Mining of high throughput screening database reveals AP-1 and autophagy pathways as potential targets for COVID-19 therapeutics

The recent global pandemic of the Coronavirus disease 2019 (COVID-19) caused by the new coronavirus SARS-CoV-2 presents an urgent need for the development of new therapeutic candidates. Many efforts have been devoted to screening existing drug libraries with the hope to repurpose approved drugs as potential treatments for COVID-19. However, the antiviral mechanisms of action of the drugs found active in these phenotypic screens remain largely unknown. In an effort to deconvolute the viral targets in pursuit of more effective anti-COVID-19 drug development, we mined our in-house database of approved drug screens against 994 assays and compared their activity profiles with the drug activity profile in a cytopathic effect (CPE) assay of SARS-CoV-2. We found that the autophagy and AP-1 signaling pathway activity profiles are significantly correlated with the anti-SARS-CoV-2 activity profile. In addition, a class of neurology/psychiatry drugs was found to be significantly enriched with anti-SARS-CoV-2 activity. Taken together, these results provide new insights into SARS-CoV-2 infection and potential targets for COVID-19 therapeutics, which can be further validated by in vivo animal studies and human clinical trials.

Application of niclosamide and analogs as small molecule inhibitors of Zika virus and SARS-CoV-2 infection

Zika virus has emerged as a potential threat to human health globally. A previous drug repurposing screen identified the approved anthelminthic drug niclosamide as a small molecule inhibitor of Zika virus infection. However, as antihelminthic drugs are generally designed to have low absorption when dosed orally, the very limited bioavailability of niclosamide will likely hinder its potential direct repurposing as an antiviral medication. Here, we conducted SAR studies focusing on the anilide and salicylic acid regions of niclosamide to improve physicochemical properties such as microsomal metabolic stability, permeability and solubility. We found that the 5-bromo substitution in the salicylic acid region retains potency while providing better drug-like properties. Other modifications in the anilide region with 2′-OMe and 2′-H substitutions were also advantageous. We found that the 4′-NO₂ substituent can be replaced with a 4′-CN or 4′-CF₃ substituents. Together, these modifications provide a basis for optimizing the structure of niclosamide to improve systemic exposure for application of niclosamide analogs as drug lead candidates for treating Zika and other viral infections. Indeed, key analogs were also able to rescue cells from the cytopathic effect of SARS-CoV-2 infection, indicating relevance for therapeutic strategies targeting the COVID-19 pandemic.

A205 PEMBROLIZUMAB ASSOCIATED SCLEROSING CHOLANGITIS RESPONDS TO COMBINATION OF STEROIDS AND MYCOPHENOLIC ACID: A CASE REPORT

Background

Pembrolizumab is a check point inhibitor that targets programmed cell death receptor ligand 1 (PD-L1). However, check-point inhibitors are associated with its characteristic adverse event know as immune related adverse events that can affect a myriad of organ systems. In the hepatobiliary system, the most commonly described iRAE is hepatitis/hepatotoxicity and latest oncology guidelines offer recommendations on treatment and followup of immunotherapy related hepatitis (1). However, a more rare presentation of iRAE, that have only been described as case reports or case series, is secondary cholangitis. We report one of such a case.

Aims

Case report

Methods

Case report

Results

The patient is a 55 year-old Caucasian female know for lung adenocarcinoma presented to the emergency room on May 5th, 2020, having received her 8th cycle of pembrolizumab. Her blood works mildly elevated transaminitis; ALT 78 U/L, AST 11 U/L, alkaline phosphate of 130 U/L, and total bilirubin of 3.5 umol/L.

MRI of the abdomen showed a normal appearing liver without focal parenchymal lesion, no biliary stones or obstructing masses, dilated common bile duct at 11 mm with small pericholecystic free fluid, and normal gall badder thickness of 2 mm. There was also notion of minimally prominent intrahepatic biliary radicles seen within the CBD.

Etiology workup of cholestatic transaminitis was negative. A diagnosis of immunotherapy related sclerosing cholangitis was posed and the patient was treated with MMF and prednisone with good response.

