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SUMOylation of the transcription factor ZFHX3 at Lys-2806 requires SAE1, UBC9, and PIAS2 and enhances its stability and function in cell proliferation [Protein Synthesis and Degradation]

SUMOylation is a posttranslational modification (PTM) at a lysine residue and is crucial for the proper functions of many proteins, particularly of transcription factors, in various biological processes. Zinc finger homeobox 3 (ZFHX3), also known as AT motif-binding factor 1 (ATBF1), is a large transcription factor that is active in multiple pathological processes, including atrial fibrillation and carcinogenesis, and in circadian regulation and development. We have previously demonstrated that ZFHX3 is SUMOylated at three or more lysine residues. Here, we investigated which enzymes regulate ZFHX3 SUMOylation and whether SUMOylation modulates ZFHX3 stability and function. We found that SUMO1, SUMO2, and SUMO3 each are conjugated to ZFHX3. Multiple lysine residues in ZFHX3 were SUMOylated, but Lys-2806 was the major SUMOylation site, and we also found that it is highly conserved among ZFHX3 orthologs from different animal species. Using molecular analyses, we identified the enzymes that mediate ZFHX3 SUMOylation; these included SUMO1-activating enzyme subunit 1 (SAE1), an E1-activating enzyme; SUMO-conjugating enzyme UBC9 (UBC9), an E2-conjugating enzyme; and protein inhibitor of activated STAT2 (PIAS2), an E3 ligase. Multiple analyses established that both SUMO-specific peptidase 1 (SENP1) and SENP2 deSUMOylate ZFHX3. SUMOylation at Lys-2806 enhanced ZFHX3 stability by interfering with its ubiquitination and proteasomal degradation. Functionally, Lys-2806 SUMOylation enabled ZFHX3-mediated cell proliferation and xenograft tumor growth of the MDA-MB-231 breast cancer cell line. These findings reveal the enzymes involved in, and the functional consequences of, ZFHX3 SUMOylation, insights that may help shed light on ZFHX3's roles in various cellular and pathophysiological processes.




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Polarization of protease-activated receptor 2 (PAR-2) signaling is altered during airway epithelial remodeling and deciliation [Immunology]

Protease-activated receptor 2 (PAR-2) is activated by secreted proteases from immune cells or fungi. PAR-2 is normally expressed basolaterally in differentiated nasal ciliated cells. We hypothesized that epithelial remodeling during diseases characterized by cilial loss and squamous metaplasia may alter PAR-2 polarization. Here, using a fluorescent arrestin assay, we confirmed that the common fungal airway pathogen Aspergillus fumigatus activates heterologously-expressed PAR-2. Endogenous PAR-2 activation in submerged airway RPMI 2650 or NCI–H520 squamous cells increased intracellular calcium levels and granulocyte macrophage–colony-stimulating factor, tumor necrosis factor α, and interleukin (IL)-6 secretion. RPMI 2650 cells cultured at an air–liquid interface (ALI) responded to apically or basolaterally applied PAR-2 agonists. However, well-differentiated primary nasal epithelial ALIs responded only to basolateral PAR-2 stimulation, indicated by calcium elevation, increased cilia beat frequency, and increased fluid and cytokine secretion. We exposed primary cells to disease-related modifiers that alter epithelial morphology, including IL-13, cigarette smoke condensate, and retinoic acid deficiency, at concentrations and times that altered epithelial morphology without causing breakdown of the epithelial barrier to model early disease states. These altered primary cultures responded to both apical and basolateral PAR-2 stimulation. Imaging nasal polyps and control middle turbinate explants, we found that nasal polyps, but not turbinates, exhibit apical calcium responses to PAR-2 stimulation. However, isolated ciliated cells from both polyps and turbinates maintained basolateral PAR-2 polarization, suggesting that the calcium responses originated from nonciliated cells. Altered PAR-2 polarization in disease-remodeled epithelia may enhance apical responses and increase sensitivity to inhaled proteases.




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A flexible network of vimentin intermediate filaments promotes migration of amoeboid cancer cells through confined environments [Cell Biology]

Tumor cells can spread to distant sites through their ability to switch between mesenchymal and amoeboid (bleb-based) migration. Because of this difference, inhibitors of metastasis must account for each migration mode. However, the role of vimentin in amoeboid migration has not been determined. Because amoeboid leader bleb–based migration (LBBM) occurs in confined spaces and vimentin is known to strongly influence cell-mechanical properties, we hypothesized that a flexible vimentin network is required for fast amoeboid migration. To this end, here we determined the precise role of the vimentin intermediate filament system in regulating the migration of amoeboid human cancer cells. Vimentin is a classic marker of epithelial-to-mesenchymal transition and is therefore an ideal target for a metastasis inhibitor. Using a previously developed polydimethylsiloxane slab–based approach to confine cells, RNAi-based vimentin silencing, vimentin overexpression, pharmacological treatments, and measurements of cell stiffness, we found that RNAi-mediated depletion of vimentin increases LBBM by ∼50% compared with control cells and that vimentin overexpression and simvastatin-induced vimentin bundling inhibit fast amoeboid migration and proliferation. Importantly, these effects were independent of changes in actomyosin contractility. Our results indicate that a flexible vimentin intermediate filament network promotes LBBM of amoeboid cancer cells in confined environments and that vimentin bundling perturbs cell-mechanical properties and inhibits the invasive properties of cancer cells.




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ADAM10 and ADAM17 proteases mediate proinflammatory cytokine-induced and constitutive cleavage of endomucin from the endothelial surface [Membrane Biology]

Contact between inflammatory cells and endothelial cells (ECs) is a crucial step in vascular inflammation. Recently, we demonstrated that the cell-surface level of endomucin (EMCN), a heavily O-glycosylated single-transmembrane sialomucin, interferes with the interactions between inflammatory cells and ECs. We have also shown that, in response to an inflammatory stimulus, EMCN is cleared from the cell surface by an unknown mechanism. In this study, using adenovirus-mediated overexpression of a tagged EMCN in human umbilical vein ECs, we found that treatment with tumor necrosis factor α (TNF-α) or the strong oxidant pervanadate leads to loss of cell-surface EMCN and increases the levels of the C-terminal fragment of EMCN 3- to 4-fold. Furthermore, treatment with the broad-spectrum matrix metalloproteinase inhibitor batimastat (BB94) or inhibition of ADAM metallopeptidase domain 10 (ADAM10) and ADAM17 with two small-molecule inhibitors, GW280264X and GI254023X, or with siRNA significantly reduced basal and TNFα-induced cell-surface EMCN cleavage. Release of the C-terminal fragment of EMCN by TNF-α treatment was blocked by chemical inhibition of ADAM10 alone or in combination with ADAM17. These results indicate that cell-surface EMCN undergoes constitutive cleavage and that TNF-α treatment dramatically increases this cleavage, which is mediated predominantly by ADAM10 and ADAM17. As endothelial cell-surface EMCN attenuates leukocyte–EC interactions during inflammation, we propose that EMCN is a potential therapeutic target to manage vascular inflammation.




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The tethering function of mitofusin2 controls osteoclast differentiation by modulating the Ca2+-NFATc1 axis [A2;A22]

Dynamic regulation of the mitochondrial network by mitofusins (MFNs) modulates energy production, cell survival, and many intracellular signaling events, including calcium handling. However, the relative importance of specific mitochondrial functions and their dependence on MFNs vary greatly among cell types. Osteoclasts have many mitochondria, and increased mitochondrial biogenesis and oxidative phosphorylation enhance bone resorption, but little is known about the mitochondrial network or MFNs in osteoclasts. Because expression of each MFN isoform increases with osteoclastogenesis, we conditionally deleted MFN1 and MFN2 (double conditional KO (dcKO)) in murine osteoclast precursors, finding that this increased bone mass in young female mice and abolished osteoclast precursor differentiation into mature osteoclasts in vitro. Defective osteoclastogenesis was reversed by overexpression of MFN2 but not MFN1; therefore, we generated mice lacking only MFN2 in osteoclasts. MFN2-deficient female mice had increased bone mass at 1 year and resistance to Receptor Activator of NF-κB Ligand (RANKL)-induced osteolysis at 8 weeks. To explore whether MFN-mediated tethering or mitophagy is important for osteoclastogenesis, we overexpressed MFN2 variants defective in either function in dcKO precursors and found that, although mitophagy was dispensable for differentiation, tethering was required. Because the master osteoclastogenic transcriptional regulator nuclear factor of activated T cells 1 (NFATc1) is calcium-regulated, we assessed calcium release from the endoplasmic reticulum and store-operated calcium entry and found that the latter was blunted in dcKO cells. Restored osteoclast differentiation by expression of intact MFN2 or the mitophagy-defective variant was associated with normalization of store-operated calcium entry and NFATc1 levels, indicating that MFN2 controls mitochondrion–endoplasmic reticulum tethering in osteoclasts.




