KCNQ1 and KCNE1 in the IKs Channel Complex Make State-dependent Contacts in their Extracellular Domains

KCNQ1 and KCNE1 (Q1 and E1) associate to form the slow delayed rectifier IKs channels in the heart. A short stretch of eight amino acids at the extracellular end of S1 in Q1 (positions 140–147) harbors six arrhythmia-associated mutations. Some of these mutations affect the Q1 channel function only when coexpressed with E1, suggesting that this Q1 region may engage in the interaction with E1 critical for the IKs channel function. Identifying the Q1/E1 contact points here may provide new insights into how the IKs channel operates. We focus on Q1 position 145 and E1 positions 40–43. Replacing all native cysteine (Cys) in Q1 and introducing Cys into the above Q1 and E1 positions do not significantly perturb the Q1 channel function or Q1/E1 interactions. Immunoblot experiments on COS-7 cells reveal that Q1 145C can form disulfide bonds with E1 40C and 41C, but not E1 42C or 43C. Correspondingly, voltage clamp experiments in oocytes reveal that Q1 145C coexpressed with E1 40C or E1 41C manifests unique gating behavior and DTT sensitivity. Our data suggest that E1 40C and 41C come close to Q1 145C in the activated and resting states, respectively, to allow disulfide bond formation. These data and those in the literature lead us to propose a structural model for the Q1/E1 channel complex, in which E1 is located between S1, S4, and S6 of three separate Q1 subunits. We propose that E1 is not a passive partner of the Q1 channel, but instead can engage in molecular motions during IKs gating

Community-acquired Methicillin-resistant Staphylococcus aureus in Children, Taiwan

Highly virulent community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) with Panton-Valentine leukocidin (PVL) is common worldwide. Using antimicrobial drug susceptibility testing, staphylococcal cassette chromosome mec typing, exotoxin profiling, and pulsed-field gel electrophoresis typing, we provide evidence that supports the relationship between nasal strains of PVL-positive MRSA and community-acquired disease

Frequency Dependent Alterations in Regional Homogeneity of Baseline Brain Activity in Schizophrenia

Low frequency oscillations are essential in cognitive function impairment in schizophrenia. While functional connectivity can reveal the synchronization between distant brain regions, the regional abnormalities in task-independent baseline brain activity are less clear, especially in specific frequency bands. Here, we used a regional homogeneity (ReHo) method combined with resting-state functional magnetic resonance imaging to investigate low frequency spontaneous neural activity in the three different frequency bands (slow-5:0.01–0.027 Hz; slow-4:0.027–0.08 Hz; and typical band: 0.01–0.08 Hz) in 69 patients with schizophrenia and 62 healthy controls. Compared with controls, schizophrenia patients exhibited decreased ReHo in the precentral gyrus, middle occipital gyrus, and posterior insula, whereas increased ReHo in the medial prefrontal cortex and anterior insula. Significant differences in ReHo between the two bands were found in fusiform gyrus and superior frontal gyrus (slow-4> slow-5), and in basal ganglia, parahippocampus, and dorsal middle prefrontal gyrus (slow-5> slow-4). Importantly, we identified significant interaction between frequency bands and groups in the inferior occipital gyrus and caudate body. This study demonstrates that ReHo changes in schizophrenia are widespread and frequency dependent

Predicting customer lifetime value for hypermarket private label products

This study develops a model to predict customer lifetime value for hypermarket private label products. It examines the relationships among store awareness, store image variables (i.e., service quality, price/value, convenience, and product quality), private label image, repurchase intention, and customer lifetime value and investigates the moderating role of image fit. The originality of this study lies in filling the gap of previous research on antecedents of private label customers’ behavior by considering store awareness, image fit, and customer lifetime value. Partial least squares structural equation modeling was used to analyze data. The results indicate the following. Store image variables (except product quality) and store awareness affect repurchase intention directly or indirectly through private label image. Image fit moderates the relationships between store image variables (except product quality) and private label image. Private label image facilitates customer lifetime value. This study provides several theoretical and practical implications for hypermarket private label product developments

