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Radiosensitization by Kinase Inhibition Revealed by Phosphoproteomic Analysis of Pancreatic Cancer Cells [Research]

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive cancers and known for its extensive genetic heterogeneity, high therapeutic resistance, and strong variation in intrinsic radiosensitivity. To understand the molecular mechanisms underlying radioresistance, we screened the phenotypic response of 38 PDAC cell lines to ionizing radiation. Subsequent phosphoproteomic analysis of two representative sensitive and resistant lines led to the reproducible identification of 7,800 proteins and 13,000 phosphorylation sites (p-sites). Approximately 700 p-sites on 400 proteins showed abundance changes after radiation in all cell lines regardless of their phenotypic sensitivity. Apart from recapitulating known radiation response phosphorylation markers such as on proteins involved in DNA damage repair, the analysis uncovered many novel members of a radiation-responsive signaling network that was apparent only at the level of protein phosphorylation. These regulated p-sites were enriched in potential ATM substrates and in vitro kinase assays corroborated 10 of these. Comparing the proteomes and phosphoproteomes of radiosensitive and -resistant cells pointed to additional tractable radioresistance mechanisms involving apoptotic proteins. For instance, elevated NADPH quinine oxidoreductase 1 (NQO1) expression in radioresistant cells may aid in clearing harmful reactive oxygen species. Resistant cells also showed elevated phosphorylation levels of proteins involved in cytoskeleton organization including actin dynamics and focal adhesion kinase (FAK) activity and one resistant cell line showed a strong migration phenotype. Pharmacological inhibition of the kinases FAK by Defactinib and of CHEK1 by Rabusertib showed a statistically significant sensitization to radiation in radioresistant PDAC cells. Together, the presented data map a comprehensive molecular network of radiation-induced signaling, improves the understanding of radioresistance and provides avenues for developing radiotherapeutic strategies.




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Sialylation of Asparagine 612 Inhibits Aconitase Activity during Mouse Sperm Capacitation; a Possible Mechanism for the Switch from Oxidative Phosphorylation to Glycolysis [Research]

After ejaculation, mammalian spermatozoa must undergo a process known as capacitation in order to successfully fertilize the oocyte. Several post-translational modifications occur during capacitation, including sialylation, which despite being limited to a few proteins, seems to be essential for proper sperm-oocyte interaction. Regardless of its importance, to date, no single study has ever identified nor quantified which glycoproteins bearing terminal sialic acid (Sia) are altered during capacitation. Here we characterize sialylation during mouse sperm capacitation. Using tandem MS coupled with liquid chromatography (LC–MS/MS), we found 142 nonreductant peptides, with 9 of them showing potential modifications on their sialylated oligosaccharides during capacitation. As such, N-linked sialoglycopeptides from C4b-binding protein, endothelial lipase (EL), serine proteases 39 and 52, testis-expressed protein 101 and zonadhesin were reduced following capacitation. In contrast, mitochondrial aconitate hydratase (aconitase; ACO2), a TCA cycle enzyme, was the only protein to show an increase in Sia content during capacitation. Interestingly, although the loss of Sia within EL (N62) was accompanied by a reduction in its phospholipase A1 activity, a decrease in the activity of ACO2 (i.e. stereospecific isomerization of citrate to isocitrate) occurred when sialylation increased (N612). The latter was confirmed by N612D recombinant protein tagged with both His and GFP. The replacement of Sia for the negatively charged Aspartic acid in the N612D mutant caused complete loss of aconitase activity compared with the WT. Computer modeling show that N612 sits atop the catalytic site of ACO2. The introduction of Sia causes a large conformational change in the alpha helix, essentially, distorting the active site, leading to complete loss of function. These findings suggest that the switch from oxidative phosphorylation, over to glycolysis that occurs during capacitation may come about through sialylation of ACO2.




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Multiomics Reveals Ectopic ATP Synthase Blockade Induces Cancer Cell Death via a lncRNA-mediated Phospho-signaling Network [Research]

The EGFR tyrosine kinase inhibitor gefitinib is commonly used for lung cancer patients. However, some patients eventually become resistant to gefitinib and develop progressive disease. Here, we indicate that ecto-ATP synthase, which ectopically translocated from mitochondrial inner membrane to plasma membrane, is considered as a potential therapeutic target for drug-resistant cells. Quantitative multi-omics profiling reveals that ecto-ATP synthase inhibitor mediates CK2-dependent phosphorylation of DNA topoisomerase IIα (topo IIα) at serine 1106 and subsequently increases the expression of long noncoding RNA, GAS5. Additionally, we also determine that downstream of GAS5, p53 pathway, is activated by ecto-ATP synthase inhibitor for regulation of programed cell death. Interestingly, GAS5-proteins interactomic profiling elucidates that GAS5 associates with topo IIα and subsequently enhancing the phosphorylation level of topo IIα. Taken together, our findings suggest that ecto-ATP synthase blockade is an effective therapeutic strategy via regulation of CK2/phospho-topo IIα/GAS5 network in gefitinib-resistant lung cancer cells.




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Identification of Microorganisms by Liquid Chromatography-Mass Spectrometry (LC-MS1) and in Silico Peptide Mass Libraries [Technological Innovation and Resources]

Over the past decade, modern methods of MS (MS) have emerged that allow reliable, fast and cost-effective identification of pathogenic microorganisms. Although MALDI-TOF MS has already revolutionized the way microorganisms are identified, recent years have witnessed also substantial progress in the development of liquid chromatography (LC)-MS based proteomics for microbiological applications. For example, LC-tandem MS (LC-MS2) has been proposed for microbial characterization by means of multiple discriminative peptides that enable identification at the species, or sometimes at the strain level. However, such investigations can be laborious and time-consuming, especially if the experimental LC-MS2 data are tested against sequence databases covering a broad panel of different microbiological taxa. In this proof of concept study, we present an alternative bottom-up proteomics method for microbial identification. The proposed approach involves efficient extraction of proteins from cultivated microbial cells, digestion by trypsin and LC–MS measurements. Peptide masses are then extracted from MS1 data and systematically tested against an in silico library of all possible peptide mass data compiled in-house. The library has been computed from the UniProt Knowledgebase covering Swiss-Prot and TrEMBL databases and comprises more than 12,000 strain-specific in silico profiles, each containing tens of thousands of peptide mass entries. Identification analysis involves computation of score values derived from correlation coefficients between experimental and strain-specific in silico peptide mass profiles and compilation of score ranking lists. The taxonomic positions of the microbial samples are then determined by using the best-matching database entries. The suggested method is computationally efficient – less than 2 mins per sample - and has been successfully tested by a test set of 39 LC-MS1 peak lists obtained from 19 different microbial pathogens. The proposed method is rapid, simple and automatable and we foresee wide application potential for future microbiological applications.




