particular lyso-Gb₃ analogs (+18, +34) were significantly higher in Fabry-B6/129 heart tissue when compared with Fabry-B6. By contrast, there was no difference in Gb₃ and lyso-Gb₃ isoforms/analogs in the kidneys and DRG between the two strains. Furthermore, using immunohistochemistry, we found that Gb₃ massively accumulated in DRG mechanoreceptors, a sensory neuron subpopulation with preserved function in Fabry disease. However, Gb₃ accumulation was not observed in nonpeptidergic nociceptors, the disease-relevant subpopulation that has remarkably increased isolectin-B4 (the marker of nonpeptidergic nociceptors) binding and enlarged cell size. These findings suggest that specific species of Gb₃ or lyso-Gb₃ may play major roles in the pathogenesis of Fabry disease, and that Gb₃ and lyso-Gb₃ are not responsible for the pathology in all tissues or cell types.

Lipoprotein (a) [Lp(a)] is characterized by an LDL-like composition in terms of lipids and apoB100, and by one copy of a unique glycoprotein, apo(a). The apo(a) structure is mainly based on the repetition of tandem kringle domains with high homology to plasminogen kringles 4 and 5. Among them, kringle IV type 2 (KIV-2) is present in a highly variable number of genetically encoded repeats, whose length is inversely related to Lp(a) plasma concentration and cardiovascular risk. Despite it being the major component of apo(a), the actual function of KIV-2 is still unclear. Here, we describe the first high-resolution crystallographic structure of this domain. It shows a general fold very similar to other KIV domains with high and intermediate affinity for the lysine analog, -aminocaproic acid. Interestingly, KIV-2 presents a lysine binding site (LBS) with a unique shape and charge distribution. KIV-2 affinity for predicted small molecule binders was found to be negligible in surface plasmon resonance experiments; and with the LBS being nonfunctional, we propose to rename it "pseudo-LBS". Further investigation of the protein by computational small-molecule docking allowed us to identify a possible heparin-binding site away from the LBS, which was confirmed by specific reverse charge mutations abolishing heparin binding. This study opens new possibilities to define the pathogenesis of Lp(a)-related diseases and to facilitate the design of specific therapeutic drugs.

Despite the continued analysis of HDAC inhibitors in clinical trials, the heterogeneous nature of the protein complexes they target limits our understanding of the beneficial and off-target effects associated with their application. Among the many HDAC protein complexes found within the cell, Sin3 complexes are conserved from yeast to humans and likely play important roles as regulators of transcriptional activity. The presence of two Sin3 paralogs in humans, SIN3A and SIN3B, may result in a heterogeneous population of Sin3 complexes and contributes to our poor understanding of the functional attributes of these complexes. Here, we profile the interaction networks of SIN3A and SIN3B to gain insight into complex composition and organization. In accordance with existing data, we show that Sin3 paralog identity influences complex composition. Additionally, chemical cross-linking MS identifies domains that mediate interactions between Sin3 proteins and binding partners. The characterization of rare SIN3B proteoforms provides additional evidence for the existence of conserved and divergent elements within human Sin3 proteins. Together, these findings shed light on both the shared and divergent properties of human Sin3 proteins and highlight the heterogeneous nature of the complexes they organize.