Conclusions

Discussion

This patient seems to have developed immunotherapy mediated cholangitis. Liver biopsy when performed in liver injury tend to show lobular hepatitis, with liver parenchyma infiltrated with lymphocytes and focal necrosis with acidophilic bodies. However, there seems to be another, less frequent pattern of injury described with pembrolizumab and associated with cholangiopathy, resembling primary biliary cholangitis. It is characterized with portal tracts enlarged with fibrosis and inflammatory cells infiltration; infiltrating cells are lymphocytes (2). Biliary epithelium with fibrosis with CD8+ T cells infiltration seem to be recurrently reported in case reports. (3, 4).

Other cases have been describe in the literature. In many cases, steroid therapy was attempted, but response rates seem to be inconsistent. Nivolumab related cholangitis have been also been described and characterized by extra hepatic bile duct dilatation along with negative immunological markers such as ANA and IgG4 in patients with non-small cell lung cancer, and seems to respond only moderately to steroid therapy (6). Retrospective data of nivolumab related cholangiopathy seems to suggest that there is favourable response to the combination of MMF and steroid therapy (7).

Funding Agencies

None

Utility of Contrast-Enhanced T2 FLAIR for Imaging Brain Metastases Using a Half-dose High-Relaxivity Contrast Agent

BACKGROUND AND PURPOSE

Efficient detection of metastases is important for patient' treatment. This prospective study was to explore the clinical value of contrast-enhanced T2 FLAIR in imaging brain metastases using half-dose gadobenate dimeglumine.

MATERIALS AND METHODS

In vitro signal intensity of various gadolinium concentrations was explored by spin-echo T1-weighted imaging and T2 FLAIR. Then, 46 patients with lung cancer underwent nonenhanced T2 FLAIR before administration of half-dose gadobenate dimeglumine and 3 consecutive contrast-enhanced T2 FLAIR sequences followed by 1 spin-echo T1WI after administration of half-dose gadobenate dimeglumine. After an additional dose of 0.05 mmol/kg, 3D brain volume imaging was performed. All brain metastases were classified as follows: solid-enhancing, ≥ 5 mm (group A); ring-enhancing, ≥ 5 mm (group B); and lesion diameter of <5 mm (group C). The contrast ratio of the lesions on 3 consecutive phases of contrast-enhanced T2 FLAIR was measured, and the percentage increase of contrast-enhanced T2 FLAIR among the 3 groups was compared.

RESULTS

In vitro, the maximal signal intensity was achieved in T2 FLAIR at one-eighth to one-half of the contrast concentration needed for maximal signal intensity in T1WI. In vivo, the mean contrast ratio values of metastases on contrast-enhanced T2 FLAIR for the 3 consecutive phases ranged from 63.64% to 83.05%. The percentage increase (PI) values of contrast-enhanced T2 FLAIR were as follows: PI_A < PI_B (P = .001) and PI_A < PI_C (P < .001). The degree of enhancement of brain metastases on contrast-enhanced T2 FLAIR was lower than on 3D brain volume imaging (P < .001) in group A, and higher than on 3D brain volume imaging (P < .001) in group C.

CONCLUSIONS

Small or ring-enhancing metastases can be better visualized on delayed contrast-enhanced T2 FLAIR using a half-dose high-relaxivity contrast agent.

