WTAP-induced N6-methyladenosine of PD-L1 blocked T-cell-mediated antitumor activity under hypoxia in colorectal cancer.

N6-Methyladenosine (m6A) is a important process regulating gene expression post-transcriptionally. Programmed death ligand 1 (PD-L1) is a major immune inhibitive checkpoint that facilitates immune evasion and is expressed in tumor cells. In this research we discovered that Wilms' tumor 1-associated protein (WTAP) degradation caused by ubiquitin-mediated cleavage in cancer cells (colorectal cancer, CRC) under hypoxia was inhibited by Pumilio homolog 1 (PUM1) directly bound to WTAP. WTAP enhanced PD-L1 expression in a way that was m6A-dependent. m6A "reader," Insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) identified methylated PD-L1 transcripts and subsequently fixed its mRNA. Additionally, we found that T-cell proliferation and its cancer cell-killing effects were prevented by overexpression of WTAP in vitro and in vivo. Overexpression prevented T cells from proliferating and killing CRC by maintaining the expression of PD-L1. Further evidence supporting the WTAP-PD-L1 regulatory axis was found in human CRC and organoid tissues. Tumors with high WTAP levels appeared more responsive to anti-PD1 immunotherapy, when analyzing samples from patients undergoing treatment. Overall, our findings demonstrated a novel PD-L1 regulatory mechanism by WTAP-induced mRNA epigenetic regulation and the possible application of targeting WTAP as immunotherapy for tumor hypoxia.

Breaking Mass Transport Limitations by Iodized Polyacrylonitrile Anodes for Extremely Fast-Charging Lithium-Ion Batteries.

The fast-charging capability of rechargeable batteries is greatly limited by the sluggish ion transport kinetics in anode materials. Here we develop an iodized polyacrylonitrile (I-PAN) anode that can boost the bulk/interphase lithium (Li)-ion diffusion kinetics and accelerate Li-ion desolvation process to realize high-performance fast-charging Li-ion batteries. The iodine immobilized in I-PAN framework expands ion transport channels, compresses the electric double layer, and changes the inner Helmholtz plane to form LiF/LiI-rich solid electrolyte interphase layer. The dissolved iodine ions in the electrolyte self-induced by the interfacial nucleophilic substitution of PF6 - not only promote the Li-ion desolvation process, but also reuse the plated/dead Li formed on the anode under fast-charging conditions. Consequently, the I-PAN anode exhibits a high capacity of 228.5 mAh g-1 (39 % of capacity at 0.5 A g-1 delivered in 18 seconds) and negligible capacity decay for 10000 cycles at 20 A g-1 . The I-PAN||LiNi0.8 Co0.1 Mn0.1 O2 full cell shows excellent fast-charging performance with attractive capacities and negligible capacity decay for 1000 cycles at extremely high rates of 5 C and 10 C (1 C=180 mA g-1 ). We also demonstrate high-performance fast-charging sodium-ion batteries using I-PAN anodes.

Improving the genome and proteome annotations of the marine model diatom Thalassiosira pseudonana using a proteogenomics strategy.

Diatoms are unicellular eukaryotic phytoplankton that account for approximately 20% of global carbon fixation and 40% of marine primary productivity; thus, they are essential for global carbon biogeochemical cycling and climate. The availability of ten diatom genome sequences has facilitated evolutionary, biological and ecological research over the past decade; however, a complimentary map of the diatom proteome with direct measurements of proteins and peptides is still lacking. Here, we present a proteome map of the model marine diatom Thalassiosira pseudonana using high-resolution mass spectrometry combined with a proteogenomic strategy. In-depth proteomic profiling of three different growth phases and three nutrient-deficient samples identified 9526 proteins, accounting for ~ 81% of the predicted protein-coding genes. Proteogenomic analysis identified 1235 novel genes, 975 revised genes, 104 splice variants and 234 single amino acid variants. Furthermore, our quantitative proteomic analysis experimentally demonstrated that a considerable number of novel genes were differentially translated under different nutrient conditions. These findings substantially improve the genome annotation of T. pseudonana and provide insights into new biological functions of diatoms. This relatively comprehensive diatom proteome catalog will complement available diatom genome and transcriptome data to advance biological and ecological research of marine diatoms. Supplementary Information: The online version contains supplementary material available at 10.1007/s42995-022-00161-y.

Up-regulation of PUM1 by miR-218-5p promotes colorectal tumor-initiating cell properties and tumorigenesis by regulating the PI3K/AKT axis.

