The Nuclear Chaperone Nucleophosmin Escorts an Epstein-Barr Virus Nuclear Antigen to Establish Transcriptional Cascades for Latent Infection in Human B Cells

Epstein-Barr Virus (EBV) is an oncogenic γ-herpesvirus that capably establishes both latent and lytic modes of infection in host cells and causes malignant diseases in humans. Nuclear antigen 2 (EBNA2)-mediated transcription of both cellular and viral genes is essential for the establishment and maintenance of the EBV latency program in B lymphocytes. Here, we employed a protein affinity pull-down and LC-MS/MS analysis to identify nucleophosmin (NPM1) as one of the cellular proteins bound to EBNA2. Additionally, the specific domains that are responsible for protein-protein interactions were characterized as EBNA2 residues 300 to 360 and the oligomerization domain (OD) of NPM1. As in c-MYC, dramatic NPM1 expression was induced in EBV positively infected B cells after three days of viral infection, and both EBNA2 and EBNALP were implicated in the transactivation of the NPM1 promoter. Depletion of NPM1 with the lentivirus-expressed short-hairpin RNAs (shRNAs) effectively abrogated EBNA2-dependent transcription and transformation outgrowth of lymphoblastoid cells. Notably, the ATP-bound state of NPM1 was required to induce assembly of a protein complex containing EBNA2, RBP-Jκ, and NPM1 by stabilizing the interaction of EBNA2 with RBP-Jκ. In a NPM1-knockdown cell line, we demonstrated that an EBNA2-mediated transcription defect was fully restored by the ectopic expression of NPM1. Our findings highlight the essential role of NPM1 in chaperoning EBNA2 onto the latency-associated membrane protein 1 (LMP1) promoters, which is coordinated with the subsequent activation of transcriptional cascades through RBP-Jκ during EBV infection. These data advance our understanding of EBV pathology and further imply that NPM1 can be exploited as a therapeutic target for EBV-associated diseases

Apamin-Sensitive Calcium-Activated Potassium Currents in Rabbit Ventricles with Chronic Myocardial Infarction

Introduction Apamin-sensitive small-conductance calcium-activated potassium current (IKAS) is increased in heart failure. It is unknown if myocardial infarction (MI) is also associated with an increase of IKAS. Methods and Results We performed Langendorff perfusion and optical mapping in 6 normal hearts and 10 hearts with chronic (5 weeks) MI. An additional 6 normal and 10 MI hearts were used for patch clamp studies. The infarct size was 25% [95% confidence interval, 20 to 31] and the left ventricular ejection fraction was 0.5 [0.46 to 0.54]. The rabbits did not have symptoms of heart failure. The action potential duration measured to 80% repolarization (APD80) in the peri-infarct zone (PZ) was150 [142 to 159] ms, significantly (p=0.01) shorter than in the normal ventricles (158 to 177] ms). The intracellular Ca transient duration was also shorter in the PZ (148 [139 to 157] ms) than in normal ventricles (168 [157 to 180] ms; P=0.017). Apamin prolonged the APD80 in PZ by 9.8 [5.5 to 14.1] %, which is greater than in normal ventricles (2.8 [1.3 to 4.3] %, p=0.006). Significant shortening of APD80 was observed at the cessation of rapid pacing in MI but not in normal ventricles. Apamin prevented postpacing APD80 shortening. Patch clamp studies showed that IKAS was significantly higher in the PZ cells (2.51 [1.55 to 3.47] pA/pF, N=17) than in the normal cells (1.08 [0.36 to 1.80] pA/pF, N=15, p=0.019). Conclusion We conclude that IKAS is increased in MI ventricles and contributes significantly to ventricular repolarization especially during tachycardia

Hypokalemia Promotes Late Phase 3 Early Afterdepolarization and Recurrent Ventricular Fibrillation During Isoproterenol Infusion in Langendorff Perfused Rabbit Ventricles

BACKGROUND Hypokalemia and sympathetic activation are commonly associated with electrical storm (ES) in normal and diseased hearts. The mechanisms remain unclear. OBJECTIVE To test the hypothesis that late phase 3 early afterdepolarization (EAD) induced by IKATP activation underlies the mechanisms of ES during isoproterenol infusion and hypokalemia. METHODS Intracellular calcium (Cai) and membrane voltage were optically mapped in 32 Langendorff-perfused normal rabbit hearts. RESULTS Repeated episodes of electrically-induced VF at baseline did not result in spontaneous VF (SVF). During isoproterenol infusion, SVF occurred in 1 of 15 hearts (7%) studied in normal extracellular potassium ([K+]o) (4.5 mmol/L), 3 of 8 hearts (38%) in 2.0 mmol/L [K+]o, 9 of 10 hearts (90%) in 1.5 mmol/L [K+]o, and 7 of 7 hearts (100%) in 1.0 mmol/L [K+]o (P<0.001). Optical mapping showed isoproterenol and hypokalemia enhanced Cai transient duration (CaiTD) and heterogeneously shortened action potential duration (APD) after defibrillation, leading to late phase 3 EAD and SVF. IKATP blocker (glibenclamide, 5 μmol/L) reversed the post-defibrillation APD shortening and suppressed recurrent SVF in all hearts studied despite no evidence of ischemia. Nifedipine reliably prevented recurrent VF when given before, but not after, the development of VF. IKr blocker (E-4031) and small conductance calcium activated potassium channel blocker (apamin) failed to prevent recurrent SVF. CONCLUSION Beta-adrenergic stimulation and concomitant hypokalemia could cause non-ischemic activation of IKATP, heterogeneous APD shortening and prolongation of CaiTD to provoke late phase 3 EAD, triggered activity and recurrent SVF. IKATP inhibition may be useful in managing ES during resistant hypokalemia

