: We aim to comprehensively describe the transcriptional activity and signaling of pulmonary parenchymal and immune cells before and after cardiopulmonary bypass (CPB) by using a multi-omic approach ...coupled with functional cellular assays. We hypothesize that key signaling pathways from specific cells within the lung alter pulmonary endothelial cell function resulting in worsening or improving disease.
: We collected serial tracheobronchial lavage samples from intubated patients less than 2-years-old undergoing surgery with CPB. Samples were immediately processed for single cell RNA sequencing (10x Genomics). Cell clustering, cell-type annotation, and visualization were performed, and differentially expressed genes (DEG) between serial samples were identified. Metabolomic and proteomic analyses were performed on the supernatant using mass spectrometry and a multiplex assay (SomaScan) respectively. Functional assays were done using electric cell-substrate impedance sensing to measure resistance across human pulmonary microvascular endothelial cells (HPMECs).
: Analysis of eight patients showed a heterogeneous mixture of pulmonary parenchymal and immune cells. Cell clustering demonstrated time-dependent changes in the transcriptomic signature indicating altered cellular phenotypes after CPB. DEG analysis was represented by genes involved in host defense, innate immunity, and the mitochondrial respiratory transport chain. Ingenuity pathway analysis showed upregulation of the integrated stress response across all cell types after CPB. Metabolomic analysis demonstrated upregulation of ascorbate and aldarate metabolism. Unbiased proteomic analysis revealed upregulation of proteins involved in cytokine and chemokine pathways. Post-CPB patient supernatant improved HMPEC barrier function, suggesting a protective cellular response to CPB.
: Children who undergo CPB for cardiac surgery have distinct cell populations, transcriptional activity, and metabolism that change over time. The response to ischemia-reperfusion injury in the lower airway of children appears to be protective, with the need to identify potential targets through future investigations.
Many members of the mechanistically diverse enolase superfamily have unknown functions. In this report we use both genome (operon) context and screening of a library of acid sugars to assign the ...l-fuconate dehydratase (FucD) function to a member of the mandelate racemase (MR) subgroup of the superfamily encoded by the Xanthomonas campestris pv. campestris str. ATCC 33913 genome (GI:21233491). Orthologues of FucD are found in both bacteria and eukaryotes, the latter including the rTS beta protein in Homo sapiens that has been implicated in regulating thymidylate synthase activity. As suggested by sequence alignments and confirmed by high-resolution structures in the presence of active site ligands, FucD and MR share the same active site motif of functional groups: three carboxylate ligands for the essential Mg2+ located at the ends of the third, fourth, and fifth β-strands in the (β/α)7β-barrel domain (Asp 248, Glu 274, and Glu 301, respectively), a Lys-x-Lys motif at the end of the second β-strand (Lys 218 and Lys 220), a His-Asp dyad at the end of the seventh and sixth β-strands (His 351 and Asp 324, respectively), and a Glu at the end of the eighth β-strand (Glu 382). The mechanism of the FucD reaction involves initial abstraction of the 2-proton by Lys 220, acid catalysis of the vinylogous β-elimination of the 3-OH group by His 351, and stereospecific ketonization of the resulting enol, likely by the conjugate acid of Lys 220, to yield the 2-keto-3-deoxy-l-fuconate product. Screening of the library of acid sugars revealed substrate and functional promiscuity: In addition to l-fuconate, FucD also catalyzes the dehydration of l-galactonate, d-arabinonate, d-altronate, l-talonate, and d-ribonate. The dehydrations of l-fuconate, l-galactonate, and d-arabinonate are initiated by abstraction of the 2-protons by Lys 220. The dehydrations of l-talonate and d-ribonate are initiated by abstraction of the 2-protons by His 351; however, protonation of the enediolate intermediates by the conjugate acid of Lys 220 yields l-galactonate and d-arabinonate in competition with dehydration. The functional promiscuity discovered for FucD highlights possible structural mechanisms for evolution of function in the enolase superfamily.