Background: Colorectal cancer (CRC) is the third most common cancer and the fourth most common cause of cancer-related death worldwide. Advanced stage CRC, during the recent past, had a dismal prognosis and only a few available treatments. Pumilio homologous protein 1 (PUM1) is reportedly aberrant in human malignancies, including CRC. However, the role of PUM1 in the regulation of tumor-initiating cells (T-ICs) remains unknown. Methods: The levels of messenger RNAs (mRNAs) were determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and immunoblot analyses. Statistical analyses were performed to determine the associations between the levels of PUM1 and tumor features and patient outcomes. Whether PUM1 is a downstream target of miR-218-5p was verified by bioinformatics target gene prediction and qRT-PCR. Results: Herein, it was found that T-ICs, chemoresistance, and recurrent CRC samples all manifest increased PUM1 expression. Functional investigations have shown that PUM1 increased the self-renewal, tumorigenicity, malignant proliferation, and chemoresistance of colorectal cells. PUM1 activates the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT) signaling pathway biochemically. Furthermore, it was discovered that miR-218-5p specifically targets T-ICs' PUM1 3'-untranslated region (3'-UTR). More importantly, the PUM1/PI3K/AKT axis regulates CRC cells' responses to treatment with cetuximab, and PUM1 overexpression increased cetuximab resistance. More evidence points to the possibility that low PUM1 may predict cetuximab benefits in CRC patients after analysis of the patient cohort, patient-derived tumor organoids, and patient-derived xenografts (PDXs). Conclusions: Taken together, the result of this work points to the critical function of the miR-218-5p/PUM1/PI3K/AKT regulatory circuit in regulating T-ICs characteristics and thus suggests possible therapeutic targets for CRC.

Effect of proprotein convertase subtilisin/kexin type 9 on platelet activation associated with sepsis / 中华危重病急救医学

Objective:To investigate the effect of proprotein convertase subtilisin/kexin type 9 (PCSK9) on platelet activation in sepsis.Methods:① Clinical trial: a prospective study was conducted. Patients with sepsis and septic shock aged ≥ 18 years old who met the diagnostic criteria of Sepsis-3 admitted to the department of intensive care medicine of the Affiliated Hospital of Binzhou Medical College from January to October in 2021 were selected as subjects. Healthy subjects in the same period were taken as healthy control group. Platelet count (PLT) in the first routine blood test after admission was recorded. Venous blood was taken 1 day after diagnosis, and serum PCSK9 level was determined by enzyme-linked immunosorbent assay (ELISA). The differences of PCSK9 level and PLT between the two groups were compared, and subgroup analysis was conducted based on PLT for patients with sepsis. The correlation between PCSK9 level and PLT in septic patients was analyzed by Pearson correlation method. ② Animal experiment: 80 male C57BL/6 mice were randomly divided into control group, sepsis model group [lipopolysaccharide (LPS) group], PCSK9 inhibitor pretreatment group (PCSK9 inhibitor+LPS group) and PCSK9 inhibitor control group (PCSK9 inhibitor group), with 20 mice in each group. The mouse model of sepsis was reproduced by intraperitoneal injection of LPS 12 mg/kg, and the control group and PCSK9 inhibitor group were intraperitoneally injected with the same amount of sterile normal saline. PCSK9 inhibitor+LPS group and PCSK9 inhibitor group were pretreated with PCSK9 inhibitor 5 mg/kg intraperitoneal injection for 7 days before injection of LPS or normal saline, respectively, and the control group and LPS group were injected with an equal amount of sterile normal saline. The lung tissues were taken for pathological and immunohistochemical observation 24 hours after modeling. Blood was taken from the heart for determining PLT. Platelet activation was detected by flow cytometry. The expression level of platelet-activation marker CD40L was detected by Western blotting.Results:① Clinical trial: there were 57 cases in the sepsis group and 27 cases in the healthy control group. Serum PCSK9 level in the sepsis group was significantly higher than that in the healthy control group (μg/L: 232.25±72.21 vs. 191.72±54.92, P < 0.05), and PLT was significantly lower than that in the healthy control group [×10 9/L: 146.00 (75.50, 204.50) vs. 224.00 (194.00, 247.00), P < 0.01]. Subgroup analysis showed that the serum PCSK9 level in the thrombocytopenia patients ( n = 20) was significantly higher than that in the non-thrombocytopenia patients ( n = 37; μg/L: 264.04±60.40 vs. 215.06±72.95, P < 0.01). Correlation analysis showed a significant negative correlation between serum PCSK9 levels and PLT in septic patients ( r = -0.340, P = 0.010). ② Animal experiment: there were no significant pathological changes in lung tissue in the control group and PCSK9 inhibitor group under light microscope, and no significant differences in PLT, platelet activation and plasma CD40L protein expression was found between the two groups. In the LPS group, a large number of inflammatory cells were infiltrated in the pulmonary interstitium, the alveolar structure was damaged obviously, the alveolar septum was widened, the alveolar cavity was extensively bleeding, the capillary dilatation with bleeding and platelet aggregation were found, the PLT was significantly decreased, the platelet activation and the expression level of CD40L protein in plasma were significantly increased. The infiltration of inflammatory cells in lung tissue of mice in the PCSK9 inhibitor+LPS group was reduced to a certain extent, the thickening of alveolar septa was reduced, the platelet aggregation in lung tissue was decreased as compared with the LPS group, the PLT was significantly increased (×10 9/L: 515.83±46.60 vs. 324.83±46.31, P < 0.05), the platelet activation and the expression level of CD40L protein in plasma were significantly decreased [positive expression rate of platelet activation dependent granule surface facial mask protein CD62P: (12.15±1.39)% vs. (18.33±2.74)%, CD40L protein (CD40L/β-actin): 0.77±0.08 vs. 1.18±0.10, both P < 0.05]. Conclusion:PCSK9 level has a certain effect on promoting platelet activation in sepsis, and inhibition of PCSK9 level may have potential research value in improving adverse outcomes caused by sepsis thrombocytopenia.