The Tox21 10K Compound Library: Collaborative Chemistry Advancing Toxicology

Since 2009, the Tox21 project has screened ∼8500 chemicals in more than 70 high-throughput assays, generating upward of 100 million data points, with all data publicly available through partner websites at the United States Environmental Protection Agency (EPA), National Center for Advancing Translational Sciences (NCATS), and National Toxicology Program (NTP). Underpinning this public effort is the largest compound library ever constructed specifically for improving understanding of the chemical basis of toxicity across research and regulatory domains. Each Tox21 federal partner brought specialized resources and capabilities to the partnership, including three approximately equal-sized compound libraries. All Tox21 data generated to date have resulted from a confluence of ideas, technologies, and expertise used to design, screen, and analyze the Tox21 10K library. The different programmatic objectives of the partners led to three distinct, overlapping compound libraries that, when combined, not only covered a diversity of chemical structures, use-categories, and properties but also incorporated many types of compound replicates. The history of development of the Tox21 "10K" chemical library and data workflows implemented to ensure quality chemical annotations and allow for various reproducibility assessments are described. Cheminformatics profiling demonstrates how the three partner libraries complement one another to expand the reach of each individual library, as reflected in coverage of regulatory lists, predicted toxicity end points, and physicochemical properties. ToxPrint chemotypes (CTs) and enrichment approaches further demonstrate how the combined partner libraries amplify structure-activity patterns that would otherwise not be detected. Finally, CT enrichments are used to probe global patterns of activity in combined ToxCast and Tox21 activity data sets relative to test-set size and chemical versus biological end point diversity, illustrating the power of CT approaches to discern patterns in chemical-activity data sets. These results support a central premise of the Tox21 program: A collaborative merging of programmatically distinct compound libraries would yield greater rewards than could be achieved separately.

The Tox21 10K Compound Library: Collaborative Chemistry Advancing Toxicology

Since 2009, the Tox21 project has screened ∼8500 chemicals in more than 70 high-throughput assays, generating upward of 100 million data points, with all data publicly available through partner websites at the United States Environmental Protection Agency (EPA), National Center for Advancing Translational Sciences (NCATS), and National Toxicology Program (NTP). Underpinning this public effort is the largest compound library ever constructed specifically for improving understanding of the chemical basis of toxicity across research and regulatory domains. Each Tox21 federal partner brought specialized resources and capabilities to the partnership, including three approximately equal-sized compound libraries. All Tox21 data generated to date have resulted from a confluence of ideas, technologies, and expertise used to design, screen, and analyze the Tox21 10K library. The different programmatic objectives of the partners led to three distinct, overlapping compound libraries that, when combined, not only covered a diversity of chemical structures, use-categories, and properties but also incorporated many types of compound replicates. The history of development of the Tox21 "10K" chemical library and data workflows implemented to ensure quality chemical annotations and allow for various reproducibility assessments are described. Cheminformatics profiling demonstrates how the three partner libraries complement one another to expand the reach of each individual library, as reflected in coverage of regulatory lists, predicted toxicity end points, and physicochemical properties. ToxPrint chemotypes (CTs) and enrichment approaches further demonstrate how the combined partner libraries amplify structure-activity patterns that would otherwise not be detected. Finally, CT enrichments are used to probe global patterns of activity in combined ToxCast and Tox21 activity data sets relative to test-set size and chemical versus biological end point diversity, illustrating the power of CT approaches to discern patterns in chemical-activity data sets. These results support a central premise of the Tox21 program: A collaborative merging of programmatically distinct compound libraries would yield greater rewards than could be achieved separately.

Deep Graph Learning with Property Augmentation for Predicting Drug-Induced Liver Injury

Drug-induced liver injury (DILI) is a crucial factor in determining the qualification of potential drugs. However, the DILI property is excessively difficult to obtain due to the complex testing process. Consequently, an in silico screening in the early stage of drug discovery would help to reduce the total development cost by filtering those drug candidates with a high risk to cause DILI. To serve the screening goal, we apply several computational techniques to predict the DILI property, including traditional machine learning methods and graph-based deep learning techniques. While deep learning models require large training data to tune huge model parameters, the DILI data set only contains a few hundred annotated molecules. To alleviate the data scarcity problem, we propose a property augmentation strategy to include massive training data with other property information. Extensive experiments demonstrate that our proposed method significantly outperforms all existing baselines on the DILI data set by obtaining a 81.4% accuracy using cross-validation with random splitting, 78.7% using leave-one-out cross-validation, and 76.5% using cross-validation with scaffold splitting.