Acute lung injury (ALI) and its most severe form, acute respiratory distress syndrome (ARDS), cause severe endothelial dysfunction in the lung, and vascular endothelial growth factor (VEGF) is ...elevated in ARDS. We found that the levels of a VEGF-regulated microRNA, microRNA-1 (miR-1), were reduced in the lung endothelium after acute injury. Pulmonary endothelial cell-specific (EC-specific) overexpression of miR-1 protected the lung against cell death and barrier dysfunction in both murine and human models and increased the survival of mice after pneumonia-induced ALI. miR-1 had an intrinsic protective effect in pulmonary and other types of ECs; it inhibited apoptosis and necroptosis pathways and decreased capillary leak by protecting adherens and tight junctions. Comparative gene expression analysis and RISC recruitment assays identified miR-1 targets in the context of injury, including phosphodiesterase 5A (PDE5A), angiopoietin-2 (ANGPT2), CNKSR family member 3 (CNKSR3), and TNF-α-induced protein 2 (TNFAIP2). We validated miR-1-mediated regulation of ANGPT2 in both mouse and human ECs and found that in a 119-patient pneumonia cohort, miR-1 correlated inversely with ANGPT2. These findings illustrate a previously unknown role of miR-1 as a cytoprotective orchestrator of endothelial responses to acute injury with prognostic and therapeutic potential.
Alcohol is a widely used and abused substance. A major unresolved issue in the alcohol research field is determining which of the many alcohol target proteins identified to date is responsible for ...shaping each specific alcohol-related behavior. The large-conductance, calcium- and voltage-activated potassium channel (BK channel) is a conserved target of ethanol. Genetic manipulation of the highly conserved BK
channel influences alcohol-related behaviors across phylogenetically diverse species that include worm, fly, mouse, and man. A pharmacological tool that prevents alcohol's action at a single target, like the BK channel, would complement genetic approaches in the quest to define the behavioral consequences of alcohol at each target. To identify agents that specifically modulate the action of ethanol at the BK channel, we executed a high-throughput phagemid-display screen in combination with a
behavioral genetics assay. This screen selected a novel nonapeptide, LS10, which moderated acute ethanol intoxication in a BK channel-humanized
strain without altering basal behavior. LS10's action in vivo was dependent upon BK channel functional activity. Single-channel electrophysiological recordings in vitro showed that preincubation with a submicromolar concentration of LS10 restricted ethanol-induced changes in human BK
channel gating. In contrast, no substantial changes in basal human BK
channel function were observed after LS10 application. The results obtained with the LS10 peptide provide proof-of-concept evidence that a combined phagemid-display/behavioral genetics screening approach can provide novel tools for understanding the action of alcohol at the BK channel and how this, in turn, exerts influence over central nervous system function.
Over the last century, outbreaks and pandemics have occurred with disturbing regularity, necessitating advance preparation and large-scale, coordinated response. Here, we developed a machine learning ...predictive model of disease severity and length of hospitalization for COVID-19, which can be utilized as a platform for future unknown viral outbreaks. We combined untargeted metabolomics on plasma data obtained from COVID-19 patients (n = 111) during hospitalization and healthy controls (n = 342), clinical and comorbidity data (n = 508) to build this patient triage platform, which consists of three parts: (i) the clinical decision tree, which amongst other biomarkers showed that patients with increased eosinophils have worse disease prognosis and can serve as a new potential biomarker with high accuracy (AUC = 0.974), (ii) the estimation of patient hospitalization length with ± 5 days error (R
= 0.9765) and (iii) the prediction of the disease severity and the need of patient transfer to the intensive care unit. We report a significant decrease in serotonin levels in patients who needed positive airway pressure oxygen and/or were intubated. Furthermore, 5-hydroxy tryptophan, allantoin, and glucuronic acid metabolites were increased in COVID-19 patients and collectively they can serve as biomarkers to predict disease progression. The ability to quickly identify which patients will develop life-threatening illness would allow the efficient allocation of medical resources and implementation of the most effective medical interventions. We would advocate that the same approach could be utilized in future viral outbreaks to help hospitals triage patients more effectively and improve patient outcomes while optimizing healthcare resources.