Effect of continuous blood purification on immunity and endothelial cell function in patients with sepsis / 中华危重病急救医学

Objective:To explore the effect of continuous blood purification (CBP) on the immunity and endothelial cell function of patients with sepsis.Methods:A prospective study was conducted. The patients aged ≥18 years old and meeting the diagnostic criteria of sepsis admitted to the department of critical care medicine of Binzhou Medical University Hospital from March 2019 to October 2020 were selected as the research subjects, and the patients were divided into standard treatment group and CBP treatment group according to random number table method. Both groups were given standard treatment including initial fluid resuscitation, infection source control and antibiotics according to the 2016 international guidelines for the management of sepsis and septic shock. CBP treatment group was additionally given continuous veno-venous hemofiltration (CVVH) at a dose of 25-30 mL·kg -1·h -1 and blood flow rate of 150-200 mL/min for more than 20 hours a day for 3 days. The clinical data of patients including blood lactic acid (Lac), procalcitonin (PCT), lymphocyte count (LYM), acute physiology and chronic health evaluationⅡ(APACHEⅡ) score, sequential organ failure assessment (SOFA) score were recorded before treatment and 1 day and 3 days after treatment. At the same time, the venous blood was collected, and the immune function related indexes [interleukins (IL-4, IL-7), programmed death receptor-1 (PD-1), programmed death ligand-1 (PD-L1), interferon-γ (IFN-γ)] and endothelial cell injury related markers [soluble thrombomodulin (sTM), angiopoietin-2 (Ang-2), von Willebrand factor (vWF), heparan sulfate (HS), syndecan-1 (SDC-1)] levels in serum were determined by enzyme-linked immunosorbent assay (ELISA). The length of intensive care unit (ICU) stay of patients in the two groups was recorded, and the outcomes of patients in the two groups were followed up for 28 days. Results:Finally, 20 patients were enrolled in the standard treatment group, and 19 patients were enrolled in the CBP treatment group. There were no significant differences in gender, age and infection site between the two groups. The length of ICU stay in the standard treatment group was (10±5) days, and 5 patients died and 15 patients survived after 28 days. The length of ICU stay in the CBP treatment group was (9±4) days, and 8 patients died and 11 patients survived after 28 days. There were no significant differences in the length of ICU stay and number of patients who died within 28 days between the two groups (both P > 0.05). There were no significant differences in the Lac, PCT, LYM, APACHEⅡ score, SOFA score and immune function and endothelial cell injury related indexes before treatment and 1 day after treatment between the two groups. After 3 days of treatment, the Lac, PCT, APACHEⅡ score and SOFA score of the CBP treatment group were significantly lower than those before treatment, and pro-inflammatory and anti-inflammatory cytokines such as IFN-γ and IL-4, apoptosis-related indicators such as PD-1 and IL-7, and endothelial injury related factors such as sTM, SDC-1 and HS were significantly improved compared with the pre-treatment, the improvement degree of the above indicators was more obvious than that of the standard treatment group, and LYM was significantly higher than that of the standard treatment group (×10 9/L: 1.3±0.3 vs. 0.9±0.4, P < 0.05), IL-4, IFN-γ, IFN-γ/IL-4 ratio, IL-7, PD-1, sTM, SDC-1, HS, and Ang-2 were significantly lower than those of the standard treatment group [IL-4 (ng/L): 2.8 (1.5, 3.2) vs. 3.3 (2.7, 5.2), IFN-γ (ng/L): 6.3 (5.4, 106.5) vs. 217.9 (71.4, 517.1), IFN-γ/IL-4 ratio: 3.7 (1.8, 70.3) vs. 59.1 (18.3, 124.9), IL-7 (ng/L): 4.6 (3.2, 5.1) vs. 6.3 (5.2, 8.0), PD-1 (μg/L): 0.04 (0.03, 0.06) vs. 0.08 (0.05, 0.12), sTM (μg/L): 4.9 (4.3, 7.4) vs. 8.7 (6.0, 10.8), SDC-1 (μg/L): 0.6 (0.3, 1.1) vs. 0.9 (0.8, 2.5), HS (ng/L): 434.8 (256.2, 805.0) vs. 887.9 (620.1, 957.3), Ang-2 (ng/L): 934.0 (673.3, 1 502.1) vs. 2 233.9 (1 472.5, 3 808.4)], the differences were statistically significant (all P < 0.05). Conclusion:CBP treatment can eliminate the patient's immunosuppressive state, reduce a variety of endothelial injury markers and the degradation of glycocalyx, but cannot decrease the 28-day death risk or shorten the length of ICU stay.

