bluuebunny/crossref_metadata_2025 huggingface dataset:
Cholesterol modulates the signaling of chemosensory bitter taste receptor T2R14 in human airway cells
Authors: Shaik Feroz Ahmed , Medapati Manoj Reddy , Chelikani Prashen
Published: October 2018

Bitter taste receptors (T2Rs) are a group of 25 chemosensory receptors expressed at significant levels in the human airways. In human airways, bitter taste receptor 14 (T2R14)-mediated physiological response in ameliorating obstructive airway disorders is an active area of investigation. Therefore, understanding various factors regulating the structure and function of T2R14 will be beneficial. We hypothesize that membrane lipids like cholesterol play a regulatory role in T2R14 signaling in airway cells. We confirmed the expression and signaling of T2R14 in primary human airway smooth muscle (HASM) cells and the human airway epithelial cell line (NuLi-1) using immunoblot analysis and intracellular calcium concentration mobilization experiments, respectively. Next, T2R14 signaling was examined in membrane cholesterol-altered environments by methyl-β-cyclodextrin or cholesterol oxidase treatments. In the cells analyzed, cholesterol depletion affected the agonist-induced T2R14 signaling, and cholesterol replenishment rescued its efficacy. An alternative approach for cholesterol depletion (with cholesterol oxidase pretreatment) also negatively affected the agonist potency at T2R14 in HASM cells. To understand the molecular mechanism of interaction between cholesterol and T2R14, we used site-directed mutagenesis coupled with functional assays and examined the role of putative cholesterol-binding motifs (CRAC and CARC) in T2R14. Functional characterization of wild-type and mutant T2R14 receptors suggests that amino acid residues K110, F236, and L239 are crucial in T2R14-cholesterol functional interaction. In conclusion, our results show that cholesterol influences the T2R14 signaling efficacy by forming direct interactions with the receptor and consequently plays a regulatory role in T2R14-mediated signaling in human airway cells.
Effect of Joint Geometrical Parameters on Hydraulic Fracture Network Propagation in Naturally Jointed Shale Reservoirs
Authors: Chong Zhaohui , Yao Qiangling , Li Xuehua
Published: October 2018

The presence of a significant amount of discontinuous joints results in the inhomogeneous nature of the shale reservoirs. The geometrical parameters of these joints exert effects on the propagation of a hydraulic fracture network in the hydraulic fracturing process. Therefore, mechanisms of fluid injection-induced fracture initiation and propagation in jointed reservoirs should be well understood to unleash the full potential of hydraulic fracturing. In this paper, a coupled hydromechanical model based on the discrete element method is developed to explore the effect of the geometrical parameters of the joints on the breakdown pressure, the number and proportion of hydraulic fractures, and the hydraulic fracture network pattern generated in shale reservoirs. The microparameters of the matrix and joint used in the shale reservoir model are calibrated through the physical experiment. The hydraulic parameters used in the model are validated through comparing the breakdown pressure derived from numerical modeling against that calculated from the theoretical equation. Sensitivity analysis is performed on the geometrical parameters of the joints. Results demonstrate that the HFN pattern resulting from hydraulic fracturing can be roughly divided into four types, i.e., crossing mode, tip-to-tip mode, step path mode, and opening mode. As β (joint orientation with respect to horizontal principal stress in plane) increases from 0° to 15° or 30°, the hydraulic fracture network pattern changes from tip-to-tip mode to crossing mode, followed by a gradual decrease in the breakdown pressure and the number of cracks. In this case, the hydraulic fracture network pattern is controlled by both γ (joint step angle) and β. When β is 45° or 60°, the crossing mode gains dominance, and the breakdown pressure and the number of cracks reach the lowest level. In this case, the HFN pattern is essentially dependent on β and d (joint spacing). As β reaches 75° or 90°, the step path mode is ubiquitous in all shale reservoirs, and the breakdown pressure and the number of the cracks both increase. In this case, β has a direct effect on the HFN pattern. In shale reservoirs with the same β, either decrease in k (joint persistency) and e (joint aperture) or increase in d leads to the increase in the breakdown pressure and the number of cracks. It is also found that changes in d and e result in the variation in the proportion of different types of hydraulic fractures. The opening mode of the hydraulic fracture network pattern is observed when e increases to 1.2 × 10−2 m.
Laboratory Performance Evaluation of HMA Modified with Various Types and Contents of Polymer
Authors: Baek Cheolmin , Lee Sangyum
Published: October 2018

Since asphalt binder modifiers for the performance improvement have both good and bad effects on the performance of asphalt pavements, it is important to consider all performance parameters of asphalt pavements for the development of modifiers. This paper evaluates the viscoelastic and plastic properties of four types of asphalt mixtures (three modified mixtures and one unmodified mixture) by laboratory tests, and then, the test results are employed to investigate the effects of modifiers. Test methods adopted in this study are the dynamic modulus test for linear viscoelastic model classified as nondefective test and tension test for constant crosshead rate test and cyclic load test and the triaxial compression test for plastic deformation classified as defective test. The performance for the fatigue failure at the real site’s pavement was evaluated by using the VECD‐FEP++. The performance of rutting for each mixture was evaluated by using the viscoplastic model from tension test and triaxial compression test proposed by NCHRP 1‐37 A MEPDG (AASHTO2004) and the rutting model. The findings from this study support general understanding of the effects of asphalt binder modifier on the fatigue cracking and rutting performance. When considering the performances of rutting and fatigue failure, K2 mixture is the best SBS‐modified material. The modified agent for K1 mixture has low performance than K2 mixture, and K4 mixture is good when the rutting is terribly occurred. But it needs serious caution to the failure.
Ketamine Infusion Used to Successfully Control Refractory Status Epilepticus in a Pregnant Patient
Authors: Talahma Murad , Sabharwal Vivek , Bukovskaya Yana , Khan Fawad
Published: October 2018

