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Background Anti‐SARS‐CoV‐2 S antibodies prevent viral replication. Critically ill COVID‐19 patients show viral material in plasma, associated with a dysregulated host response. If these antibodies influence survival and viral dissemination in ICU‐COVID patients is unknown. Patients/Methods We studied the impact of anti‐SARS‐CoV‐2 S antibodies levels on survival, viral RNA‐load in plasma, and N‐antigenaemia in 92 COVID‐19 patients over ICU admission. Results Frequency of N‐antigenaemia was >2.5‐fold higher in absence of antibodies. Antibodies correlated inversely with viral RNA‐load in plasma, representing a protective factor against mortality (Adjusted HR [CI 95%], p): (S IgM [AUC ≥ 60]: 0.44 [0.22; 0.88], 0.020); (S IgG [AUC ≥ 237]: 0.31 [0.16; 0.61]

Producción Científica, Background: Stratification of the severity of infection is currently based on the Sequential Organ Failure Assessment (SOFA) score, which is difficult to calculate outside the ICU. Biomarkers could help to stratify the severity of infection in surgical patients. Methods: Levels of ten biomarkers indicating endothelial dysfunction, 22 indicating emergency granulopoiesis, and six denoting neutrophil degranulation were compared in three groups of patients in the first 12 h after diagnosis at three Spanish hospitals. Results: There were 100 patients with infection, 95 with sepsis and 57 with septic shock. Seven biomarkers indicating endothelial dysfunction (mid-regional proadrenomedullin (MR-ProADM), syndecan 1, thrombomodulin, angiopoietin 2, endothelial cell-specific molecule 1, vascular cell adhesion molecule 1 and E-selectin) had stronger associations with sepsis than infection alone. MR-ProADM had the highest odds ratio (OR) in multivariable analysis (OR 11·53, 95 per cent c.i. 4·15 to 32·08; P = 0·006) and the best area under the curve (AUC) for detecting sepsis (0·86, 95 per cent c.i. 0·80 to 0·91; P < 0·001). In a comparison of sepsis with septic shock, two biomarkers of neutrophil degranulation, proteinase 3 (OR 8·09, 1·34 to 48·91; P = 0·028) and lipocalin 2 (OR 6·62, 2·47 to 17·77; P = 0·002), had the strongest association with septic shock, but lipocalin 2 exhibited the highest AUC (0·81, 0·73 to 0·90; P < 0·001). Conclusion: MR-ProADM and lipocalin 2 could be alternatives to the SOFA score in the detection of sepsis and septic shock respectively in surgical patients with infection., Instituto de Salud Carlos III (grants PI15/01959, PI15/01451 and PI16/01156)

Background The presence of SARS‐CoV‐2 RNA in plasma has been linked to disease severity and mortality. We compared RT‐qPCR to droplet digital PCR (ddPCR) to detect SARS‐CoV‐2 RNA in plasma from COVID‐19 patients (mild, moderate, and critical disease). Methods The presence/concentration of SARS‐CoV‐2 RNA in plasma was compared in three groups of COVID‐19 patients (30 outpatients, 30 ward patients and 30 ICU patients) using both RT‐qPCR and ddPCR. Plasma was obtained in the first 24h following admission, and RNA was extracted using eMAG. ddPCR was performed using Bio‐Rad SARS‐CoV‐2 detection kit, and RT‐qPCR was performed using GeneFinder™ COVID‐19 Plus RealAmp Kit. Statistical analysis was performed using Statistical Package for the Social Science. Results SARS‐CoV‐2 RNA was detected, using ddPCR and RT‐qPCR, in 91% and 87% of ICU patients, 27% and 23% of ward patients and 3% and 3% of outpatients. The concordance of the results obtained by both methods was excellent (Cohen's kappa index = 0.953). RT‐qPCR was able to detect 34/36 (94.4%) patients positive for viral RNA in plasma by ddPCR. Viral RNA load was higher in ICU patients compared with the other groups (P 85%). RT‐qPCR was as useful as ddPCR to detect and quantify SARS‐CoV‐2 RNAemia in plasma.

BackgroundSome patients infected by SARS-CoV-2 in the recent pandemic have required critical care, becoming one of the main limitations of the health systems. Our objective has been to identify potential markers at admission predicting the need for critical care in patients with COVID-19 pneumonia.MethodsWe retrospectively collected and analyzed data from electronic medical records of patients with laboratory-confirmed SARS-CoV-19 infection by real-time RT-PCR. A comparison was made between patients staying in the hospitalization ward with those who required critical care. Univariable and multivariable logistic regression methods were used to identify risk factors predicting critical care need.FindingsBetween March 15 and April 15, 2020, 150 patients under the age of 75 were selected (all with laboratory confirmed SARS-CoV-19 infection), 75 patients requiring intensive care assistance and 75 remaining the regular hospitalization ward. Most patients requiring critical care were males, 76% compared with 60% in the non-critical care group (pInterpretationPatients COVID-19 positive presenting at admission with high SOFA score ≥2 combined with CRP ≥ 9,1 mg/mL could help clinicians to identify them as a group that will more likely require critical care so further actions might be implemented to improve their prognosis.