Laboratory Monitoring of Non-Vitamin K Antagonist Oral Anticoagulants and Their Use in Special Populations / 中山大学学报(医学科学版)

In the past few decades， heparin and warfarin have been the main anticoagulants used to treat and prevent venous thromboembolism. Recent studies at home and abroad have shown that non-vitamin K antagonist oral anticoagulants （NOACs） have similar or better efficacy and safety in the prevention and treatment of venous thromboembolism and non-valvular atrial fibrillation. NOACs do not require routine coagulation monitoring when used at a fixed dose. However， in special populations or specific scenarios such as emergency surgery， etc.， an overdose or underdose and abnormal metabolism of NOACs may reduce the drug efficacy and safety， so monitoring and evaluating the anticoagulant effect of NOACs is more conducive to the prognosis of patients.This paper briefly reviewed the common laboratory monitoring methods of NOACs and their use in special populations， aiming to explain different monitoring methods for different NOACs and the applicability of NOACs in special populations， and hoping to provide reference for clinical standard monitoring and use of NOACS.

Irisin inhibits myocardial injury induced by cobalt dichloride through regulating Sirtl/UCP2 pathway / 中国药理学通报

Aim To investigate the role and specific mechanisms of muscle factor Irisin in regulating the intracellular protective protein Sirtl and mitochondrial uncoupling protein 2 (UCP2) during myocardial hypoxia. Methods H9c2 cells were treated with CoC12 for 24 hours to construct an in vitro hypoxia model of myocardial cells. Six groups were divided in this experiment; control group (control), Irisin group (10 nmol • L

Predictive Effects of Different Insulin Resistance Indexes on Diabetes Risk in Hypertensive Population / 中国医学科学院学报

Objective To explore the roles of different insulin resistance indexes[triglyceride-glucose (TyG),triglyceride (TG)/high-density lipoprotein cholesterol (HDL-C),and metabolic score for insulin resistance (METS-IR)]and combinations of two indexes in predicting diabetes risk in hypertensive population. Methods The survey of hypertension was conducted for the residents in Wuyuan county,Jiangxi province from March to August in 2018.The basic information of hypertensive residents was collected by interview.Blood was drawn on an empty stomach in the morning and physical measurements were carried out.Logistic regression model was employed to analyze the relationship between different insulin resistance indexes and diabetes,and the area under the receiver operating characteristic curve was used for evaluating the predictive effects of each index on diabetes risk. Results A total of 14 222 hypertensive patients with an average age of (63.8±9.4) years old were included in this study,including 2616 diabetic patients.The diabetic hypertensive population had higher TyG (t=50.323,P<0.001),TG/HDL-C (Z=17.325,P<0.001),and METS-IR (t=28.839,P<0.001) than the non-diabetic hypertensive population.Multivariate analysis showed that each insulin resistance index was positively correlated with diabetes risk.The area under curve of each insulin index was in a descending order of TyG (0.770)> METS-IR (0.673)> TG/HDL-C (0.620).The difference in the area under curve between two indexes was statistically significant[TyG vs.TG/HDL-C (Z=42.325,P<0.001);TyG vs.METS-IR(Z=17.517,P<0.001);METS-IR vs.TG/HDL-C (Z=10.502,P<0.001)]. Conclusions Elevated insulin resistance indexes can increase the risk of diabetes.TyG and the combination of indexes outperform TG/HDL-C and METS-IR in the prediction of diabetes.

A 3D structure C/Si/ZnCo2O4/CC anode for flexible lithium-ion batteries with high capacity and fast charging ability.

ZnCo2O4 has attracted extensive attention as a bimetallic transition metal oxide anode material for lithium-ion batteries (LIBs) with high capacity. However, there is still a long way to go to meet the increasing demand for commercial batteries due to their modest conductivity and unobtrusive cycling stability. The use of finely controlled nanostructures and combination with other anode materials are the two main ways to improve the battery performance of ZnCo2O4. Herein, ZnCo2O4 (ZCO) nanosheets were in situ grown on carbon cloth (CC) through a facile solution method. Si was coated onto the ZCO nanosheet arrays by the magnetron sputtering method (SCZO/CC) to acheive the capacity increase. A layer of C was further coated onto SZCO/CC to improve the electrical conductivity of the whole electrode and to protect the SZCO nanostructure. The obtained CSZCO/CC electrode exhibits a high reversible areal capacity of 1.16 mA h cm-2 at 5 mA cm-2 after 500 cycles. At an ultra-high current density of 10 mA cm-2, the CSZCO/CC electrode can still present a capacity of 0.38 mA h cm-2 and maintain a capacity retention of 88.4% for 2000 cycles. In situ Raman spectroscopy was used to study the relationship between the electrochemical performance and structure of the electrode materials. The carbon cloth was found to have contributed a nonnegligible part of the capacity of the electrode.