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A kinesin adapter directly mediates dendritic mRNA localization during neural development in mice [Neurobiology]

Motor protein-based active transport is essential for mRNA localization and local translation in animal cells, yet how mRNA granules interact with motor proteins remains poorly understood. Using an unbiased yeast two–hybrid screen for interactions between murine RNA-binding proteins (RBPs) and motor proteins, here we identified protein interaction with APP tail-1 (PAT1) as a potential direct adapter between zipcode-binding protein 1 (ZBP1, a β-actin RBP) and the kinesin-I motor complex. The amino acid sequence of mouse PAT1 is similar to that of the kinesin light chain (KLC), and we found that PAT1 binds to KLC directly. Studying PAT1 in mouse primary hippocampal neuronal cultures from both sexes and using structured illumination microscopic imaging of these neurons, we observed that brain-derived neurotrophic factor (BDNF) enhances co-localization of dendritic ZBP1 and PAT1 within granules that also contain kinesin-I. PAT1 is essential for BDNF-stimulated neuronal growth cone development and dendritic protrusion formation, and we noted that ZBP1 and PAT1 co-locate along with β-actin mRNA in actively transported granules in living neurons. Acute disruption of the PAT1–ZBP1 interaction in neurons with PAT1 siRNA or a dominant-negative ZBP1 construct diminished localization of β-actin mRNA but not of Ca2+/calmodulin-dependent protein kinase IIα (CaMKIIα) mRNA in dendrites. The aberrant β-actin mRNA localization resulted in abnormal dendritic protrusions and growth cone dynamics. These results suggest a critical role for PAT1 in BDNF-induced β-actin mRNA transport during postnatal development and reveal a new molecular mechanism for mRNA localization in vertebrates.




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Crystallographic and kinetic analyses of the FdsBG subcomplex of the cytosolic formate dehydrogenase FdsABG from Cupriavidus necator [Molecular Biophysics]

Formate oxidation to carbon dioxide is a key reaction in one-carbon compound metabolism, and its reverse reaction represents the first step in carbon assimilation in the acetogenic and methanogenic branches of many anaerobic organisms. The molybdenum-containing dehydrogenase FdsABG is a soluble NAD+-dependent formate dehydrogenase and a member of the NADH dehydrogenase superfamily. Here, we present the first structure of the FdsBG subcomplex of the cytosolic FdsABG formate dehydrogenase from the hydrogen-oxidizing bacterium Cupriavidus necator H16 both with and without bound NADH. The structures revealed that the two iron-sulfur clusters, Fe4S4 in FdsB and Fe2S2 in FdsG, are closer to the FMN than they are in other NADH dehydrogenases. Rapid kinetic studies and EPR measurements of rapid freeze-quenched samples of the NADH reduction of FdsBG identified a neutral flavin semiquinone, FMNH•, not previously observed to participate in NADH-mediated reduction of the FdsABG holoenzyme. We found that this semiquinone forms through the transfer of one electron from the fully reduced FMNH−, initially formed via NADH-mediated reduction, to the Fe2S2 cluster. This Fe2S2 cluster is not part of the on-path chain of iron-sulfur clusters connecting the FMN of FdsB with the active-site molybdenum center of FdsA. According to the NADH-bound structure, the nicotinamide ring stacks onto the re-face of the FMN. However, NADH binding significantly reduced the electron density for the isoalloxazine ring of FMN and induced a conformational change in residues of the FMN-binding pocket that display peptide-bond flipping upon NAD+ binding in proper NADH dehydrogenases.




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The histone H4 basic patch regulates SAGA-mediated H2B deubiquitination and histone acetylation [DNA and Chromosomes]

Histone H2B monoubiquitylation (H2Bub1) has central functions in multiple DNA-templated processes, including gene transcription, DNA repair, and replication. H2Bub1 also is required for the trans-histone regulation of H3K4 and H3K79 methylation. Although previous studies have elucidated the basic mechanisms that establish and remove H2Bub1, we have only an incomplete understanding of how H2Bub1 is regulated. We report here that the histone H4 basic patch regulates H2Bub1. Yeast cells with arginine-to-alanine mutations in the H4 basic patch (H42RA) exhibited a significant loss of global H2Bub1. H42RA mutant yeast strains also displayed chemotoxin sensitivities similar to, but less severe than, strains containing a complete loss of H2Bub1. We found that the H4 basic patch regulates H2Bub1 levels independently of interactions with chromatin remodelers and separately from its regulation of H3K79 methylation. To measure H2B ubiquitylation and deubiquitination kinetics in vivo, we used a rapid and reversible optogenetic tool, the light-inducible nuclear exporter, to control the subcellular location of the H2Bub1 E3 ligase, Bre1. The ability of Bre1 to ubiquitylate H2B was unaffected in the H42RA mutant. In contrast, H2Bub1 deubiquitination by SAGA-associated Ubp8, but not by Ubp10, increased in the H42RA mutant. Consistent with a function for the H4 basic patch in regulating SAGA deubiquitinase activity, we also detected increased SAGA-mediated histone acetylation in H4 basic patch mutants. Our findings uncover that the H4 basic patch has a regulatory function in SAGA-mediated histone modifications.




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The short variant of optic atrophy 1 (OPA1) improves cell survival under oxidative stress [Bioenergetics]

Optic atrophy 1 (OPA1) is a dynamin protein that mediates mitochondrial fusion at the inner membrane. OPA1 is also necessary for maintaining the cristae and thus essential for supporting cellular energetics. OPA1 exists as membrane-anchored long form (L-OPA1) and short form (S-OPA1) that lacks the transmembrane region and is generated by cleavage of L-OPA1. Mitochondrial dysfunction and cellular stresses activate the inner membrane–associated zinc metallopeptidase OMA1 that cleaves L-OPA1, causing S-OPA1 accumulation. The prevailing notion has been that L-OPA1 is the functional form, whereas S-OPA1 is an inactive cleavage product in mammals, and that stress-induced OPA1 cleavage causes mitochondrial fragmentation and sensitizes cells to death. However, S-OPA1 contains all functional domains of dynamin proteins, suggesting that it has a physiological role. Indeed, we recently demonstrated that S-OPA1 can maintain cristae and energetics through its GTPase activity, despite lacking fusion activity. Here, applying oxidant insult that induces OPA1 cleavage, we show that cells unable to generate S-OPA1 are more sensitive to this stress under obligatory respiratory conditions, leading to necrotic death. These findings indicate that L-OPA1 and S-OPA1 differ in maintaining mitochondrial function. Mechanistically, we found that cells that exclusively express L-OPA1 generate more superoxide and are more sensitive to Ca2+-induced mitochondrial permeability transition, suggesting that S-OPA1, and not L-OPA1, protects against cellular stress. Importantly, silencing of OMA1 expression increased oxidant-induced cell death, indicating that stress-induced OPA1 cleavage supports cell survival. Our findings suggest that S-OPA1 generation by OPA1 cleavage is a survival mechanism in stressed cells.




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Small-molecule agonists of the RET receptor tyrosine kinase activate biased trophic signals that are influenced by the presence of GFRa1 co-receptors [Neurobiology]

Glial cell line–derived neurotrophic factor (GDNF) is a growth factor that regulates the health and function of neurons and other cells. GDNF binds to GDNF family receptor α1 (GFRa1), and the resulting complex activates the RET receptor tyrosine kinase and subsequent downstream signals. This feature restricts GDNF activity to systems in which GFRa1 and RET are both present, a scenario that may constrain GDNF breadth of action. Furthermore, this co-dependence precludes the use of GDNF as a tool to study a putative functional cross-talk between GFRa1 and RET. Here, using biochemical techniques, terminal deoxynucleotidyl transferase dUTP nick end labeling staining, and immunohistochemistry in murine cells, tissues, or retinal organotypic cultures, we report that a naphthoquinone/quinolinedione family of small molecules (Q compounds) acts as RET agonists. We found that, like GDNF, signaling through the parental compound Q121 is GFRa1-dependent. Structural modifications of Q121 generated analogs that activated RET irrespective of GFRa1 expression. We used these analogs to examine RET–GFRa1 interactions and show that GFRa1 can influence RET-mediated signaling and enhance or diminish AKT Ser/Thr kinase or extracellular signal-regulated kinase signaling in a biased manner. In a genetic mutant model of retinitis pigmentosa, a lead compound, Q525, afforded sustained RET activation and prevented photoreceptor neuron loss in the retina. This work uncovers key components of the dynamic relationships between RET and its GFRa co-receptor and provides RET agonist scaffolds for drug development.