The management of SE during pregnancy is especially challenging to the treating physician. While antiepileptic medications might cause teratogenicity, SE can have significant morbidity and mortality on both the mother and the developing fetus. This case report demonstrated the successful use of ketamine infusion in the management of RSE in pregnancy without affecting the immediate outcome of pregnancy. The fetus survived this complicated ICU stay and outpatient follow-up was generally uncomplicated. The pregnancy was ended with a delivery of a normal female newborn.
Assessment of Blasting‐Induced Ground Vibration in an Open‐Pit Mine under Different Rock Properties
Authors: Yin Zhi-qiang , Hu Zu-xiang , Wei Ze-di , Zhao Guang-ming , Hai-feng Ma , Zhang Zhuo , Feng Rui-min
Published: October 2018

In an open‐pit mine slope, rock mass has multiple joint structures and blasting operations have an obvious influence on its stability. Therefore, accurately predicting the blasting vibration is necessary to ensure slope stability. In this study, the blasting vibration signals monitored at a blasting site with different rock masses were used to investigate the attenuation characteristics of blasting vibration through the peak particle velocity (PPV), frequency characteristics, and energy distribution of the blasting vibration signals analyzed with the time‐frequency processing method. The results demonstrated that the main vibration frequency of the blasting vibration of dolomite was wider than that of shale, and these main vibration frequencies occurred at 25 kHz and 14 kHz for dolomite and shale, respectively, at a distance of 50 m from the blast area to the vibration monitoring point. With an increase in the distance from 50 m to 200 m, the main vibration frequencies decreased to less than 5 Hz. With increasing joint degree, the attenuation rate of the vibration velocity and energy attenuation of the blasting vibration increase, indicating that the structural parameters of the rock mass (such as the number of joints) have a significant impact on the attenuation law of blasting vibration. Furthermore, a modified equation that can be used for predicting PPV was developed by considering the effect of the number of joints in the rock mass on the blasting vibration. For the same ground vibration readings, the correlation factor increased from 0.8 to 0.85 for the Nicholls‐USBM equation and the modified equation, respectively. The PPV of blasting under different rock masses of the Baideng open‐pit phosphorite mine was used to verify the modified equation. The results show that a modified equation can be used for predicting the PPV of blasting engineering in the Baideng phosphorite mine and that the prediction accuracy is acceptable.
Estimating the Relative Stiffness between a Hepatic Lesion and the Liver Parenchyma through Biomechanical Simulations of the Breathing Process
Authors: Martínez-Sanchis S. , Rupérez M. J. , Nadal E. , Pareja E. , Brugger S. , Borzacchiello D. , López-Andújar R. , Monserrat C.
Published: October 2018

In this paper, a method to in vivo estimate the relative stiffness between a hepatic lesion and the liver parenchyma is presented. This method is based on the finite element simulation of the deformation that the liver undergoes during the breathing process. Boundary conditions are obtained through a registration algorithm known as Coherent Point Drift (CPD), which compares the liver form in two phases of the breathing process. Finally, the relative stiffness of the tumour with respect to the liver parenchyma is calculated by means of a Genetic Algorithm, which does a blind search of this parameter. The relative stiffness together with the clinical information of the patient can be used to establish the type of hepatic lesion. The developed methodology was first applied to a test case, i.e., to a control case where the parameters were known, in order to verify its validity. After that, the method was applied to two real cases and low errors were obtained.
Effects of Tube Diameter and Length on Transparent Conductivity of Single-Walled Carbon Nanotube Network Films
Authors: Kuwahara Yuki , Hirai Takayoshi , Saito Takeshi
Published: October 2018

The effects of single-walled carbon nanotube (SWCNT) structures on the transparent conductivity of their network films have been investigated. SWCNTs with different average tube diameters of 1.3 nm, 1.7 nm, and 2.0 nm were processed at the same conditions. Then unit structure characterization was performed by determining the tube diameter, length, bundle thickness, and so on, before the fabrication of SWCNT network films by the filtration and transfer method using the dispersions. The result of the transparent conductivity measurements clearly showed better performance with a decrease in the tube diameter: that is, narrower SWCNTs form narrow bundles, and their dense network results in an increase in the total length of conduction pathways in the SWCNT network films with high transparency. Furthermore, the figure of merit and the percolation exponent for the transparent conductivity obtained by using the data fitting of the percolation model were also discussed in terms of the tube diameter and length.
Sexual Enhancing Effect of Anacardium occidentale in Stress-Exposed Rats by Improving Dopaminergic and Testicular Functions
Authors: Wattanathorn Jintanaporn , Prabsattroo Thawatchai , Somsapt Pichet , Sritragool Opass , Thukham-mee Wipawee , Muchimapura Supaporn
Published: October 2018

In this study, we aimed to assess the effect and possible underlying mechanism of Anacardium occidentale leaves extract on male sexual behaviors in stress-exposed rats. Male Wistar rats were orally given A. occidentale extract at doses of 25, 100, and 200 mg/kg BW before 12-hour-immobilization exposure for 14 days. Sexual behaviors, serum testosterone and corticosterone levels, TH-positive cells density in nucleus accumbens (NAc) and ventral tegmental area (VTA), MAO-B activity in NAc and medial preoptic area (MPOA), testis histology together with phosphodiesterase type-5 ( PDE-5) activity, and endothelial nitric oxide synthase (eNOS) expression in penis were evaluated after treatment. All doses of extract improved male sexual behaviors, suppressed MAO-B in NAc, enhanced TH-positive cells density in NAc, suppressed PDE-5 in penis, and enhanced interstitial cell of Leydig. The increase of serum testosterone, TH-positive cells density in VTA, eNOS expression in penis, and the decreased serum corticosterone were observed at some doses. Therefore, the sexual enhancing effect of extract occurred mainly via the improved dopaminergic and testicular functions. PDE-5 suppression in penis also played the role especially in the increased intromission behavior. Therefore, A. occidentale leaves extract is the potential protective agent against sexual dysfunction. However, further researches are necessary.
Relevance of Trypanothione Reductase Inhibitors on Trypanosoma cruzi Infection: A Systematic Review, Meta‐Analysis, and In Silico Integrated Approach
Authors: Mendonça Andréa Aparecida Santos , Coelho Camila Morais , Veloso Marcia Paranho , Caldas Ivo Santana , Gonçalves Reggiani Vilela , Teixeira Antônio Lucio , de Miranda Aline Silva , Novaes Rômulo Dias
Published: October 2018