An Integrated Systems Biology Approach Identifies the Proteasome as A Critical Host Machinery for ZIKV and DENV Replication

The Zika virus (ZIKV) and dengue virus (DENV) flaviviruses exhibit similar replicative processes but have distinct clinical outcomes. A systematic understanding of virus-host protein-protein interaction networks can reveal cellular pathways critical to viral replication and disease pathogenesis. Here we employed three independent systems biology approaches toward this goal. First, protein array analysis of direct interactions between individual ZIKV/DENV viral proteins and 20,240 human proteins revealed multiple conserved cellular pathways and protein complexes, including proteasome complexes. Second, an RNAi screen of 10,415 druggable genes identified the host proteins required for ZIKV infection and uncovered that proteasome proteins were crucial in this process. Third, high-throughput screening of 6016 bioactive compounds for ZIKV inhibition yielded 134 effective compounds, including six proteasome inhibitors that suppress both ZIKV and DENV replication. Integrative analyses of these orthogonal datasets pinpoint proteasomes as critical host machinery for ZIKV/DENV replication. Our study provides multi-omics datasets for further studies of flavivirus-host interactions, disease pathogenesis, and new drug targets.

Trade-off Predictivity and Explainability for Machine-Learning Powered Predictive Toxicology: An in-Depth Investigation with Tox21 Data Sets

Selecting a model in predictive toxicology often involves a trade-off between prediction performance and explainability: should we sacrifice the model performance to gain explainability or vice versa. Here we present a comprehensive study to assess algorithm and feature influences on model performance in chemical toxicity research. We conducted over 5000 models for a Tox21 bioassay data set of 65 assays and ∼7600 compounds. Seven molecular representations as features and 12 modeling approaches varying in complexity and explainability were employed to systematically investigate the impact of various factors on model performance and explainability. We demonstrated that end points dictated a model's performance, regardless of the chosen modeling approach including deep learning and chemical features. Overall, more complex models such as (LS-)SVM and Random Forest performed marginally better than simpler models such as linear regression and KNN in the presented Tox21 data analysis. Since a simpler model with acceptable performance often also is easy to interpret for the Tox21 data set, it clearly was the preferred choice due to its better explainability. Given that each data set had its own error structure both for dependent and independent variables, we strongly recommend that it is important to conduct a systematic study with a broad range of model complexity and feature explainability to identify model balancing its predictivity and explainability.

Evaluation of chemical compounds that inhibit neurite outgrowth using GFP-labeled iPSC-derived human neurons

Due to the increasing number of drugs and untested environmental compounds introduced into commercial use, there is recognition for a need to develop reliable and efficient screening methods to identify compounds that may adversely impact the nervous system. One process that has been implicated in neurodevelopment is neurite outgrowth; the disruption of which can result in adverse outcomes that persist later in life. Here, we developed a green fluorescent protein (GFP) labeled neurite outgrowth assay in a high-content, high-throughput format using induced pluripotent stem cell (iPSC) derived human spinal motor neurons and cortical glutamatergic neurons. The assay was optimized for use in a 1536-well plate format. Then, we used this assay to screen a set of 84 unique compounds that have previously been screened in other neurite outgrowth assays. This library consists of known developmental neurotoxicants, environmental compounds with unknown toxicity, and negative controls. Neurons were cultured for 40 h and then treated with compounds at 11 concentrations ranging from 1.56 nM to 92 μM for 24 and 48 h. Effects of compounds on neurite outgrowth were evaluated by quantifying total neurite length, number of segments, and maximum neurite length per cell. Among the 84 tested compounds, neurite outgrowth in cortical neurons and motor neurons were selectively inhibited by 36 and 31 compounds, respectively. Colchicine, rotenone, and methyl mercuric (II) chloride inhibited neurite outgrowth in both cortical and motor neurons. It is interesting to note that some compounds like parathion and bisphenol AF had inhibitory effects on neurite outgrowth specifically in the cortical neurons, while other compounds, such as 2,2',4,4'-tetrabromodiphenyl ether and caffeine, inhibited neurite outgrowth in motor neurons. The data gathered from these studies show that GFP-labeled iPSC-derived human neurons are a promising tool for identifying and prioritizing compounds with developmental neurotoxicity potential for further hazard characterization.