Efficacy and Safety of Dapagliflozin versus Liraglutide in Patients with Overweight or Obesity and Type 2 Diabetes Mellitus: A Randomised Controlled Clinical Trial in Tianjin, China.

Objective: We aimed to clarify the efficacy of dapagliflozin versus liraglutide in patients with overweight or obesity and type 2 diabetes mellitus (T2DM) at the beginning of the coronavirus disease 2019 (COVID-19) pandemic. Methods: T2DM patients with overweight or obesity who visited the Metabolic Disease Management Center at Tianjin Fourth Central Hospital from October 2019 to January 2020 were recruited and randomised to receive dapagliflozin or liraglutide for 24 weeks. Changes in blood glucose and lipid levels, blood pressure, and body weight, as well as the occurrence of hypoglycaemia and other adverse events, were compared. Results: 309 patients completed the study (143 in liraglutide group and 166 in dapagliflozin group). After 24 weeks, HbA1c, fasting blood glucose (FPG), and 2 h postprandial blood glucose (2hPG) levels significantly decreased from 8.80% ± 1.41% to 7.02% ± 1.05%, 10.41 ± 3.13 to 7.59 ± 2.16 mmol/L, and 17.90 ± 4.39 to 10.12 ± 2.47 mmol/L, respectively, in the dapagliflozin group, and from 8.92% ± 1.49% to 6.78% ± 1.00%, 10.04 ± 2.99 to 7.20 ± 1.63 mmol/L, and 17.30 ± 4.39 to 10.13 ± 4.15 mmol/L, respectively, in the liraglutide group. Changes in HbA1c, FPG, and 2hPG levels between groups were not significantly different. Systolic blood pressure (SBP) and low-density lipoprotein cholesterol (LDL-C) level significantly decreased from 144.1 ± 19.1 to 139.7 ± 16.2 mmHg (p = 0.001) and from 3.21 ± 0.94 to 2.98 ± 0.89 mmol/L (p = 0.014), respectively, in the dapagliflozin group. After COVID-19 outbreak, the number of patients taking sleep-promoting drugs increased from 4.9% to 9.4% (p = 0.029). Conclusions: Liraglutide and dapagliflozin had strong hypoglycaemic effects in patients with overweight or obesity and T2DM at the beginning of the COVID-19 pandemic. Dapagliflozin may be beneficial in improving SBP and LDL-C levels; however, further research is warranted.

Responses of nickel bioavailability and toxicity of Prorocentrum Donghaienses to dissolved organic matter (DOM) fractions incubated in urea.

Urea, nickel (Ni) and dissolved organic matter (DOM) from land varied with different sources have a great impact on the offshore ecosystem. The heterogeneity of Ni bioavailability and toxicity of Prorocentrum donghaiense influenced by DOM fractions incubated in urea was investigated in this study. On the occasion, chlorophyll (Chl a) concentration, growth rate, and photosynthesis parameters were monitored to track changes occurring in the test organism. Chl a concentration and photosynthesis parameters in the treatment of hydrophilic DOM (HPI) with Ni-free was significantly higher than that in the control treatment, and similar data were shown in the treatment of hydrophobic DOM（HPO）with the low Ni environment (0.17µmol L-1). However, the opposite phenomena were observed in the treatments of HPO with the higher Ni environment (over 170µmol L-1). Moreover, the EC50 of Ni for P.donghaiense incubated in HPO was relatively lower than that in HPI and control treatment, which implied that HPO elevated the toxicity of Ni. Therefore, the varied DOM compositions because of different origins, as a chelating agent and potential nutrient source in coastal waters, shows the significantly different bioavailability and toxicity of Ni with the increasing inputs of urea, which in turn influences the dynamics of phytoplankton.

c-MYC-mediated TRIB3/P62+ aggresomes accumulation triggers paraptosis upon the combination of everolimus and ginsenoside Rh2.

The mammalian target of rapamycin (mTOR) pathway is abnormally activated in lung cancer. However, the anti-lung cancer effect of mTOR inhibitors as monotherapy is modest. Here, we identified that ginsenoside Rh2, an active component of Panax ginseng C. A. Mey., enhanced the anti-cancer effect of the mTOR inhibitor everolimus both in vitro and in vivo. Moreover, ginsenoside Rh2 alleviated the hepatic fat accumulation caused by everolimus in xenograft nude mice models. The combination of everolimus and ginsenoside Rh2 (labeled Eve-Rh2) induced caspase-independent cell death and cytoplasmic vacuolation in lung cancer cells, indicating that Eve-Rh2 prevented tumor progression by triggering paraptosis. Eve-Rh2 up-regulated the expression of c-MYC in cancer cells as well as tumor tissues. The increased c-MYC mediated the accumulation of tribbles homolog 3 (TRIB3)/P62+ aggresomes and consequently triggered paraptosis, bypassing the classical c-MYC/MAX pathway. Our study offers a potential effective and safe strategy for the treatment of lung cancer. Moreover, we have identified a new mechanism of TRIB3/P62+ aggresomes-triggered paraptosis and revealed a unique function of c-MYC.