Early recognition of sepsis is a key factor to improve survival to this disease in surgical patients, since it allows prompt control of the infectious source. Combining pro-inflammatory and immunosupression biomarkers could represent a good strategy to improve sepsis detection. Here we evaluated the combination of procalcitonin (PCT) with gene expression levels of HLA-DRA to detect sepsis in a cohort of 154 surgical patients (101 with sepsis and 53 with no infection). HLA-DRA expression was quantified using droplet digital PCR, a next-generation PCR technology. Area under the receiver operating curve analysis (AUROC) showed that the PCT/HLA-DRA ratio outperformed PCT to detect sepsis (AUROC [CI95%], p): PCT: 0.80 [0.73-0.88],0.001; PCT/HLA-DRA: 0.85 [0.78-0.91],0.001. In the multivariate analysis, the ratio showed a superior ability to predict sepsis compared to that of PCT (OR [CI 95%], p): PCT/HLA-DRA: 7.66 [1.82-32.29], 0.006; PCT: 4.21 [1.15-15.43] 0.030. Multivariate analysis was confirmed using a new surgical cohort with 74 sepsis patients and 21 controls: PCT/HLA-DRA: 34.86 [1.22-995.08], 0.038; PCT: 5.52 [0.40-75.78], 0.201. In conclusion, the combination of PCT with HLA-DRA is a promising strategy for improving sepsis detection in surgical patients.

In metazoans the AP-2 complex has a well-defined role in clathrin-mediated endocytosis. By contrast, its direct role in endocytosis in unicellular eukaryotes has been questioned. Here, we report co- immunoprecipitation between the fission yeast AP-2 component Apl3p and clathrin, as well as the genetic interactions between apl3Δ and clc1 and sla2Δ/end4Δ mutants. Furthermore, a double clc1 apl3Δ mutant was found to be defective in FM4-64 uptake. In an otherwise wild-type strain, apl3Δ cells exhibit altered dynamics of the endocytic sites, with a heterogeneous and extended lifetime of early and late markers at the patches. Additionally, around 50% of the endocytic patches exhibit abnormal spatial dynamics, with immobile patches and patches that bounce backwards to the cell surface, showing a pervasive effect of the absence of AP-2. These alterations in the endocytic machinery result in abnormal cell wall synthesis and morphogenesis. Our results complement those found in budding yeast and confirm that a direct role of AP-2 in endocytosis has been conserved throughout evolution.

Despite its biological and medical relevance, traffic from the Golgi to the plasma membrane (PM) is one of the least understood steps of secretion. Exomer is a protein complex that mediates the trafficking of certain cargoes from the trans-Golgi network/early endosomes to the PM in budding yeast. Here, we show that in Schizosaccharomyces pombe the Cfr1 and Bch1 proteins constitute the simplest form of an exomer. Cfr1 co-immunoprecipitates with Assembly Polypeptide adaptor 1 (AP-1), AP-2, and Golgi-localized, gamma-adaptin ear domain homology, ARF-binding (GGA) subunits, and cfr1+ interacts genetically with AP-1 and GGA genes. Exomer-defective cells exhibit multiple mild defects, including alterations in the morphology of Golgi stacks and the distribution of the synaptobrevin-like Syb1 protein, carboxypeptidase missorting, and stress sensitivity. S. pombe apm1Δ cells exhibit a defect in trafficking through the early endosomes that is severely aggravated in the absence of exomer. apm1Δ cfr1Δ cells exhibit a dramatic disorganization of intracellular compartments, including massive accumulation of electron-dense tubulovesicular structures. While the trans-Golgi network/early endosomes are severely disorganized in the apm1Δ cfr1Δ strain, gga21Δ gga22Δ cfr1Δ cells exhibit a significant disturbance of the prevacuolar/vacuolar compartments. Our findings show that exomer collaborates with clathrin adaptors in trafficking through diverse cellular compartments, and that this collaboration is important to maintain their integrity. These results indicate that the effect of eliminating exomer is more pervasive than that described to date, and suggest that exomer complexes might participate in diverse steps of vesicle transport in other organisms., Financial support from the Ministerio de Economía y Competitividad (Spain)/European Union FEDER program (BFU2013-48582-C2-2-P) and from Junta de Castilla y León (SA073U14) to M.-H.V., and from the Swiss National Science Foundation (310030B_163480) to A.S., made this work possible. M.-H.V. was supported by a Junta de Ampliación de Estudios (JAE)-PREDOC Consejo Superior de Investigaciones Científicas (CSIC) fellowship, and F.Y., S.M., N.d.L., and M.-A.C. were supported by Formación de Personal Universitario (FPU) fellowships from the Ministry of Education (Spain).