Due to the rudimentary antioxidant defenses in Trypanosoma cruzi, disruptors of redox balance are promising candidates for new antitrypanosomal drugs. We developed an integrated model based on systematic review, meta‐analyses, and molecular modeling to evaluate the effect of trypanothione reductase (TR) inhibitors in T. cruzi infections. Our findings indicated that the TR inhibitors analyzed were effective in reducing parasitemia and mortality due to Trypanosoma cruzi infection in animal models. The most investigated drugs (clomipramine and thioridazine) showed no beneficial effects on the occurrence of infection‐related electrocardiographic abnormalities or the affinity and density of cardiac β‐adrenergic receptors. The affinity between the tested ligands and the active site of TR was confirmed by molecular docking. However, the molecular affinity score was unable to explain TR inhibition and T. cruzi death in vitro or the antiparasitic potential of these drugs when tested in preclinical models of T. cruzi infection. The divergence of in silico, in vitro, and in vivo findings indicated that the anti‐T. cruzi effects of the analyzed drugs were not restricted to TR inhibition. As in vivo studies on TR inhibitors are still scarce and exhibit methodological limitations, mechanistic and highly controlled studies are required to improve the quality of evidence.
Combination of Coenzyme Q10 Intake and Moderate Physical Activity Counteracts Mitochondrial Dysfunctions in a SAMP8 Mouse Model
Authors: Andreani C. , Bartolacci C. , Guescini M. , Battistelli M. , Stocchi V. , Orlando F. , Provinciali M. , Amici A. , Marchini C. , Tiano L. , Orlando P. , Silvestri S.
Published: October 2018

Aging skeletal muscles are characterized by a progressive decline in muscle mass and muscular strength. Such muscular dysfunctions are usually associated with structural and functional alterations of skeletal muscle mitochondria. The senescence‐accelerated mouse‐prone 8 (SAMP8) model, characterized by premature aging and high degree of oxidative stress, was used to investigate whether a combined intervention with mild physical exercise and ubiquinol supplementation was able to improve mitochondrial function and preserve skeletal muscle health during aging. 5‐month‐old SAMP8 mice, in a presarcopenia phase, have been randomly divided into 4 groups (n = 10): untreated controls and mice treated for two months with either physical exercise (0.5 km/h, on a 5% inclination, for 30 min, 5/7 days per week), ubiquinol 10 (500 mg/kg/day), or a combination of exercise and ubiquinol. Two months of physical exercise significantly increased mitochondrial damage in the muscles of exercised mice when compared to controls. On the contrary, ubiquinol and physical exercise combination significantly improved the overall status of the skeletal muscle, preserving mitochondrial ultrastructure and limiting mitochondrial depolarization induced by physical exercise alone. Accordingly, combination treatment while promoting mitochondrial biogenesis lowered autophagy and caspase 3‐dependent apoptosis. In conclusion, the present study shows that ubiquinol supplementation counteracts the deleterious effects of physical exercise‐derived ROS improving mitochondrial functionality in an oxidative stress model, such as SAMP8 in the presarcopenia phase.
Role of Leptin/Osteopontin Axis in the Function of Eosinophils in Allergic Rhinitis with Obesity
Authors: Liu Wenlong , Zeng Qingxiang , Chen Yanqiu , Luo Ren Zhong
Published: October 2018

Background. Allergic rhinitis (AR) is characterized by tissue and blood eosinophilia. Previous studies showed enhanced eosinophilia in allergic rhinitis patients with obesity, suggesting an association between obesity and eosinophilia. However, the interaction and mechanism between obesity and eosinophilia is still unclear.Methods. We recruited thirty AR children and 30 controls in this study. Expression of leptin and osteopontin (OPN) proteins in serum was detected, and correlation analysis with eosinophilia was performed. The effect of leptin or OPN on eosinophil apoptosis, adhesion, migration, and activation of eosinophil was examined. Ovalbumin-sensitized mice were established to prove the role of obesity on eosinophil regulation by leptin and OPN.Results. We found that upregulated serum and nasal leptin and OPN expression in AR were positively correlated with eosinophilia and eosinophil cationic protein levels. Leptin or OPN inhibited eosinophil apoptosis, demonstrated as inhibited DNA fragmentation and phosphatidylserine (PS) redistribution (P<0.05). Leptin and OPN promote expression of cluster of differentiation 18 (CD-18) and intercellular adhesion molecule 1 (ICAM-1) and inhibit expression of ICAM-1 and L-selectin by eosinophils, which contribute to the adhesion of eosinophils. Leptin and OPN mediated migration and activation of eosinophil through phosphatidylinositol-3-OH kinase (PI3K) pathway. Obese AR mice presented with more severe eosinophilia and symptoms compared with nonobese AR mice or control mice. Immunochemistry staining of leptin and OPN of nasal turbinate in obese AR mice was also stronger than those in nonobese AR mice or control mice. Anti-OPN, anti-leptin, and anti-α4 treatments reduce nasal eosinophilia inflammation and clinical symptoms in model mice.Conclusion. Our results suggested that in an obese state, upregulation of leptin and OPN regulates apoptosis, adhesion, migration, and activation of eosinophils, and this process may be mediated by the PI3K and anti-α4 pathways.
Impact of Unilateral Orbital Radiotherapy on the Structure and Function of Bilateral Human Meibomian Gland
Authors: Chen Di , Liu Xiaowei , Li Ying , Guan Hui , Zhang Fuquan
Published: October 2018