The neuronal basis of complex social behavior is still poorly understood. In honeybees, reproductive investment decisions are made at the colony-level. Queens develop from female-destined larvae that receive alloparental care from nurse bees in the form of ad-libitum royal jelly (RJ) secretions. Typically, the number of raised new queens is limited but genetic breeding of "royal jelly bees" (RJBs) for enhanced RJ production over decades has led to a dramatic increase of reproductive investment in queens. Here, we compare RJBs to unselected Italian bees (ITBs) to investigate how their cognitive processing of larval signals in the mushroom bodies (MBs) and antennal lobes (ALs) may contribute to their behavioral differences. A cross-fostering experiment confirms that the RJB syndrome is mainly due to a shift in nurse bee alloparental care behavior. Using olfactory conditioning of the proboscis extension reflex, we show that the RJB nurses spontaneously respond more often to larval odors compared with ITB nurses but their subsequent learning occurs at similar rates. These phenotypic findings are corroborated by our demonstration that the proteome of the brain, particularly of the ALs differs between RJBs and ITBs. Notably, in the ALs of RJB newly emerged bees and nurses compared with ITBs, processes of energy and nutrient metabolism, signal transduction are up-regulated, priming the ALs for receiving and processing the brood signals from the antennae. Moreover, highly abundant major royal jelly proteins and hexamerins in RJBs compared with ITBs during early life when the nervous system still develops suggest crucial new neurobiological roles for these well-characterized proteins. Altogether, our findings reveal that RJBs have evolved a strong olfactory response to larvae, enabled by numerous neurophysiological adaptations that increase the nurse bees' alloparental care behavior.

MS-based proteome profiling has become increasingly comprehensive and quantitative, yet a persistent shortcoming has been the relatively large samples required to achieve an in-depth measurement. Such bulk samples, typically comprising thousands of cells or more, provide a population average and obscure important cellular heterogeneity. Single-cell proteomics capabilities have the potential to transform biomedical research and enable understanding of biological systems with a new level of granularity. Recent advances in sample processing, separations and MS instrumentation now make it possible to quantify >1000 proteins from individual mammalian cells, a level of coverage that required an input of thousands of cells just a few years ago. This review discusses important factors and parameters that should be optimized across the workflow for single-cell and other low-input measurements. It also highlights recent developments that have advanced the field and opportunities for further development.

Trypsin is the protease of choice in bottom-up proteomics. However, its application can be limited by the amino acid composition of target proteins and the pH of the digestion solution. In this study we characterize ProAlanase, a protease from the fungus Aspergillus niger that cleaves primarily on the C-terminal side of proline and alanine residues. ProAlanase achieves high proteolytic activity and specificity when digestion is carried out at acidic pH (1.5) for relatively short (2 h) time periods. To elucidate the potential of ProAlanase in proteomics applications, we conducted a series of investigations comprising comparative multi-enzymatic profiling of a human cell line proteome, histone PTM analysis, ancient bone protein identification, phosphosite mapping and de novo sequencing of a proline-rich protein and disulfide bond mapping in mAb. The results demonstrate that ProAlanase is highly suitable for proteomics analysis of the arginine- and lysine-rich histones, enabling high sequence coverage of multiple histone family members. It also facilitates an efficient digestion of bone collagen thanks to the cleavage at the C terminus of hydroxyproline which is highly prevalent in collagen. This allows to identify complementary proteins in ProAlanase- and trypsin-digested ancient bone samples, as well as to increase sequence coverage of noncollagenous proteins. Moreover, digestion with ProAlanase improves protein sequence coverage and phosphosite localization for the proline-rich protein Notch3 intracellular domain (N3ICD). Furthermore, we achieve a nearly complete coverage of N3ICD protein by de novo sequencing using the combination of ProAlanase and tryptic peptides. Finally, we demonstrate that ProAlanase is efficient in disulfide bond mapping, showing high coverage of disulfide-containing regions in a nonreduced mAb.