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Non-photopic and photopic visual cycles differentially regulate immediate, early, and late phases of cone photoreceptor-mediated vision [Molecular Bases of Disease]

Cone photoreceptors in the retina enable vision over a wide range of light intensities. However, the processes enabling cone vision in bright light (i.e. photopic vision) are not adequately understood. Chromophore regeneration of cone photopigments may require the retinal pigment epithelium (RPE) and/or retinal Müller glia. In the RPE, isomerization of all-trans-retinyl esters to 11-cis-retinol is mediated by the retinoid isomerohydrolase Rpe65. A putative alternative retinoid isomerase, dihydroceramide desaturase-1 (DES1), is expressed in RPE and Müller cells. The retinol-isomerase activities of Rpe65 and Des1 are inhibited by emixustat and fenretinide, respectively. Here, we tested the effects of these visual cycle inhibitors on immediate, early, and late phases of cone photopic vision. In zebrafish larvae raised under cyclic light conditions, fenretinide impaired late cone photopic vision, while the emixustat-treated zebrafish unexpectedly had normal vision. In contrast, emixustat-treated larvae raised under extensive dark-adaptation displayed significantly attenuated immediate photopic vision concomitant with significantly reduced 11-cis-retinaldehyde (11cRAL). Following 30 min of light, early photopic vision was recovered, despite 11cRAL levels remaining significantly reduced. Defects in immediate cone photopic vision were rescued in emixustat- or fenretinide-treated larvae following exogenous 9-cis-retinaldehyde supplementation. Genetic knockout of Des1 (degs1) or retinaldehyde-binding protein 1b (rlbp1b) did not eliminate photopic vision in zebrafish. Our findings define molecular and temporal requirements of the nonphotopic or photopic visual cycles for mediating vision in bright light.




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Inhibition of glycosphingolipid biosynthesis reverts multidrug resistance by differentially modulating ABC transporters in chronic myeloid leukemias [Cell Biology]

Multidrug resistance (MDR) in cancer arises from cross-resistance to structurally- and functionally-divergent chemotherapeutic drugs. In particular, MDR is characterized by increased expression and activity of ATP-binding cassette (ABC) superfamily transporters. Sphingolipids are substrates of ABC proteins in cell signaling, membrane biosynthesis, and inflammation, for example, and their products can favor cancer progression. Glucosylceramide (GlcCer) is a ubiquitous glycosphingolipid (GSL) generated by glucosylceramide synthase, a key regulatory enzyme encoded by the UDP-glucose ceramide glucosyltransferase (UGCG) gene. Stressed cells increase de novo biosynthesis of ceramides, which return to sub-toxic levels after UGCG mediates incorporation into GlcCer. Given that cancer cells seem to mobilize UGCG and have increased GSL content for ceramide clearance, which ultimately contributes to chemotherapy failure, here we investigated how inhibition of GSL biosynthesis affects the MDR phenotype of chronic myeloid leukemias. We found that MDR is associated with higher UGCG expression and with a complex GSL profile. UGCG inhibition with the ceramide analog d-threo-1-(3,4,-ethylenedioxy)phenyl-2-palmitoylamino-3-pyrrolidino-1-propanol (EtDO-P4) greatly reduced GSL and monosialotetrahexosylganglioside levels, and co-treatment with standard chemotherapeutics sensitized cells to mitochondrial membrane potential loss and apoptosis. ABC subfamily B member 1 (ABCB1) expression was reduced, and ABCC-mediated efflux activity was modulated by competition with nonglycosylated ceramides. Consistently, inhibition of ABCC-mediated transport reduced the efflux of exogenous C6-ceramide. Overall, UGCG inhibition impaired the malignant glycophenotype of MDR leukemias, which typically overcomes drug resistance through distinct mechanisms. This work sheds light on the involvement of GSL in chemotherapy failure, and its findings suggest that targeted GSL modulation could help manage MDR leukemias.




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Inflammatory and mitogenic signals drive interleukin 23 subunit alpha (IL23A) secretion independent of IL12B in intestinal epithelial cells [Signal Transduction]

The heterodimeric cytokine interleukin-23 (IL-23 or IL23A/IL12B) is produced by dendritic cells and macrophages and promotes the proinflammatory and regenerative activities of T helper 17 (Th17) and innate lymphoid cells. A recent study has reported that IL-23 is also secreted by lung adenoma cells and generates an inflammatory and immune-suppressed stroma. Here, we observed that proinflammatory tumor necrosis factor (TNF)/NF-κB and mitogen-activated protein kinase (MAPK) signaling strongly induce IL23A expression in intestinal epithelial cells. Moreover, we identified a strong crosstalk between the NF-κB and MAPK/ERK kinase (MEK) pathways, involving the formation of a transcriptional enhancer complex consisting of proto-oncogene c-Jun (c-Jun), RELA proto-oncogene NF-κB subunit (RelA), RUNX family transcription factor 1 (RUNX1), and RUNX3. Collectively, these proteins induced IL23A secretion, confirmed by immunoprecipitation of endogenous IL23A from activated human colorectal cancer (CRC) cell culture supernatants. Interestingly, IL23A was likely secreted in a noncanonical form, as it was not detected by an ELISA specific for heterodimeric IL-23 likely because IL12B expression is absent in CRC cells. Given recent evidence that IL23A promotes tumor formation, we evaluated the efficacy of MAPK/NF-κB inhibitors in attenuating IL23A expression and found that the MEK inhibitor trametinib and BAY 11–7082 (an IKKα/IκB inhibitor) effectively inhibited IL23A in a subset of human CRC lines with mutant KRAS or BRAFV600E mutations. Together, these results indicate that proinflammatory and mitogenic signals dynamically regulate IL23A in epithelial cells. They further reveal its secretion in a noncanonical form independent of IL12B and that small-molecule inhibitors can attenuate IL23A secretion.




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RNA helicase-regulated processing of the Synechocystis rimO-crhR operon results in differential cistron expression and accumulation of two sRNAs [Gene Regulation]

The arrangement of functionally-related genes in operons is a fundamental element of how genetic information is organized in prokaryotes. This organization ensures coordinated gene expression by co-transcription. Often, however, alternative genetic responses to specific stress conditions demand the discoordination of operon expression. During cold temperature stress, accumulation of the gene encoding the sole Asp–Glu–Ala–Asp (DEAD)-box RNA helicase in Synechocystis sp. PCC 6803, crhR (slr0083), increases 15-fold. Here, we show that crhR is expressed from a dicistronic operon with the methylthiotransferase rimO/miaB (slr0082) gene, followed by rapid processing of the operon transcript into two monocistronic mRNAs. This cleavage event is required for and results in destabilization of the rimO transcript. Results from secondary structure modeling and analysis of RNase E cleavage of the rimO–crhR transcript in vitro suggested that CrhR plays a role in enhancing the rate of the processing in an auto-regulatory manner. Moreover, two putative small RNAs are generated from additional processing, degradation, or both of the rimO transcript. These results suggest a role for the bacterial RNA helicase CrhR in RNase E-dependent mRNA processing in Synechocystis and expand the known range of organisms possessing small RNAs derived from processing of mRNA transcripts.




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A neuroglobin-based high-affinity ligand trap reverses carbon monoxide-induced mitochondrial poisoning [Molecular Biophysics]

Carbon monoxide (CO) remains the most common cause of human poisoning. The consequences of CO poisoning include cardiac dysfunction, brain injury, and death. CO causes toxicity by binding to hemoglobin and by inhibiting mitochondrial cytochrome c oxidase (CcO), thereby decreasing oxygen delivery and inhibiting oxidative phosphorylation. We have recently developed a CO antidote based on human neuroglobin (Ngb-H64Q-CCC). This molecule enhances clearance of CO from red blood cells in vitro and in vivo. Herein, we tested whether Ngb-H64Q-CCC can also scavenge CO from CcO and attenuate CO-induced inhibition of mitochondrial respiration. Heart tissue from mice exposed to 3% CO exhibited a 42 ± 19% reduction in tissue respiration rate and a 33 ± 38% reduction in CcO activity compared with unexposed mice. Intravenous infusion of Ngb-H64Q-CCC restored respiration rates to that of control mice correlating with higher electron transport chain CcO activity in Ngb-H64Q-CCC–treated compared with PBS-treated, CO-poisoned mice. Further, using a Clark-type oxygen electrode, we measured isolated rat liver mitochondrial respiration in the presence and absence of saturating solutions of CO (160 μm) and nitric oxide (100 μm). Both CO and NO inhibited respiration, and treatment with Ngb-H64Q-CCC (100 and 50 μm, respectively) significantly reversed this inhibition. These results suggest that Ngb-H64Q-CCC mitigates CO toxicity by scavenging CO from carboxyhemoglobin, improving systemic oxygen delivery and reversing the inhibitory effects of CO on mitochondria. We conclude that Ngb-H64Q-CCC or other CO scavengers demonstrate potential as antidotes that reverse the clinical and molecular effects of CO poisoning.