Background. Radiotherapy (RT) has widely been used to treat ocular tumors, yet the impact of orbital radiation to the meibomian gland has rarely been studied. Our study aims at evaluating the bilateral meibomian gland structure and function 12 months after unilateral orbital RT in patients with ocular tumors. Methods. An observational case-control study. A total of 10 eyes 12 months after unilateral orbital RT, 10 contralateral eyes, and 10 normal controls were enrolled. Meibomian gland loss (MGL), lipid layer thickness (LLT), tear film breakup time (TBUT), Schirmer I test, and cornea fluorescein staining were measured. Ocular Surface Disease Index (OSDI) of the RT patients was assessed and compared with normal controls. Results. The cumulative median radiotherapy dosage for the patients was 45 (range: 30, 70) Gy. The OSDI score of the patients was significantly greater than the normal controls (22.92 (range: 10.42, 37.50) vs 6.25 (range: 2.08, 10.42), p≤0.001). Significant differences of upper MGL, lower MGL, LLT, and TBUT were found between the diseased eyes and normal controls (37.79% (range: 12.87, 92.41) vs 12.63% (range: 6.13, 42.34), p=0.007; 61.31% (range: 44.67, 87.98) vs 15.53% (range: 7.65, 45.13), p≤0.001; 40 ICU (range: 23, 100) vs 81.5 ICU (range: 54, 100), p=0.007; 3.5 s (range: 2, 8) vs 6.5 s (range: 5, 10), p=0.002). The upper MGL and TBUT of the contralateral eyes were also considerably damaged compared with normal controls. Lower eyelid MGL and cornea staining score of the diseased eye were significantly correlated with radiation dosage (r = 0.913 and 0.680; p=0.001 and 0.044, respectively). Conclusion. Orbital radiotherapy could cause significant damage to the meibomian gland structure and function, not only the diseased eyes but also the contralateral eyes.
Extraction of Earth Surface Texture Features from Multispectral Remote Sensing Data
Authors: Zhang Zhenxing , Gao Feng , Ma Bin , Zhang Zhiqiang
Published: October 2018

Earth surface texture features referring to as visual features of homogeneity in remote sensing images are very important to understand the relationship between surface information and surrounding environment. Remote sensing data contain rich information of earth surface texture features (image gray reflecting the spatial distribution information of texture features, for instance). Here, we propose an efficient and accurate approach to extract earth surface texture features from remote sensing data, called gray level difference frequency spatial (GLDFS). The gray level difference frequency spatial approach is designed to extract multiband remote sensing data, utilizing principle component analysis conversion to compress the multispectral information, and it establishes the gray level difference frequency spatial of principle components. In the end, the texture features are extracted using the gray level difference frequency spatial. To verify the effectiveness of this approach, several experiments are conducted and indicate that it could retain the coordination relationship among multispectral remote sensing data, and compared with the traditional single-band texture analysis method that is based on gray level co-occurrence matrix, the proposed approach has higher classification precision and efficiency.
Temozolomide Induces Senescence and Repression of DNA Repair Pathways in Glioblastoma Cells via Activation of ATR–CHK1, p21, and NF-κB
Authors: Aasland Dorthe , Götzinger Laura , Hauck Laura , Berte Nancy , Meyer Jessica , Effenberger Melanie , Schneider Simon , Reuber Emelie E. , Roos Wynand P. , Tomicic Maja T. , Kaina Bernd , Christmann Markus
Published: October 2018

The DNA-methylating drug temozolomide, which induces cell death through apoptosis, is used for the treatment of malignant glioma. Here, we investigate the mechanisms underlying the ability of temozolomide to induce senescence in glioblastoma cells. Temozolomide-induced senescence was triggered by the specific DNA lesion O6-methylguanine (O6MeG) and characterized by arrest of cells in the G2–M phase. Inhibitor experiments revealed that temozolomide-induced senescence was initiated by damage recognition through the MRN complex, activation of the ATR/CHK1 axis of the DNA damage response pathway, and mediated by degradation of CDC25c. Temozolomide-induced senescence required functional p53 and was dependent on sustained p21 induction. p53-deficient cells, not expressing p21, failed to induce senescence, but were still able to induce a G2–M arrest. p14 and p16, targets of p53, were silenced in our cell system and did not seem to play a role in temozolomide-induced senescence. In addition to p21, the NF-κB pathway was required for senescence, which was accompanied by induction of the senescence-associated secretory phenotype. Upon temozolomide exposure, we found a strong repression of the mismatch repair proteins MSH2, MSH6, and EXO1 as well as the homologous recombination protein RAD51, which was downregulated by disruption of the E2F1/DP1 complex. Repression of these repair factors was not observed in G2–M arrested p53-deficient cells and, therefore, it seems to represent a specific trait of temozolomide-induced senescence.