Endometrial carcinoma (EC) is the most common gynecologic malignancy in the United States, with limited effective targeted therapies. Endometrial tumors exhibit frequent alterations in protein kinases, yet only a small fraction of the kinome has been therapeutically explored. To identify kinase therapeutic avenues for EC, we profiled the kinome of endometrial tumors and normal endometrial tissues using Multiplexed Inhibitor Beads and Mass Spectrometry (MIB-MS). Our proteomics analysis identified a network of kinases overexpressed in tumors, including Serine/Arginine-Rich Splicing Factor Kinase 1 (SRPK1). Immunohistochemical (IHC) analysis of endometrial tumors confirmed MIB-MS findings and showed SRPK1 protein levels were highly expressed in endometrioid and uterine serous cancer (USC) histological subtypes. Moreover, querying large-scale genomics studies of EC tumors revealed high expression of SRPK1 correlated with poor survival. Loss-of-function studies targeting SRPK1 in an established USC cell line demonstrated SRPK1 was integral for RNA splicing, as well as cell cycle progression and survival under nutrient deficient conditions. Profiling of USC cells identified a compensatory response to SRPK1 inhibition that involved EGFR and the up-regulation of IGF1R and downstream AKT signaling. Co-targeting SRPK1 and EGFR or IGF1R synergistically enhanced growth inhibition in serous and endometrioid cell lines, representing a promising combination therapy for EC.

Ankylosing Spondylitis (AS) is a common, inflammatory rheumatic disease, which primarily affects the axial skeleton and is associated with sacroiliitis, uveitis and enthesitis. Unlike other autoimmune rheumatic diseases, such as rheumatoid arthritis or systemic lupus erythematosus, autoantibodies have not yet been reported to be a feature of AS. We therefore wished to determine if plasma from patients with AS contained autoantibodies and if so, characterize and quantify this response in comparison to patients with Rheumatoid Arthritis (RA) and healthy controls. Two high-density nucleic acid programmable protein arrays expressing a total of 3498 proteins were screened with plasma from 25 patients with AS, 17 with RA and 25 healthy controls. Autoantigens identified were subjected to Ingenuity Pathway Analysis in order to determine patterns of signalling cascades or tissue origin. 44% of patients with Ankylosing Spondylitis demonstrated a broad autoantibody response, as compared to 33% of patients with RA and only 8% of healthy controls. Individuals with AS demonstrated autoantibody responses to shared autoantigens, and 60% of autoantigens identified in the AS cohort were restricted to that group. The AS patients autoantibody responses were targeted towards connective, skeletal and muscular tissue, unlike those of RA patients or healthy controls. Thus, patients with AS show evidence of systemic humoral autoimmunity and multispecific autoantibody production. Nucleic Acid Programmable Protein Arrays constitute a powerful tool to study autoimmune diseases.

Protein tyrosine kinases (PTKs) play key roles in cellular signal transduction, cell cycle regulation, cell division, and cell differentiation. Dysregulation of PTK-activated pathways, often by receptor overexpression, gene amplification, or genetic mutation, is a causal factor underlying numerous cancers. In this study, we have developed a parallel reaction monitoring (PRM)-based assay for quantitative profiling of 83 PTKs. The assay detects 308 proteotypic peptides from 54 receptor tyrosine kinases and 29 nonreceptor tyrosine kinases in a single run. Quantitative comparisons were based on the labeled reference peptide method. We implemented the assay in four cell models: 1) a comparison of proliferating versus epidermal growth factor (EGF)-stimulated A431 cells, 2) a comparison of SW480Null (mutant APC) and SW480APC (APC restored) colon tumor cell lines, and 3) a comparison of 10 colorectal cancer cell lines with different genomic abnormalities, and 4) lung cancer cell lines with either susceptibility (11-18) or acquired resistance (11-18R) to the epidermal growth factor receptor tyrosine kinase inhibitor erlotinib. We observed distinct PTK expression changes that were induced by stimuli, genomic features or drug resistance, which were consistent with previous reports. However, most of the measured expression differences were novel observations. For example, acquired resistance to erlotinib in the 11-18 cell model was associated not only with previously reported upregulation of MET, but also with upregulation of FLK2 and downregulation of LYN and PTK7. Immunoblot analyses and shotgun proteomics data were highly consistent with PRM data. Multiplexed PRM assays provide a targeted, systems-level profiling approach to evaluate cancer-related proteotypes and adaptations. Data are available through Proteome eXchange Accession PXD002706.