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Endorepellin evokes an angiostatic stress signaling cascade in endothelial cells [Glycobiology and Extracellular Matrices]

Endorepellin, the C-terminal fragment of the heparan sulfate proteoglycan perlecan, influences various signaling pathways in endothelial cells by binding to VEGFR2. In this study, we discovered that soluble endorepellin activates the canonical stress signaling pathway consisting of PERK, eIF2α, ATF4, and GADD45α. Specifically, endorepellin evoked transient activation of VEGFR2, which, in turn, phosphorylated PERK at Thr980. Subsequently, PERK phosphorylated eIF2α at Ser51, upregulating its downstream effector proteins ATF4 and GADD45α. RNAi-mediated knockdown of PERK or eIF2α abrogated the endorepellin-mediated up-regulation of GADD45α, the ultimate effector protein of this stress signaling cascade. To functionally validate these findings, we utilized an ex vivo model of angiogenesis. Exposure of the aortic rings embedded in 3D fibrillar collagen to recombinant endorepellin for 2–4 h activated PERK and induced GADD45α vis à vis vehicle-treated counterparts. Similar effects were obtained with the established cellular stress inducer tunicamycin. Notably, chronic exposure of aortic rings to endorepellin for 7–9 days markedly suppressed vessel sprouting, an angiostatic effect that was rescued by blocking PERK kinase activity. Our findings unravel a mechanism by which an extracellular matrix protein evokes stress signaling in endothelial cells, which leads to angiostasis.




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Brain manganese and the balance between essential roles and neurotoxicity [Molecular Bases of Disease]

Manganese (Mn) is an essential micronutrient required for the normal development of many organs, including the brain. Although its roles as a cofactor in several enzymes and in maintaining optimal physiology are well-known, the overall biological functions of Mn are rather poorly understood. Alterations in body Mn status are associated with altered neuronal physiology and cognition in humans, and either overexposure or (more rarely) insufficiency can cause neurological dysfunction. The resultant balancing act can be viewed as a hormetic U-shaped relationship for biological Mn status and optimal brain health, with changes in the brain leading to physiological effects throughout the body and vice versa. This review discusses Mn homeostasis, biomarkers, molecular mechanisms of cellular transport, and neuropathological changes associated with disruptions of Mn homeostasis, especially in its excess, and identifies gaps in our understanding of the molecular and biochemical mechanisms underlying Mn homeostasis and neurotoxicity.




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The testis-specific LINC component SUN3 is essential for sperm head shaping during mouse spermiogenesis [Cell Biology]

Sperm head shaping is a key event in spermiogenesis and is tightly controlled via the acrosome–manchette network. Linker of nucleoskeleton and cytoskeleton (LINC) complexes consist of Sad1 and UNC84 domain–containing (SUN) and Klarsicht/ANC-1/Syne-1 homology (KASH) domain proteins and form conserved nuclear envelope bridges implicated in transducing mechanical forces from the manchette to sculpt sperm nuclei into a hook-like shape. However, the role of LINC complexes in sperm head shaping is still poorly understood. Here we assessed the role of SUN3, a testis-specific LINC component harboring a conserved SUN domain, in spermiogenesis. We show that CRISPR/Cas9-generated Sun3 knockout male mice are infertile, displaying drastically reduced sperm counts and a globozoospermia-like phenotype, including a missing, mislocalized, or fragmented acrosome, as well as multiple defects in sperm flagella. Further examination revealed that the sperm head abnormalities are apparent at step 9 and that the sperm nuclei fail to elongate because of the absence of manchette microtubules and perinuclear rings. These observations indicate that Sun3 deletion likely impairs the ability of the LINC complex to transduce the cytoskeletal force to the nuclear envelope, required for sperm head elongation. We also found that SUN3 interacts with SUN4 in mouse testes and that the level of SUN4 proteins is drastically reduced in Sun3-null mice. Altogether, our results indicate that SUN3 is essential for sperm head shaping and male fertility, providing molecular clues regarding the underlying pathology of the globozoospermia-like phenotype.




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A single amino acid substitution uncouples catalysis and allostery in an essential biosynthetic enzyme in Mycobacterium tuberculosis [Enzymology]

Allostery exploits the conformational dynamics of enzymes by triggering a shift in population ensembles toward functionally distinct conformational or dynamic states. Allostery extensively regulates the activities of key enzymes within biosynthetic pathways to meet metabolic demand for their end products. Here, we have examined a critical enzyme, 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase (DAH7PS), at the gateway to aromatic amino acid biosynthesis in Mycobacterium tuberculosis, which shows extremely complex dynamic allostery: three distinct aromatic amino acids jointly communicate occupancy to the active site via subtle changes in dynamics, enabling exquisite fine-tuning of delivery of these essential metabolites. Furthermore, this allosteric mechanism is co-opted by pathway branchpoint enzyme chorismate mutase upon complex formation. In this study, using statistical coupling analysis, site-directed mutagenesis, isothermal calorimetry, small-angle X-ray scattering, and X-ray crystallography analyses, we have pinpointed a critical node within the complex dynamic communication network responsible for this sophisticated allosteric machinery. Through a facile Gly to Pro substitution, we have altered backbone dynamics, completely severing the allosteric signal yet remarkably, generating a nonallosteric enzyme that retains full catalytic activity. We also identified a second residue of prime importance to the inter-enzyme communication with chorismate mutase. Our results reveal that highly complex dynamic allostery is surprisingly vulnerable and provide further insights into the intimate link between catalysis and allostery.




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Infant of a Diabetic Mother With an Anomaly




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Case 2: Mysterious Hyperkalemia in a Premature Infant of 25 Weeks Gestation




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Pathogenesis and Management of Indirect Hyperbilirubinemia in Preterm Neonates Less Than 35 Weeks: Moving Toward a Standardized Approach

Premature infants have a higher incidence of indirect hyperbilirubinemia than term infants. Management of neonatal indirect hyperbilirubinemia in late preterm and term neonates has been well addressed by recognized, consensus-based guidelines. However, the extension of these guidelines to the preterm population has been an area of uncertainty because of limited evidence. This leads to variation in clinical practice and lack of recognition of the spectrum of bilirubin-induced neurologic dysfunction (BIND) in this population. Preterm infants are metabolically immature and at higher risk for BIND at lower bilirubin levels than their term counterparts. Early use of phototherapy to eliminate BIND and minimize the need for exchange transfusion is the goal of treatment in premature neonates. Although considered relatively safe, phototherapy does have side effects, and some NICUs tend to overuse phototherapy. In this review, we describe the epidemiology and pathophysiology of BIND in preterm neonates, and discuss our approach to standardized management of indirect hyperbilirubinemia in the vulnerable preterm population. The proposed treatment charts suggest early use of phototherapy in preterm neonates with the aim of reducing exposure to high irradiance levels, minimizing the need for exchange transfusions, and preventing BIND. The charts are pragmatic and have additional curves for stopping phototherapy and escalating its intensity. Having a standardized approach would support future research and quality improvement initiatives that examine dose and duration of phototherapy exposure with relation to outcomes.




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Seismic pore pressure prediction at the Halten Terrace in the Norwegian Sea

Pre-drill pore pressure prediction is essential for safe and efficient drilling, and is a key element in the risk-reducing toolbox when designing a well. On the Norwegian Continental Shelf, pore pressure prediction commonly relies on traditional 1D offset well analysis, whereas velocity data from seismic surveys are often not considered. Our work with seismic interval velocities shows that the velocity field can provide an important basis for pressure prediction and enable the construction of regional 3D pressure cubes. This may increase the confidence in the pore pressure models and aid the pre-drill geohazard screening process. We demonstrate how a 3D velocity field can be converted to a 3D pore pressure cube using reported pressures in offset wells as calibration points. The method is applied to a regional dataset at the Halten Terrace in the Norwegian Sea; an area with a complex pattern of pore pressure anomalies which traditionally has been difficult to predict. The algorithm is searching for a velocity to pore pressure transform that best matches the reported pressures. The 3D velocity field is a proxy of rock velocity and is derived from seismic surveys, and is verified to checkshot velocities and sonic data in the offset wells.




