Structural and functional basis of low-affinity SAM/SAH-binding in the conserved MTase of the multi-segmented Alongshan virus distantly related to canonical unsegmented flaviviruses.

Alongshan virus (ALSV), a newly discovered member of unclassified Flaviviridae family, is able to infect humans. ALSV has a multi-segmented genome organization and is evolutionarily distant from canonical mono-segmented flaviviruses. The virus-encoded methyltransferase (MTase) plays an important role in viral replication. Here we show that ALSV MTase readily binds S-adenosyl-L-methionine (SAM) and S-adenosyl-L-homocysteine (SAH) but exhibits significantly lower affinities than canonical flaviviral MTases. Structures of ALSV MTase in the free and SAM/SAH-bound forms reveal that the viral enzyme possesses a unique loop-element lining side-wall of the SAM/SAH-binding pocket. While the equivalent loop in flaviviral MTases half-covers SAM/SAH, contributing multiple hydrogen-bond interactions; the pocket-lining loop of ALSV MTase is of short-length and high-flexibility, devoid of any physical contacts with SAM/SAH. Subsequent mutagenesis data further corroborate such structural difference affecting SAM/SAH-binding. Finally, we also report the structure of ALSV MTase bound with sinefungin, an SAM-analogue MTase inhibitor. These data have delineated the basis for the low-affinity interaction between ALSV MTase and SAM/SAH and should inform on antiviral drug design.

Ischemic Heart-Derived Small Extracellular Vesicles Impair Adipocyte Function.

BACKGROUND: Patients with acute myocardial infarction suffer systemic metabolic dysfunction via incompletely understood mechanisms. Adipocytes play critical role in metabolic homeostasis. The impact of acute myocardial infarction upon adipocyte function is unclear. Small extracellular vesicles (sEVs) critically contribute to organ-organ communication. Whether and how small extracellular vesicle mediate post-MI cardiomyocyte/adipocyte communication remain unknown. METHODS: Plasma sEVs were isolated from sham control (Pla-sEVSham) or 3 hours after myocardial ischemia/reperfusion (Pla-sEVMI/R) and incubated with adipocytes for 24 hours. Compared with Pla-sEVSham, Pla-sEVMI/R significantly altered expression of genes known to be important in adipocyte function, including a well-known metabolic regulatory/cardioprotective adipokine, APN (adiponectin). Pla-sEVMI/R activated 2 (PERK-CHOP and ATF6 [transcription factor 6]-EDEM [ER degradation enhancing alpha-mannosidase like protein 1] pathways) of the 3 endoplasmic reticulum (ER) stress pathways in adipocytes. These pathological alterations were also observed in adipocytes treated with sEVs isolated from adult cardiomyocytes subjected to in vivo myocardial ischemia/reperfusion (MI/R) (Myo-sEVMI/R). Bioinformatic/RT-qPCR analysis demonstrates that the members of miR-23-27-24 cluster are significantly increased in Pla-sEVMI/R, Myo-sEVMI/R, and adipose tissue of MI/R animals. Administration of cardiomyocyte-specific miR-23-27-24 sponges abolished adipocyte miR-23-27-24 elevation in MI/R animals, supporting the cardiomyocyte origin of adipocyte miR-23-27-24 cluster. In similar fashion to Myo-sEVMI/R, a miR-27a mimic activated PERK-CHOP and ATF6-EDEM-mediated ER stress. Conversely, a miR-27a inhibitor significantly attenuated Myo-sEVMI/R-induced ER stress and restored APN production. RESULTS: An unbiased approach identified EDEM3 (ER degradation enhancing alpha-mannosidase like protein 3) as a novel downstream target of miR-27a. Adipocyte EDEM3 deficiency phenocopied multiple pathological alterations caused by Myo-sEVMI/R, whereas EDEM3 overexpression attenuated Myo-sEVMI/R-resulted ER stress. Finally, administration of GW4869 or cardiomyocyte-specific miR-23-27-24 cluster sponges attenuated adipocyte ER stress, improved adipocyte endocrine function, and restored plasma APN levels in MI/R animals. CONCLUSIONS: We demonstrate for the first time that MI/R causes significant adipocyte ER stress and endocrine dysfunction by releasing miR-23-27-24 cluster-enriched small extracellular vesicle. Targeting small extracellular vesicle-mediated cardiomyocyte-adipocyte pathological communication may be of therapeutic potential to prevent metabolic dysfunction after MI/R.

Perovskite light-emitting diodes based on spontaneously formed submicrometre-scale structures.