This article has been withdrawn by the authors. This article did not comply with the editorial guidelines of MCP. Specifically, single peptide based protein identifications of 9-19% were included in the analysis and discussed in the results and conclusions. We wish to withdraw this article and resubmit a clarified, corrected manuscript for review.

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.

Antibodies play essential roles in both diagnostics and therapeutics. Epitope mapping is essential to understand how an antibody works and to protect intellectual property. Given the millions of antibodies for which epitope information is lacking, there is a need for high-throughput epitope mapping. To address this, we developed a strategy, Antibody binding epitope Mapping (AbMap), by combining a phage displayed peptide library with next generation sequencing. Using AbMap, profiles of the peptides bound by 202 antibodies were determined in a single test, and linear epitopes were identified for >50% of the antibodies. Using spike protein (S1 and S2)-enriched antibodies from the convalescent serum of one COVID-19 patient as the input, both linear and conformational epitopes of spike protein specific antibodies were identified. We defined peptide-binding profile of an antibody as the Binding Capacity (BiC). Conceptually, the BiC could serve as a systematic and functional descriptor of any antibody. Requiring at least one order of magnitude less time and money to map linear epitopes than traditional technologies, AbMap allows for high-throughput epitope mapping and creates many possibilities.

Thermal proteome profiling (TPP) allows for the unbiased detection of drug – target protein engagements in vivo. Traditionally, one cell type is used for TPP studies, with the risk of missing important differentially expressed target proteins. The use of whole organisms would circumvent this problem. Zebrafish embryos are amenable to such an approach. Here, we used TPP on whole zebrafish embryo lysate to identify protein targets of napabucasin, a compound that may affect Signal transducer and activator of transcription 3 (Stat3) signaling through an ill-understood mechanism. In zebrafish embryos, napabucasin induced developmental defects consistent with inhibition of Stat3 signaling. TPP profiling showed no distinct shift in Stat3 upon napabucasin treatment, but effects were detected on the oxidoreductase, Pora, which might explain effects on Stat3 signaling. Interestingly, thermal stability of several aldehyde dehydrogenases (Aldhs) was affected. Moreover, napabucasin activated ALDH enzymatic activity in vitro. Aldhs have crucial roles in retinoic acid metabolism and functionally we validated napabucasin-mediated activation of the retinoic acid pathway in zebrafish in vivo. We conclude that TPP profiling in whole zebrafish embryo lysate is feasible and facilitates direct correlation of in vivo effects of small molecule drugs with their protein targets.

The increasing consumption of high-fat foods combined with a lack of exercise is a major contributor to the burden of obesity in humans. Aerobic exercise such as running is known to provide metabolic benefits, but how the over-consumption of a high fat diet (HFD) and exercise interact is not well characterized at the molecular level. Here, we examined the plasma proteome in mice for the effects of aerobic exercise as both a treatment and as a preventative regime for animals on either HFD or a healthy control diet. This analysis detected large changes in the plasma proteome induced by the HFD, such as increased abundance of SERPINA7, ALDOB, and down-regulation of SERPINA1E, CFD (adipsin). Some of these changes were significantly reverted using exercise as a preventative measure, but not as a treatment regime. To determine if either the intensity, or duration, of exercise influenced the outcome, we compared high-intensity interval training (HIIT) and endurance running. Endurance running slightly out-performed HIIT exercise, but overall, both provided similar reversion in abundance of plasma proteins modulated by the high-fat diet including SERPINA7, APOE, SERPINA1E, and CFD. Finally, we compared the changes induced by over-consumption of HFD to previous data from mice fed an isocaloric high saturated fat (SFA) or polyunsaturated fat (PUFA) diet. This identified several common changes including increased APOC2 and APOE, but also highlighted changes specific for either over-consumption of HFD (ALDOB, SERPINA7, CFD), SFA-based diets (SERPINA1E), or PUFA-based diets (Haptoglobin - Hp). Together, these data highlight the importance of early intervention with exercise to revert HFD-induced phenotypes and suggest some of the molecular mechanisms leading to the changes in the plasma proteome generated by high fat diet consumption. Web-based interactive visualizations are provided for this dataset (larancelab.com/hfd-exercise), which give insight into diet and exercise phenotypic interactions on the plasma proteome.