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Mutation-independent Proteomic Signatures of Pathological Progression in Murine Models of Duchenne Muscular Dystrophy [Research]

The absence of the dystrophin protein in Duchenne muscular dystrophy (DMD) results in myofiber fragility and a plethora of downstream secondary pathologies. Although a variety of experimental therapies are in development, achieving effective treatments for DMD remains exceptionally challenging, not least because the pathological consequences of dystrophin loss are incompletely understood. Here we have performed proteome profiling in tibialis anterior muscles from two murine DMD models (mdx and mdx52) at three ages (8, 16, and 80 weeks of age), all n = 3. High-resolution isoelectric focusing liquid chromatography-tandem MS (HiRIEF-LC–MS/MS) was used to quantify the expression of 4974 proteins across all 27 samples. The two dystrophic models were found to be highly similar, whereas multiple proteins were differentially expressed relative to WT (C57BL/6) controls at each age. Furthermore, 1795 proteins were differentially expressed when samples were pooled across ages and dystrophic strains. These included numerous proteins associated with the extracellular matrix and muscle function that have not been reported previously. Pathway analysis revealed multiple perturbed pathways and predicted upstream regulators, which together are indicative of cross-talk between inflammatory, metabolic, and muscle growth pathways (e.g. TNF, INF, NF-B, SIRT1, AMPK, PGC-1α, PPARs, ILK, and AKT/PI3K). Upregulation of CAV3, MVP and PAK1 protein expression was validated in dystrophic muscle by Western blot. Furthermore, MVP was upregulated during, but not required for, the differentiation of C2C12 myoblasts suggesting that this protein may affect muscle regeneration. This study provides novel insights into mutation-independent proteomic signatures characteristic of the dystrophic phenotype and its progression with aging.




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Global Proteome and Phosphoproteome Characterization of Sepsis-induced Kidney Injury [Research]

Sepsis-induced acute kidney injury (S-AKI) is the most common complication in hospitalized and critically ill patients, highlighted by a rapid decline of kidney function occurring a few hours or days after sepsis onset. Systemic inflammation elicited by microbial infections is believed to lead to kidney damage under immunocompromised conditions. However, although AKI has been recognized as a disease with long-term sequelae, partly because of the associated higher risk of chronic kidney disease (CKD), the understanding of kidney pathophysiology at the molecular level and the global view of dynamic regulations in situ after S-AKI, including the transition to CKD, remains limited. Existing studies of S-AKI mainly focus on deriving sepsis biomarkers from body fluids. In the present study, we constructed a mid-severity septic murine model using cecal ligation and puncture (CLP), and examined the temporal changes to the kidney proteome and phosphoproteome at day 2 and day 7 after CLP surgery, corresponding to S-AKI and the transition to CKD, respectively, by employing an ultrafast and economical filter-based sample processing method combined with the label-free quantitation approach. Collectively, we identified 2,119 proteins and 2950 phosphosites through multi-proteomics analyses. Among them, we identified an array of highly promising candidate marker proteins indicative of disease onset and progression accompanied by immunoblot validations, and further denoted the pathways that are specifically responsive to S-AKI and its transition to CKD, which include regulation of cell metabolism regulation, oxidative stress, and energy consumption in the diseased kidneys. Our data can serve as an enriched resource for the identification of mechanisms and biomarkers for sepsis-induced kidney diseases.




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Temporal Quantitative Proteomics of mGluR-induced Protein Translation and Phosphorylation in Neurons [Research]

At neuronal synapses, activation of group I metabotropic glutamate receptors (mGluR1/5) triggers a form of long-term depression (mGluR-LTD) that relies on new protein synthesis and the internalization of AMPA-type glutamate receptors. Dysregulation of these processes has been implicated in the development of mental disorders such as autism spectrum disorders and therefore merit a better understanding on a molecular level. Here, to study mGluR-induced signaling pathways, we integrated quantitative phosphoproteomics with the analyses of newly synthesized proteins via bio-orthogonal amino acids (azidohomoalanine) in a pulsed labeling strategy in cultured hippocampal neurons stimulated with DHPG, a specific agonist for group I mGluRs. We identified several kinases with important roles in DHPG-induced mGluR activation, which we confirmed using small molecule kinase inhibitors. Furthermore, changes in the AMPA receptor endocytosis pathway in both protein synthesis and protein phosphorylation were identified, whereby Intersectin-1 was validated as a novel player in this pathway. This study revealed several new insights into the molecular pathways downstream of group I mGluR activation in hippocampal neurons, and provides a rich resource for further analyses.




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Principles of electrospray ionization [Biophysical Methods]

Electrospray ionization is today the most widely used ionization technique in chemical and bio-chemical analysis. Interfaced with a mass spectrometer it allows to investigate the molecular composition of liquid samples. With electrospray a large variety of chemical substances can be ionized. There is no limitation in mass which enables even the investigation of large non-covalent protein complexes. Its high ionization efficiency profoundly changed bio-molecular sciences because proteins can be identified and quantified on trace amounts in a high throughput fashion. This review article focusses mainly on the exploration of the underlying ionization mechanism. Some ionization characteristics are discussed which are related to this mechanism. Typical spectra of peptides, proteins and non-covalent complexes are shown and the quantitative character of spectra is highlighted. Finally the possibilities and limitations in measuring the association constant of bivalent non-covalent complexes are described.