Cryo-EM structures of SARS-CoV-2 Omicron BA.2 spike

The BA.2 sub-lineage of the SARS-CoV-2 Omicron variant has gained in proportion relative to BA.1. As differences in spike (S) proteins may underlie differences in their pathobiology, here we determine cryo-EM structures of a BA.2 S ectodomain and compare these to previously determined BA.1 S structures. BA.2 Receptor Binding Domain (RBD) mutations induced remodeling of the internal RBD structure resulting in its improved thermostability and tighter packing within the 3-RBD-down spike. In the S2 subunit, the fusion peptide in BA.2 was less accessible to antibodies than in BA.1. Pseudovirus neutralization and spike binding assays revealed extensive immune evasion while defining epitopes of two RBD-directed antibodies, DH1044 and DH1193, that bound the outer RBD face to neutralize both BA.1 and BA.2. Taken together, our results indicate that stabilization of the 3-RBD-down state through interprotomer RBD-RBD packing is a hallmark of the Omicron variant, and reveal differences in key functional regions in the BA.1 and BA.2 S proteins.

Structural diversity of the SARS-CoV-2 Omicron spike

Aided by extensive spike protein mutation, the SARS-CoV-2 Omicron variant overtook the previously dominant Delta variant. Spike conformation plays an essential role in SARS-CoV-2 evolution via changes in receptor binding domain (RBD) and neutralizing antibody epitope presentation affecting virus transmissibility and immune evasion. Here, we determine cryo-EM structures of the Omicron and Delta spikes to understand the conformational impacts of mutations in each. The Omicron spike structure revealed an unusually tightly packed RBD organization with long range impacts that were not observed in the Delta spike. Binding and crystallography revealed increased flexibility at the functionally critical fusion peptide site in the Omicron spike. These results reveal a highly evolved Omicron spike architecture with possible impacts on its high levels of immune evasion and transmissibility.

Anticancer Effects of Ginsenoside Rh2: A Systematic Review.

BACKGROUND: As one of the effective pharmacological constituents of Ginseng Radix et Rhizoma, ginsenoside Rh2 (Rh2) exerts a remarkable anticancer effect on various cancer cell lines in vitro and strongly inhibits tumor growth in vivo without severe toxicity. OBJECTIVE: This article reviewed existing evidence supporting the anticancer effects of Rh2 to classify and conclude previous and current knowledge on the mechanisms and therapeutic effects of Rh2, as well as to promote the clinical application of this natural product. CONCLUSION: This article reviewed the anticancer efficacies and mechanisms of Rh2, including the induction of cell cycle arrest and programmed cell death, repression of metastasis, alleviation of drug resistance, and regulation of the immune system. Finally, this paper discussed the research and application prospects of Rh2.

Mechanism of high mobility group protein B1 in lipopolysaccharide-induced acute lung injury/acute respiratory distress syndrome / 中华危重病急救医学