Abstract
One year of aerosol particle observations from Alert, Nunavut shows that new particle formation (NPF) is common during clean periods of the summertime Arctic associated with attendant low ...condensation sinks and with the presence of methane sulfonic acid (MSA), a product of the atmospheric oxidation of dimethyl sulfide (DMS). The clean aerosol time periods, defined using the distribution of refractory black carbon number concentrations, increase in frequency from June through August as the anthropogenic influence dwindles. During the clean periods, the number concentrations of particles that can act as cloud condensation nuclei (CCN) increase from June through August suggesting that DMS, and possibly other oceanic organic precursors, exert significant control on the Arctic summertime submicron aerosol, a proposition supported by simulations from the GEOS-Chem-TOMAS global chemical transport model with particle microphysics. The CCN increase for the clean periods across the summer is estimated to be able to increase cloud droplet number concentrations (CDNC) by 23–44 cm-3, comparable to the mean CDNC increase needed to yield the current global cloud albedo forcing from industrial aerosols. These results suggest that DMS may contribute significantly to modification of the Arctic summer shortwave cloud albedo, and they offer a reference for future changes in the Arctic summer aerosol.
Children undergoing cardiopulmonary bypass develop clinically impactful capillary leak of unclear etiology. A widely held hypothesis that exposure of circulating cells to the cardiopulmonary bypass ...circuit induces the release of inflammatory mediators that act to disrupt intercellular junctions of capillary endothelial cells inducing paracellular capillary leak either directly or through new gene expression.
Cohort study.
Tertiary pediatric hospital.
Twenty children undergoing surgery with cardiopulmonary bypass for congenital heart disease. Serum was collected before cardiopulmonary bypass, 2 hours after cardiopulmonary bypass, and 18 hours after cardiopulmonary bypass.
None.
We analyzed the effects of 10% patient sera on the "function, structure, and gene expression" of cultured human dermal and pulmonary microvascular endothelial cells. Changes in barrier "function" were measured using transendothelial electrical resistance. Associations between changes in transendothelial electrical resistance and subject characteristics were analyzed using linear mixed effects model with area under the resistance curve as outcome. Changes in junctional "structure" were assessed by analyzing the organization of the endothelial cell junctional proteins claudin-5 and VE-cadherin using immunofluorescence microscopy. Changes in inflammatory "gene expression" were measured using real-time quantitative reverse transcription-polymerase chain reaction. All serum samples induced a transient, 120-minute increase in transendothelial electrical resistance followed by persistent loss of barrier function. Unexpectedly, sera collected postcardiopulmonary bypass-induced significantly less loss of barrier function in both dermal and pulmonary capillary endothelial cell compared with precardiopulmonary bypass sera. Consistent with the transendothelial electrical resistance results, claudin-5 and vascular endothelial-cadherin junctional staining showed less disruption in cultures treated with postcardiopulmonary bypass sera. Expression of genes commonly associated with inflammation was largely unaffected by patient sera.
Contrary to the hypothesis, sera taken from children after cardiopulmonary bypass induces less capillary barrier disruption relative to sera taken from children before cardiopulmonary bypass, and none of the sera induced significant changes in expression of inflammatory genes.