Exponential ATP amplification through simultaneous regeneration from AMP and pyrophosphate for luminescence detection of bacteria

a b s t r a c t Bacteria monitoring is essential for many industrial manufacturing processes, particularly those involving in food, biopharmaceuticals, and semiconductor production. Firefly luciferase ATP luminescence assay is a rapid and simple bacteria detection method. However, the detection limit of this assay for Escherichia coli is approximately 10 4 colony-forming units (CFU), which is insufficient for many applications. This study aims to improve the assay sensitivity by simultaneous conversion of PP i and AMP, two products of the luciferase reaction, back to ATP to form two chain-reaction loops. Because each consumed ATP continuously produces two new ATP molecules, this approach can achieve exponential amplification of ATP. Two consecutive enzyme reactions were employed to regenerate AMP into ATP: adenylate kinase converting AMP into ADP using UTP as the energy source, and acetate kinase catalyzing acetyl phosphate and ADP into ATP. The PP i -recycling loop was completed using ATP sulfurylase and adenosine 5 0 phosphosulfate. The modification maintains good quantification linearity in the ATP luminescence assay and greatly increases its bacteria detection sensitivity. This improved method can detect bacteria concentrations of fewer than 10 CFU. This exponential ATP amplification assay will benefit bacteria monitoring in public health and manufacturing processes that require high-quality water. Ó 2011 Elsevier Inc. All rights reserved. Bacteria monitoring is essential for many industrial manufacturing processes, and particularly those involving food, semiconductors, and biopharmaceuticals. The presence of bacteria reduces production yield and may cause serious health problems in humans. Researchers have developed several rapid assays for detecting bacteria in water. These methods include polymerase chain reactions, fluorescence in situ hybridization [1], b-D-glucuronidase activity measurement The ATP luminescence assay is a rapid, sensitive, and easy-toperform method based on the detection of ATP, a molecule ubiquitously present in all living cells. The enzyme luciferase catalyzes the oxidation of the substrate luciferin while transforming the energy derived from ATP into light, which can be quantified by a luminometer. This assay has been widely used in bacteria monitoring for food hygiene [4] and surface cleanliness The current detection limit of the ATP luminescence method for Escherichia coli is approximately 10 4 colony-forming units (CFU) 1 [12,13], which is not sensitive enough for many industrial and medical applications. Several approaches have been adopted to improve the assay sensitivity. The first strategy involves the identification of chemical extractants that can effectively disrupt bacterial cells while not interfering with the luminescence assay. Both dimethyl sulfoxide (DMSO) 0003-2697/$ -see front matter

miRTarBase update 2014: an information resource for experimentally validated miRNA-target interactions

MicroRNAs (miRNAs) are small non-coding RNA molecules capable of negatively regulating gene expression to control many cellular mechanisms. The miRTarBase database (http://mirtarbase.mbc.nctu.edu.tw/) provides the most current and comprehensive information of experimentally validated miRNA-target interactions. The database was launched in 2010 with data sources for >100 published studies in the identification of miRNA targets, molecular networks of miRNA targets and systems biology, and the current release (2013, version 4) includes significant expansions and enhancements over the initial release (2010, version 1). This article reports the current status of and recent improvements to the database, including (i) a 14-fold increase to miRNA-target interaction entries, (ii) a miRNA-target network, (iii) expression profile of miRNA and its target gene, (iv) miRNA target-associated diseases and (v) additional utilities including an upgrade reminder and an error reporting/user feedback system

SirT1—A Sensor for Monitoring Self-Renewal and Aging Process in Retinal Stem Cells

Retinal stem cells bear potency of proliferation, self-renewal, and differentiation into many retinal cells. Utilizing appropriate sensors one can effectively detect the self-renewal and aging process abilities. Silencing information regulator (SirT1), a member of the sirtuin family, is a NAD-dependent histone deacetylase and an essential mediator for longevity in normal cells by calorie restriction. We firstly investigate the SirT1 mRNA expression in retinal stem cells from rats and 19 human eyes of different ages. Results revealed that SirT1 expression was significantly decreased in in vivo aged eyes, associated with poor self-renewal abilities. Additionally, SirT1 mRNA levels were dose-dependently increased in resveratrol- treated retinal stem cells. The expression of SirT1 on oxidative stress-induced damage was significantly decreased, negatively correlated with the level of intracellular reactive oxygen species production. Treatment with resveratrol could effectively further reduce oxidative stress induced by H2O2 treatment in retinal stem cells. Importantly, the anti-oxidant effects of resveratrol in H2O2-treated retinal stem cells were significantly abolished by knockdown of SirT1 expression (sh-SirT1). SirT1 expression provides a feasible sensor in assessing self-renewal and aging process in retinal stem cells. Resveratrol can prevent reactive oxygen species-induced damages via increased retinal SirT1 expression