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Cyclical variations of fluid sources and stress state in a shallow megathrust-zone melange

Differences in REE patterns of calcite from extensional and shear veins of the Sestola Vidiciatico Tectonic Unit in the Northern Apennines suggest variations in fluid source during the seismic cycle in an ancient analogue of a shallow megathrust (Tmax c. 100–150°C). In shear veins, a positive Eu anomaly suggests an exotic fluid source, probably hotter than the fault environment. Small-scale extensional veins were derived instead from a local fluid in equilibrium with the fault rocks. Mutually crosscutting relations between two extensional vein sets, parallel and perpendicular to the megathrust, suggest repeated shifting of the 1 and 3 stresses during the seismic cycle. This is consistent with: (1) a seismic phase, with brittle failure along the thrust, crystallization of shear veins from an exotic fluid, stress drop and stress rotation; (2) a post-seismic phase, with fault-normal compaction and formation of fault-normal extensional veins fed by local fluids; (3) a reloading phase, where shear stress and pore pressure are gradually restored and fault-parallel extensional veins form, until the thrust fails again. The combination of geochemical and structural analyses in veins from exhumed megathrust analogues represents a promising tool to better understand the interplay between stress state and fluids in modern subduction zones.

Supplementary material: Cathodoluminescence microphotographs, methodological details of the microstructural analysis, microphotographs of the location of analysed spots and a geochemical data table are available at https://doi.org/10.6084/m9.figshare.c.4842165

Thematic collection: This article is part of the Polygenetic mélanges collection available at: https://www.lyellcollection.org/cc/polygenetic-melanges




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The progressive development of microfabrics from initial deposition to slump deformation: an example from a modern sedimenary melange on the Nankai Prism

The progressive development of microfabrics from initial deposition to slump deformation and then a submarine slide was investigated in an active subduction zone using cores recovered during the Integrated Ocean Drilling Program Expedition 333. A Pleistocene–Holocene sequence was recovered at Site C0018A, which was located on a slope basin on the footwall of the megasplay fault in the Nankai Trough, SW Japan. Six mass-transport deposit units intercalated with coherent intervals were recovered from the upper 190 m of the drilled succession. The initial microfabrics in the undeformed hemipelagic sediments were characterized by random and porous fabrics composed predominantly of clay aggregations and connectors. The initial fabrics were cardhouse fabrics, which consist of clay flakes with edge-to-edge (E–E) and/or edge-to-face (E–F) contacts. These initial microfabrics developed into compacted microfabrics, which are random and consolidated fabrics (bookhouse fabrics) that consist of clay flakes with E–F and/or face-to-face (F–F) contacts and develop during burial as a pure shear deformation. During slumping, these fabrics were then deformed under simple shear to become predominantly F–F contacts and form clay chains. Thus, the microfabrics in these submarine slides are a sedimentary mélange that developed locally into a preferred clay orientation with F–F contacts.

Supplementary material: A schematic illustration showing sedimentation processes and fabrics is available at https://doi.org/10.6084/m9.figshare.c.4483385

Thematic collection: This article is part of the Polygenetic mélanges collection available at: https://www.lyellcollection.org/cc/polygenetic-melanges




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Sedimentary and diapiric melanges in the Skrzydlna area (Outer Carpathians of Poland) as indicators of basinal and structural evolution

The Dukla Nappe in the Skrzydlna area exposes two types of mélange reflecting two different phases of basinal and tectonic evolution of the Outer West Carpathian orogen in its Polish sector. The Oligocene-age sedimentary mélange (olistostrome) is related to growth of the accretionary wedge, whereas the Miocene-age diapiric mélange postdates the orogenic thrusting. Textural and structural features of the very coarse-grained sedimentary mélange suggest non-cohesive debris flows and high-density turbidity currents as predominant emplacement mechanisms. Growth strata, associated with progressive unconformities, and facies contrast between the underlying fine-grained unit and the overlying olistostrome reflect a considerable uplift of the source area and rotation of the adjacent part of the basin floor. The olistostrome and the overlying turbidite succession form a retrogressive sequence interpreted as a submarine canyon infill grading to a small submarine fan. The diapiric mélange, injected into the Oligocene-age succession of the Dukla Nappe, contains the Early and Late Cretaceous-age blocks and matrix derived from the underlying Silesian Nappe. The features reflecting diapiric emplacement include matrix proportion increase and block content decrease towards the mélange margins, scaly fabric and shear zones. Both mélanges, interpreted in the past as chaotic bodies, upon detailed examination reveal genesis-related subtle internal organization.




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Recycling of heterogeneous material in the subduction factory: evidence from the sedimentary melange of the Internal Ligurian Units, Italy

In the Northern Apennine (Italy), the Internal Ligurian Units consist of Middle–Late Jurassic ophiolites covered by thick sedimentary deposits whose top is represented by the Early Paleocene Bocco Shale. This formation is characterized by mass-transport deposits interlayered with thin-bedded siliciclastic turbidites. The sedimentological and structural features of these mass-transport deposits reveal a long-lived history of recycling of heterogeneous material in a subduction setting. This history started with the frontal accretion of a fragment of oceanic crust into an accretionary prism whose lower slope was subsequently affected by tectonic erosion and consequent instability, leading to the production of mass-transport deposits and the transfer of material to the lower plate. These mass-transport deposits were subsequently underthrust and then again transferred to the base of the accretionary prism by coherent underplating, before their exhumation to the surface. The Bocco Shale is thus representative of a subduction setting where both accretionary and erosive events occurred, depending on changing boundary conditions. The reconstructed history for the Bocco Shale indicates that the sedimentary and gravitational processes both at the prism front and on the prism slope, possibly induced by alternating accretion and erosion events, are the most efficient mechanisms of lithological mixing and recycling in subduction margins.




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Mid-Eocene giant slope failure (sedimentary melanges) in the Ligurian accretionary wedge (NW Italy) and relationships with tectonics, global climate change and the dissociation of gas hydrates

Upper Lutetian–Bartonian sedimentary mélanges, corresponding to ancient mud-rich submarine mass transport deposits, are widely distributed over an area c. 300 km long and tens of kilometres wide along the exhumed outer part of the External Ligurian accretionary wedge in the Northern Apennines. The occurrence of methane-derived carbonate concretions (septarians) in a specific tectonostratigraphic position below these sedimentary mélanges allows us to document the relationships among a significant period of regional-scale slope failure, climate change (the Early and Mid-Eocene Optimum stages), the dissociation of gas hydrates and accretionary tectonics during the Ligurian Tectonic Phase (early–mid-Lutetian). The distribution of septarians at the core of thrust-related anticlines suggests that the dissociation of gas hydrates was triggered by accretionary tectonics rather than climate change. The different ages of slope failure emplacement and the formation of the septarians support the view that the dissociation of gas hydrates was not the most important trigger for slope failure. The latter occurred during a tectonic quiescence stage associated with a regressive depositional trend, and probably minor residual tectonic pulses, which followed the Ligurian Tectonic Phase, favouring the dynamic re-equilibrium of the External Ligurian accretionary wedge. Our findings provide useful information for a better understanding of the factors controlling giant slope failure events in modern accretionary settings, where they may cause tsunamis.




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Redefinition of the Ligurian Units at the Alps-Apennines junction (NW Italy) and their role in the evolution of the Ligurian accretionary wedge: constraints from melanges and broken formations

We document that the undifferentiated chaotic Ligurian Units of the Monferrato–Torino Hill sector (MO-TH) at the Alps–Apennines junction consist of three different units that are comparable with the Cassio, Caio and Sporno Units of the External Ligurian Units of the Northern Apennines. Their internal stratigraphy reflects the character of units deposited in an ocean–continent transition (OCT) zone between the northwestern termination of the Ligurian–Piedmont oceanic basin and the thinned passive margin of Adria microcontinent. The inherited wedge-shaped architecture of this OCT, which gradually closed toward the north in the present-day Canavese Zone, controlled the Late Cretaceous–early Eocene flysch deposition at the trench of the External Ligurian accretionary wedge during the oblique subduction. This favoured the formation of an accretionary wedge increasing in thickness and elevation toward the SE, from the MO-TH to the Emilia Northern Apennines. Our results therefore provide significant information on both the palaeogeographical reconstruction of the northwestern termination of the Ligurian–Piedmont oceanic basin and the role played by inherited along-strike variations (stratigraphy, structural architecture and morphology) of OCT zones in controlling subduction–accretionary processes.

Supplementary material: A spreadsheet with X-ray fluorescence spectrometry and inductively coupled plasma mass spectrometry whole-rock major and trace element composition of mantle peridotites, and photomicrographs of mantle peridotites are available at https://doi.org/10.6084/m9.figshare.c.4519643




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Polygenetic melanges: a glimpse on tectonic, sedimentary and diapiric recycling in convergent margins

A significant part of mélanges recognized in exhumed convergent margins around the world has been recently documented to have chiefly originated from masse transport and subsurface remobilization and disruption (i.e. mélanges, from sedimentary and mud–serpentinite diapiric processes and from in situ fluidification–disruption). Tectonic and/or sedimentary processes occurring during subsequent multiple deformational events of convergent margin evolution commonly overprint and significantly rework the primary (sedimentary or diapiric) mélange fabric, forming polygenetic mélanges. This ultimately complicates their distinction from true tectonic mélanges, masking part of the recorded tectono-sedimentary evolution of the associated convergent margin. The contributions gathered in this thematic collection explore with different approaches (from field structural and stratigraphic observations to geophysical analyses) different types of polygenetic mélange, at various scales, around the world. These studies conclude that the understanding of this type of mélange may provide crucial insights for a more detailed interpretation of the evolution of ancient and modern convergent margins, and of processes and mechanisms triggering potential natural hazards (earthquakes and tsunamis). Case studies include the Apennines in the Central Mediterranean region, the Carpathians in Central Europe and the Nankai Prism in Japan.