Tissue engineering may address organ shortages currently limiting clinical transplantation. Off-the-shelf engineered vascularized organs will likely use allogeneic endothelial cells (ECs) to ...construct microvessels required for graft perfusion. Vasculogenic ECs can be differentiated from committed progenitors (human endothelial colony-forming cells or HECFCs) without risk of mutation or teratoma formation associated with reprogrammed stem cells. Like other ECs, these cells can express both class I and class II major histocompatibility complex (MHC) molecules, bind donor-specific antibody (DSA), activate alloreactive T effector memory cells, and initiate rejection in the absence of donor leukocytes. CRISPR/Cas9-mediated dual ablation of β2-microglobulin and class II transactivator (CIITA) in HECFC-derived ECs eliminates both class I and II MHC expression while retaining EC functions and vasculogenic potential. Importantly, dually ablated ECs no longer bind human DSA or activate allogeneic CD4+ effector memory T cells and are resistant to killing by CD8+ alloreactive cytotoxic T lymphocytes in vitro and in vivo. Despite absent class I MHC molecules, these ECs do not activate or elicit cytotoxic activity from allogeneic natural killer cells. These data suggest that HECFC-derived ECs lacking MHC molecule expression can be utilized for engineering vascularized grafts that evade allorejection.
Tintinnid species are traditionally distinguished via lorica features. Recently, sequencing has revealed polymorphism, i.e., genetically identical individuals with distinct lorica morphologies. One ...such polymorphic species is Cyttarocylis ampulla; individuals can display lorica morphologies of formally different species of Cyttarocylis and Petalotricha, well-represented in the literature. We compiled and analysed a global database of species records to determine if there is a main form and if different morphotypes have distinct temporal or spatial distributions. The two genera show very similar widespread distributions but with some statistical evidence of spatial segregation. Examining co-occurrence among the common ‘species’ we found most were rarely found alone, only 6-14% of the records for all species except for 2 forms: C. eucecryphalus and P. ampulla reported alone in 34% and 43%, respectively, of their records. We identify them as the main forms and analysed data of global distributions, spatial distribution across the Mediterranean in summer and winter and temporal distributions from a site in the Adriatic. The two main forms show frequent co-occurrence, similar lack of strong seasonality and widespread geographic distributions. We tentatively conclude that the different lorica morphologies may only reflect conditions of high temporally variability such as quantities and composition of prey. Directions for further research are suggested.
In 2014, the U.S. Public Health Service (USPHS) Commissioned Corps deployed to Monrovia, Liberia, to operate a 25-bed Ebola treatment unit (ETU) constructed by the U.S. Military. The ETU was named ...the Monrovia Medical Unit (MMU) and was constructed from an U.S. Air Force Expeditionary Medical Support (EMEDS) unit with modifications on the basis of consultation from Médecins Sans Frontières, the World Health Organization, and expert panels from the U.S. Department of Defense and Department of Health and Human Services. From November 12, 2014, to April 30, 2015, 42 patients (18 confirmed Ebola virus disease EVD and 24 suspected EVD) from nine countries were treated by USPHS providers at the MMU. The medications used in the MMU were primarily procured from the EMEDS 25-bed pharmacy cache. However, specific formulary additions were made for treatment of EVD.
Using the MMU pharmacy dispensing data, we compared and contrasted the medications used in the MMU with recommendations in published EVD treatment guidelines for austere settings.
After comparing and contrasting the MMU pharmacy dispensing data with publications with EVD medication recommendations applicable to resource-limited settings, 101 medications were included in the USPHS Essential Medications for the Management of EVD List (EML) for an austere, isolated clinical environment.
Because Ebola outbreaks often occur in remote areas, proactive planning, improved preparedness, and optimal patient care for EVD are needed, especially in the context of austere environments with a scarcity of resources. We developed the EML to assist in the planning for future Ebola outbreaks in a remote clinical environment and to provide a list of medications that have been used in an ETU. The EML is a comprehensive medication list that builds on the existing publications with EVD treatment recommendations applicable to supply-constrained clinical environments. As well, it is a resource for the provision of medications when evaluating donations, procurement, and may help inform estimates for product inventory requirements for an ETU. We hope the EML will improve readiness and enhance the capabilities of local and regional international responders.
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