Light-emitting diodes (LEDs), which convert electricity to light, are widely used in modern society-for example, in lighting, flat-panel displays, medical devices and many other situations. Generally, the efficiency of LEDs is limited by nonradiative recombination (whereby charge carriers recombine without releasing photons) and light trapping1-3. In planar LEDs, such as organic LEDs, around 70 to 80 per cent of the light generated from the emitters is trapped in the device4,5, leaving considerable opportunity for improvements in efficiency. Many methods, including the use of diffraction gratings, low-index grids and buckling patterns, have been used to extract the light trapped in LEDs6-9. However, these methods usually involve complicated fabrication processes and can distort the light-output spectrum and directionality6,7. Here we demonstrate efficient and high-brightness electroluminescence from solution-processed perovskites that spontaneously form submicrometre-scale structures, which can efficiently extract light from the device and retain wavelength- and viewing-angle-independent electroluminescence. These perovskites are formed simply by introducing amino-acid additives into the perovskite precursor solutions. Moreover, the additives can effectively passivate perovskite surface defects and reduce nonradiative recombination. Perovskite LEDs with a peak external quantum efficiency of 20.7 per cent (at a current density of 18 milliamperes per square centimetre) and an energy-conversion efficiency of 12 per cent (at a high current density of 100 milliamperes per square centimetre) can be achieved-values that approach those of the best-performing organic LEDs.

The ratio of red blood cell distribution width to serum calcium predicts severity of patients with acute pancreatitis.

BACKGROUND: Illness severity of patients with acute pancreatitis (AP) at early stage is crucial because the identified moderate and severe cases need early intensive care to reduce the risk of serious complications such as multi-organ failure. Although red blood cell distribution width(RDW)and serum calcium(Ca)alone can be used as predictors of the severity of AP, they have low sensitivity and specificity. Thus, this study is aimed at evaluating the value of the ratio of RDW to serum calcium, which can all be acquired on admission, in predicting the severity of AP. METHODS: This study was based on a retrospective cohort study on patients with AP at the emergency department (ED) of West China Hospital Hospital from January 2016 to June 2016. We divided the patients with AP into two groups, mild acute pancreatitis (MAP) and moderate severe acute pancreatitis (MSAP) + severe acute pancreatitis (SAP). A receiver-operating characteristic (ROC) curve analysis was used to valuate the predictive value of the ratio of RDW to serum calcium for the severity of AP patients and the cut-off value for the ratio of RDW to serum calcium was calculated with sensitivity and specificity. P < 0.05 was considered statistically significant. RESULTS: A total of 666 AP patients were enrolled in this study. These patients were divided into MAP (n = 518) and MSAP+SAP (n = 148) groups. The AUC of RDW/ Ca was 0.912 (95% CI 0.887 to 0.937, P < 0.001), larger than the AUCs of RDW (AUC = 0.768, 95% CI 0.723 to 0.812, P < 0.001) and Ca (AUC = 0.875, 95% CI 0.844 to 0.906, P < 0.001). The optimal cut-off value for RDW/ Ca to predict MSAP and SAP was 7.04 (sensitivity = 0.885, specificity = 0.834). CONCLUSION: The RDW/Ca might be a valuable predictor of the severity of patients with AP.

[Transcriptomic microarray profiling of peripheral CD4+ T cells from asthmatic patients].

OBJECTIVE: To identify differentially expressed genes in peripheral blood mononuclear cells between patients with continuous mild-to-moderate asthma and healthy controls using mRNA microarray in order to explore the underlying signaling pathways and clarify the roles of CD4+ T cells in the pathogenesis of asthma. METHODS: Global transcriptomic profiles of the CD4+ T cells were defined by using Agilent Sure Print G3 Human GE 8×60K microarray. Enrichment pathways were analyzed with Ingenuity Pathway Analysis (IPA) software. RESULTS: Compared with controls, 805 genes were up-regulated, 192 were down-regulated in asthma patients. Among these, the expression of 38 annotated genes have varied by 4 times or more. Expression of CD300A was inversely proportional to the absolute value of eosinophils (r=-0.89, P=0.02) as well as the proportion of eosinophils (rs=-0.94, P=0.004), while CSF1R was inversely proportional to PD20 (rs=-0.83, P=0.04) and AQLQ (r=-0.88, P=0.02) by correlation analysis. CONCLUSION: Numerous pathophysiological pathways may be involved in the pathogenesis of asthma. Above findings have provided a basis for the delineation the pathogenesis of asthma.