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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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Transcriptome and secretome analysis of intra-mammalian life-stages of the emerging helminth pathogen, Calicophoron daubneyi reveals adaptation to a unique host environment. [Research]

Paramphistomosis, caused by the rumen fluke, Calicophoron daubneyi, is a parasitic infection of ruminant livestock which has seen a rapid rise in prevalence throughout Western Europe in recent years. Following ingestion of metacercariae (parasite cysts) by the mammalian host, newly-excysted juveniles (NEJs) emerge and invade the duodenal submucosa which causes significant pathology in heavy infections. The immature larvae then migrate upwards, along the gastrointestinal tract, and enter the rumen where they mature and begin to produce eggs. Despite their emergence, and sporadic outbreaks of acute disease, we know little about the molecular mechanisms used by C. daubneyi to establish infection, acquire nutrients and to avoid the host immune response. Here, transcriptome analysis of four intra-mammalian life-cycle stages, integrated with secretome analysis of the NEJ and adult parasites (responsible for acute and chronic disease respectively), revealed how the expression and secretion of selected families of virulence factors and immunomodulators are regulated in accordance with fluke development and migration. Our data show that whilst a family of cathepsins B with varying S2 sub-site residues (indicating distinct substrate specificities) are differentially secreted by NEJs and adult flukes, cathepsins L and F are secreted in low abundance by NEJs only. We found that C. daubneyi has an expanded family of aspartic peptidases, which is up-regulated in adult worms, although they are underrepresented in the secretome. The most abundant proteins in adult fluke secretions were helminth defence molecules (HDMs) that likely establish an immune environment permissive to fluke survival and/or neutralise pathogen-associated molecular patterns (PAMPs) such as bacterial lipopolysaccharide in the microbiome-rich rumen. The distinct collection of molecules secreted by C. daubneyi allowed the development of the first coproantigen-based ELISA for paramphistomosis which, importantly, did not recognise antigens from other helminths commonly found as co-infections with rumen fluke.




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Blockade of High-Fat Diet Proteomic Phenotypes using Exercise as Prevention or Treatment [Technological Innovation and Resources]

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.




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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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PTM-Shepherd: analysis and summarization of post-translational and chemical modifications from open search results [Technological Innovation and Resources]

Open searching has proven to be an effective strategy for identifying both known and unknown modifications in shotgun proteomics experiments. Rather than being limited to a small set of user-specified modifications, open searches identify peptides with any mass shift that may correspond to a single modification or a combination of several modifications. Here we present PTM-Shepherd, a bioinformatics tool that automates characterization of PTM profiles detected in open searches based on attributes such as amino acid localization, fragmentation spectra similarity, retention time shifts, and relative modification rates. PTM-Shepherd can also perform multi-experiment comparisons for studying changes in modification profiles, e.g. in data generated in different laboratories or under different conditions. We demonstrate how PTM-Shepherd improves the analysis of data from formalin-fixed paraffin-embedded samples, detects extreme underalkylation of cysteine in some datasets, discovers an artefactual modification introduced during peptide synthesis, and uncovers site-specific biases in sample preparation artifacts in a multi-center proteomics profiling study.




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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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In depth characterization of the Staphylococcus aureus phosphoproteome reveals new targets of Stk1 [Research]

Staphylococcus aureus is a major cause of infections worldwide and infection results in a variety of diseases. As of no surprise, protein phosphorylation is an important game player in signaling cascades and has been shown to be involved in S. aureus virulence. Albeit long neglected, eukaryotic-type serine/threonine kinases in S. aureus have been implicated in this complex signaling cascades. Due to the sub-stoichiometric nature of protein phosphorylation and a lack of suitable analysis tools, the knowledge of these cascades is however, to date, still limited.

Here, were apply an optimized protocol for efficient phosphopeptide enrichment via Fe3+-IMAC followed by LC-MS/MS to get a better understanding of the impact of protein phosphorylation on the complex signaling networks involved in pathogenicity. By profiling a serine/threonine kinase and phosphatase mutant from a methicillin-resistant S. aureus mutant library, we generated the most comprehensive phosphoproteome dataset of S. aureus to date, aiding a better understanding of signaling in bacteria. With the identification of 3800 class I p-sites we were able to increase the number of identifications by more than 21 times compared to recent literature. In addition, we were able to identify 74 downstream targets of the only reported eukaryotic-type Ser/Thr kinase of the S. aureus strain USA300, Stk1. This work allowed an extensive analysis of the bacterial phosphoproteome and indicates that Ser/Thr kinase signaling is far more abundant than previously anticipated in S. aureus.




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Unraveling the MAX2 Protein Network in Arabidopsis thaliana: Identification of the Protein Phosphatase PAPP5 as a Novel MAX2 Interactor [Research]

The F-box protein MORE AXILLARY GROWTH 2 (MAX2) is a central component in the signaling cascade of strigolactones (SLs) as well as of the smoke derived karrikins (KARs) and the so far unknown endogenous KAI2 ligand (KL). The two groups of molecules are involved in overlapping and unique developmental processes, and signal-specific outcomes are attributed to perception by the paralogous α/β-hydrolases DWARF14 (D14) for SL and KARRIKIN INSENSITIVE 2/ HYPOSENSITIVE TO LIGHT (KAI2/HTL) for KAR/KL. Additionally, depending on which receptor is activated, specific members of the SUPPRESSOR OF MAX2 1 (SMAX1) – LIKE (SMXL) family control KAR/KL and SL responses. As proteins that function in the same signal transduction pathway often occur in large protein complexes, we aimed at discovering new players of the MAX2, D14 and KAI2 protein network by tandem affinity purification using Arabidopsis cell cultures. When using MAX2 as a bait, various proteins were co-purified among which general components of the Skp1-Cullin-F-box complex and members of the CONSTITUTIVE PHOTOMORPHOGENIC 9 signalosome. Here, we report the identification of a novel interactor of MAX2, a type 5 serine/threonine protein phosphatase, designated PHYTOCHROME-ASSOCIATED PROTEIN PHOSPHATASE 5 (PAPP5). Quantitative affinity purification pointed at PAPP5 as being more present in KAI2 rather than D14 protein complexes. In agreement, mutant analysis suggests that PAPP5 modulates KAR/KL-dependent seed germination in suboptimal conditions and seedling development. Additionally, a phosphopeptide enrichment experiment revealed that PAPP5 might dephosphorylate MAX2 in vivo independently of the synthetic strigolactone analog, rac-GR24. Together, by analyzing the protein complexes to which MAX2, D14 and KAI2 belong, we revealed a new MAX2 interactor, PAPP5, that might act through dephosphorylation of MAX2 to control mainly KAR/KL- related phenotypes and, hence, provide another link with the light pathway.