Thematic collection: This article is part of the ‘Polygenetic mélanges: a glimpse on tectonic sedimentary and diapiric recycling in convergent margins’ collection available at https://www.lyellcollection.org/cc/polygenetic-melanges




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High-resolution carbon isotope stratigraphy of the Lower and Middle Ordovician succession of the Yangtze Platform, China: implications for global correlation

The Lower and Middle Ordovician of the Yangtze Platform, China, is characterized by a sedimentary succession dominated by carbonate rocks. Three sections spanning the Nantsinkuan/Lunshan, Fenhsiang, Hunghuayuan, and Dawan/Zitai formations, corresponding to the Tremadocian–Dapingian in age, have been sampled for high-resolution 13C chemostratigraphy (542 samples in total). Our new 13C data reveal five tie-points with the potential for global correlation: (1) a positive 13C excursion in the lower Nantsinkuan Formation within the Tremadocian Rossodus manitouensis Zone; (2) an excursion with two peaks roughly within the late Tremadocian Paltodusdeltifer’ Zone; (3) a positive 13C shift in the lower Hunghuayuan Formation, within the early Floian Serratognathus diversus Zone; (4) a gradual positive 13C shift in the late Floian, ranging from the uppermost S. diversus Zone to the basal Oepikodus evae Zone; (5) a minor negative shift in the lower Dawan/Zitai Formation, within the early Dapingian Baltoniodus triangularis Zone. These excursions are herein used for correlation of the Yangtze Platform strata with successions from South China, North China, the Argentine Precordillera, North America and Baltica. From a palaeogeographical perspective the Gudongkou, Xiangshuidong and Daling sections represent depositional environments along an inner to outer ramp profile. 13C data from these sections show successively heavier (higher) 13C values with increasing depositional depth. This is interpreted as due to remineralization of organic carbon within the carbonate rocks.

Supplementary material: Carbon and oxygen isotope data are available at: https://doi.org/10.6084/m9.figshare.c.4767080




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Weathering history and landscape evolution of Western Ghats (India) from 40Ar/39Ar dating of supergene K-Mn oxides

Laterites preserved on both sides of the Western Ghats Escarpment of Peninsular India have formed by long-term lateritic weathering essentially after India–Seychelles continental break-up following Deccan Traps emplacement (c. 63 myr ago). Supergene manganese ores of the Western Ghats were formed on Late Archean manganese protores. Among Mn oxides composing the ores, cryptomelane (K-rich Mn oxide) was characterized and dated by 40Ar/39Ar geochronology. Measured ages complement those previously obtained in other South Indian manganese ores from the hinterland plateau and further document three major weathering periods, c. 53–44, c. 39–22 and c. 14–10 Ma, the last being documented for the first time in India. These periods coincide with global palaeoclimatic proxies and date the lateritic weathering of three successive palaeolandscapes of the Western Ghats that evolved under slow denudation (c. 8 m Ma–1) over the last 44 myr and were mostly incised during the Neogene (<22 Ma). This indicates that the Western Ghats are a relict of a South Indian plateau preserved at the headwaters of very long east-flowing river systems and above the Western Ghats Escarpment. Topography and denudation history of this landscape do not require Neogene tilt of the Peninsula as recently proposed.

Supplementary material: Full details of field and sample description, methods and analytical data including electron probe microanalyses of cryptomelane, and isotopic analyses and degassing spectra of irradiated cryptomelane grains are available at https://doi.org/10.6084/m9.figshare.c.4726661




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Paleomagnetic and magnetic fabric data from Lower Triassic redbeds of the Central Western Carpathians: new constraints on the paleogeographic and tectonic evolution of the Carpathian region

In the Central Western Carpathians (CWC), most published paleomagnetic results from Permo-Mesozoic rocks document extensive remagnetizations and come from thin-skinned thrust units that have undergone multistage deformation. We present results from lower Triassic redbeds from the autochthonous cover overlying the basement that carry a primary magnetization. Petromagnetic results indicate that the dominant ferromagnetic carrier is hematite, while magnetic susceptibility and its anisotropy are controlled by both ferromagnetic and paramagnetic minerals. Magnetic fabrics document weak deformation related to Late Cretaceous shortening. The directions of the high unblocking temperature remanence components pass both reversal and fold tests, attesting to their primary nature. Paleomagnetic inclinations are flatter than expected from reference datasets, suggesting small latitudinal separation between the CWC and stable Europe. Paleomagnetic declinations are mostly clustered within individual mountain massifs, implying their tectonic coherence. They show only minor differences between the massifs, indicating a lack of significant vertical-axis tectonic rotations within the studied central parts of the CWC. The paleomagnetic declinations are therefore representative of the whole of the CWC in terms of regional paleogeographic interpretations, and imply moderate counterclockwise rotations (c. 26°) of the region with respect to stable Europe since the Early Triassic.




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The Legacy of CVI [Editorial]

Clinical and Vaccine Immunology (CVI) will merge with the American Society for Microbiology (ASM) open-access journal mSphere in January 2018. We commemorate this transition by exploring the history of CVI and that of its predecessor, Clinical and Diagnostic Laboratory Immunology (CDLI), and by acknowledging their contributors. Research on vaccines, clinical immunology, and clinical diagnostic immunology published through mSphere will be available without restrictions to an ever-larger audience, which will expedite progress in the field. ASM remains committed to supporting its members and the research community by facilitating the dissemination of scientific knowledge in these important areas.




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Acknowledgment of Ad Hoc Reviewers [Editorial]




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Randomized, Placebo-Controlled, Double-Blind Phase 2 Trial Comparing the Reactogenicity and Immunogenicity of a Single Standard Dose to Those of a High Dose of CVD 103-HgR Live Attenuated Oral Cholera Vaccine, with Shanchol Inactivated Oral Vaccine as an

Reactive immunization with a single-dose cholera vaccine that could rapidly (within days) protect immunologically naive individuals during virgin soil epidemics, when cholera reaches immunologically naive populations that have not experienced cholera for decades, would facilitate cholera control. One dose of attenuated Vibrio cholerae O1 classical Inaba vaccine CVD 103-HgR (Vaxchora) containing ≥2 x 108 CFU induces vibriocidal antibody seroconversion (a correlate of protection) in >90% of U.S. adults. A previous CVD 103-HgR commercial formulation required ≥2 x 109 CFU to elicit high levels of seroconversion in populations in developing countries. We compared the vibriocidal responses of Malians (individuals 18 to 45 years old) randomized to ingest a single ≥2 x 108-CFU standard dose (n = 50) or a ≥2 x 109-CFU high dose (n = 50) of PaxVax CVD 103-HgR with buffer or two doses (n = 50) of Shanchol inactivated cholera vaccine (the immunologic comparator). To maintain blinding, participants were dosed twice 2 weeks apart; CVD 103-HgR recipients ingested placebo 2 weeks before or after ingesting vaccine. Seroconversion (a ≥4-fold vibriocidal titer rise) between the baseline and 14 days after CVD 103-HgR ingestion and following the first and second doses of Shanchol were the main outcomes measured. By day 14 postvaccination, the rates of seroconversion after ingestion of a single standard dose and a high dose of CVD 103-HgR were 71.7% (33/46 participants) and 83.3% (40/48 participants), respectively. The rate of seroconversion following the first dose of Shanchol, 56.0% (28/50 participants), was significantly lower than that following the high dose of CVD 103-HgR (P = 0.003). The vibriocidal geometric mean titer (GMT) of the high dose of CVD 103-HgR exceeded the GMT of the standard dose at day 14 (214 versus 95, P = 0.045) and was ~2-fold higher than the GMT on day 7 and day 14 following the first Shanchol dose (P > 0.05). High-dose CVD 103-HgR is recommended for accelerated evaluation in developing countries to assess its efficacy and practicality in field situations. (This study has been registered at ClinicalTrials.gov under registration no. NCT02145377.)