Significance:

These findings reveal a mechanism by which the anticancer drug temozolomide induces senescence and downregulation of DNA repair pathways in glioma cells.
Anti-MET VHH Pool Overcomes MET-Targeted Cancer Therapeutic Resistance
Authors: Su Zhipeng , Han Yunchun , Sun Qichen , Wang Xiaoxiao , Xu Ting , Xie Wei , Huang Xing
Published: October 2018

Receptor tyrosine kinase MET and its ligand hepatocyte growth factor (HGF) play crucial roles in many human malignancies. Numerous drugs have been developed against kinase center of MET or HGF-mediated activation; however, the outcomes in patients are not so promising. Increasing evidence show that MET has kinase-independent effects on tumorigenesis and dissemination, which explains the low efficacy in kinase inhibition-based strategy. VHH is the recombinant variable region of Camelid heavy-chain antibody. As a nanoscale antigen-binding unit, VHH has become an appealing drug candidate in cancer therapy. In our study, we choose a novel strategy to construct an anti-MET VHH pool against the whole ecto-domain of MET. Comparing to monoclonal antibody or single VHH, the anti-MET VHH pool strongly promotes MET degradation through Clathrin-dependent endo-lysosomal pathway. Thus, the anti-MET VHH pool not only blocks kinase activity of MET, but also reduces protein level of MET. As a consequence, anti-MET VHH pool dramatically suppresses cancer cell proliferation, viability, and colony formation in vitro, and inhibits tumorigenesis and growth in mice. Taken together, VHH pool-based strategy greatly improves MET-targeted therapeutic effects on cancer.
Panitumumab Provides Better Survival Outcomes Compared to Cetuximab for Metastatic Colorectal Cancer Patients Treated with Prior Bevacizumab within 6 Months
Authors: Hayashi Kaori , Mitani Seiichiro , Taniguchi Hiroya , Yasui Hirofumi , Muro Kei , Mori Keita , Gotoda Takuji , Yamazaki Kentaro
Published: October 2018

Objective: Anti-epithelial growth factor receptor (EGFR) antibodies cetuximab (Cmab) and panitumumab (Pmab) have shown survival benefit for metastatic colorectal cancer (mCRC) patients. This study aimed to compare Pmab and Cmab according to the interval between bevacizumab discontinuation and anti-EGFR antibody initiation (bevacizumab-free interval; BFI). Methods: We retrospectively evaluated mCRC patients who received Cmab or Pmab in combination with irinotecan at two institutions. Inclusion criteria were histologically confirmed mCRC, with KRAS exon 2 wild-type tumor, refractory or intolerant to fluoropyrimidines, oxali platin, and irinotecan. Results: One-hundred-seventy-eight patients fulfilled the eligibility criteria. Among them, there was no significant difference in overall survival (OS) and progression-free survival (PFS) between the Pmab (n = 44) and Cmab groups (n = 134). Of 132 patients with BFI < 6 months, the median OS was 13.3 and 11.5 months in the Pmab (n = 39) and Cmab (n = 93) groups, respectively (p = 0.043). The median PFS was 5.8 and 4.9 months in the Pmab and Cmab groups, respectively (p = 0.055). Multivariate analysis for OS confirmed the superiority of Pmab. Conclusion: Pmab showed more favorable outcomes in patients treated with bevacizumab within the last 6 months. The interval between prior bevacizumab and subsequent anti-EGFR therapy may be useful for determining the optimal anti-EGFR therapy.
Glycine Induces Migration of Microglial BV-2 Cells via SNAT-Mediated Cell Swelling
Authors: Kittl Michael , Dobias Heidemarie , Beyreis Marlena , Kiesslich Tobias , Mayr Christian , Gaisberger Martin , Ritter Markus , Kerschbaum Hubert H. , Jakab Martin
Published: October 2018

Background/Aims: The neutral, non-essential amino acid glycine has manifold functions and effects under physiological and pathophysiological conditions. Besides its function as a neurotransmitter in the central nervous system, glycine also exerts immunomodulatory effects and as an osmolyte it participates in cell volume regulation. During phagocytosis, glycine contributes to (local) cell volume-dependent processes like lamellipodium formation. Similar to the expansion of the lamellipodium we assume that glycine also affects the migration of microglial cells in a cell volume-dependent manner. Methods: Mean cell volume (MCV) and cell migration were determined using flow cytometry and trans-well migration assays, respectively. Electrophysiological recordings of the cell membrane potential (Vmem) and swelling-dependent chloride (Cl-) currents (IClswell, VSOR, VRAC) were performed using the whole-cell patch clamp technique. Results: In the murine microglial cell line BV-2, flow cytometry analysis revealed that glycine (5 mM) increases the MCV by ∼9%. The glycine-dependent increase in MCV was suppressed by the partial sodium-dependent neutral amino acid transporter (SNAT) antagonist MeAIB and augmented by the Cl- current blocker DCPIB. Electrophysiological recordings showed that addition of glycine activates a Cl- current under isotonic conditions resembling features of the swelling-activated Cl- current (IClswell). The cell membrane potential (Vmem) displayed a distinctive time course after glycine application; initially, glycine evoked a rapid depolarization mediated by Na+-coupled glycine uptake via SNAT, followed by a further gradual depolarization, which was fully suppressed by DCPIB. Interestingly, glycine significantly increased migration of BV-2 cells, which was suppressed by MeAIB, suggesting that SNAT is involved in the migration process of microglial cells. Conclusion: We conclude that glycine acts as a chemoattractant for microglial cells presumably by a cell volume-dependent mechanism involving SNAT-mediated cell swelling.
RNA-Sequencing Data Reveal a Prognostic Four-lncRNA-Based Risk Score for Bladder Urothelial Carcinoma: An in Silico Update
Authors: He Rong-Quan , Huang Zhi-Guang , Li Tian-Yu , Wei Yan-Ping , Chen Gang , Lin Xing-Gu , Wang Qiu-Yan
Published: October 2018