Objective:To investigate the role and possible pathogenesis of high mobility group protein B1 (HMGB1) in lipopolysaccharide (LPS)-induced acute lung injury/acute respiratory distress syndrome (ALI/ARDS).Methods:① In vivo, 24 SPFC57BL/6 male mice were randomly divided into normal control group, ALI/ARDS model group, ethyl pyruvate (EP) treatment group and EP control group, with 6 mice in each group. The ALI/ARDS model was established by intraperitoneal injection of 20 mg/kg LPS. Mice in normal control group and EP control group were intraperitoneally injected with the same amount of sterile normal saline. Then, mice in the EP treatment group and EP control group were intraperitoneally injected with 40 mg/kg HMGB1 inhibitor EP. After 6 hours, the mice were sacrificed and lung tissues were collected. The expressions of heparan sulfate (HS), syndecans-1 (SDC-1), heparanase (HPA) and matrix metalloproteinases-9 (MMP-9) in lung tissues were detected by immunofluorescence technique. Orbital blood of mice was collected and serum was extracted to detect the content of HMGB1 by enzyme linked immunosorbent assay (ELISA). ② In vitro, human umbilical vein endothelial cells (HUVECs) were randomly divided into 6 groups: normal control group, HUVECs damage group (treated with 1 mg/L LPS for 6 hours), HMGB1 group (treated with 1 μmol/L recombinant HMGB1 for 6 hours), HMGB1+EP group (treated with recombinant HMGB1 for 1 hour and then added 1 μmol/L EP for 6 hours), LPS+EP group (treated with LPS for 1 hour and then added 1 μmol/L EP for 6 hours), EP group (treated with 1 μmol/L EP for 6 hours). The expressions of HS, SDC-1, HPA and MMP-9 in endothelial cells were detected by immunofluorescence technique. Results:① In vivo, light microscopy showed that the alveolar space was thickened after LPS stimulation, and there were a large number of inflammatory cells infiltrating in the alveolar space. Compared with ALI/ARDS model group, the expressions of HS and SDC-1 in lung tissue of EP treatment group were significantly increased [HS (fluorescence intensity): 0.80±0.20 vs. 0.53±0.02, SDC-1 (fluorescence intensity): 0.72±0.02 vs. 0.51±0.01, both P < 0.05], and the expressions of HPA and MMP-9 were significantly decreased [HPA (fluorescence intensity): 2.36±0.05 vs. 3.00±0.04, MMP-9 (fluorescence intensity): 2.55±0.13 vs. 3.26±0.05, both P < 0.05]; there were no significant changes of the above indexes in EP control group. Compared with ALI/ARDS model group, the content of serum HMGB1 in EP treatment group decreased significantly (μg/L: 131.88±16.67 vs. 341.13±22.47, P < 0.05); there was no significant change in the EP control group. ② In vitro, compared with HMGB1 group, the expressions of HS and SDC-1 in HMGB1+EP group were significantly higher [HS (fluorescence intensity): 0.83±0.07 vs. 0.56±0.03, SDC-1 (fluorescence intensity): 0.80±0.01 vs. 0.61±0.01, both P < 0.05], and the expressions of HPA and MMP-9 were significantly lower [HPA (fluorescence intensity): 1.30±0.02 vs. 2.29±0.05, MMP-9 (fluorescence intensity): 1.55±0.04 vs. 2.50±0.06, both P < 0.05]; the expression of HS, SDC-1, HPA and MMP-9 had no significant changes in EP group. Conclusion:HMGB1 participates in LPS-induced injury of endothelial cell glycocalyx, leading to increased lung permeability, and inhibition of HMGB1 can alleviate lung injury.

Prognostic value of PCSK9 and blood lipid in patients with sepsis / 中华危重病急救医学

Objective:To investigate the prognostic value of proprotein convertase subtilisin/kexin type 9 (PCSK9) and blood lipid indexes in patients with sepsis.Methods:Patients with sepsis or septic shock who were ≥ 18 years old and met the Sepsis-3.0 diagnostic criteria admitted to the department of critical care medicine of Binzhou Medical University Hospital from January to October 2021 were enrolled. Healthy adults at the same period were selected as healthy control group. Baseline characteristics, acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) and sequential organ failure assessment (SOFA) score were recorded. Venous blood samples were collected within 24 hours after diagnosis, and serum PCSK9 was determined by enzyme-linked immunosorbent assay (ELISA) at 1, 3 days and 5 days. Meanwhile, high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), total cholesterol (TC), triglyceride (TG) and lipoprotein A were detected. The differences of each index between sepsis group (28-day death group and survival group) and healthy control group were compared. Meanwhile, the indexes of patients with different severity and 28-day prognosis in sepsis group were compared. Receiver operator characteristic curve (ROC curve) was drawn to evaluate the predictive value of PCSK9 and blood lipid for the prognosis of sepsis. Multivariate Logistic regression was used to analyze the influencing factors for the prognosis of sepsis, and the Kaplan-Meier survival curve at 28th day was drawn.Results:There were 50 patients in sepsis group (including 19 patients with sepsis, 31 patients with septic shock) and 27 patients in healthy control group. In the sepsis group, 19 patients died and 31 patients survived within 28 days. The serum PCSK9 in the sepsis group was significantly higher than that in the healthy control group [μg/L: 223.09 (198.47, 250.82) vs. 188.00 (165.27, 214.90), P < 0.01], and HDL-C, LDL-C, TC and lipoprotein A were significantly lower than those in the healthy control group [HDL-C (mmol/L): 0.82±0.35 vs. 1.45±0.24, LDL-C (mmol/L): 1.53 (1.14, 2.47) vs. 2.89 (2.55, 3.19), TC (mmol/L): 2.03 (1.39, 2.84) vs. 4.24 (3.90, 4.71), lipoprotein A (g/L): 8.80 (5.66, 17.56) vs. 27.03 (14.79, 27.03), all P < 0.01]. PCSK9 in the sepsis death group was higher than that in the survival group [μg/L: 249.58 (214.90, 315.77) vs. 207.01 (181.50, 244.95), P < 0.01], and the HDL-C, LDL-C and TC were lower than those in the survival group [HDL-C (mmol/L): 0.64±0.35 vs. 0.93±0.30, LDL-C (mmol/L): 1.32±0.64 vs. 2.08±0.94, TC (mmol/L): 1.39 (1.01, 2.23) vs. 2.69 (1.72, 3.81), all P < 0.01]. With the progression of the disease, the PCSK9 in the sepsis death group and the survival group was significantly lower than that within 1 day of diagnosis (all P < 0.05). ROC curve analysis showed that PCSK9 had higher predictive value of 28-day death than HDL-C, LDL-C, TC [area under ROC curve (AUC) and 95% confidence interval (95% CI): 0.748 (0.611-0.885) vs. 0.710 (0.552-0.868), 0.721 (0.575-0.867), 0.702 (0.550-0.854)]. Multivariate Logistic regression analysis showed that PCSK9 was an independent risk factor affecting the 28-day prognosis of sepsis (β value was 1.014, P = 0.020). Kaplan-Meier survival curve analysis showed that when PCSK9 ≥ 208.97 μg/L, with the increase of PCSK9, the 28-day survival rate of sepsis patients decreased significantly. Conclusions:PCSK9, HDL-C, LDL-C and TC can all predict the 28-day prognosis of patients with sepsis. The prognostic value of PCSK9 is the highest. PCSK9 is an independent risk factor affecting the prognosis of sepsis. In the early stage of the disease, PCSK9 may have a good predictive value for the prognosis of sepsis. When PCSK9 ≥ 208.97 μg/L, the 28-day survival rate decreased significantly.