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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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High-throughput and site-specific N-glycosylation analysis of human alpha-1-acid glycoprotein offers a great potential for new biomarker discovery [Research]

Alpha-1-acid glycoprotein (AGP) is an acute phase glycoprotein in blood, which is primarily synthetized in the liver and whose biological role is not completely understood. It consists of 45% carbohydrates that are present in the form of five N-linked complex glycans. AGP N-glycosylation was shown to be changed in many different diseases and some changes appear to be disease-specific, thus it has a great diagnostic and prognostic potential. However, AGP glycosylation was mainly analyzed in small cohorts and without detailed site-specific glycan information. Here, we developed a cost-effective method for a high-throughput and site-specific N-glycosylation LC-MS analysis of AGP which can be applied on large cohorts, aid in search for novel disease biomarkers and enable better understanding of AGP’s role and function in health and disease. The method does not require isolation of AGP with antibodies and affinity chromatography, but AGP is enriched by acid precipitation from 5 μl of bloodplasma in a 96 well format. After trypsinization, AGP glycopeptides are purified using a hydrophilic interaction chromatography based solid-phase extraction and analyzed by RP-LC-ESI-MS. We used our method to show for the first time that AGP N-glycan profile is stable in healthy individuals (14 individuals in 3 time points), which is a requirement for evaluation of its diagnostic potential. Furthermore, we tested our method on a population including individuals with registered hyperglycemia in critical illness (59 cases and 49 controls), which represents a significantly increased risk of developing type 2 diabetes. Individuals at higher risk of diabetes presented increased N-glycan branching on AGP’s second glycosylation site and lower sialylation of N-glycans on AGP’s third and AGP1’s fourth glycosylation site. Although this should be confirmed on a larger prospective cohort, it indicates that site-specific AGP N-glycan profile could help distinguish individuals who are at risk of type 2 diabetes.




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Phosphorylation of SMURF2 by ATM exerts a negative feedback control of DNA damage response [DNA and Chromosomes]

Timely repair of DNA double-strand breaks (DSBs) is essential to maintaining genomic integrity and preventing illnesses induced by genetic abnormalities. We previously demonstrated that the E3 ubiquitin ligase SMURF2 plays a critical tumor suppressing role via its interaction with RNF20 (ring finger protein 20) in shaping chromatin landscape and preserving genomic stability. However, the mechanism that mobilizes SMURF2 in response to DNA damage remains unclear. Using biochemical approaches and MS analysis, we show that upon the onset of the DNA-damage response, SMURF2 becomes phosphorylated at Ser384 by ataxia telangiectasia mutated (ATM) serine/threonine kinase, and this phosphorylation is required for its interaction with RNF20. We demonstrate that a SMURF2 mutant with an S384A substitution has reduced capacity to ubiquitinate RNF20 while promoting Smad3 ubiquitination unabatedly. More importantly, mouse embryonic fibroblasts expressing the SMURF2 S384A mutant show a weakened ability to sustain the DSB response compared with those expressing WT SMURF2 following etoposide treatment. These data indicate that SMURF2-mediated RNF20 ubiquitination and degradation controlled by ataxia telangiectasia mutated–induced phosphorylation at Ser384 constitutes a negative feedback loop that regulates DSB repair.




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Phillies, Sean Rodriguez agree to Minors deal

The Phillies continued to bolster their infield depth on Friday by signing versatile veteran Sean Rodriguez to a Minor League contract with an invite to big league Spring Training, MLB.com has learned.




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Phillies land Realmuto for 3 players, int'l money

The Phillies acquired All-Star catcher J.T. Realmuto from the Marlins on Thursday for catcher Jorge Alfaro, right-hander Sixto Sanchez, left-hander Will Stewart and $250,000 in international bonus slot money, the latest move in a busy and ambitious offseason for a team eager to return to the postseason.




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Predicting the Phillies' Opening Day roster

Phillies pitchers and catchers have their first workout Wednesday morning at Carpenter Complex. Almost anything can happen between Wednesday and Opening Day. That said, here is a very early prediction of the Phillies' Opening Day roster, knowing the Phillies remain in the hunt to sign Bryce Harper or Manny Machado.




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Realmuto 'excited' to compete for title with Phils

The Phillies introduced J.T. Realmuto, their new All-Star catcher, in a news conference Tuesday at the team's Spring Training complex in Clearwater, Fla.




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Phillies can still win the offseason

We're reluctant to finalize our list of offseason winners because, as you may have heard, there are some prominent unsigned free agents. Not just Bryce Harper and Manny Machado, either.




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MacPhail: Phils are 'uniquely poised right now'

Phillies president Andy MacPhail opened a 28-minute press conference on Friday afternoon at Spectrum Field with facts and figures about investments the organization made the past few seasons as the team wallowed at the bottom of the National League. Then MacPhail talked a lot about Bryce Harper and Manny Machado as well as manager Gabe Kapler.




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Who will hit second and third for Phillies?