Background/Aims: Current practical advances in high-throughput data technologies including RNA-sequencing have led to the identification of long non-coding RNAs (lncRNAs) for potential clinical application against bladder urothelial cancer (BLCA). However, most previous studies focused on the clinical value of individual lncRNAs, which has limited the potential for future clinical application. Methods: In this study, RNA-sequencing data of lncRNAs was downloaded from The Cancer Genome Atlas database. Risk score was constructed based on survival-associated lncRNAs identified using differential expression analysis as well as univariate and multivariate Cox proportional hazards regression analysis. Receiver operating characteristic and Kaplan-Meier curve analyses were employed to evaluate the clinical and prognostic value of risk scores. Bioinformatics analyses were used to investigate the potential mechanisms of newly identified lncRNAs. Results: Among 2,127 differentially expressed lncRNAs (DELs), four new lncRNAs (AC145124.1, AC010168.2, MIR200CHG, and AC098613.1) showed valuable prognostic effects in BLCA patients. More importantly, the four-DEL-based risk score had the potential to become an independent marker for the survival status prediction of BLCA patients. Distinct co-expressed genes and signaling pathways were identified when BLCA was categorized into low- and high-risk groups. Furthermore, a protein-coding gene, HIST4H4 was found only 68 bp from the AC010168.2 DEL. HIST4H4 expression level was evidently up-regulated and positively correlated with AC010168.2 in BLCA patients. Conclusion: This in silico investigation pioneers the future investigation of the utility of prognostic lncRNAs for BLCA.
Periodic Mechanical Stress Induces Extracellular Matrix Expression and Migration of Rat Nucleus Pulposus Cells Through Src-GIT1-ERK1/2 Signaling Pathway
Authors: Gao Gongming , Li Haibo , Huang Yongjing , Yin Jianjian , Jiang Yuqing , Xu Nanwei , Zhou Dong , Nong Luming , Ren Kewei
Published: October 2018

Background/Aims: Periodic mechanical stress has been shown to promote extracellular matrix (ECM) synthesis and cell migration of nucleus pulposus (NP) cells, however, the mechanisms need to be fully elucidated. The present study aimed to investigate the signal transduction pathway in the regulation of NP cells under periodic mechanical stress. Methods: Primary rat NP cells were isolated and seeded on glass slides, and then treated in our self-developed periodic stress field culture system. To further explore the mechanisms, data were analyzed by scratch-healing assay, quantitative reverse transcription polymerase chain reaction (RT-qPCR) analysis, western blotting, and co-immunoprecipitation assay. Results: Under periodic mechanical stress, the mRNA expression of ECM collagen 2A1 (Col2A1) and aggrecan, and migration of NP cells were significantly increased (P < 0.05 for each), associating with increases in the phosphorylation of Src, GIT1, and ERK1/2 (P < 0.05 for each). Pretreatment with the Src inhibitor PP2 reduced periodic mechanical stress-induced ECM synthesis and cell migration of NP cells (P < 0.05 for each), while the phosphorylation of GIT1 and ERK1/2 were inhibited. ECM synthesis, cell migration, and phosphorylation of ERK1/2 were inhibited after pretreatment with the small interfering RNA for GIT1 in NP cells under periodic mechanical stress (P < 0.05 for each), whereas the phosphorylation of Src was not affected. Pretreatment with the ERK1/2 inhibitor PD98059 reduced periodic mechanical stress-induced ECM synthesis and cell migration of NP cells (P < 0.05 for each). Co-immunoprecipitation assay showed that there was a direct interaction between Src and GIT1 and between GIT1 and ERK1/2. Conclusion: In conclusion, periodic mechanical stress induced ECM expression and migration of NP cells via Src-GIT1-ERK1/2 signaling pathway, playing an important role in regulation of NP cells.
Knockdown of MicroRNA-1 in the Hippocampus Ameliorates Myocardial Infarction Induced Impairment of Long-Term Potentiation
Authors: Ma Ji-Chao , Duan Ming-Jing , Li Ke-Xin , Biddyut Das , Zhang Shuai , Yan Mei-Ling , Yang Lin , Jin Zhuo , Zhao Hong-Mei , Huang Si-Yu , Sun Qiang , Su Dan , Xu Yi , Pan Yong-Hui , Ai Jing
Published: October 2018

Backgrounds/Aims: It has been reported that myocardial infarction (MI) is a risk factor for vascular dementia. However, the molecular mechanism remains largely unknown. Methods: MI mice were generated by ligation of the left coronary artery (LCA) for 4 weeks. Passive and active avoidance tests were performed to evaluate the cognitive ability of MI mice. A theta-burst stimulation (TBS) protocol was applied to elicit long-term potentiation (LTP) of the perforant pathway-dentate gyrus synapse (PP-DG). Western blot analysis was employed to assess protein levels. Results: In this study, we demonstrated that after 4 weeks of MI, C57BL/6 mice had significantly impaired memory. Compared with the sham group, in vivo physiological recording in the MI group revealed significantly decreased amplitude of population spikes (PS) with no effect on the latency and duration of the stimulus-response curve. The amplitude of LTP was markedly decreased in the MI group compared with the sham group. Further examination showed that the expression of the TBS-LTP-related proteins BDNF, GluA1 and phosphorylated GluA1 were all decreased in the MI group compared with those in the sham group. Strikingly, all these changes were prevented by hippocampal stereotaxic injection of an anti-miR-1 oligonucleotide fragment carried by a lentivirus vector (lenti-pre-AMO-1). Conclusion: MI induced cognitive decline and TBS-LTP impairment, and decreased BDNF and GluA1 phosphorylation levels from overexpression of miR-1ated were involved in this process.
Lack of Cardiac Improvement After Cardiosphere-Derived Cell Transplantation in Aging Mouse Hearts
Authors: Zhao Zhen-Ao , Han Xinglong , Lei Wei , Li Jingjing , Yang Zhuangzhuang , Wu Jie , Yao Mengchao , Lu Xing-Ai , He Lingjuan , Chen Yihuan , Zhou Bin , Hu Shijun
Published: October 2018

Rationale:

Aging is one of the most significant risk factors for cardiovascular diseases, and the incidence of myocardial ischemia increases dramatically with age. Some studies have reported that cardiosphere-derived cells (CDCs) could benefit the injured heart. Nevertheless, the convincing evidence on CDC-induced improvement of aging heart is still limited.

