Transverse-momentum and pseudorapidity distributions of charged hadrons in pp collisions at √s=0.9 and 2.36 TeV

Measurements of inclusive charged-hadron transverse-momentum and pseudorapidity distributions are presented for proton-proton collisions at root s = 0.9 and 2.36 TeV. The data were collected with the CMS detector during the LHC commissioning in December 2009. For non-single-diffractive interactions, the average charged-hadron transverse momentum is measured to be 0.46 +/- 0.01 (stat.) +/- 0.01 (syst.) GeV/c at 0.9 TeV and 0.50 +/- 0.01 (stat.) +/- 0.01 (syst.) GeV/c at 2.36 TeV, for pseudorapidities between -2.4 and +2.4. At these energies, the measured pseudorapidity densities in the central region, dN(ch)/d eta vertical bar(vertical bar eta vertical bar and pp collisions. The results at 2.36 TeV represent the highest-energy measurements at a particle collider to date

Involvement of oxidative stress and calcium signaling in airborne particulate matter - induced damages in human pulmonary artery endothelial cells

International audienceRecent studies have revealed that particulate matter (PM) exert deleterious effects on vascular function. Pulmonary artery endothelial cells (HPAEC), which are involved in the vasomotricity regulation, can be a direct target of inhaled particles. Modifications in calcium homeostasis and oxidative stress are critical events involved in the physiopathology of vascular diseases. The objectives of this study were to assess the effects of PM2.5 on oxidative stress and calcium signaling in HPAEC. Different endpoints were studied, (i) intrinsic and intracellular production of reactive oxygen species (ROS) by the H2DCF-DA probe, (ii) intrinsic, intracellular and mitochondrial production of superoxide anion (O2radical dot−) by electronic paramagnetic resonance spectroscopy and MitoSOX probe, (iii) reactive nitrosative species (RNS) production by Griess reaction, and (vi) calcium signaling by the Fluo-4 probe. In acellular conditions, PM2.5 leads to an intrinsic free radical production (ROS, O2radical dot−) and a 4 h-exposure to PM2.5 (5–15 μg/cm2), induced, in HPAEC, an increase of RNS, of global ROS and of cytoplasmic and mitochondrial O2radical dot− levels. The basal intracellular calcium ion level [Ca2 +]i was also increased after 4 h-exposure to PM2.5 and a pre-treatment with superoxide dismutase and catalase significantly reduced this response. This study provides evidence that the alteration of intracellular calcium homeostasis induced by PM2.5 is closely correlated to an increase of oxidative stress

DYRK1A promotes viral entry of highly pathogenic human coronaviruses in a kinase-independent manner

Identifying host genes essential for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has the potential to reveal novel drug targets and further our understanding of Coronavirus Disease 2019 (COVID-19). We previously performed a genome-wide CRISPR/Cas9 screen to identify proviral host factors for highly pathogenic human coronaviruses. Few host factors were required by diverse coronaviruses across multiple cell types, but DYRK1A was one such exception. Although its role in coronavirus infection was previously undescribed, DYRK1A encodes Dual Specificity Tyrosine Phosphorylation Regulated Kinase 1A and is known to regulate cell proliferation and neuronal development. Here, we demonstrate that DYRK1A regulates ACE2 and DPP4 transcription independent of its catalytic kinase function to support SARS-CoV, SARS-CoV-2, and Middle East Respiratory Syndrome Coronavirus (MERS-CoV) entry. We show that DYRK1A promotes DNA accessibility at the ACE2 promoter and a putative distal enhancer, facilitating transcription and gene expression. Finally, we validate that the proviral activity of DYRK1A is conserved across species using cells of nonhuman primate and human origin. In summary, we report that DYRK1A is a novel regulator of ACE2 and DPP4 expression that may dictate susceptibility to multiple highly pathogenic human coronaviruses

DYRK1A promotes viral entry of highly pathogenic human coronaviruses in a kinase-independent manner.

Identifying host genes essential for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has the potential to reveal novel drug targets and further our understanding of Coronavirus Disease 2019 (COVID-19). We previously performed a genome-wide CRISPR/Cas9 screen to identify proviral host factors for highly pathogenic human coronaviruses. Few host factors were required by diverse coronaviruses across multiple cell types, but DYRK1A was one such exception. Although its role in coronavirus infection was previously undescribed, DYRK1A encodes Dual Specificity Tyrosine Phosphorylation Regulated Kinase 1A and is known to regulate cell proliferation and neuronal development. Here, we demonstrate that DYRK1A regulates ACE2 and DPP4 transcription independent of its catalytic kinase function to support SARS-CoV, SARS-CoV-2, and Middle East Respiratory Syndrome Coronavirus (MERS-CoV) entry. We show that DYRK1A promotes DNA accessibility at the ACE2 promoter and a putative distal enhancer, facilitating transcription and gene expression. Finally, we validate that the proviral activity of DYRK1A is conserved across species using cells of nonhuman primate and human origin. In summary, we report that DYRK1A is a novel regulator of ACE2 and DPP4 expression that may dictate susceptibility to multiple highly pathogenic human coronaviruses