To identify novel autoantibodies of Takayasu arteritis (TAK) using HuProt array-based approach. A two-phase approach was adopted. In Phase I, serum samples collected from 40 TAK patients, 15 autoimmune disease patients, and 20 healthy subjects were screened to identify TAK-specific autoantibodies using human protein (HuProt) arrays. In Phase II, the identified candidate autoantibodies were validated with TAK-focused arrays using an additional cohort comprised of 109 TAK patients, 110 autoimmune disease patients, and 96 healthy subjects. Subsequently, the TAK-specific autoantibodies validated in Phase II were further confirmed using Western blot analysis. We identified and validated eight autoantibodies as potential TAK-specific diagnostic biomarkers, including anti-SPATA7, -QDPR, -SLC25A2, -PRH2, -DIXDC1, -IL17RB, -ZFAND4, and -NOLC1 antibodies, with AUC of 0.803, 0.801, 0.780, 0.696, 0.695, 0.678, 0.635 and 0.613, respectively. SPATA7 could distinguish TAK from healthy and disease controls with 73.4% sensitivity at 85.4% specificity, while QDPR showed 71.6% sensitivity at 86.4% specificity. SLC25A22 showed the highest sensitivity of 80.7%, but at lower specificity of 67.0%. In addition, PRH2, IL17RB and NOLC1 showed good specificities of 88.3%, 85.9% and 86.9%, respectively, but at lower sensitivities (<50%). Finally, DIXDC1 and ZFAND4 showed moderate performance as compared with the other autoantibodies. Using a decision tree model, we could reach a specificity of 94.2% with AUC of 0.843, a significantly improved performance as compared to that by each individual biomarker. The performance of three autoantibodies, namely anti-SPATA7, -QDPR and -PRH2, were successfully confirmed with Western blot analysis. Using this two-phase strategy, we identified and validated eight novel autoantibodies as TAK–specific biomarker candidates, three of which could be readily adopted in a clinical setting.

Giardia lamblia (G. lamblia) disease is a zoonosis with a-infection rate affecting the general population of the world. Despite the constant possibility of damage due to their own metabolism, G. lamblia have survived and evolved to adapt to various environments. However, research on energy-metabolism conversion in G. lamblia is limited. This study aimed to reveal the dynamic metabolism-conversion mechanism in G. lamblia under sugar starvation by detecting global lysine acetylation and 2-hydroxyisobutyrylation sites combined with quantitative proteome analyses. A total of 2999 acetylation sites on 956 proteins and 8877 2-hydroxyisobutyryl sites on 1546 proteins were quantified under sugar starvation. Integrated Kac and Khib data revealed that modified proteins were associated with arginine biosynthesis, glycolysis/gluconeogenesis, and alanine, aspartate, and glutamate metabolism. These findings suggested that lysine acetylation and 2-hydroxyisobutyrylation were ubiquitous and provided deep insight into the metabolism-conversion mechanism in G. lamblia under sugar starvation. Overall, these results can help understand the biology of G. lamblia infections and reveal the evolution rule from prokaryote to eukaryote.

Online Disinformation and Political Discourse: Applying a Human Rights Framework Research paper sysadmin 5 November 2019

Although some digital platforms now have an impact on more people’s lives than does any one state authority, the international community has been slow to hold to account these platforms’ activities by reference to human rights law.

This paper examines how human rights frameworks should guide digital technology.