Objective:

In this study, we tested whether the CDCs isolated from neonatal mice could benefit cardiac function in aging mice.

Methods and Results:

We evaluated cardiac function of PBS- (n=15) and CDC-injected (n=19) aging mice. Echocardiography indicated that left ventricular (LV) ejection fraction (57.46%±3.57% versus 57.86%±2.44%) and LV fraction shortening (30.67%±2.41% versus 30.51%±1.78%) showed similar values in PBS- and CDC-injected mice. The diastolic wall thickness of LV was significantly increased after CDC injection, resulting in reduced diastolic LV volume. The pulse-wave Doppler and tissue Doppler imaging indicated that aging mice receiving PBS or CDC injection presented similar values of the peak early transmitral flow velocity, the peak late transmitral flow velocity, the ratio of the peak early transmitral flow velocity to the peak late transmitral flow velocity, and the ratio of the peak early transmitral flow velocity to the peak early diastolic mitral annular velocity, respectively. Pressure-volume loop experiment indicated that the LV end-diastolic pressure-volume relationship and end-systolic pressure-volume relationship were comparable in both PBS- and CDC-injected mice. Postmortem analysis of aging mouse hearts showed similar fibrotic degree in the 2 groups. In addition, the aging markers showed comparable expression levels in both PBS- and CDC-injected mice. The systemic aging performance measures, including exercise capacity, hair regrowth capacity, and inflammation, showed no significant improvement in CDC-injected mice. Finally, the telomere length was comparable between PBS- and CDC-injected mice.

Conclusions:

Together, these results indicate that CDCs do not improve heart function and systemic performances in aging mice.
Vago-Splenic Axis in Signal Transduction of Remote Ischemic Preconditioning in Pigs and Rats
Authors: Lieder Helmut Raphael , Kleinbongard Petra , Skyschally Andreas , Hagelschuer Helene , Chilian William M. , Heusch Gerd
Published: October 2018

Rationale:

The signal transduction of remote ischemic conditioning is still largely unknown.

Objective:

Characterization of neurohumoral signal transfer and vago-splenic axis in remote ischemic preconditioning (RIPC).

Methods and Results:

Anesthetized pigs were subjected to 60 minutes of coronary occlusion and 180 minutes of reperfusion (placebo+ischemia/reperfusion [PLA+I/R]). RIPC was induced by 4×5/5 minutes of hindlimb I/R 90 minutes before coronary occlusion (RIPC+I/R). Arterial blood samples were taken after placebo or RIPC before I/R. In subgroups of pigs, bilateral cervical vagotomy, splenectomy, or splenic denervation were performed before PLA+I/R or RIPC+I/R, respectively. In pigs with RIPC+I/R, infarct size (percentage of area at risk) was less than in those with PLA+I/R (23±12% versus 45±8%); splenectomy or splenic denervation abrogated (splenectomy+RIPC+I/R: 38±15%; splenic denervation+RIPC+I/R: 43±5%), and vagotomy attenuated (vagotomy+RIPC+I/R: 36±11%) RIPC protection. RIPC increased phosphorylation of STAT3 (signal transducer and activator of transcription 3) in left ventricular biopsies taken at early reperfusion. Splenectomy or splenic denervation, but not vagotomy, abolished this increased phosphorylation. In rats with vagotomy, splenectomy, or splenic denervation, RIPC (3×5/5 minutes of hindlimb occlusion/reperfusion) or placebo was performed, respectively. Hearts were isolated, saline perfused, and subjected to 30/120-minute global I/R. With RIPC, infarct size (percentage of ventricular mass) was less (20±7%) than with placebo (37±6%), and vagotomy, splenectomy, or splenic denervation abrogated RIPC protection (38±12%, 36±9%, and 36±7%), respectively. Rat spleens were isolated, saline perfused, and splenic effluate (SEff) was sampled after infusion with carbachol (SEff
carbachol
) or saline (SEff
saline
). Pig plasma or SEff was infused into isolated perfused rat hearts subjected to global I/R. Infarct size was less with infusion of RIPC+I/R
plasma
+ (24±6%) than with PLA+I/R
plasma
(40±8%), vagotomy+PLA+I/R
plasma
(39±11%), splenectomy+PLA+I/R
plasma
(35±8%), vagotomy+RIPC+I/R
plasma
(40±9%), splenectomy+RIPC+I/R
plasma
(33±9%), or splenic denervation+RIPC+I/R
plasma
(39±8%), respectively. With infusion of SEff
carbachol
, infarct size was less than with infusion of SEff
saline
(24 [19–27]% versus 35 [32–38]%).

Conclusions:

Activation of a vago-splenic axis is causally involved in RIPC cardioprotection.
Cerebral Cavernous Malformations Develop Through Clonal Expansion of Mutant Endothelial Cells
Authors: Detter Matthew R. , Snellings Daniel A. , Marchuk Douglas A.
Published: October 2018

Rationale:

Vascular malformations arise in vessels throughout the entire body. Causative genetic mutations have been identified for many of these diseases; however, little is known about the mutant cell lineage within these malformations.

Objective:

We utilize an inducible mouse model of cerebral cavernous malformations (CCMs) coupled with a multicolor fluorescent reporter to visualize the contribution of mutant endothelial cells (ECs) to the malformation.