Phillies manager Gabe Kapler believes the two most important spots in a lineup are the Nos. 2 and 4 holes. Rhys Hoskins and Carlos Santana hit there most of last season. But with J.T. Realmuto, Andrew McCutchen and Jean Segura joining the Phillies in the offseason, Kapler has more options.




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Segura moving forward with contending Phillies

Jean Segura became one of the Phillies' most notable offseason acquisitions, a two-time All-Star expected to give the organization its best overall production at shortstop since Jimmy Rollins left town, in part because of a little brawl he had late last season with Mariners teammate Dee Gordon.




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Phillies' Top 30 Prospects list

Who do the Phillies have in the pipeline? Get scouting reports, video, stats, projected ETAs and more for Philly's Top 30 Prospects on MLBPipeline.com's Prospect Watch.




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The Phillies' Spring Training battle to watch

The next five weeks will see lots of shuffling on Major League rosters. Here are the most intriguing positional battles on each of the 30 MLB clubs.




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Talks 'intensifying' between Harper, Phillies

The Phillies have been the favorites in the Bryce Harper sweepstakes for months, and that speculation heated up over the weekend.




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Here are the Phillies' Top 30 Prospects

The Phillies list isn't quite as strong as it once was because of the Realmuto deal, but there's still some very good talent at the top and some exciting players on the rise.




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With Manny off market, Phils' focus on Harper

Bryce Harper is the final superstar standing for the Phillies.




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Test for syphilis in people with possible symptoms, says UKHSA, as cases rise




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Ramaphosa Has Won the Battle. But Can He Win the War?

Ramaphosa Has Won the Battle. But Can He Win the War? Expert comment sysadmin 21 December 2017

Cyril Ramaphosa is taking charge of South Africa’s ruling party, the ANC, at its weakest point in post-apartheid history. Expectations couldn’t be higher.

Cyril Ramaphosa during the announcement of new party leadership at the 5th African National Congress (ANC) national conference. Photo by Alet Pretorius/Gallo Images/Getty Images

Ramaphosa ran for the leadership of the ANC on a platform of party renewal, economic recovery, and building the capacity of the state. But Jacob Zuma remains the President of South Africa and, under the constitution, can stay in office until elections in 2019. Therefore, meeting expectations on economic recovery will depend on Ramaphosa taking the presidency – and he has a number of political battles to face before that becomes reality.

To begin with, Ramaphosa and his supporters did not win a total victory at the elective conference. The presidency was only one position in the senior cadre – the co-called ‘top six’ – that was elected. This body is now split evenly between Ramaphosa and his allies, and those that supported his opponent Dr Nkosazana Dlamini-Zuma - Jacob Zuma’s preferred successor. This creates two centres of power in the ANC, limiting what Ramaphosa will be able to achieve from within the party.

Although there is significant pressure from the electorate to remove Zuma from national office, actually doing so will be difficult. Zuma’s predecessor Thabo Mbeki was removed from the national presidency before his term was up when the National Executive Committee (NEC) of the party recalled him from office following Zuma’s assumption of party leadership. But this option may not be available to Ramaphosa. The split within the ‘top six’ and new NEC will make it difficult to present an ultimatum to Zuma. His loyalists will not want a witch hunt within the party.

Corruption and elitism within the party

Much of the tension centres on questions of corruption, the dominant political issue in South Africa at the moment. In the build up to the elective conference Gwede Mantashe - now national chairperson - admitted that “The biggest challenge from where we’re sitting is the image and the reputation of the ANC. The ANC is seen as equal to corruption and looting.” Ramaphosa made anti-corruption initiatives a centrepiece of his campaign, including the establishment of a judicial commission and rapid action to investigate and prosecute the guilty.

But the split within the party may undermine the credibility of these promises. Ramaphosa’s problem is that some of the new ‘top six’ - including Deputy President David Mabuza, and Secretary General Ace Magashule – would be high on the list of those the electorate want to see investigated. Party resistance may restrict the extent to which Ramaphosa can demonstrate a comprehensive break from the past.

Corruption within the party goes far deeper than the headline cases of ‘state capture’ and expropriation. At a branch level, access to political power has become the primary means of access to economic resource. It is a process of selective patronage that differentiates between those who are ‘in’ from those who aren’t. At its broadest, this type of corruption has created a mistrust of the ANC and the new economic elite that the party has created around it – including Ramaphosa himself.

Having lost out to Mbeki in the fight to succeed Mandela despite being the favourite for the job, Ramaphosa spearheaded the ANC’s deployment of cadres in business. He has become one of the country’s richest men, and a highly sought after board member by South Africa’s largest companies across mining, telecoms, and logistics.

One of his biggest challenges will be to remove the perception of elitism as his senior position within the party and economy has given rise to mistrust from a grass roots level. The political tussle at the conference was also largely driven by a small number of the party elite being able to control large groups of delegate votes. The nature of political competition within the party is symptomatic of the ANCs electoral dominance in the early days of the nation’s democracy. But this support is now far less certain, and the party cannot afford to become complacent.

Resetting the relationship with business

Ramaphosa’s business dealings may mean he has to walk a fine line in censuring his colleagues for making money from politics. But it may also be a significant opportunity for the party to reset its relationship with the private sector. Under Mbeki, relations between the ANC and business were distant, but characterized by recognition of mutual dependence.

Under Zuma this relationship deteriorated, and the President demonstrated he was willing to make decisions to boost his political power irrespective of economic consequences. Ramaphosa could, for the first time, truly align the interests of business and government, without abandoning his transformative policy agenda.

At an ANC regional economic colloquium in Johannesburg in November Ramaphosa outlined his ten-point economic plan. It would deliver the party’s adopted mantra of ‘radical economic transformation’, but through broadly neo-liberal policies on private business development and state-owned enterprise reform to allow private capital to co-invest.

He took the ethos and principles of the Freedom Charter – the 1955 statement of core ANC principles – and applied them to a modernising economy. Talk of a ‘new deal’, productive partnerships in the mining sector, and an emphasis on job creation in manufacturing will woo investors. The rand surged upon his election.