Combination of everolimus with trastuzumab plus paclitaxel as first-line treatment for patients with HER2-positive advanced breast cancer (BOLERO-1) : a phase 3, randomised, double-blind, multicentre trial

BACKGROUND : mTOR inhibition has been shown to reverse trastuzumab resistance from hyperactivated the PIK/AKT/mTOR pathway due to PTEN loss, by sensitizing PTEN-deficient tumors towards trastuzumab. The BOLERO-1 study evaluated the efficacy and safety of adding everolimus to trastuzumab and paclitaxel as first-line therapy for HER2+ advanced breast cancer (ABC). METHODS : In this phase III, randomized, double-blind trial, patients were enrolled across 141 sites in 28 countries. Eligible patients were ≥18 years of age, with locally assessed HER2+ advanced breast cancer (ABC), with Eastern Cooperative Oncology Group performance status of 0-1, who had not received prior trastuzumab or chemotherapy for ABC, had measurable disease as per Response Evaluation Criteria in Solid Tumors or bone lesions in the absence of measurable disease, without prior systemic therapy for advanced disease except endocrine therapy. The patients were randomized 2:1 (with an interactive voice and web response system) to receive either daily everolimus (10 mg/day) orally or placebo plus weekly trastuzumab intravenously at 4 mg/kg loading dose on Day-1 with subsequent weekly doses of 2 mg/kg of each 4-week cycle plus paclitaxel intravenously at a dose of 80 mg/m2 on days 1, 8, and 15 of each 4- week cycle. Randomization was stratified according to prior use of trastuzumab and visceral metastasis. Patients and investigators were blinded to the assigned treatments. Identity of experimental treatments was concealed by use of everolimus and placebo that were identical in packaging, labelling, appearance, and administration schedule. The two primary objectives were investigator-assessed progression-free survival (PFS) in the full study population and in the subset of patients with hormone receptor-negative (HR) breast cancer at baseline; the latter was added during the course of the study, prior to unblinding based on new clinical and biological findings from other studies. All efficacy analyses were based on the intention-to-treat population. Enrolment for this trial is closed and results of the final PFS analyses are presented here. Clinicaltrials.gov identifier: NCT00876395. FINDINGS : Between 10-Sep-2009 and 16-Dec-2012, 719 patients were randomized to receive everolimus (n=480) or placebo (n=239). Median follow-up was 41.3 months (IQR: 35.4 – 46.6 months). INTERPRETATION : The primary objective in the full population was not met; median PFS was 15.0 months with everolimus vs 14.5 months with placebo (hazard ratio, 0.89; 95% CI, 0.73-1.08; p=0.1166). In the HR subpopulation (n=311), median PFS with everolimus was 20.3 months vs 13.1 months with placebo (hazard ratio, 0.66; 95% CI, 0.48-0.91; p=0.0049), however, the protocol-specified statistical significance threshold (p=0.0044) was not crossed. The most common adverse events (AEs) with everolimus vs placebo were stomatitis (314 [66.5%] vs 77 [32.4%] patients), diarrhea (267 [56.6%] vs 111 [46.6%] patients), and alopecia (221 [46.8%] vs 125 [52.5%]). The most frequently reported grade 3/4 AEs in the EVE arm vs PBO arm were neutropenia (117 [24.8%] of 472 patients vs 35 [14.7%] of 238 patients), stomatitis (59 [12.5%] of 472 patients vs 3 [1.3%] of 238 patients), anemia (46 [9.7%] of 472 patients vs 6 [2.5%] of 238 patients) and diarrhea (43 [9.1%] of 472 patients vs 10 [4.2%] of 238 patients) On-treatment AE-related deaths were reported in 17 [3.6%] vs 0% of patients respectively.Interpretation: The primary objective of PFS was not met. However, consistent with the preliminary observations from BOLERO-3, everolimus prolonged median PFS by 7.2 months in patients with HR, HER2+ ABC, which warrants further investigation. The safety profile was generally consistent with what was previously reported in BOLERO-3. Proactive monitoring and early management of AEs in patients treated with everolimus and chemotherapy is critical..Novartis Pharmaceuticals Corporation.http://www.journals.elsevier.com/the-lancet-oncology2016-07-31hb201