Drug Repurposing Screen for Compounds Inhibiting the Cytopathic Effect of SARS-CoV-2

Drug repurposing is a rapid approach to identify therapeutics for the treatment of emerging infectious diseases such as COVID-19. To address the urgent need for treatment options, we carried out a quantitative high-throughput screen using a SARS-CoV-2 cytopathic assay with a compound collection of 8,810 approved and investigational drugs, mechanism-based bioactive compounds, and natural products. Three hundred and nineteen compounds with anti-SARS-CoV-2 activities were identified and confirmed, including 91 approved drugs and 49 investigational drugs. The anti-SARS-CoV-2 activities of 230 of these confirmed compounds, of which 38 are approved drugs, have not been previously reported. Chlorprothixene, methotrimeprazine, and piperacetazine were the three most potent FDA-approved drugs with anti-SARS-CoV-2 activities. These three compounds have not been previously reported to have anti-SARS-CoV-2 activities, although their antiviral activities against SARS-CoV and Ebola virus have been reported. These results demonstrate that this comprehensive data set is a useful resource for drug repurposing efforts, including design of new drug combinations for clinical trials for SARS-CoV-2.

Spinal schwannoma causes acute subarachnoid haemorrhage: A case report and literature review

BACKGROUND

Spinal schwannomas that arise from spinal nerve root sheaths are the most common intradural extramedullary spinal tumours and are often accompanied by nerve roots or spinal cord irritation symptoms. The phenomenon of spinal schwannoma causing subarachnoid haemorrhage (SAH) is rare, with ependymoma of the conus medullaris accounting for most cases.

CASE REPORT

A 45-year-old man was admitted to our hospital due to progressive lower limb weakness and sudden back pain after hard physical work. The patient had not been able to walk for 2hours upon admission. An emergency magnetic resonance imaging (MRI) scan showed that the spinal cord at the C6-T4 level was severely compressed by a subdural mass. During the emergency operation, exploration of the dura and arachnoid mater revealed a fresh blood clot covering a tumour located on the ventral side of the spinal cord. The size of the tumour was approximately 3×2×1cm without adhesion to the surrounding tissue, but the drainage vein was ruptured. Postoperative pathology showed that the tumour was a schwannoma with areas of fresh haemorrhage and focal necrosis.

CONCLUSIONS

Spinal schwannomas presenting with SAH are rare events. In our opinion, spinal pathology with rapid progression of neurological symptoms requires early diagnosis and emergency management. Complete excision of haemorrhagic tumours is the goal of treatment to prevent recurrence, which can effectively avoid irreversible damage to the spinal cord resulting from spinal cord compression.

Systematic Identification of Molecular Targets and Pathways Related to Human Organ Level Toxicity

The mechanisms leading to organ level toxicities are poorly understood. In this study, we applied an integrated approach to deduce the molecular targets and biological pathways involved in chemically induced toxicity for eight common human organ level toxicity end points (carcinogenicity, cardiotoxicity, developmental toxicity, hepatotoxicity, nephrotoxicity, neurotoxicity, reproductive toxicity, and skin toxicity). Integrated analysis of in vitro assay data, molecular targets and pathway annotations from the literature, and toxicity-molecular target associations derived from text mining, combined with machine learning techniques, were used to generate molecular targets for each of the organ level toxicity end points. A total of 1516 toxicity-related genes were identified and subsequently analyzed for biological pathway coverage, resulting in 206 significant pathways (p-value <0.05), ranging from 3 (e.g., developmental toxicity) to 101 (e.g., skin toxicity) for each toxicity end point. This study presents a systematic and comprehensive analysis of molecular targets and pathways related to various in vivo toxicity end points. These molecular targets and pathways could aid in understanding the biological mechanisms of toxicity and serve as a guide for the design of suitable in vitro assays for more efficient toxicity testing. In addition, these results are complementary to the existing adverse outcome pathway (AOP) framework and can be used to aid in the development of novel AOPs. Our results provide abundant testable hypotheses for further experimental validation.