But Ramaphosa will not be able to deliver on the economic demands of the country until he is in the office of the presidency - and Zuma still holds many of the cards. Ramaphosa can promise his followers potential power and government positions in future, but Zuma can still offer them now.

Removing Zuma will require skilful internal party politicking, and Ramaphosa will need to limit the fallout – he cannot afford to further damage the credibility of the party before it faces the electorate in 2019. He has won the battle, but the outcome of the war is far from certain.




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Ramaphosa Must Act Fast With New Mandate in South Africa

Ramaphosa Must Act Fast With New Mandate in South Africa Expert comment sysadmin 23 May 2019

In the wake of South Africa’s election, political constraints will ebb momentarily. The president should seize the opportunity to deliver meaningful change.

Cyril Ramaphosa addresses the crowd during an ANC election victory rally in Johannesburg. Photo via Getty Images.

On 25 May, Cyril Ramaphosa will be inaugurated as president of South Africa, having dragged the African National Congress (ANC) over the line in the 8 May election. The ANC gained a 57 per cent majority, its lowest vote since 1994, its status as national liberator deeply eroded by successive corruption scandals. Only Ramaphosa’s personal popularity stopped it haemorrhaging more support.

His sustained action against corrupt public servants and promises of job-creating economic growth has attracted support from beyond the ANC’s base, including a significant minority of white voters, and generated significant international goodwill. Ramaphosa now has a short window of opportunity to reset social democracy in South Africa before the political cycle of municipal, party and national elections from 2021 to 2024 forces his attention back to party politics.

Defining ‘Ramaphosa-ism’

But personal popularity is fickle, and goodwill alone will not turn around the ailing economy. To attract investment and keep the electorate on side, Ramaphosa’s government needs to move beyond pragmatic crisis responses and articulate a clear, shared vision for how market intervention can allow the economy to grow while simultaneously delivering social transformation.

Growth will be hard to achieve in the short term. The economy is expected to grow 1.2% in 2019 and 1.5% in 2020, according to the IMF. Consumer confidence remains subdued, and a decade of declining GDP per capita and increasing inequality has put a strain on households. A ‘fiscal stimulus’ in 2018 delivered very little new government spending, and over the past 10 years, the government wage bill has increased three times higher than the rate of inflation.

Eskom, the state electricity provider, has debts equating to the GDP of Latvia and is not the only state-owned enterprise (SOE) that has required bailing out by the government. There are plans to break up Eskom into three separate entities but calls for deeper reform – or even privatization – are growing.

The president’s responses to these challenges will go a long way to defining ‘Ramaphosa-ism’ and the role of government in pursuing equitable economy growth.

Economic expectations under Ramaphosa

Ramaphosa was a champion of the introduction of a minimum wage and a proponent of the National Development Plan, which relies on growth to drive job creation. His support for land reform is an individual conviction as much as it is a party line, although his views are softer than many in the party, with state-owned land being the initial target.

Investor uncertainty on land tenure and regulations in mining will need to be addressed through passing key pieces of legislation on land reform and the revised Mining and Petroleum Resources Development Act.

Where Ramaphosa differs from his predecessors is his links with business. Thabo Mbeki enjoyed a relationship of mutual respect with business; this disintegrated under Jacob Zuma. Ramaphosa, however, is part of South Africa’s business community, having founded the Shanduka Group, with investments in multiple sectors including retail, telecoms and extractives, and served as chairman of MTN and Bidvest. As president, he has surrounded himself with close economic advisers from business and banking.

In the short term, anti-corruption measures and competent appointments will ease investor woes. In the long term, there is a need to improve the ease of doing business, including labour market reforms, and to make South Africa a more competitive business environment by reducing the hold of large conglomerates on the economy. Ramaphosa may also make greater use of public-private partnerships for large projects.

Political constraints

Ramaphosa faces few immediate political challenges. The ANC is still deeply divided, but although Ramaphosa does not enjoy the ideological support of the entire party, his opponents are leaderless post-Zuma, and have been unable to offer a coherent alternative. ANC Secretary General Ace Magashule has fallen into the role of interim figurehead of this faction, and allegations of corruption would make it difficult for him to aspire to national leadership.

The need to avoid splits before the election meant Ramaphosa had to make concessions, and his first cabinet in February 2018 included opponents and those accused of corruption or incompetence, such as Malusi Gigaba and Bathabile Dlamini. Such concessions to political opponents are unlikely to continue after the election.

Meanwhile, opposition parties made some advances in the election, but where Zuma was an easy target, they are still grappling with how to confront Ramaphosa. The party with the biggest gains was the Economic Freedom Fighters, whose increase of just over 4 points from the last election gave it 11 per cent of the vote this time. They will likely continue to be an effective disruptor. Ramaphosa may also be challenged by trade unions on his reforms, notably over any break-up of SOEs.

But the biggest and most immediate external political challenge for Ramaphosa will be rebuilding trust between government and society, in a context where social protest has become an alternative form of political participation. A turnout of 65 per cent may be considered normal in Western democracies but is a notable drop for a country as politicized as South Africa, driven by frustration and a sense of exclusion as much as apathy. Turnout by young people was even lower.

Achieving the vision

South Africa has all the platforms it needs to project its renewal and attract vital external investment – it is a non-permanent member of the UN Security Council, it will take over as chair of the African Union in 2020, it is a member of BRICS and it is the only African member of the G20. But in the recent past, it has struggled to tell a coherent story about its vision for the future and offer to the world.

In the immediate wake of the election, internal and external political constraints will ebb. Ramaphosa must act fast to deliver results before the election cycle starts again. To attract much needed investment stimulus, he will not only need to articulate and market his vision for South Africa, but also outline how he plans to achieve it.




