Lutein Protects against Methotrexate-Induced and Reactive Oxygen Species-Mediated Apoptotic Cell Injury of IEC-6 Cells

Purpose High-dose chemotherapy using methotrexate (MTX) frequently induces side effects such as mucositis that leads to intestinal damage and diarrhea. Several natural compounds have been demonstrated of their effectiveness in protecting intestinal epithelial cells from these adverse effects. In this paper, we investigated the protection mechanism of lutein against MTX-induced damage in IEC-6 cells originating from the rat jejunum crypt. Methods: The cell viability, induced-apoptosis, reactive oxygen species (ROS) generation, and mitochondrial membrane potential in IEC-6 cells under MTX treatment were examined in the presence or absence of lutein. Expression level of Bcl2, Bad and ROS scavenging enzymes (including SOD, catalase and Prdx1) were detected by quantitative RT-PCR. Results: The cell viability of IEC-6 cells exposed to MTX was decreased in a dose- and time-dependent manner. MTX induces mitochondrial membrane potential loss, ROS generation and caspase 3 activation in IEC-6 cells. The cytotoxicity of MTX was reduced in IEC-6 cells by the 24 h pre-treatment of lutein. We found that pre-treatment of lutein significantly reduces MTX-induced ROS and apoptosis. The expression of SOD was up-regulated by the pre-treatment of lutein in the MTX-treated IEC-6 cells. These results indicated that lutein can protect IEC-6 cells from the chemo-drugs induced damage through increasing ROS scavenging ability. Conclusion: The MTX-induced apoptosis of IEC-6 cells was shown to be repressed by the pre-treatment of lutein, which may represent a promising adjunct to conventional chemotherapy for preventing intestinal damages

Genotoxic Klebsiella pneumoniae in Taiwan

Colibactin is a nonribosomal peptide-polyketide synthesized by multi-enzyme complexes encoded by the pks gene cluster. Colibactin-producing Escherichia coli have been demonstrated to induce host DNA damage and promote colorectal cancer (CRC) development. In Taiwan, the occurrence of pyogenic liver abscess (PLA) has been suggested to correlate with an increasing risk of CRC, and Klebsiella pneumoniae is the predominant PLA pathogen in Taiwan

Ventricular divergence correlates with epicardial wavebreaks and predicts ventricular arrhythmia in isolated rabbit hearts during therapeutic hypothermia

INTRODUCTION: High beat-to-beat morphological variation (divergence) on the ventricular electrogram during programmed ventricular stimulation (PVS) is associated with increased risk of ventricular fibrillation (VF), with unclear mechanisms. We hypothesized that ventricular divergence is associated with epicardial wavebreaks during PVS, and that it predicts VF occurrence. METHOD AND RESULTS: Langendorff-perfused rabbit hearts (n = 10) underwent 30-min therapeutic hypothermia (TH, 30°C), followed by a 20-min treatment with rotigaptide (300 nM), a gap junction modifier. VF inducibility was tested using burst ventricular pacing at the shortest pacing cycle length achieving 1:1 ventricular capture. Pseudo-ECG (p-ECG) and epicardial activation maps were simultaneously recorded for divergence and wavebreaks analysis, respectively. A total of 112 optical and p-ECG recordings (62 at TH, 50 at TH treated with rotigaptide) were analyzed. Adding rotigaptide reduced ventricular divergence, from 0.13±0.10 at TH to 0.09±0.07 (p = 0.018). Similarly, rotigaptide reduced the number of epicardial wavebreaks, from 0.59±0.73 at TH to 0.30±0.49 (p = 0.036). VF inducibility decreased, from 48±31% at TH to 22±32% after rotigaptide infusion (p = 0.032). Linear regression models showed that ventricular divergence correlated with epicardial wavebreaks during TH (p<0.001). CONCLUSION: Ventricular divergence correlated with, and might be predictive of epicardial wavebreaks during PVS at TH. Rotigaptide decreased both the ventricular divergence and epicardial wavebreaks, and reduced the probability of pacing-induced VF during TH