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Development of an Extended-Specificity Multiplex Immunoassay for Detection of Streptococcus pneumoniae Serotype-Specific Antigen in Urine by Use of Human Monoclonal Antibodies [Diagnostic Laboratory Immunology]

Current pneumococcal vaccines cover the 10 to 23 most common serotypes of the 92 presently described. However, with the increased usage of pneumococcal-serotype-based vaccines, the risk of serotype replacement and an increase in disease caused by nonvaccine serotypes remains. Serotype surveillance of pneumococcal infections relies heavily on culture techniques, which are known to be insensitive, particularly in cases of noninvasive disease. Pneumococcal-serotype-specific urine assays offer an alternative method of serotyping for both invasive and noninvasive disease. However, the assays described previously cover mainly conjugate vaccine serotypes, give little information about circulating nonvaccine serotypes, and are currently available only in one or two specialist laboratories. Our laboratory has developed a Luminex-based extended-range antigen capture assay to detect pneumococcal-serotype-specific antigens in urine samples. The assay targets 24 distinct serotypes/serogroups plus the cell wall polysaccharide (CWP) and some cross-reactive serotypes. We report that the assay is capable of detecting all the targeted serotypes and the CWP at 0.1 ng/ml, while some serotypes are detected at concentrations as low as 0.3 pg/ml. The analytical serotype specificity was determined to be 98.4% using a panel of polysaccharide-negative urine specimens spiked with nonpneumococcal bacterial antigens. We also report clinical sensitivities of 96.2% and specificities of 89.9% established using a panel of urine specimens from patients diagnosed with community-acquired pneumonia or pneumococcal disease. This assay can be extended for testing other clinical samples and has the potential to greatly improve serotype-specific surveillance in the many cases of pneumococcal disease in which a culture is never obtained.




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Identification of Novel Antigens Recognized by Serum Antibodies in Bovine Tuberculosis [Diagnostic Laboratory Immunology]

Bovine tuberculosis (TB), caused by Mycobacterium bovis, remains an important zoonotic disease posing a serious threat to livestock and wildlife. The current TB tests relying on cell-mediated and humoral immune responses in cattle have performance limitations. To identify new serodiagnostic markers of bovine TB, we screened a panel of 101 recombinant proteins, including 10 polyepitope fusions, by a multiantigen print immunoassay (MAPIA) with well-characterized serum samples serially collected from cattle with experimental or naturally acquired M. bovis infection. A novel set of 12 seroreactive antigens was established. Evaluation of selected proteins in the dual-path platform (DPP) assay showed that the highest diagnostic accuracy (~95%) was achieved with a cocktail of five best-performing antigens, thus demonstrating the potential for development of an improved and more practical serodiagnostic test for bovine TB.




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GI-19007, a Novel Saccharomyces cerevisiae-Based Therapeutic Vaccine against Tuberculosis [Vaccines]

As yet, very few vaccine candidates with activity in animals against Mycobacterium tuberculosis infection have been tested as therapeutic postexposure vaccines. We recently described two pools of mycobacterial proteins with this activity, and here we describe further studies in which four of these proteins (Rv1738, Rv2032, Rv3130, and Rv3841) were generated as a fusion polypeptide and then delivered in a novel yeast-based platform (Tarmogen) which itself has immunostimulatory properties, including activation of Toll-like receptors. This platform can deliver antigens into both the class I and class II antigen presentation pathways and stimulate strong Th1 and Th17 responses. In mice this fusion vaccine, designated GI-19007, was immunogenic and elicited strong gamma interferon (IFN-) and interleukin-17 (IL-17) responses; despite this, they displayed minimal prophylactic activity in mice that were subsequently infected with a virulent clinical strain. In contrast, in a therapeutic model in the guinea pig, GI-19007 significantly reduced the lung bacterial load and reduced lung pathology, particularly in terms of secondary lesion development, while significantly improving survival in one-third of these animals. In further studies in which guinea pigs were vaccinated with BCG before challenge, therapeutic vaccination with GI-19007 initially improved survival versus that of animals given BCG alone, although this protective effect was gradually lost at around 400 days after challenge. Given its apparent ability to substantially limit bacterial dissemination within and from the lungs, GI-19007 potentially can be used to limit lung damage as well as facilitating chemotherapeutic regimens in infected individuals.




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High-Definition Mapping of Four Spatially Distinct Neutralizing Epitope Clusters on RiVax, a Candidate Ricin Toxin Subunit Vaccine [Vaccines]

RiVax is a promising recombinant ricin toxin A subunit (RTA) vaccine antigen that has been shown to be safe and immunogenic in humans and effective at protecting rhesus macaques against lethal-dose aerosolized toxin exposure. We previously used a panel of RTA-specific monoclonal antibodies (MAbs) to demonstrate, by competition enzyme-linked immunosorbent assay (ELISA), that RiVax elicits similar serum antibody profiles in humans and macaques. However, the MAb binding sites on RiVax have yet to be defined. In this study, we employed hydrogen exchange-mass spectrometry (HX-MS) to localize the epitopes on RiVax recognized by nine toxin-neutralizing MAbs and one nonneutralizing MAb. Based on strong protection from hydrogen exchange, the nine MAbs grouped into four spatially distinct epitope clusters (namely, clusters I to IV). Cluster I MAbs protected RiVax's α-helix B (residues 94 to 107), a protruding immunodominant secondary structure element known to be a target of potent toxin-neutralizing antibodies. Cluster II consisted of two subclusters located on the "back side" (relative to the active site pocket) of RiVax. One subcluster involved α-helix A (residues 14 to 24) and α-helices F-G (residues 184 to 207); the other encompassed β-strand d (residues 62 to 69) and parts of α-helices D-E (154 to 164) and the intervening loop. Cluster III involved α-helices C and G on the front side of RiVax, while cluster IV formed a sash from the front to back of RiVax, spanning strands b, c, and d (residues 35 to 59). Having a high-resolution B cell epitope map of RiVax will enable the development and optimization of competitive serum profiling assays to examine vaccine-induced antibody responses across species.




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Development of a High-Throughput Respiratory Syncytial Virus Fluorescent Focus-Based Microneutralization Assay [Diagnostic Laboratory Immunology]

Neutralizing antibodies specific for respiratory syncytial virus (RSV) represent a major protective mechanism against RSV infection, as demonstrated by the efficacy of the immune-prophylactic monoclonal antibody palivizumab in preventing RSV-associated lower respiratory tract infections in premature infants. Accordingly, the RSV neutralization assay has become a key functional method to assess the neutralizing activity of serum antibodies in preclinical animal models, epidemiology studies, and clinical trials. In this study, we qualified a 24-h, fluorescent focus-based microneutralization (RSVA FFA-MN) method that requires no medium exchange or pre- or postinfection processing to detect green fluorescent protein-expressing RSV strain A2 (RSVA-GFP)-infected cells, using a high-content imaging system for automated image acquisition and focus enumeration. The RSVA FFA-MN method was shown to be sensitive, with a limit of detection (LOD) and limit of quantitation (LOQ) of 1:10, or 3.32 log2; linear over a range of 4.27 to 9.65 log2 50% inhibitory concentration (IC50); and precise, with intra- and interassay coefficients of variation of <21%. This precision allowed the choice of a statistically justified 3-fold-rise seroresponse cutoff criterion. The repeatability and robustness of this method were demonstrated by including a pooled human serum sample in every assay as a positive control (PC). Over 3 years of testing between two laboratories, this PC generated data falling within 2.5 standard deviations of the mean 98.7% of the time (n = 1,720). This high-throughput and reliable RSV microneutralization assay has proven useful for testing sera from preclinical vaccine candidate evaluation studies, epidemiology studies, and both pediatric and adult vaccine clinical trials.




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Development and Qualification of an Opsonophagocytic Killing Assay To Assess Immunogenicity of a Bioconjugated Escherichia coli Vaccine [Vaccines]

The global burden of disease caused by extraintestinal pathogenic Escherichia coli (ExPEC) is increasing as the prevalence of multidrug-resistant strains rises. A multivalent ExPEC O-antigen bioconjugate vaccine could have a substantial impact in preventing bacteremia and urinary tract infections. Development of an ExPEC vaccine requires a readout to assess the functionality of antibodies. We developed an opsonophagocytic killing assay (OPA) for four ExPEC serotypes (serotypes O1A, O2, O6A, and O25B) based on methods established for pneumococcal conjugate vaccines. The performance of the assay was assessed with human serum by computing the precision, linearity, trueness, total error, working range, and specificity. Serotypes O1A and O6A met the acceptance criteria for precision (coefficient of variation for repeatability and intermediate precision, ≤50%), linearity (90% confidence interval of the slope of each strain, 0.80, 1.25), trueness (relative bias range, –30% to 30%), and total error (total error range, –65% to 183%) at five serum concentrations and serotypes O2 and O25B met the acceptance criteria at four concentrations (the lowest concentration for serotypes O2 and O25B did not meet the system suitability test of maximum killing of ≥85% of E. coli cells). All serotypes met the acceptance criteria for specificity (opsonization index value reductions of ≤20% for heterologous serum preadsorption and ≥70% for homologous serum preadsorption). The assay working range was defined on the basis of the lowest and highest concentrations at which the assay jointly fulfilled the target acceptance criteria for linearity, precision, and accuracy. An OPA suitable for multiple E. coli serotypes has been developed, qualified, and used to assess the immunogenicity of a 4-valent E. coli bioconjugate vaccine (ExPEC4V) administered to humans.