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RCP warns over shortage of stroke physicians




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C-X-C Motif Chemokine Receptor 4-Directed Scintigraphy Using [99mTc]Tc-Pentixatec in Primary Aldosteronism: A Proof-of-Concept Study

C-X-C motif chemokine receptor 4 (CXCR4)–directed imaging has gained clinical interest in aiding clinical diagnostics in primary aldosteronism (PA). We retrospectively evaluated the feasibility of CXCR4-directed scintigraphy using the novel CXCR-4 ligand [99mTc]Tc-pentixatec in patients with PA. Methods: Six patients (mean age ± SD, 49 ± 15 y) underwent CXCR4-directed scintigraphy (including planar imaging and SPECT/CT) 30, 120, and 240 min after injection of 435 ± 50 MBq of [99mTc]Tc-pentixatec. Adrenal CXCR4 expression was analyzed by calculating lesion-to-contralateral ratios (LCRs). Imaging results were correlated to clinical information. Histopathology and clinical follow-up served as the standard of reference. Results: Three subjects showed lateralization of adrenal tracer accumulation, with a mean maximum lesion-to-contralateral ratio of 1.65 (range, 1.52–1.70), which correlated with morphologic findings on CT. One individual underwent adrenalectomy and presented with complete biochemical and clinical remission at follow-up. Histopathologic workup confirmed unilateral aldosterone-producing adenoma. Conclusion: [99mTc]Tc-pentixatec scintigraphy with SPECT in patients with PA is feasible and might offer a valuable alternative to CXCR4-directed imaging with [68Ga]Ga-pentixafor PET.




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Preclinical Evaluation of 177Lu-OncoFAP-23, a Multivalent FAP-Targeted Radiopharmaceutical Therapeutic for Solid Tumors

Fibroblast activation protein (FAP) is abundantly expressed in the stroma of most human solid tumors. Clinical-stage radiolabeled FAP ligands are increasingly used as tools for the detection of various cancer lesions. To unleash the full therapeutic potential of FAP-targeting agents, ligands need to remain at the tumor site for several days after administration. We recently described the discovery of OncoFAP, a high-affinity small organic ligand of FAP with a rapid accumulation in tumors and low uptake in healthy tissues in cancer patients. Trimerization of OncoFAP provided a derivative (named TriOncoFAP, or OncoFAP-23) with improved FAP affinity. In this work, we evaluated the tissue biodistribution profile and the therapeutic performance of OncoFAP-23 in tumor-bearing mice. Methods: OncoFAP-23 was radiolabeled with the theranostic radionuclide 177Lu. Preclinical experiments were conducted on mice bearing SK-RC-52.hFAP (BALB/c nude mice) or CT-26.hFAP (BALB/c mice) tumors. 177Lu-OncoFAP and 177Lu-FAP-2286 were included in the biodistribution study as controls. Toxicologic evaluation was performed on Wistar rats and CD1 mice by injecting high doses of OncoFAP-23 or its cold-labeled counterpart, respectively. Results: 177Lu-OncoFAP-23 emerged for its best-in-class biodistribution profile, high and prolonged tumor uptake (i.e., ~16 percentage injected dose/g at 96 h), and low accumulation in healthy organs, which correlates well with its potent single-agent anticancer activity at low levels of administered radioactivity. Combination treatment with the tumor-targeted interleukin 2 (L19-IL2, a clinical-stage immunocytokine) further expands the therapeutic window of 177Lu-OncoFAP-23 by potentiating its in vivo antitumor activity. Proteomics studies revealed a potent tumor-directed immune response on treatment with the combination. OncoFAP-23 and natLu-OncoFAP-23 exhibited a favorable toxicologic profile, without showing any side effects or signs of toxicity. Conclusion: OncoFAP-23 presents enhanced tumor uptake and tumor retention and low accumulation in healthy organs, findings that correspond to a strongly improved in vivo antitumor efficacy. The data presented in this work support the clinical development of 177Lu-OncoFAP-23 for the treatment of FAP-positive solid tumors.




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[68Ga]Ga-RAYZ-8009: A Glypican-3-Targeted Diagnostic Radiopharmaceutical for Hepatocellular Carcinoma Molecular Imaging--A First-in-Human Case Series

To date, the imaging and diagnosis of hepatocellular carcinoma (HCC) rely on CT/MRI, which have well-known limitations. Glypican-3 (GPC3) is a cell surface receptor highly expressed by HCC but not by normal or cirrhotic liver tissue. Here we report initial clinical results of GPC3-targeted PET imaging with [68Ga]Ga-DOTA-RYZ-GPC3 (RAYZ-8009), a peptide-based GPC3 ligand in patients with known or suspected HCC. Methods: [68Ga]Ga-RAYZ-8009 was obtained after labeling the peptide precursor with 68Ga from a 68Ge/68Ga generator and heating at 90°C for 10 min followed by sterile filtration. After administration of [68Ga]Ga-RAYZ-8009, a dynamic or static PET/CT scan was acquired between 45 min and 4 h after administration. Radiotracer uptake was measured by SUVs for the following tissues: suspected or actual HCC or hepatoblastoma lesions, non–tumor-bearing liver, renal cortex, blood pool in the left ventricle, and gastric fundus. Additionally, tumor–to–healthy-liver ratios (TLRs) were calculated. Results: Twenty-four patients (5 patients in the dynamic protocol; 19 patients in the static protocol) were scanned. No adverse events occurred. Two patients had no lesion detected and did not have HCC during follow-up. In total, 50 lesions were detected and analyzed. The mean SUVmax of these lesions was 19.6 (range, 2.7–95.3), and the mean SUVmean was 10.1 (range, 1.0–49.2) at approximately 60 min after administration. Uptake in non–tumor-bearing liver and blood pool rapidly decreased over time and became negligible 45 min after administration (mean SUVmean, <1.6), with a continuous decline to 4 h after administration (mean SUVmean, 1.0). The opposite was observed for HCC lesions, for which SUVs and TLRs continuously increased for up to 4 h after administration. In individual lesion analysis, TLR was the highest between 60 and 120 min after administration. Uptake in the gastric fundus gradually increased for up to 45 min (to an SUVmax of 31.3) and decreased gradually afterward. Conclusion: [68Ga]Ga-RAYZ-8009 is safe and allows for high-contrast imaging of GPC3-positive HCC, with rapid clearance from most normal organs. Thereby, [68Ga]Ga-RAYZ-8009 is promising for HCC diagnosis and staging. Further research is warranted.




