Inhibition of interferon response by cystatin B: implication in HIV replication of macrophage reservoirs

Cystatin B and signal transducer and activator of transcription-1 (STAT-1) phosphorylation have recently been shown to increase human immunodeficiency virus-1 (HIV-1) replication in monocyte-derived macrophages (MDM), but the molecular pathways by which they do are unknown. We hypothesized that cystatin B inhibits the interferon (IFN) response and regulates STAT-1 phosphorylation by interacting with additional proteins. To test if cystatin B inhibits the IFN-β response, we performed luciferase reporter gene assays in Vero cells, which are IFN deficient. Interferon-stimulated response element (ISRE)-driven expression of firefly luciferase was significantly inhibited in Vero cells transfected with a cystatin B expression vector compared to cells transfected with an empty vector. To determine whether cystatin B interacts with other key players regulating STAT-1 phosphorylation and HIV-1 replication, cystatin B was immunoprecipitated from HIV-1-infected MDM. The protein complex was analyzed by liquid chromatography tandem mass spectrometry. Protein interactions with cystatin B were verified by Western blots and immunofluorescence with confocal imaging. Our findings confirmed that cystatin B interacts with pyruvate kinase M2 isoform, a protein previously associated cocaine enhancement of HIV-1 replication, and major vault protein (MVP), an IFN-responsive protein that interferes with JAK/STAT signals. Western blot studies confirmed the interaction with pyruvate kinase M2 isoform and MVP. Immunofluorescence studies of HIV-1-infected MDM showed that upregulated MVP colocalized with STAT-1. To our knowledge, the current study is the first to demonstrate the coexpression of cystatin B, STAT-1, MVP, and pyruvate kinase M2 isoform with HIV-1 replication in MDM and thus suggests novel targets for HIV-1 restriction in macrophages, the principal reservoirs for HIV-1 in the central nervous system

Practical "1-2-3-4-Day" Rule for Starting Direct Oral Anticoagulants After Ischemic Stroke With Atrial Fibrillation: Combined Hospital-Based Cohort Study

BACKGROUND: The "1-3-6-12-day rule" for starting direct oral anticoagulants (DOACs) in patients with nonvalvular atrial fibrillation after acute ischemic stroke or transient ischemic attack recommends timings that may be later than used in clinical practice. We investigated more practical optimal timing of DOAC initiation according to stroke severity. METHODS: The combined data of prospective registries in Japan, Stroke Acute Management with Urgent Risk-factor Assessment and Improvement-nonvalvular atrial fibrillation (September 2011 to March 2014) and RELAXED (February 2014 to April 2016) were used. Patients were divided into transient ischemic attack and 3 stroke subgroups by the National Institutes of Health Stroke Scale score: mild (0-7), moderate (8-15), and severe (≥16). The early treatment group was defined as patients starting DOACs earlier than the median initiation day in each subgroup. Outcomes included a composite of recurrent stroke or systemic embolism, ischemic stroke, and severe bleeding within 90 days. Six European prospective registries were used for validation. RESULTS: In the 1797 derivation cohort patients, DOACs were started at median 2 days after transient ischemic attack and 3, 4, and 5 days after mild, moderate, and severe strokes, respectively. Stroke or systemic embolism was less common in Early Group (n=785)-initiating DOACS within 1, 2, 3, and 4 days, respectively-than Late Group (n=1012) (1.9% versus 3.9%; adjusted hazard ratio, 0.50 [95% CI, 0.27-0.89]), as was ischemic stroke (1.7% versus 3.2%, 0.54 [0.27-0.999]). Major bleeding was similarly common in the 2 groups (0.8% versus 1.0%). On validation, both ischemic stroke (2.4% versus 2.2%) and intracranial hemorrhage (0.2% versus 0.6%) were similarly common in Early (n=547) and Late (n=1483) Groups defined using derivation data. CONCLUSIONS: In Japanese and European populations, early DOAC initiation within 1, 2, 3, or 4 days according to stroke severity seemed to be feasible to decrease the risk of recurrent stroke or systemic embolism and no increase in major bleeding. These findings support ongoing randomized trials to better establish the optimal timing of DOAC initiation

BMJ Open

INTRODUCTION: Worldwide, 2 million patients aged 18-50 years suffer a stroke each year, and this number is increasing. Knowledge about global distribution of risk factors and aetiologies, and information about prognosis and optimal secondary prevention in young stroke patients are limited. This limits evidence-based treatment and hampers the provision of appropriate information regarding the causes of stroke, risk factors and prognosis of young stroke patients. METHODS AND ANALYSIS: The Global Outcome Assessment Life-long after stroke in young adults (GOAL) initiative aims to perform a global individual patient data meta-analysis with existing data from young stroke cohorts worldwide. All patients aged 18-50 years with ischaemic stroke or intracerebral haemorrhage will be included. Outcomes will be the distribution of stroke aetiology and (vascular) risk factors, functional outcome after stroke, risk of recurrent vascular events and death and finally the use of secondary prevention. Subgroup analyses will be made based on age, gender, aetiology, ethnicity and climate of residence. ETHICS AND DISSEMINATION: Ethical approval for the GOAL study has already been obtained from the Medical Review Ethics Committee region Arnhem-Nijmegen. Additionally and when necessary, approval will also be obtained from national or local institutional review boards in the participating centres. When needed, a standardised data transfer agreement will be provided for participating centres. We plan dissemination of our results in peer-reviewed international scientific journals and through conference presentations. We expect that the results of this unique study will lead to better understanding of worldwide differences in risk factors, causes and outcome of young stroke patients

The HDAC Inhibitor FK228 Enhances Adenoviral Transgene Expression by a Transduction-Independent Mechanism but Does Not Increase Adenovirus Replication