A Single-Cell Level and Connectome-Derived Computational Model of the Drosophila Brain

Computer simulations play an important role in testing hypotheses, integrating knowledge, and providing predictions of neural circuit functions. While considerable effort has been dedicated into simulating primate or rodent brains, the fruit fly (Drosophila melanogaster) is becoming a promising model animal in computational neuroscience for its small brain size, complex cognitive behavior, and abundancy of data available from genes to circuits. Moreover, several Drosophila connectome projects have generated a large number of neuronal images that account for a significant portion of the brain, making a systematic investigation of the whole brain circuit possible. Supported by FlyCircuit (http://www.flycircuit.tw), one of the largest Drosophila neuron image databases, we began a long-term project with the goal to construct a whole-brain spiking network model of the Drosophila brain. In this paper, we report the outcome of the first phase of the project. We developed the Flysim platform, which (1) identifies the polarity of each neuron arbor, (2) predicts connections between neurons, (3) translates morphology data from the database into physiology parameters for computational modeling, (4) reconstructs a brain-wide network model, which consists of 20,089 neurons and 1,044,020 synapses, and (5) performs computer simulations of the resting state. We compared the reconstructed brain network with a randomized brain network by shuffling the connections of each neuron. We found that the reconstructed brain can be easily stabilized by implementing synaptic short-term depression, while the randomized one exhibited seizure-like firing activity under the same treatment. Furthermore, the reconstructed Drosophila brain was structurally and dynamically more diverse than the randomized one and exhibited both Poisson-like and patterned firing activities. Despite being at its early stage of development, this single-cell level brain model allows us to study some of the fundamental properties of neural networks including network balance, critical behavior, long-term stability, and plasticity

Characterisation of protein-nanoparticleconjugates

Depending on the nature of the nanoparticles, reactive oxygen species may be generated, thus disturbing the oxidative balance in the lung environment. The toxicity of the particle may be mitigated by components of the epithelial lining fluid, such as antioxidants. The presence of protein in the lining fluid could also resolve the biological effects of particle exposure. However, the mechanisms of protein-particle interaction remain unclear. Hydrophobic carbon-based nanoparticles were used to investigate the interactions between bovine serum albumin (BSA) and particles, including carbon black, which has an average diameter of 23 nm (CB23) or 65 nm (CB65); single-walled nanotubes (SWNTs), which have an average diameter of 1−2 nm (500 nm in length); and double-walled nanotubes (DWNTs), which have an average diameter of 5 nm (5−15 μm in length). The zeta potentials of the particles alone and of the protein-particle conjugates were determined (Figure 1). The zeta potentials of CB23, CB65, SWNTs and DWNTs dispersed in −0.4 mV d-H2O were 2.7, −3.9, −8.7 and 8.2 mV, respectively, and these values were significantly decreased to −24.3, −23.6, −19.3 and −20.4 mV, respectively, after the addition of −15.4 mV of BS

Postchemoradiotherapy Pathologic Stage Classified by the American Joint Committee on the Cancer Staging System Predicts Prognosis of Patients with Locally Advanced Esophageal Squamous Cell Carcinoma

IntroductionTo determine whether the postchemoradiotherapy (post-CRT) pathologic stage predicts the outcomes of patients with locally advanced esophageal squamous cell carcinoma (ESCC) undergoing preoperative CRT followed by surgery.MethodsFrom three phase II trials of preoperative CRT for locally advanced ESCC, 140 patients were included. Preoperative CRT comprised twice weekly paclitaxel and cisplatin-based regimens and 40-Gy radiotherapy in 20 fractions. The post-CRT pathologic stage was classified according to the American Joint Committee on Cancer, 7th edition staging system. The prognostic effects of clinicopathologic factors were analyzed using Cox regression.ResultsWith a median follow-up of 61.9 months, the median progression-free survival (PFS) and overall survival (OS) of the entire cohort were 24.5 and 30.9 months, respectively. The post-CRT pathologic stage was 0 in 34.5%, I in 12.9%, II in 29.3%, III in 13.6%, and ypT0N1-2 in 6.4% of the patients. The median PFS was 47.2, 25.9, 16.0, 9.4, and 15.1 months, and the median OS was 57.4, 34.1, 26.2, 14.1, and 17.6 months for patients with post-CRT pathologic stage 0, I, II, III, and ypT0N1-2, respectively. In multivariate analysis, performance status (p < 0.001), tumor location (p = 0.016), and extranodal extension (p = 0.024) were independent prognostic factors for PFS, whereas performance status (p < 0.001) and post-CRT pathologic stage (p = 0.027) were independent prognostic factors for OS.ConclusionsThe post-CRT pathologic stage classified by American Joint Committee on Cancer, 7th edition staging system predicted the survival of locally advanced ESCC patients who underwent preoperative paclitaxel and cisplatin-based CRT followed by esophagectomy