RANKL Is a Downstream Mediator for Insulin-Induced Osteoblastic Differentiation of Vascular Smooth Muscle Cells

Several reports have shown that circulating insulin level is positively correlated with arterial calcification; however, the relationship between insulin and arterial calcification remains controversial and the mechanism involved is still unclear. We used calcifying vascular smooth muscle cells (CVSMCs), a specific subpopulation of vascular smooth muscle cells that could spontaneously express osteoblastic phenotype genes and form calcification nodules, to investigate the effect of insulin on osteoblastic differentiation of CVSMCs and the cell signals involved. Our experiments demonstrated that insulin could promote alkaline phosphatase (ALP) activity, osteocalcin expression and the formation of mineralized nodules in CVSMCs. Suppression of receptor activator of nuclear factor κB ligand (RANKL) with small interfering RNA (siRNA) abolished the insulin-induced ALP activity. Insulin induced the activation of extracellular signal-regulated kinase (ERK)1/2, mitogen-activated protein kinase (MAPK) and RAC-alpha serine/threonine-protein kinase (Akt). Furthermore, pretreatment of human osteoblasts with the ERK1/2 inhibitor PD98059, but not the phosphoinositide 3-kinase (PI3K) inhibitor, LY294002, or the Akt inhibitor, 1L-6-hydroxymethyl-chiro-inositol 2-(R)-2-O-methyl-3-O-octadecylcarbonate (HIMO), abolished the insulin-induced RANKL secretion and blocked the promoting effect of insulin on ALP activities of CVSMCs. Recombinant RANKL protein recovered the ALP activities decreased by RANKL siRNA in insulin-stimulated CVSMCs. These data demonstrated that insulin could promote osteoblastic differentiation of CVSMCs by increased RANKL expression through ERK1/2 activation, but not PI3K/Akt activation

The C-Terminus of Histone H2B Is Involved in Chromatin Compaction Specifically at Telomeres, Independently of Its Monoubiquitylation at Lysine 123

Telomeric heterochromatin assembly in budding yeast propagates through the association of Silent Information Regulator (SIR) proteins with nucleosomes, and the nucleosome array has been assumed to fold into a compacted structure. It is believed that the level of compaction and gene repression within heterochromatic regions can be modulated by histone modifications, such as acetylation of H3 lysine 56 and H4 lysine 16, and monoubiquitylation of H2B lysine 123. However, it remains unclear as to whether or not gene silencing is a direct consequence of the compaction of chromatin. Here, by investigating the role of the carboxy-terminus of histone H2B in heterochromatin formation, we identify that the disorderly compaction of chromatin induced by a mutation at H2B T122 specifically hinders telomeric heterochromatin formation. H2B T122 is positioned within the highly conserved AVTKY motif of the αC helix of H2B. Heterochromatin containing the T122E substitution in H2B remains inaccessible to ectopic dam methylase with dramatically increased mobility in sucrose gradients, indicating a compacted chromatin structure. Genetic studies indicate that this unique phenotype is independent of H2B K123 ubiquitylation and Sir4. In addition, using ChIP analysis, we demonstrate that telomere structure in the mutant is further disrupted by a defect in Sir2/Sir3 binding and the resulting invasion of euchromatic histone marks. Thus, we have revealed that the compaction of chromatin per se is not sufficient for heterochromatin formation. Instead, these results suggest that an appropriately arrayed chromatin mediated by H2B C-terminus is required for SIR binding and the subsequent formation of telomeric chromatin in yeast, thereby identifying an intrinsic property of the nucleosome that is required for the establishment of telomeric heterochromatin. This requirement is also likely to exist in higher eukaryotes, as the AVTKY motif of H2B is evolutionarily conserved