Summary

• Online political campaigning techniques are distorting our democratic political processes. These techniques include the creation of disinformation and divisive content; exploiting digital platforms’ algorithms, and using bots, cyborgs and fake accounts to distribute this content; maximizing influence through harnessing emotional responses such as anger and disgust; and micro-targeting on the basis of collated personal data and sophisticated psychological profiling techniques. Some state authorities distort political debate by restricting, filtering, shutting down or censoring online networks.
• Such techniques have outpaced regulatory initiatives and, save in egregious cases such as shutdown of networks, there is no international consensus on how they should be tackled. Digital platforms, driven by their commercial impetus to encourage users to spend as long as possible on them and to attract advertisers, may provide an environment conducive to manipulative techniques.
• International human rights law, with its careful calibrations designed to protect individuals from abuse of power by authority, provides a normative framework that should underpin responses to online disinformation and distortion of political debate. Contrary to popular view, it does not entail that there should be no control of the online environment; rather, controls should balance the interests at stake appropriately.
• The rights to freedom of thought and opinion are critical to delimiting the appropriate boundary between legitimate influence and illegitimate manipulation. When digital platforms exploit decision-making biases in prioritizing bad news and divisive, emotion-arousing information, they may be breaching these rights. States and digital platforms should consider structural changes to digital platforms to ensure that methods of online political discourse respect personal agency and prevent the use of sophisticated manipulative techniques.
• The right to privacy includes a right to choose not to divulge your personal information, and a right to opt out of trading in and profiling on the basis of your personal data. Current practices in collecting, trading and using extensive personal data to ‘micro-target’ voters without their knowledge are not consistent with this right. Significant changes are needed.
• Data protection laws should be implemented robustly, and should not legitimate extensive harvesting of personal data on the basis of either notional ‘consent’ or the data handler’s commercial interests. The right to privacy should be embedded in technological design (such as by allowing the user to access all information held on them at the click of a button); and political parties should be transparent in their collection and use of personal data, and in their targeting of messages. Arguably, the value of personal data should be shared with the individuals from whom it derives.
• The rules on the boundaries of permissible content online should be set by states, and should be consistent with the right to freedom of expression. Digital platforms have had to rapidly develop policies on retention or removal of content, but those policies do not necessarily reflect the right to freedom of expression, and platforms are currently not well placed to take account of the public interest. Platforms should be far more transparent in their content regulation policies and decision-making, and should develop frameworks enabling efficient, fair, consistent internal complaints and content monitoring processes. Expertise on international human rights law should be integral to their systems.
• The right to participate in public affairs and to vote includes the right to engage in public debate. States and digital platforms should ensure an environment in which all can participate in debate online and are not discouraged from standing for election, from participating or from voting by online threats or abuse.

Diagnosing social behavioural dynamics of corruption Other resource dora.popova 8 December 2021

This interactive toolkit identifies the types of social expectations which sustain selected corrupt practices and provides behaviourally-informed recommendations for changing them.

When tackling a problem as complex as corruption, it is important to understand why and how people behave in different situations where corruption occurs. In contexts where it is easier to engage in corruption than avoid it, identifying the social expectations and informal rules which sustain corrupt practices can advance corruption prevention and deepen collective action.  

Behavioural approaches to corruption offer a better understanding of diverse social settings, group dynamics, power distribution, social motivations, and expectations that contribute to a more tolerant environment for certain forms of the phenomenon. They are also highly complementary to traditional corruption measures, which tend to focus on the enforcement of legal sanctions and deterrents. Behavioural approaches, especially those inspired by social norms theory, highlight complex social characteristics and informal rules of specific corrupt practices, and effectively support implementation of more dynamic context-specific anti-corruption interventions.

Since 2016, the Chatham House Africa programme’s Social Norms and Accountable Governance (SNAG) project has adopted a behavioural approach based on social norms methodology to investigate the social beliefs which motivate different forms of corruption. Drawing on the project’s extensive evidence-gathering and analysis, this toolkit offers users navigable behavioural mapping of contextual factors, beliefs, and expectations surrounding common corrupt practices. 

It aims to support anti-corruption actors in diagnosing informal rules and social expectations which sustain corruption in some societies. It also proposes behavioural-informed guidance for developing or adapting anti-corruption interventions and activities, so they account for informal rules of behaviour such as social norms. 
 