A SUMO-regulated activation function controls synergy of c-Myb through a repressor–activator switch leading to differential p300 recruitment

Synergy between transcription factors operating together on complex promoters is a key aspect of gene activation. The ability of specific factors to synergize is restricted by sumoylation (synergy control, SC). Focusing on the haematopoietic transcription factor c-Myb, we found evidence for a strong SC linked to SUMO-conjugation in its negative regulatory domain (NRD), while AMV v-Myb has escaped this control. Mechanistic studies revealed a SUMO-dependent switch in the function of NRD. When NRD is sumoylated, the activity of c-Myb is reduced. When sumoylation is abolished, NRD switches into being activating, providing the factor with a second activation function (AF). Thus, c-Myb harbours two AFs, one that is constitutively active and one in the NRD being SUMO-regulated (SRAF). This double AF augments c-Myb synergy at compound natural promoters. A similar SUMO-dependent switch was observed in the regulatory domains of Sp3 and p53. We show that the change in synergy behaviour correlates with a SUMO-dependent differential recruitment of p300 and a corresponding local change in histone H3 and H4 acetylation. We therefore propose a general model for SUMO-mediated SC, where SUMO controls synergy by determining the number and strength of AFs associated with a promoter leading to differential chromatin signatures

Significance of Aurora B overexpression in hepatocellular carcinoma. Aurora B Overexpression in HCC

<p>Abstract</p> <p>Background</p> <p>To investigate the significance of Aurora B expression in hepatocellular carcinoma (HCC).</p> <p>Methods</p> <p>The <it>Aurora B </it>and <it>Aurora A </it>mRNA level was measured in 160 HCCs and the paired nontumorous liver tissues by reverse transcription-polymerase chain reaction. Mutations of the <it>p53 </it>and <it>β-catenin </it>genes were analyzed in 134 and 150 tumors, respectively, by direct sequencing of exon 2 to exon 11 of <it>p53 </it>and exon 3 of <it>β-catenin</it>. Anticancer effects of AZD1152-HQPA, an Aurora B kinase selective inhibitor, were examined in Huh-7 and Hep3B cell lines.</p> <p>Results</p> <p><it>Aurora B </it>was overexpressed in 98 (61%) of 160 HCCs and in all 7 HCC cell lines examined. The overexpression of <it>Aurora B </it>was associated with <it>Aurora A </it>overexpression (<it>P </it>= 0.0003) and <it>p53 </it>mutation (<it>P </it>= 0.002) and was inversely associated with <it>β</it>-<it>catenin </it>mutation (<it>P </it>= 0.002). <it>Aurora B </it>overexpression correlated with worse clinicopathologic characteristics. Multivariate analysis confirmed that <it>Aurora B </it>overexpression was an independent poor prognostic factor, despite its interaction with Aurora A overexpression and mutations of <it>p53 </it>and <it>β</it>-<it>catenin</it>. In Huh-7 and Hep3B cells, AZD1152-HQPA induced proliferation blockade, histone H3 (Ser10) dephosphorylation, cell cycle disturbance, and apoptosis.</p> <p>Conclusion</p> <p><it>Aurora B </it>overexpression is an independent molecular marker predicting tumor invasiveness and poor prognosis of HCC. Aurora B kinase selective inhibitors are potential therapeutic agents for HCC treatment.</p