[Research frontiers in precision therapy for liver cancer]

Hepatocellular carcinoma (HCC), a fatal malignancy, is highly prevalent in China. Recently, tremendous achievements have been made in HCC, both in the clinical management and the understanding of cancer biology. The discovery and application of novel serum biomarkers, such as proteins, miRNAs, and cfDNA (cell-free circulating DNA) methylation will facilitate the early management of HCC. Improvements in radiological and computational technology have made the practice of precision liver surgery a true reality. The emergence of novel molecular targeted therapies, immunotherapy and their combinations has significantly prolonged patient survival rate, but the therapeutic breakthroughs are still needed. Integrated multi-omics analysis has broadened our understanding of HCC pathogenesis, providing an unprecedented molecular characterization of HCC and revealing new therapeutic opportunities. Technological innovations and revolutions such as single-cell sequencing, genome editing, and innovative drug research and development will greatly accelerate our understanding of HCC biology and bring new therapeutic opportunities. Nevertheless, HCC is a highly heterogeneous and treatment-refractory malignancy, therefore deep insights into the biology of the disease and novel therapies for HCC remain an unmet medical need.

Conversion and outcome of dual antiplatelet therapy after bleeding in patients with acute coronary syndrome

Objective

To explore the conversion and outcome of antiplatelet therapy in patients with acute coronary syndrome (ACS) who have suffered bleeding after receiving aspirin combined with ticagrelor.

Methods

Patients who diagnosed with ACS and given aspirin 100 mg once daily combined with ticagrelor 90 mg twice daily for dual antiplatelet therapy (DAPT) were selected. The patients were divided into bleeding group and non-bleeding group according to whether bleeding events occurred within one year after DAPT. The bleeding group was divided into the next four groups according to the converted antiplatelet treatment strategy decided by the doctor and the patient. Patients in group A to D were treated with ticagrelor 90mg twice a day plus aspirin 0–50mgonce a day, ticagrelor 60mg twice a day plus aspirin 100mgonce a day, clopidogrel 75mgonce a day plus aspirin 100mg once a day and ticagrelor 90mg twice a day plus aspirin 100mg once a day, respectively. All patients were followed up for 1 year after DAPT. The primary outcome is change of bleeding degree by BARC. The secondary outcomes includes BARC bleeding, all-cause mortality and MACE.

Results

A total of 752 cases were enrolled, including 250 in the bleeding group and 502 in the non-bleeding group. The bleeding group was divided into four treatment groups, which were 63, 43, 38 and 95 cases among A, B, C and D group. There was a significant difference in the improvement of bleeding among the four groups. To be noted, patients in group A has the highest improvement rate of hemorrhage (65.1% vs 62.8% vs 47.4% vs 24.2%, P&lt;0.01). There were no significant differences in the incidence of MACE and all-cause mortality (P&gt;0.05). The incidence of major MACE in patients in the bleeding group was 14.4%, which was higher than that in the non-bleeding group (9.2%, P=0.03).The result of multivariate logistic regression analysis showed that female (OR=5.18, 95% CI: 1.61–16.65, P=0.006), low body weight (OR=7.73, 95% CI: 2.46–24.49, P&lt;0.001) and low AA-induced maximum platelet aggregation rate (OR=2.72, 95% CI:1.09–6.84, P=0.033) were independent risk factors for hemorrhage.

Conclusion

Patients with acute coronary syndrome who have suffered bleeding after receiving aspirin combined with ticagrelor were at a higher risk of MACE than those who did not. Low-dose aspirin (0–50mg/d) combined with ticagrelor or even ticagrelor alone has the best effect on reducing bleeding without increasing the risk of ischemia. Female, low body mass and low AA-induced maximum platelet aggregation rate are independent risk factors for bleeding.

Funding Acknowledgement

Type of funding source: None

[Perceived organizational support and emotional stability modify the effect of depression tendency on burnout in doctors]