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Optimizing the Therapeutic Index of sdAb-Based Radiopharmaceuticals Using Pretargeting

Single-domain antibodies (sdAbs) demonstrate favorable pharmacokinetic profiles for molecular imaging applications. However, their renal excretion and retention are obstacles for applications in targeted radionuclide therapy (TRT). Methods: Using a click-chemistry–based pretargeting approach, we aimed to reduce kidney retention of a fibroblast activation protein α (FAP)–targeted sdAb, 4AH29, for 177Lu-TRT. Key pretargeting parameters (sdAb-injected mass and lag time) were optimized in healthy mice and U87MG (FAP+) xenografts. A TRT study in a pancreatic ductal adenocarcinoma (PDAC) patient-derived xenograft (PDX) model was performed as a pilot study for sdAb-based pretargeting applications. Results: Modification of 4AH29 with trans-cyclooctene (TCO) moieties did not modify the sdAb pharmacokinetic profile. A 200-µg injected mass of 4AH29-TCO and an 8-h lag time for the injection of [177Lu]Lu-DOTA-PEG7-tetrazine resulted in the highest kidney therapeutic index (2.0 ± 0.4), which was 5-fold higher than that of [177Lu]Lu-DOTA-4AH29 (0.4 ± 0.1). FAP expression in the tumor microenvironment was validated in a PDAC PDX model with both immunohistochemistry and PET/CT imaging. Mice treated with the pretargeting high-activity approach (4AH29-TCO + [177Lu]Lu-DOTA-PEG7-tetrazine; 3 x 88 MBq, 1 injection per week for 3 wk) demonstrated prolonged survival compared with the vehicle control and conventionally treated ([177Lu]Lu-DOTA-4AH29; 3 x 37 MBq, 1 injection per week for 3 wk) mice. Mesangial expansion was reported in 7 of 10 mice in the conventional cohort, suggesting treatment-related kidney morphologic changes, but was not observed in the pretargeting cohort. Conclusion: This study validates pretargeting to mitigate sdAbs’ kidney retention with no observation of morphologic changes on therapy regimen at early time points. Clinical translation of click-chemistry–based pre-TRT is warranted on the basis of its ability to alleviate toxicities related to biovectors’ intrinsic pharmacokinetic profiles. The absence of representative animal models with extensive stroma and high FAP expression on cancer-associated fibroblasts led to a low mean tumor-absorbed dose even with high injected activity and consequently to modest survival benefit in this PDAC PDX.




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Amazon starts air drone deliveries near Phoenix

Amazon Prime Air drone deliveries are underway and delivering small packages within an hour in the West Valley of the Phoenix metro area.




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SS United States to be towed from Phila., launching transition into artificial reef

The historic ocean liner SS United States, whose fate had been in limbo for years, will begin its transition into the world's largest sunken artificial reef beginning this week in Philadelphia, its owner says.




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Nu Quantum Unveils Qubit-Photon Interface to Enable Distributed Quantum Computing Networks

CAMBRIDGE, England, Oct. 15, 2024 — Nu Quantum has announced a proof-of-principle prototype that advances the development of modular, distributed quantum computers by enabling connections across different qubit modalities and […]

The post Nu Quantum Unveils Qubit-Photon Interface to Enable Distributed Quantum Computing Networks appeared first on HPCwire.




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‘Loopholes’ let warring parties use incendiary weapons in Ukraine, Middle East: HRW

Loopholes in international laws governing the use of incendiary weapons in warfare are allowing warring parties in Ukraine and the Middle East to exploit the use of such weapons without adequately protecting civilians.




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Defense helps Miami Dolphins beat Los Angeles Rams, snap three-game skid

Linebacker Quinton Bell and Miami Dolphins defenders deleted drives and put the Los Angeles Rams offense in quicksand, holding them without a touchdown to propel a primetime victory and snap a three-game losing streak.




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TSMC Collaborates with Ansys and Microsoft to Accelerate Photonic Simulations

PITTSBURGH, Sept. 24, 2024 — Ansys and TSMC today announced a successful pilot with Microsoft that significantly speeds-up the simulation and analysis of silicon photonic components. Together, the companies achieved […]

The post TSMC Collaborates with Ansys and Microsoft to Accelerate Photonic Simulations appeared first on HPCwire.




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Alphawave Semi and TSMC Collaborate on 3nm UCIe Die-to-Die Subsystem for AI and HPC

LONDON and TORONTO, Sept. 30, 2024 — Alphawave Semi, a global leader in high-speed connectivity and compute silicon for the world’s technology infrastructure, has unveiled the availability of the industry’s […]

The post Alphawave Semi and TSMC Collaborate on 3nm UCIe Die-to-Die Subsystem for AI and HPC appeared first on HPCwire.




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Celestial AI Acquires Rockley Photonics Patent Portfolio, Strengthening Photonic Fabric IP

SANTA CLARA, Calif., Oct. 22, 2024 — Celestial AI today announced the acquisition of silicon photonics intellectual property from Rockley Photonics, including worldwide issued and pending patents. The combination of Celestial […]

The post Celestial AI Acquires Rockley Photonics Patent Portfolio, Strengthening Photonic Fabric IP appeared first on HPCwire.




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Advance Science, Technology and Sophistication with SX-Aurora TSUBASA or Vector Processor or Vector Engine (VE)

Noritaka Hoshi, Senior Manager, AI Platform Division, talks about the impetus for and challenges within the development of SX-Aurora TSUBASA or a massive SIMD, created to handle enormous computing and […]

The post Advance Science, Technology and Sophistication with SX-Aurora TSUBASA or Vector Processor or Vector Engine (VE) appeared first on HPCwire.