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Editorial Board [Masthead]




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Anaplastic lymphoma kinase inhibitor-associated myositis

Anaplastic lymphoma kinase (ALK) inhibitors have been used in patients with non-small cell lung cancer (NSCLC) harboring EML4-ALK fusion gene.1 Severe skeletal muscle adverse events of ALK inhibitors, such as muscle weakness, have seldom been reported.2,3 Herein, we describe a patient who showed a severe skeletal muscle deficit after the administration of the ALK inhibitor, alectinib, and was successfully treated by corticosteroids without withdrawal from the cancer therapy.




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Single-cell RNA-seq analysis of human CSF microglia and myeloid cells in neuroinflammation

Objective

To identify and characterize myeloid cell populations within the CSF of patients with MS and anti-myelin oligodendrocyte glycoprotein (MOG) disorder by high-resolution single-cell gene expression analysis.

Methods

Single-cell RNA sequencing (scRNA-seq) was used to profile individual cells of CSF and blood from 2 subjects with relapsing-remitting MS (RRMS) and one with anti-MOG disorder. Publicly available scRNA-seq data from the blood and CSF of 2 subjects with HIV were also analyzed. An informatics pipeline was used to cluster cell populations by transcriptomic profiling. Based on gene expression by CSF myeloid cells, a flow cytometry panel was devised to examine myeloid cell populations from the CSF of 11 additional subjects, including individuals with RRMS, anti-MOG disorder, and control subjects without inflammatory demyelination.

Results

Common myeloid populations were identified within the CSF of subjects with RRMS, anti-MOG disorder, and HIV. These included monocytes, conventional and plasmacytoid dendritic cells, and cells with a transcriptomic signature matching microglia. Microglia could be discriminated from other myeloid cell populations in the CSF by flow cytometry.

Conclusions

High-resolution single-cell gene expression analysis clearly distinguishes distinct myeloid cell types present within the CSF of subjects with neuroinflammation. A population of microglia exists within the human CSF, which is detectable by surface protein expression. The function of these cells during immunity and disease requires further investigation.




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Clinical approach to the diagnosis of autoimmune encephalitis in the pediatric patient




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Is APOE {varepsilon}4 associated with cognitive performance in early MS?

Objective

To assess the impact of APOE polymorphisms on cognitive performance in patients newly diagnosed with clinically isolated syndrome (CIS) or relapsing-remitting MS (RRMS).

Methods

This multicenter cohort study included 552 untreated patients recently diagnosed with CIS or RRMS according to the 2005 revised McDonald criteria. The single nucleotide polymorphisms rs429358 (4) and rs7412 (2) of the APOE haplotype were assessed by allelic discrimination assays. Cognitive performance was evaluated using the 3-second paced auditory serial addition test and the Multiple Sclerosis Inventory Cognition (MUSIC). Sum scores were calculated to approximate the overall cognitive performance and memory-centered cognitive functions. The impact of the APOE carrier status on cognitive performance was assessed using multiple linear regression models, also including demographic, clinical, MRI, and lifestyle factors.

Results

APOE 4 homozygosity was associated with lower overall cognitive performance, whereas no relevant association was observed for APOE 4 heterozygosity or APOE 2 carrier status. Furthermore, higher disability levels, MRI lesion load, and depressive symptoms were associated with lower cognitive performance. Patients consuming alcohol had higher test scores than patients not consuming alcohol. Female sex, lower disability, and alcohol consumption were associated with better performance in the memory-centered subtests of MUSIC, whereas no relevant association was observed for APOE carrier status.

Conclusion

Along with parameters of a higher disease burden, APOE 4 homozygosity was identified as a potential predictor of cognitive performance in this large cohort of patients with CIS and early RRMS.




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Clinical and MRI phenotypes of sarcoidosis-associated myelopathy

Objective

To determine the characteristic clinical and spinal MRI phenotypes of sarcoidosis-associated myelopathy (SAM), we analyzed a large cohort of patients with this disorder.

Methods

Patients diagnosed with SAM at a single center between 2000 and 2018 who met the established criteria for definite and probable neurosarcoidosis were included in a retrospective analysis to identify clinical profiles, CSF characteristics, and MRI lesion morphology.

Results

Of 62 included patients, 33 (53%) were male, and 30 (48%) were African American. SAM was the first clinical presentation of sarcoidosis in 49 patients (79%). Temporal profile of symptom evolution was chronic in 81%, with sensory symptoms most frequently reported (87%). CSF studies showed pleocytosis in 79% and CSF-restricted oligoclonal bands in 23% of samples tested. Four discrete patterns of lesion morphology were identified on spine MRI: longitudinally extensive myelitis (n = 28, 45%), short tumefactive myelitis (n = 14, 23%), spinal meningitis/meningoradiculitis (n = 14, 23%), and anterior myelitis associated with areas of disc degeneration (n = 6, 10%). Postgadolinium enhancement was seen in all but 1 patient during the acute phase. The most frequent enhancement pattern was dorsal subpial enhancement (n = 40), followed by meningeal/radicular enhancement (n = 23) and ventral subpial enhancement (n = 12). In 26 cases (42%), enhancement occurred at locations with coexisting structural changes (e.g., spondylosis).

Conclusions

Recognition of the clinical features (chronically evolving myelopathy) and distinct MRI phenotypes (with enhancement in a subpial and/or meningeal pattern) seen in SAM can aid diagnosis of this disorder. Enhancement patterns suggest that SAM may have a predilection for areas of the spinal cord susceptible to mechanical stress.




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Ocrelizumab initiation in patients with MS: A multicenter observational study

Objective

To provide first real-world experience on patients with MS treated with the B cell–depleting antibody ocrelizumab.

Methods

We retrospectively collected data of patients who had received at least 1 treatment cycle (2 infusions) of ocrelizumab at 3 large neurology centers. Patients' characteristics including premedication, clinical disease course, and documented side effects were analyzed.

Results

We could identify 210 patients (125 women, mean age ± SD, 42.1 ± 11.4 years) who had received ocrelizumab with a mean disease duration of 7.3 years and a median Expanded Disability Status Scale score of 3.75 (interquartile range 2.5–5.5; range 0–8). Twenty-six percent of these patients had a primary progressive MS (PPMS), whereas 74% had a relapsing-remitting (RRMS) or active secondary progressive (aSPMS) disease course. Twenty-four percent of all patients were treatment naive, whereas 76% had received immune therapies before. After ocrelizumab initiation (median follow-up was 200 days, range 30–1,674 days), 13% of patients with RRMS/aSPMS experienced a relapse (accounting for an annualized relapse rate of 0.17, 95% CI 0.10–0.24), and 5% of all patients with MS experienced a 12-week confirmed disability progression. Treatment was generally well tolerated, albeit only short-term side effects were recorded, including direct infusion-related reactions and mild infections.

Conclusions

We provide class IV evidence that treatment with ocrelizumab can stabilize naive and pretreated patients, indicating that ocrelizumab is an option following potent MS drugs such as natalizumab and fingolimod. Further studies are warranted to confirm these findings and to reveal safety concerns in the longer-term follow-up.

Classification of evidence

This study provides Class IV evidence that for patients with MS, ocrelizumab can stabilize both treatment-naive and previously treated patients.




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Geospatial assessment methods for geotechnical asset management of legacy railway embankments

Most British railway embankments were constructed between 120 and 180 years ago without the benefit of modern design and construction methods. This can result in undesirable load-deformation characteristics and consequent disruption to present-day railway operations, for which there is unprecedented demand. Annual rail passenger kilometres have approximately doubled in the last 20 years and freight has increased by 60% over the same period. Whereas elements such as rails or bridges can be refurbished or replaced to meet increasing demand, the same is not usually feasible for embankments. Development of techniques to assess embankment performance risks posed by operational capacity enhancements is therefore of increasing significance to railway geotechnical asset management. The two case studies presented in this paper demonstrate how geospatial analysis and data management techniques may be applied to this challenge at both strategic (regional or national) and tactical (site-specific) scales for embankments incorporating plastic clay fill. The case studies also demonstrate, in a world of ever more abundant data, the growing need for engineering geologists and geotechnical engineers to augment their traditional knowledge with comprehensive data management and geospatial analysis skills, these being essential for modern infrastructure asset management.

Thematic collection: This article is part of the ‘Ground-related risk to transportation infrastructure’ collection available at: https://www.lyellcollection.org/cc/Ground-related-risk-to-transportation-infrastructure