A Novel Role of Matrix Metalloproteinase-8 in Macrophage Differentiation and Polarization

This work forms part of the research themes contributing to the translational research portfolio of Barts and the London Cardiovascular Biomedical Research Unit, which is supported and funded by the National Institute of Health Research

Assessment of Near-Bottom Water Quality of Southwestern Coast of Sarawak, Borneo, Malaysia: A Multivariate Statistical Approach

The study on Sarawak coastal water quality is scarce, not to mention the application of the multivariate statistical approach to investigate the spatial variation of water quality and to identify the pollution source in Sarawak coastal water. Hence, the present study aimed to evaluate the spatial variation of water quality along the coastline of the southwestern region of Sarawak using multivariate statistical techniques. Seventeen physicochemical parameters were measured at 11 stations along the coastline with approximately 225 km length. The coastal water quality showed spatial heterogeneity where the cluster analysis grouped the 11 stations into four different clusters. Deterioration in coastal water quality has been observed in different regions of Sarawak corresponding to land use patterns in the region.Nevertheless, nitrate-nitrogen exceeded the guideline value at all sampling stations along the coastline. The principal component analysis (PCA) has determined a reduced number of five principal components that explained 89.0% of the data set variance. The first PC indicated that the nutrients were the dominant polluting factors, which is attributed to the domestic, agricultural, and aquaculture activities, followed by the suspended solids in the second PC which are related to the logging activities

Erratum: Sequence data and association statistics from 12,940 type 2 diabetes cases and controls.

This corrects the article DOI: 10.1038/sdata.2017.179

Identifying co-targets to fight drug resistance based on a random walk model

Abstract- Drug resistance has now posed more severe and emergent threats to human health and infectious disease treatment. However, the wet-lab approaches alone to counter drug resistance have so far achieved limited success in understanding the underlying mechanisms and pathways of drug resistance. Our approach applied A * heuristic search algorithm in order to extract drug response pathways from protein-protein interaction networks and to identify the co-target for effective antibacterial drugs. In this paper, we chose one of the killer infectious diseases, Mycobacterium Tuberculosis as our test bed. The results showed that the acetyl-CoA carboxylase is believed to be involved in fatty acid and mycolic acid biosynthesis and is strongly associated with the drug resistance mechanisms. Our analysis are consistent with the recent experimental results and also found alanine and glycine rich membrane and cell wall-associated lipoproteins to be potential co-targets for countering drug resistance. keywords: Drug resistance, Co-target, Random walk, Mycobacterium Tuberculosi

Characteristics and Source-specific Health Risks of Ambient PM2.5-bound PAHs in an Urban City of Northern Taiwan

Polycyclic aromatic hydrocarbons (PAHs) with highly toxic compounds mainly exist in small-sized particles and can induce considerable human health risks. Studies on PM2.5-bound PAHs and their source-specific human health risks still remain scarce. Daily PM2.5 samples (n = 119) were collected every three days from 2016 to 2017 in Taipei city, Taiwan. Fifteen PAHs in PM2.5 were analyzed via gas chromatography tandem mass spectrometry (GC/MS-MS). We utilized a positive matrix factorization (PMF) model, diagnostic ratios, and potential source contribution function (PSCF) to identify the origins of PM2.5-bound PAHs. The annual concentration of total PAHs (TPAH) was 0.79 ± 0.67 ng m–3 (range = 0.11–3.27 ng m–3). The highest and lowest values of TPAH appeared in winter and autumn with a mean of 1.36 ng m–3 and 0.43 ng m–3, respectively. The contributions of high-molecular-weight PAHs (HMW PAHs) to TPAH were notably higher than those of low-molecularweight PAHs (LMW PAHs) during the sampling period. Benzo[ghi]perylene (BghiP) accounted for the highest percentage (23.9%) of TPAH among selected congeners. Traffic emissions (31.3%) were identified as the predominant contributor to ambient PM2.5-bound PAHs, followed by industrial emissions (29.2%), evaporated/unburned oil (22.3%), and biomass/coal combustion (17.1%). Apart from the local sources, PSCF-derived results showed that emissions from industrial activities in northeast China and shipping around the Yellow Sea and East China Sea could affect the PAHs in the study area. Traffic emissions were the strongest contributor to human health risk, thus pointing to the significance of control over vehicle exhaust. This study suggests that it is necessary to distinguish the sources of the PM2.5-bound PAHs in order to underpin preventive and mitigative strategies for protecting environmental and public health