Characteristics of obstructive sleep apnea in children with allergic rhinitis / 中国小儿急救医学

Objective:To analyze the characteristics of sleep disordered breathing (SDB) in children with allergic rhinitis (AR), and improve the diagnosis and treatment at AR combined with obstructive sleep apnea (OSA).Methods:The clinical data of 120 patients with AR and OSA (AR and OSA group) admitted to the respiratory department at Shenzhen Children′s Hospital from May 2019 to December 2020 were retrospectively analyzed.A total of 120 children diagnosed with OSA and excluded AR during the same period were selected as control group.The SDB day and night symptoms, sleep structure characteristics and sleep breathing events were compared between two groups.Results:The average course of disease in children with AR and OSA was significantly longer than that in control group ( P=0.030). The main manifestations of children in AR and OSA group were mouth breathing (100.0%), snoring (99.2%), nasal obstruction (88.5%), and restless sleep (68.0%). There was no significant difference in sleep structure between two groups ( P>0.05), but the sleep efficiency of AR and OSA group was significantly lower than that of control group ( P=0.028). The respiratory events apnea hypopnea index, obstructive apnea index, obstructive apnea hypopnea index, hypopnea index and oxygen desaturation index of each sleep period in AR and OSA group were significantly higher than those in control group ( P<0.05). Among the children in AR and OSA group, moderate and severe OSA were the main manifestations, and the difference between two groups was statistically significant ( P<0.001). Conclusion:The combination of AR delayed the course of OSA in children.The main characteristics of sleep disordered breathing in children with AR are mouth opening, restless sleep, snoring and nasal obstruction.The sleep efficiency is decreased.Obstructive hypopnea and apnea are the most common respiratory events, and oxygen deficiency often occurs in rapid eye movement phase.Children with AR are more likely to have moderate or severe obstructive sleep apnea.

IRF4 and IRF8 expression are associated with clinical phenotype and clinico-hematological response to hydroxyurea in essential thrombocythemia / 医学前沿

The morbidity and mortality of myeloproliferative neoplasms (MPNs) are primarily caused by arterial and venous complications, progression to myelofibrosis, and transformation to acute leukemia. However, identifying molecular-based biomarkers for risk stratification of patients with MPNs remains a challenge. We have previously shown that interferon regulatory factor-8 (IRF8) and IRF4 serve as tumor suppressors in myeloid cells. In this study, we evaluated the expression of IRF4 and IRF8 and the JAK2V617F mutant allele burden in patients with MPNs. Patients with decreased IRF4 expression were correlated with a more developed MPN phenotype in myelofibrosis (MF) and secondary AML (sAML) transformed from MPNs versus essential thrombocythemia (ET). Negative correlations between the JAK2V617F allele burden and the expression of IRF8 (P < 0.05) and IRF4 (P < 0.001) and between white blood cell (WBC) count and IRF4 expression (P < 0.05) were found in ET patients. IRF8 expression was negatively correlated with the JAK2V617F allele burden (P < 0.05) in polycythemia vera patients. Complete response (CR), partial response (PR), and no response (NR) were observed in 67.5%,10%, and 22.5% of ET patients treated with hydroxyurea (HU), respectively, in 12 months. At 3 months, patients in the CR group showed high IRF4 and IRF8 expression compared with patients in the PR and NR groups. In the 12-month therapy period, low IRF4 and IRF8 expression were independently associated with the unfavorable response to HU and high WBC count. Our data indicate that the expression of IRF4 and IRF8 was associated with the MPN phenotype, which may serve as biomarkers for the response to HU in ET.