Methods and Results:

We combined a Ccm3 mouse model with the confetti fluorescent reporter to simultaneously delete
Ccm3
and label the mutant EC with 1 of 4 possible colors. We acquired Z-series confocal images from serial brain sections and created 3-dimensional reconstructions of entire CCMs to visualize mutant ECs during CCM development. We observed a pronounced pattern of CCMs lined with mutant ECs labeled with a single confetti color (n=42). The close 3-dimensional distribution, as determined by the nearest neighbor analysis, of the clonally dominant ECs within the CCM was statistically different than the background confetti labeling of ECs in non-CCM control brain slices as well as a computer simulation (
P
<0.001). Many of the small (<100 μm diameter) CCMs consisted, almost exclusively, of the clonally dominant mutant ECs labeled with the same confetti color, whereas the large (>100 μm diameter) CCMs contained both the clonally dominant mutant cells and wild-type ECs. We propose of model of CCM development in which an EC acquires a second somatic mutation, undergoes clonal expansion to initiate CCM formation, and then incorporates neighboring wild-type ECs to increase the size of the malformation.

Conclusions:

This is the first study to visualize, with single-cell resolution, the clonal expansion of mutant ECs within CCMs. The incorporation of wild-type ECs into the growing malformation presents another series of cellular events whose elucidation would enhance our understanding of CCMs and may provide novel therapeutic opportunities.
Markers of Basement Membrane Remodeling Are Associated With Higher Mortality in Patients With Known Atherosclerosis
Authors: Holm Nielsen Signe , Tengryd Christoffer , Edsfeldt Andreas , Brix Susanne , Genovese Federica , Bengtsson Eva , Karsdal Morten , Leeming Diana J. , Nilsson Jan , Goncalves Isabel
Published: October 2018

Background

Patients with atherosclerosis have a high risk of cardiovascular events and death. Atherosclerosis is characterized by accumulation of lipids, cells and extracellular matrix proteins in the intima. We hypothesized that dysregulated remodeling of the basement membrane proteins may be associated with clinical outcomes in patients with atherosclerosis.

Methods and Results

Neoepitope fragments of collagen type
IV
(C4M) and laminin (
LG
1M) were assessed by
ELISA
s in serum from 787 endarterectomy patients.
Matrix metalloproteinase
s were measured using proximity extension assay and correlated to C4M and
LG
1M levels using Spearman correlations. A total of 473 patients were followed up for 6 years using national registers, medical charts, and telephone interviews. The incidence of
cardiovascular
events,
cardiovascular
mortality, and all‐cause mortality were associated to levels of C4M and
LG
1M using Kaplan–Meier curves and Cox regression analyses. A total of 101 patients had
cardiovascular
events, 39 died of
cardiovascular
mortality, and 64 patients died from all‐cause mortality. C4M levels were increased in patients with symptomatic carotid atherosclerotic disease before surgery (
P
=0.048). High C4M and
LG
1M levels were associated with increased risk of all‐cause mortality (
P
=0.020 and 0.031, respectively) and predicted all‐cause death together with glomerular filtration rate and diabetes mellitus.

Conclusions

High
LG
1M and C4M levels were associated with all‐cause mortality, together with glomerular filtration rate and diabetes mellitus. These novel biomarkers need further evaluation but might be tools to identify high‐risk patients.
8‐Aminoguanine Induces Diuresis, Natriuresis, and Glucosuria by Inhibiting Purine Nucleoside Phosphorylase and Reduces Potassium Excretion by Inhibiting Rac1
Authors: Jackson Edwin K. , Mi Zaichuan , Kleyman Thomas R. , Cheng Dongmei
Published: October 2018

Background

8‐Aminoguanosine and 8‐aminoguanine are K
+
‐sparing natriuretics that increase glucose excretion. Most effects of 8‐aminoguanosine are due to its metabolism to 8‐aminoguanine. However, the mechanism by which 8‐aminoguanine affects renal function is unknown and is the focus of this investigation.

Methods and Results

Because 8‐aminoguanine has structural similarities with inhibitors of the epithelial sodium channel (ENaC), Na
+
/H
+
exchangers, and adenosine A
1
receptors, we examined the effects of 8‐aminoguanine on
EN
aC activity in mouse collecting duct cells, on intracellular
pH
of human proximal tubular epithelial cells, on responses to a selective A
1
‐receptor agonist in vivo, and on renal excretory function in A
1
‐receptor knockout rats. These experiments showed that 8‐aminoguanine did not block
EN
aC, Na
+
/H
+
exchangers, or A
1
receptors. Because Rac1 enhances activity of mineralocorticoid receptors and some guanosine analogues inhibit Rac1, we examined the effects of 8‐aminoguanine on Rac1 activity in mouse collecting duct cells. Rac1 activity was significantly inhibited by 8‐aminoguanine. Because in vitro 8‐aminoguanine is a purine nucleoside phosphorylase (
PNP
ase) inhibitor, we examined the effects of a natriuretic dose of 8‐aminoguanine on urinary excretion of
PNP
ase substrates and products. 8‐Aminoguanine increased and decreased, respectively, urinary excretion of
PNP
ase substrates and products. Next we compared in rats the renal effects of intravenous doses of 9‐deazaguanine (
PNP
ase inhibitor) versus 8‐aminoguanine. 8‐Aminoguanine and 9‐deazaguanine induced similar increases in urinary Na
+
and glucose excretion, yet only 8‐aminoguanine reduced K
+
excretion. Nsc23766 (Rac1 inhibitor) mimicked the effects of 8‐aminoguanine on K
+
excretion.

Conclusions

8‐Aminoguanine increases Na
+
and glucose excretion by blocking
PNP
ase and decreases K
+
excretion by inhibiting Rac1.