The toolkit supports users to:

• Identify whether and how widespread corrupt practices are motivated by social beliefs and expectations.

• Understand how society influences the types of corrupt activity individuals engage in, or avoid, and the factors informing these choices

• Integrate empirical evidence and behavioural insights into anti-corruption strategies from diagnostics to design, and eventual implementation and evaluation

The toolkit presents evidence from SNAG’s research into three key corrupt practices – bribery, embezzlement, and electoral fraud. Each was examined in the context of typical situations in which they occur, such as law enforcement, healthcare, the power sector, voting, and education while critical factors such as religion, gender, and ethnicity were considered. 

The toolkit presents an overview of specific contexts and behavioural features of the practices and provides behavioural-informed recommendations. It also contains pop-up features with definitions and explanations of key concepts. The toolkit is designed to be expandable, allowing further content and behavioural dynamics to be added.   

Jerad Eickhoff took his latest first step on Sunday morning at Spectrum Field. He threw a bullpen session, his first since sustaining a setback last month following carpal tunnel surgery in October.

Business Development in Madagascar: How to Enable Entrepreneurialism 15 November 2017 — 12:00PM TO 1:00PM Anonymous (not verified) 9 November 2017 Chatham House, London

Zimbabwe Futures 2030: Policy Priorities for Industrialization, Agri-Business and Tourism 6 June 2019 — 9:30AM TO 1:15PM Anonymous (not verified) 21 June 2019 Bulawayo, Zimbabwe

Economic Recovery and Anticorruption in South Africa: Assessing Progress on the Reform Agenda 4 December 2019 — 3:00PM TO 4:00PM Anonymous (not verified) 25 November 2019 Chatham House | 10 St James's Square | London | SW1Y 4LE

South Africa has significant economic potential based on its resource endowment, quality human capital and well-developed infrastructure compared to the region. However, the country’s economic growth rate has not topped 2 per cent since 2013, and in 2018, was below 1 per cent. This has put a strain on citizens and communities in a country that still suffers from structural inequality, poverty and high unemployment. Economic recovery and anti-corruption were the central pillars of President Cyril Ramaphosa’s 2019 electoral campaign and he has set an investment target of $100 billion. However, voters and investors alike are demanding faster and more visible progress from the country’s enigmatic leader who has a reputation for caution and calculation.

At this event, Professor Nick Binedell will discuss the progress of and opposition to the president’s economic reform agenda and the opportunities for international investment to support long term inclusive and sustainable growth in South Africa.

Attendance at this event is by invitation only.

Angola's Business Promise: Evaluating the Progress of Privatization and Other Economic Reforms 21 January 2020 — 2:30PM TO 3:30PM Anonymous (not verified) 16 January 2020 Chatham House | 10 St James's Square | London | SW1Y 4LE

Minister Nunes Júnior will discuss the progress of the Angolan government’s economic stabilization plans and business reform agenda including the privatization of some state-owned enterprises. These reforms could expand Angola’s exports beyond oil and stimulate new industries and more inclusive economic growth.

THIS EVENT IS NOW FULL AND REGISTRATION HAS CLOSED.

Thinking out loud: Is disinformation here to stay? 10 November 2022 — 6:00PM TO 6:45PM Anonymous (not verified) 25 October 2022 Chatham House

This event is postponed.

Have you ever wondered how Chatham House researchers approach the big deals that become research? Do you enjoy meeting other Chatham House members and engaging with questions that open your mind? ‘Thinking Out Loud’ invites a small group of members to a live, unscripted discussion with a Chatham House researcher. This in-person event is a way for researchers and members to think out loud to help shape ideas for future research.

Kate Jones, Associate Fellow, International Law Programme at Chatham House will pose some key questions facing how speech is governed in an online world:

• How has big tech influenced the way we think about speech and its limitations?

• Can disinformation be eliminated or even greatly reduced?