In metazoans the AP-2 complex has a well-defined role in clathrin-mediated endocytosis. By contrast, its direct role in endocytosis in unicellular eukaryotes has been questioned. Here, we report co- immunoprecipitation between the fission yeast AP-2 component Apl3p and clathrin, as well as the genetic interactions between apl3Δ and clc1 and sla2Δ/end4Δ mutants. Furthermore, a double clc1 apl3Δ mutant was found to be defective in FM4-64 uptake. In an otherwise wild-type strain, apl3Δ cells exhibit altered dynamics of the endocytic sites, with a heterogeneous and extended lifetime of early and late markers at the patches. Additionally, around 50% of the endocytic patches exhibit abnormal spatial dynamics, with immobile patches and patches that bounce backwards to the cell surface, showing a pervasive effect of the absence of AP-2. These alterations in the endocytic machinery result in abnormal cell wall synthesis and morphogenesis. Our results complement those found in budding yeast and confirm that a direct role of AP-2 in endocytosis has been conserved throughout evolution.

The involvement of Schizosaccharomyces pombe prm1+ in cell fusion during mating and its relationship with other genes required for this process have been addressed. S. pombe prm1Δ mutant exhibits an almost complete blockade in cell fusion and an abnormal distribution of the plasma membrane and cell wall in the area of cell-cell interaction. The distribution of cellular envelopes is similar to that described for mutants devoid of the Fig1-related claudin-like Dni proteins; however, prm1+ and the dni+ genes act in different subpathways. Time-lapse analyses show that in the wild-type S. pombe strain, the distribution of phosphatidylserine in the cytoplasmic leaflet of the plasma membrane undergoes some modification before an opening is observed in the cross wall at the cell- cell contact region. In the prm1Δ mutant, this membrane modification does not take place, and the cross wall between the mating partners is not extensively degraded; plasma membrane forms invaginations and fingers that sometimes collapse/retract and that are sometimes strengthened by the synthesis of cell-wall material. Neither prm1Δ nor prm1Δ dniΔ zygotes lyse after cell-cell contact in medium containing and lacking calcium. Response to drugs that inhibit lipid synthesis or interfere with lipids is different in wild-type, prm1Δ, and dni1Δ strains, suggesting that membrane structure/organization/dynamics is different in all these strains and that Prm1p and the Dni proteins exert some functions required to guarantee correct membrane organization that are critical for cell fusion. © 2014 by the Genetics Society of America., Financial support to H.V.M. from the Comisión Interministerial de Ciencia Y Tecnología (Spain)/European Union Fondo Europeo de Desarrollo Regional program (grant BFU2010-15085) made this work possible. M.A.C. and N.d.L were supported by Formación de Personal Universitario fellowships from the Ministry of Science, and M.H. was supported by a Junta de Ampliación de Estudios predoctoral fellowship from the Consejo Superior de Investigaciones Científicas, Spain.

This is an open-access article distributed under the terms of the Creative Commons Attribution License., In yeast, cytokinesis requires coordination between nuclear division, acto-myosin ring contraction, and septum synthesis. We studied the role of the Schizosaccharomyces pombe Bgs1p and Cfh3p proteins during cytokinesis under stress conditions. Cfh3p formed a ring in the septal area that contracted during mitosis; Cfh3p colocalized and co-immunoprecipitated with Cdc15p, showing that Cfh3p interacted with the contractile acto-myosin ring. In a wild-type strain, a significant number of contractile rings collapsed under stress conditions and this number increased dramatically in the cfh3Δ, bgs1cps1-191, and cfh3Δ bgs1/cps1-191. Our results show that after osmotic shock Cfh3p is essential for the stability of the (1,3) glucan synthase Bgs1p in the septal area, but not at the cell poles. Finally, cells adapted to stress; they repaired their contractile rings and re-localized Bgs1p to the cell surface some time after osmotic shock. A detailed analysis of the cytokinesis machinery in the presence of KCl revealed that the actomyosin ring collapsed before Bgs1p was internalized, and that it was repaired before Bgs1p re-localized to the cell surface. In the cfh3Δ, bgs1/cps1-191, and cfh3Δ bgs1/cps1-191 mutants, which have reduced glucan synthesis, the damage produced to the ring had stronger consequences, suggesting that an intact primary septum contributes to ring stability. The results show that the contractile actomyosin ring is very sensitive to stress, and that cells have efficient mechanisms to remedy the damage produced in this structure. © 2012 Sharifmoghadam et al., Financial support to the Instituto de Biología Funcional y Genómica (IBFG) from the Fundación Ramón Areces and to our group from the Comisión Interministerial de Ciencia y Tecnología (CICYT) (Spain)/European Union FEDER (Fondo Europeo de Desarrollo Regional) program (grant BFU2007-61866) made this work possible. Dr. Curto was supported by a contract for training in research and technological innovation by Junta de Castilla y León and by Formación de Personal Investigador (FPU) fellowship. Dr. de León and Dr. Hoya were supported by FPU and Junta de Ampliación de Estudios (JAE)-PREDOC fellowships from the Ministry of Science and Consejo Superior de Investigaciones Científicas (CSIC), Spain, respectively.