Objective: To explore and analyze the relationship between burnout, depression, perceived organizational support and emotional stability, as well as their interaction on burnout, so as to provide reference for improving the situation of burnout on doctors. Methods: By cluster random sampling, a cross-sectional survey of doctors in a municipal hospitals of Zhengzhou in June to August, 2015, Henan Province was conducted. The questionnaires of Maslach Burnout Inventory-General Survey (MBI-GS) , Perceived organizational support, Eysenck Personality Questionnair-Revission Short Scale of China (EPQ-RSC) and Center for Epidemiological Studies Depression Scale (CES-D) were used for questionnaire survey and analysis. Multiple regression analysis was used to explore the interaction of organizational support and emotional stability on depressive tendency and occupational burnout. Results: Among the 389 doctors, 147 were males and 242 were females. Age M (P(25), P(75)) was 33.0 (29.0, 40.0) years, and length of work M (P(25), P(75)) was 7.0 (4.0, 16.0) years. Burnout was positively correlated with depression tendency and emotional stability (r=0.571, 0.453, P<0.01) , while burnout was negatively correlated with perceived organizational support (r=-0.260, P<0.01) . The interaction among depression tendency, perceived organizational support and emotional stability was statistically significant (β=-0.002, P<0.05) , the independent effect on burnout is 1.0% (ΔR(2)=0.010) , the positive effect of emotional stability was the largest (β=0.550) , followed by the positive effect of depression tendency (β=0.494) . When the tendency of depression increased, the burnout of doctors with high perceived organizational support and emotional stability was higher than those with high perceived organizational support and emotional instability and those with low perceived organizational support (P<0.01) . Conclusion: Emotional stability is the main factor affecting the effect of depression tendency on doctors' burnout. Doctors with stable emotion and high perceived organizational support showed obvious changes in burnout when depression tendency increased, and showed stronger burnout.

Methylene blue is a potent and broad-spectrum inhibitor against Zika virus in vitro and in vivo

Many flaviviruses including the Dengue virus (DENV), Zika virus (ZIKV), West Nile virus, Yellow Fever virus, and Japanese encephalitis virus are significant human pathogens, unfortunately without any specific therapy. Here, we demonstrate that methylene blue, an FDA-approved drug, is a broad-spectrum and potent antiviral against Zika virus and Dengue virus both in vitro and in vivo. We found that methylene blue can considerably inhibit the interactions between viral protease NS3 and its NS2B co-factor, inhibit viral protease activity, inhibit viral growth, protect 3D mini-brain organoids from ZIKV infection, and reduce viremia in a mouse model. Mechanistic studies confirmed that methylene blue works in both entry and post entry steps, reduces virus production in replicon cells and inhibited production of processed NS3 protein. Overall, we have shown that methylene blue is a potent antiviral for management of flavivirus infections, particularly for Zika virus. As an FDA-approved drug, methylene blue is well-tolerated for human use. Therefore, methylene blue represents a promising and easily developed therapy for management of infections by ZIKV and other flaviviruses.

XIST lost induces ovarian cancer stem cells to acquire taxol resistance via a KMT2C-dependent way

BACKGROUND/AIMS

The expression levels of long non-coding RNA XIST are significantly associated with paclitaxel (Pac) sensitivity in ovarian cancer, but the mechanism of action remains unclear. Therefore, this experimental design was based on lncRNA XIST analysis to regulate the effect of XIST on the tumor stem cell and paclitaxel sensitivity in ovarian cancer.

METHODS

Sphere assay and fluorescence activated cell sorting (FACS) were used to determine the expression levels of XIST and sensitivity to paclitaxel treatment. The effect of the proliferation was detected by MTT assay. Target gene prediction and screening, luciferase reporter assays were used to validate downstream target genes for lncRNA XIS and KMT2C. The expression of KMT2C was detected by RT-qPCR and Western blotting. RT-qPCR was used to detect the expression of cancer stem cell-associated genes SOX2, OCT4 and Nanog. The tumor changes in mice were detected by in vivo experiments in nude mice.

RESULTS

There was an inverse correlation between the expression of XIST and cancer stem cell (CD44 + /CD24-) population. XIST promoted methylation of histone H3 methylation at lysine 4 by enhancing the stability of lysine (K)-specific methyltransferase 2C (KMT2C) mRNA. XIST acted on the stability of KMT2C mRNA by directly targeting miR-93-5p. Overexpression of miR-93-5p can reverse the XIST overexpression-induced KMT2C decrease and sphere number increase. Overexpression of KMT2C inhibited XIST silencing-induced proliferation of cancer stem cells, and KMT2C was able to mediate paclitaxel resistance induced by XIST in ovarian cancer. The study found that XIST can affect the expression of KMT2C in the ovarian cancer via targeting miR-93-5p.

CONCLUSION

XIST promoted the sensitivity of ovarian cancer stem cells to paclitaxel in a KMT2C-dependent manner.