• Where should the responsibilities fall between government and business when it comes to speech regulation?

• What might the information landscape look like in 10 years’ time? Should that affect how we tackle disinformation today?

As with all members events, questions from the audience drive the conversation.

Director’s breakfast briefing: Shifts in European foreign policy since 9/11 14 October 2021 — 8:00AM TO 9:15AM Anonymous (not verified) 4 October 2021 Chatham House

Former MI6 chief, Sir Alex Younger, discusses shifts in European foreign policy since 9/11.

Former MI6 chief Sir Alex Younger, discusses shifts in European foreign policy since 9/11.

The dramatic events surrounding the withdrawal from Afghanistan demonstrates a profound shift in European security priorities since the beginning of the ‘war on terror’. Against the backdrop of the 20th anniversary of 9/11, former MI6 chief, Sir Alex Younger, discusses recent shifts in European foreign policy.

How has the focus on counterterrorism changed over the last two decades particularly in light of new and evolving strategic challenges? Why were many long-term objectives in Afghanistan left unachieved? Has the threat of terrorism changed across Europe? How has cooperation between security and intelligence services across the world changed particularly across the Atlantic? And, 20 years on, is the ‘war on terror’ really over?

This event is only open to Chatham House Partners and Major Corporate Members as well as selected giving circles of Chatham House. If you would like to attend, please RSVP to Linda Bedford at RSVP@chathamhouse.org.

Methods to shorten [¹⁸F]FDG Patlak PET imaging procedures ranging from 65–90 to 20–30 min after injection, using a population-averaged input function (PIF) scaled to patient-specific image-derived input function (IDIF) values, were recently evaluated. The aim of the present study was to explore the feasibility of ultrashort 10-min [¹⁸F]FDG Patlak imaging at 55–65 min after injection using a PIF combined with direct Patlak reconstructions to provide reliable quantitative accuracy of lung tumor uptake, compared with a full-duration 65-min acquisition using an IDIF. Methods: Patients underwent a 65-min dynamic PET acquisition on a long-axial-field-of-view (LAFOV) Biograph Vision Quadra PET/CT scanner. Subsequently, direct Patlak reconstructions and image-based (with reconstructed dynamic images) Patlak analyses were performed using both the IDIF (time to relative kinetic equilibrium between blood and tissue concentration (t*) = 30 min) and a scaled PIF at 30–60 min after injection. Next, direct Patlak reconstructions were performed on the system console using only the last 10 min of the acquisition, that is, from 55 to 65 min after injection, and a scaled PIF using maximum crystal ring difference settings of both 85 and 322. Tumor lesion and healthy-tissue uptake was quantified and compared between the differently obtained parametric images to assess quantitative accuracy. Results: Good agreement was obtained between direct- and image-based Patlak analyses using the IDIF (t* = 30 min) and scaled PIF at 30–60 min after injection, performed using the different approaches, with no more than 8.8% deviation in tumor influx rate value (K_i) (mean difference ranging from –0.0022 to 0.0018 mL/[min x g]). When direct Patlak reconstruction was performed on the system console, excellent agreement was found between the use of a scaled PIF at 30–60 min after injection versus 55–65 min after injection, with 2.4% deviation in tumor K_i (median difference, –0.0018 mL/[min x g]; range, –0.0047 to 0.0036 mL/[min x g]). For different maximum crystal ring difference settings using the scan time interval of 55–65 min after injection, only a 0.5% difference (median difference, 0.0000 mL/[min x g]; range, –0.0004 to 0.0013 mL/[min x g]) in tumor K_i was found. Conclusion: Ultrashort whole-body [¹⁸F]FDG Patlak imaging is feasible on an LAFOV Biograph Vision Quadra PET/CT system without loss of quantitative accuracy to assess lung tumor uptake compared with a full-duration 65-min acquisition. The ultrashort 10-min direct Patlak reconstruction with PIF allows for its implementation in clinical practice.