This is an open-access article distributed under the terms of the Creative Commons Attribution License., The regulation of cell wall synthesis by the clathrin light chain has been addressed. Schizosaccharomyces pombe clc1Δ mutant was inviable in the absence of osmotic stabilization; when grown in sorbitol-supplemented medium clc1Δ cells grew slowly, formed aggregates, and had strong defects in morphology. Additionally, clc1Δ cells exhibited an altered cell wall composition. A mutant that allowed modulating the amount of Clc1p was created to analyze in more detail the dependence of cell wall synthesis on clathrin. A 40% reduction in the amount of Clc1p did not affect acid phosphatase secretion and bulk lipid internalization. Under these conditions, β(1,3)glucan synthase activity and cell wall synthesis were reduced. Also, the delivery of glucan synthases to the cell surface, and the secretion of the Eng1p glucanase were defective. These results suggest that the defects in the cell wall observed in the conditional mutant were due to a defective secretion of enzymes involved in the synthesis/remodelling of this structure, rather than to their endocytosis. Our results show that a reduction in the amount of clathrin that has minor effects on general vesicle trafficking has a strong impact on cell wall synthesis, and suggest that this is the reason for the lethality of clc1Δ cells in the absence of osmotic stabilization., Financial support to our group from the MICINN (http://www.idi.mineco.gob.es/. Spain)/European Union FEDER program (grant BFU2010-15085) made this work possible. NdL and MAC were supported by FPU fellowships from the Ministry of Science, and MH was supported by a JAE-PREDOC fellowship from Consejo Superior de Investigaciones Cientificas, Spain.

RATIONALE: The identification of minimally invasive and easily-accessible biomarkers to support the management of coronavirus disease 2019 (COVID-19) in hospitalized patients constitutes a hot topic in clinical research. MicroRNAs (miRNAs) have been proposed as clinical indicators to assist in medical decision-making. Here, we aimed to examine the circulating miRNA profile of hospitalized COVID-19 patients and to evaluate its potential as a source of biomarkers for the management of the disease. METHODS: Observational, prospective and multicenter study which included 84 patients with a positive nasopharyngeal swab PCR test for SARS-CoV-2, recruited during the first pandemic wave in Spain (March-May 2020). Patients were stratified according to disease severity: hospitalized patients admitted to the clinical wards without requiring critical care (n = 47) and hospitalized patients admitted to the ICU (n = 37). An additional study considering ICU non-survivors (n=17) and survivors (n = 20) was performed. Expression profiling of 41 miRNAs was performed in plasma samples using RT-qPCR. The panel included miRNAs associated with: i) immune/inflammatory response;ii) lung damage;iii) respiratory viral infections;iv) myocardial damage;v) coagulation. Quality control was performed using spike-ins and hemolysis tests. Predictive models were constructed using a variable selection process based on LASSO regression. RESULTS: Ten circulating miRNAs were deregulated in ICU compared to ward patients. LASSO analysis identified a signature of three miRNAs that displayed an optimal discrimination ability to distinguish between ICU and ward patients (AUC = 0.88) (Figure 1A). Among ICU patients, six miRNAs were downregulated when comparing nonsurvivors to survivors. A signature based on two miRNAs was found to be a relevant predictor of mortality during ICU stay (AUC = 0.84) (Figure 1B). The discrimination potential of the miRNA signature was higher than the observed for clinical laboratory parameters such as leukocyte counts (including neutrophil count, lymphocyte count and the neutrophil-tolymphocyte ratio), CRP or D-dimer (maximum AUC for these variables = 0.76). CONCLUSIONS: The severity of COVID-19 impacts on the circulating miRNA profile. The results suggest the potential usefulness of the circulating miRNA signature for the management of the disease over contemporaneous tests, at least in ICU patients.