Bidirectional genome-wide CRISPR screens reveal host factors regulating SARS-CoV-2, MERS-CoV and seasonal HCoVs

International audienceCRISPR knockout (KO) screens have identified host factors regulating severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication. Here, we conducted a meta-analysis of these screens, which showed a high level of cell-type specificity of the identified hits, highlighting the necessity of additional models to uncover the full landscape of host factors. Thus, we performed genome-wide KO and activation screens in Calu-3 lung cells and KO screens in Caco-2 colorectal cells, followed by secondary screens in four human cell lines. This revealed host-dependency factors, including AP1G1 adaptin and ATP8B1 flippase, as well as inhibitors, including mucins. Interestingly, some of the identified genes also modulate Middle East respiratory syndrome coronavirus (MERS-CoV) and seasonal human coronavirus (HCoV) (HCoV-NL63 and HCoV-229E) replication. Moreover, most genes had an impact on viral entry, with AP1G1 likely regulating TMPRSS2 activity at the plasma membrane. These results demonstrate the value of multiple cell models and perturbational modalities for understanding SARS-CoV-2 replication and provide a list of potential targets for therapeutic interventions

DYRK1A and SMARCA4 share limited similarities in regulating chromatin accessibility and gene expression.

(A) Principal component analysis of ATAC-Seq experiments performed in DYRK1A KO+vec, DYRK1A KO+WT, SMARCA4 KO+vec, and SMARCA4 KO+WT cells generated in a parental Vero-E6 background. Each experiment was performed in biological duplicate (replicates 1 and 2). DYRK1A and SMARCA4 loss share some molecular impacts, suggesting that some pathways may be coregulated (PC1), whereas others may be independently regulated (PC2). (B) Correlation heatmap comparing all sites from ATAC-Seq experiments in DYRK1A KO+vec, DYRK1A KO+WT, SMARCA4 KO+vec, and SMARCA4 KO+WT cells. (C) Correlation heatmap comparing chromatin accessibility by ATAC-Seq in DYRK1A or SMARCA4 complemented cells, identifying a correlation coefficient of 0.33 supporting approximately 33% of clusters may be correlated by DYRK1A and SMARCA4. (D) Venn diagram highlighting shared peaks gained by DYRK1A and SMARCA4 complementation. (E) Correlation heatmap comparing changes in RNA abundance in DYRK1A or SMARCA4 complemented cells, identifying a correlation coefficient of 0.08 supporting (F) Gene set enrichment analysis from RNA-Seq experiments showing shared pathway regulation by DYRK1A and SMARCA4. Data underlying this figure can be found under GEO Accessions GSE213999 and GSE186201. DYRK1A, Dual Specificity Tyrosine Phosphorylation Regulated Kinase 1A; KO, knockout; WT, wild-type. (PDF)</p

DYRK1A drives ACE2 and DPP4 expression by altering chromatin accessibility.

(A) Principal component analysis of RNA-Seq experiments performed in WT Vero-E6, KO+vec, KO+WT, and KO+Y321F cells. Rep refers to independent biological replicates. (B) Heatmap depicting DEGs by RNA-Seq in WT Vero-E6, KO+vec, KO+WT, and KO+Y321F cells. (C) XY plot of RNA-Seq L2FC versus CRISPR z-scores in Vero-E6 cells [23] for SARS-CoV-2 (left), MERS-CoV (middle), or VSV-SARS-CoV-2-S (right). Denoted are receptor (ACE2, DPP4) and protease (CTSL) genes as significantly up-regulated proviral genes of interest. (D) RT-qPCR for ACE2 validates RNA-Seq results and supports partial rescue of ACE2 mRNA transcripts in cells where DYRK1A-WT or DYRK1A-Y321F are reintroduced. (E) Principal component analysis of ATAC-Seq experiments performed in WT Vero-E6, KO+vec, KO+WT, and KO+Y321F cells. Rep refers to independent biological replicates. (F) ATAC-Seq gene tracks for ACE2, highlighting increased accessibility at putative enhancers and near the TSS in the presence of DYRK1A. (G) ATAC-Seq gene tracks for DPP4, showing increased chromatin accessibility in the presence of DYRK1A. (H) ATAC-Seq genome tracks for CTSL, showing increased chromatin accessibility in the presence of DYRK1A. All experiments were performed in biological duplicate (RNA-Seq/ATAC-Seq) or triplicate (RT-qPCR). Data underlying this figure can be found in S1 Data and under GEO Accession GSE213999 (https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE213999). ACE2, angiotensin-converting enzyme 2; CTSL, Cathepsin L; DEG, differentially expressed gene; DPP4, dipeptidyl peptidase-4; DYRK1A, Dual Specificity Tyrosine Phosphorylation Regulated Kinase 1A; KO, knockout; L2FC, log2 fold-change; MERS-CoV, Middle East Respiratory Syndrome Coronavirus; RT-qPCR, quantitative reverse transcription PCR; SARS-CoV-2, Severe Acute Respiratory Syndrome Coronavirus 2; TSS, transcriptional start site; WT, wild-type.</p