The histone deacetylase inhibitor FK228 has previously been shown to enhance adenoviral transgene expression when cells are pre-incubated with the drug. Upregulation of the coxsackie adenovirus receptor (CAR), leading to increased viral transduction, has been proposed as the main mechanism. In the present study, we found that the highest increase in transgene expression was achieved when non-toxic concentrations of FK228 were added immediately after transduction, demonstrating that the main effect by which FK228 enhances transgene expression is transduction-independent. FK228 had positive effects both on Ad5 and Ad5/f35 vectors with a variety of transgenes and promoters, indicating that FK228 works mainly by increasing transgene expression at the transcriptional level. In some cases, the effects were dramatic, as demonstrated by an increase in CD40L expression by FK228 from 0.3% to 62% when the murine prostate cancer cell line TRAMP-C2 was transduced with Ad[CD40L]. One unexpected finding was that FK228 decreased the transgene expression of an adenoviral vector with the prostate cell-specific PPT promoter in the human prostate adenocarcinoma cell lines LNCaP and PC-346C. This is probably a consequence of alteration of the adenocarcinoma cell lines towards a neuroendocrine differentiation after FK228 treatment. The observations in this study indicate that FK228 enhances adenoviral therapy by a transduction-independent mechanism. Furthermore, since histone deacetylase inhibitors may affect the differentiation of cells, it is important to keep in mind that the activity and specificity of tissue- and tumor-specific promoters may also be affected

Induction of Sodium/Iodide Symporter (NIS) Expression and Radioiodine Uptake in Non-Thyroid Cancer Cells

Background: This study was designed to explore the therapeutic potential of suppressing MAP kinase and PI3K/Akt pathways and histone deacetylase (HDAC) to induce the expression of sodium/iodide symporter (NIS) and radioiodine uptake in non-thyroid cancer cells. Methods: We tested the effects of the MEK inhibitor RDEA119, the Akt inhibitor perifosine, and the HDAC inhibitor SAHA on NIS expression in thirteen human cancer cell lines derived from melanoma, hepatic carcinoma, gastric carcinoma, colon carcinoma, breast carcinoma, and brain cancers. We also examined radioiodine uptake and histone acetylation at the NIS promoter in selected cells. Results: Overall, the three inhibitors could induce NIS expression, to various extents, in melanoma and all the epithelial carcinoma-derived cells but not in brain cancer-derived cells. SAHA was most effective and its effect could be significantly enhanced by RDEA119 and perifosine. The expression of NIS, at both mRNA and protein levels, was most robust in the melanoma cell M14, hepatic carcinoma cell HepG2, and the gastric carcinoma cell MKN-7 cell. Radioiodine uptake was correspondingly induced, accompanied by robust increase in histone acetylation at the NIS promoter, in these cells when treated with the three inhibitors. Conclusions: This is the first demonstration that simultaneously suppressing the MAP kinase and PI3K/Akt pathways and HDAC could induce robust NIS expression and radioiodine uptake in certain non-thyroid human cancer cells, providing novel therapeutic implications for adjunct radioiodine treatment of these cancers

Bub1 Is a Fission Yeast Kinetochore Scaffold Protein, and Is Sufficient to Recruit other Spindle Checkpoint Proteins to Ectopic Sites on Chromosomes

The spindle checkpoint delays anaphase onset until all chromosomes have attached in a bi-polar manner to the mitotic spindle. Mad and Bub proteins are recruited to unattached kinetochores, and generate diffusible anaphase inhibitors. Checkpoint models propose that Mad1 and Bub1 act as stable kinetochore-bound scaffolds, to enhance recruitment of Mad2 and Mad3/BubR1, but this remains untested for Bub1. Here, fission yeast FRAP experiments confirm that Bub1 stably binds kinetochores, and by tethering Bub1 to telomeres we demonstrate that it is sufficient to recruit anaphase inhibitors in a kinase-independent manner. We propose that the major checkpoint role for Bub1 is as a signalling scaffold

First-in-Human Phase I Study of an Oral HSP90 Inhibitor, TAS-116, in Patients with Advanced Solid Tumors.

HSP90 is involved in stability and function of cancer-related proteins. This study was conducted to define the MTD, safety, pharmacokinetics, pharmacodynamics, and preliminary antitumor efficacy of TAS-116, a novel class, orally available, highly selective inhibitor of HSP90. Patients with advanced solid tumors received TAS-116 orally once daily (QD, step 1) or every other day (QOD, step 2) in 21-day cycles. Each step comprised a dose escalation phase to determine MTD and an expansion phase at the MTD. In the dose escalation phase, an accelerated dose-titration design and a "3+3" design were used. Sixty-one patients were enrolled in Japan and the United Kingdom. MTD was determined to be 107.5 mg/m2/day for QD, and 210.7 mg/m2/day for QOD. In the expansion phase of step 1, TAS-116 was administered 5 days on/2 days off per week (QD × 5). The most common treatment-related adverse events included gastrointestinal disorders, creatinine increases, AST increases, ALT increases, and eye disorders. Eye disorders have been reported with HSP90 inhibitors; however, those observed with TAS-116 in the expansion phases were limited to grade 1. The systemic exposure of TAS-116 increased dose-proportionally with QD and QOD regimens. Two patients with non-small cell lung cancer and one patient with gastrointestinal stromal tumor (GIST) achieved a confirmed partial response. TAS-116 had an acceptable safety profile with some antitumor activity, supporting further development of this HSP90 inhibitor.This is a result from a first-in-human study, in which the HSP90 inhibitor TAS-116 demonstrated preliminary antitumor efficacy in patients with advanced solid tumors, including those with heavily pretreated GIST