Hypoalbuminemia predicts clinical outcome in patients with type B acute aortic dissection after endovascular therapy.

BACKGROUND: Few studies have reported that serum albumin (SA) levels on admission were associated with increased risk of long-term outcomes in patients with type B acute aortic dissection (AAD). The aim of this study was to investigate the effect of admission levels of SA on survival among patients with type B AAD undergoing endovascular therapy (EVT). METHODS: A total of 131 patients with type B AAD undergoing EVT were retrospectively enrolled and followed up for 2.1years. They were divided into hypoalbuminemia and nonhypoalbuminemia groups. We analyzed the incidence of inhospital complications and long-term mortality. Kaplan-Meier curves and multivariable Cox regression analyses were used to investigate the associations between SA levels and survival. RESULTS: Among 131 type B AAD patients, hypoalbuminemia was detected in 61 (46.6%) at admission. Compared to those without hypoalbuminemia, patients with hypoalbuminemia did not have higher inhospital complications; however, Kaplan-Meier analysis showed that they did have a significantly lower survival rate (73.8% vs 92.5%; log-rank χ(2)=9.8; P=.002). Multivariable Cox regression analysis further revealed that hypoalbuminemia was an independent predictor of long-term mortality among patients with type B AAD (hazard ratio, 4.28; 95% confidence interval, 1.36-13.47; P=.013), over 2.1years. CONCLUSIONS: Hypoalbuminemia is common in type B AAD patients and is independently associated with increased risk of long-term death. Renal dysfunction may be the main pathophysiological mechanism underlying hypoalbuminemia in patients with type B AAD.

[The Protective Effect of Target Temperature Management Combined with Prostaglandin E1 on Ischemia/Reperfusion Injury of Cerebral Micro-vascular Endothelium of ROSC Rat].

OBJECTIVE: To investigate the protective effect of target temperature management (TTM) combined with prostaglandin E1 (PGE1) on ischemia/reperfusion (I/R) injury of cerebral micro-vascular endothelium cell (CMEC) in the return of spontaneous circulation (ROSC) rats with successful cardiopulmonary resuscitation. METHODS: Transoesophageal cardiac pacing with alternating current was used to induce ventricular fibrillation in rats. Five groups were set: Sham group (S group), ROSC group (R group), PGE1 group (P group), TTM group (T group) and PGE1/TTM group (PT group). Cell edema and micro-thrombus formation in cerebral tissue were evaluated through HE staining. I/R injury of CMEC was evaluated through CD34/TUNEL and vascular endothelial (VE)-cadherin/VE growth factor receptor double fluorescent immunohistochemistry staining. VE-cadherin mRNA and vascular cell adhesion molecule-1 (VCAM-1) mRNA expression in cerebral tissue lysate was analyzed by fluorescence quantitative PCR. RESULTS: TTM, PGE1 and PGE1/TTM could significantly improve cerebral interstitial edema, micro-thrombus, and inflammatory cells infiltration in the brain tissue, and reduce the apoptosis and VE-cadherin protein loss of CMEC. PGE1/TTM showed better protective effect. These 3 interventions also inhibited the rapid elevation of VE-cadherin mRNA (0. 5 h) and VCAM-1 mRNA (4 h and 8 h) expression (P < 0.05), which might indicate the less I/R injury of CMEC of ROSC rat. CONCLUSION: Both PGE1 and TTM could alleviate I/R injury of CMEC from ROSC rat after CPR separately, while PGE1/TTM combined intervention might have synergistic better effect.

[Multivariate factors analysis on length of stay in Lushan earthquake victims].

OBJECTIVE: To clarify the factors associate with the length of stay (LOS) in Lushan Earthquake victims. METHODS: We retrospectively analyzed the medical information of 263 traumatic patients admitted to West China Hospital, Sichuan University after the Lushan Earthquake. Ten variables extracted for the analysis, including gender, age, injuried time, multiple injury, infection, comorbidities, Injury Severity Score (ISS), Revised Trauma Score (RTS) CRAMS score, and Prehospital Index (PHI). Univariable analysis using multiple stepwise regression analysis was performed to identify the factors associated with extended LOS. RESULTS: Infection, ISS score, and Pre-hospital Time were associated with extended LOS, and infection was the most weighted factor. The regression equation is: LOS (h) = 498.36 + 671.41 x Infection + 43.87 x ISS score - 5.12 x Pre-hospital Time. CONCLUSION: This study demonstrated that trauma patients with infections and high ISS scores were at increased risk for extended LOS and pre-hospital time decreased the risk.